A pressurized damping large-flow cavitation test device

Abstract

The application discloses a pressurized damping large-flow cavitation test device, and belongs to the field of thermal hydraulic test.The test device comprises a pressurized pump group, a pulse damper, a flexible connecting pipe, at least one test loop and a main loop pipeline.The pressurized pump group is connected with the test loop on the main loop pipeline to form a loop to make test water circulate; the pressurized pump group comprises a series connection of a first-stage pressurized pump and a second-stage pressurized pump group, the second-stage pressurized pump group further comprises at least two second-stage pressurized pumps in parallel, and a straight pipe section at an outlet of the second-stage pressurized pump is at least partially arranged as the flexible connecting pipe; the pulse damper is arranged on the main loop pipeline downstream of the pressurized pump group to absorb pressure pulses; and a cavitation test piece is arranged in the test loop.The device can improve the test flow to 2000m 3 / h level through the stage pressurized pump group sharing the lift and the second-stage pressurized pump group in parallel sharing the high-pressure flow; and the flexible connecting pipe and the pulse damper can fully absorb pipeline vibration and reduce the interference on cavitation test data.

Description

Technical Field

[0001] This invention belongs to the field of thermal hydraulic testing, specifically relating to a pressurized, vibration-damped, high-flow-rate cavitation test device. Background Technology

[0002] Cavitation refers to the phenomenon where a liquid vaporizes to form cavitation bubbles when the local pressure drops to the saturated vapor pressure at that temperature, and then collapses at the pressure recovery point. Cavitation can cause performance degradation, increased vibration and noise, and erosion of flow surfaces in hydraulic machinery such as pumps, turbines, and valves. Therefore, cavitation performance testing is a crucial step in the research and development and acceptance of related equipment. In equipment such as nuclear power units, the high flow rate and high operating temperature necessitate specialized cavitation performance testing under high flow conditions. However, existing high-flow-rate cavitation test benches mostly use single-stage centrifugal pumps directly driving closed-loop circuits. A single pump cannot simultaneously meet the requirements of high flow rate and high head. If a pump set is used, vibration can easily interfere with the test section, and pressure pulsation can lead to large measurement errors and poor repeatability. Therefore, providing a pressure-boosting and vibration-damping high-flow-rate cavitation test device is of significant importance for improving the accuracy of cavitation tests under high flow conditions. Summary of the Invention

[0003] The purpose of this invention is to provide a pressure-boosting and vibration-damping high-flow-rate cavitation test device to improve the accuracy of cavitation tests under high-flow-rate conditions.

[0004] According to an embodiment of the present invention, a high-flow-rate cavitation test apparatus with pressurization and vibration reduction is provided. The apparatus includes: a booster pump set, a pulse damper, a flexible connecting pipe, at least one test circuit, and a main circuit pipeline. The booster pump set is connected to the test circuit on the main circuit pipeline to allow test water to circulate between the booster pump set and the test circuit. The booster pump set includes a primary booster pump and a secondary booster pump set. The secondary booster pump set includes at least two secondary booster pumps connected in parallel, and is located downstream of the primary booster pump. At least a portion of the outlet straight pipe section of the secondary booster pump is configured as the flexible connecting pipe. The pulse damper is located on the main circuit pipeline downstream of the booster pump set to allow the pulse damper to absorb pressure pulsations from the booster pump set. A cavitation test specimen is installed in the test circuit.

[0005] The experimental setup employs a series-connected primary and secondary booster pump group, with the head shared by both stages. The flow rate of the secondary booster pump group is provided by the parallel-connected secondary booster pump groups, enabling it to provide 2000m³ / h based on existing mature models. 3The high flow rate of [number] h expands the coverage of test conditions. Simultaneously, the vibration of the secondary booster pump unit is isolated through a flexible connecting pipe, preventing pump vibration from interfering with the acquisition of cavitation test data; a pulse damper is used to absorb pump outlet pressure pulsations and smooth out hydraulic oscillations in the circuit, further improving the accuracy and repeatability of the cavitation test.

[0006] Furthermore, in some embodiments, the primary booster pump is a horizontal centrifugal pump.

[0007] Furthermore, in some embodiments, at least a portion of the inlet straight pipe section of the secondary booster pump is configured as the flexible connecting pipe.

[0008] Furthermore, in some embodiments, the pulse damper is an airbag-type pulse damper.

[0009] Furthermore, in some embodiments, a heating circuit and a cooling circuit connected in parallel to the main circuit pipe downstream of the pulse damper are provided.

[0010] Furthermore, in some embodiments, the heating circuit is connected in parallel with a portion of the main circuit pipe; the cooling circuit is disposed on a cooling branch pipe connected in parallel with the test circuit, and the cooling circuit is connected in parallel with a portion of the cooling branch pipe.

[0011] Furthermore, in some embodiments, the cavitation test specimen is equipped with an overpressure emission system.

[0012] Furthermore, in some embodiments, the test circuit is configured as at least two circuits, wherein at least one test circuit has an outlet pressure regulating valve at its outlet, the outlet of which is connected to an open water tank, and the outlet of the open water tank is connected to the main circuit pipeline; the outlets of the remaining test circuits are equipped with closed-loop return valves, and are connected to the main circuit pipeline through the closed-loop return valves.

[0013] Furthermore, in some embodiments, the test apparatus further includes a water filling system, which includes a water filling tank, a water filling pump, and a water filling valve; the water filling tank is connected to the main circuit pipeline upstream of the primary booster pump via the water filling pump and the water filling valve, and is used to inject water and pressurize the main circuit pipeline.

[0014] Furthermore, in some embodiments, the test apparatus further includes a parameter measurement system, which includes a pressure sensor, a temperature sensor, and a flow meter. The parameter measurement system measures at least the temperature, pressure, and flow rate in the main loop pipe upstream of the test loop.

[0015] Furthermore, in some embodiments, the test apparatus also includes a measurement and control system, which is signal-connected to the parameter measurement system and is capable of controlling the rotational speed of the booster pump group and the opening degree of at least some valves in the booster vibration reduction high-flow cavitation test apparatus. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a high-flow-rate cavitation test device with pressurization and vibration reduction in one embodiment.

[0017] Meaning of the reference numerals in the attached figures: 1-First-stage booster pump; 2-Second-stage booster pump; 3-Flexible connecting pipe; 4-Pulse damper; 5-Heating circuit; 6-Pressure and temperature measurement point; 7-Main valve; 8-Main circuit flow meter; 9-First test circuit; 10-Second test circuit; 11-Third test circuit; 12-Overpressure discharge system; 13-Outlet pressure regulating valve; 14-Closed-loop return water valve; 15-Cooling circuit; 16-Pump inlet temperature and pressure measurement point; 17-Pump inlet vent valve; 18-Charging valve; 19-Return water valve; 20-Charging pump; 21-Measurement and control system; 22-Charging water tank; 23-Open water tank; 24-First test piece; 25-Second test piece; 26-Third test piece; 27-Cooling circuit branch pipe; 28-Pressure measurement point.

[0018] The purpose of the above-described drawings is to provide a detailed description of the present invention so that those skilled in the art can understand the technical concept of the invention, and is not intended to limit the invention. For the sake of brevity, the above-described drawings only schematically depict the structures related to the technical features of the present invention, and do not depict the complete structure and all details strictly according to actual scale. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0020] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment herein. The phrase appearing in various places in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive, independent, or alternative embodiments. Those skilled in the art will understand that the embodiments herein can be combined with other embodiments without causing structural conflicts.

[0021] In this description, unless otherwise explicitly specified and limited, the technical terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to the connection of mechanical structures, the relationship of signal connection, or the fixing and assembly of physical structures. They can be movable connections, fixed connections, or integral parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0022] In this description, terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating relative importance or limiting the number, specific order, or primary / secondary relationship of the described technical features. In this description, "multiple" means at least two.

[0023] In high-temperature, high-pressure pipelines containing liquid, when the pressure drops to the saturated vapor pressure at the current temperature, some of the liquid in the pipeline will vaporize, forming cavitation bubbles. These bubbles will then collapse and disappear when they travel through the pipeline to a high-pressure region above the saturated vapor pressure. Cavitation causes significant vibration and noise, and the resulting pressure fluctuations and water hammer effects can degrade pipeline and equipment performance, leading to seal failure and leakage risks, and also exacerbating erosion of flow surfaces. Therefore, cavitation performance testing is a crucial part of the acceptance testing of hydraulic machinery such as pumps, turbines, and valves. Cavitation performance testing is particularly important for pipeline equipment with high flow rates, high pressures, and high operating temperatures. However, existing cavitation test benches generally use a single-stage centrifugal pump directly driven closed-loop circuit, and the test flow rate and head are severely limited by the performance of the single pump, typically around 2000m. 3 High-flow-rate conditions are difficult to cover; at the same time, the mechanical vibration of the high-flow-rate pump set during operation will interfere with the cavitation state and signal measurement when transmitted to the test section; furthermore, the superposition of pump outlet pressure pulsation and loop hydraulic oscillation will cause significant pressure fluctuations in the test section, which will increase the measurement error of key parameters such as cavitation number and result in poor test repeatability.

[0024] To address the aforementioned problems in the prior art, embodiments of the present invention provide a high-flow-rate cavitation test device with pressurization and vibration reduction, which can effectively eliminate the interference of pump vibration and pressure fluctuations on the test results while providing a high flow rate for the cavitation test, thereby improving the accuracy and repeatability of the cavitation test.

[0025] In a preferred embodiment, the structure of the test apparatus is as follows: Figure 1 As shown, the system includes a booster pump set, a pulse damper 4, a flexible connecting pipe 3, a test circuit, and a main circuit pipeline. The booster pump set is connected to the test circuit on the main circuit pipeline. The test water is transported by the booster pump set to the downstream main circuit pipeline, flows through the test circuit, and then flows back to the booster pump set through the downstream main circuit pipeline, thus achieving a circulating flow.

[0026] Specifically, the booster pump set includes a primary booster pump 1 and a secondary booster pump set consisting of two parallel secondary booster pumps 2. The outlet of the primary booster pump 1 is connected to the inlet of the parallel secondary booster pump set, and the outlets of the two secondary booster pumps 2 are connected in parallel to the main circuit pipeline. In a preferred embodiment, the primary booster pump 1 can be a horizontal centrifugal pump. A pump inlet exhaust valve 17 is installed at the high point of the pipeline upstream of the primary booster pump 1 to discharge gas mixed in the pipeline and prevent gas from entering the booster pump set. At least part of the straight outlet pipe section of the two secondary booster pumps 2 uses a flexible connecting pipe 3 to absorb the vibration of the secondary booster pumps 2 and prevent it from being transmitted to the main circuit pipeline. Because the booster pump set adopts a series structure of a primary booster pump 1 and a secondary booster pump set, the head is shared by the two pump sets. Both the primary booster pump 1 and the secondary booster pump 2 can operate within their high-efficiency range, reducing equipment pressure and vibration, and facilitating equipment selection. The secondary booster pump set uses a parallel design of two secondary booster pumps 2, with the high-pressure flow provided jointly by the two secondary booster pumps 2, reducing the burden on the secondary booster pumps 2. At the same time, the high-pressure flexible connecting pipe 3 can effectively shield the vibration of the secondary booster pumps 2, preventing the vibration of the secondary booster pumps 2 operating under high pressure from interfering with the test circuit. In a further preferred embodiment, at least part of the inlet straight pipe section of the secondary booster pump 2 also uses the flexible connecting pipe 3 to prevent the vibration between the primary booster pump 1 and the secondary booster pump 2 from affecting each other. In other embodiments, the secondary booster pump set can also use three or more secondary booster pumps 2 connected in parallel, and the specific number can be adaptively selected according to the performance parameters of the secondary booster pumps 2 and the test conditions. In some embodiments, the flexible connecting pipe 3 can be a pressure-resistant corrugated pipe.

[0027] A pulse damper 4 is connected to the main circuit pipeline downstream of the booster pump set. The pulse damper 4 is used to absorb the pressure pulsation at the pump outlet, smooth the hydraulic oscillation in the water circuit, ensure the stability of downstream flow and pressure, and improve the measurement accuracy of cavitation data and the repeatability of test results. In a preferred embodiment, the pulse damper 4 is an airbag-type pulse damper.

[0028] In a preferred embodiment, three test circuits are provided: a first test circuit 9, a second test circuit 10, and a third test circuit 11 connected in parallel. A first test piece 24 is provided in the first test circuit 9, a second test piece 25 is provided in the second test circuit 10, and a third test piece 26 is provided in the third test circuit 11, allowing simultaneous cavitation tests on all three test pieces. In other embodiments, one, two, or more test circuits may be provided. In a preferred embodiment, each test piece is equipped with an overpressure relief system 12, which automatically releases pressure when the test circuit containing the test piece experiences overpressure. In different embodiments, the overpressure relief system 12 may be configured as a pressure relief valve or a rupture disc. Each test circuit is equipped with an independent pressure sensor, temperature sensor, and flow meter for accurate monitoring of test conditions.

[0029] In a preferred embodiment, an outlet pressure regulating valve 13 is provided at the outlet of the first test loop 9. The outlet of the outlet pressure regulating valve 13 is connected to an open water tank 23 to allow adjustment of the back pressure of the first test loop 9. A pressure measuring point 28 is provided upstream of the outlet pressure regulating valve 13 for measuring the back pressure of the first test loop 9. By adjusting the opening of the outlet pressure regulating valve 13, the back pressure of the first test piece 24 under test conditions can be adjusted between atmospheric pressure and high pressure. The outlet of the open water tank 23 is connected to the main loop pipeline to allow the test water of the first test loop to flow into the open water tank 23 through the outlet pressure regulating valve 13 and then return to the main loop pipeline. A closed loop return water valve 14 is provided at the outlet of the second test loop 10 and the third test loop 11. The outlet of the closed loop return water valve 14 is connected to the main loop pipeline to allow the test water in the second test loop 10 and the third test loop 11 to return to the main loop pipeline through the closed loop return water valve 14. The first test loop 9, the second test loop 10, and the third test loop 11 are each independently controlled, enabling switching between single-channel and multi-channel parallel testing. The second test loop 10 and the third test loop 11 can be configured to use flow meters with different ranges to conduct tests under different flow conditions, thereby improving the accuracy of flow meter measurements.

[0030] A heating circuit 5 is installed on the main circuit pipeline downstream of the pulse damper 4 and upstream of the test circuit. The heating circuit 5 is equipped with a heating device to heat the test water to the preset temperature required for the test. In a preferred embodiment, the heating circuit 5 is connected in parallel with a part of the main circuit pipeline. Since the flow rate is very large under test conditions, a heat exchanger connected in series with the main circuit pipeline would create a high resistance. Therefore, the heating circuit 5 heats the test water by connecting it in parallel with a part of the main circuit pipeline.

[0031] A cooling circuit 15 is connected in parallel with the test circuit to cool the test water. The cooling circuit 15 is located on a branch pipe 27 of the cooling circuit, which is connected in parallel with the test circuit. The test water output from the booster pump can flow back upstream of the booster pump via the branch pipe 27 to continue circulating. In a preferred embodiment, a portion of the cooling circuit 15 and the branch pipe 27 are connected in parallel. This prevents the cooling circuit 15 from being connected in series in the main channel of the test water, thus avoiding excessive resistance.

[0032] It is easy to understand that, in the preferred embodiment, both the heating circuit 5 and the cooling circuit 15 only heat or cool a portion of the test water in the main circuit pipeline. The temperature of the test water is controlled by injecting the heated or cooled test water back into the main circuit pipeline and mixing it with the remaining test water, in order to avoid 2000m 3 Under high flow rate conditions at the / h level, excessive resistance is generated in the flow channel.

[0033] In some preferred embodiments, the test apparatus further includes a top-fill water system, which includes a top-fill water tank 22 and a top-fill valve 18. The top-fill water tank 22 is connected to the main circuit pipeline upstream of the inlet of the first-stage booster pump 1 via the top-fill valve. The top-fill water tank 22 stores test water and can be filled with water from an external water source, thus replenishing the main circuit pipeline. A return water valve 19 and a top-fill pump 20 are connected in parallel between the top-fill water tank 22 and the top-fill valve 18. The top-fill pump 20 is used to pump the test water out of the top-fill water tank. One end of the branch where the return water valve 19 is located is connected downstream of the top-fill pump 20, and the other end is connected to the top-fill water tank 22, so that some of the test water pumped out by the top-fill pump 20 can flow back to the top-fill water tank 22 through the return water valve 19. In this way, by controlling the opening of the top-fill valve 18 and the return water valve 19, the replenishment flow rate to the main circuit pipeline can be controlled while maintaining a high flow rate of the top-fill pump.

[0034] In a preferred embodiment, the test apparatus further includes a parameter measurement system, which includes a pressure sensor, a temperature sensor, and a flow meter. A pressure and temperature measurement point 6 is installed on the main circuit pipeline downstream of the heating circuit 5 to measure the temperature and pressure of the test water in the main circuit. A main circuit flow meter 8 is installed downstream of the main valve 7 in the main circuit pipeline to measure the total flow rate of the test water in the main circuit. Each test circuit is equipped with a pressure sensor, a temperature sensor, and a flow meter to measure the pressure, temperature, and flow rate of the test circuit separately. An inlet temperature and pressure measurement point 16 is also installed upstream of the first-stage booster pump 1, where the pressure and temperature sensors are used to measure the temperature and pressure parameters of the test water at the inlet of the first-stage booster pump 1. In a preferred embodiment, the heating circuit 5 and the cooling circuit 15 are also equipped with pressure sensors, temperature sensors, and flow meters, respectively. In a further preferred embodiment, the test apparatus also includes a measurement and control system 21, which is connected to the parameter measurement system and can collect data measured by various sensors and flow meters. Simultaneously, the measurement and control system 21 is also connected to the pump group and at least some valves in the test apparatus, and can control the pump group's speed and adjust the valve opening based on the measurement results of the parameter measurement system. In one specific embodiment, the measurement and control system 21 can control the speed of the charging pump 20 and the booster pump group, as well as the opening of the main valve 7, the outlet pressure regulating valve 13, the return water valve 19, and the charging valve 18, thereby controlling the back pressure test conditions of the first test piece 24 and the flow rate of the charging water system replenishing water to the main circuit pipeline according to the pressure parameters measured at different locations. In other preferred embodiments, the measurement and control system 21 can also automatically adjust the flow rate and heating or cooling power of the heating circuit 5 and the cooling circuit 15, thereby achieving accurate adjustment of the test water temperature.

[0035] The pressurized, vibration-damping, high-flow-rate cavitation test apparatus provided in the above embodiments can provide 2000m 3 The device provides high-flow-rate testing conditions at the / h level, fully covering the requirements of complex testing scenarios. It effectively isolates mechanical vibrations generated by the pump unit and absorbs pump outlet pressure pulsations and loop hydraulic oscillations, reducing interference with cavitation test measurement results and improving the accuracy and repeatability of test data. The device's multi-parallel test loop design also enables simultaneous testing under different operating conditions, improving testing efficiency. It is safe, reliable, and easy to maintain.

[0036] The purpose of the above embodiments is to provide a further detailed description of the present invention in conjunction with the accompanying drawings, so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the present invention, optimization or equivalent substitution of the technical features involved, as well as combination of implementation methods in different embodiments without causing structural and principle conflicts, all fall within the protection scope of the present invention.

Claims

1. A high-flow-rate cavitation test device with pressurization and vibration reduction, characterized in that, include: The system includes a booster pump set, a pulse damper, a flexible connecting pipe, at least one test circuit, and a main circuit pipeline; the booster pump set and the test circuit are connected to the main circuit pipeline to allow test water to circulate between the booster pump set and the test circuit. The booster pump set includes a primary booster pump and a secondary booster pump set. The secondary booster pump set includes at least two secondary booster pumps connected in parallel. The secondary booster pump set is located downstream of the primary booster pump. The outlet straight pipe section of the secondary booster pump is at least partially configured as the flexible connecting pipe; The pulse damper is installed on the main circuit pipeline downstream of the booster pump group to allow the pulse damper to absorb the pressure pulsation of the booster pump group. A cavitation test element is installed in the test circuit.

2. The pressurized, vibration-damping, high-flow-rate cavitation test apparatus according to claim 1, characterized in that, The primary booster pump is a horizontal centrifugal pump.

3. The apparatus according to claim 1 or 2, characterized in that, At least a portion of the inlet straight pipe section of the secondary booster pump is configured as the flexible connecting pipe.

4. The pressurized, vibration-damping, high-flow-rate cavitation test apparatus according to claim 1 or 2, characterized in that, The pulse damper is an airbag-type pulse damper.

5. The pressurized, vibration-damping, high-flow-rate cavitation test apparatus according to claim 1, characterized in that, The main circuit pipeline downstream of the pulse damper is equipped with a heating circuit and a cooling circuit connected in parallel with the test circuit.

6. The pressurized, vibration-damping, high-flow-rate cavitation test apparatus according to claim 5, characterized in that, The heating circuit is connected in parallel with a portion of the main circuit pipeline; the cooling circuit is installed on a cooling branch pipe connected in parallel with the test circuit, and the cooling circuit is connected in parallel with a portion of the cooling branch pipe.

7. The pressurized, vibration-damping, high-flow-rate cavitation test apparatus according to claim 1, characterized in that, The cavitation test specimen is equipped with an overpressure emission system.

8. The pressurized, vibration-damping, high-flow-rate cavitation test apparatus according to claim 1, characterized in that, The test circuit is configured with at least two circuits, wherein at least one test circuit has an outlet pressure regulating valve at its outlet, the outlet of which is connected to an open water tank, and the outlet of the open water tank is connected to the main circuit pipeline; the outlets of the remaining test circuits are equipped with closed-loop return valves, and are connected to the main circuit pipeline through the closed-loop return valves.

9. The pressurized, vibration-damping, high-flow-rate cavitation test apparatus according to claim 1, characterized in that, It also includes a water filling system, which includes a water filling tank, a water filling pump, and a water filling valve; the water filling tank is connected to the main circuit pipeline upstream of the first-stage booster pump via the water filling pump and the water filling valve, and is used to inject water and replenish pressure into the main circuit pipeline.

10. The pressurized, vibration-damping, high-flow-rate cavitation test apparatus according to claim 1, characterized in that, It also includes a parameter measurement system, which includes a pressure sensor, a temperature sensor, and a flow meter. The parameter measurement system measures at least the temperature, pressure, and flow rate in the main circuit pipeline upstream of the test circuit.

11. The pressurized, vibration-damping, high-flow-rate cavitation test apparatus according to claim 10, characterized in that, It also includes a measurement and control system, which is connected to the parameter measurement system and can control the speed of the booster pump group and the opening degree of at least some valves in the booster and vibration reduction high-flow cavitation test device.

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