A valve dynamic characteristic test system of a reciprocating liquid pump

Abstract

The application discloses a valve dynamic characteristic test system of a reciprocating liquid pump, and the inlet end and the outlet end of the reciprocating liquid pump are detachably fixed with an inlet valve module and an outlet valve module respectively; the inlet valve module comprises an inlet valve to be tested and a first eddy current displacement sensor for measuring the displacement of the inlet valve core; the outlet valve module comprises an outlet valve to be tested and a second eddy current displacement sensor for measuring the displacement of the outlet valve core; a pressure gauge is arranged on the front of the inlet valve, the rear of the outlet valve and the pump cylinder of the reciprocating liquid pump; the pressure data monitored by the three pressure gauges and the displacement data of the two eddy current displacement sensors are transmitted to a display instrument for real-time display and monitoring, and are transmitted to a control platform. The application can realize the dynamic characteristic test of the inlet and outlet valves of the reciprocating liquid pump under the low-temperature high-pressure harsh working condition and the quick replacement of the valve assembly by using the non-contact eddy current displacement sensor and the detachable valve module.

Description

Technical Field

[0001] This invention belongs to the field of pump and valve characteristic testing technology, and in particular relates to a valve dynamic characteristic testing system for a reciprocating liquid pump. Background Technology

[0002] Inlet and outlet valves are key components of reciprocating liquid pumps. Their function is to open and close the inlet and outlet of the reciprocating liquid pump by means of pressure changes before and after the valves, preventing the pressurized working fluid from flowing backward.

[0003] For example, Chinese patent document CN114673656A discloses a plunger-type reciprocating pump with a liquid seal function, including a pump body, a cylinder liner, and a plunger disposed within the cylinder liner. The plunger slides along the length of the cylinder liner. The pump body has a pump chamber, and the pump body has an inlet check valve and an outlet check valve at both ends. Chinese patent document CN110017256A also discloses a plunger-type reciprocating pump.

[0004] However, the reciprocating piston motion of a reciprocating liquid pump causes the valve to operate in a high-speed alternating flow environment. The valve core motion is affected by many parameters, making it difficult to obtain accurate dynamic characteristics through theoretical calculations. In practical engineering, the performance characteristics of the reciprocating liquid pump are generally measured to infer the rationality of the valve core parameter design. This method has the disadvantages of high cost and poor optimization accuracy, making it difficult to obtain the optimal valve dynamic characteristics.

[0005] Because reciprocating liquid pumps operate at high frequencies, valve strokes and movement times are very short, and valves may need to operate under different temperature and pressure conditions, making experimental testing of their dynamic characteristics extremely difficult. Currently used contact displacement sensors have poor adaptability to harsh environments, while laser displacement sensors are affected by fluid flow.

[0006] For dynamic characteristic testing of valves in reciprocating liquid pumps, it is necessary to be able to quickly and easily modify valve parameters and conduct experiments to obtain the dynamic characteristics of the valve under different conditions and further optimize the pump and valve. Reciprocating liquid pumps operating under harsh conditions such as low temperature and high pressure generally have more complex pressure-resistant or heat-insulating structures. The inlet and outlet valves, which are usually integrated into the pump body, are also encased in the complex structure of the reciprocating liquid pump, making it difficult to quickly and easily modify or replace the valve structure. Summary of the Invention

[0007] This invention provides a dynamic characteristic testing system for valves of a reciprocating liquid pump. It can use a non-contact eddy current displacement sensor to test the dynamic characteristics of the inlet and outlet valves of the reciprocating liquid pump under harsh conditions of low temperature and high pressure. It also adopts an inlet and outlet valve module that is easy to disassemble and separate from the pump body to achieve rapid replacement of valve components.

[0008] A valve dynamic characteristic test system for a reciprocating liquid pump includes a front high-pressure storage tank, a circulation tank, a reciprocating liquid pump, and a rear high-pressure storage tank.

[0009] The reciprocating liquid pump has an inlet valve module and an outlet valve module detachably fixed at its inlet and outlet ends, respectively. The inlet valve module includes an inlet valve to be tested and a first eddy current displacement sensor for measuring the displacement of the inlet valve core. The outlet valve module includes an outlet valve to be tested and a second eddy current displacement sensor for measuring the displacement of the outlet valve core.

[0010] The outlet of the front high-pressure liquid storage tank is connected to the circulation tank, the outlet of the circulation tank is connected to the inlet valve through a pipeline, and the outlet valve is connected to the rear high-pressure liquid storage tank through a pipeline.

[0011] A pressure gauge is installed before the inlet valve, after the outlet valve, and in the cylinder of the reciprocating liquid pump. The pressure data monitored by the three pressure gauges, the displacement data from the first eddy current displacement sensor and the second eddy current displacement sensor are sent to the display instrument for real-time display and monitoring, and transmitted to the control platform. The control platform is used to record the monitored data and control the motor operation of the reciprocating liquid pump.

[0012] In the technical solution of this invention, the easily disassembled inlet valve module and outlet valve module enable rapid replacement of valve components, thereby adjusting parameters such as valve core structure, spring stiffness, and maximum opening. The eddy current sensor enables non-contact measurement of valve core displacement under low-temperature and high-pressure environments. By adjusting the motor operating parameters of the reciprocating liquid pump, the desired characteristic curve and reciprocating frequency of the reciprocating liquid pump can be output. By changing the pressure of the liquid storage tanks before and after the reciprocating liquid pump, the pressure before the inlet valve and after the outlet valve can be adjusted.

[0013] Furthermore, the reciprocating liquid pump is provided with a pump container and a vacuum jacket in sequence on its exterior.

[0014] The cryogenic liquid in the circulation tank enters the pump container, which is insulated by a vacuum jacket, through the main valve. The cryogenic liquid in the pump container then enters the pump cylinder of the reciprocating liquid pump through the inlet valve module. The reciprocating liquid pump, driven by a motor, pressurizes the cryogenic liquid, which then enters the high-pressure storage tank through the outlet valve in the outlet valve module and the subsequent regulating valve.

[0015] In the pump container, the vapors caused by heat leakage return to the circulation tank through the return port at the top of the inlet valve module and are then vented out.

[0016] In the aforementioned inlet valve module, the inlet valve is threadedly mounted on the reciprocating liquid pump, the first eddy current displacement sensor is clamped and fixed to the upper part of the inlet valve by a flange, and the housing of the inlet valve module is connected to the pump container and the vacuum jacket by a flange.

[0017] In the aforementioned outlet valve module, the housing of the outlet valve module is threaded onto the outlet pipe of the reciprocating liquid pump, and the outlet valve and the second eddy current displacement sensor are clamped and fixed inside the housing of the outlet valve module by a flange.

[0018] Before the valve dynamic characteristic test, the inlet valve and outlet valve to be tested are adjusted to specific structural performance parameters according to the test requirements. Then, the inlet valve module and outlet valve module are installed at the inlet and outlet ends of the reciprocating liquid pump. The structural characteristic parameters include valve core structure, spring stiffness, and maximum opening degree.

[0019] During the valve dynamic characteristic test, the non-contact measurement of the valve core displacement of the inlet and outlet valves under low temperature and high pressure environment is realized by using an eddy current sensor; the required characteristic curve and reciprocating frequency of the reciprocating liquid pump are output by adjusting the motor operating parameters of the reciprocating liquid pump; and the pressure before the inlet valve and after the outlet valve are adjusted by changing the pressure of the front high pressure storage tank and the rear high pressure storage tank.

[0020] Alternatively, the working fluid of the reciprocating liquid pump is a normal temperature or low temperature fluid, and the reciprocating liquid pump can be a piston pump, plunger pump, or diaphragm pump.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. A modular structure that can take into account low temperature insulation, high pressure sealing and convenient replacement and debugging is proposed. The inlet and outlet valves that were originally buried deep in the low temperature pump are extended to a separate valve module. On the one hand, displacement measurement can be realized that was impossible in the original small and cramped pump structure. On the other hand, it facilitates the rapid replacement and debugging of the valve structure.

[0023] 2. The valve dynamic characteristic test system for reciprocating liquid pumps proposed in this invention can measure the dynamic characteristics of the inlet and outlet valves of reciprocating liquid pumps under different inlet and outlet pressures, pump characteristic curves, and pump operating frequencies. It adopts detachable valve modules to quickly replace the inlet and outlet valve components under test, realizing the testing and optimization of the inlet and outlet valves of low temperature and high pressure reciprocating liquid pumps. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of a valve dynamic characteristic testing system for a reciprocating liquid pump according to the present invention.

[0025] Figure 2This is a schematic diagram of the assembly structure of the reciprocating liquid pump and valve module in this invention;

[0026] Figure 3 This is a schematic diagram of the inlet valve module in this invention;

[0027] Figure 4 This is a schematic diagram of the outlet valve module in this invention;

[0028] Figure 5 The following are the motion curves of the inlet valve under different spring stiffnesses in the embodiments of the present invention;

[0029] Figure 6 The figures show the motion curves of the outlet valve under different spring stiffnesses in the embodiments of the present invention.

[0030] Figure 7 The following are the motion curves of the inlet valve under different maximum valve openings in the embodiments of the present invention;

[0031] Figure 8 These are the motion curves of the outlet valve under different maximum valve openings in embodiments of the present invention;

[0032] Figure 9 This illustrates the movement of the inlet valve at different piston frequencies in embodiments of the present invention.

[0033] Figure 10 This illustrates the movement of the outlet valve at different piston frequencies in embodiments of the present invention. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and do not constitute any limitation thereof.

[0035] like Figure 1 and Figure 2 As shown, a valve dynamic characteristic testing system for a reciprocating liquid pump includes: a front high-pressure storage tank 1, a regulating valve 2, a storage tank pressure gauge 3, a circulation tank 4, a main valve 5, a pump container 6, an inlet valve 7, a first eddy current displacement sensor 8, a pump cylinder pressure gauge 9, a reciprocating liquid pump 10, a vacuum jacket 11, a motor 12, an outlet valve 13, a second eddy current displacement sensor 14, a safety valve 15, a storage tank pressure gauge 16, a regulating valve 17, a rear high-pressure storage tank 18, a display instrument 19, a control platform 20, a piston 21, an inlet valve module 22, and an outlet valve module 23.

[0036] The front high-pressure storage tank 1 is used to supply the circulation tank 4 and maintain its liquid level; one end of the reciprocating liquid pump 10 is connected to the inlet valve module 22 and draws liquid from the circulation tank 4, and the other end is connected to the outlet valve module 23 and discharges liquid to another rear high-pressure storage tank 18; the first eddy current displacement sensor 8 is installed in the inlet valve module 22, and the second eddy current displacement sensor 14 is installed in the outlet valve module 23, which are used to measure the valve core displacement without contact under low temperature and high pressure conditions; the pressure sensor is used to measure the pressure status of the two storage tanks and the cylinder pressure of the reciprocating liquid pump 10; the control platform is responsible for recording the measurement data and controlling the operation of the motor 12 of the reciprocating liquid pump 10.

[0037] In the valve dynamic characteristic test, the cryogenic liquid in the circulation tank 4 enters the pump container 6, which is insulated by the vacuum jacket 11, through the main valve 5. The upper part of the pump container 6 is connected to the inlet valve module 22, and the lower part is connected to the outlet valve module 23. The vapors caused by heat leakage return to the circulation tank 4 through the return port at the top of the inlet valve module 22 for unified venting. The cryogenic liquid in the pump container 6 enters the pump cylinder of the reciprocating liquid pump 10 through the inlet valve 7 in the inlet valve module 22. The reciprocating liquid pump 10, driven by the motor 12, pressurizes the cryogenic liquid, and then enters the high-pressure storage tank 18 through the outlet valve 13 in the outlet valve module 23 and the subsequent regulating valve 17. The valve core displacement of the inlet valve 7 and the outlet valve 13 is measured by the first eddy current displacement sensor 8 and the second eddy current displacement sensor 14, respectively. The pressure before inlet valve 7 is measured by pressure gauge 3 in the storage tank. The pressure after inlet valve 7 and before outlet valve 13 is measured by pressure gauge 9 in the pump cylinder. The pressure after outlet valve 13 is measured by pressure gauge 16 in the storage tank. The measured data are input to the control platform 20 for processing and recording via display instrument 19.

[0038] To facilitate experiments on inlet valve 7 and outlet valve 13 with different structural performance parameters, a modular inlet / outlet valve structure that is easy to disassemble was adopted. The structure of inlet valve module 22 is as follows: Figure 3 As shown, the system includes an inlet valve 7 threaded onto a reciprocating liquid pump 10, a first eddy current displacement sensor 8 clamped to the upper part of the inlet valve 7 via a flange, and a housing connected to the pump container 6 and the vacuum jacket 11 via a flange. The outlet valve module 23 has the following structure. Figure 4 As shown, it includes a pressure-resistant housing that is threadedly mounted on the outlet pipe of a reciprocating liquid pump 10, an outlet valve 13 that is clamped and fixed inside the pressure-resistant housing by a flange, and a second eddy current displacement sensor 14.

[0039] In practical applications, the working fluid of the reciprocating liquid pump 10 is a normal temperature or low temperature fluid, and its structure can be a piston pump, plunger pump or diaphragm pump.

[0040] When a reciprocating liquid pump is a piston pump, it includes a compression cylinder, an inlet valve, an outlet valve, and a piston. The reciprocating motion of the piston causes the pump chamber volume to change periodically, thereby achieving pressurized delivery of the liquid.

[0041] When the reciprocating liquid pump is a plunger pump, it includes a compression cylinder, an inlet valve, an outlet valve, and a plunger. The reciprocating motion of the plunger causes the pump chamber volume to change periodically, thereby achieving pressurized delivery of the liquid.

[0042] When the reciprocating liquid pump is a diaphragm pump, it includes a compression cylinder, an inlet valve, an outlet valve, a piston, hydraulic oil, and a diaphragm. The hydraulic fluid transmits pressure from the piston to the diaphragm, and then to the pressurized liquid, thereby achieving pressurized liquid delivery.

[0043] To verify the effectiveness of the present invention, typical measurement results of valve dynamic characteristic tests of a reciprocating liquid piston pump are presented and analyzed. Figure 5 and Figure 6 The figures show the motion curves of the inlet and outlet valves under different spring stiffnesses. Insufficient spring stiffness will cause the valve to close late and cause backflow of liquid downstream of the valve; excessive spring stiffness will cause the valve to close prematurely and rebound on the valve seat, increasing valve oscillation and wear due to valve collision. Figure 7 and Figure 8 The figures show the motion curves of the inlet and outlet valves at different maximum valve openings. Too small a valve opening will increase valve resistance, while too large a valve opening will lead to untimely closure, liquid backflow, and a greater collision speed. Figure 9 and Figure 10 The motion of the inlet and outlet valves at different piston frequencies is shown. For a reciprocating liquid pump with an operating frequency of 2Hz, when the operating frequency decreases, the motion curves of the inlet and outlet valves will oscillate. Long-term operation under low-frequency conditions will lead to unstable operation and increased valve collision wear.

[0044] Therefore, for reciprocating liquid pumps operating under different conditions such as operating frequency, fluid properties, and upstream and downstream pressures, valve parameters need to be optimized to match the valve parameters with actual operating requirements, enhance valve motion stability, and reduce valve resistance, oscillation, and wear. Furthermore, under the same operating conditions, differences in valve structure can lead to variations in motion curves and valve performance. Modular inlet and outlet valve structures that are easy to disassemble facilitate rapid adjustment of valve parameters and replacement of valve structures, improve pump and valve performance, and support pump and valve design.

[0045] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A valve dynamic characteristic testing system for a reciprocating liquid pump, characterized in that, It includes a front high-pressure liquid storage tank (1), a circulation tank (4), a reciprocating liquid pump (10), and a rear high-pressure liquid storage tank (18). The inlet end and outlet end of the reciprocating liquid pump (10) are respectively detachably fixed with an inlet valve module (22) and an outlet valve module (23); the inlet valve module (22) includes an inlet valve (7) to be tested and a first eddy current displacement sensor (8) for measuring the valve core displacement of the inlet valve (7); the outlet valve module (23) includes an outlet valve (13) to be tested and a second eddy current displacement sensor (14) for measuring the valve core displacement of the outlet valve (13). In the inlet valve module (22), the inlet valve (7) is threaded onto the reciprocating liquid pump (10), the first eddy current displacement sensor (8) is clamped and fixed to the upper part of the inlet valve (7) by a flange, and the housing of the inlet valve module (22) is connected to the pump container (6) and the vacuum jacket (11) by a flange. In the outlet valve module (23), the housing of the outlet valve module (23) is installed on the outlet pipe of the reciprocating liquid pump (10) by threads, and the outlet valve (13) and the second eddy current displacement sensor (14) are fixed inside the housing of the outlet valve module (23) by flange clamping. During the valve dynamic characteristic test, the non-contact measurement of the valve core displacement of the inlet valve (7) and outlet valve (13) under low temperature and high pressure environment is realized by using an eddy current sensor; The outlet of the front high-pressure storage tank (1) is connected to the circulation tank (4), the outlet of the circulation tank (4) is connected to the inlet valve (7) through a pipeline, and the outlet valve (13) is connected to the rear high-pressure storage tank (18) through a pipeline. A pressure gauge is provided in front of the inlet valve (7), after the outlet valve (13), and in the cylinder of the reciprocating liquid pump (10). The pressure data monitored by the three pressure gauges, the displacement data of the first eddy current displacement sensor (8) and the second eddy current displacement sensor (14) are sent to the display instrument (19) for real-time display and monitoring, and transmitted to the control platform (20). The control platform (20) is used to record the monitored data and control the motor operation of the reciprocating liquid pump (10).

2. The valve dynamic characteristic test system for a reciprocating liquid pump according to claim 1, characterized in that, The reciprocating liquid pump (10) is provided with a pump container (6) and a vacuum jacket (11) in sequence on the outside. The cryogenic liquid in the circulation tank (4) enters the pump container (6) insulated by the vacuum jacket (11) through the main valve (5). The cryogenic liquid in the pump container (6) enters the pump cylinder of the reciprocating liquid pump (10) through the inlet valve (7) in the inlet valve module (22). The reciprocating liquid pump (10) driven by the motor (12) pressurizes the cryogenic liquid, and then enters the high-pressure storage tank (18) through the outlet valve (13) in the outlet valve module (23) and the regulating valve (17) thereafter.

3. The valve dynamic characteristic test system for a reciprocating liquid pump according to claim 1, characterized in that, In the pump container (6), the evaporation gas caused by heat leakage returns to the circulation tank (4) through the return port at the top of the inlet valve module (22) and is discharged uniformly.

4. The valve dynamic characteristic test system for a reciprocating liquid pump according to claim 1, characterized in that, Before the valve dynamic characteristic test, the inlet valve (7) and outlet valve (13) to be tested are adjusted to specific structural performance parameters according to the test requirements. Then, the inlet valve module (22) and outlet valve module (23) are installed on the inlet and outlet ends of the reciprocating liquid pump (10). The structural characteristic parameters include valve core structure, spring stiffness, and maximum opening.

5. The valve dynamic characteristic test system for a reciprocating liquid pump according to claim 4, characterized in that, During the valve dynamic characteristic test, the required characteristic curve and reciprocating frequency of the reciprocating liquid pump (10) are output by adjusting the motor operating parameters of the reciprocating liquid pump (10); the pressure before the inlet valve (7) and the pressure after the outlet valve (13) are adjusted by changing the pressure of the front high pressure storage tank (1) and the rear high pressure storage tank (18).

6. The valve dynamic characteristic test system for a reciprocating liquid pump according to claim 1, characterized in that, The working fluid of the reciprocating liquid pump (10) is a normal temperature or low temperature fluid, and the reciprocating liquid pump (10) is a piston pump, plunger pump or diaphragm pump.

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