Liquid hydrogen station with cold storage function and hydrogenation method

Abstract

The invention discloses a liquid hydrogen filling station and a hydrogenation control method. The technical problems that in the prior art, equipment investment cost and energy consumption are increased due to precooling treatment of hydrogen, a pump body cannot be accurately controlled and power consumption is high due to the single function of an alternating current contactor of a hydrogen refueling station, and a fire and gas system cannot independently control equipment shutdown and valve cut-off are solved. The cold energy released by liquid hydrogen vaporization is absorbed by the refrigerant in the liquid hydrogen pressurization vaporization process, and the cold energy is released to cool the filling pipeline when the hydrogen filling requirement exists, so that hydrogen cooling is realized, and the requirement that the temperature does not exceed 85 DEG C after the vehicle-mounted hydrogen storage bottle is filled is met. Meanwhile, full-process automatic control over automatic gasification, automatic storage, automatic heat exchange, automatic filling and the like of the liquid hydrogen station is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy, and in particular to a liquid hydrogen filling station and a hydrogenation control method. Background Art

[0002] As a fuel, hydrogen only produces water as a combustion product, which will not aggravate the greenhouse effect and is an ideal clean energy. Therefore, hydrogen has received extensive attention in the field of new energy. As an important link in the hydrogen energy industry chain, liquid hydrogen filling stations are key infrastructure connecting hydrogen energy production and application. Liquid hydrogen filling stations provide filling services for hydrogen fuel cell vehicles by converting liquid hydrogen into gaseous hydrogen, and are important supporting equipment for the promotion and application of fuel cell vehicles. With the continuous advancement of technology and policy support, the role of liquid hydrogen filling stations in the hydrogen energy industry has become increasingly prominent, becoming a core node for promoting the widespread application of hydrogen energy.

[0003] Existing liquid hydrogen stations usually involve complex storage, transportation and filling technologies. During the filling process, since hydrogen is compressed and releases heat, it is necessary to pre-cool the hydrogen to lower its temperature. This process requires the use of a chiller, which not only increases the equipment investment cost and energy consumption, but also wastes the cold energy released when liquid hydrogen is converted into hydrogen. In addition, conventional hydrogen refueling stations control the start and stop of the pump body through an AC contactor, but the AC contactor only has an on-off function and cannot achieve speed regulation and precise control, resulting in the pump body can only run at full speed, resulting in high power consumption. At the same time, the fire and gas system of a conventional hydrogen refueling station is a separate alarm device, which cannot independently control the equipment shutdown and valve cut-off, posing a safety hazard.

[0004] The information disclosed in this background technology section is only used to deepen the understanding of the background technology of the present disclosure, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0005] In view of at least one of the above technical problems, the present disclosure provides a liquid hydrogen filling station and a hydrogenation control method. During the pressurization and vaporization process of liquid hydrogen, a refrigerant is used to absorb the cold energy released during the vaporization of liquid hydrogen. When there is a demand for hydrogen filling, the refrigerant releases the cold energy to cool the filling pipeline, thereby achieving the purpose of cooling the hydrogen.

[0006] According to one aspect of the present disclosure, there is provided a liquid hydrogen filling station, comprising a liquid hydrogen storage tank, a filling system and a control unit, wherein the filling system comprises a high-pressure vaporizer installed in an output pipeline of the liquid hydrogen storage tank, a gas hydrogen storage bottle connected to the output pipeline of the high-pressure vaporizer, and a hydrogenation system, characterized in that: it also comprises a cold energy recovery system, the cold energy recovery system comprises a spray tower installed between the liquid hydrogen storage tank and the high-pressure vaporizer, a hydrogen heat exchanger installed on an input pipeline of the hydrogenation system, a refrigerant liquid phase storage tank is installed on the refrigerant liquid phase pipeline between the spray tower and the hydrogen heat exchanger, a refrigerant gas phase storage tank is installed on the refrigerant gas phase pipeline between the spray tower and the hydrogen heat exchanger, and the top of the refrigerant liquid phase storage tank is connected to the input end of the refrigerant gas phase storage tank.

[0007] Furthermore, the spray tower includes a tower body, a nozzle installed on the top of the tower body and connected to the boost output pipeline of the liquid hydrogen storage tank, and a coil heat exchanger installed in the spray tower.

[0008] Furthermore, the refrigerant liquid phase storage tank includes a tank body, a wire mesh filter installed on the upper part of the tank body, and a pressure transmitter installed on the top of the tank body; the refrigerant liquid phase storage tank is a vacuum multi-layer insulation structure to prevent the loss of refrigerant cold energy.

[0009] Furthermore, the liquefaction temperature of the refrigerant liquid is controlled to be -50°C to -30°C.

[0010] Furthermore, the control unit includes a PLC controller and several frequency converters electrically connected to the PLC controller; the control unit is electrically connected to the hydrogen detector, flame detector, temperature transmitter, and pressure transmitter in the signal detection device, is electrically connected to the emergency stop button in the action input device, and is electrically connected to the sound and light alarm, shut-off valve, regulating valve, and pump body in the action execution device.

[0011] According to another aspect of the present disclosure, a hydrogenation method is provided, including a safety control process and a hydrogenation process, which is implemented based on the liquid hydrogen filling station and also includes the following automatic cold storage hydrogen storage process: (1) Liquid hydrogen pressurization: When the control unit detects that the pressure of the gas hydrogen storage bottle is less than the starting filling set value, the interlock opens the relevant valves of the hydrogen storage and cold storage pipelines and starts the liquid hydrogen booster pump to pressurize the liquid hydrogen in the liquid hydrogen storage bottle and input it into the pipeline; (2) Cold energy exchange: Liquid hydrogen passes through the spray tower, is atomized into small droplets by the nozzle at the top of the tower, and is heat exchanged with the gas phase refrigerant through the coil heat exchanger; (3) Refrigerant liquefaction: The gas phase refrigerant absorbs the cold energy of liquid hydrogen in the coil heat exchanger and then liquefies and flows into the refrigerant liquid phase storage tank; (4) Temperature control of the cold storage device: The control unit dynamically adjusts the opening of the regulating valve according to the temperature of the cold storage liquid phase tank. When the temperature exceeds the maximum cold storage temperature, the regulating valve is interlocked to open, and when the temperature is lower than the minimum cold storage temperature, the regulating valve is closed to maintain the temperature of the liquid cold storage agent within a constant range. (5) Pressure regulation of cold storage device: The pressure of the cold storage liquid tank will increase due to the gaseous components entrained when the liquid cold storage enters. When the control unit detects that the pressure exceeds the set value, the relevant valves of the pressure reducing pipeline are interlocked to open and the gas booster pump is started to pressurize the gaseous cold storage into the cold storage gas tank; when the pressure is lower than the threshold, the relevant actuator is automatically closed; (6) Liquid hydrogen vaporization: In the spray tower, the liquid hydrogen releases cold energy and partially vaporizes, and the unvaporized portion continues to vaporize after entering the high-pressure vaporizer; (7) Hydrogen storage and termination: Liquid hydrogen is completely vaporized into hydrogen gas through the high-pressure vaporizer and transported to the hydrogen storage bottle through a pipeline. When the control unit detects that the hydrogen storage bottle is full, the valves related to the hydrogen storage and cold storage pipelines and the liquid hydrogen booster pump are closed in a chain manner.

[0012] Furthermore, the safety control process includes: (1) When an emergency occurs, the staff can press the emergency stop button so that the control unit receives the emergency stop signal from the emergency stop button and interlocks the emergency stop of the entire station equipment; (2) The control unit receives the alarm data of the hydrogen detector in real time, and interlocks and shuts down related equipment according to the alarm data; (3) The control unit receives the alarm signal of the flame detector in real time, and interlocks the entire station for emergency shutdown according to the alarm signal; (4) When the system alarm occurs, the control unit will interlock the sound and light alarm to alarm.

[0013] Furthermore, the hydrogenation process comprises: (1) Precooling: When the control unit receives a start signal from the hydrogenation system, it opens the valves related to the hydrogenation and precooling pipelines and starts the liquid circulation pump, so that the liquid refrigerant enters the shell side of the hydrogen heat exchanger to exchange heat with the hydrogen supplied from the hydrogen storage bottle into the tube side of the hydrogen heat exchanger; (2) Gas-hydrogen temperature control: The liquid phase refrigerant releases cold energy and its temperature rises, and is converted into the gas phase. During the phase change, cold energy is released, and hydrogen absorbs cold energy, and its temperature decreases. The control unit detects the hydrogen temperature at the hydrogen outlet of the hydrogen heat exchanger in real time, and automatically adjusts the operating speed of the liquid circulation pump to keep the hydrogen temperature within the set range. (3) Hydrogenation: The gas phase refrigerant after heat exchange enters the refrigerant gas phase storage, and the pre-cooled hydrogen enters the hydrogen supply system and completes the refueling of the vehicle; (4) Stop supplying hydrogen: When the control unit receives the signal that the hydrogenation system is completed, it interlocks and closes the valves related to the hydrogenation and precooling pipelines and turns off the liquid circulation pump, and the hydrogenation process ends.

[0014] One or more technical solutions provided in the embodiments of the present application have at least any of the following technical effects or advantages: (1) The spray tower effectively solves the problem of insufficient heat exchange between liquid hydrogen and gas-phase refrigerant, thereby improving the heat transfer efficiency.

[0015] (2) The refrigerant is used to absorb the large amount of cold energy released by liquid hydrogen during the vaporization process to cool the hydrogen during the refueling process, which solves the problem of high investment costs for pre-cooling equipment at liquid hydrogen filling stations, thereby reducing investment costs and saving energy.

[0016] (3) The use of a cold storage tank with a vacuum multi-layer insulation structure solves the problem of easy loss of cold energy, thereby saving energy.

[0017] (4) The start and stop and speed of the pump are controlled by a frequency converter, which solves the problem that traditional equipment can only run at full speed, thereby achieving precise control of the pump and reducing electricity consumption.

[0018] (5) By electrically connecting the signal detection device, the action execution device and the control unit, the problem of conventional hydrogen refueling stations only giving an alarm but not interlocking the equipment and valves for emergency shutdown is solved, thereby ensuring the safe operation of the liquid hydrogen station. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a flow chart of a liquid hydrogen filling station in one embodiment of the present application.

[0020] Figure 2 This is a system topology diagram in one embodiment of the present application.

[0021] Figure 3 This is a flow chart of gasification, heat exchange and hydrogen storage in another embodiment of the present application.

[0022] Figure 4 This is a flow chart of hydrogenation and heat exchange in another embodiment of the present application.

[0023] In the above figures, 01 is a liquid hydrogen storage tank, 11 is the first shut-off valve, 12 is a liquid hydrogen booster pump, 02 is a spray tower, 21 is a nozzle, 22 is a coil heat exchanger, 23 is the first temperature transmitter, 24 is the second shut-off valve, 03 is a high-pressure vaporizer, 31 is the third shut-off valve, 32 is the fourth shut-off valve, 33 is the fifth shut-off valve, 34 is the first check valve, 04 is a gas hydrogen storage bottle, 05 is a hydrogenation system, 06 is a gas hydrogen storage bottle, 07 is a gas hydrogen storage bottle, 08 is a gas hydrogenation system, 09 is a gas hydrogen storage bottle, 10 is a gas hydrogenation system, 11 is a gas hydrogen storage bottle, 12 is a gas hydrogenation system, 13 is a gas hydrogen storage bottle, 14 is a gas hydrogen storage bottle, 15 is a gas hydrogenation system, is a refrigerant gas phase storage tank, 61 is a regulating valve, 07 is a refrigerant liquid phase storage tank, 71 is the 6th shut-off valve, 72 is a liquid circulation pump, 08 is a hydrogen heat exchanger, 73 is the 1st check valve, 74 is the 7th shut-off valve, 75 is a gas booster pump, 76 is the 2nd check valve, 77 is a wire mesh filter, 78 is a pressure transmitter, 81 is the 2nd check valve, 82 is the 8th shut-off valve, and 83 is the 2nd temperature transmitter. DETAILED DESCRIPTION

[0024] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "vertical", "horizontal", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The terms "first", "second", etc. involved in the present application are used to distinguish the objects described and do not have any order or technical meaning. The terms "connection" and "connection" involved in the present application, unless otherwise specified, include direct and indirect connections (connections).

[0025] The unit modules (components, structures, mechanisms) or sensors and other devices involved in the following embodiments are conventional commercially available products unless otherwise specified.

[0026] The embodiment of the present application provides a liquid hydrogen filling station and a hydrogenation control method, which solves the problems of high energy consumption, large investment and potential safety hazards of hydrogenation stations in the prior art. The above problems are effectively solved by installing a cold energy recovery and utilization system including a spray tower and a vacuum multi-layer insulation structure refrigerant liquid phase storage tank in the liquid hydrogen filling station and setting a frequency converter in the control unit.

[0027] The technical solution in the embodiment of the present application is to solve the above problems, and the overall idea is as follows: Liquid hydrogen is partially vaporized by the spray tower, and the cold energy released by the vaporization is stored in the refrigerant liquid phase storage tank by the refrigerant. The temperature and pressure of the refrigerant liquid phase storage tank are monitored in real time by the signal detection device and transmitted to the control unit through the electrical signal. The control unit in turn adjusts the temperature and pressure of the refrigerant liquid phase storage tank by controlling the action execution device. After high-pressure vaporization, the liquid hydrogen is completely vaporized and stored in the gas hydrogen storage bottle. During hydrogenation, the hydrogen in the gas hydrogen storage bottle exchanges heat with the liquid phase refrigerant in the heat exchanger, and the real-time hydrogen temperature delivered to the hydrogenation system is transmitted to the control unit through the temperature sensor. The control unit controls the flow rate of the refrigerant by controlling the liquid circulation pump, thereby controlling the temperature of the hydrogen.

[0028] The hydrogen detector and flame detector transmit the alarm data to the PLC controller, and the PLC controller interlocks the sound and light alarm according to the alarm data; when an emergency occurs or the emergency stop button is pressed, the PLC controller receives the emergency stop signal and interlocks the shut-off valve, regulating valve, and inverter for emergency stop.

[0029] In order to better understand the technical solution of the present application, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0030] Example This example discloses a liquid hydrogen filling station, see Figure 1 , specifically including a liquid hydrogen storage tank 01, a hydraulic booster pump 12 connected to the output pipeline of the liquid hydrogen storage bottle, a filling system, a cold energy recovery system and a control unit, the filling system including a high-pressure vaporizer 03 connected to the output pipeline of the liquid hydrogen booster pump 12, a gas hydrogen storage bottle 04 connected to the output pipeline of the high-pressure vaporizer 03 and a hydrogenation system 05, the cold energy recovery system including a spray tower 02 installed between the hydraulic booster pump 12 and the high-pressure vaporizer 03, a hydrogen heat exchanger 08 installed on the input pipeline of the hydrogenation system 05, a refrigerant liquid phase storage tank 07 installed on the output pipeline of the spray tower 02, and at the same time, connected to the hydrogen heat exchanger 08 through a pipeline with a liquid circulation pump 72; a refrigerant gas phase storage tank 06 is installed on the input pipeline of the spray tower 08, and the refrigerant liquid phase storage tank 07 and the hydrogen heat exchanger 08 are connected to the refrigerant gas phase storage tank 06 through a gas booster pump 75 and a one-way pipeline respectively. The spray tower 02 includes a nozzle 21 connected to a liquid hydrogen booster pipeline and a coil heat exchanger 22 for circulating a liquid phase refrigerant in the tower. The refrigerant liquid phase storage tank 07 includes a wire mesh filter 77 installed on the upper part of the tank body and a pressure transmitter 78 installed on the top of the tank body.

[0031] The first to eighth shut-off valves are installed between the liquid hydrogen storage bottle 01 and the hydraulic booster pump 12, between the spray tower 02 and the refrigerant liquid phase storage tank 07, on the output pipeline of the high-pressure vaporizer 03, on the pipeline leading to the hydrogen storage bottle group 04, on the input pipeline of the hydrogen heat exchanger 08, between the refrigerant liquid phase storage tank 07 and the liquid circulation pump 72, between the refrigerant liquid phase storage tank 07 and the refrigerant gas phase storage tank 06, and between the hydrogen heat exchanger 08 and the refrigerant gas phase storage tank 06; a regulating valve 61 is installed between the refrigerant gas phase storage tank 06 and the spray tower 02; the first and second one-way valves are installed on the output pipeline of the high-pressure vaporizer 03 and on the refrigerant output pipeline of the hydrogen heat exchanger 08; the first and second temperature transmitters are installed between the spray tower 02 and the refrigerant liquid phase storage tank 07 and at the hydrogen outlet of the hydrogen heat exchanger 08.

[0032] The whole station control cabinet is set in the liquid hydrogen station room, and the whole station control unit is set in the whole station control cabinet. The whole station control unit is a PLC controller and three inverters electrically connected to it, including the following connections and functions: (1) The whole station control unit is electrically connected to the emergency stop button. When an emergency occurs, the staff can press the emergency stop button to enable the whole station control unit to receive the emergency stop signal from the emergency stop button and interlock the whole station emergency stop; (2) The hydrogen detector is electrically connected to the whole station control unit so that the whole station control unit can receive the alarm data of the on-site hydrogen detector in real time and interlock the relevant equipment to shut down according to the alarm data; (3) The flame detector is electrically connected to the whole station control unit so that the whole station control unit receives the alarm signal of the flame detector in real time and interlocks the whole station for emergency stop according to the alarm signal; (4) The on-site pump body is electrically connected to the frequency converter so that the entire station control unit can control the start, stop and speed regulation of the frequency converter through Modbus-RTU communication, thereby realizing the start, stop and speed regulation of the pump; (5) The pressure transmitter is electrically connected to the whole station control unit so that the whole station control unit receives the pressure data of the pressure transmitter; (6) The temperature transmitter is electrically connected to the whole station control unit so that the whole station control unit receives the temperature data from the temperature transmitter; (7) The shut-off valve is electrically connected to the whole station control unit so that the whole station control unit can control the conduction and disconnection of the shut-off valve; (8) The regulating valve is electrically connected to the whole station control unit, and the whole station control unit controls the 0-100% opening of the regulating valve through Modbus-RTU communication; (9) The gas hydrogen storage bottle is electrically connected to the whole station control unit, and the whole station control unit receives the real-time pressure detection value of the gas hydrogen storage bottle through a 4-20mA analog signal; (10) The hydrogenation system is electrically connected to the whole station control unit so that the whole station control unit receives real-time data of the hydrogenation system through Modbus-RTU communication; (11) The sound and light alarm is electrically connected to the control unit of the entire station. When an alarm occurs in the system, the control unit of the entire station will interlock the sound and light alarm to alert the staff to check and handle the situation.

[0033] During operation, the hydrogen storage and cold storage process is controlled and implemented according to the following process: (1) System detection: The control system is in automatic mode, there is no emergency stop, and all valves are closed; (2) Liquid hydrogen pressurization: When the control unit detects that the pressure of the gas hydrogen storage tank is less than the starting filling set value, it opens the first shut-off valve 11, the second shut-off valve 24, the third shut-off valve 31, and the fourth shut-off valve 32, and starts the first inverter to operate the liquid hydrogen booster pump 12, and pressurizes the liquid hydrogen in the liquid hydrogen storage tank 01 to 45Mpa through the liquid hydrogen booster pump 12. The pressurized liquid hydrogen is transported to the spray tower 02; (3) Cold energy exchange: Liquid hydrogen passes through the spray tower 02, and is atomized into small droplets by the nozzle 21 at the top of the tower, and is heat-exchanged with the gas-phase refrigerant through the coil heat exchanger 22; (4) Refrigerant liquefaction: The gas phase refrigerant absorbs the cold energy of the liquid hydrogen in the coil heat exchanger 22, and the temperature decreases until a phase change occurs. During the phase change process, the refrigerant stores a large amount of cold energy and is converted into a liquid phase refrigerant, which flows into the refrigerant liquid phase storage tank 07; (5) Temperature control of the cold storage device: The control unit opens the regulating valve 61 according to the preset opening, and monitors the temperature of the cold storage agent leading to the cold storage agent liquid phase storage tank 07 in real time through the first temperature transmitter. When the temperature exceeds -60°C, the regulating valve 61 is interlocked to open, and when it is lower than -80°C, the regulating valve 61 is closed, and the opening of the regulating valve 61 is dynamically adjusted to keep the temperature of the liquid phase cold storage agent between -60°C and -80°C; (6) Pressure regulation of cold storage device: When the liquid-phase refrigerant enters the refrigerant liquid-phase storage tank 07, it will inevitably carry some gas-phase refrigerant, causing the pressure in the refrigerant liquid-phase storage tank 07 to increase. The control unit monitors the value of the pressure transmitter 78 in the gas phase space of the refrigerant liquid-phase storage tank in real time. When the value of the pressure transmitter 78 exceeds the start-up setting value, the control unit controls the seventh shut-off valve 74 to open, and at the same time interlocks and starts the third frequency converter to start the gas booster pump 75, pressurizes the gas-phase refrigerant in the gas phase space and transports it to the refrigerant gas-phase storage tank 06; when the value of the pressure transmitter 78 is lower than the start-up setting value, the control unit controls the seventh shut-off valve 74 and the third frequency converter to close, so that the gas booster pump 75 is also closed; (7) Liquid hydrogen vaporization: In the spray tower 02, the liquid hydrogen releases cold energy and partially vaporizes, and the unvaporized portion continues to vaporize after entering the high-pressure vaporizer; (8) Hydrogen storage and termination: Liquid hydrogen is completely vaporized into hydrogen gas through the high-pressure vaporizer 03 and transported to the hydrogen storage bottle 04 through a pipeline. When the control unit detects that the hydrogen storage bottle 04 is full, the first shut-off valve 11, the third shut-off valve 31 and the liquid hydrogen booster pump 12 are closed; the second shut-off valve 24 and the regulating valve 61 are closed.

[0034] The hydrogenation process is controlled and implemented according to the following process: (1) System detection: The control system is in automatic mode, there is no emergency stop, and all valves are closed; (2) Precooling: To improve the refueling efficiency, hydrogen is first added to the hydrogen vehicle through the gas hydrogen storage bottle 04 during hydrogen refueling. When the control unit receives the start signal of the hydrogen refueling system 05, it controls the opening of the 4th shut-off valve 32 and the 5th shut-off valve 33 to allow the hydrogen in the gas hydrogen storage bottle 04 to enter the pipe side of the hydrogen heat exchanger 08. At the same time, it controls the opening of the 6th shut-off valve 71 and the 8th shut-off valve 82, and starts the 2nd inverter to open the liquid circulation pump 72 and operate at low power to transport the refrigerant in the refrigerant liquid phase storage tank 07 to the shell side of the hydrogen heat exchanger 08. In the hydrogen heat exchanger 08, the gaseous hydrogen exchanges heat with the liquid phase refrigerant. The liquid phase refrigerant releases cold energy and its temperature rises, and is converted into the gas phase. A large amount of cold energy is released during the phase change process, and the hydrogen absorbs the cold energy and its temperature decreases. (3) Gas-hydrogen temperature control: The control unit detects the value of the second temperature transmitter in real time, that is, the temperature of the hydrogen at the hydrogen outlet of the hydrogen heat exchanger, and automatically adjusts the frequency of the second frequency converter to adjust the power of the liquid circulation pump 72. When the hydrogen temperature is higher than 0°C, the power of the liquid circulation pump 72 is increased to reduce the hydrogen temperature; when the hydrogen temperature is lower than -10°C, the power of the liquid circulation pump 72 is reduced to increase the hydrogen temperature. This ensures that the hydrogen temperature at the outlet of the hydrogen heat exchanger 08 is maintained at -10°C to 0°C; (4) Hydrogenation: The gas phase refrigerant after heat exchange enters the refrigerant gas phase storage 06 under the action of pressure difference, and the pre-cooled hydrogen enters the hydrogen supply system 05 and completes the filling of the vehicle; (5) Stop hydrogen supply: When the control unit receives the signal that the hydrogenation system 05 is completed, the 4th, 5th, 6th and 8th shut-off valves are closed and the 2nd inverter is stopped, and the liquid circulation pump is turned off, and the hydrogenation process ends.

[0035] In this example, the large amount of cold energy released by the gasification of liquid hydrogen is recovered and utilized through a refrigerant storage agent, thereby simplifying the pre-cooling device, reducing the investment in the liquid hydrogen station, lowering energy consumption, and saving energy.

[0036] Although some preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0037] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of its inventive concept. Thus, if these modifications and variations of the present invention fall within the scope of the claims of this application and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A liquid hydrogen filling station, comprising a liquid hydrogen storage tank, a filling system and a control unit, wherein the filling system comprises a high-pressure vaporizer installed in the output pipeline of the liquid hydrogen storage tank, a gas hydrogen storage bottle connected to the output pipeline of the high-pressure vaporizer and a hydrogenation system, characterized in that: It also includes a cold energy recovery system, which includes a spray tower installed between the liquid hydrogen storage tank and the high-pressure vaporizer, and a hydrogen heat exchanger installed on the input pipeline of the hydrogenation system. A refrigerant liquid phase storage tank is installed on the refrigerant liquid phase pipeline between the spray tower and the hydrogen heat exchanger, and a refrigerant gas phase storage tank is installed on the refrigerant gas phase pipeline between the spray tower and the hydrogen heat exchanger. The top of the refrigerant liquid phase storage tank is connected to the input end of the refrigerant gas phase storage tank.

2. The liquid hydrogen filling station according to claim 1, characterized in that: The spray tower comprises a tower body, a nozzle installed on the top of the tower body and connected to the boost output pipeline of the liquid hydrogen storage tank, and a coil heat exchanger installed in the spray tower.

3. The liquid hydrogen filling station according to claim 1, characterized in that: The refrigerant liquid phase storage tank comprises a tank body, a wire mesh filter installed on the upper part of the tank body, and a pressure transmitter installed on the top of the tank body; the refrigerant liquid phase storage tank is a vacuum multi-layer insulation structure to prevent the loss of refrigerant cold energy.

4. The liquid hydrogen filling station according to claim 1, characterized in that: The liquefaction temperature of the refrigerant liquid is -50°C to -30°C.

5. The liquid hydrogen filling station according to claim 1, characterized in that: The control unit includes a PLC controller and several frequency converters electrically connected to the PLC controller; the control unit is electrically connected to the hydrogen detector, flame detector, temperature transmitter and pressure transmitter in the signal detection device, is electrically connected to the emergency stop button in the action input device, and is electrically connected to the sound and light alarm, shut-off valve, regulating valve and pump body in the action execution device.

6. A hydrogenation method, comprising a safety control process and a hydrogenation process, characterized in that: The liquid hydrogen filling station according to claim 1 is implemented, and also includes the following automatic cold storage and hydrogen storage process: (1) Liquid hydrogen pressurization: When the control unit detects that the pressure of the gas hydrogen storage bottle is less than the starting filling set value, the interlock opens the relevant valves of the hydrogen storage and cold storage pipelines and starts the liquid hydrogen booster pump to pressurize the liquid hydrogen in the liquid hydrogen storage bottle and input it into the pipeline; (2) Cold energy exchange: Liquid hydrogen passes through the spray tower, and is atomized into small droplets through the nozzle at the top of the tower, and heat is exchanged with the gas phase refrigerant through the coil heat exchanger; (3) Refrigerant liquefaction: The gas phase refrigerant absorbs the cold energy of liquid hydrogen in the coil heat exchanger and then liquefies and flows into the refrigerant liquid phase storage tank; (4) Temperature control of cold storage device: The control unit dynamically adjusts the opening of the regulating valve according to the temperature of the cold storage liquid tank. When the temperature exceeds the maximum cold storage temperature, the regulating valve is interlocked to open, and when the temperature is lower than the minimum cold storage temperature, the regulating valve is closed to maintain the temperature of the liquid cold storage in a constant range. (5) Pressure regulation of cold storage device: The pressure of the cold storage tank will increase due to the gaseous components entrained when the liquid cold storage enters. When the control unit detects that the pressure exceeds the set value, the relevant valves of the pressure reducing pipeline are interlocked to open and the gas booster pump is started to pressurize the gaseous cold storage tank into the cold storage tank; when the pressure is lower than the threshold, the relevant actuator is automatically closed; (6) Liquid hydrogen vaporization: In the spray tower, liquid hydrogen releases cold energy and partially vaporizes, and the unvaporized part continues to vaporize after entering the high-pressure vaporizer; (7) Hydrogen storage and termination: Liquid hydrogen is completely vaporized into hydrogen gas through a high-pressure vaporizer and transported to the hydrogen storage bottle through a pipeline. When the control unit detects that the hydrogen storage bottle is full, the relevant valves of the hydrogen storage and cold storage pipelines and the liquid hydrogen booster pump are closed in a chain manner.

7. The hydrogenation method according to claim 6, characterized in that The safety control process includes: (1) When an emergency occurs, the staff can press the emergency stop button so that the control unit receives the emergency stop signal from the emergency stop button and interlocks the emergency stop of the entire station equipment; (2) The control unit receives the alarm data of the hydrogen detector in real time and interlocks the shutdown of related equipment according to the alarm data; (3) The control unit receives the alarm signal from the flame detector in real time and interlocks the entire station for emergency shutdown according to the alarm signal; (4) When the system alarm occurs, the control unit will interlock the sound and light alarm.

8. The hydrogenation method according to claim 6, characterized in that The hydrogenation process comprises: (1) Precooling: When the control unit receives the start-up signal of the hydrogenation system, it opens the valves related to the hydrogenation and precooling pipelines and starts the liquid circulation pump, so that the liquid phase refrigerant enters the shell side of the hydrogen heat exchanger to exchange heat with the hydrogen supplied from the hydrogen storage bottle into the tube side of the hydrogen heat exchanger; (2) Gas-hydrogen temperature control: The liquid phase refrigerant releases cold energy and its temperature rises, and is converted into the gas phase. During the phase change, cold energy is released, and hydrogen absorbs cold energy, causing the temperature to drop. The control unit detects the hydrogen temperature at the hydrogen outlet of the hydrogen heat exchanger in real time, and automatically adjusts the operating speed of the liquid circulation pump to keep the hydrogen temperature within the set range. (3) Hydrogenation: The gas phase refrigerant after heat exchange enters the refrigerant gas phase storage, and the pre-cooled hydrogen enters the hydrogen supply system and completes the refueling of the vehicle; (4) Stop supplying hydrogen: When the control unit receives the signal that the hydrogenation system has been filled, it interlocks and closes the valves related to the hydrogenation and precooling pipelines and turns off the liquid circulation pump, and the hydrogenation process ends.

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