Liquid hydrogen storage equipment for fuel cell

Abstract

The utility model relates to the technical field of pressure containers, in particular to liquid hydrogen storage equipment for a fuel cell, which comprises a liquid hydrogen bottle and a pipeline assembly, the liquid hydrogen bottle comprises an outer container and an inner container, the front end of the inner container is fixedly connected with the outer container, and the rear end of the inner container is movably connected with the outer container. The pipeline assembly comprises a filling pipe, a liquid outlet pipe, a gas phase pipe, a self-pressurization pipe, a replacement pipe and a diffusion pipe. According to the liquid hydrogen storage equipment for the fuel cell disclosed by the utility model, the pipeline assembly is optimally designed, so that the safety of liquid hydrogen in the injection, temporary storage and use states is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of pressure vessels, in particular to a liquid hydrogen hydrogen storage device for fuel cells. Background Technique

[0002] Liquid hydrogen is currently the most efficient and convenient hydrogen storage method among solid-state hydrogen storage, liquid hydrogen storage, and gaseous hydrogen storage. Moreover, the liquid hydrogen hydrogen supply system has good integration, and the volume-weight ratio can be as high as more than 12%, showing great potential in the hydrogen supply system of fuel cell heavy trucks.

[0003] Due to the low temperature of liquid hydrogen (-253°C), in addition to hydrogen safety during use, potential safety hazards brought by the use environment should also be considered, such as the generation of "liquefied air" and "oxygen-rich layer", especially the two-phase flow generated by convective heat exchange with air during filling.

[0004] The volume density of liquid hydrogen is relatively low compared to other fuels. Under the same conditions of 1 atmosphere, the density of liquid hydrogen is only 1 / 6 of that of LNG, and the latent heat of vaporization of its saturated liquid is not much different from that of LNG. Therefore, to reach the usage conditions of LNG cylinders, the heat insulation performance of its storage container needs to be increased by 6 times; and because liquid hydrogen exists in two quantum states of "ortho-hydrogen" and "para-hydrogen", when the temperature drops and hydrogen liquefies, "ortho-hydrogen" will spontaneously convert to "para-hydrogen" and release heat, causing a large amount of the stored liquid hydrogen to vaporize. Therefore, liquid hydrogen hydrogen storage cylinders must have higher heat insulation performance than traditional cryogenic cylinders.

[0005] The liquid hydrogen hydrogen storage system should also meet the hydrogen consumption requirements (3 - 8 g / s) of fuel cell heavy trucks, the cruising range should be greater than 800 Km, and the working pressure of the liquid hydrogen cylinder should be less than the supercritical pressure of liquid hydrogen and be able to meet the required pressure of the fuel cell stack. Therefore, precise control of its transmission pressure is required.

[0006] Therefore, how to achieve the above objectives has become an urgent problem to be studied and solved. Content of the Utility Model

[0007] To achieve the above objectives, the utility model provides a liquid hydrogen hydrogen storage device for fuel cells, which optimizes the design of the pipeline assembly to ensure safety during liquid hydrogen filling, temporary storage, and use.

[0008] To achieve the above objectives, the utility model provides the following technical solution: A liquid hydrogen hydrogen storage device for fuel cells, comprising a liquid hydrogen cylinder and a pipeline assembly;

[0009] The liquid hydrogen cylinder includes an outer cylinder and an inner cylinder. The front end of the inner cylinder is fixedly connected to the outer cylinder, the rear end of the inner cylinder is movably connected to the outer cylinder, and a liquid hydrogen cylinder vacuum pumping port is provided on the front side of the outer cylinder;

[0010] The pipeline assembly includes a filling pipe, a liquid outlet pipe, a gas phase pipe, a self-pressurizing pipe, a replacement pipe, and a blow-off pipe;

[0011] The filling pipe is sequentially provided with a filling port, a first stop valve, and a check valve from front to back in the liquid hydrogen flow direction, and the tail end of the filling pipe extends into the gas phase space at the upper part of the liquid hydrogen bottle;

[0012] One end of the liquid outlet pipe is located in the liquid phase space at the lower part of the liquid hydrogen bottle. The liquid outlet pipe is sequentially connected in series with a second stop valve, an overcurrent valve, and a water bath vaporizer from front to back in the liquid hydrogen flow direction. The water bath vaporizer exchanges heat with the coolant of the hydrogen fuel cell, and the liquid hydrogen is vaporized into hydrogen. The vaporized hydrogen enters the buffer tank and then is transported to the fuel cell stack. A temperature sensor for detecting the temperature of hydrogen is provided on the liquid outlet pipe;

[0013] One end of the gas phase pipe is located in the gas phase space at the upper part of the liquid hydrogen bottle. The other end of the gas phase pipe is provided with an economizer pipe. The end of the economizer pipe far from the gas phase pipe is connected to the liquid outlet pipe, and an economizer regulating valve is connected in series on the economizer pipe;

[0014] One end of the self-pressurizing pipe is located in the liquid phase space at the lower part of the liquid hydrogen bottle. The other end of the self-pressurizing pipe is connected to the gas phase pipe, and a pressure regulating valve and an air-cooled vaporizer are connected in series on the self-pressurizing pipe;

[0015] One end of the replacement pipe is connected to the filling pipe. The connection position of the replacement pipe and the filling pipe is between the filling port and the first stop valve. The other end of the replacement pipe is connected to the blow-off pipe, and a replacement valve is connected in series on the replacement pipe.

[0016] Further, the outer side of the inner tank is coated with a heat insulation layer, and the heat insulation layer is located in the evacuated cavity.

[0017] Further, both the filling pipe and the liquid outlet pipe are composed of an inner pipe and an outer pipe located outside the inner pipe. Both ends of the outer pipe are hermetically connected to the inner pipe. A pipe body evacuation port is provided on the outer pipe, and the air between the inner pipe and the outer pipe is evacuated by an external device. An adsorbent 28 is arranged in the evacuated cavity between the outer pipe and the inner pipe.

[0018] Further, a first safety pipe is connected to the filling pipe in communication. The end of the first safety pipe far from the filling pipe is connected to the blow-off pipe, and a first safety valve is connected in series on the first safety pipe.

[0019] Further, a second safety pipe is connected to the gas phase pipe in communication. The end of the second safety pipe far from the gas phase pipe is connected to the blow-off pipe, and a second safety valve and a pressure gauge are connected in series on the second safety pipe. A pressure sensor is provided on the second safety pipe.

[0020] Further, the upper end of the blow-off pipe is connected to the blow-off pipe network, and a drain valve is provided at the lower end of the blow-off pipe.

[0021] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0022] 1. Since there is heat leakage when the medium in the low-temperature pressure vessel is stored, the liquid hydrogen bottle of the present utility model adopts a double-layer structure design. On the one hand, it meets the strength requirements of the on-vehicle liquid hydrogen bottle, and on the other hand, it can reduce the heat leaking into the liquid hydrogen bottle through the pipeline from the outside, such as heat conduction, heat convection and heat radiation.

[0023] 2. Since the boiling point of hydrogen is lower than the boiling point and melting point of oxygen, at the temperature of liquid hydrogen, oxygen will form solid oxygen particles on the surface of the pipeline and then absorb heat and vaporize to form an oxygen-gathered air mass. In an oxygen-rich environment, the ignition point and autoignition point of substances will decrease, and combustion is extremely likely to occur. Hydrogen is an inflammable and explosive medium. In an oxygen-rich environment, the accident risks of both vehicles and hydrogen refueling stations will increase greatly. Therefore, both the filling pipe and the liquid outlet pipe in the present utility model adopt a double-layer structure, which can effectively solve the problem of the oxygen-rich layer.

[0024] In summary, the liquid hydrogen storage device for fuel cells disclosed by the utility model not only meets the requirements of liquid hydrogen filling, cleaning, pressurization, exhaust and liquid use, but also adopts a double-wall high-vacuum insulation design for the filling pipe and the liquid outlet pipe to avoid the generation of two-phase flow during liquid hydrogen filling and the harmful phenomena such as "liquefied air" and "oxygen-rich layer" during the use of liquid hydrogen; through reasonable system design and layout, the on-vehicle liquid hydrogen bottle is realized to be safe, easy to use and mass-produced. Description of the Drawings

[0025] Figure 1 It is a partial cross-sectional view of the left side view of the liquid hydrogen storage device for fuel cells in the embodiment;

[0026] Figure 2 It is a partial cross-sectional view of the left side view of the liquid hydrogen storage device for fuel cells in the embodiment;

[0027] Figure 3 It is a structural schematic diagram of the pipeline assembly in the embodiment.

[0028] Main Component Symbol Explanation:

[0029] 11 - Outer tank, 12 - Inner tank, 13 - Connecting shaft, 14 - Sleeve, 15 - Liquid hydrogen bottle vacuum pumping port, 16 - Insulation layer;

[0030] 21 - Filling pipe, 211 - Filling port, 212 - First stop valve, 213 - Check valve, 214 - First safety pipe, 215 - First safety valve;

[0031] 22 - Liquid outlet pipe, 221 - Second stop valve, 222 - Overflow valve, 223 - Water bath vaporizer, 224 - Temperature sensor;

[0032] 23 - Gas phase pipe, 231 - Economy pipe, 232 - Economy regulating valve, 233 - Second safety pipe, 234 - Second safety valve, 235 - Pressure gauge, 236 - Pressure sensor;

[0033] 24 - Self - pressurizing pipe, 241 - Pressurizing regulating valve;

[0034] 25 - Displacement pipe, 251 - Displacement valve;

[0035] 26 - Bleed pipe, 261 - Drain valve.

[0036] 27 - Pipe body vacuum port;

[0037] 28 - Adsorbent. Specific embodiments

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0039] Please refer to Figures 1 to 3 , the present invention provides a technical solution: A liquid hydrogen storage device for a fuel cell, including a liquid hydrogen bottle and a pipeline assembly;

[0040] The liquid hydrogen bottle includes an outer tank 11 and an inner tank 12. The front end of the inner tank 12 is fixedly connected to the outer tank 11, and the rear end of the inner tank 12 is movably connected to the outer tank 11. Specifically: Connecting shafts 13 are respectively arranged at the front and rear ends of the inner tank 12, and bushings 14 are respectively arranged at the front and rear ends of the outer tank 11. The connecting shaft 13 at the front end of the inner tank 12 is hermetically welded and fixed to the bushing 14 at the front end of the outer tank 11, and the connecting shaft 13 at the rear end of the inner tank 12 is inserted and matched with the bushing 14 at the rear end of the outer tank 11. A liquid hydrogen bottle vacuum port 15 is arranged on the front side of the outer tank 11, and the space between the outer tank 11 and the inner tank 12 is evacuated by an external vacuum device. In this embodiment, between the connecting shaft 13 and the inner tank 12, and between the connecting shaft 13 and the bushing 14, a support structure that can reduce the heat leakage of the system by extending the heat transfer path can be adopted. Specifically, reference can be made to the utility model patent with the authorization number of CN218671590 and the invention creation name of an ultra - low temperature vacuum adiabatic pressure vessel with a double - detour support structure applied by our company recently.

[0041] As a preferred solution of this embodiment, the outer side of the inner tank 12 is covered with a heat insulation layer 16. The heat insulation layer 16 is located in the evacuated cavity. In this embodiment, the heat insulation layer 16 is composed of aluminum foil and fiberglass paper, achieving high thermal resistance between layers and effectively reducing thermal radiation.

[0042] The pipeline assembly includes a filling pipe 21, a liquid outlet pipe 22, a gas phase pipe 23, a self-pressurizing pipe 24, a replacement pipe 25, and a relief pipe 26.

[0043] The filling pipe 21 is sequentially provided with a filling port 211, a first stop valve 212, and a check valve 213 from front to back in the liquid hydrogen flow direction. The tail end of the filling pipe 21 extends into the gas phase space at the upper part of the liquid hydrogen cylinder.

[0044] As a preferred solution of this embodiment, a first safety pipe 214 is connected to the filling pipe 21. One end of the first safety pipe 214 away from the filling pipe 21 is connected to the relief pipe 26, and a first safety valve 215 is connected in series on the first safety pipe 214.

[0045] One end of the liquid outlet pipe 22 is located in the liquid phase space at the lower part of the liquid hydrogen cylinder. The liquid outlet pipe 22 is sequentially connected in series with a second stop valve 221, an overcurrent valve 222, and a water bath vaporizer 223 from front to back in the liquid hydrogen flow direction. The water bath vaporizer 223 exchanges heat with the coolant of the hydrogen fuel cell, and the liquid hydrogen is vaporized into hydrogen. The vaporized hydrogen enters the buffer tank and then is transported to the fuel cell stack. A temperature sensor 224 for detecting the hydrogen temperature is provided on the liquid outlet pipe 22.

[0046] As a preferred solution of this embodiment, both the filling pipe 21 and the liquid outlet pipe 22 are composed of an inner pipe and an outer pipe located outside the inner pipe. The two ends of the outer pipe are hermetically connected to the inner pipe. A pipe body evacuation port 27 is provided on the outer pipe, and the air between the inner pipe and the outer pipe is evacuated by an external device. An adsorbent 28 is provided in the evacuated cavity between the outer pipe and the inner pipe.

[0047] One end of the gas phase pipe 23 is located in the gas phase space at the upper part of the liquid hydrogen cylinder. The other end of the gas phase pipe 23 is provided with an economy pipe 231. One end of the economy pipe 231 away from the gas phase pipe 23 is connected to the liquid outlet pipe 22, and an economy regulating valve 232 is connected in series on the economy pipe 231. When the pressure in the liquid hydrogen cylinder is higher than the pressure set by the economy regulating valve 232, the economy regulating valve 232 opens, and the gas in the liquid hydrogen cylinder is preferentially used to supply hydrogen to the fuel cell stack, preventing the waste of gas discharge caused by too high pressure in the liquid hydrogen cylinder and realizing the economic function.

[0048] As a preferred solution of this embodiment, a second safety pipe 233 is connected to the gas phase pipe 23. One end of the second safety pipe 233 away from the gas phase pipe 23 is connected to the blow-off pipe 26. A second safety valve 234 and a pressure gauge 235 are connected in series on the second safety pipe 233, and a pressure sensor 236 is arranged on the second safety pipe 233.

[0049] One end of the self-pressurizing pipe 24 is located in the liquid phase space at the lower part of the liquid hydrogen cylinder. The other end of the self-pressurizing pipe 24 is connected to the gas phase pipe 23. A pressure regulating valve 241 and an air-cooled vaporizer are connected in series on the self-pressurizing pipe 24. When the pressure in the liquid hydrogen cylinder is lower than the set pressure of the pressure regulating valve 241, the pressure regulating valve 241 opens, and the liquid hydrogen in the liquid hydrogen cylinder flows out. After being vaporized by the air-cooled vaporizer, the gas flows through the gas phase pipe 23 and then returns to the gas phase space at the top of the liquid hydrogen cylinder, so as to increase the pressure in the liquid hydrogen cylinder and realize the function of pressurizing the liquid hydrogen cylinder.

[0050] One end of the replacement pipe 25 is connected to the filling pipe 21. The connection position of the replacement pipe 25 and the filling pipe 21 is between the filling port 211 and the first stop valve 212. The other end of the replacement pipe 25 is connected to the blow-off pipe 26. A replacement valve 251 is connected in series on the replacement pipe 25. Before filling and refueling, because the temperature of the liquid hydrogen is too low, it is necessary to use hydrogen to purge and replace the dust and air at the nozzle of the filling pipe 21 until the nitrogen in hydrogen, oxygen in hydrogen, water dew point, etc. reach safe conditions before the liquid hydrogen can be filled and refueled.

[0051] The upper end of the blow-off pipe 26 is connected to the blow-off pipe network, and a drain valve 261 is arranged at the lower end of the blow-off pipe 26.

[0052] The liquid hydrogen storage and hydrogen storage device for fuel cells disclosed by the present utility model has the following working principle:

[0053] Filling: When the vehicle enters the hydrogen refueling station to fill liquid hydrogen, first use the hydrogen refueling gun to purge the dust and air between the filling port 211 and the first stop valve 212. The replacement medium is hydrogen, and the exhausted gas is transported to the blow-off pipe network by the blow-off pipe 26 for unified collection. Then, the hydrogen refueling gun transports the liquid hydrogen to the inner tank 12 through the filling pipe 21;

[0054] Liquid discharging: The liquid hydrogen flows through the second stop valve 221 and the flow control valve 222 to the water bath vaporizer 223, and exchanges heat with the coolant of the hydrogen fuel cell in the water bath vaporizer 223. The liquid hydrogen is vaporized into hydrogen gas, and the vaporized hydrogen gas enters the buffer tank and then is transported to the fuel cell stack;

[0055] When the pressure in the liquid hydrogen cylinder is higher than the set pressure of the economic regulating valve 232, the economic regulating valve 232 opens, and the gas in the liquid hydrogen cylinder is preferentially used to supply hydrogen to the fuel cell stack through the liquid discharging pipe.

[0056] When the pressure in the liquid hydrogen cylinder is lower than the set pressure of the booster pressure regulating valve 241, the booster pressure regulating valve 241 opens, and the liquid hydrogen in the liquid hydrogen cylinder flows out. After being vaporized by the air-cooled vaporizer, the gas flows through the gas phase pipe 23 and then returns to the gas phase space at the top of the liquid hydrogen cylinder, causing the pressure in the liquid hydrogen cylinder to rise.

[0057] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Liquid hydrogen storage equipment for fuel cells, characterized in that: It includes a liquid hydrogen cylinder and a pipeline assembly; The liquid hydrogen cylinder includes an outer cylinder and an inner cylinder. The front end of the inner cylinder is fixedly connected to the outer cylinder, and the rear end of the inner cylinder is movably connected to the outer cylinder. A liquid hydrogen cylinder vacuum pumping port is provided on the front side of the outer cylinder; The pipeline assembly includes a filling pipe, a liquid outlet pipe, a gas phase pipe, a self-pressurizing pipe, a replacement pipe, and a relief pipe; The filling pipe is sequentially provided with a filling port, a first stop valve, and a check valve from front to back in the liquid hydrogen flow direction. The tail end of the filling pipe extends into the gas phase space at the upper part of the liquid hydrogen cylinder; One end of the liquid outlet pipe is located in the liquid phase space at the lower part of the liquid hydrogen cylinder. The liquid outlet pipe is sequentially connected in series with a second stop valve, an overcurrent valve, and a water bath vaporizer from front to back in the liquid hydrogen flow direction. The water bath vaporizer exchanges heat with the coolant of the hydrogen fuel cell, and the liquid hydrogen is vaporized into hydrogen. The vaporized hydrogen enters the buffer tank and then is transported to the fuel cell stack. A temperature sensor for detecting the temperature of hydrogen is provided on the liquid outlet pipe; One end of the gas phase pipe is located in the gas phase space at the upper part of the liquid hydrogen cylinder. The other end of the gas phase pipe is provided with an economy pipe. The end of the economy pipe far from the gas phase pipe is connected to the liquid outlet pipe, and an economy regulating valve is connected in series on the economy pipe; One end of the self-pressurizing pipe is located in the liquid phase space at the lower part of the liquid hydrogen cylinder. The other end of the self-pressurizing pipe is connected to the gas phase pipe, and a pressure regulating valve and an air temperature vaporizer are connected in series on the self-pressurizing pipe; One end of the replacement pipe is connected to the filling pipe. The connection position of the replacement pipe and the filling pipe is between the filling port and the first stop valve. The other end of the replacement pipe is connected to the relief pipe, and a replacement valve is connected in series on the replacement pipe; 2. The liquid hydrogen hydrogen storage device for a fuel cell according to claim 1, characterized in that: An adiabatic layer is coated on the outside of the inner cylinder, and the adiabatic layer is located in the vacuum pumping cavity; 3. The liquid hydrogen hydrogen storage device for a fuel cell according to claim 1, characterized in that: The filling pipe and the liquid outlet pipe are both composed of an inner pipe and an outer pipe located outside the inner pipe. The two ends of the outer pipe are hermetically connected to the inner pipe. A pipe body vacuum pumping port is provided on the outer pipe. The air between the inner pipe and the outer pipe is pumped out by external equipment, and an adsorbent 28 is provided in the vacuum cavity between the outer pipe and the inner pipe; 4. The liquid hydrogen storage device for a fuel cell according to claim 1, characterized in that: A first safety pipe is communicated with the filling pipe. The end of the first safety pipe far from the filling pipe is connected to the relief pipe, and a first safety valve is connected in series on the first safety pipe; 5. The liquid hydrogen storage device for a fuel cell according to claim 1, characterized in that: A second safety pipe is communicated with the gas phase pipe. The end of the second safety pipe far from the gas phase pipe is connected to the relief pipe, and a second safety valve and a pressure gauge are connected in series on the second safety pipe. A pressure sensor is provided on the second safety pipe; 6. The liquid hydrogen hydrogen storage device for a fuel cell according to claim 1, characterized in that: The upper end of the relief pipe is connected to the relief pipe network, and a drain valve is provided at the lower end of the relief pipe.

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