WO2010052512A2

WO2010052512A2 - Process and apparatus for implementing thermodynamic cycles

Info

Publication number: WO2010052512A2
Application number: PCT/HU2009/000092
Authority: WO
Inventors: György Sándor JAKAB
Original assignee: RINYU, Ferenc György; KISS, László Gábor
Priority date: 2008-11-05
Filing date: 2009-11-04
Publication date: 2010-05-14
Also published as: WO2010052512A3

Abstract

In the process according to the invention volume capacities of working spaces (72, 95, 74, 96) are changed; expandable working medium is flowing between the working spaces (72, 74, 95, 96), and heat - transfer and / or heat-removal is carried out; wherein the volume capacities of the co-operating working spaces are changed in about a 180 degree counter- stroke, the working medium is driven from a decreasing volume capacity working space into an increasing volume capacity working space, in an order, which complies with the different stages of the thermodynamic cycle, and every stage of the thermodynamic cycle is realized separately, in a way, that always the same stage of the cycle should take place between two working spaces. The apparatus for implementation of the process contains working spaces (72, 74, 95, 96) with variable volume capacities and valves (81, 82, 88, 89, 98, 99, 101, 102) between the working spaces, the elements changing the volume capacities are interlocked with each other, the individual working spaces (72, 74, 95, 96) are connected in series and the last working space (96) is connected to the first one (72).

Description

PROCESS AND APPARATUS FOR IMPLEMENTING THERMODYNAMIC CYCLES

Object of the present invention is a process for implementing thermodynamic cycles, wherein volume capacities of working spaces are changed; expandable working medium is flowing between the working spaces, and heat-transfer and/or heat-removal is carried out. A further object of the invention is an apparatus for the implementation of this process.

It is well-known, that heat-engines are caloric (thermal) engines, which can convert thermal energy into mechanical work. Heat-pumps and those types of refrigerating-machines, which operate using the thermodynamic principles, belong to the group of the caloric engines, as well. Caloric engines - during their operation - are realizing a sort of cyclic process. An ideal heat engine operates according to a thermodynamic cycle known as the 'Carnot-cycle'.

Presently, those types of heat engines represent the most effective heat engine alternatives, which operate according to the Stirling cycle; - these are even realizable within the circumstances of the real life, and they have the greatest thermal power efficiency. Figure 1 shows a P - V diagram, where the theoretical Stirling cycle is shown with dashed line. The size of the enclosed area is proportional to the amount of work carried out by the gas. In order to be able to achieve a power efficiency, which could approach the 'Carnot-cycle', a Stirling cycle should be implemented in a way, which could approximate the ideal type of the Stirling cycle.

However, those types of Stirling motors, which are applied at present, are not suitable for carrying out a nearly ideal Stirling cycle, because the regenerative heat-recuperation is not carried out at a constant volume, due to the motion of a power -piston. The motor in spite of this fact - owing to the regenerative heat recuperation - has a relatively good power efficiency, but only a heated expansion and a cooled compression are realized during the running of the motor, without an isochor (constant volume) heat exchange, as the power piston is in a continuous motion, except for the top and the bottom dead point positions, and therefore the volume of the gas - being in the work-cylinder - is continuously changing, as well. The power stroke and the compression stroke are directly shifting over into one another, which means that constant volume sections are not existing, at all. Consequently, the expansion work is significantly less, and the compression work is considerably more, as compared to the ideal Stirling cycle. Because of the lack of the constant volume sections, the amount of work, which could be utilized within one turn, will significantly lag behind the possible maximum amount. Those thermal cycles, which are implemented in the practice, would even not approximately resemble the ideal Stirling cycle. In spite of this fact, this solution is considered as the best thermal power efficiency caloric engine, up to now. As it is well seen on the diagram of the thermal cycle (shown with continuous line) the gas is heated in the expansion stroke, is cooled in the compression stroke and no other step is carried out. However, this is only a double-stage thermal cycle, which is not identical with the ideal Stirling cycle, which contains four different stages.

Therefor, the object of the present invention is to provide a method and apparatus for implementing caloric cycles in a way which approximate the ideal thermodynamic cycles.

In the process according to the invention, volume capacities of working spaces are changed; expandable working medium is flowing between the working spaces, and heat-transfer and / or heat-removal is carried out; wherein the volume capacities of the co-operating working spaces are changed in about a 180 degree counter-stroke, the working medium is driven from a decreasing volume capacity working space into an increasing volume capacity working space, in an order, which complies with the different stages of the thermodynamic cycle, and every stage of the thermodynamic cycle is realized separately, in a way, that always the same stage of the cycle should take place between two working spaces.

Preferably, the working medium is divided by valves into at least two identical parts. In case of an open thermal cycle, one portion of the remaining heat of the working medium - which medium is just leaving the heat-engine thermal cycle -, will be used for the heating of the working medium of the thermal cycle; while on the other hand, that heat-quantity, which would be needed for the functioning of the procedure, will be provided by the thermal energy, which is produced by the burning of the fuel added to the working medium, in any of the working spaces. The working medium of the heat engine - which operates the heat-pump - will be cooled using the working medium escaping from the heat-pump thermal cycle, and which has a temperature lower than the ambient temperature. During the process, the valves separate the working spaces in such an order, that the working medium shall always flow in an identical direction between the working spaces.

One part of the working medium divided into two parts with the valves will realize the opposite stages of the thermal cycle, as compared to the other part of the working medium.

Each section of the thermal cycle will be realized separately, in such a way, that always the same stages of the thermal cycle will be carried out between the two working spaces.

One part of the working medium (where both parts have the same material quantity) will be heated, while the other part will be cooled, or the two parts are carrying out heat exchange between one another.

In an advantageous embodiment, the state of condition of the working medium changes during the realization of the different stages of the thermal cycle.

In case of a combined embodiment, the apparatus primarily used for heating purposes consists of two parts: one part is a caloric cycle heat engine, and the other part is a caloric cycle heat pump. The apparatus is connected to the environment by at least three means for heat-exchange, wherein the heating of the working medium of the heat-engine is carried out through a heat-exchanger, which is at the highest temperature; the working medium of the heat-pump is removing heat from the environment through the heat-exchanger of the lowest temperature; and the heat-engine and the heat-pump output heat through the heat-exchanger working at a temperature between the first two temperatures.

The invention is based on the recognition that the thermal cycle has to be divided into different stages because the individual stages of the caloric cycle may not be realized in the same working space, one after the other, in a way, which approximates the ideal cycle. These individual stages have to be realized stage- by-stage, between those sorts of working spaces, which can be separated from each other. In this special case, the feature of the thermal cycle will depend upon the connection order of those stages, which separately can be realized in such a way, which approximates the ideal thermal cycle. This recognition - considering its relevance - is much more like a process, than an apparatus. However, special types of apparatuses are needed, for being able to realize the process. Hereinafter, we are giving the details of the process, in connection with the description of the operation of the apparatuses.

The realization of the thermal cycle stages is practically depending upon two things, from thermodynamic aspects. The first is changing of the volume of the working medium and the second is changing of the temperature of the working medium. The invention provides a very simple solution for changing the volume capacity of the working medium, in a pre-definable way. The changing of the temperature of the working medium is only interesting from the procedural aspects. But from structural aspects, this can be realized by many known means.

According to one possible embodiment, changing of the volume of the expandable working medium can be realized with the help of two pistons being in about 180 degrees shifted position, and consequently moving in counter- directions. In this way, the consecutive work-cylinders will be connected - by the control-valves - to the following work-cylinder which is just in front of them in the sense of the operating direction of the thermal cycle, when they suck in the working medium. These consecutive work-cylinders will be connected to the following work-cylinder which is just after them in the operation order direction, when they push out the working medium. In this way the expandable working medium will always flow into the working cylinder which is just after it in the operation order direction. Therefore the change of the volume of the working medium will always depend upon the volume capacity of the consecutive working cylinder. For the purpose of being able to understand the given instances better and more easily, the possible structural design of the apparatus and also the operational principle of the process will be explained by the technical solution, wherein pistons are moving into opposite directions.

Another possible way of realizing the volume-change according to the invention is, that the pistons are moving into the same direction, within the same phase. In this case, when the decreasing volume working space is above a piston, then the increasing volume working space has to be under the same piston, or vice versa, if the decreasing volume working space is under the piston, then the increasing volume working space has to be above it. Even in this case, the important thing is that during the transport of the working medium, the volume capacity of the two co-operating working spaces has to change into the opposite direction, that is: when one of the spaces is decreasing, at the same time, the other space has to be increasing.

The method with pistons moving into opposite directions, and also with pistons moving into the same direction, may be freely combined with each other. When combining these two methods, further advantageous structural designs may be created without changing the essential idea of the invention; however, the description would be much complicated and less understandable. Therefore, the embodiments with the pistons moving into the same direction will only be illustrated by the first, simplified Example. We do think that describing the combinations of the two basic cases would be superfluous and unnecessary.

In an apparatus according to the invention, mechanical constraint forces will determine the actual volume of the working medium, which flows among the cooperating working cylinders, which cylinders are functioning alternatively by every half-turn, with the working cylinder just prior to the cylinder, and just after the cylinder in the order. The reason is that the pistons are moved by a joint crank shaft. The valve control will determine the flow direction of the working medium, and this way it may be ensured, that the working medium flows from the decreasing volume capacity working cylinder towards the increasing volume capacity working cylinder, which is just successive in line. The volume-change of the working medium can be effectuated mechanically, while the temperature-change of the working medium can be influenced by the wall of the working cylinders, or more by preferably by heat-transfer or heat- removal through heat-exchangers. A closed thermal cycle may be provided if the last working cylinder is connected to the first working cylinder. If the first working cylinder sucks the working medium from the ambient volumes, and if the last working cylinder pushes the working medium out into the ambient volumes, then an open thermal cycle may be obtained. In this latter case, the heat-exchanger for the heating and cooling of the heat-engine is left out, because the heat needed for the operation will be provided by the chemical reaction between the fuel and the sucked-in air; while the heat will leave together with the exhausted working medium. In the present description, detailed illustration of this type of internal combustion heat-engines, these embodiments will only be shown schematically, because the structure thereof is essentially identical with that of the apparatuses implementing closed thermodynamic cycles. An important difference is, however, that the final working spaces are not connected to the first ones, but to the environment.

In the case of a closed cycle, the apparatus according to the invention contains variable volume capacity working spaces and valves between the working spaces. The elements changing the volume capacities of the working spaces are interconnected with each other, the individual working spaces are connected in series, and the last working space is connected to the first one.

In case of open thermal cycles, the apparatus contains variable volume capacity working spaces and valves between the working spaces, wherein the elements changing the volume capacities of the working spaces are in forced connection with each other. The individual working spaces are connected in series and the apparatus includes at least two working spaces, which are connected to the ambient atmosphere.

The greatest advantage of the invention is that any caloric cycle divided into stages can be implemented in a way, which approximates the ideal thermal cycle.

This would result in a considerable improvement of the efficiency / performance.

This solution may be used widely in the field of caloric engines, primarily with heat engines and also with different types of heat pumps in all fields of the technical life.

Further details of the invention will be described by way of examples, with the help of the attached drawing. In the drawing:

Figure 1 : shows the P-V Diagram both of the ideal and the practical Stirling thermal cycle,

Figure 2: is a schematic arrangement of a traditional, alpha-type Stirling motor,

Figure 3: is a schematic arrangement of an apparatus for the realization of the Carnot-type thermal cycle, which contains a minimum number of structural elements,

Figure 4: is a schematic arrangement of a Stirling-type heat engine according to the invention,

Figure 5: is a schematic arrangement of a heat engine similar to the Stirling-type thermal cycle heat engine, where the working medium changes its state of condition,

Figure 6: is a schematic arrangement of a Stirling-type heat engine; where the regenerative heat recuperation is carried out using a heat pump,

Figure 7: is a schematic arrangement of a heat pump, which may be used for improving the regenerative heat recuperation, and

Figure 8: is a schematic arrangement of a heat engine, which is suitable for the realization of the Carnot-type thermal cycle.

Figure 2 shows a schematic arrangement of a traditional Stirling-type motor. The Stirling heat engine cycle is carried out in the alpha-type Stirling motor between two co-operating working cylinders. The pistons of the co-operating working cylinders are arranged in 90 degrees, relatively to each other. The motor - during each of its rotations - will realize the Stirling-type heat engine cycle within the same working space, during four successive stages, which cannot be separated from each other.

During the first phase, when both pistons are moving downwards, the expansion of the working medium is carried out. Following this - during the second phase - one of the pistons changes its movement direction, and starts to move upwards, consequently, it will push the working medium into the direction of the cooled working cylinder, through the regenerator. In the meantime - because of the opposite direction movement of the pistons - the volume will not change considerably. During the third phase the other piston will change its movement direction to the opposite, and then both pistons will move upwards, therefore the working medium will be compressed. In the fourth phase one of the pistons will also change its movement direction into the opposite, and will push back the working medium into the heated working cylinder, through the regenerator. Because of the opposite direction movement of the pistons, the volume will not change considerably.

During the operation, the pistons will move back and forth the working medium, between the two co-operating working cylinders. Because of the continuous movement of the pistons, there are no constant volume stages at all, therefore the work, which may be gained during one rotation, will considerably be behind the possible maximum amount of work. Therefore the real heat-cycle will not resemble the ideal Stirling heat cycle. As it can be seen from the P-V diagram (shown in Figure 1 ), basically everything what happens is, that the gas is heated in the expansion stroke, while it is cooled in the compression stroke. Therefore this is essentially only a double-stage heat cycle, which is not identical to the four- stage ideal Stirling heat cycle.

A further well-known approach is shown in WO 2007/019815. In this solution - similarly to this invention - the Stirling heat cycle is carried out between double- operated working cylinders, which have different volume capacities. This apparatus realizes four Stirling heat cycles at the same time, within each rotation of the crank-shaft, helping each other's operations. The idea of that invention is primarily based upon the operation of the valve, which short-circuits the heat cycle, placed between the working spaces of the co-operating two cycles; however, none of the four co-operating Stirling cycles is broken down into different stages, which could be separately realized. The co-operating working spaces are not separated by valves, and also the different working spaces do not interconnect to each other alternately. The pistons of the co-operating working spaces are arranged in 90 degrees in relation to each other; while the working medium flows back and forth between the working spaces. In order to realize the regenerative heat recuperation, a conventional specific heat regenerator is applied. In this way, the apparatus is not suitable for the realization of a thermal cycle, which approximate the ideal cycle.

In the process according to this invention not the conventional method is applied, wherein different thermodynamic cycles are realized successively, one after the other in the same variable volume capacity working space. According to this invention, the thermodynamic cycle has to be realized in different stages, and the individual stages are connected to each other ensuring that these stages could operate one another, and finally, the last stage should be connected into the first stage. In the following the realization of the individual stages according to the invention are described. From these stages different thermodynamic cycles can be combined, depending on the succession of the individual stages.

When Heated Expansion is realized, the working medium is pushed into the space above the piston of the larger volume capacity working cylinder which piston moves downwards, by the upwards moving piston of a smaller volume capacity working cylinder, by a heated heat-exchanger. The heated polytropic expansion can be modified to become an isothermal or even an isobar feature expansion, depending upon the degree of the heat-transfer. The heated expansion may be deemed as isothermal, if the amount of the heat transferred into the expanding working medium is enough to keep the temperature of the working medium nearly constant, during the expansion. During the heated expansion process, the pistons, which can alter the volume capacities of the working spaces, are in interlocked connection with each other, and are moving in the opposite direction push-pull motion.

When Cooled Expansion, is realized, the working medium is pushed into the space above the piston of a smaller volume capacity working cylinder (which piston moves downwards), by the upwards moving piston of a larger volume capacity working cylinder, by a cooled heat-exchanger. The heated polytropic compression can be modified to become an isothermal or even an isobar feature compression, depending upon the degree of the heat-removal. The cooled compression may be deemed as isothermal, if the amount of the heat removed from the compressing working medium is enough to keep the temperature of the working medium nearly constant, during the compression. During the cooled compression process, the pistons, which can alter the volume capacities of the working spaces, are in interlocked connection with each other, and are moving in the opposite direction push-pull motion.

When lsochor Heat-Transfer or Heat-Removal is realized, the working medium is pushed into the space above the piston of an identical volume capacity working cylinder (which piston moves downwards), by the upwards moving piston of an identical volume capacity working cylinder, by the heated or the cooled heat- exchanger. If we do not consider the differences between the volume capacities of the heat-exchangers, and the movement speed of the pistons, and the greatest volume capacities of the two working cylinders are identical to each other, then the process may be deemed as isochor, or at least we consider them to be isochor. During the realization of the constant volume heat-removal or heat- transfer the pistons, which alter the volume capacities of the working cylinders, are in interlocked connection with each other, and are moving in the opposite direction (push-pull motion).

When Adiabatic Expansion is realized, the working medium is pushed into the space above the piston of the larger volume capacity working cylinder (which piston moves downwards), by the upwards moving piston of the smaller volume capacity working cylinder. During the realization of the expansion process, which may be considered as adiabatic, the pistons, which alter the volume capacities of the working cylinders, are in interlocked connection with each other, and are moving in the opposite direction (push-pull motion).

There are already known approaches for the realization of the expansion processes, which may be deemed as adiabatic. In the case of those piston reciprocating steam engines, which have a multiple-type expansion process, the technical solution - regarding its fundamentals - is identical to the case of the adiabatic expansion process, involved in this Invention. However, in these steam engines, this approach was exclusively applied with the purpose of being able to realize the adiabatic expansion, for realizing only one stage of the complete heat engine thermal cycle.

In case if Adiabatic Compression is realized, the working medium is pushed into the space above the piston of the smaller volume capacity working cylinder (which piston moves downwards), by the upwards moving piston of the larger volume capacity working cylinder. During the realization of the compression process, the pistons, which alter the volume capacities of the working spaces, are in interlocked connection with each other, and are moving in the opposite direction (push-pull motion).

The working medium in the above variants was always transferred from a decreasing volume capacity working space, towards an increasing volume capacity working space. When the piston changes the direction of its movement, then the working space, which had been increasing until then, would change for a decreasing volume capacity working space; and vice versa: the working space, which had been decreasing until then, would change for an increasing volume capacity working space. In order to realize a thermal cycle, the working spaces have to be separated from each other using valves, and the movement of those structural elements, which change the volume capacities of the working spaces, have to be operated in an interlocked connection. In case the control valves - which are used for managing the working medium - are opened or closed at the same time, simultaneously with the direction-change of the piston, then it is possible to connect one working space sometimes with the preceding working space, and also sometimes with the succeeding working space. However, if the structural elements - which change the volume capacities of the working spaces - are in interlocked connection with each other, then the structural elements can only move together; and therefore these elements will move into the direction, where the total force acting on them is greater. The control of the valves has to be defined in such a way, that the working medium should always flow into the same direction, into the succeeding working space in the order. In this way, in an apparatus for the realization of a complete thermo-dynamic cycle, the structural elements that consist of two co-operating working spaces and are dimensioned and designed for the realization of the individual thermodynamic stages in a way, which approximates the ideal cycle, may alternately be connected to one another, or to the working spaces, which are designed and dimensioned for the preceding or for the succeeding thermodynamic cycle. If the last working space is connected to the first one, the working medium may be made flow around in the apparatus, along a direction, which is determined by the open or by the closed status of the control valves. It means that the changing of the volume of the working medium will be determined by the volume capacity of the working space, which is the succeeding space in the line, according to the direction of the flow. In case the temperature of the succeeding working space is different from the temperature of the preceding working space, and the temperature of the working space is changing because of this fact, or such structural components are built into - between - the valves which separate the working spaces, which are suitable for changing the temperature of the working medium, and heat is transferred to or removed from the working medium through these structural elements, then a complete thermodynamic cycle is achieved.

This Invention is also suitable for realizing in stages thermal cycles of open-cycle internal-combustion heat engines. In this case the heat-transfer is also carried out during the realization of the heated expansion stage, but with the difference, that the heat quantity which is needed for the heating up of the expansion is provided by the heat quantity evolving during the chemical reaction, instead of the heat- transfer through the heat-exchanger.

The invention may primarily be used for operation of heat engines or heat pumps. In the following Examples the invention is illustrated by realization of different thermodynamic cycles in a way near to the ideal. The technical solutions essentially contain the same perception; however, from procedural aspect, the realized heat-cycles may be basically different, depending upon the fact, in what sort of order the individual stages of the thermodynamic cycles to be realized are succeeding one another. These may even significantly differ from each other, in the sense, that what amount of heat energy is transferred to or removed from one or the other working medium, during the realization of the individual thermal cycle stages.

In Figure 3, a very simplified example is shown, where only the most necessary structural elements are included: this example is only capable for a sort of alternating movement. Heat-exchanger between the first and the second working cylinders, for heating up the working medium has not been applied intentionally. Furthermore, the heat-exchanger for cooling of the working medium between the third and the fourth working cylinders is also omitted. The heating of one part of the working medium is carried out with heating the wall of the second working cylinder, while the cooling of the other part of the working medium is carried out with cooling the wall of the fourth working cylinder. The reference numbers are the same as applied in Figure 8.

This intentionally simplified apparatus is not considered as an advantageous instance. In this case the only purpose is to explain the operational principle of this invention.

This apparatus includes four different diameter-size working cylinders. There are pistons, fixed upon the piston-rod, in the working cylinders. The piston-rods are connected to the joint connection element. Each cylinder-head is equipped with suction and a compression valve. The working spaces, enclosed by the cylinder, the cylinder-head and the pistons, are connected to the preceding or to the succeeding working spaces, depending upon the closed or the open status of the valves, through the connection pipelines and also through the valves. The valve- changes are done at the bottom and at the top dead-point positions.

During the operation, the valves are dividing the working medium (in the working spaces) into two identical parts, which contain the same material volume. The pressure of these parts can be different, and may vary continuously. One part is expanding, and in the meantime its pressure is continuously decreasing, while at the same time the other part is compressed, and in the meantime its pressure is continuously increasing. The working medium parts are always located in a working space above the piston, and also in a working space under the piston. Consequently, the decreasing pressure of the one part will exert an opposite direction force at the same time, always towards two different diameter-size pistons. In the meantime, the increasing pressure of the other part will also exert an opposite direction force at the same time, always towards the other two different diameter-size pistons. As the pistons are in fixed connection with one another by the drive, they can only move together, and into the same direction. The direction of the movement of all those pistons which are in an interlocked connection with each other, will depend on the situation, whether which of the forces exerted by the four pistons is greater than the other : the continuously changing pressures exert force onto two pistons from above, and onto two pistons, from below. The degree of the force, which exerts its influence on the individual pistons will depend upon the actual pressure of the working medium and also upon the surface area of the pistons.

In the apparatus the working medium - which contains two identical volume of the material substance - is working in counter-stroke. Once one of the stroke is just expanding, at the same time the other stroke is just compressing and vice versa. As the working mediums are flowing into the succeeding working space of the apparatus just one after the other, therefore it is possible to remove heat from one part of the working medium, while at the same time we can transfer heat to the other part of the working medium. Consequently, the pressure of the working medium is changed by two factors, at the same time. One factor is the changing of the volume capacity of the working spaces, while the other factor is the changing of the temperature of the working medium, by heat-transfer, or by heat- removal. The changing of the volume of the working medium which is divided into two parts is fixed with mechanical constraints, as the changing of the volume capacities of the working spaces are carried out always the same way: while one part of the working medium is under compression, at the same time the other part of the working medium is necessarily under expansion. If we cool down that part of the working medium, which is under compression, then the pressure will increase only very slowly, therefore the process of compression will require less mechanical work to be invested. If we transfer heat to that part of the working medium, which is under expansion, then the pressure will decrease more slowly, therefore the expansion will produce larger amount of mechanical work. The difference between that pressure which is increased by the heat-transfer and that pressure, which is decreased by the heat-removal, will move the pistons.

The structural elements of the apparatuses are arranged as follows. The first 5 working space 72 and the second working space 95 are connected to each other by pressure-valve 82 of the top cylinder-head 80 of the first working cylinder 76, by connecting lines, and by suction-valve 98 of the bottom cylinder-head 97 of the second working cylinder 77. The second working space 95 and the third working space 74 are connected to each other by pressure-valve 99 of the bottom io cylinder-head 97 of the second working cylinder 77, by connecting line, and by suction-valve 88 of the top cylinder-head 87 of the third working cylinder 78. The third working space 74 and the fourth working space 96 are connected to each other by pressure-valve 89 of the top cylinder-head 87 of the third working cylinder 78, by connecting line, and by suction-valve 101 of the bottom cylinder-

15 head 100 of the fourth working cylinder 79. The fourth working space 96 and the first working space 72 are connected to each other by pressure-valve 102 of the bottom cylinder-head 100 of the fourth working cylinder 79, by connecting line, and by suction-valve 81 of the top cylinder-head 80 of the first working cylinder 76.

20 The working medium in the second working space 95 is heated by the heating of the wall of the second working cylinder 77. The working medium in the fourth working space 96 is cooled by the cooling of the wall of the fourth working cylinder 79.

The pistons 68, 69, 70, 71 are moving upwards from the bottom dead point

25 position. One part of the working medium is flowing through the open pressure valve 82 of the first working cylinder 76 and the open suction valve 98 of the second working cylinder 77, from the first working space 72 into the second working space 95, while it is expanding. The pressure of the working medium is exerting force onto the first piston 68 from the top, while onto the second piston

30 69 from below. The piston 68 of the first working cylinder 76 has a smaller diameter than piston 69 of the second working cylinder 77. Consequently, the identical pressure will exert greater force into upwards direction, because of the larger surface of the second piston 69. The second working cylinder 77 is continuously heated, therefore the temperature of the medium which flows towards this cylinder, is increasing. This increase of the temperature is trying to balance the pressure decrease which occurs because of the expansion. (This 5 expansion may even be of isobaric feature, depending upon the degree of the heat-transfer.)

At the same time, the other part of the working medium is flowing through the open pressure valve 89 of the third working cylinder 78 and also through the open suction valve 101 of the fourth working cylinder 79, from the third working space

10 74 into the fourth working space 96, while it is compressed. The pressure of the working medium is exerting force onto the third piston 70 from the top, while onto the fourth piston 71 from below. The piston 70 of the third working cylinder 78 has a greater diameter than piston 71 of the fourth working cylinder 79. Consequently, the identical pressure will exert greater force into downwards direction, because

15 of the larger surface of the third piston 70. The fourth working cylinder 79 is continuously cooled, therefore the temperature of the medium which is compressed towards this cylinder, is decreasing. This decrease of the temperature is trying to balance the pressure increase which occurs because of the compression. (This compression may even be of isobaric feature, depending

20 upon the degree of the heat-removal.)

Accordingly, one part of the working medium exerts a greater shifting force downwards, while the other part of the working medium exerts a greater force upwards onto the joint moving component 104, through the piston-rods 103 and the four pistons 68, 69, 70, 71. Those forces, which are counteracting against 25 each other, will partly extinguish each other. This means, that the direction of the displacement will depend upon, which is the greater force, among those two counteracting forces, which act onto the four pistons 68, 69, 70, 71.

After the pistons had reached the top dead point position, the valves are switching over, and the working spaces will be connected to another working 30 space. Then the pistons 68, 69, 70, 71 are moving from the top dead point position towards the bottom dead point position. One part of the working medium is flowing through the open pressure valve 99 of the second working cylinder 77 and the open suction valve 88 of the third working cylinder 78, from the second working space 95 into the third working space 74, while it is adiabatically expanding. The pressure of the working medium is exerting force onto the second piston 69 from below, while onto the third piston 70 from above. The piston 69 of the second working cylinder 77 has a smaller diameter than piston 70 of the third working cylinder 78. Consequently, the identical pressure will exert greater force downwards, because of the larger surface of the third piston 70.

At the same time, the other part of the working medium is flowing through the open pressure valve 102 of the fourth working cylinder 79 and the open suction valve 81 of the first working cylinder 76, from the fourth working space 96 into the first working space 72, while it is adiabatically compressed. The pressure of the working medium is exerting force onto the fourth piston 71 from below, while onto the first piston 68 from above. The piston 71 of the fourth working cylinder 79 has a greater diameter than piston 68 of the first working cylinder 76. Consequently, the identical pressure will exert greater force into upwards direction, because of the larger surface of the fourth piston 71.

In this case again, one part of the working medium exerts a greater force downwards, while the other part of the working medium exerts a greater force upwards onto a common drive 104, through piston-rods 103 and also through the four pistons 68, 69, 70, 71. Those forces counteracting against each other will partly extinguish each other in this case, as well. This means, that the direction of the displacement will depend upon the fact, whether which the greater force is, among those two counteracting forces, which act onto the four pistons 68, 69, 70, 71.

By this time, the working medium, which contains identical material quantities, and, which are separated from each other with valves, will reach back into its starting point. This entire process may be repeated. The operability of the apparatus will depend upon the quantity of the transferred or the removed heat. The pressure-and-tension spring 105 serves for drawing the pistons 68, 69, 70, 71 back into their starting position.

In the following example (Figure 4) a Stirling heat engine thermodynamic cycle is shown, wherein the actual apparatus realizes a thermodynamic cycle - combined according to the invention from separate stages of the cycle. The real specialty of the operation of the Stirling heat engines, according to the invention is that the peak-pressure will be evolving during a regenerative heat recovery process, as a result of the heat exchange of the working medium, which contains two identical quantities of material substances.

For providing an apparatus (shown in Figure 4), which operates according to the Stirling-type heat cycle, in the simplest case it is necessary to provide two working cylinders, which have different volume capacities, and which also make possible the double-operation, together with their pertaining pistons, crank mechanisms, heat-exchangers, and also with cylinder-heads from both ends of the double-operated working cylinders, with positively-controlled inlet- and delivery-side valves, with control-gear shafts, with pressure-controlled valves, with bearings, with motor-blocks, which serve for the placement/arrangement of the structural elements, etc. In the Figures one can see double-operated working cylinders, where in case of designs according to these Figures the cylinder-head which is situated closer to the lever-shaft is called as 'upper', and the one which is farther, is called as 'lower' cylinder-head. In these design examples we showed the apparatus with positively-controlled valves, however, some of these valves may also be replaced with pressure-controlled valves, as well. These denominations regarding the spaces just in front of and behind the piston should always understood according to the actual movement direction of the piston. The volume capacity of the working cylinder is deemed as working space. The working medium - which is divided into two equal parts by the valves - is continuously flowing into the same direction. The different stages of the cycle are carried out in a separated way from each other, however, each stage is carried out always at the same place, during the co-operation of the same two working cylinders. We will use the expressions applied for the denominations of the ideal cases, when we will explain the individual stages of the thermodynamic cycle, however, in the reality, these ideal cases may not be realized. At the same time, saying this, we also refer to the goal: what sort of thermodynamic stage we would like to realize. For instance: in each of the examples we are mentioning isotherm expansion or compression, because this is the most economic case, however, in the reality we know, that the isotherm expansion may not be realized perfectly. However, if we - during the expansion - transfer such an amount of heat to the expanding gas, which would balance the cooling down, occurring because of the expansion of the gas, then the expansion may be deemed as isothermic; or in the other case - during the compression - we remove such an amount of heat from the gas, which would balance the warming up of the gas, occurring because of the compression of the gas, then the compression may be deemed as isothermic. If we follow the same logic, we can deem as 'isochor¹ that case, when the working cylinder - which carries out the pushing out of the working medium - will push the working medium through the heat-exchanger into a working cylinder, which has the same volume capacity as the pushing-out working cylinder.

As Figure 4 shows: the piston 11 of the smaller working cylinder 1 is connected to the lever shaft 27 by the piston-rod 21 - which belongs to the smaller working cylinder 1 - then also by the driving rod 23 and by the crank 25, then through this crank it is in interlocked coupling with the greater piston 12 which moves in the larger working cylinder 2, which in turn is also connected to the lever shaft 27 by the piston-rod 22 - which belongs to the greater piston 12, and also by the driving rod 24 and by the crank 26. The movement of the smaller piston 11 and that of the greater piston 12 will change the volume capacities of the first 13, the second 14, the third 15 and the fourth 16 working spaces. The first working space 13 is connected to the second working space 14 by the pressure-valve 4 which is located on the upper cylinder head 17 of the smaller working cylinder 1 , then also by the heated heat-exchanger 28, and by the suction-valve 8 which is located on the upper cylinder head 18 of the greater working cylinder 2. The second working space 14 is connected to the third working space 15 by the pressure-valve 7 which is located on the upper cylinder head 18 of the greater working cylinder 2, then also by the heat-output line 30 of the regenerative heat-exchanger 29, and also by the heat-exchanger which serves for the additional heat-removal 34, as well as by the suction-valve 9 which is located on the lower cylinder head 20 of the greater working cylinder 2. The third working space 15 is connected to the fourth working space 16 by the pressure-valve 10 which is located on the lower cylinder head 20 of the greater working cylinder 2, then also by the cooled heat- exchanger 32, and by the inlet suction-valve 5 which is located on the lower cylinder head 19 of the smaller working cylinder 1. The fourth working space 16 is connected to the first working space 13 by the pressure-valve 6 which is located on the lower cylinder head 19 of the smaller working cylinder 1 , then also by the pressure-controlled valve 35, and by the line 31 of the regenerative heat- exchanger 29, which line serves for the heat-transfer , then by the heat- exchanger 33, which serves for the additional heat-transfer , and by the suction- valve 3 which is located on the upper cylinder head 17 of the smaller working cylinder 1. The movement of the positively-controlled valves is determined by the status of the control gear, which is driven by the lever shaft 27, - however, this is not shown in the drawing. The changings of the valves are carried out when the bottom and the top dead point positions are reached by the pistons 11 , 12.

The above heat engine operates as follows. The smaller 11 and the greater 12 pistons are in interlocked connection with each other, by the crank mechanisms, which are wedged in 180°, on the lever shaft 27. Consequently, also the changing of the volume capacities of the working spaces 13, 14, 15, 16, which are changed by the pistons 11 , 12, are carried out in a defined way, relative to each other. The pistons 11 , 12, moved within the working cylinders 1 , 2, are in interlocked connection with each other, by the crankshaft 27, and also by the cranks 25, 26, by the driving rods 23, 24, by the piston-rods 21 , 22, and furthermore by the studs, which are connecting these rods.

Because of the interlocked connection of the pistons 11 , 12, the changing of the volume of the working medium - when the crankshaft 27 is turning - will be determined by the joint changing of the volume capacities of the fourth 16 and first 13 working spaces, connected by the valves 3, 6 - which are actually in an open position - and also by the joint changing of the volume capacities of the second 14 and third 15 working spaces, connected by the valves 7, 9; or determined by the joint changing of the volume capacities of the first 13 and second 14 working spaces, connected by the valves 4, 8 - which are actually in an open position just after the changing of the valves - and also by the joint changing of the volume capacities of the third 15 and fourth 16 working spaces, connected by the valves 5, 10. Where the volume capacities of the working spaces, connected by the open-position valves are equal, there the volume may be practically deemed as unchanged. Where the volume capacities of the working spaces, connected by the open-position valves are different, there the volume will decrease, or increase, if the crankshaft 27 is turning. The pressure between the working spaces, which are connected together by the valves, is trying to get balanced. In case we do not take into consideration the pressure- drop, which occurs because of the flow-losses - if the crank throw is identical - then it will be depending upon the difference between the surfaces of the pistons and also upon the direction of the line of influence of the forces, whether the force, which exerts its effect onto the pistons - which are changing the volume capacities of the working spaces connected by the open-position valves - will exert its influence onto the crankshaft 27 with greater power, into the direction of turning forward, or into the direction of turning backward. The pressure of the working medium which flows among the co-operating working spaces will be depending upon the changing of the volume capacity of the working medium, and/or upon the changing of the temperature of the working medium. The change of the pressure of the working medium will be influenced by changing the temperature of the working medium, which flows through the heat-exchanger placed between the valves of the co-operating working cylinders. In the Operation Description we always denominate only the open-position valves, because the other valve located at the same cylinder-head will be naturally in its closed position, at the same time. In our apparatus, at the same time, we always make flow at least two material quantities, which contain the same amount of material medium, in a successive method: these quantities are always following each other. The amount of heat which is necessary for the operation of our apparatus is entered into the system through the heated heat-exchanger, during the process of the expansion; or: the heat-removal, which is also necessary for the operation of the apparatus, is ensured to occur during the compression stroke, the cooled heat-exchanger. During the first half turn of the operation in one half of the working medium divided into two equal parts the heated expansion stage is realized between the first working space 13 and the second working space 14, while in the other half of the working medium the cooled compression stage is realized between the third working space 15 and the fourth working space 16. Piston 11 of the smaller working cylinder 1 is moving from the lower dead point position towards the upper dead point position, while piston 12 of the greater working cylinder 2 is moving from the upper dead point position towards the lower dead point position. Piston 11 of the smaller working cylinder 1 is moving from the decreasing volume capacity first working space 13 into the increasing volume capacity second working space 14, into the greater working cylinder 2, by the open delivery valve 4 of the upper cylinder head 17 of the smaller working cylinder 1 , and also by the heated heat-exchanger 28, as well as by the open suction valve 8 of the upper cylinder head 18 of the greater working cylinder 2. The working medium, which is flowing into the second working space 14, from the first working space 13, through the heated heat-exchanger 28, while expanding, is taking up heat through the heated heat-exchanger 28, from an external heat-source. In that case, when the working gas - during the process of the expansion - is taking up such a quantity of heat through the heated heat-exchanger 28, that the temperature of the expanding working gas - during the process of the expansion

- could at least approximately remain at a constant level, then the expansion may be considered as isothermic. In the meantime, the piston 12 of the greater working cylinder 2, which is just moving downwards, will push out the working medium from under itself, from the decreasing volume capacity third working space 15, into the increasing volume capacity fourth working space 16, into the smaller working cylinder 1 , by the open delivery valve 10 of the lower cylinder head 20 of the greater working cylinder 2, and also by the cooled heat-exchanger 32, as well as by the open suction valve 5 of the lower cylinder head 19 of the smaller working cylinder 1. The working medium, which is flowing into the fourth working space 16, from the third working space 15, through the cooled heat- exchanger 32, while compressing, is giving heat away through the cooled heat- exchanger 32, into the ambient environment. In that case, when the working gas

- during the process of the compression - is giving away such a quantity of heat through the cooled heat-exchanger 32, that the temperature of the working gas being under compression - during the process of the compression - could at least approximately remain at a constant level, then the compression may be considered as isothermic.

Just after the lower dead point position has been reached, the valves are switching over, and the pistons are starting to move backwards.

During the second half-turn the isochore heat-rejection is realized in one half of the divided working medium between the second 14 and the third 15 working spaces, while in the other half of the working medium isochore heat-uptake is realized, at the same time, between the fourth 16 and the first 13 working spaces. These two stages serve for the regenerative heat recuperation, therefore the working medium, which is flowing through the two lines of the counterflow heat exchanger 29, where one line serves for the heat-rejection 30, and the other line serves for the heat-uptake 31 ; this way these lines of the working medium are heating or cooling each other. The piston 11 of the smaller working cylinder 1 is moving from the upper dead point position towards the lower dead point position, while the piston 12 of the greater working cylinder 2 is moving from the lower dead point position towards the upper dead point position. In the smaller working cylinder 1 the delivery valve 6 of the bottom cylinder head 19 and the suction valve 3 of the top cylinder head 17 are in open position. Therefore the downwards moving piston 11 of the smaller working cylinder 1 will push the working medium being ahead of it from the decreasing volume capacity fourth working space 16 into the increasing volume capacity first working space 13, behind itself, through the pressure-controlled valve 35, the heat uptake branch 31 of the regenerative heat-exchanger 29, and heat-exchanger 33, which serves for the supplementary absorption of heat. The volume of the working medium practically is not changing in the meantime, as the fourth 16 and first 13 working spaces are of equal volume capacities, and the two working spaces are changing with the same speed, but in opposite directions. The working medium will - in the meantime - take up heat in the counterflow regenerative heat exchanger 29, from the working medium, which moves in opposite direction, and therefore it is warming up, and its pressure is increasing. The pressure-controlled valve 35 will withhold the working medium from flowing back for a short time during the period of valve-shift, because of the higher pressure of the working medium which is captured within the branch 31 of the regenerative heat exchanger 29. An amount of heat missing due to the imperfectly realized regenerative heat-recovery can be feed into the working medium by the heat-exchanger 33 used for supplementary heat-input.. At the same time, the piston 12 of the greater working cylinder 2 is moving from the lower dead point position towards the upper dead point position. Therefore the upwards moving piston 12 of the greater working cylinder 2 will push the working medium from the decreasing volume capacity second working space 14 just behind itself, into the increasing volume capacity third working space 15 through the open delivery valve 7 of the upper cylinder head 18 of the greater working cylinder 2, and the heat-rejection line 30 of the regenerative heat-exchanger 29,, as well as through the heat-exchanger 34, for supplementary heat removal, and also through the open suction valve 9 of the lower cylinder head 20 of the greater working cylinder 2. The volume of the working medium practically is not changing in the meantime, as the second 14 and third 15 working spaces are of equal volume capacities, and the two working spaces are changing with the same speed, but in opposite directions. The pistons 11 , 12 of the smaller 1 and of the greater 2 working cylinders are pushing the working medium just over behind themselves, therefore the volume of the working medium remains unchanged, because the volume of the increasing volume capacity working space behind the piston will increase to such extent, as much the decreasing volume capacity working space in front of the piston will decrease. It means that practically the volume of the working medium does not change. On the other hand, the pressure of the working mediums will change, because of the change of the temperature of the working mediums, which are flowing through the counterflow regenerative heat-exchanger 29. The working medium - in the meantime - is giving off heat, through the counterflow regenerative heat-exchanger 29, therefore the working medium, which is flowing in the counterflow direction, will cool down, and its pressure is also decreasing. In the supplementary heat-removal heat-exchanger 34 the residual heat due to the imperfectly realized regenerative heat-recovery will be removed from the working medium. In this process, all stages of the Stirling heat engine will be realized, and the cycle may be repeated. If the pressure-controlled valve 35 is disconnected, and the shaft of the apparatus is rotated mechanically in a direction opposite to the direction of the heat engine cycle, then the working medium will flow in the apparatus in a reversed direction. In this case the heated heat-exchanger 28 will serve for the dissipation of heat to the atmosphere, while the cooled heat-exchanger 32 will serve for the removal of heat from the environment. In this case the apparatus may be operated as a heat pump, with investing mechanical work into it.

If applying the construction shown in Figure 5, the Stirling heat engine thermodynamic cycle may be realized in a way, wherein the working medium will condensate into liquid state in the compression stroke. The advantage of the process is, that even the thermal compression of the working medium is realized, due to the effect of the physical status change. Consequently, the mechanical work demand of the compression will decrease. Furthermore, the liquid-state working medium can be cooled easily, and the volume capacity of the condenser will not increase the detrimental area. The thermal cycle - in this case as well - is realized between two working mediums, which contain equal volumes of material quantities, during two half-turns of the crankshaft, that is the isothermal expansion is realized together with the isothermal and at the same time isobaric compression; plus in the second half-turn the isochore heat-dissipation serving for the regenerative heat-recovery is realized together with the heat-uptake, which cannot be considered as isochore any more, because of the operation of the energy-storage.

Even in this case, in the first stage of the thermal cycle, within the working stroke, a heated expansion is carried out. It is recommended during the heated expansion process, to add an amount of heat to the working medium, which would be needed for the realization of the preferably isothermal expansion.

In the second phase, an isochore heat-rejection is carried out, which would be needed for the realization of the regenerative heat recovery, as in the fourth stage.

During the third stage, the working medium will be cooled in a condenser from the superheated-steam status into a wet-steam, and then into a liquid state. In the fourth phase, regenerative heat recovery is carried out, when the liquid- state working medium is heated into a steam-gas state, using primarily the heat, which was given off in the second stage. It is recommended to make the thermal expansion of the liquid with applying an energy accumulator, which may be a simple spring compressed by the pressure of the expanding working medium. Later- during the succeeding working stroke - the stored force will be returned.

Then the cycle process is again repeated.

The apparatus shown in Figure 5 is nearly identical to the apparatus shown in Figure 4, therefore the same components are marked with the same reference numbers. In this apparatus, the piston 11 of the smaller working cylinder 1 is connected to the lever-shaft 27 through piston-rod 21 of the smaller working cylinder 1 driving-rod 23 and crank 25, and it is also in an interlocked connection with the greater piston 12, which is moving in the greater working cylinder 2, which again is connected to the crankshaft 27 through piston-rod 22 of the greater piston 12 driving-rod 24 and crank 26. The first working space 13 is connected to the second working space 14 through the delivery valve 4 located on the top cylinder head 17 of the smaller working cylinder 1 , by the heated heat- exchanger 28, and through the suction valve 8 located on the top cylinder head 18 of the greater working cylinder 2. The second working space 14 is connected to the third working space 15 through the delivery valve 7 located on the top cylinder head 18 of the greater working cylinder 2, then also by the line 30 - serving for the heat-rejection - of the regenerative heat-exchanger 29, and through the heat-exchanger 34 - serving for the supplementary heat-removal - and by the suction valve 9 located on the lower cylinder head 20 of the greater working cylinder 2. The third working space 15 is connected to the steam-space of the condenser 66, through the delivery valve 10 of the bottom cylinder head 20 of the greater working cylinder 2. The liquid space of the condenser 66 is connected to the fourth working space 16 through the suction valve 5 located on the bottom cylinder head 19 of the smaller working cylinder 1. The fourth working space 16 is connected to the first working space 13 through the delivery valve 6 located on the bottom cylinder head 19 of the smaller working cylinder 1 , through the pressure-controlled valve 35, then also by the line 31 - serving for the heat- uptake - of the regenerative heat-exchanger 29, and through the heat-exchanger 33 - serving for the supplementary heat-addition input - and by the suction valve 3 located on the upper cylinder head 17 of the smaller working cylinder 1. The spring-force operated energy storage facility 67 located on the upper cylinder 5 head of the smaller working cylinder 1 make it possible to change the volume capacity of the first working space 13 against the spring-force.

During the first half-turn of the operation of the heat engine for carrying out state change shown in Figure 5 working stroke and compression stroke are being carried out. The piston of the smaller working cylinder 1 is moving from the lower

10 dead point position towards the upper dead point position, and in the meantime the piston of the greater working cylinder 2 is moving from the upper dead point position towards the lower dead point position. The suction valve 5 of the lower cylinder head 19 of the smaller working cylinder 1 is open, therefore the piston 11 , which is moving in the upwards direction, will suck in a liquid-state working

15 medium from the condenser 66, into the fourth working space 16. At the very same time, the delivery valve 4 of the upper cylinder head 17 of the smaller working cylinder 1 is also in the open position, therefore the piston 11 which is moving into the upwards direction, will push out the working medium from the first working space 13, into the greater working cylinder 2, to the second working

20 space 14, through the heated heat-exchanger 28 and also through the open suction valve 8 located on the top cylinder head 18 of the greater working cylinder 2. During the working stroke - during the process of the expansion - we continuously add heat to the working medium which is expanding into the second working space 14 from the first working space 13, by the heated heat-exchanger

25 28. It is recommended to convert the process of the expansion with adding heat, into a sort of expansion, which may be considered as isothermal. For this purpose to reach, the temperature of the working medium has to be identical at least at the start and at the end of the expansion. In the meantime, the piston 12 moving downwards in the greater working cylinder 2 will push out from the third

30 working space 15 from under itself the medium - which is getting into its way - into the steam-space of the condenser 66, through the delivery valve 10 located on the lower cylinder head 20 of the greater working cylinder 2. The working medium is condensed to liquid state, because of the continuous cooling of the working medium being in the condenser 66. One advantage of condensing the working medium is that the pressure in the condenser 66 may be kept at an approximately constant value, depending upon the temperature of the working medium being in liquid state.

After the lower dead point position is reached, the valve is changing, and the pistons are starting to go back.

During the second half-turn of the operation of the heat engine, a regenerative heat recovery is being carried out. The piston 11 of the smaller working cylinder 1 is moving downwards from the upper dead point position, while in the meantime the piston 12 of the greater working cylinder 2 is moving upwards from the lower dead point position, towards the upper dead point position. Therefore the downwards moving piston 11 of the smaller working cylinder 1 will push the working medium from the fourth working space 16 into the first working space 13 behind the piston 11 that is: just over behind itself; through the pressure- controlled valve 35, and also through the heat-uptake line 31 of the regenerative heat-exchanger 29, as well as through the post-heating heat-exchanger 33, and through the suction valve 3 of the upper cylinder head 17. The liquid state working medium, which is pushed out from the fourth working space 16 , will change the state, into steam- or gaseous state, while it flows through the heat- uptake line 31 of the regenerative heat-exchanger 29, and flows also through the heat-exchanger 33, which serves for the supplementary heat-input. The spring- force operated energy accumulator 67 - located on the upper cylinder head 17 of the smaller working cylinder 1 - serves for the utilization of the heat expansion of the working medium. When the pressure of the working medium is increasing, because of the expansion due to the heat-input, then this pressure will move the piston of the energy accumulator 67, against the spring-force. Owing to this, the increase of the pressure can be kept within pre-defined limits. The regenerative heat-input in this case may no more be considered as isochore, however, the stored pressure-energy will be utilized by the next half-turn. The explanation is that due to the pressure decrease, which occurs during the working stroke, the spring will push the working medium energy storing means 67 - back to the first working space 13. From here it will further expand to the second working space 14. At the same time, piston 12 of the greater working cylinder 2 is moving from its lower dead point position to its upper dead point position. The upwards moving piston 12 from the second working space 14 will push out the working medium into the third working space 15, through the open delivery valve 7 of the upper cylinder head 18 of the greater working cylinder 2, and also through the heat- rejection line 30 of the regenerative heat exchanger 29 - and still further through the supplementary heat-removal heat-exchanger, and finally by the suction valve of the lower cylinder head of the greater working cylinder. During this, the working medium will carry out heat-exchange, with the other working medium flowing opposite in the other line of the regenerative heat-exchanger, which medium contains an equal quantity of material with the afore-mentioned working medium.

After this, the thermal cycle can be repeated.

The apparatus shown in Figure 6, is provided with heat pump for improving regenerative heat recovery.

One of the problems, hindering to obtain an ideal Stirling thermal cycle is the difficulty to realize a nearly ideal regenerative heat recovery. Taking into consideration that in the case of the Stirling-type caloric cycles the peak-pressure is evolving as a result of the regenerative heat recovery, the efficient realization of the regenerative heat recovery is of key-importance from the point of view of the operation of the apparatus. It is obvious, that the decrease of the temperature differences necessarily results in slowing down of the heat-exchange. To be able to solve this problem, in the following example a heat pump is used to increase the temperature difference using a heat pump, for the realization of an efficient regenerative heat-recovery.

In Figure 6, the connection of the structural elements is not the same as in Figure 4, primarily from that point of view, that here the regenerative heat-recovery is not realized through the heat-exchange between the lines 30 and 31 of the heat- exchanger serving for the realization of the regenerative heat-recovery, where line 30 would serve for giving off heat, and line 31 would serve for taking up heat, but this is done through a heat pump. It means, that the two lines of the regenerative heat-exchanger 29, do not directly carry out the heat-exchange between one another, but the line 30 - serving for giving off the heat - of the heat-exchanger 36, which is used jointly by the heat pump and the heat engine, will heat the working medium of the heat pump, while the line 31 - serving for taking up the heat - of the heat-exchanger 37, used jointly by the heat pump and the heat engine, will cool the working medium of the heat pump. Therefore, the description below, will mainly relate to the differences. The operation of the heat pump will be explained with reference to Figure 7.

During the first half-turn of the operation, the stage of the heated expansion will be realized in the heat engine, in a way, as it was already described in connection with Figure 3. In one half of the working medium divided into two equal parts, heated expansion is carried out between the first working space 13 and the second working space 14, while in the other half of the working medium, at the same time, the stage of the cooled expansion will be realized, between the third working space 15 and the fourth working space 16. Simultaneously, in the heat pump, which would serve for the improvement of the regenerative heat recovery, the pistons connected to the crankshaft 27 through cranks 62, 63, driving-rods 60, 61 , and piston-rods 64, 65, will compress or expand the divided working medium in the heat pump, too, as follows:

Within the greater working cylinder 40 of the heat pump, the upwards moving greater piston 42 will compress the working medium into the space above the downwards moving smaller piston 43, into the sixth working space 57, which has an increasing volume capacity, from the fifth working space 56, which has a decreasing volume capacity, through the open delivery valve 50 of the upper cylinder head 46 of the working cylinder 40 with larger volume capacity, and also through the open suction valve 49 of the upper cylinder head 47 of the smaller working cylinder 41. The temperature of the working medium, which is adiabatically compressed, increases. At the same time, within the smaller working cylinder 41 of the heat pump, the downwards moving smaller piston 43 will expand the working medium into the space below the upwards moving piston 42 of the greater working cylinder 40, into the eighth working space 59, which has an increasing volume capacity, from the seventh working space 58, which has a decreasing volume capacity, through the open delivery valve 54 of the lower cylinder head 45 of the smaller working cylinder 41 , and also through the open suction valve 53 of the lower cylinder head 44 of the greater working cylinder 40. The temperature of the working medium, which is adiabatically expanded, decreases.

During the other half turn of the heat engine, the working medium, which is flowing between the second 14 and the third 15 working spaces, gives off heat, as well as the working medium, which is flowing between the fourth 16 and the first 13 working spaces, takes up heat, or, other words, the regenerative heat recovery takes place. In the heat pump also heat giving-off and heat taking-up is being carried out, in the following way.

The upwards moving piston 12 of the greater working cylinder 2 of the heat engine will push the working medium into the third working space 15, through the open delivery valve 7, from the second working space 14, through the line 30 - serving for heat giving-off - of the heat-exchanger - which serves for heat uptake - of the heat pump 36, through the open suction valve 9. In the meantime, the downwards moving piston 42 of the greater working cylinder 40 of the heat pump will push the working medium into the fifth working space 56, through the open delivery valve 52 of the lower cylinder head 44 of the greater working cylinder 40 of the heat pump, from the eighth working space 59, through the line 38 - serving for heat uptake - of the heat-exchanger - which serves for heat uptake - of the heat pump 36, and through the open suction valve 51 of the upper cylinder head 46 of the greater working cylinder 40. The working medium of the heat engine is carrying out heat-exchange with the working medium of the heat pump, in the counter-flow heat-exchanger 36 of the heat pump, which serves for heat uptake, among such conditions, which may practically be considered as isochore circumstances.

At the same time the downwards moving piston 11 of the smaller working cylinder 1 of the heat engine will push the working medium into the first working space 13, through the open delivery valve 6, from the fourth working space 16, through the line 31 - serving for heat uptake - of the heat-exchanger 37 of the heat pump - which serves for heat giving-off -, through the open suction valve 3. In the meantime, the upwards moving piston 43 of the smaller working cylinder 41 of the heat pump will push the working medium into the seventh working space 58, through the open delivery valve 48 of the lower cylinder head 47 of the smaller working cylinder 41 of the heat pump, from the sixth working space 57, through the line 39 - serving for heat giving-off - of the heat-exchanger 37 of the heat pump - which serves for heat giving-off -, and through the open suction valve 55 of the lower cylinder head 45 of the smaller working cylinder 41. The working medium of the heat engine is carrying out heat-exchange with the working medium of the heat pump, in the counter-flow heat-exchanger 37 of the heat pump, which serves for heat giving-off, among such conditions, which may practically be considered as isochore circumstances.

As it can be seen from the above description, , the operation of the heat engine which realizes the Stirling heat engine thermodynamic cycle practically does not differ from that shown in Figure 4, in spite of the regenerative heat recovery through the heat pump. However, the efficiency of the regenerative heat recovery may be increased this way, and the Stirling cycle can be realized more perfectly. This apparatus may also be operated as a heat pump, if mechanical work is invested through the crankshaft 27 and the pressure-controlled valve 35is disconnected.

Furthermore, regenerative heat recovery assisted by heat pump can also be carried out in the apparatus shown in Figure 5.

Operation of the heat pump used for improving the regenerative heat recovery in the previous embodiment will be explained now with reference to Figure 7. The different stages of the heat-pump thermodynamic cycle are the following, supposing the ideal case: isentropic compression, isochore heat-loss, isentropic expansion, and isochore heat-absorption. The different stages of the thermodynamic cycle are realized separately, as explained above, using two cooperating working cylinder pairs. The working medium here is also divided into two equal parts. The flow-direction of the working medium is controlled between the working spaces with valves. In the following those valves will be mentioned only, which are open, while the piston is moving between the two dead point positions, as the other valve on the same cylinder head is obviously closed at that time. The connection of the structural elements practically is the same as in the previous examples.

The greater piston 42 of the greater volume capacity working cylinder 40 of the heat pump is connected to the crank lever shaft 27, through a crank mechanism, which consists of a driving rod 61 , a crank 63, and a piston-rod 64, which belongs to the greater working cylinder 40, while the smaller piston 43 of the smaller working cylinder 41 of the heat pump is connected to the crank shaft 27, through a crank mechanism, which consists of a driving rod 60, a crank 62, and a piston- rod 65, which belongs to the smaller working cylinder 41. The crank mechanisms, which belong to the smaller and to the greater volume capacity working cylinders 41 , 42, are wedged in 180° compared to each other. Pistons 42, 43 - because the crank mechanisms are fixed onto common crank-shaft 27 - are interlocked with each other.

The fifth 56, the sixth 57, the seventh 58 and the eighth 59 working spaces - having volume capacities changed by the interlocked pistons - are connected to or separated from each other by the control-valves. The delivery valve 48 of the upper cylinder head 47 of the smaller working cylinder 41 of the heat pump is connecting the sixth working space 57 of the heat-pump to the seventh working space 58, through the line 39 - which serves for giving off the heat - of the heat- exchanger 37 - which also serves for giving off the heat - of the heat-pump, and also though the suction valve 55 of the lower cylinder head 45 of the smaller working cylinder 41 of the heat pump. The delivery valve 54 of the lower cylinder head 45 of the smaller working cylinder 41 of the heat pump is connecting the seventh working space 58 of the heat-pump to the eighth working space 59, through the suction valve 53 of the lower cylinder head 44 of the smaller working cylinder 41 of the heat pump.

The delivery valve 52 of the lower cylinder head 44 of the greater working cylinder 40 of the heat pump is connecting the eighth working space 59 of the heat-pump to the fifth working space 56, through the line 38 - which serves for taking up the heat - of the heat-exchanger 36 of the heat-pump - which also serves for taking up the heat -, and also though the suction valve 51 of the upper cylinder head 46 of the greater working cylinder 40 of the heat pump. The delivery valve 50 of the upper cylinder head 46 of the greater working cylinder 40 of the heat pump is connecting the fifth working space 56 of the heat- pump to the sixth working space 57, through the suction valve 49 of the upper cylinder head 47 of the smaller working cylinder 41 of the heat pump.

The heat-pump cycle operation may be divided into four stages.

The first stage of the thermodynamic cycle is an isentropic compression, which is realized simultaneously with the third stage. The piston 43 of the smaller working cylinder 41 of the heat pump is moving downwards from the upper dead point position, while at the same time the piston 42 of the greater working cylinder 40 of the heat pump is moving upwards from the lower dead point position. The upwards moving piston 42 of the greater working cylinder 40 of the heat pump will push the working medium from the fifth working space 56 into the sixth working space 57, through the open delivery valve 50 of the upper cylinder head 46, and also through the suction valve 49 of the upper cylinder head 47 of the smaller working cylinder 41. The compression is realized between the two working cylinders, between the two, different volume capacities working spaces 56, 57, because of the pistons 42, 43, which are moving in an opposite direction to each other. The working medium under compression will be heated up, while the greater piston 42 is carrying out work on it.

The second stage - the isochore heat-loss - is carried out simultaneously with the fourth stage.

The stage of the isochore heat-loss is carried out during the movement of the piston 43 of the smaller working cylinder 41 of the heat-pump, from its lower dead point position, to its upper dead point position, while the piston, moving in the smaller working cylinder 41 , will push the working medium which is in its way from the sixth working space 57 - just in front of the piston - into the seventh working space 58 - just behind the piston, through the open delivery valve 48 of the upper cylinder head 47, and also through the line 39 - which serves for giving off the heat - of the heat-exchanger 37 of the heat-pump - which also serves for giving off the heat -, as well as through the suction valve 55 of the lower cylinder head 45. The working medium, which flows through the heat-exchanger 37, will give off heat to the atmosphere, or to any external heat-reservoir. As the volume of the working medium may not be changing during the heat-removal, the temperature and the pressure of the working medium will decrease, in consequence of the heat-energy removal.

5 The third stage is the isentropic expansion, which is carried out simultaneously with the first stage. During this expansion, the piston 43 of the smaller working cylinder 41 is moving downwards from the upper dead point position, while at the same time the piston 42 of the greater working cylinder 40 is moving upwards from the lower dead point position. The piston 43 of the smaller working cylinder

10 41 , moving downwards from the upper dead point position, will push the working medium from the seventh working space 58 into the eighth working space 59, which is located under the upwards moving piston 42 of the greater working cylinder 40, through the open delivery valve 54 of the lower cylinder head 45, of the smaller working cylinder 43, and also through the open suction valve 53 of the

15 lower cylinder head 44 of the greater working cylinder 40. As the volume of the seventh working space 58 is smaller than the volume of the eighth working space 59, therefore the working medium will be expanding, during the process. Because of this expansion, the temperature and the pressure of the working medium will be decreasing. The expanding working medium will cool down, and is carrying

20 out work on the greater piston, in the meantime.

The fourth stage is the isochore heat absorption, which is carried out simultaneously with the second stage. This stage of the isochore heat-removal is realized during the movement of the piston 42 of the greater working cylinder 40 from its upper dead point position towards its lower dead point position, while the

25 piston 42 moving downwards in the greater working cylinder 40 will push the working medium which is in its way from the eighth working space 59 into the fifth working space 56 - which is just behind the piston, which means, that the working medium will be pushed just behind itself -, through the open delivery valve 52 of the lower cylinder head 44, and also through the line 38 - serving for

30 taking up heat - of the heat-exchanger 36, heated by an external heat-source; as well as through the open suction valve 51 of the upper cylinder head 46. The working medium, which flows through the line 38 of the heat-exchanger 36, will take up absorb heat from an external source. As the volume of the working medium may not be changing during the heat-transfer, therefore the temperature and the pressure of the working medium will increase, by the influence of the absorbed heat-energy.

The heat-pump shown in Figure 7 may also be operated as heat engine, if the heat-exchanger 37 giving off heat is heated, and, at the same time, the heat- exchanger 36, taking up heat is cooled.

In the next example, implementation of a Carnot cycle will be explained with reference to the apparatus in Fig.8 based on the principle described above. This apparatus may be operated as a heat engine, but also as a heat-pump, depending upon the fact, whether it is operated as a heat engine, applying heated heat-exchanger and cooled heat-exchanger and taking out mechanical work from the shaft of the apparatus, or operating it as a heat-pump, when the shaft of the apparatus is rotated by mechanical work and the amount of heat removed through the cooled heat-exchanger, is obtained through the heated heat- exchanger.

Figure 8 shows the double-operated working cylinders, which were applied in the previous examples. In this case the cylinders, which could be used as double- operated cylinders, as well, are only used as single-operated working cylinders, in such a way, that only the working spaces above the pistons are utilized within one cycle. However, at the same time, between the working spaces under the pistons another independently operable thermodynamic cycle may be realized. But still, apart from this, the basic idea of the invention is the same.

The four stages of the Carnot-cycle are realized in separate stages always between two co-operating working spaces, in accordance with the invention.

During one half-turn of the operation, the first working space 72 and the second working space 73 will co-operate simultaneously with the third working space 74 and the fourth working space 75and during the second half-turn of the operation, the second working space 73 and the third working space 74 will co-operate simultaneously with the fourth working space 75 and the first working space 72.

The co-operation of the working spaces will be determined by the open or closed position of the control valves. The volume capacities of the working spaces 72, 73, 74, 75 of the co-operating working cylinders 76, 77, 78, 79of different volume capacities are changed by the pistons 68, 69, 70, 71 of different diameters. The pistons are connected to a common crank shaft 94, wherein the first piston 68 and the third piston 70 include a 180° angle with the second and the fourth pistons 69, 71. The pistons have their own crank mechanisms provided with cranks driving-rods and piston-rods. Consequently, the pistons 68, 69, 70, 71 are interlocked with each other.

The principle of the connection of the co-operating working spaces by controlled valves and heat-exchangers is entirely identical with the structure described previously therefore no more details will be explained here again.

According to the invention, a four-stage heat engine cycle is implemented, wherein the stages are identical with the four stages of the Carnot cycle. These stages are in ideal case an (essentially isotherm) expansion, an (adiabatic) isentropic expansion, a (essentially isotherm) compression, and an (adiabatic) isentropic compression

During isotherm expansion the first piston 68 is moving upwards from its lower dead point position. The suction valve 81 of the upper cylinder head 80 of the first working cylinder 76 is in closed position, while the delivery valve 82 is in open position. The first piston 68, which is moving in upwards direction, will push the working medium from the first working space 72 into the second working cylinder 77, through the delivery valve 82, which is just open for this period of time, and also through the heated heat-exchanger 83, and through the suction valve 85 of the upper cylinder head 84 of the second working cylinder 77; and into the second working space 73 above the second piston 69, which is moving downwards from its upper dead point position, because of the opposite cycle- phase. We have to transfer possibly such an amount of heat to the working medium, through the heated heat-exchanger 83, which amount would be needed for the expansion of the working medium to be considered as isotherm, or, just simply saying, it should approximate the isotherm character, as perfectly as possible. As the diameter of the downwards moving second piston 69 is greater consequently its volume capacity is also greater than the volume capacity of the first working cylinder 76, therefore the flowing working medium is carrying out an expansion, while this fills in the volume capacity of the second cylinder 77. During this half-turn the suction valve 85 of the upper cylinder head 84 of the second working cylinder 77 is in its open position, while the delivery valve 86 is closed.

5 During isentropic expansion, when the second piston 69 reaches the lower dead point position, then the suction valve 85 on the upper cylinder head 84 of the second working cylinder 77 will close, and the delivery valve 86 will open. Later the upwards moving second piston 69 will push the working medium from the second working space 73 into the third working space 74, which is above the io downwards moving third piston 70, through the open delivery valve 86, and also through the suction valve 88 of the upper cylinder head 87 of the third working cylinder 78. The diameter of the third piston 70 is greater than the diameter of the second piston 69, therefore the third working space 74 above the third piston is also greater than the second working space 73 above the second piston.

15 Consequently, the working medium - in the lack of heat removal or heat transfer - carries out an expansion process, which may be considered as isentropic, when the second piston 69 reaches the upper, while the third piston 70 reaches the lower dead point position. When the lower dead point position is reached, the suction valve 88 of the upper cylinder head 87 of the third working cylinder 78

20 closes, and at the same time the delivery valve 89 opens.

During isothermal compression, the third piston 70 will again move upwards, while it pushes the working medium from the third working space 74 into the fourth working space 75, which is above the fourth piston 71 , through the open delivery valve 89, through the open suction valve 92 of the upper cylinder head 25 91 of the fourth working cylinder 79, and also through the cooled heat-exchanger 90.

While the piston is moving downwards, the suction valve 92 of the fourth working cylinder 79 is open, the delivery valve 93 is closed.

The diameter of the fourth piston 71 is smaller than the diameter of the third

30 piston 70, therefore the third working space 74 is also smaller than the fourth working space 75, as a result of this fact the working medium is compressed. P preferably such an amount of heat is removed from the working medium- flowing through the cooled heat-exchanger 90, which amount would be needed for an isothermal or nearly isothermal compression.

During isentropic compression, when the fourth piston 71 reaches the lower dead point position, then the suction valve 92 on the upper cylinder head 91 of the fourth working cylinder 79 will close, and the delivery valve 93 will open. Later the upwards moving fourth piston 71 will push the working medium from the fourth working space 75 into the first working space 72, which is above the downwards moving first piston 68, through the open delivery valve 93, and also through the suction valve 81 of the upper cylinder head 80 of the first working cylinder 76. In the meantime, the suction valve 81 of the upper cylinder head 80 of the first working cylinder 76 is open, while the delivery valve 82 is closed. As there is no heat-exchanger between the fourth 79 and the first 76 working cylinders, and the first piston 68 of the first working cylinder 76 is smaller than the fourth piston 71 of the fourth working cylinder 79, therefore the working medium is suffering a compression, which may be considered as isentropic.

With this step the working medium closed the circuit, and the whole process will be repeated.

Depending on the opening and closing order of the control valves or the direction of rotation, the apparatus is operated as a heat engine or as a heat pump. If the apparatus originally operated as a heat engine is operated by mechanical work, and the original direction of rotation is not changed, then the flow-direction of the working medium may be changed, by changing the opening and closing order of the valves; then, the working medium will flow in the opposite direction between the co-operating working spaces. In this case the apparatus operates as a heat pump. This opportunity is of special importance in case of certain applications.

The apparatus - when it is operated as a heat pump - will dissipate the mechanical work obtained from the environment and transformed into heat through the originally heated heat-exchanger; or, in the other case, the apparatus will remove the amount of heat from the environment through the originally cooled heat-exchanger. The apparatus implementing a Carnot thermal cycle - as shown in Figure 8 - may be operated as a heating apparatus, if the working spaces above the piston are operated as heat engine, and regarding the working spaces under the piston are operated as heat pump. Similarly, if the heat pump - shown in Figure 7 - is driven by any of the heat engines described here previously, then the heat pump will operate as a heating apparatus. The result is the same if a Stirling heat engine and a Stirling heat pump are operated together, for the purpose of heat- production or any heat engine - operating according to the principles of this invention - is operated together with any heat pump - operating according to the principles of this invention. Any apparatus, which operates in this way, and consists of a heat engine and of a heat pump, which operate like this, will keep the contact with its environment through - at least - three heat-exchangers. One heat-exchanger will be used for transferring heat to the heat engine, while the other heat-exchanger will serve for removing the heat from its environment by the heat pump, and the third heat-exchanger will be used for giving off that heat energy - at an identical, or similar temperature -, which energy was not used by the heat engine, or which was removed from its environment by the heat pump. When the apparatus is used as a heating apparatus, the heat engine will drive the heat pump, with the purpose, that the amount of heat which could not be used for the operation of the heat engine, together with that amount of heat which was removed from the environment by the heat pump, could be used for heating purposes. The cooling of the heat engine and of the heat pump in these cases is carried out by the same heating system. In this case, a significantly larger amount of heat may be used for heating purposes, than the heat energy of the fuel fired with the purpose of operating the heat engine, because that amount of heat, which was given off as heat loss during the operation of the heat engine, will be utilized by the heating system. The mechanical work - produced by the heat engine - will again be transformed into heat energy, during the driving of the heat pump, - which again, will be utilized by the heating system. Until this point, there is no relevant and significant heat-loss, the heat-energy of the burned fuel may be fed into the heating system as an amount of heat energy, of which the volume may be similar as in the case of a traditional boiler. During the process, when the amount of energy - which was transformed into mechanical work by the heat engine - is consumed, the heat pump is removing heat from the environment, which heat will be raised up to a higher temperature level, and will also be transferred to the heating system; which means, that the heat energy - which is removed from the environment by the heat pump - will be evolving as an energy gain. The apparatus, which consists of the heat engine and of the heat pump, may be operated directly with using heat energy, therefore that amount of heat, which is given off by the heat engine, will not be considered as energy loss.

Finally, some open caloric cycles will be described, which may be realized according to the invention. The structural elements and their operation, are the same as described earlier in this description. Accordingly, the pistons - which are changing the volume capacities of the working spaces - are in an interlocked- type connection with each other, the working spaces are connected to each other - or are separated from each other or from the environment - by controlled valves, where the order of these connections will depend upon the realization order of the thermal cycle. The volume capacities of the working spaces - connected, to each other by the valves - are changing in opposite direction, if being a heat engine, or if being a heat pump; because it will remove the heat energy from the working medium, obtained from the environment. Thus, in this case heated heat-exchanger is not present in the system, because the energy that would be needed for the operation will be supplied into the system apparatus as mechanical work.

When an open heat engine cycle is realized, in the simplest case only two working spaces are co-operating, in two working cylinders, which have different volume capacities. Within the suction stroke, the increasing volume capacity working space will be connected to the environment. While within the work- stroke, during the heat-transfer, the first and the second working spaces are connected to each other, wherein the volume capacities of the spaces are changed in counter-operation. The heat-transfer may be realized through the wall of the working space, or through the heat-exchanger, which is arranged between the working spaces, or, even with injecting the fuel into the working space, using internal combustion. During the exhaust stroke, the decreasing volume capacity second working space is connected to the environment. This way, the thermodynamic cycle contains a suction stroke, a heated expansion, and an exhaust stroke, as well. There is no compression work, and the cycle will be closed through the environment.

The apparatus may be operated with a significantly better efficiency, if the previous cycle is supplemented by an isochore heat-transfer stage, realized with the purpose of achieving the regenerative heat recovery. In this case, the open cycle - during each turn of the motor - will contain a suction stroke, an isochore heat-transfer stroke, a heated expansion stroke, and an exhaust stroke. If the isochore heat-transfer stroke is heated with the remaining heat of the working medium leaving during the exhaust stroke, then the heat recovery will be of regenerative character, which could significantly increase the efficiency.

During the operation of the apparatus according to the invention - always those working spaces are connected to each other, the volume capacities of which are changed in opposite direction. During the suction stroke, the first working cylinder will suck the working medium into the first working space, form the environment, while the piston is moving downwards. Following this step the piston in the first working cylinder is moving upwards, and pushes the working medium out from the first working space, through the valves and the counterflow heat-exchanger between the valves, into the second working space located above the downwards moving piston in the second working cylinder. The size of the first working space has preferably the same volume capacity, as the second working space. In the meantime, heat-exchange of a regenerative heat recovery character is carried out between the exhaust working medium, flown through one of the lines of the heat- exchanger, and the working medium, which just flows into the second working space through the other line of the heat-exchanger. Because of the heat-transfer, which is carried out at constant temperature, the pressure of the working medium will increase. Exactly at this point, a valve switch over is carried out. Following this, the piston, which is moving upwards in the second working cylinder, will push this working medium of increased pressure (due to the temperature- increase)from the second working space into the space above the third piston, moving downwards in the third working space having a larger volume capacity than the previous one. In the meantime, the working medium carries out expansion. During this expansion, the working medium has to be heated by any known method (heat-transfer, by a heat-exchanger, or internal combustion). Because of the continuous heat-transfer, the realized process is a heated type expansion. At this moment, there again the valves are switched over. Finally, - within the exhaust stroke -, the piston moving upwards in the third working cylinder, will push the working medium from the third working space into the environment, through the heat-exchanger for the regenerative-type heat- recovery; in the meantime, the working medium - which flows towards the environment - carries out a heat-exchange with the working medium, flowing into the second working space from the first working space. The switch over of the valves are carried out in the upper and lower dead point position of the pistons, which valves are directing the flow of the working medium.

In open thermodynamic cycles heat pumps will suck in pre-heated or ambient temperature air into the first working space. Then this sucked-in working medium will be adiabatically compressed into the second working space. Then the isothermal compression to the third working space takes place. That amount of heat removed during the isothermal compression, will be the useful heat-volume, produced by the heat-pump. Following this, the working medium will be adiabatically expanded into the fourth working space. Later the working medium will be pushed out form the fourth working space into the environment.

The good cooling capability of the low heat-energy content of the working medium of the heat-pump - forwarded to the environment may be used for the cooling of the working medium of the heat-engine operating the heat-pump. In this way the thermal efficiency of the heat engine may be increased.

In case of Diesel engines, when open cycles are realized, the heat exchanger for heating and cooling of the heat engine will be left out from the system, because the heat-input, which would be needed for the operation, will be provided by the chemical reaction between the fuel and the sucked-in air - while the heat output is carried out together with the exhausted working medium. Four working cylinders of different volume capacities are necessary for the realization of the internal combustion open thermodynamic cycle, wherein three of these cylinders have co-operating working spaces. The structure of this apparatus is based on the principle described previously. Here too, the working spaces are alternately connected to the previous or following working space, but the heat-exchangers are missing. The first working space - when it is increasing - is connected to the environment, however, when it is decreasing, it is connected to the succeeding working space. The three co-operating working spaces - in one half-turn - will be connected to the preceding working space, while in the other half-turn they will be connected to the succeeding working space. The last working space - when it is increasing - is connected to the preceding working space, while in that case, when it is decreasing - it will be connected to the environment. The operation - differently from the traditional internal combustion engines - does consist of five strokes. These are: suction, compression, heated expansion, adiabatic expansion and exhaust strokes. It means that two working strokes belong to each turn of the motor. In the first stroke, the downwards moving piston of the first working cylinder will suck in the working medium from the environment (in this case air). In the second stroke, the upwards moving piston of the first working cylinder will compress the working medium into the second working cylinder, which has a smaller volume capacity. During this compression, the working medium will be heated up. At the lower dead point position of the piston of the second working cylinder the fuel will be sprayed into the cylinder, which in that moment will ignite, and will start to burn. Within the third stroke, the upwards moving piston of the second working cylinder will compress the burning fuel-air mixture into the third working cylinder, which has a greater volume capacity. In the meantime, the burning mixture will be expanding. The heated expansion will practically depend upon the amount of the combustion heat of the sprayed-in fuel, and also upon the speed of the combustion. This process may be very precisely controlled by common-rail injection systems. In the fourth stroke, the upwards moving piston of the third cylinder will push the working medium into the fourth working cylinder, which has a still larger volume capacity. During this process, the working medium will adiabatically expand. In the fifth stroke, the upwards moving piston of the fourth working cylinder will exhaust the working medium into the environment.

The above Examples show that the apparatus according to the invention has an advanced character with respect to the state of art in many aspects: • the working medium is divided into at least two parts by controlled valves,

• the controlled valves always connect those working spaces together, where the volume of one space is decreasing, and that of another space is increasing,

• due to the above, those parts of the working medium, which are separated by the controlled valves, will always flow into the same direction between the working spaces,

• each stage of the caloric cycle will always be realized during the connection of the same two working spaces, and

• the apparatus can implement caloric cycles in separated, independent stages.

The kind of thermodynamic cycle realized according to the invention, will depend upon the order of the individual stages. The thermodynamic cycle may only be realized because the independent stages between the co-operating working spaces of adversely variable volume capacities are connected in series, in such a way, that the working medium should always turn back to its starting point. The individually realized stages may be adiabatic, isothermal, isobar or isochore stages; supposing an ideal thermodynamic cycle. Ideal theoretical thermodynamic stages can, of course, not be realized, but still, the aim of this invention is to approximate these stages as close to the ideal cases, as possible.

Claims

WHAT WE CLAIM IS

1. A process for implementing thermodynamic cycles, wherein volume capacities of working spaces are changed; expandable working medium is flowing between the working spaces, and heat-transfer and / or heat- removal is carried out; characterized in that

• the volume capacities of the co-operating working spaces are changed in about a 180 degree counter-stroke,

• the working medium is driven from a decreasing volume capacity working space into an increasing volume capacity working space, in an order, which complies with the different stages of the thermodynamic cycle, and

• every stage of the thermodynamic cycle is realized separately, in a way, that

• always the same stage of the cycle should take place between two working spaces.

2. Process according to claim 1 , characterized in that the working medium is divided by valves into at least two identical parts.

3. Process according to claim 1 or 2, characterized in that the working medium is always led in the same direction, between the working spaces.

4. Process according to any of claims 1 to 3, characterized in that the heat- exchange is carried out alternately between two parts, which contain the same material substances, or between the two parts and the external atmosphere.

5. Process according to any of claims 1 to 4, characterized in that the heat- exchange between the parts is carried out through a heat pump.

6. Process according to any of claims 1 to 5, characterized in that the state of the condition of the working medium is changed during the process.

7. Process according to claim 1 , for the realization of an open thermodynamic cycle, characterized in that one part of remaining heat of the working medium leaving the cycle, will be utilized for the heating of the working medium of the thermodynamic cycle.

8. Process according to claim 7, characterized in that the amount of heat needed for the operation of the process will be received from the heat energy of the burning of the fuel added to the working medium in one of the working spaces.

9. Process according to claim 7, characterized in that the working medium, which leaves the thermodynamic cycle, at a temperature which is lower than the ambient temperature, will be used for the cooling of the working medium of the heat engine, which in turn operates the heat pump.

10. Process according to any of claims 1 to 9, characterized in that every stage of the cycle contains at least two working phases.

1 1.Apparatus for implementation of the process according to any of claims 1 to 6, characterized in that:

• it contains working spaces with variable volume capacities(13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96), and valves (3, 4, 5, 6, 7, 8, 9, 10, 49, 50, 51 , 52, 53, 54, 55, 81 , 82, 85, 86, 88, 89, 92, 93, 98, 99, 101 , 102) between the working spaces(13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74,

75, 95, 96),

• the elements changing the volume capacities (13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96), are interlocked with each other,

• the individual working spaces (13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96) are connected in series,

• the last working space (16, 59, 75, 96) is connected to the first one (13, 56, 72).

12. Apparatus for implementation of the process according to any of claims 7 to 10, characterized in that • it contains working spaces with variable volume capacities, and valves, between the working spaces,

• the elements changing the volume capacities of the working spaces, are in an interlocked connection with each other,

• the individual working spaces are connected in series,

• the apparatus contains at least two such working spaces, which are connected to the ambient atmosphere.

13. Apparatus according to claim 12, characterized in that apparatus it contains at least one working space, which is not connected to the ambient atmosphere.

14. Apparatus according to claim 12 or 13, characterized in that apparatus it contains elements for mixing fuel into the sucked in working medium.

15. Apparatus according to any of claims 11 to 14, characterized in that at least one of the elements enclosing the working spaces (13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96) is connected to an external heat-source, of which the temperature is higher than that of the working medium.

16. Apparatus according to any of claims 11 to 15, characterized in that at least one of the elements enclosing the working spaces apparatus (13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96) is connected to an external heat-source, of which the temperature is lower than that of the working medium.

17. Apparatus according to any of claims 11 to 16, characterized in that it contains a heat pump.

18. Apparatus according to any of claims 11 to 17, characterized in that the walls of the working spaces (13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75,

95, 96) are working cylinders (1 , 2, 40, 41 , 76, 77, 78, 79) and pistons (11 , 12, 42, 43, 68, 69, 70, 71 ).

19. Apparatus according to claim 18, characterized in that the working cylinders (1 , 2, 40, 41 , 76, 77, 78, 79) are of double-operation type, wherein the working spaces (13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96) are arranged above and under the pistons (11 , 12, 42, 43, 68, 69, 70, 71 ) belonging to the cylinders.

20. Apparatus according to claim 18 or 19, characterized in that the pistons (11 , 12, 42, 43, 68, 69, 70, 71 ) are connected to a common drive (104).

21. Apparatus according to claim 20, characterized in that the pistons (11 , 12, 42, 43, 68, 69, 70, 71 ) are connected to a common crankshaft (27, 94) in about a 180 degree counter stroke.

22. Apparatus according to any of claims 11 to 21 , characterized in that it contains at least one heat-exchanger (29, 36, 37) between two working spaces (13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96).

23. Apparatus according to any of claims 11 to 21 , characterized in that it contains at least one heat-exchanger (28, 32, 33, 34, 66, 83, 90) connected to a working space on the one side and to the external atmosphere on the other side.

24. Apparatus according to any of claims 11 to 23, characterized in that the closed valves (3, 4, 5, 6, 7, 8, 9, 10, 49, 50, 51 , 52, 53, 54, 55, 81 , 82, 85, 86, 88, 89, 92, 93, 98, 99, 101 , 102) divide the working spaces (13, 14, 15,

16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96) at least into two parts.

25. Apparatus according to any of claims 11 to 24, characterized in that the valves (3, 4, 5, 6, 7, 8, 9, 10, 49, 50, 51 , 52, 53, 54, 55, 81 , 82, 85, 86, 88, 89, 92, 93, 98, 99, 101 , 102) are controlled by the upper or the lower dead point position of the pistons (11 , 12, 42, 43, 68, 69, 70, 71 ).

26. Apparatus assembled from apparatuses according to any of claims 11 to 25, which consists of two parts, wherein one part is a caloric cycle heat engine and the other part is a caloric cycle heat pump, characterized in that it contains at least one heated and one cooled working space (13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96) each in the heat engine and the heat pump.

27. Apparatus assembled from apparatuses according to any of claims 11 to 25, which consists of two parts, wherein one part is a caloric cycle heat engine and the other part is a caloric cycle heat pump, characterized in that apparatus it contains at least one heated working space (13, 14, 15, 16, 56,

57, 58, 59, 72, 73, 74, 75, 95, 96) in the heat engine, and at least one cooled working space (13, 14, 15, 16, 56, 57, 58, 59, 72, 73, 74, 75, 95, 96) in the heat pump.