A vehicle-mounted liquid hydrogen fuel cell cold energy utilization system

Abstract

The present invention provides a vehicle-mounted liquid hydrogen fuel cell cold energy utilization system, which includes a fuel cell stack, a hydrogen supply subsystem, an air conditioning subsystem, a fuel cell cooling subsystem, and a power battery subsystem. The hydrogen supply subsystem is connected to the fuel cell stack and is used to convert liquid hydrogen into gaseous hydrogen and then input it into the fuel cell stack. The air conditioning subsystem is connected to the hydrogen supply subsystem and is used to obtain the cold energy released during the conversion of liquid hydrogen into gaseous hydrogen. The fuel cell cooling subsystem is connected to the hydrogen supply subsystem and cools or preheats the fuel cell stack by obtaining the cold energy of the gaseous hydrogen. The power battery subsystem is connected to the hydrogen supply subsystem and is used for power generation by recovering the preheat generated by the hydrogen supply subsystem. The present invention makes full use of the cold energy during the vaporization of liquid hydrogen, greatly improving the utilization rate of liquid hydrogen as an automotive energy source and realizing the recycling of energy. It can also make full use of the waste heat of lithium batteries and motors, realizing the interaction of cold energy and system heat.

Description

Technical Field

[0001] The present invention relates to the field of liquid hydrogen fuel cells or new energy vehicles, and particularly to a vehicle-mounted liquid hydrogen fuel cell cold energy utilization system. Background Art

[0002] Excessive carbon emissions leading to global warming have become a problem faced by all mankind today. With the development of China's economic society, the number of motor vehicles in possession has increased rapidly. According to statistics, as of the end of March 2022, the number of motor vehicles in the country reached 402 million, of which 307 million were cars. The exhaust emissions of motor vehicles seriously pollute the environment and affect people's physical health.

[0003] With the development of hydrogen energy, hydrogen energy has become an excellent choice to replace fossil fuels. Liquid hydrogen has advantages such as high energy density, high purity, and suitability for long-distance transportation. The density of liquid hydrogen at -253°C is 70.85 kg / m3, which is about 800 times the density of gaseous hydrogen under standard conditions and about 1.7 times that of high-pressure hydrogen at 70 MPa and 20°C. This makes liquid hydrogen the best hydrogen supply form for hydrogen fuel cells.

[0004] In a liquid hydrogen fuel cell vehicle, before liquid hydrogen enters the fuel cell, it needs to be vaporized by a vaporizer and converted into gaseous hydrogen to participate in the reaction. A large amount of cold energy is generated during the vaporization process of liquid hydrogen, and through the heat exchange between the outer shell of the vaporizer and the air, cold energy is wasted. In the existing technology, although there have been a large number of studies on the utilization of the cold energy of liquid hydrogen vaporization in hydrogen fuel cell vehicles, such as using the heat of liquid hydrogen vaporization and temperature rise, and using a coolant to utilize the cold energy for vehicle air conditioning refrigeration, fuel cell cooling, etc. This cold energy management strategy is simple and easy to implement, but it is not comprehensive enough. Since a large amount of heat that can be utilized is generated by the battery and the engine in the whole vehicle, this heat has not been well utilized, and heat exchange between components cannot be achieved, and the energy is not efficiently utilized, so the energy utilization rate of the system will inevitably decrease.

[0005] In addition, in the existing technology, using the cold energy of liquid hydrogen for vehicle air conditioning refrigeration and fuel cell cooling is the most common method, and it cannot ensure the full utilization of cold energy during the process. Therefore, research on heat interaction and efficient cold energy utilization of the vehicle-mounted liquid hydrogen fuel cell cold energy utilization system needs to be carried out urgently. Summary of the Invention

[0006] Aiming at the deficiencies in the existing technology, the present invention provides a vehicle-mounted liquid hydrogen fuel cell cold energy utilization system, which utilizes a large amount of cold energy released by the vaporization of liquid hydrogen at -253°C through a heat exchanger and a vaporizer, and applies it to vehicle air conditioning refrigeration, fuel cell cooling, and cold energy power generation, so as to greatly improve the utilization rate of liquid hydrogen as an automotive energy source, reduce energy consumption, and increase the cruising range. It can also ensure no pollution and zero emissions during vehicle driving, and realize the recycling of energy.

[0007] The present invention achieves the above technical objectives through the following technical means.

[0008] A vehicle-mounted liquid hydrogen fuel cell cold energy utilization system includes a fuel cell stack, a hydrogen supply subsystem, an air conditioning subsystem, a fuel cell cooling subsystem, and a power battery subsystem.

[0009] The hydrogen supply subsystem is connected to the fuel cell stack and is used to convert liquid hydrogen into gaseous hydrogen and then input it into the fuel cell stack; the air conditioning subsystem is connected to the hydrogen supply subsystem and is used to obtain the cold energy released during the conversion of liquid hydrogen into gaseous hydrogen; the fuel cell cooling subsystem is connected to the hydrogen supply subsystem and cools or preheats the fuel cell stack by obtaining the cold energy of gaseous hydrogen; the power battery subsystem is connected to the hydrogen supply subsystem and is used to generate electricity by recovering the waste heat generated by the hydrogen supply subsystem.

[0010] Further, the hydrogen supply subsystem includes a liquid hydrogen storage tank, a first solenoid valve, a vaporizer, a third solenoid valve, a first heat exchanger, a pump, a pressure regulating valve, a first three-way valve, a second heater, and a second three-way valve; the liquid hydrogen storage tank is sequentially connected to the first solenoid valve, the vaporizer, the third solenoid valve, the first heat exchanger, the pump, the pressure regulating valve, and the first three-way valve. One outlet of the first three-way valve is connected to the second heater, and the other outlet of the first three-way valve is connected to one inlet of the second three-way valve. The second heater is connected to the other inlet of the second three-way valve, and the outlet of the second three-way valve is connected to the fuel cell stack; a first temperature sensor is installed at the outlet of the first heat exchanger. When the temperature detected by the first temperature sensor is greater than or equal to the first set value, the pump outlet is connected to the fuel cell stack through the second three-way valve by controlling the first three-way valve; when the temperature detected by the first temperature sensor is less than the first set value, the pump outlet is connected to the fuel cell stack through the second heater and the second three-way valve by controlling the first three-way valve; the electric energy generated by the fuel cell stack is input into the lithium battery.

[0011] Further, the air conditioning subsystem includes an expansion tank, a second solenoid valve, a water pump, a first compressor, a four-way valve, a first condenser, an evaporator, an expansion throttle valve, and a blower. The cooling water outlet H of the vaporizer is sequentially connected to the expansion tank, the second solenoid valve, the water pump, the first compressor, and the interface d of the four-way valve. The interface c of the four-way valve is sequentially connected to the interface a of the four-way valve through the first condenser and the evaporator; the interface b of the four-way valve is connected to the cooling water outlet E of the vaporizer through the expansion throttle valve.

[0012] Further, when the air conditioning subsystem is in the cooling mode, by controlling the four-way valve, the interface d of the four-way valve is connected to the interface c of the four-way valve, and the interface a of the four-way valve is connected to the interface b of the four-way valve; when the air conditioning subsystem is in the heating mode, by controlling the four-way valve, the interface d of the four-way valve is connected to the interface a of the four-way valve, and the interface c of the four-way valve is connected to the interface b of the four-way valve.

[0013] Further, the fuel cell cooling subsystem includes a first refrigerant tank, a fourth solenoid valve, a first heater, a fifth solenoid valve, a sixth solenoid valve, a radiator, and a refrigerant circulation pump;

[0014] The refrigerant outlet of the first heat exchanger is connected to the first refrigerant tank. The first outlet of the first refrigerant tank is sequentially connected to the sixth solenoid valve, the radiator, and the refrigerant inlet of the fuel cell stack. The second outlet of the first refrigerant tank is sequentially connected to the fifth solenoid valve and the refrigerant inlet of the fuel cell stack. The third outlet of the first refrigerant tank is sequentially connected to the fourth solenoid valve, the first heater, and the refrigerant inlet of the fuel cell stack. The refrigerant outlet of the fuel cell stack is connected to the refrigerant inlet of the first heat exchanger through the refrigerant circulation pump.

[0015] Further, the fuel cell stack is provided with a second temperature sensor. When the temperature detected by the second temperature sensor is less than the second set value, by controlling the fourth solenoid valve, the third outlet of the first refrigerant tank is connected to the refrigerant inlet of the fuel cell stack through the first heater; when the temperature detected by the second temperature sensor is greater than or equal to the second set value and less than the third set value, by controlling the fifth solenoid valve, the second outlet of the first refrigerant tank is connected to the refrigerant inlet of the fuel cell stack; when the temperature detected by the second temperature sensor is greater than or equal to the third set value, by controlling the sixth solenoid valve, the first outlet of the first refrigerant tank is connected to the refrigerant inlet of the fuel cell stack through the radiator.

[0016] Further, the power battery subsystem includes a first generator, a second refrigerant tank, a seventh solenoid valve, a second heat exchanger, a second compressor, a first turbine expander, a second condenser, a third refrigerant tank, a second turbine expander, a second generator, and a third compressor;

[0017] The refrigerant water outlet I of the vaporizer, the second refrigerant tank, the seventh solenoid valve, the second heat exchanger, the second compressor, the first turbine expander, the second condenser, and the refrigerant water inlet F of the vaporizer form a circulation loop; the first turbine expander is connected to the first generator for generating electric energy; the first generator is connected to the lithium battery; the lithium battery is used to drive the motor.

[0018] A third refrigerant tank is installed at the bottom of the lithium battery and the motor to absorb the waste heat generated by the lithium battery and the motor. The third refrigerant tank, the second turbine expander, the second heat exchanger, and the third compressor form a circulation loop. The second generator is connected to the second turbine expander to generate electric energy.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. In the vehicle-mounted hydrogen fuel cell cold energy utilization system described in the present invention, compared with the previous cold energy utilization methods, the cold energy utilization during the liquid hydrogen vaporization process is more sufficient, and the recycling of energy is more sufficient.

[0021] 2. The vehicle-mounted hydrogen fuel cell cold energy utilization system described in the present invention realizes the energy interaction during the system operation process, makes full use of the large amount of waste heat of the lithium battery and the motor, and realizes the interaction between the cold energy and the system heat.

[0022] 3. In the vehicle-mounted hydrogen fuel cell cold energy utilization system described in the present invention, in the power battery subsystem, the combined cycle method of reasonably using the direct expansion method and the Rankine cycle method is adopted, and the efficiency in the power battery subsystem can reach up to 50% at most and the construction cost is low.

[0023] 4. In the vehicle-mounted hydrogen fuel cell cold energy utilization system described in the present invention, the circulating refrigerant is a mixture of 66% ethylene glycol, 33.6% deionized water, and 0.4% aluminum oxide. While meeting the heat exchange requirements with hydrogen and the operation requirements of the vehicle in a low-temperature environment, the cooling performance of the refrigerant is also improved to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. The following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained obviously without creative efforts based on these drawings.

[0025] Figure 1 It is the working principle diagram of the vehicle-mounted liquid hydrogen fuel cell cold energy utilization system described in the present invention.

[0026] Figure 2 It is the working principle diagram of the power battery subsystem described in the present invention.

[0027] In the figure:

[0028] 1 - Liquid hydrogen storage tank; 2 - First solenoid valve; 3 - Vaporizer; 4 - Expansion tank; 5 - Second solenoid valve; 6 - Water pump; 7 - First compressor; 8 - First condenser; 9 - Evaporator; 10 - Four-way valve; 11 - Expansion throttle valve; 12 - Blower; 14 - Third solenoid valve; 15 - First heat exchanger; 16 - First refrigerant tank; 17 - Fourth solenoid valve; 18 - First heater; 19 - Fifth solenoid valve; 21 - Sixth solenoid valve; 22 - Radiator; 24 - Fuel cell stack; 25 - Refrigerant circulation pump; 26 - Pump; 27 - Pressure regulating valve; 28 - First three-way valve; 29 - Second heater; 30 - Second three-way valve; 31 - Lithium battery; 32 - Motor; 33 - Second refrigerant tank; 34 - Seventh solenoid valve; 35 - Second heat exchanger; 36 - Second compressor; 37 - First turbine expander; 38 - Second condenser; 39 - Third refrigerant tank; 40 - Second turbine expander; 41 - Second generator; 42 - Third compressor; 43 - First generator. Detailed implementation manners

[0029] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0030] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as a limitation of the present invention.

[0031] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0032] In the present invention, unless otherwise clearly specified and defined, terms such as "installation", "connection", "linkage", "fixation" and the like shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention may be understood according to specific circumstances.

[0033] As Figure 1 shown, the vehicle-mounted liquid hydrogen fuel cell cold energy utilization system of the present invention includes a fuel cell stack 24, a hydrogen supply subsystem, an air-conditioning subsystem, a fuel cell cooling subsystem and a power battery subsystem. The hydrogen supply subsystem is communicated with the fuel cell stack 24 and is used for converting liquid hydrogen into gaseous hydrogen and then inputting it into the fuel cell stack 24; the air-conditioning subsystem is communicated with the hydrogen supply subsystem and is used for obtaining the cold energy released during the conversion of liquid hydrogen into gaseous hydrogen; the fuel cell cooling subsystem is communicated with the hydrogen supply subsystem and cools or preheats the fuel cell stack 24 by obtaining the cold energy of gaseous hydrogen; the power battery subsystem is communicated with the hydrogen supply subsystem and is used for generating electricity by recovering the preheat generated by the hydrogen supply subsystem. Water is used as the refrigerant in the air-conditioning subsystem, and the refrigerants in the fuel cell cooling subsystem and the power battery subsystem are both mixtures of 66% ethylene glycol, 33.6% deionized water and 0.4% aluminum oxide, making full use of the cold quantity of liquid hydrogen, and at the same time using the waste heat generated by the lithium battery 31 and the motor 32 during the circulation process to generate energy interaction and improve the energy utilization of the whole system.

[0034] The hydrogen supply subsystem includes a liquid hydrogen storage tank 1, a first solenoid valve 2, a vaporizer 3, a third solenoid valve 14, a first heat exchanger 15, a pump 26, a pressure regulating valve 27, a first three-way valve 28, a second heater 29, and a second three-way valve 30; the liquid hydrogen storage tank 1 is successively connected to the first solenoid valve 2, the vaporizer 3, the third solenoid valve 14, the first heat exchanger 15, the pump 26, the pressure regulating valve 27, and the first three-way valve 28, and the liquid hydrogen outlet of the liquid hydrogen storage tank 1 is connected to the water inlet of the first solenoid valve 2; the water outlet of the first solenoid valve 2 is connected to the liquid hydrogen inlet of the vaporizer 3; the gaseous hydrogen outlet of the vaporizer 13 is connected to the gaseous hydrogen inlet of the third solenoid valve 14; the gaseous hydrogen outlet of the third solenoid valve 14 is connected to the gaseous hydrogen inlet of the first heat exchanger 15; the gaseous hydrogen outlet of the first heat exchanger 15 is connected to the gaseous hydrogen inlet of the pump 26; the gaseous hydrogen outlet of the pump 26 is connected to the gaseous hydrogen inlet of the pressure regulating valve 27; the gaseous hydrogen outlet of the pressure regulating valve 27 is connected to the gaseous hydrogen inlet of the first three-way valve 28; one outlet of the first three-way valve 28 is connected to the second heater 29, another outlet of the first three-way valve 28 is connected to one inlet of the second three-way valve 30, the second heater 29 is connected to the other inlet of the second three-way valve 30, and the outlet of the second three-way valve 30 is connected to the fuel cell stack 24; a first temperature sensor is installed at the outlet of the first heat exchanger 15. When the temperature detected by the first temperature sensor is greater than or equal to the first set value, the outlet of the pump 26 is connected to the fuel cell stack 24 through the second three-way valve 30 by controlling the first three-way valve 28; when the temperature detected by the first temperature sensor is less than the first set value, the outlet of the pump 26 is successively connected to the fuel cell stack 24 through the second heater 29 and the second three-way valve 30 by controlling the first three-way valve 28. Hydrogen enters the fuel cell stack and undergoes a chemical reaction with oxygen in the air under the action of a catalyst to generate electric energy; the electric energy generated by the fuel cell stack 24 is input into the lithium battery 31.

[0035] The liquid hydrogen in the liquid hydrogen storage tank 1 has its flow rate controlled by the first solenoid valve 2 and enters the vaporizer 3 to exchange heat with water and refrigerant. Part of the cold energy is applied to the air-conditioning subsystem, and part of the cold energy is applied to the power battery subsystem. In the first heat exchanger 15, there is liquid hydrogen that has not been completely vaporized, forming a gas-liquid two-phase hydrogen. The first heat exchanger 15 can also apply the cold energy to the fuel cell cooling subsystem. The hydrogen gas vaporized by the vaporizer 13 has its flow rate controlled by the third solenoid valve 14 and enters the first heat exchanger 15 to exchange heat with the refrigerant and increase in temperature. A pressure sensor and a first temperature sensor are arranged at the gas hydrogen outlet of the first heat exchanger 15. The hydrogen gas is driven by the pump 26 into the pressure regulating valve 27. The pressure regulating valve 27 controls the regulation of the hydrogen gas pressure according to the pressure sensor to reach the pressure of the hydrogen gas required by the fuel cell stack. Then the hydrogen gas enters the second three-way valve 28 and selectively follows different circuits: According to the monitoring of the first temperature sensor, when the temperature of the gas hydrogen is lower than the temperature required by the fuel cell stack, it is heated by the second heater 29 and then enters the fuel cell stack 24; when the temperature of the gas hydrogen reaches the temperature required by the fuel cell stack, it directly enters the fuel cell stack 24.

[0036] The vaporizer 3 has a cooling water inlet E, a refrigerant inlet F, a liquid hydrogen inlet G, a cooling water outlet H, a refrigerant outlet I, and a gas hydrogen and liquid hydrogen outlet J; the liquid hydrogen flows in from the liquid hydrogen inlet G to the shell side of the shell-and-tube vaporizer and flows between the tube bundles according to the distribution of the internal baffle plates. After part of the liquid hydrogen is vaporized, the gas-liquid two-phase mixed hydrogen flows out from the gas hydrogen and liquid hydrogen outlet J; the refrigerant for the power battery subsystem flows in from the refrigerant inlet F into the shell side and then flows into the refrigerant heat exchange tube bundle through a pipeline. The refrigerant first exchanges heat with the cold energy during the liquid hydrogen vaporization process, has a relatively fast flow rate, and fully absorbs the cold energy of the liquid hydrogen vaporization, and finally flows out from the refrigerant outlet I; the cooling water for the air-conditioning system flows in from the cooling water inlet E into the cooling water heat exchange tube bundle. The cooling water heat exchange tube bundle is surrounded by the refrigerant heat exchange tube bundle. The flow rate of the cooling water is slower than that of the refrigerant. The cooling water absorbs part of the cold energy of the refrigerant after heat exchange with the liquid hydrogen and then flows out from the cooling water outlet H; the liquid hydrogen vaporization is completed while exchanging heat with the cooling water and the refrigerant.

[0037] Through the design of the water pipe distribution and different flow rates in the water pipes of the vaporizer 3 of the present invention, two refrigerants can simultaneously exchange heat with the cold energy of the liquid hydrogen vaporization. Different flow rates can change the speed of heat exchange of the refrigerants in each water pipe, which can completely avoid the problem that the cooling circulating water in the air-conditioning subsystem absorbs too much cold energy and causes icing.

[0038] The air-conditioning subsystem includes an expansion tank 4, a second solenoid valve 5, a water pump 6, a first compressor 7, a four-way valve 10, a first condenser 8, an evaporator 9, an expansion throttle valve 11, and a blower 12. The cooling water outlet H of the vaporizer 3 is sequentially connected to the expansion tank 4, the second solenoid valve 5, the water pump 6, the first compressor 7, and the interface d of the four-way valve 10. The interface c of the four-way valve 10 is sequentially connected to the interface a of the four-way valve 10 through the first condenser 8 and the evaporator 9. The interface b of the four-way valve 10 is connected to the cooling water outlet E of the vaporizer 3 through the expansion throttle valve 11.

[0039] When the air-conditioning subsystem is in the cooling mode, by controlling the four-way valve 10, the interface d of the four-way valve 10 is connected to the interface c of the four-way valve 10, and the interface a of the four-way valve 10 is connected to the interface b of the four-way valve 10. In the cooling mode, liquid hydrogen exchanges heat with the cooling circulating water in the vaporizer 3 to transfer cold energy to the cooling circulating water. The cooling water outlet H of the vaporizer 3 is connected to the water inlet of the expansion tank 4. The water outlet of the expansion tank 4 is connected to the water inlet of the second solenoid valve 5. The water outlet of the second solenoid valve 5 is connected to the water inlet of the water pump 6. The water outlet of the water pump 6 is connected to the water inlet of the first compressor 7. The water outlet of the first compressor 7 is connected to the interface d of the four-way valve 10. The interface d of the four-way valve 10 is connected to the interface c of the four-way valve 10. The interface c of the four-way valve 10 is connected to the water inlet of the first condenser 8. The water outlet of the first condenser 8 is connected to the water inlet of the evaporator 9. The water outlet of the evaporator 9 is connected to the interface a of the four-way valve 10. The interface a of the four-way valve 10 is connected to the interface b of the four-way valve 10. The interface b of the four-way valve 10 is connected to the water inlet of the expansion throttle valve 11. The water outlet of the expansion throttle valve 11 is connected to the cooling water outlet E of the vaporizer 3. During the process, the cooling circulating water undergoes multiple changes in temperature, pressure, and state to complete the cycle of air-conditioning refrigeration.

[0040] Liquid hydrogen exchanges heat with the cooling circulating water in the vaporizer 3, transferring cold energy to the cooling circulating water. The second solenoid valve 5 controls the flow rate of the cooling circulating water, and the water pump 6 drives the cooling circulating water to be transported into the compressor 7, changing from a low-temperature and low-pressure liquid to a high-temperature and high-pressure gas, and entering the four-way valve 10. The interface d of the four-way valve 10 is connected to the interface c of the four-way valve 10, and then enters the condenser 8 to form a low-temperature and low-pressure liquid, and then enters the evaporator 9 to vaporize and absorb heat, reducing the temperature of the surrounding air. The gas coming out of the evaporator 9 passes through the four-way valve 10, and the interface a of the four-way valve 10 is connected to the interface b of the four-way valve 10. The gas then passes through the expansion throttle valve 11, where it undergoes throttling and pressure reduction and is compressed into a liquid, regulating and controlling the flow rate. At the same time, during this process, the air cooled by vaporization in the evaporator 9 is introduced into the expansion throttle valve 11 through a pipeline, and the blower 12 arranged at the front end of the expansion throttle valve 11 blows the cold air into the cab to achieve a refrigeration effect. The liquid in the expansion throttle valve 11 then flows back into the vaporizer 3 to realize the air-conditioning refrigeration cycle;

[0041] When the air-conditioning subsystem is in the heating mode, by controlling the four-way valve 10, the interface d of the four-way valve 10 is connected to the interface a of the four-way valve 10, and the interface c of the four-way valve 10 is connected to the interface b of the four-way valve 10. In the heating mode, liquid hydrogen exchanges heat with the cooling circulating water in the vaporizer 3, transferring cold energy to the cooling circulating water. The cooling water outlet H of the vaporizer 3 is connected to the water inlet of the expansion tank 4; the water outlet of the expansion tank 4 is connected to the water inlet of the second solenoid valve 5; the water outlet of the second solenoid valve 5 is connected to the water inlet of the water pump 6; the water outlet of the water pump 6 is connected to the water inlet of the first compressor 7; the water outlet of the first compressor 7 is connected to the interface d of the four-way valve 10; the interface d of the four-way valve 10 is connected to the interface a of the four-way valve 10, and the interface a of the four-way valve 10 is connected to the water inlet of the evaporator 9; the water outlet of the evaporator 9 is connected to the water inlet of the first condenser 8; the water outlet of the first condenser 8 is connected to the interface c of the four-way valve 10; the interface c of the four-way valve 10 is connected to the interface b of the four-way valve 10, and the interface b of the four-way valve 10 is connected to the water inlet of the expansion throttle valve 11; the water outlet of the expansion throttle valve 11 is connected to the cooling water outlet E of the vaporizer 3. During the process, the cooling circulating water undergoes multiple changes in temperature, pressure, and state to complete the air-conditioning heating cycle;

[0042] The liquid hydrogen exchanges heat with the cooling circulating water in the vaporizer 3, and transfers cold energy to the cooling circulating water. The second solenoid valve 5 controls the flow rate of the cooling circulating water. The cooling circulating water is driven by the water pump 6 to be transmitted to the compressor 7, and changes from a low-temperature and low-pressure liquid to a high-temperature and high-pressure gas, and enters the four-way valve 10. The interface d of the four-way valve 10 is connected to the interface a of the four-way valve 10, and then enters the evaporator 9, and then enters the condenser 8 to form a low-temperature and high-pressure liquid, releasing a large amount of energy to the external air, so that the surrounding temperature increases to achieve a heating effect, and then enters the four-way valve 10. The interface c of the four-way valve 10 is connected to the interface b of the four-way valve 10. The liquid then passes through the expansion throttle valve 9 to adjust and control the flow, and then flows into the vaporizer 3 to realize the air conditioning heating cycle.

[0043] The fuel cell cooling subsystem includes a first refrigerant tank 16, a fourth solenoid valve 17, a first heater 18, a fifth solenoid valve 19, a sixth solenoid valve 21, a radiator 22 and a refrigerant circulation pump 25; the refrigerant outlet of the first heat exchanger 15 is connected to the first refrigerant tank 16, the first outlet of the first refrigerant tank 16 is connected to the sixth solenoid valve 21, the radiator 22 and the refrigerant inlet of the fuel cell stack 24 in sequence, the second outlet of the first refrigerant tank 16 is connected to the fifth solenoid valve 19 and the refrigerant inlet of the fuel cell stack 24 in sequence, and the third outlet of the first refrigerant tank 16 is connected to the fourth solenoid valve 17, the first heater 18 and the refrigerant inlet of the fuel cell stack 24 in sequence; the refrigerant outlet of the fuel cell stack 24 is connected to the refrigerant inlet of the first heat exchanger 15 through the refrigerant circulation pump 25.

[0044] The fuel cell stack 24 is provided with a second temperature sensor. When the temperature detected by the second temperature sensor is lower than the second set value, the third outlet of the first refrigerant tank 16 is connected to the refrigerant inlet of the fuel cell stack 24 through the first heater 18 by controlling the fourth solenoid valve 17; when the temperature detected by the second temperature sensor is greater than or equal to the second set value, and the temperature detected by the second temperature sensor is lower than the third set value, the second outlet of the first refrigerant tank 16 is connected to the refrigerant inlet of the fuel cell stack 24 by controlling the fifth solenoid valve 19; when the temperature detected by the second temperature sensor is greater than or equal to the third set value, the first outlet of the first refrigerant tank 16 is connected to the refrigerant inlet of the fuel cell stack 24 through the radiator 22 by controlling the sixth solenoid valve 21.

[0045] In the embodiment, the temperature displayed by the second temperature sensor is T 温 , the second set value T 设二 The third setting value T is 70℃. 设三 At 80°C, when T 温 <T 设二When the temperature is T, the third refrigerant outlet of the first refrigerant tank 16 is communicated with the refrigerant inlet of the fourth solenoid valve 17, the refrigerant inlet of the fourth solenoid valve 17 is communicated with the refrigerant inlet of the first heater 18, and the refrigerant outlet of the first heater 18 is communicated with the refrigerant inlet of the fuel cell stack 24; when T 设二 <T 温 <T 设三 When the temperature is T, the second outlet of the first refrigerant tank 16 is communicated with the refrigerant inlet of the fifth solenoid valve 19, and the refrigerant outlet of the fifth solenoid valve 19 is communicated with the refrigerant inlet of the fuel cell stack 24; when T 温 >T 设三 When the temperature is T, the refrigerant outlet 3 of the first refrigerant tank 16 is communicated with the refrigerant inlet of the sixth solenoid valve 21, the refrigerant outlet of the sixth solenoid valve 21 is communicated with the refrigerant inlet of the radiator 22, and the refrigerant outlet of the radiator 22 is communicated with the refrigerant inlet of the fuel cell stack 24; the refrigerant outlet of the fuel cell stack 24 is communicated with the refrigerant inlet of the refrigerant circulation pump 25; the refrigerant outlet of the refrigerant circulation pump 25 is communicated with the refrigerant inlet of the second heat exchanger 15, completing the fuel cell cooling cycle.

[0046] The refrigerant in the fuel cell cooling subsystem is a mixture of 66% ethylene glycol, 33.6% deionized water, and 0.4% aluminum oxide. The refrigerant that absorbs cold energy flows into the first refrigerant tank 16. The safe, efficient, and stable operating temperature of the fuel cell stack 24 is 70°C - 80°C. A second temperature sensor is provided at the refrigerant inlet of the fuel cell stack 24 to detect the temperature of the fuel cell stack 24. When the vehicle is cold-started, the temperature of the fuel cell stack 24 is lower than the safe, efficient, and stable operating temperature. To quickly raise the temperature of the fuel cell stack 24 to the appropriate operating temperature range, the flow rate of the refrigerant is controlled by the fourth solenoid valve 17, and after being heated by the first heater 18, it enters the fuel cell stack 24; when it reaches the safe, efficient, and stable operating temperature range, the flow rate is controlled by the fifth solenoid valve 19, and the refrigerant directly enters the fuel cell stack 24; when the temperature is higher than the safe, efficient, and stable operating temperature range, the flow rate of the refrigerant is controlled by the sixth solenoid valve 21, and through the channel with the radiator 22, forced heat dissipation is carried out to reduce the refrigerant temperature and then enter the fuel cell stack 24. After cooling the fuel cell stack 24, the heated refrigerant flows out of the fuel cell stack 24, is driven by the refrigerant circulation pump 25 to flow into the first heat exchanger 15 to cool down, and then enters the first refrigerant tank 16 to continue participating in the fuel cell cooling, completing the fuel cell cooling cycle.

[0047] Such as Figure 2As shown, the power battery subsystem includes a first generator 43, a second refrigerant tank 33, a seventh solenoid valve 34, a second heat exchanger 35, a second compressor 36, a first turbine expander 37, a second condenser 38, a third refrigerant tank 39, a second turbine expander 40, a second generator 41, and a third compressor 42; the refrigerant water outlet I of the vaporizer 3, the second refrigerant tank 33, the seventh solenoid valve 34, the second heat exchanger 35, the second compressor 36, the first turbine expander 37, the second condenser 38, and the refrigerant water inlet F of the vaporizer 3 form a circulation loop; the first turbine expander 37 is connected to the first generator 43 for generating electric energy; the first generator 43 is connected to the lithium battery 31; the lithium battery 31 is used to drive the motor 32, and the third refrigerant tank 39 is installed at the bottom of the lithium battery 31 and the motor 32 for absorbing the waste heat generated by the lithium battery 31 and the motor 32; the third refrigerant tank 39, the second turbine expander 40, the second heat exchanger 35, and the third compressor 42 form a circulation loop; the second generator 41 is connected to the second turbine expander 40 for generating electric energy.

[0048] As Figure 2 shown in the figure, the refrigerant water outlet I of the vaporizer 3 is communicated with the refrigerant inlet of the second refrigerant tank 33; the refrigerant outlet of the second refrigerant tank 33 is communicated with the refrigerant inlet of the seventh solenoid valve 34; the refrigerant outlet of the seventh solenoid valve 34 is communicated with the refrigerant inlet of the second heat exchanger 35; the refrigerant outlet of the second heat exchanger 35 is communicated with the refrigerant inlet of the second compressor 36; the air outlet of the second compressor 36 is communicated with the air inlet of the first turbine expander 37; the air outlet of the first turbine expander 37 is communicated with the air inlet of the second condenser 38; the refrigerant outlet of the second condenser 38 is communicated with the refrigerant water inlet F of the vaporizer 3; the first turbine expander 37 drives the first generator 43 to operate; the first generator 43 is connected to the lithium battery 31; the lithium battery 31 is used to drive the motor 32, and the third refrigerant tank 39 is installed at the bottom of the lithium battery 31 and the motor 32 for absorbing the waste heat generated by the lithium battery 31 and the motor 32; the air outlet of the third refrigerant tank 39 is communicated with the air inlet of the second turbine expander 40; the air outlet of the second turbine expander 40 is communicated with the air inlet of the second heat exchanger 35; the air outlet of the second heat exchanger 35 is communicated with the refrigerant inlet of the third compressor 42; the refrigerant outlet of the third compressor 42 is communicated with the refrigerant inlet of the third refrigerant tank; the second turbine expander 40 drives the second generator 41 to operate; the waste heat utilization cycle of the motor and the lithium battery is completed.

[0049] The refrigerant in the power battery subsystem is a mixture of 66% ethylene glycol, 33.6% deionized water, and 0.4% aluminum oxide. The refrigerant flow rate is adjusted by the seventh solenoid valve 34. The refrigerant after absorbing the cold enters the second heat exchanger 35 for heat exchange, forming a normal-temperature and low-pressure gas, which enters the second compressor 36 to form a normal-temperature and high-pressure gas, and then expands through the first turbine expander 37 to drive the first generator 43 to operate. After the refrigerant comes out of the first expander 37, it is cooled to a medium-temperature and high-pressure liquid by the second condenser 38 and returns to the vaporizer 3 to complete the refrigerant cycle.

[0050] A large amount of waste heat will be generated on the surfaces of the lithium battery 31 and the first motor 32. The waste heat is exchanged with the refrigerant in the third refrigerant tank 39. The refrigerant here is a mixture of 66% ethylene glycol, 33.6% deionized water, and 0.4% aluminum oxide, forming a high-temperature and high-pressure gas, which then expands through the second turbine expander 40 to drive the second generator 41 to operate. The normal-temperature and low-pressure gas generated by the second turbine expander 40 enters the second heat exchanger 35 to exchange heat with the refrigerant, forming a low-temperature and low-pressure liquid, which enters the third compressor 42 to form a low-temperature and high-pressure liquid, and then enters the third refrigerant tank 39 to form a high-temperature and high-pressure gas, completing the waste heat utilization cycle of the motor and the lithium battery.

[0051] It should be understood that although this specification is described according to each embodiment, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0052] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent embodiments or changes made without departing from the technical spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A vehicle-mounted liquid hydrogen fuel cell cold energy utilization system, characterized in that, It includes a fuel cell stack (24), a hydrogen supply subsystem, an air conditioning subsystem, a fuel cell cooling subsystem, and a power battery subsystem; The hydrogen supply subsystem is connected to the fuel cell stack (24) and is used to convert liquid hydrogen into gaseous hydrogen and then input it into the fuel cell stack (24); the air conditioning subsystem is connected to the hydrogen supply subsystem and is used to obtain the cold energy released during the conversion of liquid hydrogen into gaseous hydrogen; the fuel cell cooling subsystem is connected to the hydrogen supply subsystem and cools or preheats the fuel cell stack (24) by obtaining the cold energy of the gaseous hydrogen; the power battery subsystem is connected to the hydrogen supply subsystem and is used for power generation by recovering the waste heat generated by the hydrogen supply subsystem; The hydrogen supply subsystem includes a liquid hydrogen storage tank (1), a first solenoid valve (2), a vaporizer (3), a third solenoid valve (14), a first heat exchanger (15), a pump (26), a pressure regulating valve (27), a first three-way valve (28), a second heater (29), and a second three-way valve (30); the liquid hydrogen storage tank (1) is sequentially connected to the first solenoid valve (2), the vaporizer (3), the third solenoid valve (14), the first heat exchanger (15), the pump (26), the pressure regulating valve (27), and the first three-way valve (28). One outlet of the first three-way valve (28) is connected to the second heater (29), and the other outlet of the first three-way valve (28) is connected to one inlet of the second three-way valve (30). The second heater (29) is connected to the other inlet of the second three-way valve (30), and the outlet of the second three-way valve (30) is connected to the fuel cell stack (24); a first temperature sensor is installed at the outlet of the first heat exchanger (15). When the temperature detected by the first temperature sensor is greater than or equal to the first set value, the pump (26) outlet is connected to the fuel cell stack (24) through the second three-way valve (30) by controlling the first three-way valve (28); when the temperature detected by the first temperature sensor is less than the first set value, the pump (26) outlet is connected to the fuel cell stack (24) through the second heater (29) and the second three-way valve (30) by controlling the first three-way valve (28); the electric energy generated by the fuel cell stack (24) is input into the lithium battery (31); The fuel cell cooling subsystem includes a first refrigerant tank (16), a fourth solenoid valve (17), a first heater (18), a fifth solenoid valve (19), a sixth solenoid valve (21), a radiator (22), and a refrigerant circulation pump (25); The refrigerant outlet of the first heat exchanger (15) is communicated with the first refrigerant tank (16). The first outlet of the first refrigerant tank (16) is successively communicated with the refrigerant inlet of the sixth solenoid valve (21), the radiator (22), and the fuel cell stack (24). The second outlet of the first refrigerant tank (16) is successively communicated with the refrigerant inlet of the fifth solenoid valve (19) and the fuel cell stack (24). The third outlet of the first refrigerant tank (16) is successively communicated with the refrigerant inlet of the fourth solenoid valve (17), the first heater (18), and the fuel cell stack (24). The refrigerant outlet of the fuel cell stack (24) is communicated with the refrigerant inlet of the first heat exchanger (15) through the refrigerant circulation pump (25). The power battery subsystem includes a first generator (43), a second refrigerant tank (33), a seventh solenoid valve (34), a second heat exchanger (35), a second compressor (36), a first turbine expander (37), a second condenser (38), a third refrigerant tank (39), a second turbine expander (40), a second generator (41), and a third compressor (42). The refrigerant water outlet I of the vaporizer (3) and the refrigerant water inlet F of the second refrigerant tank (33), the seventh solenoid valve (34), the second heat exchanger (35), the second compressor (36), the first turbine expander (37), the second condenser (38), and the vaporizer (3) form a circulation loop. The first turbine expander (37) is connected to the first generator (43) for generating electric energy. The first generator (43) is connected to the lithium battery (31). The lithium battery (31) is used to drive the motor (32). The third refrigerant tank (39) is installed at the bottoms of the lithium battery (31) and the motor (32) to absorb the waste heat generated by the lithium battery (31) and the motor (32). The third refrigerant tank (39) forms a circulation loop with the second turbine expander (40), the second heat exchanger (35), and the third compressor (42). The second generator (41) is connected to the second turbine expander (40) for generating electric energy.

2. The on-vehicle liquid hydrogen fuel cell cold energy utilization system according to claim 1, wherein The air conditioning subsystem includes an expansion tank (4), a second solenoid valve (5), a water pump (6), a first compressor (7), a four-way valve (10), a first condenser (8), an evaporator (9), an expansion throttle valve (11), and a blower (12). The cooling water outlet H of the vaporizer (3) is successively communicated with the expansion tank (4), the second solenoid valve (5), the water pump (6), the first compressor (7), and the interface d of the four-way valve (10). The interface c of the four-way valve (10) is successively communicated with the interface a of the four-way valve (10) through the first condenser (8) and the evaporator (9). The interface b of the four-way valve (10) is communicated with the cooling water outlet E of the vaporizer (3) through the expansion throttle valve (11).

3. The on-vehicle liquid hydrogen fuel cell cold energy utilization system according to claim 2, wherein, When the air conditioning subsystem is in the cooling mode, by controlling the four-way valve (10), the interface d of the four-way valve (10) is communicated with the interface c of the four-way valve (10), and the interface a of the four-way valve (10) is communicated with the interface b of the four-way valve (10); when the air conditioning subsystem is in the heating mode, by controlling the four-way valve (10), the interface d of the four-way valve (10) is communicated with the interface a of the four-way valve (10), and the interface c of the four-way valve (10) is communicated with the interface b of the four-way valve (10).

4. The on-vehicle liquid hydrogen fuel cell cold energy utilization system according to claim 1, characterized in that, The fuel cell stack (24) is provided with a second temperature sensor. When the temperature detected by the second temperature sensor is less than the second set value, by controlling the fourth solenoid valve (17), the third outlet of the first refrigerant tank (16) is communicated with the refrigerant inlet of the fuel cell stack (24) through the first heater (18); when the temperature detected by the second temperature sensor is greater than or equal to the second set value and less than the third set value, by controlling the fifth solenoid valve (19), the second outlet of the first refrigerant tank (16) is communicated with the refrigerant inlet of the fuel cell stack (24); when the temperature detected by the second temperature sensor is greater than or equal to the third set value, by controlling the sixth solenoid valve (21), the first outlet of the first refrigerant tank (16) is communicated with the refrigerant inlet of the fuel cell stack (24) through the radiator (22).

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