Liquid hydrogen cold energy utilization system for fuel cell and fuel cell

Abstract

The liquid hydrogen cold energy utilization system for the fuel cell comprises a liquid hydrogen tank, a first-stage heat exchange circulation unit and a second-stage heat exchange circulation unit, the first-stage heat exchange circulation unit comprises a first heat exchanger and a whole vehicle auxiliary cooling system, and the second-stage heat exchange circulation unit comprises a second heat exchanger and an electric pile. According to the scheme, step-by-step heat exchange circulation is adopted, the temperature of cooling liquid of the whole vehicle auxiliary heat dissipation system is low, the cooling liquid serves as a heating medium of the first-stage heat exchange circulation, primary heat exchange is conducted on low-temperature gaseous hydrogen from a liquid hydrogen tank, and therefore the whole vehicle auxiliary heat dissipation energy consumption is reduced; the heat exchange circulation temperature of stack tail gas mixed gas of the fuel cell is close to the running temperature of the stack, the stack tail gas mixed gas serves as a heating medium of the second-stage heat exchange circulation, secondary heat exchange is conducted on low-temperature gaseous hydrogen subjected to primary heat exchange of the first-stage heat exchange circulation, and waste heat of the fuel cell tail gas is utilized. The system is simple in structure, and liquid hydrogen cold energy can be effectively and efficiently utilized. The invention also provides a fuel cell.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells, and in particular relates to a liquid hydrogen cooling energy utilization system for fuel cells and a fuel cell. Background Art

[0002] As a highly efficient and environmentally friendly energy conversion device, proton exchange membrane fuel cells (PEMFCs) hold broad application prospects in rail transit. Hydrogen fuel cell locomotives, with their significant advantages such as high efficiency, zero emissions, and zero pollution, have become a key development direction for new energy locomotives. Liquid hydrogen, as an ideal energy carrier, possesses extremely high hydrogen storage density and is easy to store and transport. It can provide sufficient hydrogen for PEMFCs, effectively meeting the locomotive's requirements for high power output, high hydrogen storage capacity, and long driving range, ensuring efficient operation.

[0003] However, in practical applications, low-temperature liquid hydrogen must be heated before entering the fuel cell stack to ensure that it meets the intake temperature standard required by the fuel cell. At the same time, the fuel cell generates a large amount of waste heat during operation. If the cold energy released during the liquid hydrogen heating process and the heat energy generated during the operation of the fuel cell can be reasonably utilized, a simple and efficient thermal management system can be designed. This will help significantly reduce the auxiliary power consumption of the fuel cell system and further improve the working efficiency and service life of the fuel cell. In addition, this optimized thermal management strategy is also expected to reduce the auxiliary energy consumption of the entire vehicle, thereby effectively reducing the operating cost of the locomotive, which is of vital importance to promoting the sustainable development of fuel cell locomotives equipped with liquid hydrogen.

[0004] In summary, how to design a simple and efficient liquid hydrogen cooling energy utilization system and method for fuel cells to overcome the shortcomings of existing technologies has become an important issue that needs to be urgently addressed in this technical field. Summary of the Invention

[0005] The object of the present invention is to provide a liquid hydrogen cold energy utilization system for a fuel cell and a fuel cell, which has a simple structure and can effectively realize the efficient utilization of liquid hydrogen cold energy.

[0006] To solve the above technical problems, the present invention provides a liquid hydrogen cold energy utilization system for a fuel cell, comprising a liquid hydrogen tank, a primary heat exchange circulation unit and a secondary heat exchange circulation unit. The primary heat exchange circulation unit comprises a first heat exchanger and a vehicle auxiliary heat dissipation system, and the secondary heat exchange circulation unit comprises a second heat exchanger and a fuel cell stack.

[0007] The outlet of the liquid hydrogen tank is connected to the refrigerant inlet of the first heat exchanger, the heat medium inlet of the first heat exchanger is connected to the coolant outlet of the auxiliary cooling system of the whole vehicle, the heat medium outlet of the first heat exchanger is connected to the coolant inlet of the auxiliary cooling system of the whole vehicle, the refrigerant outlet of the first heat exchanger is connected to the refrigerant inlet of the second heat exchanger, the refrigerant outlet of the second heat exchanger is connected to the hydrogen inlet of the fuel cell stack, the gas outlet of the fuel cell stack is connected to the heat medium inlet of the second heat exchanger, and the heat medium outlet of the second heat exchanger is connected to the mixed exhaust port of the whole vehicle.

[0008] Optionally, in the above-mentioned liquid hydrogen cooling energy utilization system for fuel cells, the primary heat exchange circulation unit further includes a converter, a thermostat and a three-way valve;

[0009] The inlet of the thermostat is connected to the coolant outlet of the auxiliary cooling system of the vehicle, and the two outlets of the thermostat are connected to the heat medium inlet of the first heat exchanger and the coolant inlet of the converter respectively;

[0010] The outlet of the three-way valve is communicated with the coolant inlet of the vehicle auxiliary heat dissipation system, and the two inlets of the three-way valve are communicated with the heat medium outlet of the first heat exchanger and the coolant outlet of the converter respectively.

[0011] Optionally, in the above-mentioned liquid hydrogen cooling energy utilization system for fuel cells, the first-stage heat exchange circulation unit further includes a converter;

[0012] The heat medium outlet of the first heat exchanger is communicated with the coolant inlet of the converter, and the coolant outlet of the converter is communicated with the coolant inlet of the auxiliary heat dissipation system of the whole vehicle.

[0013] Optionally, in the above-mentioned liquid hydrogen cooling energy utilization system for fuel cells, the converter is a DC / DC converter.

[0014] Optionally, in the above-mentioned liquid hydrogen cold energy utilization system for fuel cells, the first-stage heat exchange circulation unit also includes a water pump, which is connected in series between the heat medium inlet of the first heat exchanger and the coolant outlet of the vehicle auxiliary cooling system.

[0015] Optionally, in the above-mentioned liquid hydrogen cold energy utilization system for fuel cells, the secondary heat exchange circulation unit also includes a water separator, the air inlet of the water separator is connected to the gas outlet of the fuel cell stack, and the gas outlet of the water separator is connected to the heat medium inlet of the second heat exchanger.

[0016] Optionally, in the above-mentioned liquid hydrogen cold energy utilization system for fuel cells, the liquid outlet of the water separator is connected to the mixed discharge port of the whole vehicle.

[0017] Optionally, in the above-mentioned liquid hydrogen cold energy utilization system for fuel cells, the secondary heat exchange circulation unit further includes an exhaust gas muffler, which is connected in series between the air inlet of the water separator and the gas outlet of the fuel cell stack.

[0018] Optionally, in the above-mentioned liquid hydrogen cold energy utilization system for fuel cells, the secondary heat exchange circulation unit further includes a hydrogen circulation pump, which is connected in series between the refrigerant outlet of the second heat exchanger and the hydrogen inlet of the fuel cell stack.

[0019] The present invention also provides a fuel cell, comprising the liquid hydrogen cooling energy utilization system for the fuel cell described above.

[0020] The present invention provides a liquid hydrogen cooling energy utilization system for fuel cells, which has the following beneficial effects:

[0021] A step-by-step heat exchange cycle is employed. The coolant in the vehicle's auxiliary cooling system, at a lower temperature, serves as the heat medium in the primary heat exchange cycle, exchanging heat with the low-temperature gaseous hydrogen from the liquid hydrogen tank, thereby reducing the vehicle's auxiliary cooling energy consumption. The fuel cell stack exhaust mixed gas heat exchange cycle, at a temperature close to the stack's operating temperature, serves as the heat medium in the secondary heat exchange cycle, exchanging heat with the low-temperature gaseous hydrogen after the primary heat exchange cycle, thereby utilizing the waste heat from the fuel cell exhaust. This simple system effectively and efficiently utilizes liquid hydrogen cooling energy.

[0022] The present invention also provides a fuel cell using the above-mentioned liquid hydrogen cooling energy utilization system, which has the same beneficial effects and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0024] Figure 1 A schematic structural diagram of a primary heat exchange circulation unit provided in a first embodiment of the present invention;

[0025] Figure 2 This is a schematic structural diagram of a liquid hydrogen cooling energy utilization system for a fuel cell provided in a first embodiment of the present invention;

[0026] Figure 3 A schematic structural diagram of a primary heat exchange circulation unit provided in a second specific embodiment of the present invention;

[0027] Figure 4This is a schematic structural diagram of a liquid hydrogen cooling energy utilization system for a fuel cell provided in a second specific embodiment of the present invention.

[0028] In the above picture:

[0029] 100-Liquid hydrogen tank;

[0030] 210 - first heat exchanger; 220 - vehicle auxiliary cooling system; 230 - converter; 231 - coolant inlet; 232 - coolant outlet; 240 - water pump; 250 - thermostat; 260 - three-way valve;

[0031] 310-second heat exchanger; 320-fuel cell stack; 330-exhaust muffler; 340-water separator; 350-vehicle mixed exhaust port; 360-hydrogen circulation pump;

[0032] Q-Air. DETAILED DESCRIPTION

[0033] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0034] In fact, existing technologies also include two ways to utilize liquid hydrogen's cold energy: using cold hydrogen to exchange heat with the fuel cell's intake air, or using cold hydrogen to exchange heat with the fuel cell's cooling cycle subsystem. The first method uses cold hydrogen to lower the temperature of the hydrogen entering the air compressor and the high-pressure, high-temperature air passing through the air compressor, thereby reducing the air compressor's parasitic losses. The second method connects the cold hydrogen heat exchanger to the fuel cell cooling cycle, using the hydrogen's cold energy to reduce the power consumption of the fuel cell radiator, while preheating the hydrogen entering the stack and improving energy utilization efficiency.

[0035] However, both of the above methods have some significant disadvantages. When the temperature of the cold hydrogen is too low, it will have an adverse effect on the performance of the fuel cell. Since it is necessary to connect to the fuel cell's own cooling system, multiple three-way valves are usually required, which will increase the flow resistance of the cooling pipeline, causing the speed of the fuel cell cooling fan to fluctuate, and even affect the stability of the fuel cell's own cooling system. In addition, the fuel cell's own cooling cycle system is highly integrated and is generally directly integrated with the engine. Adding external heat exchangers, valves and other devices will damage the original pipeline, increase the difficulty of design and implementation, and further increase the complexity of the cooling cycle system.

[0036] Based on this, the core of the present invention is to provide a liquid hydrogen cold energy utilization system for fuel cells, which adopts a two-stage heat exchange cycle and uses the heat exchange cycle of the vehicle auxiliary cooling system and the heat exchange cycle of the fuel cell tail exhaust gas to heat up the low-temperature hydrogen. The liquid hydrogen cold energy utilization system has a simple structure and can achieve efficient utilization of liquid hydrogen cold energy.

[0037] Specifically, the present invention provides a liquid hydrogen cold energy utilization system for a fuel cell, comprising a liquid hydrogen tank 100, a primary heat exchange circulation unit, and a secondary heat exchange circulation unit. The primary heat exchange circulation unit is a heat exchange circulation for the vehicle's auxiliary cooling system, primarily comprising a first heat exchanger 210 and the vehicle's auxiliary cooling system 220. The secondary heat exchange circulation unit is a heat exchange circulation for the fuel cell's exhaust gas, primarily comprising a second heat exchanger 310 and a fuel cell stack 320.

[0038] In the primary heat exchange cycle, the outlet of the liquid hydrogen tank 100 is connected to the refrigerant inlet of the first heat exchanger 210, which in turn is connected to the coolant outlet of the vehicle auxiliary cooling system 220. The hydrogen in the liquid hydrogen tank 100 is vaporized and pressurized, converted into low-temperature gaseous hydrogen. This hydrogen enters the refrigerant channel of the first heat exchanger 210 as the refrigerant medium, while the coolant from the vehicle auxiliary cooling system 220 enters the heat channel of the first heat exchanger 210 as the heat medium. The low-temperature gaseous hydrogen in the first heat exchanger 210 absorbs heat from the coolant, undergoing primary heating before entering the secondary heat exchange cycle for heat exchange.

[0039] It should be noted that liquid hydrogen will vaporize rapidly at room temperature, but in liquid hydrogen tanks, in order to control the vaporization rate, insulating materials are usually used to reduce heat transfer. When liquid hydrogen needs to be converted into gaseous hydrogen, the vaporization process can be accelerated by heating or introducing an external heat source. The vaporized hydrogen needs to be pressurized to reach the required operating pressure. This is usually achieved through a hydrogen compressor. The compressor can compress low-pressure gaseous hydrogen to a higher pressure for easy storage and transportation. The hydrogen after vaporization and pressurization is still low-temperature, because the temperature of liquid hydrogen is very low (about -253°C), and even during the vaporization process, the temperature of the hydrogen will not immediately rise to room temperature. Therefore, the vaporized hydrogen is still low-temperature gaseous hydrogen.

[0040] In the secondary heat exchange cycle, the refrigerant outlet of the first heat exchanger 210 is connected to the refrigerant inlet of the second heat exchanger 310, the refrigerant outlet of the second heat exchanger 310 is connected to the hydrogen inlet of the fuel cell stack 320, the gas outlet of the fuel cell stack 320 is connected to the heat medium inlet of the second heat exchanger 310, and the heat medium outlet of the second heat exchanger 310 is connected to the vehicle mixed exhaust port 350. The low-temperature gaseous hydrogen after passing through the first heat exchanger 210 flows into the refrigerant channel of the second heat exchanger 310 as the refrigerant medium. The tail exhaust mixed gas discharged after the reaction of the fuel cell stack 320 passes through the heat medium channel of the second heat exchanger 310 as the heat medium. The low-temperature gaseous hydrogen in the second heat exchanger 310 exchanges heat with the tail exhaust mixed gas of the fuel cell stack 320. After secondary heating, the low-temperature gaseous hydrogen enters the fuel cell stack 320 to react.

[0041] It should be noted that the fuel cell stack 320 has an air inlet and a hydrogen inlet. The air Q and the hydrogen from the refrigerant outlet of the second heat exchanger 310 enter the fuel cell stack 320 to undergo an electrochemical reaction to generate electrical energy. The high-temperature and high-humidity air, nitrogen and a small amount of hydrogen after the reaction are discharged from the gas outlet of the fuel cell stack 320, pass through the heat medium channel of the second heat exchanger 310, and are discharged from the mixed exhaust port 350 of the whole vehicle.

[0042] The present invention provides a liquid hydrogen cold energy utilization system for fuel cells, which adopts a step-by-step heat exchange cycle. In particular, the coolant temperature of the vehicle auxiliary heat dissipation system 220 is relatively low. It serves as the heat medium of the first heat exchange cycle, performing a primary heat exchange on the low-temperature gaseous hydrogen from the liquid hydrogen tank 100, thereby reducing the auxiliary heat dissipation energy consumption of the vehicle. The mixed gas heat exchange cycle temperature of the fuel cell stack 320 is close to the operating temperature of the stack 320. It serves as the heat medium of the second heat exchange cycle, performing a secondary heat exchange on the low-temperature gaseous hydrogen after the first heat exchange cycle, thereby utilizing the waste heat of the fuel cell tail gas. The above system has a simple structure, rationally utilizes liquid hydrogen cold energy, reduces the system's heat dissipation energy consumption, effectively utilizes the waste heat of the fuel cell, and at the same time ensures that the hydrogen meets the temperature requirements for entering the stack, ultimately achieving efficient utilization of liquid hydrogen cold energy.

[0043] Compared with the existing technology, the liquid hydrogen cooling energy utilization system used in this case does not affect the operation of the heat dissipation system of the fuel cell system itself. While protecting the stability of the original heat dissipation system, it realizes the heat exchange and heating of low-temperature hydrogen.

[0044] Converter 230 performs multiple functions within the fuel cell, including voltage regulation, power control, efficiency improvement, and system reliability enhancement. This ensures efficient, stable, and reliable operation of the fuel cell system, playing a key role in the system. Generally, the vehicle's auxiliary cooling system 220 also dissipates heat for converter 230.

[0045] In one embodiment, a portion of the coolant in the vehicle auxiliary cooling system 220 is directly heat-exchanged with the low-temperature gaseous hydrogen in the first heat exchanger 210, while the remaining portion is used to dissipate heat in the converter 230 and ultimately returns to the vehicle auxiliary cooling system 220. In another embodiment, the entire coolant in the vehicle auxiliary cooling system 220 is first heat-exchanged with the low-temperature gaseous hydrogen in the first heat exchanger 210, then used to dissipate heat in the converter 230 and ultimately returns to the vehicle auxiliary cooling system 220.

[0046] In order to enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0047] Example 1

[0048] like Figure 1 and Figure 2 As shown, this embodiment provides a liquid hydrogen cold energy utilization system for a fuel cell, which includes a liquid hydrogen tank 100, a primary heat exchange circulation unit, and a secondary heat exchange circulation unit. The primary heat exchange circulation unit includes a first heat exchanger 210, a vehicle auxiliary cooling system 220, a converter 230, a thermostat 250, and a three-way valve 260. The secondary heat exchange circulation unit includes a second heat exchanger 310 and a fuel cell stack 320.

[0049] The outlet of the liquid hydrogen tank 100 is connected to the refrigerant inlet of the first heat exchanger 210, the inlet of the thermostat 250 is connected to the coolant outlet of the auxiliary cooling system 220 of the whole vehicle, and the two outlets of the thermostat 250 are respectively connected to the heat medium inlet of the first heat exchanger 210 and the coolant inlet 231 of the converter 230; the outlet of the three-way valve 260 is connected to the coolant inlet of the auxiliary cooling system 220 of the whole vehicle, and the two inlets of the three-way valve 260 are respectively connected to the heat medium outlet of the first heat exchanger 210 and the coolant outlet 232 of the converter 230.

[0050] The refrigerant outlet of the first heat exchanger 210 is connected to the refrigerant inlet of the second heat exchanger 310, the refrigerant outlet of the second heat exchanger 310 is connected to the hydrogen inlet of the fuel cell stack 320, the gas outlet of the fuel cell stack 320 is connected to the heat medium inlet of the second heat exchanger 310, and the heat medium outlet of the second heat exchanger 310 is connected to the mixed exhaust port 350 of the whole vehicle.

[0051] The hydrogen in the liquid hydrogen tank 100 is converted into low-temperature gaseous hydrogen after vaporization and pressurization, and then passes through the first heat exchanger 210 to exchange heat with the first-stage heat exchange circulation unit. The first-stage heat exchange circulation unit is cooled by the auxiliary cooling system 220 of the whole vehicle. The coolant from the auxiliary cooling system 220 of the whole vehicle is adjusted by the thermostat 250 to adjust the coolant flow rate to change the heat exchange amount. The thermostat 250 diverts two parts of coolant. One part of the coolant passes through the converter 230 to dissipate heat and then enters the three-way valve 260. The other part of the coolant passes through the first heat exchanger 210 for heat exchange, and merges with the coolant from the converter 230 through the three-way valve 260, and finally returns to the auxiliary cooling system 220 of the whole vehicle.

[0052] It should be noted that thermostat 250 can adjust the coolant flow rate based on the load of the vehicle's auxiliary cooling system 220, reducing auxiliary cooling energy consumption. Furthermore, the primary heat exchange circulation unit has low temperature requirements, preventing the fuel cell's performance from being affected by a low hydrogen temperature causing the primary heat exchange circulation unit to cool. For example, when the thermal load of the vehicle's auxiliary cooling system 220 is excessive or the energy consumption of the vehicle's auxiliary cooling system 220 needs to be reduced, thermostat 250 can be adjusted to increase the coolant flow rate in the pipeline between the primary heat exchange circulation unit and the first heat exchanger 210. The cold energy of the low-temperature gaseous hydrogen can be used to lower the auxiliary cooling circulation coolant temperature, thereby reducing the cooling load of the vehicle's auxiliary cooling system 220.

[0053] The low-temperature gaseous hydrogen after passing through the first heat exchanger 210 flows into the second heat exchanger 310 and exchanges heat with the tail exhaust mixed gas discharged from the fuel cell stack 320 in the second heat exchanger 310. After secondary heating, the low-temperature gaseous hydrogen enters the fuel cell stack 320 for reaction.

[0054] Example 2

[0055] like Figure 3 and Figure 4 As shown, this embodiment provides a liquid hydrogen cold energy utilization system for a fuel cell, which includes a liquid hydrogen tank 100, a primary heat exchange circulation unit and a secondary heat exchange circulation unit. The primary heat exchange circulation unit includes a first heat exchanger 210, a vehicle auxiliary heat dissipation system 220 and a converter 230.

[0056] Among them, the outlet of the liquid hydrogen tank 100 is connected to the refrigerant inlet of the first heat exchanger 210, the heat medium inlet of the first heat exchanger 210 is connected to the coolant outlet of the auxiliary cooling system 220 of the whole vehicle, the heat medium outlet of the first heat exchanger 210 is connected to the coolant inlet 231 of the converter 230, and the coolant outlet 232 of the converter 230 is connected to the coolant inlet of the auxiliary cooling system 220 of the whole vehicle.

[0057] The refrigerant outlet of the first heat exchanger 210 is connected to the refrigerant inlet of the second heat exchanger 310, the refrigerant outlet of the second heat exchanger 310 is connected to the hydrogen inlet of the fuel cell stack 320, the gas outlet of the fuel cell stack 320 is connected to the heat medium inlet of the second heat exchanger 310, and the heat medium outlet of the second heat exchanger 310 is connected to the mixed exhaust port 350 of the whole vehicle.

[0058] Compared with Example 1, the vehicle auxiliary cooling system 220 and the converter 230 of the first-stage heat exchange circulation unit in this embodiment adopt a series mode. The coolant from the vehicle auxiliary cooling system 220 first passes through the first heat exchanger 210 to exchange heat with the low-temperature gaseous hydrogen from the liquid hydrogen tank 100. The coolant after heat exchange is then dissipated through the converter 230 and finally returns to the vehicle auxiliary cooling system 220. This structure eliminates the thermostat and three-way valve in Example 1, and the structure is simpler. However, this structure cannot adjust the heat exchange flow rate, and thus cannot regulate the temperature of the entire auxiliary cooling system. In actual applications, the specific structure of the first-stage heat exchange circulation unit can be selected according to the adaptability to the specific working conditions of the fuel cell, which will not be elaborated here.

[0059] Similarly, the low-temperature gaseous hydrogen after passing through the first heat exchanger 210 flows into the second heat exchanger 310, and exchanges heat with the tail exhaust mixed gas discharged from the fuel cell stack 320 in the second heat exchanger 310. After secondary heating, the low-temperature gaseous hydrogen enters the fuel cell stack 320 for reaction.

[0060] Based on the above-mentioned specific embodiments 1 and 2, the converter 230 mainly includes a DC / DC converter, a DC-AC converter and a Z-source inverter. Specifically, a DC / DC converter can be used to adjust the DC voltage output by the fuel cell, converting the unstable output voltage of the fuel cell into a stable DC voltage to adapt it to the requirements of different loads.

[0061] Furthermore, in order to improve the circulation power, the first-stage heat exchange circulation unit also includes a water pump 240, which is connected in series between the heat medium inlet of the first heat exchanger 210 and the coolant outlet of the vehicle auxiliary cooling system 220.

[0062] Typically, when a proton exchange membrane fuel cell is operating, the reaction gas typically needs to be humidified because the proton exchange membrane needs to maintain a certain water content to improve its ion conductivity. At the same time, liquid water is also generated at the cathode. Therefore, the gas outlet of the fuel cell stack 320 is typically a gas-liquid mixture. To separate excess liquid water from the gas, a water separator 340 is also provided in the secondary heat exchange circulation unit. The air inlet of the water separator 340 is connected to the gas outlet of the fuel cell stack 320, and the gas outlet of the water separator 340 is connected to the heat medium inlet of the second heat exchanger 310.

[0063] The liquid outlet of the water separator 340 is connected to the vehicle mixed discharge outlet 350. The liquid water is separated by the water separator 340 and discharged directly into the vehicle mixed discharge outlet 350. The high-temperature gas flows into the second heat exchanger 310 for secondary heat exchange and is discharged through the vehicle mixed discharge outlet 350.

[0064] To reduce exhaust noise, the secondary heat exchange circulation unit also includes an exhaust muffler 330, which is connected in series between the air inlet of the water separator 340 and the gas outlet of the fuel cell stack 320. Hydrogen and air Q enter the fuel cell stack 320 to undergo an electrochemical reaction, generating electricity. The high-temperature, high-humidity air, nitrogen, and a small amount of hydrogen after the reaction flow into the exhaust muffler 330 of the fuel cell for silencing, and then the liquid water is separated by the water separator 340. After the exhaust gas enters the second heat exchanger 310, it is equivalent to a secondary silencing of the exhaust gas, which can effectively reduce the exhaust noise of the fuel cell system and improve user experience.

[0065] Similarly, in order to improve the circulation power of the secondary heat exchange circulation unit, the secondary heat exchange circulation unit also includes a hydrogen circulation pump 360, which is connected in series between the refrigerant outlet of the second heat exchanger 310 and the hydrogen inlet of the fuel cell stack 320.

[0066] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous technical features can be freely combined and superimposed.

[0067] In addition, the present invention also provides a fuel cell, including a liquid hydrogen cooling energy utilization system for a fuel cell, and the liquid hydrogen cooling energy utilization system for a fuel cell is the liquid hydrogen cooling energy utilization system for a fuel cell in the above-mentioned specific embodiment.

[0068] The beneficial effects brought about by the technical solution provided by the present invention include:

[0069] 1. Establish a heat exchange cycle for the vehicle's auxiliary cooling system, namely a first-level heat exchange cycle unit, which uses liquid hydrogen cooling to reduce the vehicle's auxiliary cooling temperature, share the heat load of the vehicle's auxiliary cooling system, and reduce auxiliary cooling energy consumption;

[0070] 2. Establish a fuel cell tail gas heat exchange cycle, namely a secondary heat exchange cycle unit, to effectively utilize the high-temperature waste heat in the tail gas to increase the temperature of the hydrogen entering the stack and improve the performance of the fuel cell;

[0071] 3. The operation of the liquid hydrogen cooling energy utilization system does not affect the operation of the fuel cell's own cooling system, nor does it affect the stability of the fuel cell system's cooling fan. While utilizing liquid hydrogen cooling energy, it does not impose an additional burden on the fuel cell's own temperature control.

[0072] The above are merely preferred embodiments of the present invention and do not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

[0073] In the description of this application, the meaning of "plurality" is more than two. If there is a description of "first" or "second", it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0074] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0075] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0076] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A liquid hydrogen cooling energy utilization system for a fuel cell, characterized in that: The invention comprises a liquid hydrogen tank (100), a primary heat exchange circulation unit and a secondary heat exchange circulation unit, wherein the primary heat exchange circulation unit comprises a first heat exchanger (210) and a vehicle auxiliary heat dissipation system (220), and the secondary heat exchange circulation unit comprises a second heat exchanger (310) and a fuel cell stack (320); The outlet of the liquid hydrogen tank (100) is communicated with the refrigerant inlet of the first heat exchanger (210), the heat medium inlet of the first heat exchanger (210) is communicated with the coolant outlet of the auxiliary cooling system (220) of the whole vehicle, the heat medium outlet of the first heat exchanger (210) is communicated with the coolant inlet of the auxiliary cooling system (220) of the whole vehicle, the refrigerant outlet of the first heat exchanger (210) is communicated with the refrigerant inlet of the second heat exchanger (310), the refrigerant outlet of the second heat exchanger (310) is communicated with the hydrogen inlet of the fuel cell stack (320), the gas outlet of the fuel cell stack (320) is communicated with the heat medium inlet of the second heat exchanger (310), and the heat medium outlet of the second heat exchanger (310) is communicated with the mixed exhaust port (350) of the whole vehicle.

2. The liquid hydrogen cooling energy utilization system for fuel cells according to claim 1, characterized in that: The primary heat exchange circulation unit further includes a converter (230), a thermostat (250) and a three-way valve (260); The inlet of the thermostat (250) is in communication with the coolant outlet of the vehicle auxiliary cooling system (220), and the two outlets of the thermostat (250) are in communication with the heat medium inlet of the first heat exchanger (210) and the coolant inlet (231) of the converter (230), respectively; The outlet of the three-way valve (260) is communicated with the coolant inlet of the vehicle auxiliary cooling system (220), and the two inlets of the three-way valve (260) are respectively communicated with the heat medium outlet of the first heat exchanger (210) and the coolant outlet (232) of the converter (230).

3. The liquid hydrogen cooling energy utilization system for fuel cells according to claim 1, characterized in that: The primary heat exchange circulation unit further includes a converter (230); The heat medium outlet of the first heat exchanger (210) is in communication with the coolant inlet (231) of the converter (230), and the coolant outlet (232) of the converter (230) is in communication with the coolant inlet of the vehicle auxiliary cooling system (220).

4. The liquid hydrogen cooling energy utilization system for fuel cells according to claim 2 or 3, characterized in that: The converter (230) is a DC / DC converter.

5. The liquid hydrogen cooling energy utilization system for fuel cells according to claim 2 or 3, characterized in that: The primary heat exchange circulation unit further comprises a water pump (240), and the water pump (240) is connected in series between the heat medium inlet of the first heat exchanger (210) and the coolant outlet of the vehicle auxiliary cooling system (220).

6. The liquid hydrogen cooling energy utilization system for fuel cells according to claim 1, characterized in that: The secondary heat exchange circulation unit further includes a water separator (340), the air inlet of the water separator (340) is connected to the gas outlet of the fuel cell stack (320), and the gas outlet of the water separator (340) is connected to the heat medium inlet of the second heat exchanger (310).

7. The liquid hydrogen cooling energy utilization system for fuel cells according to claim 6, characterized in that: The liquid outlet of the water separator (340) is in communication with the whole vehicle mixed discharge outlet (350).

8. The liquid hydrogen cooling energy utilization system for fuel cells according to claim 6, characterized in that: The secondary heat exchange circulation unit further includes an exhaust gas muffler (330), which is connected in series between the air inlet of the water separator (340) and the gas outlet of the fuel cell stack (320).

9. The liquid hydrogen cooling energy utilization system for fuel cells according to claim 1, characterized in that: The secondary heat exchange circulation unit further includes a hydrogen circulation pump (360), which is connected in series between the refrigerant outlet of the second heat exchanger (310) and the hydrogen inlet of the fuel cell stack (320).

10. A fuel cell, characterized in that: A liquid hydrogen cooling energy utilization system for a fuel cell comprising the liquid hydrogen cooling energy utilization system according to any one of claims 1 to 9.

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