A high-pressure hydrogen filling system and method based on liquid hydrogen pressurization

Abstract

This invention discloses a high-pressure gaseous hydrogen filling system based on liquid hydrogen pressurization, including a liquid hydrogen storage tank connected to the inlet of a liquid hydrogen vaporizer via a liquid hydrogen booster pump; a first outlet of the liquid hydrogen vaporizer connected to the liquid hydrogen storage tank via a gaseous hydrogen outlet bypass, the gaseous hydrogen outlet bypass being equipped with a gaseous hydrogen pressure reducing valve; and a second outlet of the liquid hydrogen vaporizer connected to a gaseous hydrogen container. The invention also discloses a high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization. By connecting a gaseous hydrogen outlet bypass from the liquid hydrogen vaporizer to the liquid hydrogen storage tank, this invention increases the pressure of the liquid hydrogen stored in the storage tank, thereby increasing the inlet pressure of the liquid hydrogen booster pump, thus increasing the booster pump's pressurization efficiency and improving the efficiency of high-pressure gaseous hydrogen filling.

Description

Technical Field

[0001] This invention relates to the field of hydrogen energy technology, and in particular to a high-pressure gaseous hydrogen filling system and method based on liquid hydrogen pressurization. Background Technology

[0002] Liquid hydrogen boasts advantages such as high storage density, high transportation efficiency, and safe low-pressure storage and transportation, making it an ideal method for large-scale hydrogen energy storage and transportation supply, and a key guarantee for the development of my country's hydrogen fuel cell vehicle industry. Liquid hydrogen refueling stations represent a significant development trend in the hydrogen refueling station sector. Based on the advantages of liquid hydrogen storage and transportation, liquid hydrogen storage and refueling stations offer advantages including low cost for large-scale construction, avoidance of high-pressure storage risks, low operating energy consumption, and strong expansion capabilities. Liquid hydrogen storage and refueling stations can adopt a technology route of pressurizing and then vaporizing liquid hydrogen to meet the refueling needs of high-pressure gaseous hydrogen. The mechanical power required for liquid hydrogen compression and pressurization is much less than that for gaseous hydrogen compression and pressurization; therefore, the combination of a liquid hydrogen booster pump and a liquid hydrogen vaporizer is the main technical route for liquid hydrogen storage and refueling stations. However, currently, the high-tech core equipment, such as the liquid hydrogen booster pump, is still in the prototype development stage in China. During testing of a small number of existing liquid hydrogen booster pump products, it was found that although the liquid hydrogen booster pumps are usable, they have strict requirements for the liquid inlet conditions. Lower liquid inlet pressure will result in low booster efficiency of the liquid hydrogen booster pump or even failure to reach the rated pressure value, thus making it impossible to complete the filling and refilling of high-pressure gaseous hydrogen.

[0003] The "Liquid Hydrogen Vaporization and Hydrogenation System" disclosed in Chinese patent literature, publication number CN217736920U, publication date 2022-11-04, includes a liquid hydrogen storage tank containing liquid hydrogen. Above the liquid hydrogen in the liquid hydrogen storage tank is hydrogen gas. The liquid hydrogen storage tank is connected to a hydrogen booster pump via a first pipe and to a liquid hydrogen pump via a second pipe. The first and second pipes are respectively connected to the hydrogen gas and liquid hydrogen in the liquid hydrogen storage tank. The hydrogen booster pump and liquid hydrogen pump are respectively connected to a liquid hydrogen buffer tank via pipes. The liquid hydrogen buffer tank is connected to a medium-pressure cylinder group in a gaseous hydrogen storage tank via a third pipe and a first liquid hydrogen vaporization mechanism. This technology can increase hydrogen storage density, improve hydrogen storage and transportation efficiency, and enhance hydrogen refueling capacity. It also follows the same technical route of pressurizing liquid hydrogen with a liquid hydrogen booster pump before vaporizing it. However, it does not take into account the requirements of the liquid hydrogen booster pump for the inlet conditions during actual use. When the pressure inside the liquid hydrogen storage tank is low, resulting in a low inlet pressure for the liquid hydrogen booster pump, the booster pump will have low pressurization efficiency or may not even reach the rated pressure value, thus failing to complete the filling and refueling of high-pressure gaseous hydrogen. Summary of the Invention

[0004] This invention aims to overcome the problem that existing liquid hydrogen booster pumps have high requirements for inlet conditions. When the inlet pressure is low, the booster pump's pressurization efficiency is low or even unable to reach the rated pressure, thus failing to complete the filling and refueling of high-pressure gaseous hydrogen. The invention provides a high-pressure gaseous hydrogen filling system and method based on liquid hydrogen boosting. By connecting a gaseous hydrogen outlet bypass from the liquid hydrogen vaporizer to the liquid hydrogen storage tank, the pressure of the liquid hydrogen stored in the storage tank is increased, thereby increasing the inlet pressure of the liquid hydrogen booster pump, increasing the booster pump's pressurization efficiency, and improving the efficiency of high-pressure gaseous hydrogen filling.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-pressure gaseous hydrogen filling system based on liquid hydrogen pressurization includes a liquid hydrogen storage tank, which is connected to the inlet of a liquid hydrogen vaporizer via a liquid hydrogen booster pump; the first outlet of the liquid hydrogen vaporizer is connected to the liquid hydrogen storage tank via a gaseous hydrogen outlet bypass, and a gaseous hydrogen pressure reducing valve is provided on the gaseous hydrogen outlet bypass; the second outlet of the liquid hydrogen vaporizer is connected to a gaseous hydrogen container.

[0007] In this invention, the liquid hydrogen storage tank, liquid hydrogen booster pump, liquid hydrogen vaporizer, and gaseous hydrogen container are connected in sequence, which is a common connection method in existing high-pressure gaseous hydrogen filling processes. Based on this, a gaseous hydrogen outlet bypass is connected from the liquid hydrogen vaporizer to the liquid hydrogen storage tank. A gaseous hydrogen pressure reducing valve is installed on the gaseous hydrogen outlet bypass so that part of the hydrogen that is completely vaporized at the liquid hydrogen vaporizer is transported back to the liquid hydrogen storage tank through the gaseous hydrogen outlet bypass. This increases and maintains the pressure in the liquid hydrogen storage tank, thereby maintaining the inlet pressure of the liquid hydrogen booster pump, ensuring its normal operation, increasing the booster efficiency, and thus increasing the pressure and flow rate delivered from the liquid hydrogen vaporizer to the gaseous hydrogen container to improve the gaseous hydrogen filling efficiency.

[0008] Preferably, a first gaseous hydrogen control valve is provided between the first outlet of the liquid hydrogen vaporizer and the gaseous hydrogen pressure reducing valve, and a second gaseous hydrogen control valve is provided between the second outlet of the liquid hydrogen vaporizer and the gaseous hydrogen container.

[0009] In this invention, the hydrogen flowing from the liquid hydrogen vaporizer into the gaseous hydrogen outlet bypass first passes through the first gaseous hydrogen control valve to control its flow rate, and then passes through the gaseous hydrogen pressure reducing valve to regulate the hydrogen pressure input to the liquid hydrogen storage tank. The first gaseous hydrogen control valve can also play a certain protective role for the gaseous hydrogen pressure reducing valve. The second gaseous hydrogen control valve is used to control the flow rate from the liquid hydrogen vaporizer to the gaseous hydrogen container.

[0010] Preferably, the first outlet of the liquid hydrogen vaporizer is located at the position within the liquid hydrogen vaporizer closest to the inlet where the liquid hydrogen is completely vaporized.

[0011] In this invention, the purpose of returning the hydrogen gas flowing out from the first outlet of the liquid hydrogen vaporizer to the liquid hydrogen storage tank is to increase and maintain the pressure inside the liquid hydrogen storage tank. The first outlet is located at the position in the liquid hydrogen vaporizer closest to the inlet where the liquid hydrogen is completely vaporized. This allows the low-temperature, high-pressure gaseous hydrogen that has been completely vaporized but whose temperature is still close to that of liquid hydrogen to be led out to the gaseous hydrogen outlet bypass and transported back to the liquid hydrogen storage tank, thereby increasing the pressure while maintaining the temperature inside the liquid hydrogen storage tank at a basically constant level.

[0012] Preferably, the liquid hydrogen storage tank is equipped with a liquid hydrogen storage tank gaseous hydrogen pressure sensor and a safety valve; the gaseous hydrogen container is equipped with a gaseous hydrogen container pressure sensor; and the second outlet of the liquid hydrogen vaporizer is equipped with an outlet gaseous hydrogen pressure sensor.

[0013] In this invention, a liquid hydrogen storage tank gas hydrogen pressure sensor is used to detect the pressure inside the liquid hydrogen storage tank, a safety valve can prevent the pressure inside the liquid hydrogen storage tank from exceeding the safety value, a gas hydrogen container pressure sensor is used to detect the pressure inside the gas hydrogen container, and an outlet gas hydrogen pressure sensor is used to detect the hydrogen pressure at the second outlet of the liquid hydrogen vaporizer.

[0014] Preferably, the gaseous hydrogen outlet bypass uses an insulated pipeline; the outlet pressure of the gaseous hydrogen pressure reducing valve is lower than the pressure safety value of the liquid hydrogen storage tank.

[0015] In this invention, the hydrogen outlet bypass uses an insulated pipeline to prevent the hydrogen in the bypass from exchanging heat with the outside environment and heating up before being transferred back to the liquid hydrogen storage tank, thus ensuring the temperature stability inside the liquid hydrogen storage tank. The low-temperature, high-pressure hydrogen flowing out of the liquid hydrogen vaporizer is depressurized by the hydrogen pressure reducing valve and then input into the liquid hydrogen storage tank. In order to ensure the safety of the liquid hydrogen storage tank, the outlet pressure of the hydrogen pressure reducing valve needs to be lower than the pressure safety value of the liquid hydrogen storage tank, thereby preventing the pressure inside the liquid hydrogen storage tank from exceeding the standard.

[0016] A high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization includes:

[0017] Step 1: After being pressurized by the liquid hydrogen booster pump and vaporized by the liquid hydrogen vaporizer, the hydrogen gas is returned to the liquid hydrogen storage tank through the gaseous hydrogen outlet bypass, increasing the pressure inside the liquid hydrogen storage tank.

[0018] Step 2: When the pressure in the liquid hydrogen storage tank is increased to the normal operating inlet pressure of the liquid hydrogen booster pump, open the second gaseous hydrogen control valve to the preset initial opening degree, and hydrogen enters the gaseous hydrogen container.

[0019] Step 3: When the outlet pressure of the second outlet of the liquid hydrogen vaporizer reaches the rated outlet pressure of the liquid hydrogen booster pump, increase the opening of the second gas hydrogen control valve and increase the power of the liquid hydrogen booster pump to the rated power.

[0020] Step 4: When the pressure inside the gaseous hydrogen container reaches the target storage pressure, shut down the high-pressure gaseous hydrogen filling system.

[0021] The core logic of the high-pressure gaseous hydrogen filling method in this invention is to increase the storage pressure in the liquid hydrogen storage tank to raise the inlet pressure of the liquid hydrogen booster pump, thereby increasing the boosting efficiency of the liquid hydrogen booster pump. Through the coordinated control of the first and second gaseous hydrogen control valves, the storage pressure in the liquid hydrogen storage tank is preferentially increased through the gaseous hydrogen outlet bypass and kept below the pressure safety value to ensure that the inlet pressure of the liquid hydrogen booster pump meets the requirements for normal operation, thereby improving the boosting efficiency of the liquid hydrogen booster pump. Under the premise that the liquid hydrogen booster pump is at a high boosting efficiency, the power of the liquid hydrogen booster pump is increased to increase the flow rate from the liquid hydrogen vaporizer to the gaseous hydrogen container. The high-pressure gaseous hydrogen filling system of this invention is equipped with corresponding control modules that connect to the control valves, liquid hydrogen booster pump, sensors, and safety valves in the system to collect data and control the filling of high-pressure gaseous hydrogen.

[0022] Preferably, in step one, the second gaseous hydrogen control valve is kept closed while the first gaseous hydrogen control valve is fully opened, and the liquid hydrogen booster pump is started to operate at a preset power. The hydrogen gas, after being vaporized by the liquid hydrogen vaporizer, is depressurized by the gaseous hydrogen pressure reducing valve and then enters the liquid hydrogen storage tank.

[0023] The purpose of keeping the second gaseous hydrogen control valve closed in this invention is to ensure that the low-temperature, high-pressure gaseous hydrogen after being vaporized by the liquid hydrogen vaporizer in the initial stage is mainly input into the liquid hydrogen storage tank through the gaseous hydrogen outlet bypass to increase the pressure. In this stage, since the inlet liquid pressure is low and the pressurization efficiency is not high, the liquid hydrogen booster pump only operates at a small power (preset power). The preset power can be set in advance according to the actual situation and needs.

[0024] Preferably, in step two, while reducing the opening of the first gaseous hydrogen control valve, the second gaseous hydrogen control valve is gradually opened to a preset initial opening to maintain a constant pressure inside the liquid hydrogen storage tank.

[0025] Step two in this invention involves collecting pressure data from the liquid hydrogen storage tank and performing feedback control. By coordinating the control between the first and second gaseous hydrogen control valves, the pressure in the liquid hydrogen storage tank is kept basically constant, thereby maintaining the inlet pressure of the liquid hydrogen booster pump at its normal operating inlet pressure requirements.

[0026] The present invention has the following beneficial effects: by connecting the gaseous hydrogen outlet bypass from the liquid hydrogen vaporizer to the liquid hydrogen storage tank, the pressure of the liquid hydrogen stored in the liquid hydrogen storage tank is increased to increase the inlet pressure of the liquid hydrogen booster pump, ensuring that the inlet pressure of the liquid hydrogen booster pump meets its normal operating requirements, thereby increasing the boosting efficiency of the liquid hydrogen booster pump and improving the efficiency of high-pressure gaseous hydrogen filling. Attached Figure Description

[0027] Figure 1 This is a structural diagram of the high-pressure gaseous hydrogen filling system in this invention;

[0028] Figure 2 This is a flowchart of the high-pressure gaseous hydrogen filling method in this invention;

[0029] In the diagram: 1. Liquid hydrogen storage tank; 2. Liquid hydrogen booster pump; 3. Liquid hydrogen vaporizer; 4. Gas hydrogen container; 5. Gas hydrogen outlet bypass; 6. Gas hydrogen pressure reducing valve; 7. First gas hydrogen control valve; 8. Second gas hydrogen control valve; 9. Liquid hydrogen storage tank gas hydrogen pressure sensor; 10. Gas hydrogen container pressure sensor; 11. Outlet gas hydrogen pressure sensor; 12. Safety valve. Detailed Implementation

[0030] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1 As shown, a high-pressure gaseous hydrogen filling system based on liquid hydrogen pressurization includes a liquid hydrogen storage tank 1, a liquid hydrogen booster pump 2, a liquid hydrogen vaporizer 3, a gaseous hydrogen container 4, a gaseous hydrogen outlet bypass 5, and a gaseous hydrogen pressure reducing valve 6. The liquid hydrogen storage tank 1 is connected to the inlet of the liquid hydrogen vaporizer 3 via the liquid hydrogen booster pump 2; the first outlet of the liquid hydrogen vaporizer 3 is connected to the liquid hydrogen storage tank 1 via the gaseous hydrogen outlet bypass 5 (in which low-temperature, high-pressure gaseous hydrogen flows), and the gaseous hydrogen outlet bypass 5 is equipped with a gaseous hydrogen pressure reducing valve 6 (to reduce the pressure of the low-temperature, high-pressure gaseous hydrogen); the second outlet of the liquid hydrogen vaporizer 3 is connected to the gaseous hydrogen container 4.

[0032] The inlet of the liquid hydrogen booster pump 2 is connected to the liquid phase space at the bottom of the liquid hydrogen storage tank 1, and the output end of the gas hydrogen outlet bypass 5 is connected to the gas phase space at the top of the liquid hydrogen storage tank 1.

[0033] A first gaseous hydrogen control valve 7 (controlling the flow rate of low-temperature high-pressure gaseous hydrogen) is installed between the first outlet of the liquid hydrogen vaporizer 3 and the gaseous hydrogen pressure reducing valve 6. A second gaseous hydrogen control valve 8 (controlling the flow rate of room-temperature high-pressure gaseous hydrogen flowing into the gaseous hydrogen container 4) is installed between the second outlet of the liquid hydrogen vaporizer 3 and the gaseous hydrogen container 4.

[0034] The first outlet of the liquid hydrogen vaporizer 3 is located at the point within the liquid hydrogen vaporizer 3 closest to the inlet where the liquid hydrogen is completely vaporized, that is, at the point where the liquid hydrogen in the liquid hydrogen vaporizer 3 is just completely vaporized under the rated power of the liquid hydrogen booster pump 2. The gaseous hydrogen outlet bypass 5 is located on the pipeline of the liquid hydrogen vaporizer 3 near the inlet. Through the gaseous hydrogen outlet bypass 5, the portion of low-temperature, high-pressure gaseous hydrogen that has just been completely vaporized but is still close to the liquid hydrogen temperature is led out and pressured to a pressure slightly lower than the safe pressure value of the liquid hydrogen storage tank 1 by the gaseous hydrogen pressure reducing valve 6 before entering the liquid hydrogen storage tank 1 to increase the pressure inside the liquid hydrogen storage tank.

[0035] Liquid hydrogen storage tank 1 is equipped with a liquid hydrogen storage tank gaseous hydrogen pressure sensor 9 (to monitor the storage pressure inside the liquid hydrogen storage tank) and a safety valve 12 (to prevent the storage pressure inside the liquid hydrogen storage tank from exceeding the safe value); gaseous hydrogen container 4 is equipped with a gaseous hydrogen container pressure sensor 10 (to monitor the gas pressure inside the gaseous hydrogen container); an outlet gaseous hydrogen pressure sensor 11 is installed between the second outlet of liquid hydrogen vaporizer 3 and the second gaseous hydrogen control valve 8 to monitor the pressure of room temperature high-pressure gaseous hydrogen after being pressurized by liquid hydrogen booster pump 2 and vaporized and heated by liquid hydrogen vaporizer 3.

[0036] The entire gaseous hydrogen outlet bypass 5 uses cryogenic insulated pipelines; the outlet pressure of the gaseous hydrogen pressure reducing valve 6 is lower than the pressure safety value of the liquid hydrogen storage tank 1.

[0037] In this invention, the liquid hydrogen storage tank, liquid hydrogen booster pump, liquid hydrogen vaporizer, and gaseous hydrogen container are connected in sequence, which is a common connection method in existing high-pressure gaseous hydrogen filling processes. Based on this, a gaseous hydrogen outlet bypass is connected from the liquid hydrogen vaporizer to the liquid hydrogen storage tank. A gaseous hydrogen pressure reducing valve is installed on the gaseous hydrogen outlet bypass so that part of the hydrogen that is completely vaporized at the liquid hydrogen vaporizer is transported back to the liquid hydrogen storage tank through the gaseous hydrogen outlet bypass. This increases and maintains the pressure in the liquid hydrogen storage tank, thereby maintaining the inlet pressure of the liquid hydrogen booster pump, ensuring its normal operation, increasing the booster efficiency, and thus increasing the pressure and flow rate delivered from the liquid hydrogen vaporizer to the gaseous hydrogen container to improve the gaseous hydrogen filling efficiency.

[0038] In this invention, the hydrogen flowing from the liquid hydrogen vaporizer into the gaseous hydrogen outlet bypass first passes through a first gaseous hydrogen control valve to control its flow rate, and then through a gaseous hydrogen pressure reducing valve to regulate the hydrogen pressure input to the liquid hydrogen storage tank. The first gaseous hydrogen control valve can also provide some protection for the gaseous hydrogen pressure reducing valve. The second gaseous hydrogen control valve is used to control the flow rate from the liquid hydrogen vaporizer to the gaseous hydrogen container. Through the coordinated control of the first and second gaseous hydrogen control valves, the pipeline control between the liquid hydrogen booster pump and the liquid hydrogen vaporizer can be achieved, eliminating the need for additional control valves between the liquid hydrogen booster pump and the liquid hydrogen vaporizer.

[0039] In this invention, the purpose of returning the hydrogen gas flowing out from the first outlet of the liquid hydrogen vaporizer to the liquid hydrogen storage tank is to increase and maintain the pressure inside the liquid hydrogen storage tank. The first outlet is located at the position in the liquid hydrogen vaporizer closest to the inlet where the liquid hydrogen is completely vaporized. This allows the low-temperature, high-pressure gaseous hydrogen that has been completely vaporized but whose temperature is still close to that of liquid hydrogen to be led out to the gaseous hydrogen outlet bypass and transported back to the liquid hydrogen storage tank, thereby increasing the pressure while maintaining the temperature inside the liquid hydrogen storage tank at a basically constant level.

[0040] In this invention, a liquid hydrogen storage tank gaseous hydrogen pressure sensor is used to detect the pressure inside the liquid hydrogen storage tank. A safety valve can prevent the pressure inside the liquid hydrogen storage tank from exceeding the safe value. A gaseous hydrogen container pressure sensor is used to detect the pressure inside the gaseous hydrogen container. An outlet gaseous hydrogen pressure sensor is used to detect the hydrogen pressure at the second outlet of the liquid hydrogen vaporizer. By setting the outlet gaseous hydrogen pressure sensor, it is not necessary to set an additional cryogenic pressure sensor between the liquid hydrogen booster pump and the liquid hydrogen vaporizer.

[0041] In this invention, the hydrogen outlet bypass uses an insulated pipeline to prevent the hydrogen in the bypass from exchanging heat with the outside environment and heating up before being transferred back to the liquid hydrogen storage tank, thus ensuring the temperature stability inside the liquid hydrogen storage tank. The low-temperature, high-pressure hydrogen flowing out of the liquid hydrogen vaporizer is depressurized by the hydrogen pressure reducing valve and then input into the liquid hydrogen storage tank. In order to ensure the safety of the liquid hydrogen storage tank, the outlet pressure of the hydrogen pressure reducing valve needs to be lower than the pressure safety value of the liquid hydrogen storage tank, thereby preventing the pressure inside the liquid hydrogen storage tank from exceeding the standard.

[0042] like Figure 2 As shown, a high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization includes:

[0043] Step 1: After being pressurized by the liquid hydrogen booster pump and vaporized by the liquid hydrogen vaporizer, the hydrogen gas is returned to the liquid hydrogen storage tank through the gaseous hydrogen outlet bypass, increasing the pressure inside the liquid hydrogen storage tank.

[0044] Close the second hydrogen control valve and open the first hydrogen control valve to its maximum opening. Start the liquid hydrogen booster pump and operate it at the preset power. Low-temperature, high-pressure hydrogen is depressurized through the hydrogen pressure reducing valve of the hydrogen outlet bypass and then fed into the liquid hydrogen storage tank, gradually increasing the storage pressure in the liquid hydrogen storage tank.

[0045] Step 2: When the pressure in the liquid hydrogen storage tank is increased to the normal operating inlet pressure of the liquid hydrogen booster pump, open the second gaseous hydrogen control valve to the preset initial opening degree, and hydrogen enters the gaseous hydrogen container.

[0046] When the pressure value of the gas pressure sensor in the liquid hydrogen storage tank reaches the inlet pressure required for the liquid hydrogen booster pump to operate normally and achieve high boosting efficiency, the opening of the first gas hydrogen control valve is reduced and the second gas hydrogen control valve is opened to the preset initial opening to maintain the value of the gas pressure sensor in the liquid hydrogen storage tank unchanged.

[0047] Step 3: When the outlet pressure of the second outlet of the liquid hydrogen vaporizer (the value of the outlet gas hydrogen pressure sensor) reaches the rated outlet pressure of the liquid hydrogen booster pump, increase the opening of the second gas hydrogen control valve and increase the operating power of the liquid hydrogen booster pump to the rated power.

[0048] Step 4: When the pressure inside the gaseous hydrogen container (the value of the gaseous hydrogen container pressure sensor) reaches the target storage pressure, shut down the high-pressure gaseous hydrogen filling system; shut down the liquid hydrogen booster pump, the first gaseous hydrogen control valve, and the second gaseous hydrogen control valve until the next high-pressure gaseous hydrogen filling process.

[0049] In the high-pressure hydrogen filling process of this invention, the liquid hydrogen storage tank does not need to be equipped with a self-pressurization system. For liquid hydrogen storage tanks already equipped with a self-pressurization system, the gaseous hydrogen outlet bypass and the gaseous hydrogen pressure reducing valve and the first gaseous hydrogen control valve on its line can be eliminated. The self-pressurization system configured in the liquid hydrogen storage tank increases the storage pressure inside the liquid hydrogen storage tank and maintains it below the pressure safety value, thereby ensuring that the inlet pressure of the liquid hydrogen booster pump is at a high level, thus improving the booster efficiency of the liquid hydrogen booster pump. Under the premise that the liquid hydrogen booster pump is at a high booster efficiency, the flow rate from the liquid hydrogen vaporizer to the high-pressure hydrogen container is increased.

[0050] The core logic of the high-pressure gaseous hydrogen filling method in this invention is to increase the storage pressure in the liquid hydrogen storage tank to raise the inlet pressure of the liquid hydrogen booster pump, thereby increasing the boosting efficiency of the liquid hydrogen booster pump. Through the coordinated control of the first and second gaseous hydrogen control valves, the storage pressure in the liquid hydrogen storage tank is preferentially increased through the gaseous hydrogen outlet bypass and kept below the pressure safety value to ensure that the inlet pressure of the liquid hydrogen booster pump meets the requirements for normal operation, thereby improving the boosting efficiency of the liquid hydrogen booster pump. Under the premise that the liquid hydrogen booster pump is at a high boosting efficiency, the power of the liquid hydrogen booster pump is increased to increase the flow rate from the liquid hydrogen vaporizer to the gaseous hydrogen container. The high-pressure gaseous hydrogen filling system of this invention is equipped with corresponding control modules that connect to the control valves, liquid hydrogen booster pump, sensors, and safety valves in the system to collect data and control the filling of high-pressure gaseous hydrogen.

[0051] The purpose of keeping the second gaseous hydrogen control valve closed in this invention is to ensure that the low-temperature, high-pressure gaseous hydrogen after being vaporized by the liquid hydrogen vaporizer in the initial stage is mainly input into the liquid hydrogen storage tank through the gaseous hydrogen outlet bypass to increase the pressure. In this stage, since the inlet liquid pressure is low and the pressurization efficiency is not high, the liquid hydrogen booster pump only operates at a small power (preset power). The preset power can be set in advance according to the actual situation and needs.

[0052] Step two in this invention involves collecting pressure data from the liquid hydrogen storage tank and performing feedback control. By coordinating the control between the first and second gaseous hydrogen control valves, the pressure in the liquid hydrogen storage tank is kept basically constant, thereby maintaining the inlet pressure of the liquid hydrogen booster pump at its normal operating inlet pressure requirements.

[0053] In this embodiment of the invention, the safe storage pressure of the liquid hydrogen storage tank is set to 0.8 MPa, the initial pressure of the liquid hydrogen in the tank is 0.2 MPa, and the temperature is approximately 23 K; the rated outlet pressure of the liquid hydrogen booster pump is 90 MPa, the rated power is Pn, and the inlet pressure required for high boosting efficiency during normal operation is 0.6 MPa; the outlet pressure of the gaseous hydrogen pressure reducing valve is 0.7 MPa; after the high-pressure liquid hydrogen input from the liquid hydrogen booster pump to the liquid hydrogen vaporizer undergoes a vaporization and heating process, the hydrogen at the second outlet of the liquid hydrogen vaporizer reaches room temperature; the target storage pressure for the gaseous hydrogen container is 85 MPa. The connection point between the gaseous hydrogen outlet bypass and the liquid hydrogen vaporizer is selected at a position where the liquid hydrogen in the liquid hydrogen vaporizer is just completely vaporized under the rated operating conditions of the liquid hydrogen booster pump. The entire gaseous hydrogen outlet bypass uses cryogenic insulated piping. Under these parameter settings, a complete high-pressure gaseous hydrogen filling process is as follows:

[0054] Step 1: Keep the second hydrogen control valve closed, open the first hydrogen control valve (maximum opening), and start the liquid hydrogen booster pump at 0.5 times its rated power for low-power operation. At this time, the inlet pressure of the liquid hydrogen booster pump is low, the boosting efficiency is not high, and it may not even be able to boost the liquid hydrogen to the rated pressure. The liquid hydrogen, after being boosted by the liquid hydrogen booster pump, enters the liquid hydrogen vaporizer, where it vaporizes and heats up through heat exchange with the environment. When it reaches the connection point of the hydrogen outlet bypass (i.e., the first outlet of the liquid hydrogen vaporization), the liquid hydrogen is completely vaporized but still at a low temperature (about 30K). This low-temperature, high-pressure hydrogen gas is depressurized to 0.7MPa through the hydrogen outlet bypass and the hydrogen pressure reducing valve before entering the liquid hydrogen storage tank, gradually increasing the storage pressure in the liquid hydrogen storage tank.

[0055] Step 2: When the pressure reading of the gas pressure sensor in the liquid hydrogen storage tank increases to 0.6 MPa (the inlet pressure required for high boosting efficiency when the liquid hydrogen booster pump is operating normally), the opening of the first gas hydrogen control valve is gradually reduced while the second gas hydrogen control valve is opened at a preset initial opening. These two valves work together to maintain a constant reading on the gas pressure sensor in the liquid hydrogen storage tank, thus keeping the pressure inside the tank constant. At this point, the inlet pressure of the liquid hydrogen booster pump is maintained at 0.6 MPa, maintaining high boosting efficiency. Because the second gas hydrogen control valve is open, some room-temperature, high-pressure gas hydrogen enters the gas hydrogen container. However, due to the relatively small opening of the second gas hydrogen control valve, the total amount of hydrogen entering the liquid hydrogen vaporizer per unit time is still greater than the total amount of hydrogen leaving the vaporizer, causing the pressure at the outlet of the liquid hydrogen vaporizer to gradually increase.

[0056] Step 3: When the pressure value of the outlet hydrogen pressure sensor reaches the rated outlet pressure of the liquid hydrogen booster pump, i.e., 90MPa, gradually increase the opening of the second hydrogen control valve, and at the same time gradually increase the operating power of the liquid hydrogen booster pump to the rated power, thereby increasing the flow rate of room temperature high-pressure hydrogen input to the hydrogen container and improving the filling efficiency.

[0057] Step 4: When the pressure sensor in the gaseous hydrogen container detects that the pressure inside the gaseous hydrogen container has reached the target storage pressure of 85 MPa, shut down the liquid hydrogen booster pump, the second gaseous hydrogen control valve, and the first gaseous hydrogen control valve to complete the filling of the gaseous hydrogen container.

[0058] The next high-pressure hydrogen filling process can simply repeat the above steps.

[0059] The above embodiments are further elaborations and descriptions of the present invention to facilitate understanding, and are not intended to limit the present invention in any way. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization, characterized in that, The system includes a high-pressure gaseous hydrogen filling system equipped with a liquid hydrogen storage tank, the liquid hydrogen storage tank being connected to the inlet of a liquid hydrogen vaporizer via a liquid hydrogen booster pump; the first outlet of the liquid hydrogen vaporizer being connected to the liquid hydrogen storage tank via a gaseous hydrogen outlet bypass equipped with a first gaseous hydrogen control valve and a gaseous hydrogen pressure reducing valve in sequence; the second outlet of the liquid hydrogen vaporizer being connected to a gaseous hydrogen container via a second gaseous hydrogen control valve; the method includes: Step 1: After being pressurized by the liquid hydrogen booster pump and vaporized by the liquid hydrogen vaporizer, the hydrogen gas is returned to the liquid hydrogen storage tank through the gaseous hydrogen outlet bypass, increasing the pressure inside the liquid hydrogen storage tank. Step 2: When the pressure in the liquid hydrogen storage tank is increased to the normal operating inlet pressure of the liquid hydrogen booster pump, reduce the opening of the first gaseous hydrogen control valve and simultaneously open the second gaseous hydrogen control valve to the preset initial opening, keeping the pressure in the liquid hydrogen storage tank constant, and hydrogen enters the gaseous hydrogen container. Step 3: When the outlet pressure of the second outlet of the liquid hydrogen vaporizer reaches the rated outlet pressure of the liquid hydrogen booster pump, increase the opening of the second gas hydrogen control valve and increase the power of the liquid hydrogen booster pump to the rated power. Step 4: When the pressure inside the gaseous hydrogen container reaches the target storage pressure, shut down the high-pressure gaseous hydrogen filling system.

2. The high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization according to claim 1, characterized in that, In step one, the second gaseous hydrogen control valve is kept closed and the first gaseous hydrogen control valve is fully opened. The liquid hydrogen booster pump is started to operate at the preset power. The hydrogen gas, after being vaporized by the liquid hydrogen vaporizer, is depressurized by the gaseous hydrogen pressure reducing valve and then enters the liquid hydrogen storage tank.

3. A high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization according to claim 1 or 2, characterized in that, In step two, the pressure inside the liquid hydrogen storage tank is acquired by a liquid hydrogen storage tank gas hydrogen pressure sensor installed on the liquid hydrogen storage tank.

4. The high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization according to claim 1, characterized in that, The outlet pressure of the gaseous hydrogen pressure reducing valve is lower than the safe pressure value of the liquid hydrogen storage tank.

5. A high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization according to claim 1 or 4, characterized in that, The first outlet of the liquid hydrogen vaporizer (3) is located at the position where the liquid hydrogen is completely vaporized, closest to the inlet inside the liquid hydrogen vaporizer (3).

6. The high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization according to claim 5, characterized in that, The liquid hydrogen storage tank (1) is equipped with a liquid hydrogen storage tank gas hydrogen pressure sensor (9) and a safety valve (12); the gas hydrogen container (4) is equipped with a gas hydrogen container pressure sensor (10); and the second outlet of the liquid hydrogen vaporizer (3) is equipped with an outlet gas hydrogen pressure sensor (11).

7. A high-pressure gaseous hydrogen filling method based on liquid hydrogen pressurization according to claim 1, 4, or 6, characterized in that, The hydrogen outlet bypass (5) uses an insulated pipeline.

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