WO2002066835A1

WO2002066835A1 - A method for monitoring a pump and a pump using the method

Info

Publication number: WO2002066835A1
Application number: PCT/CN2002/000039
Authority: WO
Inventors: Donggui Li
Original assignee: Donggui Li
Priority date: 2001-02-19
Filing date: 2002-01-23
Publication date: 2002-08-29
Also published as: CN2466390Y

Abstract

The present invention relates to a method for monitoring a pump and a pump using the method. In order to precisely monitor the operation of a pump without using a flow sensor, according to the present invention, in a pre-programmed processor are pre-stored character diagram of the pump, density of the fluid as well as control parameters etc. During operation pressure at outlet and inlet of the pump is measured. Performance parameters are evaluated by processor according to said pressure, density, control parameter and character diagram. The evaluated parameters are used to control the pump. The pump according to the present invention comprises pressure sensors (6,7) equipped at the outlet and inlet of the pump (1), sensors for detecting fluid density in the working circumstance and a monitoring device (8) which receives signals from each sensors. The monitoring device comprises power system module (801), data collecting module (802), pre-programmed processor (803) and control operating module (804) etc. The idea of the present invention is maily used in industrial flow pump and monitoring of the same.

Description

Method for monitoring pump and pump using the same TECHNICAL FIELD

The present invention relates to a method for monitoring hydraulic performance such as a flow rate, a head, a cavitation margin, and a power of a pump, and a pump using the method. Background technique

The hydraulic performance parameters of traditional mechanical pump products, especially industrial process pumps, are manually adjusted by valves through the valve to a flow or head that can meet the process requirements; or they can be measured and adjusted manually according to the flowmeter in the pipeline. Flow and lift required by the process. The former method can only vaguely convey liquid, but cannot accurately convey liquid quantitatively, resulting in low product quality or waste of materials due to excessive conveyance. Although installing a flow meter in the pipeline can quantitatively convey liquid, the engineering cost improve.

At present, parameters such as the flow, head and power of the pump can also be monitored in some processes, and some are also controlled automatically. In these monitoring and automatic control methods, the pump body is connected to the prime mover through a coupling, an electric valve is connected to the pipeline connected to the pump body outlet, and a control circuit is connected to the prime mover and the electric valve. The input of the control circuit The signal must be supplied by a pressure sensor and a flow sensor installed on the outlet pipe. The setting of the sensor not only makes installation and maintenance of the entire equipment troublesome, but also because the cost of the flow sensor is high, the monitoring cost of the entire equipment is correspondingly increased.

Another disadvantage of the above-mentioned existing methods is that the accuracy of monitoring the hydraulic performance parameters of the pump is not high. This is because the measurement is to install a flowmeter on the pipeline, such as a worm wheel flowmeter, a laser flowmeter, or an electromagnetic flowmeter. No matter which type of flowmeter is based on the physical properties or movement of the fluid in the pipeline Indirect measurement based on scientific principles, rather than direct measurement based on hydraulic performance curves determined by the design and manufacture of hydraulic components of the pump. The former indirect measurement method has many factors that affect its measurement accuracy, and if it can be directly measured, it has a single factor that affects its measurement accuracy. Compared with the indirect measurement method, it can There is higher measurement accuracy, and thus higher monitoring and control accuracy. Summary of the invention

Therefore, a first object of the present invention is to provide a method for realizing accurate automatic monitoring without using a flow sensor or a power sensor.

In order to achieve the object, the present invention provides a method for monitoring a pump, which includes the following steps: A pre-programmed processor is provided, in which a characteristic parameter curve, fluid density or control of the pump is stored in advance or input and stored during use. Parameters, or a combination of them; measuring the pressure at the outlet end and the inlet end of the pump, and transmitting the measured values to the pre-programmed processor; the pre-programmed processor according to the characteristic parameter curve stored therein, the fluid density, and The pressure value is input to calculate various performance parameters of the pump; output the calculated performance parameters, or / and drive a control drive device that controls the operation of the pump based on the calculated performance parameters and control parameters The control driving device controls the frequency converter of the frequency conversion motor that is the prime mover of the pump, or controls the electric valve installed on the pipeline connected to the pump, thereby controlling the operation of the pump.

Because the pressure is measured in real time at the outlet and inlet positions of the pump body, and the pressure has a certain functional relationship with the performance parameters of the pump such as the head, this method is more accurate than the existing monitoring methods and can achieve accurate quantification Transporting liquids.

Another object of the present invention is to provide a pump that realizes accurate automatic monitoring without using a flow sensor and a power sensor.

In order to achieve the object, the present invention provides a pump, in which a pressure sensor is respectively provided at an inlet end and an outlet end of a pump body, and an output signal of the pressure sensor is connected to a monitoring device, and the monitoring device includes: a power source for providing power A system module; a data acquisition module that receives the output of the pressure sensor; a processor that processes data input from the data acquisition module according to the hydraulic performance characteristic curve and fluid density stored therein; and an output that receives the output of the processor Module, the output module is used to output information to the outside.

Another object of the present invention is to provide a power sensor without using a flow sensor. Intelligent pump for precise monitoring.

In order to achieve the object, the present invention provides a pump, in which a pressure sensor is respectively provided at an inlet end and an outlet end of a pump body, and an output signal of the pressure sensor is connected to a monitoring device, and the monitoring device includes: a power source for providing power A system module; a data acquisition module that receives the output of the pressure sensor; a processor that processes data input from the data acquisition module according to the characteristic curve, fluid density, and control parameters stored therein; and a processor that receives the output of the processor A control drive module, which is used to output information to a device that controls the operation of the pump.

Specifically, an electric valve that controls the flow rate may be connected to the control drive module, or a variable frequency motor serving as a prime mover of the pump may be connected to the control drive module through a frequency converter.

In a preferred embodiment, the above-mentioned pump monitoring device may further include an input module for inputting control parameters such as flow rate and Yang Cheng during operation.

In another preferred embodiment, the data acquisition module may further receive an input of a fluid density sensor provided on another good service site, such as a pipeline, so that the processor performs data processing according to the fluid density obtained in real time.

By using the above pump, it is not necessary to use expensive flow sensors and power sensors, and it can complete accurate monitoring and control of various parameters, thereby reducing the cost of the entire pump and monitoring device. BRIEF DESCRIPTION OF THE DRAWINGS

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In the drawings:

FIG. 1 is a schematic diagram of a pump, an electric valve and a prime mover of the present invention;

Figure 2 is used to explain the monitoring method and the working principle of the pump of the present invention;

Country 3 is a block diagram of the method of the present invention;

Fig. 4 is a block diagram showing a configuration of a monitoring device in the pump of the present invention. detailed description

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

The method for controlling a pump provided by the present invention includes the following steps:

a) Provide a pre-programmed processor, in which the hydraulic performance characteristic parameter curve, fluid density or control parameter of the accurately mapped pump is stored in advance or input and stored during use, or a combination thereof;

b) measuring the pressure at the outlet end and the inlet end of the pump, and transmitting the pressure value to the pre-programmed processor;

C) The pre-programmed processor calculates various performances of the pump based on the characteristic parameter curve and fluid density stored therein, and the pressure value is input.

d) outputting the calculated performance parameter, or / and driving a control drive device that controls the operation of the pump based on the calculated performance parameter and control parameter, the control drive device controls the frequency conversion of the prime mover of the pump The frequency converter of the motor, or the electric valve installed on the pipeline connected to the pump, thus controls the operation of the pump.

According to a preferred embodiment, the fluid density passing through the pump can also be measured in real time in step b). For example, a fluid density sensor is installed at the inlet of the pump to measure the fluid density at any time, and the measured value replaces the pre-stored in the processor. Fluid density, so that the method can flexibly adapt to different fluids, including adapting to small changes in fluid density in the same process flow, so as to accurately monitor the operation of the pump.

In order to implement the above method, the present invention also provides a pump. For clarity, both the method and the pump will be described in the following description.

FIG. 1 shows a pump, an electric valve 5 and a prime mover 3 of the present invention. The prime mover 3 may be a variable frequency motor. Among them, the pump body 1 is connected to the prime mover 3 through a coupling 2, an electric valve 5 is connected to the pipeline 4 connected to the pump body 1, and pressure sensors are provided at the inlet end and the outlet end of the pump body 1, respectively. The output signals of 6, 7, pressure sensors 6, 7 are connected to the monitoring device 8. As shown in FIG. 4, the monitoring device 8 mainly includes: a power supply system module 801 that provides power; a data acquisition module 802 that receives the outputs of the sensors 6, 7 mounted on the pump body 1, which may be any suitable existing A technical implementation, such as an analog-to-digital conversion module; a processor 803 that processes data input from the data acquisition module 802 according to a characteristic curve and a fluid density stored therein. The principle of the processor 803 processing data will be described in detail below.

When the pump of the present invention is only required to have an automatic monitoring function, the monitoring device further includes an output module for receiving and outputting the output data of the processor 803, so that the operator can understand the operation status of the pump, and even Manual control or adjustment of the production process according to the information obtained, so as to ensure that the production of industrial processes and their products meet the expected design goals and product quality.

In FIG. 4, the output module is a Yuxian module 805, which is used to display automatic monitoring data. In this way, the monitoring device can automatically and intuitively display parameters such as the flow rate, head, and power consumption of the pump. The output module may also be a printing module, which is used to print out the automatically detected data.

The monitoring device may further include a storage module for storing the data of the pump within a certain period for viewing and printing.

Of course, the above-mentioned various output modules and storage modules may be used in combination.

When the pump needs to have an intelligent monitoring function, the monitoring device further includes a control driving module 804. The control driving module 804 is configured to output command information to a device that controls the operation of the pump, thereby controlling the operation of the pump. The control driving module can be implemented by any suitable existing technology, such as a digital-to-analog conversion module. Of course, the pump for implementing intelligent monitoring may also have the above-mentioned various output modules, storage modules, and any combination thereof.

Specifically, the electric valve 5 for controlling the flow rate may be connected to the control driving module 804, or a variable frequency motor serving as the prime mover (3) of the pump may be connected to the control driving module 804 through an inverter 9 (the connection relationship is in (Not shown in Figure 1).

Whether used for monitoring or control, all monitoring devices can include an input module 806, such as a keyboard, allows certain parameters to be entered later. For example, you can enter the density of the fluid. This allows the pump to accurately monitor different fluids. As another example, when intelligent monitoring of a pump is required, parameters to be controlled may be input from a keyboard, such as a pump flow rate and a lift control value 302. As another example, when the characteristic curve of the pump changes, or when the monitoring device is used for different pumps, a new characteristic parameter curve may be input.

The monitoring device may further include a data communication module 807, which is used to implement communication of each pump in the pump group, and may be connected to a central processing unit, thereby implementing monitoring and control of the pump group.

The following describes the data processing process, that is, the method of the present invention, and the data processing principle.

As shown in FIG. 3, the pressure signals 303 measured by the pressure sensors 6, 7 at the outlet end and the inlet end of the pump body 1 are input into a monitoring device 8 (the processor in the method of the present invention is part of the monitoring device), The monitoring device 8 processes the signals and then outputs data (not shown in the figure). When used for intelligent monitoring, the control driving device in the monitoring device sends instructions to the electric valve to control the opening and adjustment of the electric valve to control the operation of the pump; and / or sends a frequency modulation instruction 304 to the inverter 9 and is controlled by the inverter The frequency of the variable frequency motor is used to control the pump.

The processor 803 is, for example, a microcontroller processor, in which pre-programming is performed according to the present invention. After understanding the principles described below, a person of ordinary skill in the art can complete the pre-programming.

The programming of the processor 803 is based on a mathematical model of the hydraulic performance parameter curve of the pump. This mathematical model is established by accurately measuring hydraulic performance parameters before the pump leaves the factory. The specific mathematical model is as follows:

For a series of flow points, R ₂ R _n (n is a natural number):

Relation curve between head (H) and flow (Q-curve in Figure 2): When the flow is 0-1 ^, the head HA ^ K ^ Q; when the flow is Ri-R ₂ , the head H = A ₂ + K ₂ Q ......; When the flow is R _n _ _r R _n , the head H = A _n + K _n Q. Among them, A, K is a characteristic constant.

The relationship between the cavitation allowance (PSH) and the flow rate (Q) (PSH-Q curve in Figure 2): When the flow rate is 0-1 ^, N SH-BfM ^ Q; When the flow rate is I ^-R ₂ , NPSH = B ₂ + T ₂ Q ……; When the flow is R ^ — R _n , NPSH = B _n + T _n Q, where B and T are characteristic constants.

The relationship curve between the water test value and the flow rate of the motor power N (the H-Q curve in Figure 2): when the flow rate is 0—, ^ water = ( ₁ +1; ₁ 0; when the flow rate is 1 ^ _ 11 ₂ N Water = C ₂ + U ₂ Q ……; When the flow rate is-R _n , NC _n + U _n Q, where C and U are characteristic constants. Let the liquid density be P in the working state, then The actual power is NP = PN water.

The processor 803 may store in advance the three curves tested before the pump leaves the factory and the user-provided fluid density 301 (see FIG. 3). When the pressure sensors 6, 7 at the inlet and outlet ends of the pump body 1 transmit the pressure signals 303 (FIG. 3) at the inlet and outlet ends to the processor 803, the processor according to the relationship H = (P — P) / P (Where H is the head of the pump, and P and P are the pressures at the outlet and inlet ends of the pump, respectively), and according to the above three relationship curves, calculate the pump flow, cavitation allowance, and actual motor power Performance parameters such as consumption, and then display the parameters as required, and control the drive module 804 according to, for example, the pump flow rate or head control value 302 (see Figure 3) stored in the processor, which controls the electric valve to adjust the flow rate To a predetermined value, thereby achieving the purpose of controlling the operation of the pump. Alternatively, as shown in FIG. 3, the control and drive module may send a frequency modulation instruction 304 to the inverter 9 to control the corresponding motor frequency conversion coefficient and motor speed, thereby ensuring the required operating point, and the operating point falls within the high-efficiency zone.

As mentioned earlier, the characteristic curve, fluid density, and control parameters (flow or head) can also be input at a later stage.

In addition, the data acquisition module may also receive an input of a fluid density sensor provided on a service site such as a pipeline or in a pump body, so that the processor performs data processing according to the fluid density obtained in real time. In addition, the monitoring device may be integrated with the pump, or may be relatively independent from the pump and connected by a line.

The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the above-mentioned range. For example, the monitoring device may not only be connected to a sensor on a pump body; it may also be connected not only to a pressure sensor or a fluid density sensor, but also to, for example, a bearing temperature sensor to implement functions such as alarm; similarly, the The monitoring device can also use the output signal to control other parameters that affect the operation of the pump to ensure its safety and reliability.

Claims

Rights request

A method for monitoring a pump, characterized in that it comprises the following steps:

a) Provide a pre-programmed processor in which the characteristic parameter curve, fluid density or control parameter of the pump is stored or input and stored during use, or a combination thereof;

b) measuring the pressure at the outlet end and the inlet end of the pump and transmitting the measured values to the pre-programmed processor;

c) the pre-programmed processor calculates various performance parameters of the pump according to the characteristic parameter curve and fluid density stored therein, and inputting the pressure value;

The method according to claim 1, characterized in that in the step b), the density of the fluid passing through the pump is also measured in real time, and the measured value is transmitted to the pre-programmed processor.

3. A kind of pump, characterized in that a pressure sensor (6, 7) is provided at the inlet end and the outlet end of the pump body (1), and an output signal of the pressure sensor (6, 7) is connected to a monitoring device (8) ) The monitoring device (8) includes: a power supply system module (801) that provides power; a data acquisition module (802) that receives the output of the pressure sensor; and collects data from the data according to the characteristic curve and fluid density processing stored therein Module

(802) a processor (803) for input data; and an output module receiving an output of the processor, the output module is configured to output information to the outside.

The pump according to claim 3, wherein the data acquisition module further receives an input of a fluid density sensor provided in the service site including a pump body, so that the processor performs an operation based on the fluid density obtained in real time. data processing.

The pump according to claim 3 or 4, wherein the monitoring device further comprises a storage module, an input module (806), a data communication module (807), or a combination thereof, and the input module is used for Enter the characteristic curve, fluid density, control parameters, etc. later.

6. A kind of pump, wherein a pressure sensor (6, 7) is provided at the inlet end and the outlet end of the pump body (1), and the output signal of the pressure sensor (6, 7) is connected to a monitoring device. (8) The monitoring device (8) includes: a power supply system module (801) that provides power; a data acquisition module (802) that receives output from the pressure sensor; and processes according to a characteristic curve, fluid density, and control parameters stored therein A processor (803) for inputting data from the data acquisition module; and a control driving module (804) receiving an output of the processor, the output of the control driving module (804) is connected to the pump body (1) ) The electric valve (5) on the connected pipeline (4), or the inverter of the inverter motor that is the prime mover of the pump.

The pump according to claim 6, wherein the data acquisition module further receives an input of a fluid density sensor provided in the service site including a pump body, so that the processor performs an operation based on the fluid density obtained in real time. data processing.

The pump according to claim 6 or 7, wherein the monitoring device further comprises an output module, a storage module, an input module (806), a data communication module (807), or a combination thereof, and the input module It is used to input the characteristic curve, fluid density and control parameters.