Circulating tank system and method for testing performance of cryopump

Abstract

The invention discloses a circulation tank system and method for low-temperature pump performance testing, and the system comprises a circulation tank, a circulation tank pressurization pry, a boil-off gas recovery pipeline, an emptying discharge pipeline, a top liquid inlet pipeline and a bottom liquid inlet pipeline, a storage tank is communicated to the upper end of the circulation tank through the top liquid inlet pipeline, and is communicated to the lower end of the circulation tank through the bottom liquid inlet pipeline; the circulating tank is communicated with the testing pump pool through a testing medium liquid outlet pipeline, the testing pump pool is communicated with the circulating tank through a testing medium backflow pipeline, circulation and storage of a testing medium in the testing process of the low-temperature pump are achieved, and the top of the circulating tank is provided with a boil-off gas recycling pipeline and connected to the storage tank to recycle generated liquefied gas. According to the circulation tank system for testing the performance of the low-temperature pump, by arranging the flash steam recovery pipeline and the diffusion system, consumption of a low-temperature medium is reduced, no hazardous gas is discharged to the outside, waste of the low-temperature medium is reduced, and green, low-carbon and environment-friendly effects are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of cryogenic pump testing, and particularly to a circulation tank system and method for testing the performance of cryogenic pumps. Background Art

[0002] Liquefied natural gas has become a rapidly developing new industry in the energy field with an annual demand growth rate of over 15%. A large number of LNG receiving stations, LNG plants, and LNG storage stations have been established everywhere, which are important measures to optimize the energy structure, relieve the pressure of energy supply, and achieve sustainable and coordinated development of society and the environment. During the production, transportation, reception, and utilization of these cryogenic media, cryogenic submersible pumps are required for the transfer of liquefied natural gas. According to domestic and international standards, cryogenic submersible pumps in cryogenic medium receiving stations must be tested and verified in a cryogenic medium environment. Therefore, cryogenic pump test systems for different cryogenic media have become an indispensable and important test verification link in the research and development process of cryogenic submersible pumps. Based on the rapid development of liquefied natural gas, the strategic development of clean energy, and safe and efficient operation, cryogenic pumps for transporting different cryogenic media have been developed. In the cryogenic pump test system, the circulation and storage of test media are of great significance for the test verification of cryogenic pumps. However, the existing technology has a single structure, unable to perform the performance test of cryogenic pumps with multiple cryogenic media, and there is a large amount of test media waste during the test process. Summary of the Invention

[0003] In view of the above deficiencies existing in the current technical field of cryogenic pump testing, the present invention provides a circulation tank system and method for testing the performance of cryogenic pumps, which can realize the circulation and storage of test media during the cryogenic pump test process.

[0004] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0005] A circulation tank system for testing the performance of cryogenic pumps includes a circulation tank. The circulation tank system for testing the performance of cryogenic pumps is connected to a storage tank and a test pump pool. The storage tank is connected to the upper end of the circulation tank through a top liquid inlet pipeline and to the lower end of the circulation tank through a bottom liquid inlet pipeline. The circulation tank is connected to the test pump pool through a test medium outlet pipeline. The test pump pool is connected to the circulation tank through a test medium return pipeline to realize the circulation and storage of test media during the cryogenic pump test process. It is characterized in that an evaporation gas recovery pipeline is provided at the top of the circulation tank and connected to the storage tank. At the same time, the circulation tank system for testing the performance of cryogenic pumps further includes a relief system connected to the circulation tank through a vent discharge pipeline. The evaporation gas recovery pipeline and the relief system are used to recover or discharge different liquefied gases generated. When the circulation tank is a hot tank, the storage tank injects liquid into the circulation tank through the bottom liquid inlet pipeline; when the circulation tank is a cold tank, the storage tank injects liquid into the circulation tank through the top liquid inlet pipeline.

[0006] According to one aspect of the present invention, the venting system is a flash vapor venting tower. When the medium in the circulation tank is liquid nitrogen, the generated liquid nitrogen flash vapor is introduced into the flash vapor venting tower through the vent discharge pipeline for discharging, so as to keep the pressure inside the circulation tank stable.

[0007] According to one aspect of the present invention, a regulating valve is provided on the vent discharge pipeline, and the regulating valve is used to automatically control the connection and closing of the flash vapor venting tower.

[0008] According to one aspect of the present invention, a circulation tank booster skid is connected between the circulation tank and the bottom liquid inlet pipeline. The circulation tank booster skid is used to increase and stabilize the pressure of the circulation tank, so that the test medium can smoothly enter the test pump pool from the circulation tank.

[0009] According to one aspect of the present invention, a regulating valve is provided on the circulation tank booster skid, and the regulating valve is used to control the connection and closing of the circulation tank booster skid.

[0010] According to one aspect of the present invention, reinforcing rings are segmentally arranged on the outer wall of the circulation tank, and the number of the reinforcing rings is at least five.

[0011] According to one aspect of the present invention, the type of the circulation tank is vertical, the designed volume is 100 m 3 , and the designed temperature of the circulation tank is -196°C.

[0012] According to one aspect of the present invention, a pressure transmitter and a liquid level transmitter are arranged on the side of the circulation tank, and are used to measure and monitor the pressure magnitude and liquid level height inside the circulation tank.

[0013] According to one aspect of the present invention, when the test medium is liquefied natural gas, evaporation gas is generated during the test in the circulation tank, and the evaporation gas is recovered back to the storage tank through the evaporation gas recovery pipeline at the top of the circulation tank.

[0014] A test method for a circulation tank for low-temperature pump performance testing includes the following steps:

[0015] Set up a circulation tank for adding liquid gas into it and conducting low-temperature tests;

[0016] Connect the circulation tank with the storage tank. A top liquid inlet pipeline and a bottom liquid inlet pipeline are connected between the circulation tank and the storage tank;

[0017] Set up an evaporation gas recovery pipeline at the top of the circulation tank, and the other end of the evaporation gas recovery pipeline is connected to the storage tank;

[0018] Set up a venting system, which is connected to the top of the circulation tank, and a vent discharge pipeline is arranged between the venting system and the circulation tank;

[0019] When the circulation tank is a hot tank, the storage tank injects liquid into the circulation tank through the bottom liquid inlet pipeline. The vaporized liquid gas returns to the storage tank through the evaporated gas recovery pipeline or enters the venting system through the vent discharge pipeline;

[0020] When the circulation tank is a cold tank, the storage tank injects liquid into the circulation tank through the top liquid inlet pipeline. The vaporized liquid gas returns to the storage tank through the evaporated gas recovery pipeline or enters the venting system through the vent discharge pipeline.

[0021] Advantages of the implementation of the present invention: By setting an evaporated gas recovery pipeline at the top of the circulation tank and connecting it to the storage tank to recover the generated liquefied gas, and by connecting the vent discharge pipeline to the venting system of the circulation tank to vent the flash gas, it is possible to perform low-temperature pump performance tests with different low-temperature media. Different liquid inlet methods are adopted at different temperatures of the circulation tank, reducing the consumption of low-temperature media, without discharging dangerous gases to the outside, reducing the waste of low-temperature media, and achieving green, low-carbon, and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a system block diagram of a circulation tank system and method for testing the performance of a cryogenic pump according to the present invention.

[0024] Reference Numerals:

[0025] 1. Storage tank; 2. Bottom liquid inlet pipeline; 3. Top liquid inlet pipeline; 4. Circulation tank; 5. Circulation tank booster skid; 6. Test pump pool; 7. Evaporated gas recovery pipeline; 8. Vent discharge pipeline; 9. Venting system; 10. Test medium outlet pipeline; 11. Test medium return pipeline; 12. Control valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] Embodiment 1:

[0028] As Figure 1As shown, a circulation tank system for low-temperature pump performance testing includes a circulation tank 4. The circulation tank system for low-temperature pump performance testing is connected to a storage tank 1 and a test pump pool 6. The storage tank 1 is connected to the upper end of the circulation tank 4 through a top liquid inlet pipeline 3 and to the lower end of the circulation tank 4 through a bottom liquid inlet pipeline 2. The circulation tank 4 is connected to the test pump pool 6 through a test medium outlet pipeline 10. The test pump pool 6 is connected to the circulation tank 4 through a test medium return pipeline 11 to realize the circulation and storage of the test medium during the low-temperature pump testing process. An evaporation gas recovery pipeline 7 is provided at the top of the circulation tank 4 and is connected to the storage tank 1. The evaporation recovery pipeline 7 is used to recover the BOG evaporation gas generated during the low-temperature medium test, and a regulating valve 12 is provided on the evaporation gas recovery pipeline 7. The circulation tank system for low-temperature pump performance testing further includes a blow-off system 9 connected to the circulation tank 4 through a blow-off discharge pipeline 8 for discharging the generated liquefied gas. The blow-off system 9 is a flash gas blow-off tower. When the medium in the circulation tank 4 is liquid nitrogen, the generated liquid nitrogen flash gas is introduced into the flash gas blow-off tower through the blow-off discharge pipeline 8 for discharge, so as to keep the pressure inside the circulation tank 4 stable. A regulating valve 12 is provided on the blow-off discharge pipeline 8 for automatically controlling the connection and closing of the flash gas blow-off tower.

[0029] A circulation tank booster skid 5 is connected between the circulation tank 4 and the bottom liquid inlet pipeline 2. The circulation tank booster skid 5 is used to increase and stabilize the pressure of the circulation tank 4 so that the test medium can smoothly enter the test pump pool 6 from the circulation tank 4. A regulating valve 12 is provided on the circulation tank booster skid 5 for controlling the connection and closing of the circulation tank booster skid 5. Reinforcing rings are segmentally installed on the outer wall of the circulation tank 4, and the number of the reinforcing rings is at least five to improve the strength of the circulation tank 4. The type of the circulation tank 4 is vertical, and the designed volume is 100m 3 , the designed temperature of the circulation tank 4 is -196°C, which can meet the testing of low-temperature media such as LNG, LN2, and LPG, meet the testing requirements of various low-temperature pumps, and at the same time meet the requirements of long-term endurance operation assessment of low-temperature pumps. A pressure transmitter and a level transmitter are provided on the side of the circulation tank 4 for measuring and monitoring the pressure and liquid level inside the circulation tank 4. When the circulation tank 4 is a hot tank, the storage tank 1 uses the bottom liquid inlet pipeline 2 to inject liquid into the circulation tank 4. During the injection process, the circulation tank 4 is gradually cooled, and the generated BOG vapor gas is recovered by the top evaporation gas recovery pipeline 7; when the circulation tank 4 is a cold tank, the storage tank 1 uses the top liquid inlet pipeline 3 to inject liquid into the circulation tank 4, which can accelerate the injection speed and save time cost.

[0030] Advantages of the implementation of the present invention: By providing a vapor recovery pipeline 7 at the top of the circulation tank 4 and connecting it to the storage tank 1 to recover the generated liquefied gas, and by connecting the vent discharge pipeline 8 to the venting system 9 of the circulation tank 4 to discharge the flash gas, the performance test of the cryogenic pump can be carried out with different cryogenic media, reducing the consumption of cryogenic media, discharging no dangerous gases to the outside, reducing the waste of cryogenic media, and achieving green, low-carbon and environmental protection.

[0031] Embodiment 2:

[0032] As Figure 1 shown, a circulation tank system for cryogenic pump performance testing includes a circulation tank 4. The circulation tank system for cryogenic pump performance testing is connected to a storage tank 1 and a test pump pool 6. The storage tank 1 is connected to the upper end of the circulation tank 4 through a top liquid inlet pipeline 3 and to the lower end of the circulation tank 4 through a bottom liquid inlet pipeline 2. The circulation tank 4 is connected to the test pump pool 6 through a test medium outlet pipeline 10, and the test pump pool 6 is connected to the circulation tank 4 through a test medium return pipeline 11 to realize the circulation and storage of the test medium during the cryogenic pump test. An evaporation gas recovery pipeline 7 is provided at the top of the circulation tank 4 and connected to the storage tank 1. The evaporation recovery pipeline 7 is used to recover the BOG evaporation gas generated during the cryogenic medium test. A regulating valve 12 is provided on the evaporation gas recovery pipeline 7.

[0033] A circulation tank booster skid 5 is connected between the circulation tank 4 and the bottom liquid inlet pipeline 2. The circulation tank booster skid 5 is used to increase and stabilize the pressure of the circulation tank 4 so that the test medium can smoothly enter the test pump pool 6 from the circulation tank 4. A regulating valve 12 is provided on the circulation tank booster skid 5 to control the connection and closing of the circulation tank booster skid 5. Reinforcing rings are segmentally added to the outer wall of the circulation tank 4, and the number of the reinforcing rings is at least five to improve the strength of the circulation tank 4. The type of the circulation tank 4 is vertical, and the designed volume is 100m 3 , the designed temperature of the circulation tank 4 is -196°C, which meets the testing requirements of cryogenic media such as LNG, LN2, LPG, etc., meets the testing needs of various cryogenic pumps, and at the same time meets the requirements of long-term durability operation assessment of cryogenic pumps. Pressure transmitters and level transmitters are provided on the side of the circulation tank 4 to measure and monitor the pressure and liquid level inside the circulation tank 4. When the circulation tank 4 is a cold tank, the storage tank 1 uses the top liquid inlet pipeline 3 to inject liquid into the circulation tank 4, which can accelerate the liquid injection speed and save time cost.

[0034] In this embodiment, the test medium is LNG (liquefied natural gas), and the circulation tank 4 is set as a cold tank. The LNG gas enters the circulation tank 4 from the top through the top liquid inlet pipeline 3 to accelerate the liquid injection speed. A small amount of vaporized LNG gas generated during the liquid injection process is recovered through the vapor recovery pipeline 7 at the top of the circulation tank 4 to the LNG storage tank 1 within the liquefaction plant area, realizing the cyclic recovery of LNG, thereby avoiding the waste of LNG. The LNG medium enters the test pump pool 6 through the test medium liquid outlet pipeline 10 at the bottom of the circulation tank 4, and then enters the circulation tank 4 from the test pump pool 6 through the test medium return pipeline 11, realizing the circulation and storage of the test medium during the low-temperature pump test process.

[0035] Advantages of the implementation of the present invention: By providing a vapor recovery pipeline 7 at the top of the circulation tank 4 and connecting it to the storage tank 1 to recover the generated liquefied gas, the performance test of the low-temperature pump is carried out with different low-temperature media, reducing the consumption of low-temperature media, without discharging dangerous gases to the outside, reducing the waste of low-temperature media, and realizing green, low-carbon, and environmental protection.

[0036] Embodiment Three:

[0037] As Figure 1 shown, a circulation tank system for low-temperature pump performance testing includes a circulation tank 4. The circulation tank system for low-temperature pump performance testing is connected to the storage tank 1 and the test pump pool 6. The storage tank 1 is communicated with the upper end of the circulation tank 4 through the top liquid inlet pipeline 3 and is communicated with the lower end of the circulation tank 4 through the bottom liquid inlet pipeline 2. The circulation tank 4 is communicated with the test pump pool 6 through the test medium liquid outlet pipeline 10. The test pump pool 6 is communicated with the circulation tank 4 through the test medium return pipeline 11, realizing the circulation and storage of the test medium during the low-temperature pump test process. An evaporation gas recovery pipeline 7 is provided at the top of the circulation tank 4 and is connected to the storage tank 1. The evaporation recovery pipeline 7 is used to recover the BOG evaporation gas generated during the low-temperature medium test. A regulating valve 12 is provided on the evaporation gas recovery pipeline 7.

[0038] A circulation tank booster skid 5 is connected between the circulation tank 4 and the bottom liquid inlet pipeline 2. The circulation tank booster skid 5 is used to increase and stabilize the pressure of the circulation tank 4, so that the test medium can smoothly enter the test pump pool 6 from the circulation tank 4. A regulating valve 12 is provided on the circulation tank booster skid 5 to control the connection and closing of the circulation tank booster skid 5. Reinforcing rings are segmentally added to the outer wall of the circulation tank 4, and the number of the reinforcing rings is at least five to improve the strength of the circulation tank 4. The type of the circulation tank 4 is vertical, and the designed volume is 100m 3, the design temperature of the circulation tank 4 is -196°C, which meets the requirements for testing low-temperature media such as LNG, LN2, and LPG, satisfies the testing needs of various low-temperature pumps, and also meets the requirements for long-term endurance operation assessment of low-temperature pumps. A pressure transmitter and a level transmitter are provided on the side of the circulation tank 4 to measure and monitor the pressure and liquid level inside the circulation tank 4. When the circulation tank 4 is a hot tank, the storage tank 1 uses the bottom liquid injection pipeline 2 to inject liquid into the circulation tank 4. During the liquid injection process, the circulation tank 4 is gradually cooled, and the vaporized gas generated is recovered by the top vapor recovery pipeline 7. At the same time, filling and cooling are carried out, which is conducive to the BOG vapor being discharged from the top flash vapor recovery pipeline 7.

[0039] In this embodiment, the test medium is LNG liquefied natural gas, and the circulation tank 4 is set as a hot tank. The LNG gas enters the circulation tank 4 through the bottom liquid injection pipeline 2. During the liquid injection process, the circulation tank 4 is gradually cooled. At this time, a small amount of LNG vaporized gas generated is recovered to the LNG storage tank 1 in the liquefaction plant area through the vapor recovery pipeline 7 at the top of the circulation tank 4, realizing the cyclic recovery of LNG, thereby avoiding the waste of LNG. The LNG medium enters the test pump pool 6 through the test medium liquid outlet pipeline 10 at the bottom of the circulation tank 4, and then enters the circulation tank 4 from the test pump pool 6 through the test medium return pipeline 11, realizing the circulation and storage of the test medium during the low-temperature pump test.

[0040] Advantages of the implementation of the present invention: By setting a vapor recovery pipeline 7 at the top of the circulation tank 4 and connecting it to the storage tank 1 to recover the generated liquefied gas, the circulation tank system is reasonably designed, enabling the performance test of low-temperature pumps with different low-temperature media, reducing the consumption of low-temperature media, discharging no dangerous gases to the outside, reducing the waste of low-temperature media, and achieving green, low-carbon, and environmental protection.

[0041] Embodiment 4:

[0042] As Figure 1As shown in the figure, a circulation tank system for low-temperature pump performance testing includes a circulation tank 4. The circulation tank system for low-temperature pump performance testing is connected to a storage tank 1 and a test pump pool 6. The storage tank 1 is connected to the upper end of the circulation tank 4 through a top liquid inlet pipeline 3 and to the lower end of the circulation tank 4 through a bottom liquid inlet pipeline 2. The circulation tank 4 is connected to the test pump pool 6 through a test medium outlet pipeline 10. The test pump pool 6 is connected to the circulation tank 4 through a test medium return pipeline 11 to realize the circulation and storage of the test medium during the low-temperature pump testing process. The circulation tank system for low-temperature pump performance testing further includes a relief system 9 connected to the circulation tank 4 through a vent discharge pipeline 8 for discharging the generated liquefied gas. The relief system 9 is a flash gas relief tower. When the medium in the circulation tank 4 is liquid nitrogen, the generated liquid nitrogen flash gas is introduced into the flash gas relief tower through the vent discharge pipeline 8 for discharge, so as to keep the pressure inside the circulation tank 4 stable. A regulating valve 12 is provided on the vent discharge pipeline 8 for automatically controlling the connection and closing of the flash gas relief tower.

[0043] A circulation tank booster skid 5 is connected between the circulation tank 4 and the bottom liquid inlet pipeline 2. The circulation tank booster skid 5 is used to increase and stabilize the pressure of the circulation tank 4 so that the test medium can smoothly enter the test pump pool 6 from the circulation tank 4. A regulating valve 12 is provided on the circulation tank booster skid 5 for controlling the connection and closing of the circulation tank booster skid 5. Reinforcing rings are segmentally added to the outer wall of the circulation tank 4, and the number of the reinforcing rings is at least five to improve the strength of the circulation tank 4. The type of the circulation tank 4 is vertical, and the designed volume is 100m 3 , the designed temperature of the circulation tank 4 is -196 °C, which can meet the testing of low-temperature media such as LNG, LN2, and LPG, meet the testing requirements of various low-temperature pumps, and at the same time meet the requirements of long-term durability operation assessment of low-temperature pumps. A pressure transmitter and a level transmitter are provided on the side of the circulation tank 4 for measuring and monitoring the pressure and liquid level inside the circulation tank 4. When the circulation tank 4 is a hot tank, the storage tank 1 uses the bottom liquid inlet pipeline 2 to inject liquid into the circulation tank 4. During the injection process, the circulation tank 4 is gradually cooled, and the generated vaporized gas is recovered by the top vapor recovery pipeline 7. At the same time, filling and cooling are carried out, which is beneficial to the discharge of BOG vapor from the top.

[0044] In this embodiment, the test medium is LN2 liquid nitrogen, and the circulation tank 4 is set as a hot tank. The LN2 liquid enters the circulation tank 4 through the bottom liquid inlet pipeline 2. During the liquid injection process, the circulation tank 4 is gradually cooled. At this time, a small amount of vaporized LN2 gas generated enters the flash gas release tower through the vent discharge pipeline 8 for nitrogen discharge, thereby ensuring the stable pressure in the circulation tank 4, facilitating the stability of the entire test system, and improving the accuracy of the LN2 cryogenic pump test system. The LN2 medium enters the test pump pool 6 through the test medium liquid outlet pipeline 10 at the bottom of the circulation tank 4, and then enters the circulation tank 4 from the test pump pool 6 through the test medium return pipeline 11, realizing the circulation and storage of the test medium during the cryogenic pump test process.

[0045] Advantages of the implementation of the present invention: The flash gas is discharged through the vent discharge pipeline 8 connected to the release system 9 of the circulation tank 4, enabling the performance test of the cryogenic pump with different cryogenic media, reducing the consumption of cryogenic media, without discharging dangerous gases to the outside, reducing the waste of cryogenic media, and achieving green, low-carbon, and environmental protection.

[0046] Embodiment Five:

[0047] As Figure 1 shown, a circulation tank system for cryogenic pump performance testing includes a circulation tank 4. The circulation tank system for cryogenic pump performance testing is connected to a storage tank 1 and a test pump pool 6. The storage tank 1 is connected to the upper end of the circulation tank 4 through a top liquid inlet pipeline 3 and to the lower end of the circulation tank 4 through a bottom liquid inlet pipeline 2. The circulation tank 4 is connected to the test pump pool 6 through a test medium liquid outlet pipeline 10, and the test pump pool 6 is connected to the circulation tank 4 through a test medium return pipeline 11, realizing the circulation and storage of the test medium during the cryogenic pump test process. The circulation tank system for cryogenic pump performance testing further includes a release system 9 connected to the circulation tank 4 through a vent discharge pipeline 8 for discharging the generated liquefied gas. The release system 9 is a flash gas release tower. When the medium in the circulation tank 4 is liquid nitrogen, the generated liquid nitrogen flash gas is introduced into the flash gas release tower through the vent discharge pipeline 8 for discharge, so that the pressure inside the circulation tank 4 remains stable. A regulating valve 12 is provided on the vent discharge pipeline 8 for automatically controlling the connection and closing of the flash gas release tower.

[0048] A circulation tank booster skid 5 is connected between the circulation tank 4 and the bottom liquid inlet pipeline 2. The circulation tank booster skid 5 is used to increase and stabilize the pressure of the circulation tank 4, enabling the test medium to smoothly enter the test pump pool 6 from the circulation tank 4. A regulating valve 12 is provided on the circulation tank booster skid 5 for controlling the connection and closing of the circulation tank booster skid 5. Reinforcing rings are segmented and equipped on the outer wall of the circulation tank 4, and the number of the reinforcing rings is at least five to improve the strength of the circulation tank 4. The type of the circulation tank 4 is vertical, and the designed volume is 100m 3, the design temperature of the circulation tank 4 is -196°C, which can meet the testing requirements of low-temperature media such as LNG, LN2, and LPG, and can meet the testing needs of various low-temperature pumps. At the same time, it can meet the requirements of long-term endurance operation assessment of low-temperature pumps. A pressure transmitter and a liquid level transmitter are arranged on the side of the circulation tank 4 to measure and monitor the pressure and liquid level height inside the circulation tank 4. When the circulation tank 4 is a cold tank, the storage tank 1 uses the top liquid inlet pipeline 3 to inject liquid into the circulation tank 4, which can accelerate the liquid injection speed and save time costs.

[0049] In this embodiment, the test medium is LN2 liquid nitrogen, and the circulation tank 4 is set as a cold tank. The LN2 liquid enters the circulation tank 4 from the top through the top liquid inlet pipeline 3, which can accelerate the liquid injection speed and save time costs. A small amount of vaporized LN2 gas generated during the liquid injection process enters the flash gas discharge tower through the vent discharge pipeline 8 for nitrogen discharge, thereby ensuring the pressure stability inside the circulation tank 4, being beneficial to the stability of the entire test system, and improving the accuracy of the LN2 low-temperature pump test system. The LN2 medium enters the test pump pool 6 through the test medium outlet pipeline 10 at the bottom of the circulation tank 4, and then enters the circulation tank 4 from the test pump pool 6 through the test medium return pipeline 11 to realize the circulation and storage of the test medium during the low-temperature pump test.

[0050] The advantages of the implementation of the present invention: The flash gas is emptied through the vent discharge system 9 connected to the circulation tank 4 through the vent discharge pipeline 8, realizing the performance test of low-temperature pumps with different low-temperature media, reducing the consumption of low-temperature media, without discharging dangerous gases to the outside, reducing the waste of low-temperature media, and achieving green, low-carbon, and environmental protection.

[0051] Embodiment Six:

[0052] A test method for a circulation tank for low-temperature pump performance testing is realized based on a circulation tank system for low-temperature pump performance testing as shown in Embodiment One, and includes the following steps:

[0053] S1: Set up the circulation tank 4 to add liquid gas into it and conduct low-temperature tests.

[0054] S2: Connect the circulation tank 4 with the storage tank 1, and a top liquid inlet pipeline 3 and a bottom liquid inlet pipeline 2 are connected between the circulation tank 4 and the storage tank 1.

[0055] The circulation tank system for low-temperature pump performance testing is connected to the storage tank 1 and the test pump pool 6. The storage tank 1 is connected to the upper end of the circulation tank 4 through the top liquid inlet pipeline 3 and is connected to the lower end of the circulation tank 4 through the bottom liquid inlet pipeline 2. The circulation tank 4 is connected to the test pump pool 6 through the test medium outlet pipeline 10, and the test pump pool 6 is connected to the circulation tank 4 through the test medium return pipeline 11 to realize the circulation and storage of the test medium during the low-temperature pump test.

[0056] S3: An evaporation gas recovery pipeline 7 is provided at the top of the circulation tank 4, and the other end of the evaporation gas recovery pipeline 7 is connected to the storage tank 1.

[0057] An evaporation gas recovery pipeline 7 is provided at the top of the circulation tank 4 and is connected to the storage tank 1. The evaporation recovery pipeline 7 is used to recover the BOG evaporation gas generated during the low-temperature medium test. A regulating valve 12 is provided on the evaporation gas recovery pipeline 7.

[0058] S4: A venting system 9 is provided and connected to the top of the circulation tank 4. A venting and discharging pipeline 8 is provided between the venting system 9 and the circulation tank 4.

[0059] The circulation tank system for low-temperature pump performance testing further includes a venting system 9 connected to the circulation tank 4 through a venting and discharging pipeline 8, which is used to discharge the generated liquefied gas. The venting system 9 is a flash gas venting tower. When the medium in the circulation tank 4 is liquid nitrogen, the generated liquid nitrogen flash gas is introduced into the flash gas venting tower through the venting and discharging pipeline 8 for discharge, so that the pressure inside the circulation tank 4 remains stable. A regulating valve 12 is provided on the venting and discharging pipeline 8, which is used to automatically control the connection and closing of the flash gas venting tower.

[0060] A circulation tank booster skid 5 is connected between the circulation tank 4 and the bottom liquid inlet pipeline 2. The circulation tank booster skid 5 is used to increase and stabilize the pressure of the circulation tank 4, so that the test medium can smoothly enter the test pump sump 6 from the circulation tank 4. A regulating valve 12 is provided on the circulation tank booster skid 5, which is used to control the connection and closing of the circulation tank booster skid 5. Reinforcing rings are segmentally equipped on the outer wall of the circulation tank 4, and the number of the reinforcing rings is at least five to improve the strength of the circulation tank 4. The type of the circulation tank 4 is vertical, and the designed volume is 100m 3 , the designed temperature of the circulation tank 4 is -196°C, which can meet the testing of low-temperature media such as LNG, LN2, and LPG, meet the testing requirements of various low-temperature pumps, and at the same time meet the requirements of long-term endurance operation assessment of low-temperature pumps. A pressure transmitter and a liquid level transmitter are provided on the side of the circulation tank 4, which are used to measure and monitor the pressure and liquid level height inside the circulation tank 4.

[0061] The order of steps S2, S3, and S4 can be interchanged.

[0062] S5: When the circulation tank 4 is a hot tank, the storage tank 1 injects liquid into the circulation tank 4 through the bottom liquid inlet pipeline 2, and the vaporized liquid gas returns to the storage tank 1 through the evaporation gas recovery pipeline 7, or enters the venting system 9 through the venting and discharging pipeline 8.

[0063] S6: When the circulation tank 4 is a cold tank, the storage tank 1 injects liquid into the circulation tank 4 through the top liquid inlet pipeline 3, and the vaporized liquid gas returns to the storage tank 1 through the evaporation gas recovery pipeline 7, or enters the venting system through the venting and discharging pipeline 8.

[0064] The order of steps S5 and S6 can be interchanged.

[0065] Advantages of the implementation of the present invention: By providing a vapor recovery pipeline 7 at the top of the circulation tank 4 and connecting it to the storage tank 1 to recover the generated liquefied gas, and by connecting the vent discharge pipeline 8 to the venting system 9 of the circulation tank 4 to vent the flash gas, the performance test of the cryogenic pump is realized using different cryogenic media. Different liquid inlet methods are adopted at different temperatures of the circulation tank 4, reducing the consumption of cryogenic media, discharging no dangerous gases to the outside, reducing the waste of cryogenic media, and achieving green, low-carbon, and environmental protection.

[0066] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A circulating tank system for testing the performance of a cryogenic pump, comprising a circulating tank (4), wherein the circulating tank system for testing the performance of a cryogenic pump is connected to a storage tank (1) and a test pump pool (6), wherein the storage tank (1) is connected to the upper end of the circulating tank (4) via a top liquid inlet pipeline (3), and is connected to the lower end of the circulating tank (4) via a bottom liquid inlet pipeline (2), wherein the circulating tank (4) is connected to the test pump pool (6) via a test medium liquid outlet pipeline (10), and wherein the test pump pool (6) is connected to the circulating tank (4) via a test medium return pipeline (11), thereby realizing the circulation and storage of the test medium during the cryogenic pump test, characterized in that: The top of the circulation tank (4) is provided with an evaporation gas recovery pipeline (7) and is connected to the storage tank (1). The circulation tank system for testing the performance of the cryogenic pump also includes a venting system (9) connected to the circulation tank (4) via a venting and exhausting pipeline (8). The evaporation gas recovery pipeline (7) and the exhausting system (9) are used to recover or exhaust different liquefied gases generated. When the circulation tank (4) is a hot tank, the storage tank (1) uses a bottom liquid inlet pipeline (2) to inject liquid into the circulation tank (4); when the circulation tank (4) is a cold tank, the storage tank (1) uses a top liquid inlet pipeline (3) to inject liquid into the circulation tank (4).

2. A circulating tank system for testing the performance of a cryogenic pump according to claim 1, characterized in that: The release system (9) is a flash gas release tower. When the medium in the circulation tank (4) is liquid nitrogen, the generated liquid nitrogen flash gas is introduced into the flash gas release tower through a venting discharge pipeline (8) for discharge, so that the pressure inside the circulation tank (4) remains stable.

3. A circulating tank system for testing the performance of a cryogenic pump according to claim 2, characterized in that: The venting discharge pipeline (8) is provided with a regulating valve (12), and the regulating valve (12) is used to automatically control the connection and closing of the flash gas venting tower.

4. A circulating tank system for testing the performance of a cryogenic pump according to claim 1, characterized in that: A circulation tank pressure boosting skid (5) is connected between the circulation tank (4) and the bottom liquid inlet pipeline (2), and the circulation tank pressure boosting skid (5) is used to increase and stabilize the pressure of the circulation tank (4) so ​​that the test medium can smoothly enter the test pump pool (6) from the circulation tank (4).

5. A circulation tank system for testing the performance of a cryogenic pump according to claim 4, characterized in that: The circulation tank boosting skid (5) is provided with a regulating valve (12), and the regulating valve (12) is used to control the connection and closing of the circulation tank boosting skid (5).

6. A circulating tank system for testing the performance of a cryogenic pump according to claim 1, characterized in that: The outer wall of the circulation tank (4) is provided with reinforcement rings in sections, and the number of the reinforcement rings is at least five.

7. A circulating tank system for testing the performance of a cryogenic pump according to claim 1, characterized in that: The circulation tank (4) is vertical in type and has a designed volume of 100m 3 The design temperature of the circulation tank (4) is -196°C.

8. A circulating tank system for testing the performance of a cryogenic pump according to claim 1, characterized in that: The side of the circulation tank (4) is provided with a pressure transmitter and a liquid level transmitter, which are used to measure and monitor the pressure and liquid level inside the circulation tank (4).

9. A circulation tank system for testing the performance of a cryogenic pump according to any one of claims 1 to 8, characterized in that: When the test medium is liquefied natural gas, boil-off gas is generated during testing in the circulation tank (4), and the boil-off gas is recovered back to the storage tank (1) through a boil-off gas recovery pipeline (7) at the top of the circulation tank (4).

10. A method for testing a circulating tank for testing the performance of a cryogenic pump, characterized in that: The following steps are involved: A circulation tank (4) is provided for adding liquid gas therein and performing low temperature testing; The circulation tank (4) is connected to the storage tank (1), and a top liquid inlet pipeline (3) and a bottom liquid inlet pipeline (2) are connected between the circulation tank (4) and the storage tank (1); A vapor recovery pipeline (7) is arranged on the top of the circulation tank (4), and the other end of the vapor recovery pipeline (7) is connected to the storage tank (1); A venting system (9) is provided, connected to the top of the circulation tank (4), and a venting discharge pipeline (8) is provided between the venting system (9) and the circulation tank (4); When the circulation tank (4) is a hot tank, the storage tank (1) uses the bottom liquid inlet pipeline (2) to inject liquid into the circulation tank (4), and the vaporized liquid gas returns to the storage tank (1) through the evaporation gas recovery pipeline (7), or enters the release system (9) through the venting and discharge pipeline (8); When the circulation tank (4) is a cold tank, the storage tank (1) uses the top liquid inlet pipeline (3) to inject liquid into the circulation tank (4), and the vaporized liquid gas returns to the storage tank (1) through the evaporation gas recovery pipeline (7), or enters the release system (9) through the venting and discharge pipeline (8).

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