Active Liquid Hydrogen On-Vehicle Storage System and Means of Transportation

Abstract

The present invention belongs to the field of green new energy technologies, and discloses an active on-vehicle liquid hydrogen storage system. The active on-vehicle liquid hydrogen storage system includes a liquid hydrogen storage tank, a heat insulation unit, and a condensation unit. The liquid hydrogen storage tank is used for storing liquid hydrogen, and a first evaporation space is left inside the liquid hydrogen storage tank. The heat insulation unit is disposed outside the liquid hydrogen storage tank to block the heat in the environment from entering the liquid hydrogen storage tank. The condensation unit includes a liquefaction cover and a refrigeration system. The cold heads of both the liquefaction cover and the refrigeration system are arranged inside the liquid hydrogen storage tank. The cold heads are used to cool the liquefaction cover, so that the gaseous hydrogen evaporated in the liquid hydrogen storage tank can be condensed into liquid hydrogen on the liquefaction cover. The active on-vehicle liquid hydrogen storage system achieves the effect of combining passive heat insulation and active heat insulation, prolongs the storage time of liquid hydrogen, and reduces the loss rate of liquid hydrogen caused by evaporation.

Description

Technical Field

[0001] The present invention relates to the technical field of green new energy, and particularly to an active on-vehicle liquid hydrogen storage system and a transportation vehicle. Background Art

[0002] As a green clean energy, the use and transportation of hydrogen have attracted more and more attention and efforts have been made for in-depth development and research. Since the energy density per unit volume of hydrogen is very low (only 0.084 kg / m 3 under normal pressure), and at the same pressure, the energy density of liquid hydrogen is 840 times that of hydrogen. Therefore, the use and transportation of liquid hydrogen are the research focuses of hydrogen energy utilization.

[0003] The ambient temperature for daily use of liquid hydrogen by people is usually around 300 K (27 degrees Celsius), while the self-temperature of liquid hydrogen is around 20 K. There is a huge temperature difference between the ambient temperature for using liquid hydrogen and the self-temperature of liquid hydrogen. This means that without effective measures or equipment support, the liquid hydrogen in the storage tank will evaporate quickly. If the tightness of the storage tank is poor, the evaporated hydrogen will be quickly lost. If the tightness of the storage tank is very good, the pressure inside the storage tank will rapidly increase with the evaporation of liquid hydrogen, making the storage tank face risks such as explosion and even combustion.

[0004] In the prior art, in order to keep the liquid hydrogen in the storage tank in a liquid state, the method adopted is to set a heat insulation protection layer outside the storage tank to block the heat in the environment from entering the storage tank. The heat insulation effect of the above passive heat insulation method is very limited because the huge temperature difference (about 280 K) between the inside and outside of the storage tank always exists, which makes it very difficult to completely block the heat radiation. Therefore, how to achieve active heat insulation of the storage tank is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] An object of the present invention is to provide an active on-vehicle liquid hydrogen storage system, which can achieve the combined effect of passive heat insulation and active heat insulation of the liquid hydrogen storage tank.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] The active on-vehicle liquid hydrogen storage system includes:

[0008] A liquid hydrogen storage tank for storing liquid hydrogen, and a first evaporation space is left inside the liquid hydrogen storage tank;

[0009] A heat insulation unit surrounding the outside of the liquid hydrogen storage tank, and the heat insulation unit can block the heat in the environment from entering the liquid hydrogen storage tank;

[0010] The condensation unit, which includes a liquefaction cover and a refrigeration system. The liquefaction cover is disposed inside the liquid hydrogen storage tank and above the liquid hydrogen. The refrigeration system includes a cold head, which is disposed inside the liquid hydrogen storage tank and is used to cool the liquefaction cover, enabling the gaseous hydrogen evaporated inside the liquid hydrogen storage tank to condense into liquid hydrogen on the liquefaction cover.

[0011] Optionally, the active on-vehicle liquid hydrogen storage system further includes a safety treatment unit, which includes a reaction tank and a liquid nitrogen storage tank. The reaction tank is provided with an exhaust port. The liquid nitrogen storage tank is used to store liquid nitrogen, and a second evaporation space is left inside the liquid nitrogen storage tank. The tops of the liquid hydrogen storage tank and the liquid nitrogen storage tank are both connected to the reaction tank. The gaseous hydrogen evaporated inside the liquid hydrogen storage tank and the gaseous nitrogen evaporated inside the liquid nitrogen storage tank can react in the reaction tank to generate ammonia gas, and the ammonia gas can be discharged from the exhaust port of the reaction tank.

[0012] Optionally, the safety treatment unit further includes a safety pipeline and a safety valve. The top of the liquid hydrogen storage tank is connected to the reaction tank through the safety pipeline, and the safety valve is disposed on the safety pipeline. When the air pressure value inside the liquid hydrogen storage tank reaches a preset value, the safety valve opens.

[0013] Optionally, the heat insulation unit includes a vacuum outer shell, which surrounds the outside of the liquid hydrogen storage tank, and a vacuum cavity is formed between the vacuum outer shell and the liquid hydrogen storage tank.

[0014] Optionally, the heat insulation unit further includes a buffer member, which has elasticity, and the vacuum outer shell and the liquid hydrogen storage tank are connected through the buffer member.

[0015] Optionally, the heat insulation unit further includes a heat radiation protection screen, which surrounds the outside of the liquid hydrogen storage tank and is disposed inside the vacuum cavity.

[0016] Optionally, the refrigeration system further includes a compressor, a radiator, and a throttling and pressure-reducing element. The compressor and the radiator are both disposed outside the liquid hydrogen storage tank. The compressor, the radiator, the throttling and pressure-reducing element, and the cold head are sequentially connected through a connecting pipe, and a working medium flows through the connecting pipe.

[0017] Optionally, the radiator is a cooling water tank, which is used to absorb the heat of the working medium discharged by the compressor.

[0018] Another object of the present invention is to provide a transportation vehicle, which not only achieves the effect of zero emissions, but also has a relatively stable and reliable energy supply, making the transportation vehicle have a high safety.

[0019] To achieve this object, the present invention adopts the following technical solutions:

[0020] The transportation vehicle includes a power system and the above-mentioned active on-vehicle liquid hydrogen storage system. The liquid hydrogen storage tank is connected to the power system, and the liquid hydrogen storage tank is used to supply liquid hydrogen to the power system.

[0021] Beneficial effects:

[0022] In the active liquid hydrogen vehicle-mounted storage system provided by the present invention, a first evaporation space for the evaporation of liquid hydrogen is left in the liquid hydrogen storage tank, and a liquefaction cover and the cold head of a refrigeration system are arranged in the liquid hydrogen storage tank. The liquefaction cover is located above the liquid hydrogen, and the cold head is used to cool the liquefaction cover. At the same time, a heat insulation unit is arranged around the outside of the liquid hydrogen storage tank. The heat insulation unit is used to block the heat in the environment from entering the liquid hydrogen storage tank, so that a part of the heat in the environment is blocked outside the liquid hydrogen storage tank by the heat insulation unit, and another part of the heat enters the liquid hydrogen storage tank to evaporate the liquid hydrogen into gaseous hydrogen. The gaseous hydrogen flows upward in the liquid hydrogen storage tank and condenses into liquid hydrogen on the low-temperature liquefaction cover and then flows back into the liquid hydrogen. Thus, the effect of combining passive heat insulation and active heat insulation of the liquid hydrogen storage tank is achieved. The setting of active heat insulation absorbs the heat that cannot be blocked by passive heat insulation, effectively prolongs the storage time of liquid hydrogen, and reduces the loss rate of liquid hydrogen caused by evaporation.

[0023] The transportation vehicle provided by the present invention adopts the above-mentioned active liquid hydrogen vehicle-mounted storage system. The liquid hydrogen storage tank provides liquid hydrogen to the power system of the transportation vehicle as a power source, achieving the zero-emission effect of the transportation vehicle. Moreover, the reliability and stability of the liquid hydrogen storage tank for storing liquid hydrogen are relatively high, thereby improving the reliability and stability of the energy supply of the transportation vehicle. At the same time, the safety of the transportation vehicle using hydrogen energy as a power source is also improved. Description of the drawings

[0024] Figure 1 It is a schematic structural diagram of a vehicle adopting an active liquid hydrogen vehicle-mounted storage system provided in this embodiment.

[0025] In the figure:

[0026] 10, vehicle frame;

[0027] 100, liquid hydrogen storage tank; 110, liquid hydrogen output pipe; 210, liquefaction cover; 211, hem; 221, cold head; 222, compressor; 310, reaction tank; 311, exhaust port; 320, liquid nitrogen storage tank; 321, liquid nitrogen replenishment port; 322, gaseous nitrogen pressure relief port; 330, safety pipeline; 331, safety valve; 410, vacuum outer shell; 421, first vacuum chamber; 422, second vacuum chamber; 430, heat radiation shielding screen; 441, first buffer member; 442, second buffer member; 450, MLI film; 500, high-pressure seal; 510, vacuum suction valve; 520, vacuum pressure release valve; 530, liquid injection pipe; 540, liquid level indicator. Detailed implementation manners

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention are shown in the drawings, rather than all the structures.

[0029] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0031] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0032] This embodiment provides an active on-vehicle liquid hydrogen storage system, which can achieve the combined effect of passive heat insulation and active heat insulation of the liquid hydrogen storage tank.

[0033] Specifically, as Figure 1As shown, the active on-vehicle liquid hydrogen storage system includes a liquid hydrogen storage tank 100, a heat insulation unit, and a condensation unit. The liquid hydrogen storage tank 100 is used to store liquid hydrogen, and a first evaporation space for the evaporation of liquid hydrogen is left inside the liquid hydrogen storage tank 100. The heat insulation unit is disposed around the outside of the liquid hydrogen storage tank 100, and the heat insulation unit can block the heat in the environment from entering the liquid hydrogen storage tank 100. The condensation unit includes a liquefaction cover 210 and a refrigeration system. The liquefaction cover 210 is arranged inside the liquid hydrogen storage tank 100 and above the liquid hydrogen. The refrigeration system includes a cold head 221. The cold head 221 is arranged inside the liquid hydrogen storage tank 100, and the cold head 221 is used to cool the liquefaction cover 210 so that the gaseous hydrogen evaporated inside the liquid hydrogen storage tank 100 can be condensed into liquid hydrogen on the liquefaction cover 210.

[0034] For this active on-vehicle liquid hydrogen storage system, a first evaporation space for the evaporation of liquid hydrogen is left inside the liquid hydrogen storage tank 100, and the liquefaction cover 210 and the cold head 221 of the refrigeration system are arranged inside the liquid hydrogen storage tank 100. The liquefaction cover 210 is located above the liquid hydrogen, and the cold head 221 is used to cool the liquefaction cover 210. At the same time, a heat insulation unit is disposed around the outside of the liquid hydrogen storage tank 100, and the heat insulation unit is used to block the heat in the environment from entering the liquid hydrogen storage tank 100, so that a part of the heat in the environment is blocked outside the liquid hydrogen storage tank 100 by the heat insulation unit, and another part of the heat enters the liquid hydrogen storage tank 100 to evaporate the liquid hydrogen into gaseous hydrogen. The gaseous hydrogen flows upward inside the liquid hydrogen storage tank 100 and is condensed into liquid hydrogen on the low-temperature liquefaction cover 210 and then flows back into the liquid hydrogen. Thus, the effect of combining passive heat insulation (i.e., the heat insulation unit) and active heat insulation (i.e., the condensation unit) of the liquid hydrogen storage tank 100 is achieved. The setting of active heat insulation absorbs the heat that the passive heat insulation fails to block, effectively extends the storage time of liquid hydrogen inside the liquid hydrogen storage tank 100, and reduces the loss rate of liquid hydrogen due to evaporation.

[0035] Furthermore, the above liquefaction cover 210 is made of a heat-conducting material, so that the overall temperature of the liquefaction cover 210 is relatively uniform, and the gaseous hydrogen can be quickly condensed at different positions of the liquefaction cover 210.

[0036] Preferably, the cold head 221 is in contact with the liquefaction cover 210 to improve the cooling effect of the cold head 221 on the liquefaction cover 210, and further improve the condensation rate of the gaseous hydrogen on the liquefaction cover 210.

[0037] Optionally, the cross-sectional area of the liquefaction cover 210 is equal to the cross-sectional area of the liquid hydrogen storage tank 100, so that the gaseous hydrogen at different positions inside the liquefaction cover 210 can contact and condense with the liquefaction cover 210, further improving the condensation effect of the liquefaction cover 210 on the gaseous hydrogen.

[0038] Optionally, as Figure 1As shown, the edge of the liquefaction cover 210 is provided with a hem 211, and the angle between the hem 211 and the liquefaction cover 210 is a right angle or an obtuse angle. Exemplarily, the angle between the hem 211 and the liquefaction cover 210 can be 90°, 100°, 135°, etc., so as to facilitate the condensed liquid hydrogen to flow back along the hem 211 into the liquid hydrogen pool (i.e., the liquid hydrogen at the lower part of the liquid hydrogen storage tank 100).

[0039] Optionally, as Figure 1 shown, the refrigeration system further includes a compressor 222, a radiator, and a throttling and pressure-reducing element (the radiator and the throttling and pressure-reducing element are not shown in the figure). The compressor 222 and the radiator are both arranged outside the liquid hydrogen storage tank 100. The compressor 222, the radiator, the throttling and pressure-reducing element, and the cold head 221 are sequentially connected through a connecting pipe. A working medium flows in the connecting pipe. The working medium in the cold head 221 absorbs the heat of the liquefaction cover 210 to achieve the effect of cooling the liquefaction cover 210. Further, the compressor 222 can be a helium compressor 222, and then the above-mentioned working medium should be helium. Of course, in other embodiments, the compressor 222 can also be other types of compressors. At this time, the above-mentioned working medium should be a refrigeration medium matching the compressor, as long as the cold head 221 can achieve the effect of cooling the liquefaction cover 210.

[0040] Further, the radiator is a cooling water tank. The cooling water tank is used to absorb the heat of the working medium discharged by the compressor 222. Compared with air, the cooling water has a higher heat transfer coefficient. Therefore, using the cooling water in the cooling water tank to absorb the heat of the working medium discharged by the compressor 222 can increase the heat transfer amount of the working medium in the connecting pipe, and then improve the refrigeration efficiency of the refrigeration system and the heat absorption efficiency of the cold head 221, achieving the effect of increasing the condensation rate of gaseous hydrogen on the liquefaction cover 210.

[0041] Optionally, as Figure 1 shown, the heat insulation unit includes a vacuum outer shell 410. The vacuum outer shell 410 surrounds the outside of the liquid hydrogen storage tank 100, and there is a vacuum cavity between the vacuum outer shell 410 and the liquid hydrogen storage tank 100 to achieve the effect of vacuum heat insulation for the liquid hydrogen storage tank 100.

[0042] Further, as Figure 1 shown, the heat insulation unit further includes a heat radiation protection screen 430. The heat radiation protection screen 430 surrounds the outside of the liquid hydrogen storage tank 100 and is placed in the vacuum cavity. Adding the heat radiation protection screen 430 on the basis of vacuum heat insulation further improves the heat insulation effect on the liquid hydrogen storage tank 100. Preferably, as Figure 1As shown, the above-mentioned vacuum chamber includes a first vacuum chamber 421 and a second vacuum chamber 422. The first vacuum chamber 421 and the second vacuum chamber 422 are respectively located on both sides of the heat radiation shielding screen 430, so as to achieve the effect of arranging two vacuum chambers outside the liquid hydrogen storage tank 100, and further improve the heat insulation effect. Preferably, the temperature of the heat radiation shielding screen 430 is the same as that of the liquid nitrogen storage tank 320.

[0043] Preferably, as Figure 1 shown, the outer wall of the heat radiation shielding screen 430 is wrapped with multiple layers of MLI (multi-layer insulation material) films to further improve the heat insulation effect on the liquid hydrogen storage tank 100. It should be noted that the above MLI film 450 is a thin film composed of a composite of polyimide and a metal material (such as aluminum foil, etc.). Its specific components and preparation process are all relatively mature existing technologies in the art and will not be elaborated here.

[0044] Optionally, since there is a first evaporation space for liquid hydrogen to evaporate in the liquid hydrogen storage tank 100, when the liquid hydrogen storage tank 100 shakes under the action of external factors, surges will occur in the liquid hydrogen in the liquid hydrogen storage tank 100. The surges hitting the inner wall of the liquid hydrogen storage tank 100 will form static electricity. If there is gaseous hydrogen in the first evaporation space, the gaseous hydrogen will explode and burn when it comes into contact with the static electricity. To solve this technical problem, as Figure 1 shown, the heat insulation unit further includes a buffer member. The buffer member has elasticity. The vacuum outer shell 410 and the liquid hydrogen storage tank 100 are connected through the buffer member, thereby realizing the buffering of the shaking of the liquid hydrogen storage tank 100, and further reducing the probability of the formation of surges of liquid hydrogen. Further, the buffer member includes a first buffer member 441 and a second buffer member 442. Both the first buffer member 441 and the second buffer member 442 have elasticity. The two ends of the first buffer member 441 are respectively connected to the liquid hydrogen storage tank 100 and the heat radiation shielding screen 430 to achieve the vibration damping and buffering effect on the liquid hydrogen storage tank 100. The two ends of the second buffer member 442 are respectively connected to the heat radiation shielding screen 430 and the vacuum outer shell 410 to achieve the vibration damping and buffering effect on the heat radiation shielding screen 430. Thus, a double vibration damping and buffering effect on the liquid hydrogen storage tank 100 is realized, greatly reducing the probability of the formation of surges of liquid hydrogen, and further effectively improving the use safety of the active liquid hydrogen storage system. Optionally, the first buffer member 441 and the second buffer member 442 can be elastic elements such as urethane rubber or springs.

[0045] Optionally, as Figure 1As shown, the active on-vehicle liquid hydrogen storage system further includes a safety treatment unit. The safety treatment unit includes a reaction tank 310 and a liquid nitrogen storage tank 320. The reaction tank 310 is provided with an exhaust port 311. The liquid nitrogen storage tank 320 is used to store liquid nitrogen. A second evaporation space for the evaporation of liquid nitrogen is reserved in the liquid nitrogen storage tank 320. The top of the liquid hydrogen storage tank 100 and the top of the liquid nitrogen storage tank 320 are both connected to the reaction tank 310. The gaseous hydrogen evaporated in the liquid hydrogen storage tank 100 and the gaseous nitrogen evaporated in the liquid nitrogen storage tank 320 can react in the reaction tank 310 to generate ammonia gas, and the ammonia gas can be discharged from the reaction tank 310 through the exhaust port 311. When the refrigeration system fails and the cold head 221 cannot cool the liquefaction cover 210, the gaseous hydrogen evaporated in the liquid hydrogen storage tank 100 will not be able to condense on the liquefaction cover 210, which will cause the pressure in the liquid hydrogen storage tank 100 to continuously increase. If the high-pressure gaseous hydrogen in the liquid hydrogen storage tank 100 is not discharged in time, the pressure in the liquid hydrogen storage tank 100 will exceed its safety pressure, and then dangers such as the explosion or combustion of the liquid hydrogen storage tank 100 will occur. If the high-pressure gaseous hydrogen in the liquid hydrogen storage tank 100 is directly discharged into the external environment, the discharged gaseous hydrogen is extremely likely to cause explosions and other dangers at the ambient temperature. To solve this technical problem, in this embodiment, the top of the liquid hydrogen storage tank 100 and the top of the liquid nitrogen storage tank 320 are both connected to the reaction tank 310. When the pressure in the liquid hydrogen storage tank 100 rises to the safety pressure value of the liquid hydrogen storage tank 100, the gaseous hydrogen in the liquid hydrogen storage tank 100 enters the reaction tank 310, and moreover, the gaseous nitrogen in the liquid nitrogen storage tank 320 enters the reaction tank 310. The gaseous hydrogen and gaseous nitrogen react in the reaction tank 310 to generate ammonia gas, and then the ammonia gas is discharged from the reaction tank 310 through the exhaust port 311 to achieve the effect of reducing the pressure of the liquid hydrogen storage tank 100, thereby avoiding dangers such as the explosion or even combustion of the liquid hydrogen storage tank 100 when the refrigeration system fails, and also avoiding the danger of explosion when the gaseous hydrogen is directly discharged into the external environment, improving the safety of the active on-vehicle liquid hydrogen storage system. On the other hand, when injecting liquid hydrogen into the liquid hydrogen storage tank 100 for the first time, if liquid hydrogen is directly injected, most of the liquid hydrogen will quickly evaporate. Therefore, before injecting liquid hydrogen for the first time, liquid nitrogen can be first injected into the liquid hydrogen storage tank 100. The liquid nitrogen evaporates and absorbs heat in the liquid hydrogen storage tank 100, causing the temperature of the liquid hydrogen storage tank 100 to drop to about 77 - 80K. After the liquid nitrogen has completely evaporated and been drained, liquid hydrogen is then slowly injected into the liquid hydrogen storage tank 100. Since all the interfaces of the liquid hydrogen storage tank 100 are in a sealed state, there is a certain vapor pressure above the interior of the liquid hydrogen storage tank 100 after the liquid hydrogen injection is completed. In this embodiment, the liquid nitrogen injected into the liquid hydrogen storage tank 100 can be injected from the liquid nitrogen storage tank 320 into the liquid hydrogen storage tank 100, or can be injected from other liquid nitrogen supply sources into the liquid hydrogen storage tank 100.It should be noted that gaseous hydrogen and gaseous nitrogen need to react to produce ammonia under the action of a catalyst. The reaction chamber 310 should be equipped with conditions for the reaction of gaseous hydrogen and gaseous nitrogen to produce ammonia. The specific type of catalyst is common prior art in this field and will not be elaborated here. As long as it can enable gaseous hydrogen and gaseous nitrogen to react to produce ammonia in the reaction chamber 310.

[0046] Furthermore, as Figure 1 shown, the safety treatment unit further includes a safety pipeline 330 and a safety valve 331. The top of the liquid hydrogen storage tank 100 is connected to the reaction chamber 310 through the safety pipeline 330. The safety valve 331 is arranged on the safety pipeline 330. When the air pressure value in the liquid hydrogen storage tank 100 reaches a preset value (i.e., the above-mentioned safety pressure value), the safety valve 331 opens, enabling the gaseous hydrogen in the liquid hydrogen storage tank 100 to enter the reaction chamber 310 through the safety pipeline 330. Optionally, the safety valve 331 can be a pressure relief valve, and the above preset value is the set pressure value of the pressure relief valve. When the pressure value in the safety pipeline 330 reaches the set pressure value of the pressure relief valve, the pressure relief valve opens; or, the safety valve 331 can also be a first solenoid valve. A pressure sensor is arranged in the liquid hydrogen storage tank 100. When the pressure value detected by the pressure sensor is greater than or equal to the preset value, the controller controls the first solenoid valve to open.

[0047] Optionally, as Figure 1 shown, the liquid nitrogen storage tank 320 is provided with a liquid nitrogen replenishment port 321 for injecting liquid nitrogen into the liquid nitrogen storage tank 320. After the liquid nitrogen in the liquid nitrogen storage tank 320 evaporates into gaseous nitrogen, the pressure in the liquid nitrogen storage tank 320 increases. Therefore, a gaseous nitrogen pressure relief port 322 needs to be opened on the liquid nitrogen storage tank 320. When the pressure in the liquid nitrogen storage tank 320 rises to a certain value, the gaseous nitrogen can be discharged through the gaseous nitrogen pressure relief port 322 to ensure the safety of the liquid nitrogen storage tank 320. It can be understood that the liquid nitrogen replenishment port 321 and the gaseous nitrogen pressure relief port 322 can be the same communication port or two different communication ports, depending on the actual application requirements.

[0048] Optionally, the safety treatment unit further includes a nozzle. The nozzle is connected to the cooling water tank and is arranged facing the exhaust port 311. When ammonia is discharged from the exhaust port 311, the cooling water is sprayed from the nozzle towards the exhaust port 311 to dilute and reduce the impact of ammonia on the environment. Furthermore, a second solenoid valve and a water pump are arranged on the pipeline connecting the nozzle and the cooling water tank. When the first solenoid valve opens, the controller controls the second solenoid valve to open and controls the water pump to start to achieve the effect of the nozzle spraying cooling water.

[0049] It should be noted that the selection of the refrigeration capacity of the above refrigeration system can be based on past low-temperature experience and thermal finite element analysis and calculation to obtain the total heat leakage of the liquid hydrogen storage tank 100 and the required cooling capacity, and then determine the size and quantity of the refrigeration capacity of the refrigeration system, so that the cooling capacity provided by the refrigeration system is balanced with the heat leakage of the liquid hydrogen storage tank 100. In this embodiment, as Figure 1 shown, two cold heads 221 are selected to cool the liquefaction cover 210. And, two high-pressure sealing ports 500 are provided on the vacuum outer shell 410 for the two cold heads 221 to extend into the liquid hydrogen storage tank 100, while ensuring the sealing performance of the liquid hydrogen storage tank 100.

[0050] Furthermore, as Figure 1 shown, a vacuum suction valve 510 is provided on the high-pressure sealing port 500 to achieve vacuum pumping of the first vacuum chamber 421 and the second vacuum chamber 422. A vacuum pressure relief valve 520 is also provided on the high-pressure sealing port 500 to ensure that when the pressure and temperature in the first vacuum chamber 421, the second vacuum chamber 422, and the liquid hydrogen storage tank 100 change, the first vacuum chamber 421 and the second vacuum chamber 422 will not be affected by excessive positive and negative pressures, thereby improving the overall safety of the active liquid hydrogen vehicle-mounted storage system. A liquid injection pipe 530 for injecting liquid hydrogen into the liquid hydrogen storage tank 100 is also provided on the high-pressure sealing port 500, and a liquid level indicator 540 for monitoring the liquid level of liquid hydrogen in the liquid hydrogen storage tank 100 is also provided. Further, the liquid hydrogen storage tank 100 is also connected to a liquid hydrogen output pipe 110 to transport the liquid hydrogen in the liquid hydrogen storage tank 100 to the liquid hydrogen usage end. It should be noted that the above-mentioned vacuum suction valve 510, vacuum pressure relief valve 520, liquid injection pipe 530, and liquid level indicator 540 are all hermetically connected to the high-pressure sealing port 500, and the liquid hydrogen output pipe 110 is hermetically connected to the liquid hydrogen storage tank 100 to ensure the sealing performance of the liquid hydrogen storage tank 100. Each pipeline extending into the interior of the liquid hydrogen storage tank 100, such as the liquid hydrogen output pipe 110 and the liquid injection pipe 530, etc., is made of materials with poor thermal conductivity such as stainless steel and other materials to reduce the heat leakage of the liquid hydrogen storage tank 100.

[0051] The active liquid hydrogen vehicle-mounted storage system provided in this embodiment realizes the combination of passive heat insulation and active heat insulation of the liquid hydrogen storage tank 100, balances the cooling capacity provided by the refrigeration system with the heat leakage of the liquid hydrogen storage tank 100, effectively extends the storage time of liquid hydrogen, and reduces the loss rate of liquid hydrogen due to evaporation.

[0052] This embodiment also provides a transportation tool, which includes a power system and the above-mentioned active liquid hydrogen vehicle-mounted storage system. The liquid hydrogen storage tank 100 is connected to the power system, and the liquid hydrogen storage tank 100 is used to provide liquid hydrogen to the power system as fuel for the power system. Exemplarily, the above-mentioned transportation tool can be a vehicle or a ship, etc. In this embodiment, taking a vehicle as an example, asFigure 1 As shown, the above-mentioned power system and the active on-vehicle liquid hydrogen storage system are both installed on the vehicle frame 10.

[0053] It should be noted that the capacity of the liquid hydrogen storage tank 100 in the active on-vehicle liquid hydrogen storage system can be determined according to the power demand of the transportation vehicle. In this embodiment, an 800L liquid hydrogen storage tank 100 is adopted to meet the power demand of the vehicle. In other embodiments, liquid hydrogen storage tanks 100 with other capacities can also be adopted to meet the power demands of other vehicles, ships or other transportation vehicles.

[0054] The transportation vehicle adopts the above-mentioned active on-vehicle liquid hydrogen storage system. The liquid hydrogen storage tank 100 provides liquid hydrogen as a power source for the power system of the transportation vehicle, achieving a zero-emission effect for the transportation vehicle. Moreover, in the active on-vehicle liquid hydrogen storage system, the cooling capacity provided by the refrigeration system is balanced with the heat leakage of the liquid hydrogen storage tank 100, so that there is almost no additional loss of liquid hydrogen during transportation and use, well solving the problem of maintaining liquid hydrogen in a liquid state during long-term turnover, transportation and use of liquid hydrogen, and improving the safety of transportation vehicles using liquid hydrogen as a power source.

[0055] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. An active on-vehicle liquid hydrogen storage system, characterized in that, Comprising: A liquid hydrogen storage tank (100) for storing liquid hydrogen, and a first evaporation space is left inside the liquid hydrogen storage tank (100); A heat insulation unit surrounding the outside of the liquid hydrogen storage tank (100), which can block the heat in the environment from entering the liquid hydrogen storage tank (100); A condensation unit including a liquefaction cover (210) and a refrigeration system. The liquefaction cover (210) is arranged inside the liquid hydrogen storage tank (100) and above the liquid hydrogen. The refrigeration system includes a cold head (221) arranged inside the liquid hydrogen storage tank (100). The cold head (221) is used to cool the liquefaction cover (210) so that the gaseous hydrogen evaporated in the liquid hydrogen storage tank (100) can be condensed into liquid hydrogen on the liquefaction cover (210); The active on-vehicle liquid hydrogen storage system further includes a safety treatment unit, which includes a reaction tank (310) and a liquid nitrogen storage tank (320). The reaction tank (310) is provided with an exhaust port (311). The liquid nitrogen storage tank (320) is used to store liquid nitrogen, and a second evaporation space is left inside the liquid nitrogen storage tank (320). The tops of the liquid hydrogen storage tank (100) and the liquid nitrogen storage tank (320) are both connected to the reaction tank (310). The gaseous hydrogen evaporated in the liquid hydrogen storage tank (100) and the gaseous nitrogen evaporated in the liquid nitrogen storage tank (320) can react in the reaction tank (310) to generate ammonia gas, and the ammonia gas can be discharged from the reaction tank (310) through the exhaust port (311).

2. The active on-vehicle liquid hydrogen storage system according to claim 1, wherein The safety treatment unit further includes a safety pipeline (330) and a safety valve (331). The top of the liquid hydrogen storage tank (100) is connected to the reaction tank (310) through the safety pipeline (330). The safety valve (331) is arranged on the safety pipeline (330). When the air pressure value in the liquid hydrogen storage tank (100) reaches a preset value, the safety valve (331) opens.

3. The active on-vehicle liquid hydrogen storage system according to any one of claims 1-2, characterized in that The heat insulation unit includes a vacuum outer shell (410) surrounding the outside of the liquid hydrogen storage tank (100), and a vacuum cavity is formed between the vacuum outer shell (410) and the liquid hydrogen storage tank (100).

4. The active on-vehicle liquid hydrogen storage system according to claim 3, wherein The heat insulation unit further includes a buffer member with elasticity, and the vacuum outer shell (410) is connected to the liquid hydrogen storage tank (100) through the buffer member.

5. The active on-vehicle liquid hydrogen storage system according to claim 3, characterized in that, The heat insulation unit further includes a heat radiation protection screen (430) surrounding the outside of the liquid hydrogen storage tank (100) and placed in the vacuum cavity.

6. The active on-vehicle liquid hydrogen storage system according to any one of claims 1-2, characterized in that, The refrigeration system further includes a compressor (222), a radiator and a throttling and pressure reducing element. The compressor (222) and the radiator are both arranged outside the liquid hydrogen storage tank (100). The compressor (222), the radiator, the throttling and pressure reducing element and the cold head (221) are sequentially connected through a connecting pipe, and a working medium flows in the connecting pipe.

7. The active on-vehicle liquid hydrogen storage system according to claim 6, wherein, The radiator is a cooling water tank, and the cooling water tank is used to absorb the heat of the working medium discharged by the compressor (222).

8. A means of transportation, characterized in that, It includes a power system and the active on-vehicle liquid hydrogen storage system according to any one of claims 1-7. The liquid hydrogen storage tank (100) is communicated with the power system, and the liquid hydrogen storage tank (100) is used to supply the liquid hydrogen to the power system.

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