Liquid hydrogen pressurized subcooled filling system

Abstract

This utility model discloses a liquid hydrogen pressurization and subcooling refueling system, comprising: a liquid hydrogen storage tank, the liquid phase outlet of which is connected to the inlet of a liquid hydrogen pump pool via an outlet pipe; a submersible plunger pump immersed in the liquid hydrogen pump pool, the outlet of which is connected to the inlet of a liquid hydrogen refueling machine via a hydrogen delivery pipeline; the hydrogen delivery pipeline consists of a first hydrogen delivery pipe, a second hydrogen delivery pipe, and a liquid-helium dual-function heat exchanger; the medium inlet of the liquid-helium dual-function heat exchanger is connected to a liquid helium source via a pipeline; the BOG outlet of the liquid hydrogen pump pool is connected to the gas phase port of the liquid hydrogen storage tank via a return gas pipe; one end of the discharge pipe is connected to the return gas pipe; a nitrogen source is connected to the outlet pipe via a nitrogen pipe; a hydrogen source is connected to the outlet pipe via a hydrogen pipe; and the submersible plunger pump is driven by a hydraulic drive unit located in a non-explosion-proof area. The aforementioned liquid hydrogen pressurization and subcooling refueling system features high safety, low loss, and high refueling accuracy and efficiency.

Description

Technical Field

[0001] This utility model relates to the field of liquid hydrogen refueling equipment, specifically to a liquid hydrogen pressurization and subcooling refueling system. Background Technology

[0002] Traditional liquid hydrogen refueling systems present several problems during storage and refueling: 1) The liquid hydrogen pumps used in these systems are mostly directly driven by electric motors, posing significant safety hazards. 2) During pressurization and refueling, liquid hydrogen in conventional systems easily evaporates due to heat absorption, resulting in substantial evaporation losses. This affects refueling accuracy and efficiency, leading to resource waste and increased operating costs. 3) Traditional systems often directly discharge BOG (boil-off gas) generated by natural evaporation, wasting energy and impacting the environment. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a liquid hydrogen pressurization and subcooling refueling system with high safety, low loss, high refueling accuracy and efficiency.

[0004] To solve the above problems, the technical solution adopted by this utility model is as follows: a liquid hydrogen pressurization and subcooling filling system, comprising: a liquid hydrogen storage tank, the liquid phase outlet of the liquid hydrogen storage tank being connected to the inlet of a liquid hydrogen pump pool via an outlet pipe, a submersible plunger pump installed and submerged in the liquid hydrogen pump pool, the outlet of the submersible plunger pump being connected to the inlet of a liquid hydrogen dispenser via a hydrogen delivery pipeline, and the liquid hydrogen dispenser adding hydrogen to the liquid hydrogen cylinder via a hydrogen dispensing gun. The system is characterized in that: the hydrogen delivery pipeline consists of a first hydrogen delivery pipeline, a second hydrogen delivery pipeline, and a liquid-helium dual-function heat exchanger; the inlet of the first hydrogen delivery pipeline is connected to the outlet of the submersible plunger pump; the outlet of the first hydrogen delivery pipeline is connected to the inlet of the first medium of the liquid-helium dual-function heat exchanger; and the outlet of the first medium is connected to the inlet of the second hydrogen delivery pipeline. The outlet of the second hydrogen pipeline is connected to the liquid hydrogen refueling machine. The second medium inlet of the liquid helium dual-function heat exchanger is connected to the gas phase port of the liquid hydrogen storage tank through a pipeline with a pneumatic regulating valve. The second medium outlet is connected to the liquid outlet pipe through a reuse pipe. The third medium inlet of the liquid helium dual-function heat exchanger is connected to the liquid helium source through a pipeline. The third medium outlet is used to discharge helium. The BOG outlet of the liquid hydrogen pump pool is connected to the gas phase port of the liquid hydrogen storage tank through a return gas pipe. One end of the discharge pipe is connected to the return gas pipe. The nitrogen source is connected to the liquid outlet pipe through a nitrogen pipe. The hydrogen source is connected to the liquid outlet pipe through a hydrogen pipe. The submersible plunger pump is driven by a hydraulic drive unit located in a non-explosion-proof area. The hydraulic drive unit includes a hydraulic motor, a hydraulic pump, and a control valve assembly.

[0005] Furthermore, the aforementioned liquid hydrogen pressurization and subcooling filling system also includes a liquid nitrogen cylinder. The outlet of the liquid nitrogen cylinder is connected to the liquid outlet pipe via a liquid nitrogen pipe, and a pneumatic regulating valve and a check valve are connected in series on the liquid nitrogen pipe.

[0006] Furthermore, in the aforementioned liquid hydrogen pressurization and subcooling refueling system, the following components are connected in series: a pneumatic regulating valve, a safety valve, a temperature sensor, and a pressure sensor on the liquid outlet pipe; a pneumatic regulating valve and a check valve on the nitrogen pipe; a pneumatic regulating valve and a check valve on the hydrogen pipe; a temperature sensor and a pneumatic regulating valve on the return pipe; a pneumatic regulating valve and a pressure sensor on the discharge pipe; a pneumatic regulating valve, a safety valve, a temperature sensor, and a pressure sensor on the first hydrogen delivery pipe; a pneumatic regulating valve, a temperature sensor, and a pressure sensor on the second hydrogen delivery pipe; a pneumatic regulating valve, a safety valve, a temperature sensor, and a pressure sensor on the reuse pipe; a pneumatic regulating valve and a temperature sensor on the pipe connected to the third medium inlet of the liquid helium dual-function heat exchanger; and a pneumatic regulating valve on the pipe connected to the third medium outlet of the liquid helium dual-function heat exchanger. A controller is also provided, and each pneumatic regulating valve is controlled by the controller. Each temperature sensor and each pressure sensor are communicatively connected to the controller.

[0007] Furthermore, in the aforementioned liquid hydrogen pressurization and subcooling refueling system, the liquid hydrogen pump tank has a three-layer structure: the inner layer is a stainless steel layer containing liquid hydrogen, the middle layer is a vacuum insulation layer, and the outer layer is a high-strength protective layer. The inner layer is fixedly connected to the outer layer through insulation components, and the top of the liquid hydrogen pump tank is equipped with a sealing cap.

[0008] Furthermore, the aforementioned liquid hydrogen pressurization and subcooling refueling system also includes a BOG recovery connector for connecting to the gas phase outlet of the liquid hydrogen cylinder, and the second medium inlet of the liquid helium dual-function heat exchanger is connected to the BOG recovery connector via a pipe with a pneumatic regulating valve.

[0009] The advantages of this invention are as follows: The liquid hydrogen pressurization and subcooling refueling system uses liquid nitrogen to precool the entire system, effectively avoiding the high losses caused by the large temperature difference during direct precooling of liquid hydrogen. Liquid nitrogen is stable, and even if leaks occur in sealing components during precooling, it will not cause high-risk accidents such as explosions or fires. This measure greatly improves the safety and economy of the entire system operation. A hydraulic drive unit drives the submersible plunger pump, and the hydraulic drive unit is installed in a non-explosion-proof area, completely eliminating the risk of hydrogen explosion caused by electrical sparks, fundamentally improving safety. The hydraulic drive unit does not require explosion-proof certification, reducing overall costs. Maintenance personnel can directly repair the hydraulic unit in non-explosion-proof areas, reducing downtime and operational risks. Through a liquid-helium dual-function heat exchanger and intelligent control system, the pressurized liquid hydrogen is subcooled and BOG is liquefied, improving refueling accuracy and efficiency. All BOG that was originally directly emitted is recovered, liquefied, and reused, significantly reducing greenhouse gas emissions and powerfully promoting environmental protection. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating the working principle of the liquid hydrogen pressurization and subcooling refueling system. Detailed Implementation

[0011] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0012] like Figure 1As shown, the liquid hydrogen pressurization and subcooling refueling system includes: a liquid hydrogen storage tank 1, the liquid phase outlet of which is connected to the inlet of a liquid hydrogen pump pool 3 via an outlet pipe 2; a submersible plunger pump 4 installed and submerged in the liquid hydrogen pump pool 3, the outlet of which is connected to the inlet of a liquid hydrogen refueling machine 5 via a hydrogen delivery pipeline; liquid hydrogen in the liquid hydrogen storage tank 1 flows into the liquid hydrogen pump pool 3; the submersible plunger pump 4 pumps the liquid hydrogen in the liquid hydrogen pump pool 3 to the liquid hydrogen refueling machine 5; the liquid hydrogen refueling machine 5 adds hydrogen to the liquid hydrogen cylinder 6 via a hydrogen refueling gun; and a hydrogen delivery pipeline consisting of a first hydrogen delivery pipe 7, a second hydrogen delivery pipe 9, and a liquid-helium dual-function heat exchanger 8. The inlet of the first hydrogen delivery pipe 7 is connected to the outlet of the submersible plunger pump 4. The outlet of the liquid helium dual-function heat exchanger 8 is connected to the inlet of medium one, the outlet of medium one is connected to the inlet of the second hydrogen pipeline 9, and the outlet of the second hydrogen pipeline 9 is connected to the liquid hydrogen refueling machine 5. The inlet of medium two of the liquid helium dual-function heat exchanger 8 is connected to the gas phase port of the liquid hydrogen storage tank 1 through a pipeline with a pneumatic regulating valve 15. The outlet of medium two is connected to the liquid outlet pipe 2 through a return pipe 13. The inlet of medium three of the liquid helium dual-function heat exchanger 8 is connected to the liquid helium source 12 through a pipeline. The outlet of medium three is used to discharge helium. The BOG outlet of the liquid hydrogen pump pool 3 is connected to the gas phase port of the liquid hydrogen storage tank 1 through a return gas pipe 10. One end of the discharge pipe 11 is connected to the return gas pipe 10. The nitrogen source 21 is connected to the liquid outlet pipe 2 through a nitrogen pipe 22. Connected, hydrogen source 23 is connected to outlet pipe 2 via hydrogen pipe 24. Submersible plunger pump 4 is driven by hydraulic drive unit 18, which is located in a non-explosion-proof area. Hydraulic drive unit 18 includes a hydraulic motor, hydraulic pump, and control valve group. Pneumatic regulating valve 15, safety valve 25, temperature sensor 16, and pressure sensor 17 are connected in series on outlet pipe 2. Pneumatic regulating valve 15 and check valve 26 are connected in series on nitrogen pipe 22. Pneumatic regulating valve 15 and check valve 26 are connected in series on hydrogen pipe 24. Temperature sensor 16 and pneumatic regulating valve 15 are connected in series on return pipe 10. Pneumatic regulating valve 15 and pressure sensor 17 are connected in series on discharge pipe 11. The first hydrogen delivery pipe 7 is connected in series with... The system includes a pneumatic regulating valve 15, a safety valve 25, a temperature sensor 16, and a pressure sensor 17. These components are connected in series on the second hydrogen delivery pipe 9, the return pipe 13, and the pipeline connecting to the medium inlet of the liquid helium dual-function heat exchanger 8. A pneumatic regulating valve 15 and a temperature sensor 16 are also connected in series on the pipeline connecting to the medium outlet of the liquid helium dual-function heat exchanger 8. A controller is also provided, controlling each pneumatic regulating valve. All temperature and pressure sensors are communicatively connected to the controller. A liquid nitrogen cylinder 19 is also provided, with its outlet connected to the liquid outlet pipe via a liquid nitrogen pipe 20. A pneumatic regulating valve 15 and a check valve 26 are connected in series on the liquid nitrogen pipe 20.

[0013] The liquid hydrogen pump tank 3 has a three-layer structure: an inner stainless steel layer for holding liquid hydrogen, a middle vacuum insulation layer, and an outer high-strength protective layer. The inner layer is fixedly connected to the outer layer by insulation components, and the top of the liquid hydrogen pump tank 3 is equipped with a sealing cap. This design allows the liquid hydrogen pump tank 3 to have better insulation performance.

[0014] A BOG recovery connector 14 is also provided for connecting to the gas phase outlet of liquid hydrogen cylinder 6. The medium inlet of the liquid helium dual-function heat exchanger 8 is connected to the BOG recovery connector 14 via a pipe equipped with a pneumatic regulating valve. When the BOG in liquid hydrogen cylinder 6 increases and causes excessive pressure, the BOG in liquid hydrogen cylinder 6 can be introduced into the liquid helium dual-function heat exchanger 8 for liquefaction and recovery by connecting the BOG recovery connector 14 to the gas phase outlet.

[0015] All liquid hydrogen refueling systems typically undergo comprehensive pre-cooling with liquid hydrogen before refueling to ensure the system meets startup requirements. This process consumes a significant amount of liquid hydrogen. Furthermore, liquid hydrogen possesses extremely low temperatures (-253°C) and is highly flammable and explosive. During pre-cooling, the liquid hydrogen exchanges heat with the ambient-temperature pipelines. This significant temperature difference can trigger thermal stress, potentially altering pipeline material properties, damaging the structure, and creating safety risks. Simultaneously, the initial ambient-temperature connections, after pre-cooling with liquid hydrogen, are prone to gaps at seals due to thermal expansion and contraction, leading to leaks. Once leaked, liquid hydrogen rapidly vaporizes, forming a flammable mixture. Upon contact with open flames, static electricity, or other ignition sources, this mixture can ignite violently or even explode, posing a significant safety hazard.

[0016] The aforementioned liquid hydrogen pressurized subcooled refueling system employs staged precooling: During the precooling of the entire refueling system, the valve is first opened to allow liquid nitrogen from the liquid nitrogen cylinder to initiate initial precooling. Once the system temperature drops to a specific value, the liquid nitrogen is discharged. Then, nitrogen is used first, followed by hydrogen for purging and replacement until the hydrogen replacement meets the acceptable standards, after which hydrogen precooling is initiated.

[0017] This method of pre-cooling with liquid nitrogen significantly reduces the temperature difference during the subsequent actual heat exchange with liquid hydrogen. This reduced temperature difference effectively minimizes hydrogen loss due to intense heat exchange. Furthermore, even if leaks occur in some sealing components during the liquid nitrogen pre-cooling stage, only liquid nitrogen will leak. This allows staff to proactively identify and eliminate potential leaks, thus strengthening the safety barrier for subsequent hydrogen pre-cooling.

[0018] Traditional liquid hydrogen pumps are directly driven by an electric motor, and the motor unit is integrated with the pump body in an explosion-proof area. This poses a risk of hydrogen explosion caused by electrical sparks, resulting in insufficient drive safety. Direct motor drive requires explosion-proof design, which increases cost and system complexity. In addition, the heat transfer generated by direct motor drive increases the evaporation loss of liquid hydrogen.

[0019] The liquid hydrogen pressurization and subcooling filling system abandons the traditional direct motor drive and adopts a hydraulically driven submersible plunger pump 4. By placing the hydraulic drive unit in a non-explosion-proof area, the risk of liquid hydrogen explosion caused by electric sparks generated by the motor drive is fundamentally eliminated, greatly improving the inherent safety of the system. At the same time, it reduces the heat transfer from the motor operation to the liquid hydrogen, effectively reducing evaporation losses during the pressurization process.

[0020] Maintaining liquid hydrogen in a subcooled state is difficult. Conventional liquid hydrogen refueling systems rely on the insulation performance of the storage tank itself to maintain the low temperature. However, after pressurization, the temperature of liquid hydrogen inevitably rises, making it prone to vaporization during transportation, which affects the metering accuracy and refueling efficiency.

[0021] The liquid hydrogen pressurization and subcooling injection system features a liquid-helium dual-function heat exchanger 8 at the outlet of the submersible plunger pump 4. Pressure sensors 17 and 16 monitor the temperature and pressure of the pressurized liquid hydrogen and the BOG in real time, feeding the data back to the controller. Based on this feedback data, the controller dynamically adjusts the opening of the corresponding pneumatic regulating valve 15 to precisely control the liquid helium injection volume. When the pressurized liquid hydrogen temperature is high or the BOG is difficult to liquefy, the opening of the corresponding pneumatic regulating valve 15 increases, increasing the liquid helium injection volume, enhancing the cooling effect, and bringing the liquid hydrogen to a subcooled state while simultaneously liquefying the BOG. ​​Conversely, when the temperature and pressure are within a suitable range, the opening of the corresponding pneumatic regulating valve 15 decreases, reducing the liquid helium injection volume and avoiding resource waste.

[0022] By using liquid nitrogen precooling, placing the hydraulic drive unit in a non-explosion-proof area, utilizing liquid helium cold energy, and employing intelligent control, the system systematically solves the safety, energy efficiency, and integration challenges in the field of liquid hydrogen refueling, making it suitable for large-scale hydrogen energy infrastructure.

Claims

1. Liquid hydrogen pressurization and subcooling refueling system, including: A liquid hydrogen storage tank, the liquid phase outlet of which is connected to the inlet of a liquid hydrogen pump pool via an outlet pipe, a submersible plunger pump installed and submerged in the liquid hydrogen pump pool, the outlet of which is connected to the inlet of a liquid hydrogen dispenser via a hydrogen delivery pipeline, the liquid hydrogen dispenser dispensing hydrogen to the liquid hydrogen cylinder via a dispensing nozzle, characterized in that: the hydrogen delivery pipeline consists of a first hydrogen delivery pipeline, a second hydrogen delivery pipeline, and a liquid-helium dual-function heat exchanger; the inlet of the first hydrogen delivery pipeline is connected to the outlet of the submersible plunger pump, the outlet of the first hydrogen delivery pipeline is connected to the inlet of medium one of the liquid-helium dual-function heat exchanger, the outlet of medium one is connected to the inlet of the second hydrogen delivery pipeline, and the outlet of the second hydrogen delivery pipeline is connected to the liquid hydrogen dispenser; the liquid-helium dual-function heat exchanger... The medium two inlet of the functional heat exchanger is connected to the gas phase port of the liquid hydrogen storage tank through a pipe with a pneumatic regulating valve, and the medium two outlet is connected to the liquid outlet pipe through a reuse pipe. The medium three inlet of the liquid helium dual-function heat exchanger is connected to the liquid helium source through a pipe, and the medium three outlet is used to discharge helium. The BOG outlet of the liquid hydrogen pump pool is connected to the gas phase port of the liquid hydrogen storage tank through a return gas pipe, and one end of the discharge pipe is connected to the return gas pipe. The nitrogen source is connected to the liquid outlet pipe through a nitrogen pipe, and the hydrogen source is connected to the liquid outlet pipe through a hydrogen pipe. The submersible plunger pump is driven by a hydraulic drive unit, which is located in a non-explosion-proof area. The hydraulic drive unit includes a hydraulic motor, a hydraulic pump, and a control valve group.

2. The liquid hydrogen pressurization and subcooling refueling system according to claim 1, characterized in that: It is also equipped with a liquid nitrogen cylinder, the outlet of which is connected to the liquid outlet pipe via a liquid nitrogen pipe. A pneumatic regulating valve and a check valve are connected in series on the liquid nitrogen pipe.

3. The liquid hydrogen pressurization and subcooling refueling system according to claim 1 or 2, characterized in that: A pneumatic regulating valve, a safety valve, a temperature sensor, and a pressure sensor are connected in series on the liquid outlet pipe; a pneumatic regulating valve and a check valve are connected in series on the nitrogen pipe; a pneumatic regulating valve and a check valve are connected in series on the hydrogen pipe; a temperature sensor and a pneumatic regulating valve are connected in series on the return pipe; a pneumatic regulating valve and a pressure sensor are connected in series on the discharge pipe; a pneumatic regulating valve, a safety valve, a temperature sensor, and a pressure sensor are connected in series on the first hydrogen supply pipe; a pneumatic regulating valve, a temperature sensor, and a pressure sensor are connected in series on the second hydrogen supply pipe; a pneumatic regulating valve, a safety valve, a temperature sensor, and a pressure sensor are connected in series on the reuse pipe; a pneumatic regulating valve and a temperature sensor are connected in series on the pipe connected to the third medium inlet of the liquid-helium dual-function heat exchanger; a pneumatic regulating valve is connected in series on the pipe connected to the third medium outlet of the liquid-helium dual-function heat exchanger; a controller is also provided, and each pneumatic regulating valve is controlled by the controller. Each temperature sensor and each pressure sensor are communicatively connected to the controller.

4. The liquid hydrogen pressurization and subcooling refueling system according to claim 1 or 2, characterized in that: The liquid hydrogen pump tank has a three-layer structure: the inner layer is a stainless steel layer for holding liquid hydrogen, the middle layer is a vacuum insulation layer, and the outer layer is a high-strength protective layer. The inner layer is fixedly connected to the outer layer by insulation components, and the top of the liquid hydrogen pump tank is equipped with a sealing cover.

5. The liquid hydrogen pressurization and subcooling refueling system according to claim 1 or 2, characterized in that: It is also equipped with a BOG recovery connector for connecting the gas phase outlet of the liquid hydrogen cylinder. The medium inlet of the liquid helium dual-function heat exchanger is connected to the BOG recovery connector through a pipe with a pneumatic regulating valve.

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