System and method for testing evaporation rate of low-temperature storage tank

Abstract

The invention provides a low-temperature storage tank evaporation rate testing system and a testing method thereof. The low-temperature storage tank evaporation rate testing system comprises a liquid outlet pipeline, a temperature returning device, an exhaust pipeline, a testing pipeline, a first valve, an emptying pipeline and a testing assembly. One end of the liquid outlet pipeline is communicated with the low-temperature storage tank; the temperature returner is communicated with the other end of the liquid outlet pipeline; one end of the exhaust pipeline is communicated with the temperature returning device; one end of the test pipeline is communicated with the temperature return device, and the test pipeline and the exhaust pipeline are arranged in parallel; the first valve is communicated with the test pipeline; one end of the emptying pipeline is communicated with one end of the test pipeline and the exhaust pipeline far away from the temperature recuperator, and the other end is provided with an emptying port; the test assembly is used for detecting the state information of the gaseous medium in the test pipeline. According to the low-temperature storage tank evaporation rate testing system, the exhaust pipeline connected with the testing pipeline in parallel is arranged, so that air flow sequentially passes through the testing pipeline and the emptying pipeline instead of the testing pipeline when the low-temperature storage tank is emptied, and the phenomenon that the precision is reduced and even the low-temperature storage tank is damaged due to over-travel operation of a measuring instrument communicated with the testing pipeline is avoided.

Description

Technical Field

[0001] This invention relates to the field of performance testing of cryogenic storage tank equipment, and in particular to a system and method for testing the evaporation rate of cryogenic storage tanks. Background Technology

[0002] In recent years, high-vacuum equipment has been used more and more, especially in cryogenic equipment containing liquefied gases. Static evaporation rate is a very important performance indicator for cryogenic storage tanks. When testing the evaporation rate of a cryogenic storage tank, the liquid inside the tank must be vented until the tank reaches zero gauge pressure before the state information of the gaseous medium in the pipeline can be tested. Because cryogenic storage tanks are high-pressure vessels, when testing the evaporation rate of some cryogenic storage tanks with high internal pressure (such as liquid hydrogen tanks), excessive flow in the venting pipeline during the venting process may cause the measuring instrument to overtravel, resulting in decreased accuracy or even damage. Summary of the Invention

[0003] One objective of this invention is to address the shortcomings of the prior art by providing a cryogenic storage tank evaporation rate testing system that can effectively prevent damage to measuring instruments when venting a cryogenic storage tank.

[0004] To solve the above-mentioned technical problems, this application adopts the following technical solution: a cryogenic storage tank evaporation rate testing system, installed on the cryogenic storage tank, comprising: A liquid outlet pipeline, one end of which is connected to the cryogenic storage tank, is used to guide out the liquid medium inside the cryogenic storage tank; A reheater, which is connected to the other end of the liquid outlet pipe, heats and vaporizes the liquid medium flowing out of the liquid outlet pipe to form a gaseous medium; An exhaust pipe, one end of which is connected to the reheater; A test pipeline, one end of which is connected to the regenerator, and the test pipeline and the exhaust pipeline are connected in parallel; A first valve, which is connected to the test pipeline, is used to control the on / off state of the test pipeline; The venting pipeline has one end connected to the end of the test pipeline away from the regenerator and the end of the exhaust pipeline away from the regenerator, and the other end is provided with a venting port. The testing component is used to detect the state information of the gaseous medium inside the testing pipeline.

[0005] In one embodiment, the cryogenic storage tank is used to load liquid hydrogen, and the testing component is used to detect the state information of hydrogen in the testing pipeline.

[0006] In one embodiment, a recorder is also included, which is communicatively connected to the test component.

[0007] In one embodiment, the recorder includes a communication module for communicating with an external network device to upload the data recorded by the recorder to the external network device.

[0008] In one embodiment, an explosion-proof control box is also included, and the recorder is disposed inside the explosion-proof control box.

[0009] In one embodiment, the test assembly includes a flow meter, a pressure sensor, a temperature sensor, an ambient temperature sensor, and an atmospheric pressure sensor; the flow meter, pressure sensor, and temperature sensor are all connected to the test pipeline, and are all located downstream of the first valve; the flow meter, pressure sensor, and temperature sensor are used to detect the flow rate, pressure, and temperature in the test pipeline, respectively; the ambient temperature sensor and atmospheric pressure sensor are used to detect the ambient temperature and atmospheric pressure, respectively.

[0010] In one embodiment, a second valve is also included, which is connected to the exhaust pipe and is used to control the opening and closing of the exhaust pipe.

[0011] In one embodiment, the system further includes a purge line and a third valve; one end of the purge line is connected to the liquid outlet line, and the other end is provided with a purge port; the third valve is connected to the purge line and is used to control the on / off state of the purge line.

[0012] In one embodiment, the liquid outlet pipeline includes a connecting portion and a flexible pipeline, with the connecting portion provided at both ends of the flexible pipeline, and the two ends of the liquid outlet pipeline respectively connected to the cryogenic storage tank and the reheater through the connecting portion.

[0013] In one embodiment, the system further includes a sampling pipeline and a fourth valve; one end of the sampling pipeline is connected to the venting pipeline, and the other end is provided with a sampling port; the fourth valve is connected to the sampling pipeline and is used to control the on / off state of the sampling pipeline.

[0014] In one embodiment, a grounding terminal is also included, which is electrically connected to the exhaust pipe or vent pipe.

[0015] This application also employs a method for testing the evaporation rate of cryogenic storage tanks, applicable to the aforementioned cryogenic storage tank evaporation rate testing system, comprising the following steps: The first valve is closed, and the liquid outlet pipeline and the vent pipeline are connected through the exhaust pipeline; The liquid outlet pipeline is connected to the cryogenic storage tank, and the liquid medium flowing out of the liquid outlet pipeline is vaporized into a gaseous medium through the reheater; The gaseous medium is released through the exhaust pipe and the vent pipe until the gauge pressure of the cryogenic storage tank returns to zero; Open the first valve to connect the liquid outlet line and the vent line through the test line; The state information of the gaseous medium in the test pipeline is detected using the test component. The evaporation rate is calculated based on the detected state information of the gaseous medium.

[0016] As can be seen from the above technical solution, this application has at least the following advantages and positive effects: The cryogenic storage tank evaporation rate testing system disclosed in this application sets up an exhaust pipe connected in parallel with the test pipe. The exhaust pipe is used to vent the cryogenic storage tank. During the venting process of the cryogenic storage tank, the large flow of air is discharged through the test pipe and the venting pipe in sequence without passing through the test pipe. This avoids the phenomenon of overtravel of the measuring instruments connected to the test pipe, which may lead to decreased accuracy or even damage.

[0017] The evaporation rate test method for cryogenic storage tanks disclosed in this application blocks the test pipeline when the storage tank is vented, allowing the venting airflow from the cryogenic storage tank to flow through the exhaust pipeline and the venting pipeline. After the cryogenic storage tank is vented, the first valve is opened to connect the rewarmer and the test pipeline, allowing the naturally evaporated gas in the cryogenic storage tank to enter the test pipeline for testing. This method can effectively avoid the phenomenon that the large flow of air during the venting process of the cryogenic storage tank causes the measuring instrument to overtravel, resulting in decreased accuracy or even damage. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a cryogenic storage tank evaporation rate testing system according to an embodiment of this application; Figure 2 This is a flowchart of a method for testing the evaporation rate of a cryogenic storage tank according to an embodiment of this application.

[0019] The annotations in the attached figures are explained as follows: 1. Liquid outlet pipeline; 11. Connection part; 12. Flexible pipeline; 2. Warm-up device; 3. Exhaust pipe; 31. Second valve; 4. Test pipeline; 41. First valve; 5. Vent line; 51. Vent port; 52. Sampling line; 53. Fourth valve; 54. Sampling port; 61. Flow meter; 62. Pressure sensor; 63. Temperature sensor; 64. Ambient temperature sensor; 65. Atmospheric pressure sensor; 7. Recorder; 71. Explosion-proof control box; 8. Purge pipeline; 81. Third valve; 82. Purge port; 9. Grounding terminal. Detailed Implementation

[0020] Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0021] In the description of this application, it should be understood that, in the embodiments shown in the accompanying drawings, the indications of direction or positional relationships (such as up, down, left, right, front, and back, etc.) are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. These descriptions are appropriate when these elements are in the positions shown in the accompanying drawings. If the description of the positions of these elements changes, these directional indications also change accordingly.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] In recent years, high-vacuum equipment has been used more and more, especially in cryogenic equipment for storing liquefied gases. Static evaporation rate is a very important performance indicator for cryogenic storage tanks. When testing the evaporation rate of a cryogenic storage tank, the liquid inside must first be vented until the tank reaches zero gauge pressure before the state of the gaseous medium in the pipeline can be tested. Because cryogenic storage tanks are high-pressure vessels, the gas flow rate in the venting pipeline is relatively large during the venting process. This phenomenon is more pronounced in some cryogenic tanks with higher internal pressure and faster evaporation rates of the internal liquid medium, such as liquid hydrogen tanks. The hydrogen storage pressure in liquid hydrogen tanks is generally below 5 Bar, with a maximum of no more than 8.5 Bar, and the boiling point of liquid hydrogen is as low as -252.87℃, causing it to evaporate rapidly after leaving the cryogenic tank. Compared to liquid nitrogen tanks, liquid hydrogen tanks generate a larger flow rate of gas in the venting pipeline during venting. If the measuring instrument used to test the state information of the gaseous medium in the pipeline is directly connected to the venting pipeline used to vent the liquid hydrogen storage tank, the large flow of gas in the pipeline during the venting process can easily cause the measuring instrument to run beyond its travel range, resulting in a decrease in the accuracy of the measuring instrument or even damage.

[0024] To address the above situation, this application proposes a solution that involves setting up a test pipeline 4 and an exhaust pipeline 3 in parallel. When the cryogenic storage tank is vented, the test pipeline 4 is closed, and the exhaust pipeline 3 and the venting pipeline 5 are used for venting. After venting, the test pipeline 4 is connected to the rewarmer 2, and the test component detects the state information of the gaseous medium in the test pipeline 4 to calculate the evaporation rate. This approach can avoid the phenomenon that the large flow of air during the venting process of the cryogenic storage tank causes the measuring instrument to overtravel, resulting in decreased accuracy or even damage.

[0025] Figure 1 A schematic diagram of the structure of a cryogenic storage tank evaporation rate testing system provided in one embodiment of this application is disclosed.

[0026] See Figure 1 The cryogenic storage tank evaporation rate testing system, installed on the cryogenic storage tank, includes an outlet pipe 1, a reheater 2, an exhaust pipe 3, a test pipe 4, a first valve 41, a vent pipe 5, and test components (not shown in the figure). The cryogenic storage tank is used to hold liquid hydrogen.

[0027] One end of the liquid outlet pipe 1 is connected to the cryogenic storage tank to guide the liquid medium inside the cryogenic storage tank. Specifically, one end of the liquid outlet pipe 1 is connected to the pipeline outlet of the cryogenic storage tank, so that the liquid medium inside the cryogenic storage tank can flow out along the liquid outlet pipe 1.

[0028] At the same time, the reheater 2 is connected to the other end of the liquid outlet pipe 1, so that the liquid medium flowing out of the liquid outlet pipe 1 enters the reheater 2. The reheater 2 can heat the liquid medium flowing out of the liquid outlet pipe 1, so that the liquid medium entering the reheater 2 vaporizes into a gaseous medium and flows out from the other end of the reheater 2.

[0029] One end of the exhaust pipe 3 is connected to the reheater 2. Specifically, one end of the exhaust pipe 3 is connected to the end of the reheater 2 away from the liquid outlet pipe 1, so that the gaseous medium vaporized in the reheater 2 can flow from one end of the exhaust pipe 3 to the other end of the exhaust pipe 3.

[0030] One end of the test line 4 is connected to the end of the reheater 2 that is away from the liquid outlet line 1, and the test line 4 and the exhaust line 3 are connected in parallel.

[0031] The first valve 41 is connected to the test pipeline 4 and is used to control the opening and closing of the test pipeline 4. Specifically, the first valve 41 is a cryogenic shut-off valve. When the first valve 41 is in the open state, the gaseous medium formed by the vaporization of the liquid medium in the cryogenic storage tank can flow into the test pipeline 4 along the liquid outlet pipeline 1 and the return pipeline; when the first valve 41 is in the closed state, the gaseous medium formed by the vaporization of the liquid medium in the storage tank cannot flow into the test pipeline 4 along the liquid outlet pipeline 1 and the return pipeline.

[0032] One end of the vent pipe 5 is connected to the end of the test pipe 4 away from the regenerator 2 and the end of the exhaust pipe 3 away from the regenerator 2, and the other end is provided with a vent port 51. Specifically, the vent port 51 is at a height of not less than 6m above the ground to meet the safety requirements for hydrogen emission.

[0033] The testing component is used to detect the state information of the gaseous medium within the test pipeline 4. Operators can calculate the evaporation rate of the cryogenic storage tank based on the state information of the gaseous medium detected by the testing component. In this embodiment, the gaseous medium is hydrogen.

[0034] In the technical solution provided in this application embodiment, the liquid outlet pipeline 1 includes a connecting part 11 and a flexible pipeline 12. The two ends of the flexible pipeline 12 are respectively provided with connecting parts 11, and the two ends of the liquid outlet pipeline 1 are respectively connected to the cryogenic storage tank and the regenerator 2 through the connecting parts 11. It is easily understood that the flexible pipeline 12 makes the cryogenic storage tank evaporation rate testing system and the cryogenic storage tank a flexible connection, facilitating disassembly and reassembly.

[0035] It should be noted that when selecting the model or size of the regenerator 2, the pressurization rate can be determined based on the limiting evaporation rate of the cryogenic storage tank, and the required heat exchange area of ​​the regenerator 2 can be calculated. This allows for the selection of a regenerator 2 with a length that meets the usage requirements. Increasing the length of the regenerator 2 extends the reaction time for the liquid medium to vaporize into a gaseous medium, ensuring that the liquid medium is fully vaporized and helping to improve the accuracy of the measurement data.

[0036] In one embodiment, a second valve 31 can also be connected to the exhaust pipe 3, which is used to control the opening and closing of the exhaust pipe 3. Specifically, the second valve 31 is a cryogenic shut-off valve. When the second valve 31 is open, the gaseous medium vaporized in the regenerator 2 can flow from one end of the exhaust pipe 3 to the other end and then into the vent pipe 5; when the second valve 31 is closed, the gaseous medium vaporized in the regenerator 2 cannot flow from one end of the exhaust pipe 3 to the other end and then into the vent pipe 5. It is easy to understand that after venting the cryogenic storage tank, opening the first valve 41 and closing the second valve 31 allows the gaseous medium that naturally evaporates in the cryogenic storage tank to flow only into the vent pipe 5 through the test pipe 4, avoiding interference from the exhaust pipe 3, which is beneficial to improving the testing efficiency and accuracy of the test components.

[0037] The test components include a flow meter 61, a pressure sensor 62, a temperature sensor 63, an ambient temperature sensor 64, and an atmospheric pressure sensor 65. The flow meter 61, pressure sensor 62, and temperature sensor 63 are all connected to the test pipeline 4, and are all located downstream of the first valve 41. The flow meter 61, pressure sensor 62, and temperature sensor 63 are used to detect the flow rate, pressure, and temperature within the test pipeline 4, respectively; the ambient temperature sensor 64 and atmospheric pressure sensor 65 are used to detect the ambient temperature and atmospheric pressure, respectively.

[0038] In the technical solution provided in this application embodiment, the flow meter 61 is a gas mass flow meter 61. In other possible embodiments, the flow meter 61 may be a wet gas flow meter 61.

[0039] Specifically, the test interval for the test components is no more than 1 hour, and the data recording time is 24 hours. The flow rate information obtained from the flow meter 61 is used to calculate the test evaporation rate of the low-pressure storage tank. The data obtained from the flow meter 61, pressure sensor 62, temperature sensor 63, ambient temperature sensor 64, and atmospheric pressure sensor 65 are used to calculate the static evaporation rate of the low-pressure storage tank. The static evaporation rate can be used to verify the validity of the recorded data, and thus verify the validity of the calculated test evaporation rate.

[0040] The cryogenic storage tank evaporation rate testing system provided in this application embodiment also includes a recorder 7, which is communicatively connected to the testing component. The recorder 7 is used to receive the state information of the gaseous medium in the test pipeline 4 detected by the testing component. It is easy to understand that some industrial gases are flammable, explosive, or harmful to the human body. If an accidental leak occurs during testing, it may cause a safety accident. Setting up the recorder 7 can automatically collect various data detected by the testing component, allowing for unmanned operation on site and effectively ensuring the personal safety of personnel.

[0041] The recorder 7 is preferably a paperless recorder. The recorder 7 has a built-in communication module for communicating with external network devices to upload the data recorded by the recorder 7. As is easily understood, with the communication module, data collection from the recorder 7 is eliminated during testing, effectively avoiding human error, and allowing real-time monitoring of data changes.

[0042] The cryogenic storage tank evaporation rate testing system provided in this application embodiment also includes an explosion-proof control box 71, and the recorder 7 is housed inside the explosion-proof control box 71. It is easy to understand that some industrial gases are flammable and explosive, and accidental leaks of such gases can easily lead to deflagration. The explosion-proof control box 71 can reduce the risk of damage to the recorder 7 in an accident.

[0043] In the technical solution provided in this application embodiment, the cryogenic storage tank evaporation rate testing system further includes a purge pipeline 8 and a third valve 81; one end of the purge pipeline 8 is connected to the liquid outlet pipeline 1, and the other end is provided with a purge port 82; the third valve 81 is connected to the purge pipeline 8 and is used to control the on / off state of the purge pipeline 8. Specifically, the third valve 81 is a needle valve; the connection between the purge pipeline 8 and the liquid outlet pipeline 1 is located upstream of the flexible pipeline 12. The purge port 82 is mainly used for purging and venting. When performing dew point testing or air pressure and air tightness testing in this cryogenic storage tank evaporation rate testing system, the purge port 82 can also be used as an air inlet.

[0044] It should be noted that a dew point test and a pressure and airtightness test must be performed before using this cryogenic storage tank evaporation rate testing system.

[0045] The specific steps for the dew point test are as follows: Nitrogen gas is passed through purge port 82 to fill the pipeline of this cryogenic storage tank evaporation rate test system. The dew point of the gas in the pipeline of this cryogenic storage tank evaporation rate test system is measured with a dew point meter. The dew point index is -53.4℃.

[0046] The specific steps of the air pressure and air tightness test are as follows: Seal the inlet and outlet of the pipeline of the cryogenic storage tank evaporation rate test system, open the third valve 81, and charge nitrogen into the cryogenic storage tank evaporation rate test system from the purge port 82. Then close the third valve 81 and maintain the pressure for 30 minutes. When the pressure sensor 62 detects that the preset pressure value in the pipeline (in the technical solution provided in the embodiment of this application, the preset pressure value is less than 0.3MPa) remains unchanged, it indicates that the cryogenic storage tank evaporation rate test system meets the air tightness requirements.

[0047] The cryogenic storage tank evaporation rate testing system provided in this application embodiment also includes a sampling pipeline 52 and a fourth valve 53; one end of the sampling pipeline 52 is connected to the venting pipeline 5, and the other end is provided with a sampling port 54; the fourth valve 53 is connected to the sampling pipeline 52 and is used to control the on / off state of the sampling pipeline 52.

[0048] It should be noted that when using this cryogenic storage tank evaporation rate testing system to test the evaporation rate of liquid hydrogen storage tanks, the oxygen content in the pipeline must be less than or equal to 0.4%. The specific steps for detecting the oxygen content of the testing system are as follows: open the third valve 81 and the fourth valve 53, use nitrogen gas to continuously purge through the purge port 82, set the oxygen concentration analyzer at the sampling port 54 to detect the oxygen content of the gas flowing out of the sampling port 54, and only after the oxygen concentration analyzer detects that the oxygen content is less than or equal to 0.4% can this cryogenic storage tank evaporation rate testing system be used to test the evaporation rate of liquid hydrogen storage tanks.

[0049] The cryogenic storage tank evaporation rate testing system provided in this application embodiment also includes a grounding terminal 9, which is electrically connected to the exhaust pipe 3 or the vent pipe 5. It is readily understood that grounding the cryogenic storage tank evaporation rate testing system via the grounding terminal 9 can protect operators from electric shock and other hazards, eliminate static electricity or electromagnetic interference generated during equipment operation, reduce the impact of the external environment on the testing system, and improve the accuracy and reliability of the evaporation rate test.

[0050] Figure 2 A flowchart illustrating a method for testing the evaporation rate of a cryogenic storage tank according to an embodiment of this application is shown. The method for testing the evaporation rate of a cryogenic storage tank includes the following steps: S1. Close the first valve 41, and connect the liquid outlet line 1 and the vent line 5 through the exhaust line 3. S2. The liquid outlet pipe 1 is connected to the cryogenic storage tank, and the liquid medium flowing out of the liquid outlet pipe 1 is vaporized into a gaseous medium through the reheater 2. S3. The gaseous medium is released through exhaust pipe 3 and vent pipe 5 until the gauge pressure of the cryogenic storage tank returns to zero. S4. Open the first valve 41 to connect the liquid outlet line 1 and the vent line 5 through the test line 4. S5. Use the test components to detect the state information of the gaseous medium in test pipeline 4; S6. Calculate the evaporation rate based on the detected state information of the gaseous medium.

[0051] Step S1 specifically includes: closing the first valve 41 so that gas cannot flow from one end of the test pipeline 4 to the other end of the test pipeline 4; opening the second valve 31 so that the liquid outlet pipeline 1 and the vent pipeline 5 are connected through the exhaust pipeline 3, and the gas can flow along the liquid outlet pipeline 1, the exhaust pipeline 3 and the vent pipeline 5 to the vent port 51.

[0052] Step S2 specifically includes: the connection part 11 of the liquid outlet pipe 1 is connected to the liquid outlet valve of the pipe outlet of the cryogenic storage tank, and the liquid medium in the cryogenic storage tank can flow out along the liquid outlet pipe 1 to the reheater 2. The reheater 2 heats the liquid medium, so that the liquid medium entering the reheater 2 vaporizes into a gaseous medium and flows out from the other end of the reheater 2.

[0053] Step S3 specifically includes: slightly opening the outlet valve of the cryogenic storage tank, closely monitoring the hydrogen emission, using a hydrogen concentration alarm to detect the hydrogen concentration at the test site to prevent liquid hydrogen or hydrogen leakage, and fully opening the outlet valve of the cryogenic storage tank after the gauge pressure of the cryogenic storage tank returns to zero, the airflow decreases, and the frost on the pipeline no longer continues to increase.

[0054] Step S4 specifically includes: opening the first valve 41, connecting the liquid outlet pipeline 1 and the vent pipeline 5 through the test pipeline 4, and closing the second valve 31 so that the gaseous medium cannot flow into the vent pipeline 5 through the exhaust pipeline 3.

[0055] Step S5 specifically includes: using flow meter 61 to detect the flow rate in test pipeline 4, using pressure sensor 62 to detect the pressure in test pipeline 4, using temperature sensor 63 to detect the temperature in test pipeline 4, using ambient temperature sensor 64 to detect the ambient temperature, and using atmospheric pressure sensor 65 to detect the ambient atmospheric pressure.

[0056] Step S6 specifically includes: setting parameters for the recorder 7, selecting hydrogen as the medium, setting the acquisition interval to no more than 1 hour, and recording data detected by the flow meter 61, pressure sensor 62, temperature sensor 63, ambient temperature sensor 64, and atmospheric pressure sensor 65 for 24 hours. The test evaporation rate and static evaporation rate of the cryogenic storage tank are calculated using the data collected by the recorder 7, and the calculated static evaporation rate is compared with the static evaporation rate of the previous 24 hours. When the variation range of the static evaporation rate is less than 5%, the recorded data and the calculated test evaporation rate are valid; when the variation range of the static evaporation rate is greater than 5%, data can be re-recorded once, with a re-recording time of no less than 24 hours, and this re-recorded data is the final recorded data.

[0057] The evaporation rate is calculated using the following formula: Where α0 is the test evaporation rate, in percentage per day (% / d); q m ψ is the daily average flow rate of the gas mass flow meter, expressed in kilograms per day (Kg / d); ψ is the calibration coefficient of the gas mass flow meter, a given value during calibration; ρ1 is the density of the saturated medium at standard atmospheric pressure (101.325 kPa); V is the effective volume of the container being measured, expressed in cubic meters. 3 .

[0058] The static evaporation rate is calculated using the following formula: Where, α 20 α0 is the static evaporation rate, expressed as a percentage per day (% / d); h is the test evaporation rate, expressed as a percentage per day (% / d); h is the latent heat of vaporization of the saturated medium under the test environment pressure, expressed as kilograms (kJ / kg). fg T represents the latent heat of vaporization of a saturated medium at standard atmospheric pressure (101.325 kPa), expressed in kilojoules per kilogram (kJ / kg). ST1 is the temperature of the saturated medium at standard atmospheric pressure (101.325 kPa), in Kelvin (K); T2 is the daily average ambient temperature during the test, in Kelvin (K); T3 is the saturated temperature of the cryogenic medium corresponding to the daily average pressure inside the test piece during the test, in Kelvin (K).

[0059] Although the invention has been described with reference to several typical embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Since the invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A cryogenic storage tank evaporation rate testing system, installed on a cryogenic storage tank, characterized in that, include: A liquid outlet pipeline, one end of which is connected to the cryogenic storage tank, is used to guide the liquid medium out of the cryogenic storage tank; A reheater, which is connected to the other end of the liquid outlet pipe, heats and vaporizes the liquid medium flowing out of the liquid outlet pipe to form a gaseous medium; An exhaust pipe, one end of which is connected to the reheater; A test pipeline, one end of which is connected to the regenerator, and the test pipeline and the exhaust pipeline are connected in parallel; A first valve, which is connected to the test pipeline, is used to control the on / off state of the test pipeline; The venting pipeline has one end connected to the end of the test pipeline away from the regenerator and the end of the exhaust pipeline away from the regenerator, and the other end is provided with a venting port. The testing component is used to detect the state information of the gaseous medium inside the testing pipeline.

2. The cryogenic storage tank evaporation rate testing system according to claim 1, characterized in that, The cryogenic storage tank is used to load liquid hydrogen, and the testing component is used to detect the state information of hydrogen in the testing pipeline.

3. The cryogenic storage tank evaporation rate testing system according to claim 1, characterized in that, It also includes a recorder, which is communicatively connected to the test component.

4. The cryogenic storage tank evaporation rate testing system according to claim 3, characterized in that, The recorder is equipped with a communication module, which is used to communicate with external network devices to upload the data recorded by the recorder to the external network devices.

5. The cryogenic storage tank evaporation rate testing system according to claim 3, characterized in that, It also includes an explosion-proof control box, and the recorder is located inside the explosion-proof control box.

6. The cryogenic storage tank evaporation rate testing system according to claim 1, characterized in that, The test components include a flow meter, a pressure sensor, a temperature sensor, an ambient temperature sensor, and an atmospheric pressure sensor. The flow meter, pressure sensor, and temperature sensor are all connected to the test pipeline and are located downstream of the first valve. The flow meter, pressure sensor, and temperature sensor are used to detect the flow rate, pressure, and temperature in the test pipeline, respectively. The ambient temperature sensor and atmospheric pressure sensor are used to detect the ambient temperature and atmospheric pressure, respectively.

7. The cryogenic storage tank evaporation rate testing system according to claim 1, characterized in that, It also includes a second valve, which is connected to the exhaust pipe and is used to control the opening and closing of the exhaust pipe.

8. The cryogenic storage tank evaporation rate testing system according to claim 1, characterized in that, It also includes a purge pipeline and a third valve; one end of the purge pipeline is connected to the liquid outlet pipeline, and the other end is provided with a purge port; the third valve is connected to the purge pipeline and is used to control the on / off state of the purge pipeline.

9. The cryogenic storage tank evaporation rate testing system according to claim 1, characterized in that, The liquid outlet pipeline includes a connecting part and a flexible pipeline. The connecting part is provided at both ends of the flexible pipeline. The two ends of the liquid outlet pipeline are connected to the cryogenic storage tank and the reheater through the connecting part, respectively.

10. The cryogenic storage tank evaporation rate testing system according to claim 1, characterized in that, It also includes a sampling pipeline and a fourth valve; one end of the sampling pipeline is connected to the venting pipeline, and the other end is provided with a sampling port; the fourth valve is connected to the sampling pipeline and is used to control the on / off state of the sampling pipeline.

11. The cryogenic storage tank evaporation rate testing system according to claim 1, characterized in that, It also includes a grounding terminal, which is electrically connected to the exhaust pipe or vent pipe.

12. A method for testing the evaporation rate of a low-temperature storage tank, characterized in that, The method for testing the evaporation rate of cryogenic storage tanks is applicable to the cryogenic storage tank evaporation rate testing system according to any one of claims 1-11, and includes the following steps: The first valve is closed, and the liquid outlet pipeline and the vent pipeline are connected through the exhaust pipeline; The liquid outlet pipeline is connected to the cryogenic storage tank, and the liquid medium flowing out of the liquid outlet pipeline is vaporized into a gaseous medium through the reheater; The gaseous medium is released through the exhaust pipe and the vent pipe until the gauge pressure of the cryogenic storage tank returns to zero; Open the first valve to connect the liquid outlet line and the vent line through the test line; The state information of the gaseous medium in the test pipeline is detected using the test component. The evaporation rate is calculated based on the detected state information of the gaseous medium.

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