Hydrogen pre-cooling filling system, liquid hydrogen hydrogen filling station and control method

Abstract

The application belongs to the technical field of hydrogen energy and fuel cell vehicles, and relates to a hydrogen pre-cooling filling system, a liquid hydrogen hydrogenation station and a control method. The liquid hydrogen hydrogenation station comprises a main pipeline arranged between a liquid hydrogen storage tank and a hydrogenation machine, a main pipeline control valve, a fin gasifier, a hydrogen storage bottle group and a blending temperature mixing tank arranged on the main pipeline in sequence. The cold box is connected to the liquid hydrogen storage tank through a branch pipeline to obtain cold energy from the liquid hydrogen and store the cold energy. The cold box is also connected to the main pipeline section between the hydrogen storage bottle group and the hydrogenation machine through a shunt joint. The cold box releases cold energy to cool hydrogen flowing through the shunt. The blending temperature mixing tank is arranged at the connection between a high-temperature hydrogen outlet pipeline and the main pipeline section, and is used for mixing high-temperature hydrogen and cooled hydrogen to be delivered to the hydrogenation machine. Compared with the prior art, the hydrogen pre-cooling filling system structure is simplified, the land occupation area of the liquid hydrogen hydrogenation station is reduced, the problem of icing failure of the liquid cold carrier is avoided, and the liquid hydrogen cold energy recovery efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen energy and fuel cell vehicle technology, and relates to a hydrogen pre-cooling refueling system, a liquid hydrogen refueling station and a control method. Background Technology

[0002] Vigorously developing hydrogen energy is one of the important measures to achieve energy structure transformation and sustainable development. Hydrogen refueling stations are the infrastructure for replenishing the energy supply of hydrogen energy utilization equipment such as hydrogen fuel cells, and are an important prerequisite for the promotion and application of fuel cell vehicles and the accelerated development of the hydrogen energy industry. This is in accordance with the "Technical Roadmap for Energy-Saving and New Energy Vehicles" revised and compiled by the China Society of Automotive Engineers under the guidance of the Ministry of Industry and Information Technology on October 27, 2020. Figure 2 According to the relevant plans of "0", my country aims to build at least 1,000 hydrogen refueling stations by 2025 and at least 5,000 by 2035.

[0003] Depending on the hydrogen storage state, hydrogen refueling stations can be divided into gaseous hydrogen refueling stations and liquid hydrogen refueling stations. Due to the higher density of liquid hydrogen, the volume of a liquid hydrogen storage tank is much smaller than that of a high-pressure gaseous hydrogen storage tank for the same amount of hydrogen stored, significantly reducing the footprint of the refueling station. Furthermore, liquid hydrogen offers advantages such as high storage and transportation efficiency, low transportation costs, and high hydrogen purity. Therefore, liquid hydrogen refueling stations are more suitable for large-scale hydrogen refueling operations. According to H2Stations' global hydrogen refueling station statistics report, as of 2021, more than 800 hydrogen refueling stations had been built worldwide, 30% of which were liquid hydrogen refueling stations, mainly located in the United States, Europe, and Japan. LINDE, a German company, is a pioneer in the research, application, and promotion of liquid hydrogen refueling stations. Their pressurized vaporization liquid hydrogen refueling station in Oakland, California, has an on-site hydrogen storage capacity of 800 kg and a refueling capacity exceeding 40 kg / h (~0.67 kg / min), capable of simultaneously meeting hydrogen refueling requirements at 35 MPa and 70 MPa. However, constrained by a series of issues related to liquid hydrogen production, storage, transportation, and safety, research on liquid hydrogen refueling stations in my country is still in its early stages. The required key equipment technologies are immature, and safety performance assessments are insufficient.

[0004] During high-pressure hydrogen refueling, the Joule-Thomson effect and the resulting heat of compression can cause the hydrogen in the fuel cell vehicle's onboard hydrogen storage tank to heat up rapidly, posing a serious safety hazard. In practical applications, a refrigeration unit is typically used to pre-cool the hydrogen during refueling to control its temperature and ensure safety. This inevitably requires a significant amount of electrical energy for hydrogen pre-cooling.

[0005] Liquid hydrogen refueling stations use liquid hydrogen as their storage medium. Due to its extremely low storage temperature (~-253℃), liquid hydrogen contains a significant amount of cold energy. However, currently, fuel cell vehicles operating domestically and internationally all use ambient temperature gaseous hydrogen as fuel, with few reports of using liquid hydrogen. This necessitates that liquid hydrogen be vaporized at refueling stations before it can be used to refuel fuel cell vehicles. The vaporization and heating process releases a large amount of cold energy. Existing liquid hydrogen refueling stations abroad, such as the Ariake refueling station in Tokyo, Japan, and the liquid hydrogen refueling stations built by Plug Power for Walmart and Amazon in the United States, all use ambient temperature vaporizers. In these vaporizers, liquid hydrogen exchanges heat with air and vaporizes, heating up the air. The air gains cold energy, which is then released into the atmosphere, resulting in a waste of the liquid hydrogen's cold energy. If this cold energy could be effectively utilized to pre-cool the input hydrogen to the refueling machine, the energy consumption of the refueling station system could be significantly reduced, improving the economic efficiency of the liquid hydrogen refueling station. CN 113531388 A and CN 112682691A disclose a cold energy recovery system that can avoid the waste of liquid hydrogen cold energy. However, the separate design of the heat exchanger and the cold storage device complicates the cold energy recovery system, resulting in low reliability and reduced efficiency of cold energy recovery. Therefore, designing a pre-cooling refueling system that can simply and effectively utilize liquid hydrogen cold energy to pre-cool the input hydrogen gas of the hydrogen refueling machine has high practical application value.

[0006] To address the aforementioned needs, this invention innovatively proposes a hydrogen pre-cooling refueling system and control strategy for liquid hydrogen refueling stations. Liquid hydrogen refueling stations using this system can more effectively utilize the cold energy contained in liquid hydrogen for pre-cooling hydrogen refueling of fuel cell vehicles, thereby saving energy consumption of the refrigeration unit and improving the economic efficiency of liquid hydrogen refueling stations. Summary of the Invention

[0007] The purpose of this invention is to provide a hydrogen pre-cooling refueling system, a liquid hydrogen refueling station, and a control method, which uses the cooling energy of liquid hydrogen for the pre-cooling of refueling hydrogen, thereby meeting the low-energy consumption, high-flow-rate, and rapid refueling requirements of liquid hydrogen refueling stations.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] A hydrogen precooling and refueling system includes a cold box, a low-temperature hydrogen inlet pipeline and a low-temperature hydrogen outlet pipeline, a high-temperature hydrogen inlet pipeline and a high-temperature hydrogen outlet pipeline, and a mixing and temperature adjustment tank.

[0010] The cold side of the cold box is connected to a liquid hydrogen source via a low-temperature hydrogen inflow pipeline and to a liquid hydrogen vaporizer via a low-temperature hydrogen outflow pipeline, thereby absorbing and storing the cold energy in the liquid hydrogen; the low-temperature hydrogen flowing out of the cold box enters the liquid hydrogen vaporizer for heating and vaporization to obtain hydrogen gas, which can be stored in a hydrogen storage cylinder group.

[0011] The hot side of the cold box is connected to the outlet of the hydrogen storage cylinder group via a high-temperature hydrogen inflow pipeline and to the mixing and temperature adjustment tank via a high-temperature hydrogen outflow pipeline; the outlet of the hydrogen storage cylinder group is also connected to the mixing and temperature adjustment tank; that is, part of the high-temperature hydrogen released from the hydrogen storage cylinder group enters the cold box for cooling to obtain cold hydrogen, and the other part enters the mixing and temperature adjustment tank to mix with the cold hydrogen and adjust the temperature to obtain hydrogen that meets the temperature required for pre-cooling and filling.

[0012] The outlet of the mixing and temperature-controlled tank is connected to the hydrogen dispenser, which can output hydrogen gas that meets the temperature required for pre-cooling and refueling through the hydrogen dispenser.

[0013] A liquid hydrogen refueling station includes a liquid hydrogen storage tank, a cold box and a hydrogen dispenser connected by pipelines. In addition, the liquid hydrogen refueling station also includes a main pipeline between the liquid hydrogen storage tank and the hydrogen dispenser, and a main pipeline control valve, a finned vaporizer, a hydrogen storage cylinder group and a mixing and temperature matching tank arranged sequentially on the main pipeline.

[0014] The cold box and the main pipeline control valve are connected in parallel via a cryogenic hydrogen inflow pipeline and a cryogenic hydrogen outflow pipeline, so that the cold box can obtain and store cold energy from the liquid hydrogen released from the liquid hydrogen storage tank; a cold storage control valve is provided on the cryogenic hydrogen inflow pipeline.

[0015] The cold box is also connected in parallel to the main pipeline between the hydrogen storage cylinder group and the hydrogen dispenser via a high-temperature hydrogen inflow pipeline and a high-temperature hydrogen outflow pipeline. A bypass control valve is provided on the high-temperature hydrogen inflow pipeline.

[0016] A diversion connector is provided between the high-temperature hydrogen inflow pipeline and the main pipeline for diverting the hydrogen released from the hydrogen storage cylinder group. The cold box releases cold energy to cool the diverted hydrogen. The mixing and temperature-regulating tank is located at the connection between the high-temperature hydrogen outflow pipeline and the main pipeline for mixing the undiverted hydrogen with the cooled hydrogen to form hydrogen gas that meets the temperature required for pre-cooling and refueling, so as to deliver it to the hydrogen dispenser for output.

[0017] Furthermore, a compressor is also provided between the finned vaporizer and the hydrogen storage cylinder assembly.

[0018] Furthermore, the finned vaporizer is an aluminum finned tube vaporizer.

[0019] Furthermore, the liquid hydrogen refueling station also includes a tube vaporizer, which is located between the liquid hydrogen storage tank and the finned vaporizer.

[0020] Furthermore, the outlet of the liquid hydrogen storage tank is also connected to a liquid hydrogen booster pump.

[0021] Furthermore, the refrigerant used in the cold box is either solid or liquid.

[0022] A control method for a liquid hydrogen refueling station includes:

[0023] Cold energy acquisition: When the temperature inside the cold box is higher than the set low temperature, the cold storage control valve is opened. Low temperature hydrogen flows into the cold box through the low temperature hydrogen inflow pipeline and exchanges heat with the refrigerant. Then it flows out of the cold box through the low temperature hydrogen outflow pipeline. The refrigerant obtains cold energy and stores it until the temperature inside the cold box reaches the set low temperature. Then the cold storage control valve is closed and the low temperature hydrogen stops flowing into the cold box.

[0024] Pre-cooling refueling: When there is a need for hydrogen refueling, the bypass control valve is opened to split the hydrogen in the main pipeline through the split connector. Part of it flows into the cold box and is cooled by the refrigerant to obtain cold hydrogen. The other part is mixed with the cold hydrogen in the mixing and temperature matching tank to obtain hydrogen that meets the temperature required for pre-cooling refueling, and then output from the hydrogen dispenser.

[0025] The required temperature for pre-cooling refueling is -40℃.

[0026] Furthermore, the liquid hydrogen refueling station also includes a controller. During the pre-cooling refueling process, when there is a need for hydrogen refueling, the controller adjusts the flow rate of hydrogen in the main pipeline and the diversion ratio of the diversion connector according to the required hydrogen refueling rate, the pre-cooling temperature of the refueling hydrogen, the room temperature, and the real-time temperature in the cold box.

[0027] Furthermore, the liquid hydrogen refueling station also includes a control method, which further includes:

[0028] Ambient temperature storage: Open the main pipeline control valve to allow the low-temperature hydrogen in the liquid hydrogen storage tank to flow through the finned vaporizer and be converted into gaseous hydrogen, which is then stored in the hydrogen storage cylinder group;

[0029] Real-time control: During the hydrogen refueling process, the controller dynamically adjusts the hydrogen splitting ratio at the splitting connector in the hydrogen storage cylinder group according to the real-time temperature in the cold box, so that the temperature after mixing and warming reaches the pre-cooling temperature required for hydrogen refueling.

[0030] This invention provides a hydrogen pre-cooling and refueling system for liquid hydrogen refueling stations, comprising a cold box that combines heat exchange and cold storage functions, a hydrogen bypass pipeline, a blending and temperature mixing tank, and a hydrogen dispenser. Low-temperature hydrogen passes through the cold box, exchanging its cold energy with a refrigerant stored within. Room-temperature hydrogen passes through the cold box, gaining cold energy from the refrigerant and being cooled to the same temperature as the refrigerant. It is then blended with room-temperature hydrogen at the same pressure in the main pipeline to the required pre-cooling and refueling temperature before being dispensed via the hydrogen dispenser. This invention enables liquid hydrogen refueling stations to achieve rapid pre-cooling of refueling hydrogen without the need for additional refrigeration equipment, reducing overall station energy consumption. Furthermore, with a suitable pre-cooling and refueling strategy, only a cold box combining heat exchange and cold storage functions, a bypass pipeline, and a blending and temperature mixing tank are required, simplifying the system structure of liquid hydrogen refueling stations and facilitating their promotion and application.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1) Simplified structure of hydrogen precooling and refueling system: The present invention integrates the heat exchanger for obtaining liquid hydrogen cold energy, the cold box for storing the refrigerant and the heat exchanger for precooling hydrogen into a cold box with both heat exchange and cold storage functions, and there is no need to set up a circulation pump to circulate the refrigerant between the cold box and the heat exchanger, thus simplifying the hydrogen precooling and refueling system.

[0033] 2) Avoiding the problem of liquid refrigerant freezing and failure: Since the refrigerant needs to circulate between the cold box and the heat exchanger, conventional liquid hydrogen refueling station cold energy utilization systems use liquid refrigerants. However, the freezing point of commonly used liquid refrigerants is much higher than the temperature of liquid hydrogen (~-253℃). On the one hand, this poses a risk of refrigerant freezing; on the other hand, because the cold box needs to be maintained at a temperature much higher than the liquid hydrogen temperature range, it is difficult to make full use of liquid hydrogen cold energy. In the hydrogen pre-cooling refueling system of the present invention, since the cold box also has the function of heat exchange, the refrigerant in the cold box can be a non-flowing solid substance, eliminating the freezing and failure problem of liquid refrigerants. This greatly expands the operating temperature range of the cold box, making it easier to make full use of liquid hydrogen cold energy. The lower cold box temperature is also beneficial for rapid pre-cooling of large-flow hydrogen refueling.

[0034] 3) Reduced footprint of liquid hydrogen refueling stations: Solid refrigerant cold boxes with the same cooling capacity are smaller in volume, which can reduce the footprint of liquid hydrogen refueling stations and help promote their application in cities with scarce land resources.

[0035] 4) Improve the efficiency of liquid hydrogen cold energy recovery: When adding hydrogen at high flow rates, the cold box, which combines heat exchange and cold storage functions, cannot pre-cool the large amount of gaseous hydrogen instantaneously, resulting in the inability to accurately pre-cool to -40℃. Therefore, this invention proposes a method of temperature control by mixing low-temperature gaseous hydrogen and room-temperature gaseous hydrogen, using room-temperature gaseous hydrogen to help improve the efficiency of liquid hydrogen cold energy recovery. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a hydrogen pre-cooling and refueling system according to the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of a hydrogen pre-cooling and refueling system for a liquid hydrogen refueling station in Example 1;

[0038] Figure 3 This is a schematic diagram of the structure of a hydrogen pre-cooling and refueling system for a liquid hydrogen refueling station in Example 2;

[0039] Figure 4 This is a schematic diagram of the structure of a hydrogen pre-cooling and refueling system for a liquid hydrogen refueling station in Example 3;

[0040] Explanation of markings in the diagram:

[0041] 1-Cold box, 2-Blending and temperature mixing tank, 3-Hydrogen dispenser, 4-Liquid hydrogen storage tank, 5-Ambient vaporizer, 51-Bare tube vaporizer, 52-Finned vaporizer, 6-Compressor, 7-Hydrogen storage cylinder group, 8-Liquid hydrogen booster pump, 11-Cryogenic hydrogen inflow pipeline, 12-Cryogenic hydrogen outflow pipeline, 13-High temperature hydrogen inflow pipeline, 14-High temperature hydrogen outflow pipeline, 15-Main pipeline, 21-Cryogenic storage control valve, 22-Bypass control valve, 23-Main pipeline control valve. Detailed Implementation

[0042] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are based on the above-described technical solutions of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0044] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0045] Depending on the equipment used, liquid hydrogen refueling stations can employ two methods for pressurizing and vaporizing liquid hydrogen: vaporization followed by pressurization and pressurization followed by vaporization. The former involves first vaporizing liquid hydrogen into low-pressure gaseous hydrogen, then pressurizing it to a specified high-pressure gaseous hydrogen using a compressor. The latter involves first pressurizing the liquid hydrogen to a specified pressure using a liquid hydrogen booster pump, then vaporizing it into high-pressure gaseous hydrogen using a vaporizer. Early liquid hydrogen refueling stations mostly used the first method, but with the development of liquid hydrogen booster pump technology, more and more liquid hydrogen refueling stations are now adopting the latter method.

[0046] like Figure 1 The hydrogen precooling and refueling system shown includes a cold box 1, a low-temperature hydrogen inflow pipeline 11 and a low-temperature hydrogen outflow pipeline 12, a high-temperature hydrogen inflow pipeline 13 and a high-temperature hydrogen outflow pipeline 14, and a mixing and temperature adjustment tank 2.

[0047] The cold side of the cold box 1 is connected to a liquid hydrogen source via a low-temperature hydrogen inflow pipe 11 and a liquid hydrogen vaporizer via a low-temperature hydrogen outflow pipe 12, thereby absorbing and storing the cold energy in the liquid hydrogen. The low-temperature hydrogen flowing out of the cold box 1 enters the liquid hydrogen vaporizer for heating and vaporization to obtain hydrogen gas. The hot side of the cold box 1 is connected to the outlet of the hydrogen storage cylinder group via a high-temperature hydrogen inflow pipe 13 and a high-temperature hydrogen outflow pipe 14, and is connected to the mixing and temperature adjustment tank 2. The outlet of the hydrogen storage cylinder group is also connected to the mixing and temperature adjustment tank 2. That is, part of the high-temperature hydrogen released from the hydrogen storage cylinder group enters the cold box 1 for cooling to obtain cold hydrogen, and the other part enters the mixing and temperature adjustment tank 2 to mix with the cold hydrogen and adjust the temperature to obtain hydrogen gas that meets the temperature required for pre-cooling and refueling. The outlet of the mixing and temperature adjustment tank 2 is connected to the hydrogen dispenser 3, so that the hydrogen gas that meets the temperature required for pre-cooling and refueling can be output to the outside through the hydrogen dispenser 3.

[0048] like Figures 2-4 The liquid hydrogen refueling station shown includes a liquid hydrogen storage tank 4, a cold box 1 and a hydrogen dispenser 3 connected by pipelines. In addition, the liquid hydrogen refueling station also includes a main pipeline 15 located between the liquid hydrogen storage tank 4 and the hydrogen dispenser 3, and a main pipeline control valve 23, a finned vaporizer 52, a hydrogen storage cylinder group 7 and a mixing and temperature mixing tank 2 arranged sequentially on the main pipeline 15.

[0049] Cold box 1 combines heat exchange and cold storage functions:

[0050] Cold storage function: The cold box 1 and the main pipeline control valve 23 are connected in parallel through a low-temperature hydrogen inflow pipeline 11 and a low-temperature hydrogen outflow pipeline 12, so that the cold box 1 can obtain and store cold energy from the liquid hydrogen released from the liquid hydrogen storage tank 4; a cold storage control valve 21 is provided on the low-temperature hydrogen inflow pipeline 11.

[0051] Heat exchange function: The cold box 1 is also connected in parallel to the main pipeline between the hydrogen storage cylinder group 7 and the hydrogen dispenser 3 via a high-temperature hydrogen inflow pipeline 13 and a high-temperature hydrogen outflow pipeline 14. A bypass control valve 22 is provided on the high-temperature hydrogen inflow pipeline 13. A diversion connector is provided between the high-temperature hydrogen inflow pipeline 13 and the main pipeline for diverting the hydrogen released from the hydrogen storage cylinder group 7. The cold box 1 releases cold energy to cool the diverted hydrogen. The mixing and temperature matching tank 2 is located at the connection between the high-temperature hydrogen outflow pipeline 14 and the main pipeline for mixing the high-temperature hydrogen with the cooled hydrogen for delivery to the hydrogen dispenser 3 for external output.

[0052] In this invention, "low temperature" and "high temperature" refer only to the hydrogen in the low temperature hydrogen inflow pipe 11 and the low temperature hydrogen outflow pipe 12, and the hydrogen in the high temperature hydrogen inflow pipe 13 and the high temperature hydrogen outflow pipe 14, respectively, and represent the relative temperature of the two.

[0053] In some specific embodiments, the low-temperature hydrogen flowing into the cold box 1 through the low-temperature hydrogen inflow pipe 11 can be low-pressure liquid hydrogen at 0.2-0.9 MPa and -253--243°C, high-pressure liquid hydrogen at 20-90 MPa and -253--240°C, or high-pressure gaseous hydrogen at 20-90 MPa and -40-85°C. The high-temperature hydrogen flowing into the cold box 1 through the high-temperature hydrogen inflow pipe 13 is high-pressure gaseous hydrogen at 20-90 MPa and room temperature.

[0054] In some specific embodiments, the cold box 1 is equipped with pipes for low-temperature hydrogen and pipes for high-temperature hydrogen. The cold box 1 is filled with a refrigerant, and the pipes are in close contact with the refrigerant to improve heat exchange efficiency. The cold box 1 is equipped with a temperature sensor for detecting the temperature of the refrigerant, and the temperature sensor is connected to the central processing unit.

[0055] In some specific embodiments, a compressor 6 is also provided between the finned vaporizer 52 and the hydrogen storage cylinder group 7, and high-pressure hydrogen is obtained by the compressor 6 and stored in the hydrogen storage cylinder group 7.

[0056] In some specific embodiments, the finned vaporizer 52 is a finned sleeve vaporizer; more preferably, the finned vaporizer 52 is an aluminum finned sleeve vaporizer. Even more preferably, the hydrogen vaporized by the aluminum finned sleeve vaporizer is at room temperature, so as to facilitate storage in the hydrogen storage cylinder group 7.

[0057] In some specific embodiments, the liquid hydrogen refueling station also includes a bare tube vaporizer 51. Preferably, the bare tube vaporizer 51 is located between the outlet end of the cryogenic hydrogen outflow pipeline 12 and the finned vaporizer 52 to cooperate with the finned vaporizer 52 for multi-stage heating, such as... Figure 3 As shown. More preferably, the smooth tube vaporizer 51 is a smooth stainless steel tube vaporizer.

[0058] More preferably, when it is necessary to regulate the temperature of the liquid hydrogen entering the cold box 1, the light tube vaporizer 51 is located between the liquid hydrogen storage tank 4 and the inlet end of the cryogenic hydrogen inflow pipeline 11, such as... Figure 1 , 2 As shown.

[0059] In some specific embodiments, the outlet of the liquid hydrogen storage tank 4 is also connected to a liquid hydrogen booster pump 8.

[0060] In some specific embodiments, the refrigerant used in the cold box 1 is solid or liquid, and preferably, the temperature inside the cold box 1 is not higher than -40°C.

[0061] A control method for a liquid hydrogen refueling station includes:

[0062] Cold energy acquisition: When the temperature inside the cold box 1 is higher than the set low temperature, the bypass control valve 22 is opened. Low temperature hydrogen flows into the cold box 1 through the low temperature hydrogen inflow pipe 11 and exchanges heat with the refrigerant. Then it flows out of the cold box 1 through the low temperature hydrogen outflow pipe 12. The refrigerant obtains cold energy and stores it until the temperature inside the cold box 1 reaches the set low temperature of the cold box. Then the bypass control valve 22 is closed and the low temperature hydrogen stops flowing into the cold box 1.

[0063] Pre-cooling refueling: When there is a demand for hydrogen refueling for fuel cell vehicles at the liquid hydrogen refueling station, the bypass control valve 22 is opened to split the hydrogen in the main pipeline through the split connector. Part of it flows into the cold box 1 to exchange heat with the refrigerant. The refrigerant releases cold energy, and the high-temperature hydrogen is cooled to the same temperature as the refrigerant in the cold box to obtain cold hydrogen. The other part is mixed and heated with the cold hydrogen in the mixing and temperature matching tank 2. After reaching the pre-cooling temperature for hydrogen refueling, it flows into the hydrogen refueling machine 3 through the hydrogen refueling pipeline for refueling fuel cell vehicles.

[0064] In some specific embodiments, the temperature is set to -40°C.

[0065] In some specific embodiments, the liquid hydrogen refueling station also includes a controller. During the pre-cooling refueling process, when there is a need for hydrogen refueling, the controller adjusts the flow rate of hydrogen in the main pipeline and the diversion ratio of the diversion connector according to the required hydrogen refueling rate, the pre-cooling temperature of the hydrogen being refueled, the room temperature, and the real-time temperature inside the cold box.

[0066] In some specific embodiments, the liquid hydrogen refueling station also includes a controller, and the control method further includes:

[0067] Ambient temperature storage: Open the main pipeline control valve 23 to allow the low-temperature hydrogen in the liquid hydrogen storage tank 4 to flow through the finned vaporizer 52 and be converted into gaseous hydrogen, which is then stored in the hydrogen storage cylinder group 7.

[0068] Real-time control: During the hydrogen refueling process, the controller dynamically adjusts the hydrogen splitting ratio at the splitting connector in the hydrogen storage cylinder group 7 based on the real-time temperature inside the cold box 1, so that the temperature after blending and mixing reaches the pre-cooling temperature for hydrogen refueling. For example, solenoid valves electrically connected to the controller can be installed on the pipelines after the splitting to regulate the flow rate of each pipeline.

[0069] In some specific embodiments, the controller is a central processing unit.

[0070] Example 1:

[0071] like Figure 2 The image shows a liquid hydrogen refueling station that uses a liquid hydrogen first vaporization and then pressurization mode. The cold energy source for the cold box 1 is low-pressure, low-temperature gaseous hydrogen.

[0072] (1) Pressurized vaporization: After liquid hydrogen flows out of the liquid hydrogen storage tank 4 of the liquid hydrogen refueling station, it enters the ambient temperature vaporizer 5 (including the bare tube vaporizer 51 and the finned vaporizer 52), vaporizes and heats up to room temperature, and then flows into the hydrogen storage cylinder group 7 for storage after being compressed by the compressor 6.

[0073] (2) Cold energy acquisition: Open the cold storage control valve 21 and close the main pipeline control valve 23 between the tube vaporizer 51 and the fin vaporizer 52. The low-temperature hydrogen gas (temperature of about -193℃, slightly higher than the air liquefaction temperature) after being vaporized by the tube vaporizer 51 flows into the cold box 1 through the low-temperature hydrogen inflow pipeline 11. After exchanging cold energy with the liquid refrigerant dichloromethane (freezing point of about -96.7℃) in the cold box, it flows into the fin vaporizer 52 for further vaporization and heating to room temperature. When the temperature of dichloromethane in the cold box reaches -80℃, close the cold storage control valve 21 and open the main pipeline control valve 23. The low-temperature hydrogen gas no longer flows through the cold box 1.

[0074] (3) Pre-cooling refueling: When the liquid hydrogen refueling station has a demand for 70MPa fuel cell vehicles to refuel, the central processing unit sets the appropriate hydrogen flow rate for the high-temperature hydrogen inflow pipeline 13 and the main pipeline 15 according to the required hydrogen refueling rate, the pre-cooling temperature of the refueling hydrogen (-40℃), the room temperature, and the real-time temperature in the cold box. The bypass control valve 22 is opened, and the room temperature hydrogen flows into the cold box 1 and exchanges heat with the refrigerant. The refrigerant releases cold energy, and the room temperature hydrogen is cooled to the same temperature as the refrigerant in the cold box. Then, it flows into the mixing and temperature matching tank 2 through the high-temperature hydrogen outflow pipeline 14. It mixes and temperatures the room temperature hydrogen in the mixing and temperature matching tank 2 with the room temperature hydrogen in the main pipeline 15. After reaching the pre-cooling temperature (-40℃) of the refueling hydrogen, it flows into the hydrogen refueling machine 3 through the hydrogen refueling pipeline for refueling the fuel cell vehicle.

[0075] (4) Real-time control: During the hydrogen refueling process, the central processing unit dynamically adjusts the hydrogen flow rate in the high-temperature hydrogen inlet pipe 13 and the main pipe 15 according to the real-time temperature in the cold box, so that the temperature after mixing and warming reaches the pre-cooling temperature (-40℃) of the hydrogen refueling.

[0076] Example 2:

[0077] like Figure 3 The image shows a liquid hydrogen refueling station that uses a liquid hydrogen pre-pressurization and then vaporization mode. The cold energy source for the cold box 1 is high-pressure, low-temperature gaseous hydrogen.

[0078] (1) Pressurized vaporization: After liquid hydrogen flows out of the liquid hydrogen storage tank 4 of the liquid hydrogen refueling station, it enters the liquid hydrogen booster pump 8, and after being pressurized to 90MPa, it flows into the ambient temperature vaporizer 5 (including the bare tube vaporizer 51 and the finned vaporizer 52). After vaporization and heating to room temperature, it flows into the hydrogen storage cylinder group 7 for storage.

[0079] (2) Cold energy acquisition: Open the cold storage control valve 21 and close the main pipeline control valve 23 between the bare tube vaporizer 51 and the finned vaporizer 52. The low-temperature hydrogen gas (temperature of about -193℃, slightly higher than the air liquefaction temperature) after being vaporized by the bare tube vaporizer 51 flows into the cold box 1 through the low-temperature hydrogen inflow pipeline 11. It exchanges cold energy with the liquid refrigerant dichloromethane (freezing point of about -96.7℃) in the cold box and then flows into the aluminum finned tube vaporizer 52 for further vaporization and heating to room temperature. When the temperature of dichloromethane in the cold box reaches -80℃, close the cold storage control valve 21 and open the main pipeline control valve 23. The low-temperature hydrogen gas no longer flows through the cold box 1.

[0080] (3) Pre-cooling refueling: When the liquid hydrogen refueling station has a demand for 70MPa fuel cell vehicles to refuel, the central processing unit sets the appropriate hydrogen flow rate for the high-temperature hydrogen inflow pipeline 13 and the main pipeline 15 according to the required hydrogen refueling rate, the pre-cooling temperature of the refueling hydrogen (-40℃), the room temperature, and the real-time temperature in the cold box. The bypass control valve 22 is opened, and the room temperature hydrogen flows into the cold box 1 and exchanges heat with the refrigerant dichloromethane. The dichloromethane releases cold energy, and the room temperature hydrogen is cooled to the same temperature as the refrigerant in the cold box. Then, it flows into the mixing and temperature matching tank 2 through the high-temperature hydrogen outflow pipeline 14. It mixes and matches the room temperature hydrogen in the main pipeline 15 in the mixing and temperature matching tank 2. After reaching the pre-cooling temperature (-40℃) of the refueling hydrogen, it flows into the hydrogen refueling machine 3 through the hydrogen refueling pipeline for refueling the fuel cell vehicle.

[0081] (4) Real-time control: During the hydrogen refueling process, the central processing unit dynamically adjusts the hydrogen flow rate in the high-temperature hydrogen inlet pipe 13 and the main pipe 15 according to the real-time temperature in the cold box, so that the temperature after mixing and warming reaches the pre-cooling temperature (-40℃) of the hydrogen refueling.

[0082] Example 3:

[0083] like Figure 4 The image shows a liquid hydrogen refueling station that uses a liquid hydrogen pre-pressurization and then vaporization mode. The cold energy source for the cold box 1 is high-pressure cryogenic liquid hydrogen.

[0084] (1) Pressurized vaporization: After liquid hydrogen flows out of the liquid hydrogen storage tank 4 of the liquid hydrogen refueling station, it enters the liquid hydrogen booster pump 8, and after being pressurized to 90MPa, it flows into the ambient temperature vaporizer 5 (including the bare tube vaporizer 51 and the finned vaporizer 52). After vaporization and heating to room temperature, it flows into the hydrogen storage cylinder group 7 for storage.

[0085] (2) Cold energy acquisition: Open the cold storage control valve 21 and close the main pipeline control valve 23. The 90MPa high-pressure liquid hydrogen (temperature about -253℃) after being pressurized by the liquid hydrogen booster pump 8 flows into the cold box 1 through the low-temperature hydrogen inflow pipeline 11. After exchanging cold energy with the solid refrigerant metal aluminum in the cold box, it flows into the light tube vaporizer 51 for further vaporization and heating to room temperature. When the temperature of aluminum in the cold box reaches -120℃, close the cold storage control valve 21 and open the control valve 24. The low-temperature liquid hydrogen no longer flows through the cold box 1.

[0086] (3) Pre-cooling refueling: When the liquid hydrogen refueling station has a demand for 70MPa fuel cell vehicles to refuel, the central processing unit sets a suitable hydrogen flow rate for the high-temperature hydrogen inflow pipeline 13 and the main pipeline 15 according to the required hydrogen refueling rate, the pre-cooling temperature of the refueling hydrogen (-40℃), the room temperature, and the real-time temperature in the cold box. The bypass control valve 22 is opened, and the room temperature hydrogen flows into the cold box 1 and exchanges heat with the refrigerant aluminum. The aluminum releases cold energy, and the room temperature hydrogen is cooled to the same temperature as the refrigerant aluminum in the cold box. Then, it flows into the mixing and temperature matching tank 2 through the high-temperature hydrogen outflow pipeline 14. It mixes and matches the room temperature hydrogen in the main pipeline 15 in the mixing and temperature matching tank 2. After reaching the pre-cooling temperature (-40℃) of the refueling hydrogen, it flows into the hydrogen refueling machine 3 through the hydrogen refueling pipeline for refueling the fuel cell vehicle.

[0087] (4) Real-time control: During the hydrogen refueling process, the central processing unit dynamically adjusts the hydrogen flow rate in the high-temperature hydrogen inlet pipe 13 and the main pipe 15 according to the real-time temperature in the cold box, so that the temperature after mixing and warming reaches the pre-cooling temperature (-40℃) of the hydrogen refueling.

[0088] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A control method for a liquid hydrogen refueling station, the liquid hydrogen refueling station comprising a liquid hydrogen storage tank (4), a cold box (1), and a hydrogen dispenser (3) connected by pipelines, characterized in that, The liquid hydrogen refueling station also includes a main pipeline (15) located between the liquid hydrogen storage tank (4) and the hydrogen dispenser (3), and a main pipeline control valve (23), a finned vaporizer (52), a hydrogen storage cylinder group (7), and a mixing and temperature-controlled tank (2) sequentially located on the main pipeline (15). The cold box (1) and the main pipeline control valve (23) are connected in parallel via a low-temperature hydrogen inflow pipeline (11) and a low-temperature hydrogen outflow pipeline (12) so that the cold box (1) can obtain and store cold energy from the liquid hydrogen released from the liquid hydrogen storage tank (4); a cold storage control valve (21) is provided on the low-temperature hydrogen inflow pipeline (11). The cold box (1) is also connected in parallel to the main pipeline between the hydrogen storage cylinder group (7) and the hydrogen dispenser (3) via a high-temperature hydrogen inflow pipeline (13) and a high-temperature hydrogen outflow pipeline (14). A bypass control valve (22) is provided on the high-temperature hydrogen inflow pipeline (13). A diversion connector is provided between the high-temperature hydrogen inflow pipeline (13) and the main pipeline for diverting the hydrogen released from the hydrogen storage cylinder group (7). The cold box (1) releases cold energy to cool the diverted hydrogen. The mixing and temperature-regulating tank (2) is located at the connection between the high-temperature hydrogen outflow pipeline (14) and the main pipeline for mixing the undiverted hydrogen with the cooled hydrogen to be delivered to the hydrogen dispenser (3) for external output. Control methods include: Cold energy acquisition: When the temperature inside the cold box (1) is higher than the set low temperature, the cold storage control valve (21) is opened. Low temperature hydrogen flows into the cold box (1) through the low temperature hydrogen inflow pipe (11) and exchanges heat with the refrigerant. Then it flows out of the cold box (1) through the low temperature hydrogen outflow pipe (12). The refrigerant obtains cold energy and stores it until the temperature inside the cold box (1) reaches the set low temperature of the cold box. Then the cold storage control valve (21) is closed and the low temperature hydrogen stops flowing into the cold box (1). Pre-cooling refueling: When there is a need for hydrogen refueling, the bypass control valve (22) is opened to allow the hydrogen in the main pipeline to be diverted through the split connector. Part of it flows into the cold box (1) and is cooled by the refrigerant to obtain cold hydrogen. The other part is mixed with the cold hydrogen in the mixing and temperature matching tank (2) to obtain hydrogen that meets the temperature required for refueling pre-cooling, and is output from the hydrogen refueling machine (3). The required pre-cooling temperature for the filling process is -40℃; The liquid hydrogen refueling station also includes a controller. During the pre-cooling refueling process, when there is a need for hydrogen refueling, the controller adjusts the flow rate of hydrogen in the main pipeline and the diversion ratio of the diversion connector according to the required hydrogen refueling rate, the pre-cooling temperature of the hydrogen being refueled, the room temperature, and the real-time temperature inside the cold box. The control method further includes: Ambient temperature storage: Open the main pipeline control valve (23) to allow the low-temperature hydrogen in the liquid hydrogen storage tank (4) to flow through the finned vaporizer (52) and be converted into gaseous hydrogen, which is then stored in the hydrogen storage cylinder group (7); Real-time control: During the hydrogen refueling process, the controller dynamically adjusts the hydrogen splitting ratio at the splitting connector in the hydrogen storage cylinder group (7) according to the real-time temperature in the cold box (1), so that the temperature after mixing and temperature adjustment reaches the pre-cooling temperature required for hydrogen refueling.

2. The control method according to claim 1, characterized in that, A compressor (6) is also provided between the finned vaporizer (52) and the hydrogen storage cylinder group (7).

3. The control method according to claim 1, characterized in that, The finned gasifier (52) is an aluminum finned sleeve gasifier.

4. The control method according to claim 1, characterized in that, The liquid hydrogen refueling station also includes a tube vaporizer (51), which is located between the liquid hydrogen storage tank (4) and the finned vaporizer (52).

5. The control method according to claim 1, characterized in that, The outlet of the liquid hydrogen storage tank (4) is also connected to a liquid hydrogen booster pump (8).

6. The control method according to claim 1, characterized in that, The refrigerant used in the cold box (1) is either solid or liquid.

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