Cryogenic fluid supply system

Abstract

The invention relates to the technical field of spaceflight tests, and discloses a low-temperature fluid supply system which comprises a refrigeration module comprising a refrigeration medium storage part suitable for containing a liquid refrigeration medium; the heat exchange assembly comprises a heat exchange cavity and a heat exchange pipeline, the heat exchange cavity is suitable for being communicated with the atmosphere, the refrigerating medium storage part is communicated with the heat exchange cavity so as to introduce a liquid refrigerating medium into the heat exchange cavity or discharge the liquid refrigerating medium from the heat exchange cavity, and the heat exchange pipeline is arranged in the heat exchange cavity; and the fluid supply module comprises a fluid storage part, the fluid storage part communicates with one end of the heat exchange pipeline, and the other end of the heat exchange pipeline communicates with a main drainage pipeline. The heat exchange area is dynamically adjusted by adjusting the liquid level of the liquid refrigerating medium in the heat exchange cavity, and continuous control over the temperature of output fluid within a wide range is achieved. As the heat exchange cavity is communicated with the atmosphere, the temperature is stable and is not influenced by air pressure fluctuation in the cavity, and long-term stability of the temperature of output fluid is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of aerospace testing technology, and more specifically to a cryogenic fluid supply system. Background Technology

[0002] In the aerospace field, particularly in the research and development and ground testing of liquid rocket engines, it is often necessary to supply cryogenic gas at specific temperatures and flow rates during ground simulation tests to verify the performance and reliability of engine pipelines, valves, and other components in extreme cryogenic environments. This is to complete the pre-cooling characteristic test of the engine system. The test requires the gas supply system to provide gas at a pressure higher than the required pressure, with a temperature that can be precisely set and maintained stably over a wide cryogenic range. Its temperature regulation range is typically from 22K to 273K, covering the cryogenic region to near room temperature.

[0003] In existing technologies, cryogenic gases typically use cryogenic liquids such as liquid hydrogen as a cold source. Liquid hydrogen stored in a cryogenic container is drawn out and vaporized in a carburetor to undergo a phase change, transforming it into gaseous hydrogen. This gas is then piped to the engine under test. Cryogenic gas supply relies on adjusting the heat load or flow rate of the carburetor to attempt to control the outlet gas temperature, and pressure and flow are regulated using components such as pressure reducing valves and flow meters. However, with direct phase change heat transfer, the outlet gas temperature is affected by a combination of factors, including the liquid hydrogen saturation temperature, the stability of the vaporization process, and environmental heat infiltration, making rapid, precise adjustment and long-term stable control difficult. Furthermore, the phase change process itself is unstable due to environmental pressure, and fluctuations in environmental heat flow cause the supply temperature to drift, making it difficult to meet the stringent long-term temperature stability requirements of engine pre-cooling tests. Summary of the Invention

[0004] This invention provides a cryogenic fluid supply system to solve the problem of large temperature error range in the supply of cryogenic gas in existing aerospace test systems.

[0005] In a first aspect, the present invention provides a cryogenic fluid supply system, comprising: A refrigeration module, comprising a refrigeration medium storage container adapted to contain a liquid refrigeration medium; A heat exchange assembly includes a heat exchange chamber and heat exchange piping. The heat exchange chamber is adapted to communicate with the atmosphere. A refrigerant storage device is connected to the heat exchange chamber to introduce liquid refrigerant into the heat exchange chamber or to discharge liquid refrigerant from the heat exchange chamber. The heat exchange piping is disposed inside the heat exchange chamber. A fluid supply module includes a fluid storage device connected to one end of the heat exchange pipeline, and the other end of the heat exchange pipeline connected to a drain main. The refrigerant storage device is adapted to controllably transport the liquid refrigerant from the refrigerant storage device to the heat exchange chamber, or controllably return the liquid refrigerant from the heat exchange chamber to the refrigerant storage device, so as to adjust the heat exchange area between the heat exchange pipeline and the liquid refrigerant by changing the liquid level in the heat exchange chamber, thereby regulating the fluid temperature output from the drain main.

[0006] The cryogenic fluid supply system controls the flow of liquid refrigerant from and out of the heat exchange chamber of the heat exchange component via a refrigerant storage unit in the refrigeration module, thereby altering the liquid level of the refrigerant within the chamber. Since the heat exchange piping is located within the chamber, changes in liquid level directly alter the effective heat exchange area between the piping and the liquid refrigerant. The fluid to be cooled flows from the fluid storage unit in the fluid supply module, undergoes heat exchange through the heat exchange piping, and is then output from the drain line. By controlling the rise and fall of the liquid refrigerant level within the heat exchange chamber, the temperature of the output fluid can be regulated. Dynamically adjusting the heat exchange area by regulating the liquid refrigerant level within the chamber allows for continuous and precise control of the output fluid temperature over a wide range. Furthermore, because the heat exchange chamber is open to the atmosphere, the liquid refrigerant within maintains its saturation temperature at atmospheric pressure, ensuring temperature stability unaffected by pressure fluctuations and guaranteeing long-term stability of the output fluid temperature.

[0007] In one optional embodiment, the refrigeration module further includes a driving gas storage device, which is adapted to contain refrigerant driving gas. The driving gas storage device and the refrigerant storage device are connected through a pressurization pipeline, and a pressurization control valve is installed on the pressurization pipeline. The refrigerant storage device is connected to a first venting pipe, which is connected to the atmosphere, and a first venting control valve is installed on the first venting pipe.

[0008] The driving gas storage unit supplies refrigerant driving gas to the refrigerant storage unit through a pressurization pipeline. The pressure inside the refrigerant storage unit is regulated by controlling the opening and closing of the pressurization control valve. Simultaneously, by controlling the opening and closing of the first vent control valve, the gas inside the refrigerant storage unit can be discharged to the atmosphere through the first vent pipeline, thereby reducing the pressure inside the refrigerant storage unit. Through the cooperation of the pressurization control valve and the first vent control valve, the pressure inside the refrigerant storage unit can be regulated, thereby controlling the delivery of liquid refrigerant to or from the heat exchange chamber and achieving stable regulation of the liquid refrigerant level in the heat exchange chamber.

[0009] In one optional embodiment, the lowest point of the inner cavity of the refrigerant storage device is not higher than the lowest point of the inner cavity of the heat exchange chamber, and a filling and draining pipeline is connected between the bottom of the refrigerant storage device and the bottom of the heat exchange chamber, and a filling and draining control valve is installed on the filling and draining pipeline.

[0010] The refrigerant reservoir is located below the heat exchange chamber, connected to its bottom via a charging / return line. When the charging / return control valve is opened, the liquid refrigerant flows from the chamber to the refrigerant reservoir for heat exchange under its own weight, or is transported from the refrigerant reservoir to the heat exchange chamber under pressure applied by the refrigerant-driven gas. The height difference between the refrigerant reservoir and the heat exchange chamber, combined with the charging / return line, allows the transport and return of the liquid refrigerant to be achieved solely through pressure difference or gravity, thus ensuring the stability of the liquid level control within the heat exchange chamber.

[0011] In one optional embodiment, a connecting pipe is provided between the top of the refrigerant storage container and the top of the heat exchange chamber, and a connecting control valve is installed on the connecting pipe. When the liquid refrigerant returns from the heat exchange chamber to the refrigerant storage container, the connection control valve opens and the first vent control valve closes to prevent air from entering the heat exchange chamber and the refrigerant storage container, thus ensuring the safety of the heat exchange chamber and the refrigerant storage container.

[0012] When the connecting control valve is open, the top of the refrigerant reservoir and the top of the heat exchange chamber are connected via a connecting pipe, causing the air cushion pressures in both to tend to equalize. When the connecting control valve is closed, the air cushion pressures in the refrigerant reservoir and the heat exchange chamber can be adjusted independently. The connecting pipe and the connecting control valve work together to achieve pressure balance between the refrigerant reservoir and the heat exchange chamber, preventing unexpected flow of the liquid refrigerant due to pressure differences, improving the stability and safety of system operation, and helping to maintain a constant temperature of the liquid refrigerant in the heat exchange chamber.

[0013] In one alternative implementation, multiple sets of the heat exchange pipelines are installed in parallel within the heat exchange chamber.

[0014] Multiple sets of heat exchange pipelines are connected in parallel within the heat exchange chamber, and each set of heat exchange pipelines can be independently supplied with fluid. By controlling the opening and closing of each set of heat exchange pipelines, the effective heat exchange area can be adjusted or different fluid flow rates can be accommodated. When the temperature of the supply fluid output from the drain main cannot meet the required low temperature, the supply fluid output from the fluid storage device is divided into multiple groups by opening multiple sets of parallel heat exchange pipelines. Each group of supply fluid enters a different heat exchange pipeline, obtains cooling capacity from the heat exchange chamber to cool down to the predetermined temperature, and then converges back into the drain main for common output, thereby meeting the user's demand for low-temperature supply fluid.

[0015] In one optional embodiment, a second venting pipe is connected to the heat exchange chamber, the second venting pipe is connected to the atmosphere, and a second venting control valve is installed on the second venting pipe; When the liquid refrigerant returns from the heat exchange chamber to the refrigerant storage container, the second vent control valve closes to prevent air from being drawn back into the heat exchange chamber from the second vent pipeline. If air enters the heat exchange chamber, it will mix with liquid hydrogen to form a flammable and explosive mixture, posing a serious safety hazard. Therefore, when opening the second vent valve, it is essential to ensure that the air pressure in the heat exchange chamber is greater than the real-time ambient air pressure.

[0016] The second vent pipe is connected to the top of the heat exchange chamber. By opening or closing the second vent control valve, the gas inside the heat exchange chamber can be connected to or isolated from the atmosphere, thereby maintaining the pressure inside the heat exchange chamber consistent with the ambient atmospheric pressure. This keeps the liquid refrigerant at its saturation temperature under atmospheric pressure, avoiding the impact of pressure fluctuations on the temperature of the liquid refrigerant, and thus ensuring the stability of the liquid refrigerant temperature.

[0017] In one optional embodiment, a main flow supply line is connected between the fluid storage device and the heat exchange pipeline, and a pressure reducer and a flow control nozzle are installed on the main flow supply line, with the flow control nozzle installed downstream of the pressure reducer.

[0018] After the fluid to be cooled flows out of the fluid reservoir, it passes sequentially through a pressure reducer and a flow control nozzle. The pressure reducer lowers the fluid pressure to a set value, while the flow control nozzle, based on its inherent characteristics, stabilizes the fluid flow rate at a constant value before the fluid enters the heat exchange pipeline. The combination of the pressure reducer and the flow control nozzle enables precise regulation of the fluid pressure and constant control of the flow rate, ensuring that the fluid flow rate entering the heat exchange pipeline is not affected by upstream pressure fluctuations.

[0019] In one alternative embodiment, a pressure monitoring element is installed between the pressure reducer and the flow control nozzle.

[0020] A pressure monitoring device is installed on the pipeline between the pressure reducer and the flow control nozzle to monitor the fluid pressure at that location in real time and feed the pressure signal back to the control system. This allows the operator or control system to precisely adjust the pressure reducer based on the readings from the pressure monitoring device, thereby ensuring stable pressure before the flow control nozzle and further guaranteeing the accuracy of flow control.

[0021] In one optional embodiment, a temperature monitoring device is installed on the drain bus. The temperature of the fluid flowing from the heat exchange pipes and into the drain bus is monitored in real time. This allows operators or the control system to adjust the liquid refrigerant level in the heat exchange chamber promptly based on the temperature monitoring device readings, thereby achieving precise control and long-term stability of the output fluid temperature.

[0022] In one optional embodiment, a first level gauge is installed in the refrigerant storage container to measure the liquid level of the liquid refrigerant in the refrigerant storage container; and / or, a second level gauge is installed in the heat exchange chamber to measure the liquid level of the liquid refrigerant in the heat exchange chamber. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a cryogenic fluid supply system according to an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached drawings: 1. Refrigerant storage unit; 2. First level gauge; 3. Heat exchange chamber; 4. Second level gauge; 5. Heat exchange pipeline; 6. Fluid storage unit; 7. Main supply line; 8. Supply control valve; 9. Pressure reducer; 10. Flow control nozzle; 11. Pressure monitoring device; 12. Supply branch pipe; 13. Branch pipe control valve; 14. Drain main line; 15. Drain branch pipe; 16. Temperature monitoring device; 17. Drive gas storage unit; 18. Pressurization line; 19. Pressurization control valve; 20. First vent line; 21. First vent control valve; 22. Filling and returning line; 23. Filling and returning control valve; 24. Connecting line; 25. Connecting control valve; 26. Second vent line; 27. Second vent control valve. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The following is combined Figure 1 The following describes embodiments of the present invention.

[0028] According to embodiments of the present invention, a cryogenic fluid supply system is provided, including a refrigeration module, a heat exchange component, and a fluid supply module. The modules are connected via pipelines and valves to jointly achieve a constant temperature and flow rate supply of cryogenic fluid. Specifically: The refrigeration module includes a refrigerant storage unit 1, which stores liquid refrigerants such as liquid hydrogen or liquid nitrogen. The heat exchange assembly includes a heat exchange chamber 3 and heat exchange pipes 5 disposed inside the heat exchange chamber 3. The top of the heat exchange chamber 3 has an opening or pipe communicating with the atmosphere, ensuring that the pressure of the gas cushion inside the heat exchange chamber 3 remains consistent with the ambient atmospheric pressure. The refrigerant storage unit 1 is connected to the heat exchange chamber 3 via a pipe at the bottom. The fluid supply module includes a fluid storage unit 6, which stores gases such as hydrogen or helium at room temperature to be cooled. The fluid storage unit 6 is connected to one end of the heat exchange pipes 5 via a gas supply pipe, and the other end of the heat exchange pipes 5 converges to a drain main 14, through which the cooled gas is discharged.

[0029] By controlling the refrigeration module, liquid refrigerant can be purposefully transported from the refrigerant storage unit 1 to the heat exchange chamber 3, or recovered from the heat exchange chamber 3 back to the refrigerant storage unit 1. The transport and recovery processes can change the liquid level of the refrigerant in the heat exchange chamber 3. Since the heat exchange pipe 5 is submerged or partially submerged in the liquid refrigerant in the heat exchange chamber 3, changes in the liquid level will correspondingly alter the effective area for heat exchange between the outer wall of the heat exchange pipe 5 and the liquid refrigerant. When the fluid to be cooled from the fluid storage unit 6 flows through the heat exchange pipe 5, it is cooled by exchanging heat with the constant-temperature liquid refrigerant in the heat exchange chamber 3. Finally, the cooled fluid is output to the required equipment or process stage via the drain main 14.

[0030] By adjusting the liquid refrigerant level within the heat exchange chamber 3, and thus controlling the heat exchange area, the temperature of the fluid at the outlet of the drain main 14 can be effectively regulated, enabling continuous and stable control of the fluid at the outlet of the drain main 14 over a relatively wide temperature range. Since the heat exchange chamber 3 remains open to the atmosphere, the liquid refrigerant within it is always at its saturation temperature under its corresponding atmospheric pressure. This ensures that the cold source temperature itself remains stable, unaffected by occasional fluctuations in internal system pressure, thereby guaranteeing long-term stability of the output fluid temperature. It also avoids temperature errors in the output fluid of the drain main 14 caused by changes in the liquid refrigerant temperature within the heat exchange chamber 3 due to pressure variations during fluid supply.

[0031] In one embodiment, the refrigeration module further includes a driving gas storage unit 17, which forms a sealed containment space for storing high-pressure refrigerant driving gas. The driving gas storage unit 17 can be in the form of a high-pressure gas cylinder, storage tank, or other pressure vessel, and the material must meet pressure resistance and media compatibility requirements. The driving gas storage unit 17 is connected to the refrigerant storage unit 1 via a pressurization pipeline 18, with both ends of the pressurization pipeline 18 sealed and connected to the outlet of the driving gas storage unit 17 and the inlet at the top of the refrigerant storage unit 1, respectively. A pressurization control valve 19 is installed on the pressurization pipeline 18. The pressurization control valve 19 can be a solenoid valve, pneumatic valve, or manual valve, and its on / off state and opening degree adjustment are automatically controlled by the control system based on the pressure feedback signal from the refrigerant storage unit 1.

[0032] Furthermore, a first venting pipe 20 is connected to the top side wall or top cover of the refrigerant storage container 1. One end of the first venting pipe 20 is connected to the gas phase space inside the refrigerant storage container 1, and the other end is directly connected to the atmospheric environment. A first venting control valve 21 is installed on the first venting pipe 20. The first venting control valve 21 can also be in the form of a solenoid valve, a safety valve, or a manual valve. The opening pressure of the first venting control valve 21 can be set to a safety threshold slightly higher than atmospheric pressure.

[0033] The driving gas storage unit 17 supplies refrigerant driving gas to the refrigerant storage unit 1 through the pressurization pipeline 18. The pressure level of the gas cushion space inside the refrigerant storage unit 1 is precisely regulated by controlling the opening and closing timing and opening degree of the pressurization control valve 19. Simultaneously, by controlling the opening and closing of the first venting control valve 21, excess gas accumulated inside the refrigerant storage unit 1 can be safely discharged into the atmosphere through the first venting pipeline 20, thereby effectively reducing the pressure value inside the refrigerant storage unit 1. Through the coordinated and alternating operation of the pressurization control valve 19 and the first venting control valve 21, the internal gas pressure of the refrigerant storage unit 1 can be regulated and stabilized, thereby controlling the delivery rate of liquid refrigerant to or from the heat exchange chamber 3, and ultimately achieving stable regulation of the liquid refrigerant level within the heat exchange chamber 3.

[0034] In one embodiment, the horizontal plane of the lowest point of the inner cavity of the refrigerant storage 1 is not higher than the horizontal plane of the lowest point of the inner cavity of the heat exchange chamber 3. The bottom outlet of the refrigerant storage 1 and the bottom inlet of the heat exchange chamber 3 are connected by a filling and draining pipe 22. The filling and draining pipe 22 is made of low-temperature resistant and pressure-resistant metal pipe or composite pipe, and the pipe diameter is calculated and determined according to the required medium flow rate. A filling and draining control valve 23 is installed on the filling and draining pipe 22. The filling and draining control valve 23 can be a low-temperature solenoid valve, a low-temperature ball valve, or a low-temperature shut-off valve, etc.

[0035] The refrigerant storage unit 1 is spatially located directly below or to the side of the heat exchange chamber 3, and the bottom of the two are connected by a filling and draining pipe 22. When it is necessary to lower the liquid level in the heat exchange chamber 3, the filling and draining control valve 23 is opened, and the liquid refrigerant in the heat exchange chamber 3 will naturally flow back to the refrigerant storage unit 1 through the filling and draining pipe 22 under its own gravity. When it is necessary to raise the liquid level in the heat exchange chamber 3, under the pressure of the pressurized gas provided by the driving gas storage unit 17, the liquid refrigerant in the refrigerant storage unit 1 will be forced to flow through the filling and draining pipe 22 into the heat exchange chamber 3. The height difference design between the refrigerant storage unit 1 and the heat exchange chamber 3, combined with the filling and draining pipe 22, allows the forward delivery and reverse return of the liquid refrigerant to be achieved by pressure difference drive or its own gravity, without the need for additional power equipment such as a delivery pump or return pump, thereby ensuring the stability and reliability of the liquid level control process in the heat exchange chamber 3.

[0036] In this embodiment, the top gas phase space of the refrigerant storage unit 1 and the top gas phase space of the heat exchange chamber 3 are connected by a connecting pipe 24. A connecting control valve 25 is installed on the connecting pipe 24. The connecting control valve 25 can be a two-position two-way solenoid valve, a pneumatic valve, or a manual valve. The sealing performance of the connecting control valve 25 must meet the requirements to prevent gas leakage. To facilitate feedback regulation of the gas pressure inside the refrigerant storage unit 1, a pressure sensor is also installed on the refrigerant storage unit 1 to monitor the gas pressure inside the refrigerant storage unit 1 in real time and feed it back to the control system.

[0037] When it is necessary to lower the liquid level in heat exchange chamber 3, the connecting control valve 25 opens upon receiving an opening command from the control system. The gas phase space at the top of the refrigerant storage unit 1 and the gas phase space at the top of heat exchange chamber 3 are directly connected via the connecting pipe 24, and the pressure of the gas pillows in the two chambers quickly reaches equilibrium. When it is necessary to raise the liquid level in heat exchange chamber 3, the connecting control valve 25 closes the pipe upon receiving a closing command, isolating the pressure of the gas pillows in refrigerant storage unit 1 and heat exchange chamber 3, allowing for independent adjustment. The combined use of the connecting pipe 24 and the connecting control valve 25 achieves pressure balance between refrigerant storage unit 1 and heat exchange chamber 3, effectively preventing unexpected automatic flow of the liquid refrigerant due to pressure differences between the two chambers, thus improving the stability and safety of the system operation. Simultaneously, the connecting pipe 24 helps maintain the liquid refrigerant in heat exchange chamber 3 at atmospheric pressure, preventing temperature fluctuations caused by changes in gas pillow pressure.

[0038] In one embodiment, multiple sets of heat exchange pipes 5 are installed in parallel within the heat exchange chamber 3. Each set of heat exchange pipes 5 is sealed at both ends to the inlet of the main supply line 7 and the inlet of the main drainage line 14, respectively. The multiple sets of heat exchange pipes 5 are arranged in a matrix or concentric circles within the heat exchange chamber 3, and the outer wall of each set of heat exchange pipes 5 is in direct contact with the liquid refrigerant within the heat exchange chamber 3. The specific number of heat exchange pipes 5 can be calculated and determined based on the system's maximum design flow rate and the flow capacity of a single set of pipes; generally, 2 to 8 sets of parallel branch pipes are installed.

[0039] Each heat exchange pipeline 5 is equipped with an independent on / off valve at its inlet or outlet. The on / off valve can be a solenoid valve, a pneumatic valve, or a manual valve. The on / off state of the valve is switched and controlled by the control system according to the actual operating conditions. Multiple heat exchange pipelines 5 are connected in parallel in the heat exchange chamber 3, and each heat exchange pipeline 5 can be independently supplied with fluid without interfering with each other.

[0040] By controlling the opening and closing of the on / off valves on each group of heat exchange pipelines 5, the total heat exchange area participating in the heat exchange process can be flexibly adjusted, and it can also adapt to the supply fluid of different flow ranges. When the temperature of the supply fluid output from the drain main 14 cannot meet the required low temperature, the control system will issue a command to open multiple groups of parallel heat exchange pipelines 5. The supply fluid output from the fluid storage device 6 is distributed into multiple branches, each branch entering a different heat exchange pipeline 5. Each branch synchronously acquires cooling energy in the heat exchange chamber 3 and is cooled to the predetermined temperature before re-merging into the drain main 14 for common output, thereby meeting the user's demand for a lower temperature supply fluid. The multiple groups of heat exchange pipelines 5 can also adopt different pipe diameter designs to adapt to a wider range of flow rate changes.

[0041] In one embodiment, a second vent pipe 26 is connected to the top side wall or top cover of the heat exchange chamber 3. One end of the second vent pipe 26 is connected to the gas phase space inside the heat exchange chamber 3, and the other end is directly connected to the atmospheric environment. A second vent control valve 27 is installed on the second vent pipe 26. The second vent control valve 27 can be a solenoid valve, a safety valve, or a manual valve.

[0042] The second vent pipe 26 is connected to the top of the heat exchange chamber 3. By manually or automatically controlling the opening or closing of the second vent control valve 27, the gas inside the heat exchange chamber 3 can be connected to or isolated from the atmospheric environment. This maintains that the pressure inside the heat exchange chamber 3 remains consistent with the ambient atmospheric pressure during fluid supply. This ensures that the liquid refrigerant inside the heat exchange chamber 3 is always at its saturation temperature under atmospheric pressure, effectively avoiding the adverse effects of internal system pressure fluctuations on the liquid refrigerant temperature and guaranteeing the long-term stability of the liquid refrigerant temperature.

[0043] When the cryogenic medium flows back from heat exchange chamber 3 to the refrigerant storage unit 1 via gravity, the second vent control valve 27 must be closed. Otherwise, air will be drawn back into heat exchange chamber 3 through the second vent pipe 26. Once the air is drawn into heat exchange chamber 3, it will mix with liquid hydrogen to form a flammable and explosive mixture, causing a safety accident. At the same time, to prevent air from entering the refrigerant storage unit 1 through the first vent pipe 20, the first vent control valve 21 is also closed when the cryogenic medium flows back from heat exchange chamber 3 to the refrigerant storage unit 1 via gravity. The air pressure in the respective air cushions in the heat exchange chamber and the refrigerant storage unit is adjusted through the connecting pipe 24 to achieve the reflux of the cryogenic medium.

[0044] In one embodiment, the outlet of the fluid storage unit 6 is connected to the inlet of the heat exchange pipeline 5 via a main supply line 7. The main supply line 7 is made of pressure-resistant pipe, and its diameter is determined according to the design flow rate. A supply control valve 8 is installed upstream of the main supply line 7, and a pressure reducer 9 is installed downstream of the supply control valve 8. The pressure reducer 9 can be a diaphragm pressure reducer, a piston pressure reducer, or an electric pressure reducer. The outlet pressure adjustment range of the pressure reducer 9 must cover the system design pressure requirements. A flow control nozzle 10 is installed downstream of the main supply line 7. The flow control nozzle 10 can be a sonic nozzle, a critical flow venturi nozzle, or an orifice flow meter, etc. The flow coefficient of the flow control nozzle 10 must be calibrated. The installation position of the flow control nozzle 10 must be downstream of the pressure reducer 9 to ensure that the pressure reducer 9 can regulate the fluid pressure before the flow control nozzle 10.

[0045] After the fluid to be cooled flows out of the fluid reservoir 6, it flows sequentially through the pressure reducer 9 and the flow control nozzle 10 on the main supply line 7. The pressure reducer 9 lowers the fluid pressure to the target pressure value set by the system, while the flow control nozzle 10 uses its inherent critical flow or flow-limiting characteristics to stably control the fluid flow rate at a constant value. After pressure regulation and flow control, the fluid then enters the heat exchange pipeline 5 for cooling. The combined configuration of the pressure reducer 9 and the flow control nozzle 10 achieves the dual functions of precise regulation of fluid pressure and constant control of flow rate, ensuring that the fluid flow rate entering the heat exchange pipeline 5 is not affected by fluctuations in the outlet pressure of the fluid reservoir 6 or changes in the resistance of the main supply line 7.

[0046] Furthermore, to facilitate the connection between the main supply line 7 and multiple heat exchange pipelines 5, multiple supply branch pipes 12 are connected in parallel at the outlet end of the main supply line 7. Each supply branch pipe 12 is connected to a heat exchange pipeline 5 in a one-to-one correspondence, and a branch pipe control valve 13 is installed on each supply branch pipe 12. Similarly, to facilitate the connection between the main drainage line 14 and multiple heat exchange pipelines 5, multiple drainage branch pipes 15 are connected in parallel at the inlet end of the main drainage line. Each drainage branch pipe 15 is connected to a heat exchange pipeline 5 in a one-to-one correspondence.

[0047] In one embodiment, a pressure monitoring element 11 is installed on the main flow supply line 7 between the outlet of the pressure reducer 9 and the inlet of the flow control nozzle 10. The pressure monitoring element 11 is specifically installed close to the inlet of the flow control nozzle 10 to obtain the most accurate pressure data. The pressure monitoring element 11 can be in the form of a pressure sensor, pressure transmitter, or pressure gauge, etc., and the measurement accuracy of the pressure monitoring element 11 must meet the flow control accuracy requirements. The signal output terminal of the pressure monitoring element 11 is connected to the control system to monitor the fluid pressure value at the front end of the flow control nozzle 10 in the main flow supply line 7 in real time, and transmits the pressure signal back to the control system in real time.

[0048] Operators can observe the pressure value in real time through the monitoring interface, or enable the automatic control system to precisely adjust the opening of the pressure reducer 9 according to the pressure signal fed back by the pressure monitoring device 11 and the preset control algorithm, thereby ensuring that the pressure at the front end of the flow control nozzle 10 is always maintained near the target set value, further ensuring the accuracy and stability of flow control.

[0049] Furthermore, the pressure monitoring component 11 can also adopt a redundant design, installing two or three pressure sensors as backups for each other, thereby improving system reliability.

[0050] In one embodiment, a temperature monitoring element 16 is installed on the main pipe of the drain main 14. The installation location of the temperature monitoring element 16 should be selected on a pipe section where the fluid is fully mixed and far away from the outlet of the heat exchange pipe 5. The temperature monitoring element 16 can be a low-temperature platinum resistance temperature sensor, thermocouple, or fiber optic temperature sensor, etc. The measurement range and accuracy of the temperature monitoring element 16 must meet the temperature control requirements. The temperature monitoring element 16 monitors the actual temperature value of the fluid flowing out of the heat exchange pipe 5 and into the drain main 14 in real time, and transmits the temperature signal to the control system in real time.

[0051] Operators can monitor the temperature status of the output fluid in real time through the monitoring interface, or enable the control system to calculate and adjust the liquid level of the liquid refrigerant in the heat exchange chamber 3 in a timely manner based on the deviation between the reading of the temperature monitoring device 16 and the set value, thereby achieving precise closed-loop control and long-term stable maintenance of the output fluid temperature.

[0052] Similarly, the temperature monitoring device 16 can also adopt a multi-point measurement method, with multiple temperature sensors installed at different locations in the drain main 14, and the mixing uniformity of the fluid can be judged by comparing the temperatures at each point.

[0053] In one embodiment, a first level gauge 2 is installed on a conduit extending downward from the side wall or top inside the refrigerant storage container 1. The first level gauge 2 can be a differential pressure level gauge, a capacitive level gauge, or a float level gauge. The first level gauge 2 is used to continuously measure the real-time liquid level height of the liquid refrigerant stored in the refrigerant storage container 1 and transmit the liquid level signal to the control system.

[0054] Meanwhile, a second level gauge 4 is installed on the downward-extending conduit on the side wall or top inside the heat exchange chamber 3. The second level gauge 4 can also be of the differential pressure type, capacitive type or float type. The second level gauge 4 is used to continuously measure the current liquid level height of the liquid refrigerant in the heat exchange chamber 3 and feed the liquid level signal back to the control system in real time.

[0055] The configuration of level gauges enables the system to accurately monitor the medium levels in the two critical chambers, providing data support for precise level adjustment and also providing an over-limit alarm function for the safe operation of the system. The first level gauge 2 and the second level gauge 4 can also employ non-contact measurement methods such as radar level gauges or ultrasonic level gauges to avoid sealing and material problems caused by direct contact with the low-temperature medium.

[0056] In summary, the cryogenic gas constant temperature and constant flow supply system provided in this application operates as follows: First, liquid refrigerant is added to the heat exchange chamber 3 of the heat exchange component. At this time, the first venting control valve 21 is closed, the second venting control valve 27 is open, the filling return control valve 23 is opened to a suitable degree, the pressure boosting control valve 19 is opened, and the connecting control valve 25 is closed. The liquid refrigerant is squeezed from the refrigerant storage unit 1 into the heat exchange chamber 3, thereby raising the liquid level in the heat exchange chamber 3. The opening degree of the filling return control valve 23 controls the rate of liquid level rise.

[0057] When the fluid is needed: the flow control valve 8 is opened, the pressure regulator 9 is adjusted to adjust the reading of the pressure monitoring device 11 downstream of the pressure regulator 9, and then the pressure before the flow control nozzle 10 is adjusted to control the air supply flow rate. The air supply flow rate is equal to the reading of the pressure monitoring device 11 multiplied by the flow coefficient calibrated by the flow control nozzle 10. When the flow rate reaches the specific demand, the air supply is kept stable.

[0058] When it is necessary to lower the temperature of the supplied fluid, the liquid level in the heat exchange chamber 3 is continuously increased. This step of adding liquid refrigerant to the heat exchange chamber 3 of the heat exchange component continues until the temperature monitoring device 16 installed on the drain main 14 meets the requirements.

[0059] If the temperature of the supplied fluid is still not low enough, and the liquid level in heat exchange chamber 3 rises to the upper limit, and the temperature monitoring element 16 still does not meet the requirements, then the branch control valve upstream of a parallel heat exchange pipeline 5 is opened, allowing both heat exchange pipelines 5 to exchange heat synchronously in heat exchange chamber 3. If the temperature of the supplied fluid is still not low enough, more branch control valves upstream of parallel heat exchange pipelines 5 are opened.

[0060] When the temperature of the supplied fluid is low: the liquid level in the heat exchange chamber 3 can be regulated to decrease. When the first venting control valve 21 is closed, the second venting control valve 27 is closed, the filling and returning control valve 23 is open, the pressurization control valve 19 is closed, and the connecting control valve 25 is open, the cryogenic liquid flows from the heat exchange chamber 3 to the refrigerant storage unit 1 under the action of gravity, thus lowering the liquid level in the heat exchange chamber 3. The opening degree of the filling and returning control valve 23 controls the rate of liquid level decrease. After the liquid level drops to a specific level, the filling and returning control valve 23 is closed, the connecting control valve 25 is closed, the first venting control valve 21 is opened, and the second venting control valve 27 is closed.

[0061] By adjusting the liquid level of the liquid refrigerant in the heat exchange chamber 3 in real time according to the temperature of the supplied fluid, the outlet gas temperature of the exhaust main can be kept constant between 22K and 273K.

[0062] Furthermore, the refrigerant storage unit 1 stores liquid hydrogen or liquid nitrogen. If the exhaust gas temperature of the main exhaust line 14 is between 90K and 273K, the refrigerant storage unit 1 stores liquid nitrogen, and the gas stored in the driving gas storage unit 17 is high-pressure nitrogen.

[0063] The refrigeration medium storage unit 1 stores liquid hydrogen or liquid nitrogen. If the exhaust gas temperature of the main exhaust line 14 is between 25K and 90K, the refrigeration medium storage unit 1 stores liquid hydrogen, and the driving gas storage unit 17 stores high-pressure hydrogen or helium.

[0064] The refrigerant storage container 1 has a first level gauge inside to measure the liquid level. A pressure sensor on top of the refrigerant storage container 1 measures the pressure inside. The refrigerant storage container 1 is equipped with a pressurization system, which regulates the pressure inside the container by pressurizing, squeezing out the liquid. The pressurization system consists of a driving gas reservoir 17, a pressurization pipeline 18, and a pressurization control valve 19. A venting system is installed at the top of the refrigerant storage container 1, consisting of a first venting pipeline 21 and a first venting control valve 21. Opening the first venting control valve 21 reduces the pressure inside the refrigerant storage container 1, allowing it to reach a minimum pressure equal to atmospheric pressure. A filling and returning pipeline 22 and a filling and returning control valve 23 are installed at the bottom of the refrigerant storage container 1 to supply liquid from the refrigerant storage container 1 to the heat exchange chamber 3, and also to recover the cryogenic medium from the heat exchange chamber 3 back to the refrigerant storage container 1.

[0065] When the pressure inside the refrigerant storage 1 is too high, the booster control valve 19 is closed and the first vent control valve 21 is opened to release gas and reduce the pressure; when the pressure inside the refrigerant storage 1 is too low, the booster control valve 19 is opened and the first vent control valve 21 is closed to increase the pressure inside the refrigerant storage 1; through this process, the pressure inside the refrigerant storage 1 is controlled at the rated value.

[0066] The heat exchange assembly is used for heat exchange and cooling of gas and cryogenic liquid. The heat exchange assembly is a shell-and-tube type, including a heat exchange chamber 3 and heat exchange pipes 5. Gas flows through the tubes, and cryogenic liquid flows through the shell. The heat exchange assembly is vertical, with gas entering from the bottom and exiting from the top. A second vent pipe 26, a second vent control valve 27, and a check valve are installed at the top of the heat exchange assembly. A second level gauge 4 is installed inside the heat exchange assembly to measure the liquid level.

[0067] The heat exchange assembly is equipped with a set of heat exchange pipelines to adjust the heat exchange area. When the gas flow rate is low, only the branch control valve set at the upstream of one set of heat exchange pipelines is opened, and the other branch control valves are closed. When the temperature of the supplied gas cannot meet the requirements and it is necessary to reduce the temperature of the supplied gas, but the liquid level in the heat exchange chamber reaches the maximum, multiple sets of branch control valves are opened.

[0068] The heat exchange component and the refrigerant storage 1 are connected at the top by a connecting pipe 24. A connecting control valve 25 is installed on the connecting pipe 24 to balance the air cushion pressure between the heat exchange component and the refrigerant storage 1.

[0069] The liquid level inside the heat exchange assembly can be adjusted upwards. When the first venting control valve 21 is closed, the second venting control valve 27 is open, the filling and return control valve 23 is open, the pressure boosting control valve 19 is open, and the connecting control valve 25 is closed, cryogenic liquid is forced from the refrigerant storage unit 1 into the heat exchange assembly, thus raising the liquid level inside the heat exchange assembly. The opening degree of the filling and return control valve 23 controls the rate of liquid level rise.

[0070] The liquid level within the heat exchange assembly can be adjusted to decrease. When the first venting control valve 21 is closed, the second venting control valve 27 is closed, the charging and return control valve 23 is open, the pressurization control valve 19 is closed, and the connecting control valve 25 is open, the cryogenic liquid flows from the heat exchange assembly to the refrigerant storage container 1 under the influence of gravity, thus lowering the liquid level within the heat exchange assembly. The opening degree of the charging and return control valve 23 controls the rate of liquid level decrease.

[0071] The bottom of the heat exchange assembly is positioned above the top of the refrigerant storage container 1. At the rated gas flow rate requiring cooling, when the liquid level in the heat exchange assembly rises, the heat exchange area of ​​the heat exchange pipe 5 and the cryogenic medium increases, and the gas temperature at the outlet of the drain main 14 decreases. At the rated gas flow rate requiring cooling, when the liquid level in the heat exchange assembly drops, the heat exchange area of ​​the heat exchange pipe 5 and the cryogenic medium decreases, and the gas temperature at the outlet of the drain main 14 increases.

[0072] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cryogenic fluid supply system, characterized in that, include: A refrigeration module, comprising a refrigeration medium storage unit (1) adapted to contain a liquid refrigeration medium; A heat exchange assembly includes a heat exchange chamber (3) and a heat exchange pipeline (5). The heat exchange chamber (3) is adapted to communicate with the atmosphere. The refrigerant storage device (1) is connected to the heat exchange chamber (3) to introduce liquid refrigerant into the heat exchange chamber (3) or to discharge liquid refrigerant from the heat exchange chamber (3). The heat exchange pipeline (5) is located inside the heat exchange chamber (3). The fluid supply module includes a fluid storage device (6), which is connected to one end of the heat exchange pipeline (5), and the other end of the heat exchange pipeline (5) is connected to a drain main (14). The refrigerant storage unit (1) is adapted to controllably transport the liquid refrigerant from the refrigerant storage unit (1) to the heat exchange chamber (3), or controllably return the liquid refrigerant from the heat exchange chamber (3) to the refrigerant storage unit (1), so as to adjust the heat exchange area between the heat exchange pipeline (5) and the liquid refrigerant by changing the liquid level in the heat exchange chamber (3), thereby adjusting the fluid temperature output from the drain main (14).

2. The cryogenic fluid supply system according to claim 1, characterized in that, The refrigeration module also includes a driving gas storage unit (17), which is adapted to contain refrigerant driving gas. The driving gas storage unit and the refrigeration medium storage unit (1) are connected through a pressurization pipeline (18), and a pressurization control valve (19) is installed on the pressurization pipeline (18). The refrigerant storage device (1) is connected to a first venting pipe (20), which is connected to the atmosphere, and a first venting control valve (21) is installed on the first venting pipe (20).

3. The cryogenic fluid supply system according to claim 2, characterized in that, The lowest point of the inner cavity of the refrigerant storage (1) is not higher than the lowest point of the inner cavity of the heat exchange chamber (3), and a filling and draining pipeline (22) is connected between the bottom of the refrigerant storage (1) and the bottom of the heat exchange chamber (3), and a filling and draining control valve (23) is installed on the filling and draining pipeline (22).

4. The cryogenic fluid supply system according to claim 2 or 3, characterized in that, A connecting pipe (24) is connected between the top of the refrigerant storage (1) and the top of the heat exchange chamber (3), and a connecting control valve (25) is installed on the connecting pipe (24). When the liquid refrigerant returns from the heat exchange chamber (3) to the refrigerant storage container (1), the communication control valve (25) is opened.

5. The cryogenic fluid supply system according to any one of claims 1 to 3, characterized in that, Multiple sets of the heat exchange pipeline (5) are installed in parallel within the heat exchange chamber (3).

6. The cryogenic fluid supply system according to any one of claims 1 to 3, characterized in that, The heat exchange chamber (3) is connected to a second vent pipe (26), which is connected to the atmosphere. A second vent control valve (27) is installed on the second vent pipe (26). When the liquid refrigerant returns from the heat exchange chamber (3) to the refrigerant storage container (1), the second discharge control valve (27) is closed.

7. The cryogenic fluid supply system according to any one of claims 1 to 3, characterized in that, The fluid storage device (6) is connected to the heat exchange pipeline (5) by a main flow supply line (7), and a pressure reducer (9) and a flow control nozzle (10) are installed on the main flow supply line (7). The flow control nozzle (10) is installed downstream of the pressure reducer (9).

8. The cryogenic fluid supply system according to claim 7, characterized in that, A pressure monitoring device (11) is installed between the pressure reducer (9) and the flow control nozzle (10).

9. The cryogenic fluid supply system according to any one of claims 1 to 3, characterized in that, A temperature monitoring device (16) is installed on the main drainage channel (14).

10. The cryogenic fluid supply system according to any one of claims 1 to 3, characterized in that, A first level gauge (2) is installed in the refrigerant storage container (1), and / or a second level gauge (4) is installed in the heat exchange chamber (3).

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