Heat circulation system and method of fuel cell, fuel cell system and vehicle

Abstract

The invention relates to a heat circulation system of a fuel cell, a heat circulation method, a fuel cell system and a vehicle. The system comprises a galvanic pile, and the galvanic pile comprises a galvanic pile inlet end, a galvanic pile outlet end, a circulating medium outlet end and a circulating medium inlet end; the heater is connected with the inlet end of the electric pile and comprises a gas inlet, a gas outlet, a heating medium inlet and a heating medium outlet; the mixer is used for mixing the input gas and comprises a mixer outlet connected with the gas inlet of the heater; and the heat circulation loop comprises an electric pile, a circulation medium outlet end, a circulation medium output pipeline, a heater, a circulation medium input pipeline and a circulation medium inlet end. According to the scheme provided by the embodiment of the invention, the heat generated by the fuel cell is effectively utilized to heat the to-be-reacted gas at the inlet end of the electric pile, so that the liquid water content in the to-be-reacted gas is reduced, the electric pile performance can be improved while the volume of the fuel cell is not obviously increased, and the heat efficiency of the whole system is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of fuel cell systems, and more particularly to a heat circulation system for a fuel cell, a heat circulation method, a fuel cell system, and a vehicle. Background Art

[0002] A fuel cell system is a system that generates electrical energy through the chemical reaction of anode hydrogen gas and cathode oxygen-containing gas. It has the advantages of high energy conversion efficiency and pollution-free emissions, and has important applications in many fields. For example, in the field of new energy vehicles, proton exchange membrane fuel cells fueled by hydrogen have become a type of widely used automotive power battery.

[0003] For a proton exchange membrane fuel cell, when the fuel cell is actually operating, the anode hydrogen gas cannot fully react with the cathode oxygen-containing gas, and a considerable amount of unreacted residual hydrogen gas remains inside the fuel cell stack. In order to achieve efficient utilization of hydrogen, a hydrogen circulation pump can recover the unreacted hydrogen gas in the stack, pressurize the recovered anode exhaust gas containing hydrogen and nitrogen, and re-introduce it into the fuel cell stack to participate in the electrochemical reaction. Summary of the Invention

[0004] Embodiments of the present disclosure provide a heat circulation system for a fuel cell, a heat circulation method for a fuel cell, a fuel cell system, and a vehicle. In the embodiments of the present disclosure, by providing a heater between the mixer and the inlet end of the stack and introducing the heat generated inside the stack into the heater, the heat generated by the fuel cell itself is effectively utilized to heat the gas to be reacted input at the inlet end of the stack, thereby reducing the liquid water content in the gas to be reacted at the inlet of the stack. Furthermore, without significantly increasing the volume of the fuel cell and the complexity of the fuel cell system, the performance of the stack can be improved, and the thermal efficiency of the entire system can be increased.

[0005] In a first aspect of the present disclosure, a heat circulation system for a fuel cell is provided, including a stack, the stack including an inlet end of the stack, an outlet end of the stack, an outlet end of the circulating medium, and an inlet end of the circulating medium; a heater, the heater being coupled to the inlet end of the stack, the heater including a gas inlet for inputting gas, a gas outlet for outputting gas to the inlet end of the stack, a heating medium inlet coupled to the outlet end of the circulating medium, and a heating medium outlet coupled to the inlet end of the circulating medium; a mixer, including a mixer outlet coupled to the gas inlet of the heater, the mixer being configured to mix the input gas; and a heat circulation loop, including the stack, the outlet end of the circulating medium, a circulating medium output pipeline coupled between the outlet end of the circulating medium and the heating medium inlet, the heater, a circulating medium input pipeline coupled between the inlet end of the circulating medium and the heating medium outlet, and the inlet end of the circulating medium.

[0006] In a second aspect of the present disclosure, a heat circulation method for a fuel cell is provided, including providing a heater, which is coupled to an inlet end of a fuel cell stack and includes a gas inlet for inputting gas, a gas outlet for outputting gas to the inlet of the fuel cell stack, a heating medium inlet coupled to an outlet end of a circulation medium of the fuel cell stack, and a heating medium outlet coupled to an inlet end of the circulation medium of the fuel cell stack; providing a mixer, which includes a mixer outlet coupled to the gas inlet of the heater, and the mixer is configured to mix the input gas; and providing a heat circulation loop, including a fuel cell stack, an outlet end of the circulation medium, a circulation medium output pipeline coupled between the outlet end of the circulation medium and the heating medium inlet, the heater, a circulation medium input pipeline coupled between the inlet end of the circulation medium and the heating medium outlet, and an inlet end of the circulation medium.

[0007] In a third aspect of the present disclosure, a fuel cell system is provided, including a heat circulation system of a fuel cell provided according to any of the foregoing aspects.

[0008] In a fourth aspect of the present disclosure, a vehicle is provided, including a fuel cell system provided according to the third aspect of the present disclosure.

[0009] It should be understood that the content described in the summary of the invention section is not intended to limit the key or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In combination with the accompanying drawings and with reference to the following detailed description, the above and other features, advantages and aspects of the embodiments of the present disclosure will become more obvious. In the drawings, the same or similar reference numerals denote the same or similar elements, where:

[0011] Figure 1 A schematic diagram of a fuel cell system in which multiple embodiments of the present disclosure can be implemented is shown;

[0012] Figure 2 A schematic diagram of a heat circulation system of a fuel cell according to some embodiments of the present disclosure is shown;

[0013] Figure 3 A schematic diagram of a heat circulation system of a fuel cell according to other embodiments of the present disclosure is shown;

[0014] Figure 4 A schematic diagram of a circulation process during the operation of a fuel cell stack based on a heat circulation system of the fuel cell according to some embodiments of the present disclosure is shown;

[0015] Figure 5Shows a schematic diagram of a heater according to some embodiments of the present disclosure;

[0016] Figure 6 Shows a cross-sectional schematic diagram of a heater according to some embodiments of the present disclosure;

[0017] Figure 7 Shows a cross-sectional schematic diagram of a heater according to some other embodiments of the present disclosure;

[0018] Figure 8 Shows a flowchart of a heat circulation method according to some embodiments of the present disclosure. Detailed Description of Specific Embodiments

[0019] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not used to limit the protection scope of the present disclosure. The embodiments of the present disclosure described below with reference to the accompanying drawings are only for exemplary purposes.

[0020] In the description of the embodiments of the present disclosure, the term "including" and its like should be understood as an open inclusion, that is, "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects. There may also be other explicit and implicit definitions below.

[0021] The inventors of the present disclosure have found that during the operation of a fuel cell, when using a hydrogen circulation pump to circulate the gas at the exhaust gas outlet of the stack, since the gas in the exhaust gas circulation loop contains components such as hydrogen, nitrogen, and water vapor, and the hydrogen injected from the hydrogen gas injector (HGI) has a lower temperature, after the gas in the anode circulation loop is mixed with the hydrogen injected from the HGI in the intake pipeline, the temperature of the mixed gas before entering the inlet end of the stack is lower than the temperature at the outlet end of the stack. The temperature reduction causes a part of the water vapor in the mixed gas to condense and become liquid water. However, if this liquid water enters the stack through the inlet end of the stack along with the mixed gas, it will cause the stack to be flooded, thereby affecting the performance and lifespan of the stack. How to improve the performance and service life of the stack without increasing the complexity of the entire system is an urgent problem to be solved currently.

[0022] During the operation of a fuel cell system, in order to improve the performance and service life of the fuel cell stack while minimizing the increase in the complexity of the fuel cell system, the present disclosure proposes a heat circulation system for a fuel cell, a heat circulation method for a fuel cell, a fuel cell system, and a vehicle. A heat circulation system for a fuel cell proposed in an embodiment of the present disclosure includes a fuel cell stack, which includes a fuel cell stack inlet end, a fuel cell stack outlet end, a circulating medium outlet end, and a circulating medium inlet end. It further includes a heater connected to the fuel cell stack inlet end. The heater includes a gas inlet for inputting gas, a gas outlet for outputting the gas to the fuel cell stack inlet end, a heating medium inlet connected to the circulating medium outlet end, and a heating medium outlet connected to the circulating medium inlet end. The system further includes a mixer for mixing the gas input to the mixer, and the mixer has a mixer outlet connected to the gas inlet of the heater. The system further includes a heat circulation loop, which specifically includes a fuel cell stack, a circulating medium outlet end, a circulating medium output pipeline connected between the circulating medium outlet end and the heating medium inlet, a heater, a circulating medium input pipeline connected between the circulating medium inlet end and the heating medium outlet, and a circulating medium inlet end. The solution of the present disclosure can effectively utilize the heat generated by the fuel cell itself to heat the gas to be reacted input to the fuel cell stack inlet end by setting a heater between the mixer and the fuel cell stack inlet end and introducing the heat generated inside the fuel cell stack into the heater, thereby reducing the liquid water content in the gas to be reacted at the fuel cell stack inlet. The solution of the present disclosure can improve the performance of the fuel cell stack and the thermal efficiency of the entire system while not significantly increasing the volume of the fuel cell and the complexity of the fuel cell system.

[0023] Figure 1 FIG. shows a schematic diagram of an exemplary fuel cell system 100 in which multiple embodiments of the present disclosure can be implemented. Figure 1 Taking the structure of a typical fuel cell system as an example, it can be used as an exemplary structure of a fuel cell system without limiting the technical solutions of the present disclosure. As Figure 1 shown, in the fuel cell system 100, it includes an anode chamber 106, a membrane electrode 107, and a cathode chamber 105. The membrane electrode 107 in the form of a semi-permeable membrane is located between the anode chamber 106 and the cathode chamber 105 and is used to conduct protons and isolate the reactants in the anode chamber 106 and the cathode chamber 105. The anode chamber 106, the membrane electrode 107, and the cathode chamber 105 together form a fuel cell. Hydrogen in the anode chamber 106 and oxygen-containing gas in the cathode chamber 105 undergo a chemical reaction on the membrane electrode 107, thereby generating an electric current, which can be supplied to other devices through an electric energy converter 108, such as powering the motor of a vehicle, charging the vehicle battery, etc.

[0024] In some embodiments, the fuel cell system 100 further includes an anode inlet 103 and an anode outlet 104 coupled to the anode circuit, and a cathode inlet 101 and a cathode outlet 102 coupled to the cathode circuit, which together with the anode chamber 106, the membrane electrode 107, and the cathode chamber 105 form the fuel cell system. The anode circuit is used to supply hydrogen gas to the anode 106. The hydrogen gas flows into the anode chamber 106 from the anode inlet 103. The cathode circuit can supply an oxygen-containing gas such as air to the cathode chamber 105. The hydrogen gas and the oxygen in the air can undergo a chemical reaction at the membrane electrode 107. The remaining unreacted hydrogen gas can be discharged through the anode outlet 104 and enter the anode circulation circuit 109. It should be understood that Figure 1 The illustrated fuel cell system 100 is merely an example of the embodiments of the present disclosure and is not a limitation on the present disclosure.

[0025] Figure 2 FIG. shows a schematic diagram of a heat circulation system of a fuel cell according to some embodiments of the present disclosure. The heat circulation system 200 of the fuel cell includes a stack 201. The stack 201 includes a stack inlet end 202 for inputting a mixed gas, a stack outlet end 203 for outputting exhaust gas, a circulation medium outlet end 204 for the outflow of the circulation medium, and a circulation medium inlet end 205 for the inflow of the circulation medium. The exhaust gas output from the stack outlet end 203 is transported to the stack inlet end 202 through the hydrogen circulation loop. In some embodiments, the circulation medium is a cooling substance with a relatively large specific heat capacity such as cooling water or Freon. The present disclosure does not limit this. The present disclosure will be described by taking cooling water as an example.

[0026] In some embodiments, the heat circulation system 200 further includes a mixer 220 for mixing the input gases. The mixer 220 includes a first mixer inlet 221, a second mixer inlet 223, and a mixer outlet 222. The first mixer inlet 221 is connected to the air inlet of the fuel cell system for receiving the hydrogen gas injected by the HGI at the air inlet of the fuel cell system. The second mixer inlet 223 is connected to the hydrogen circulation pipeline 224 for receiving the anode circulation exhaust gas. The mixer 220 can mix the input anode circulation exhaust gas and the hydrogen gas injected by the HGI and output from the mixer outlet 222. In some embodiments, the mixed gas is input into a compression device such as a compressor for compression and then output. In some embodiments, the mixer 220 also has a compression function. The mixer 220 can mix and compress the input anode circulation exhaust gas and the hydrogen gas injected by the HGI and then output from the mixer outlet 222. In some embodiments, the mixer 220 can be an ejector 220. The ejector 220 includes an ejector outlet 222. The ejector outlet 222 is connected to the gas inlet 211 of the heater 210, so as to mix and compress the input multiple paths of gases and then output from the ejector outlet 222.

[0027] In some embodiments, as Figure 2 shown in the embodiments, the mixed gas output from the ejector outlet 222 is a mixture, including the anode exhaust gas containing nitrogen and water vapor, and the hydrogen gas injected from the HGI. The heat cycle system 200 further includes a heater 210 for heating the mixed gas. The heater 210 is connected between the mixer 220 and the fuel cell stack inlet end 202. The heater 210 includes a gas inlet 211, a gas outlet 212, a heating medium inlet 208, and a heating medium outlet 209. The gas inlet 211 is connected to the mixer outlet 222 for inputting the mixed gas. The gas outlet 212 is connected to the fuel cell stack inlet end 202 for outputting the heated mixed gas to the fuel cell stack inlet end 202. The heating medium inlet 208 is connected to the circulating medium outlet end 204 through the circulating medium output pipeline 206 for the inflow of cooling water. The heating medium outlet 209 is connected to the circulating medium inlet end 205 through the circulating medium input pipeline 207 for the outflow of cooling water. Thus, the exhaust gas containing hydrogen output from the fuel cell stack outlet end 203 is sequentially conveyed to the fuel cell stack inlet end 202 after passing through the ejector 220 and the heater 210.

[0028] In some embodiments, the heater 210 can be divided into at least two parts, for example, including a first pipe and a second pipe. The first pipe is for the passage of the mixed gas, and the second pipe is for the passage of the cooling water. According to different heat exchange requirements of the system, the mixed gas and the cooling water can be designed to pass through the heater 210 in the same direction or in the opposite direction. As Figure 5 shown are some embodiments where the heater has concentric double-layer pipes and the mixed gas and the cooling water pass through the heater in the opposite direction.

[0029] In some embodiments, a heat circulation loop L1 is provided in the heat circulation system 200. The heat circulation loop L1 includes a fuel cell stack 201, a circulating medium outlet end 204, a circulating medium output pipeline 206, a heater 210, a circulating medium input pipeline 207, and a circulating medium inlet end 205. The heat generated by the reaction occurring inside the fuel cell stack 201 is transferred to the cooling water, and the temperature of the cooling water rises and is output from the circulating medium outlet end 204. It passes through the cooling medium output pipeline 206 and enters the heater 210 from the heating medium inlet 208. The cooling water flowing in the heater 210 heats the mixed gas in the gas pipeline of the heater 210, and then flows out from the heating medium outlet 209, passes through the cooling medium input pipeline 207, and returns to the circulating medium inlet end 205, thus forming the first heat circulation loop L1. Since the cooling water entering the heater from the heating medium inlet 208 exchanges heat with the mixed gas, the temperature of the cooling water at the heating medium outlet 209 is lower than that at the heating medium inlet 208, that is, the temperature of the cooling water at the circulating medium inlet end 205 is lower than that at the circulating medium outlet end 204. Thus, by providing the circulating medium output pipeline 206 between the circulating medium outlet end 204 and the heating medium inlet 208, the heat generated by the fuel cell stack can be led back to the heater 210 near the fuel cell stack inlet end 202. After the input gas to be input to the fuel cell stack inlet end 202 is heated by the heater 210, it is then input to the fuel cell stack inlet end 202, thereby reducing the content of condensed water in the gas to be reacted at the fuel cell stack inlet and improving the performance of the fuel cell stack. At the same time, a circulating medium input pipeline 207 is provided between the circulating medium inlet end 205 and the heating medium outlet 209, and then the lower-temperature cooling water is conveyed back into the fuel cell stack 201 again to cool the fuel cell stack 201. Repeating this process, the technical solution of the present disclosure can improve the performance of the fuel cell stack while not significantly increasing the volume of the fuel cell and the complexity of the fuel cell system, and can effectively utilize the energy in the waste gas.

[0030] In some embodiments, such as Figure 2The fuel cell stack 201 shown in [description] includes a cathode chamber and an anode chamber. The stack inlet end 202 and the stack outlet end 204 can be provided in the cathode chamber or the anode chamber, and the present disclosure does not limit this. In this embodiment, the case where the anode chamber includes the stack inlet end 202 and the stack outlet end 204 is taken as an example for illustration. The gas at the inlet of the fuel cell system 200 is hydrogen or other gases that can undergo an electrochemical reaction, and the present disclosure does not limit this. According to needs, the heat circulation system 200 of the fuel cell may further include other components not shown, such as pressure sensors, temperature sensors, humidity sensors, etc., and the present disclosure does not limit this. In the embodiments of the present disclosure, by providing a heater between the mixer and the stack inlet end, the content of liquid water in the gas to be reacted at the stack inlet is reduced, the performance of the stack is improved, and accordingly, the service life of the stack can be extended, and at the same time, the volume of the fuel cell and the complexity of the fuel cell system are not significantly increased. In the embodiments of the present disclosure, by introducing the heat generated inside the stack into the heater, the heat generated by the fuel cell itself can also be effectively utilized to heat the gas to be reacted input at the stack inlet end; on the other hand, the lower-temperature mixed gas cools the higher-temperature cooling water at the stack outlet end, thereby improving the thermal efficiency of the entire system and further enhancing the performance of the stack.

[0031] Figure 3 The schematic diagram of the heat circulation system 300 of a fuel cell according to some other embodiments of the present disclosure is shown to correspond to Figure 2Embodiments will be described. In some embodiments, the heat circulation loop of the heat circulation system 300 of the fuel cell further includes a second heat circulation loop L2. The stack 301, the circulation medium outlet end 304, the cooling medium output pipeline 316, and the circulation medium inlet end 305 form the second heat circulation loop L2. In the second heat circulation loop L2, a radiator 315 is further included. The radiator 315 is connected between the circulation medium outlet end 304 and the circulation medium inlet end 305 and is used to dissipate heat from the relatively high-temperature cooling water flowing out of the stack 301. At this time, the stack 301, the circulation medium outlet end 304, the circulation medium output pipeline 316, the radiator 315, the circulation medium input pipeline 317, and the circulation medium inlet end 305 form the second heat circulation loop L2. During actual operation, the heat generated by the reaction inside the stack 301 is transferred to the cooling water inside the stack, so that the temperature of the cooling water rises. The relatively high-temperature cooling water output from the circulation medium outlet end 304 enters the radiator 315 through the circulation medium output pipeline 316 and is cooled. The temperature of the cooling water decreases, and the relatively low-temperature cooling water then enters the circulation medium inlet end 305 through the circulation medium input pipeline 317, so that the relatively low-temperature cooling water after heat dissipation can return to the stack 301 again to cool the stack 301, and so on. In some embodiments, in order to improve the performance of the stack, a circulation pump 318 can be provided in the circulation medium pipeline to increase the circulation speed of the cooling water in the cooling medium output pipeline 316 and the cooling medium input pipeline 317, thereby improving the heat dissipation efficiency of the relatively high-temperature cooling water.

[0032] Therefore, in the heat circulation system 300 of the fuel cell of the present disclosure, after the cooling water in the pipeline of the first heat circulation loop L1 exchanges heat with the mixed gas in the heater 310, the temperature of the cooling water in the circulation medium output pipeline 307 will decrease. When there is a shared pipeline between the circulation medium first output pipeline 306 and the circulation medium second output pipeline 316, and there is a shared pipeline between the circulation medium first input pipeline 307 and the circulation medium first input pipeline 317, the temperature of the cooling water in the pipeline of the second heat circulation loop L2 will be affected by the temperature of the cooling water in the pipeline of the first heat circulation loop L1. Therefore, the second heat circulation loop L2 can also reduce the power consumption of the radiator 315 and the circulation pump 318 in the first heat circulation loop L1, thereby reducing the working energy consumption of the fuel cell system.

[0033] In some embodiments, the temperature and humidity of the mixed gas, the temperature and flow rate of the cooling water, the flow velocity, etc. are all related to the amount of heat that can be exchanged. Therefore, in the technical solution of the present disclosure, based on the temperature, flow rate, flow velocity, etc. of the cooling water and the target temperature and humidity of the mixed gas to be achieved, the heat demand of the mixed gas can be calculated or simulated, so that the model, specifications of the heater, such as pipe diameter, length, specific structure, etc. can be customized, and then the cooling water can heat the mixed gas to meet the requirements of the fuel cell stack. Considering that the fuel cell system will operate in different stages or working conditions, and at this time the heat demand of different mixed gases will also change, therefore, the present disclosure can also be provided with a mass flow controller in the circulating medium pipeline to achieve flexible control and adjustment of the cooling water. In some embodiments, the first heat circulation loop L1 may include a mass flow controller V31, and the second heat circulation loop L2 may include a mass flow controller V32. The mass flow controllers V31 and V32 can be used to adjust the mass flow in the corresponding loop. In some embodiments, considering actual situations such as heat loss and calculation errors, the present disclosure can also circulate the cooling water to the heater in such a way that the actually supplied cooling water capacity is greater than the theoretical heat demand of the mixed gas calculated or simulated, so as to ensure the heating effect as much as possible and ensure that the heat provided by the cooling water can meet the requirements of the fuel cell stack for the mixed gas.

[0034] Figure 4 FIG. shows a schematic diagram of the circulation process during the operation of the fuel cell stack of the heat circulation system based on the fuel cell according to some embodiments of the present disclosure, corresponding to Figure 3 the embodiments are described. After the electrochemical reaction occurs inside the fuel cell stack of the fuel cell, the generated water needs to be discharged from the fuel cell stack outlet end 403. Therefore, the heat circulation system 400 may include a second water separator 426, connected to the fuel cell stack outlet end 403, for separating the liquid water in the exhaust gas output from the fuel cell stack outlet end 403. In some embodiments, after the heater 410 heats the mixed gas in the intake pipeline, there will still be liquid water that has not completely turned into water vapor in the mixed gas output from the heater outlet 412. Therefore, the heat circulation system 400 of the fuel cell of the present disclosure further includes a first water separator 425, connected between the heater 410 and the fuel cell stack inlet end 402, for separating the liquid water in the mixed gas output from the gas outlet 412 of the heater 410. The liquid water separated by the first water separator 425 can be directly discharged outside the fuel cell system. In some embodiments, the first water separator 425 is led to the second water separator 426, so that in the fuel cell system, the first water separator 425 and the second water separator 426 can share a water outlet, thereby simplifying the system design.

[0035] In some embodiments, during the actual operation of the fuel cell, the capacity of the liquid water separated in the first water separator 425 will change. When there is a large amount of liquid water in the first water separator 425, it is necessary to drain the liquid water in the first water separator 425. In the present disclosure, taking the example of leading the liquid water in the first water separator 425 to the second water separator 426 for illustration. When there is less liquid water in the first water separator 425, due to the pressure difference effect, the mixed gas in the intake pipeline may enter the second water separator 426 from the intake pipeline along the drainage pipeline between the first water separator 425 and the second water separator 426. Therefore, in some embodiments, the present disclosure also designs a mass flow controller V44. The first water separator 425 is led to the second water separator 426 through the mass flow controller V44. Thus, the technical solution of the present disclosure can flexibly control the mass flow controller V44 according to the capacity of the liquid water in the first water separator 425, which can not only ensure that the liquid water in the mixed gas can be discharged in time, but also not affect the utilization rate of hydrogen. Therefore, in the embodiments of the present disclosure, by introducing the first water separator 425 at the inlet end 402 of the fuel cell stack, the remaining liquid water in the heater 410 can be separated and discharged, further reducing the amount of liquid water entering the fuel cell stack 401 through the inlet end 402 of the fuel cell stack, thereby improving the performance of the fuel cell stack. At the same time, in the embodiments of the present disclosure, by setting the mass flow controller V44 between the first water separator 425 and the second water separator 426, it is possible to maximally avoid the hydrogen in the anode intake pipeline from entering the drainage pipeline, thereby ensuring the system safety and ensuring the hydrogen utilization rate.

[0036] In some embodiments, as needed, the heat circulation system 400 of the fuel cell may further include other components not shown, such as various sensors, gas compression devices, control valves, etc. The present disclosure does not limit this. The fuel cell stack 401 is a closed system. In some embodiments, in order to ensure the full reaction of the anode hydrogen and the cathode air and improve the service life of the fuel cell stack, a filter F40 may also be provided at the anode intake port of the fuel cell system for filtering the input hydrogen. The filter F40 is connected to the first inlet 421 of the mixer, and may also be connected to the first inlet 421 of the mixer through a control valve and a hydrogen emitter.

[0037] In the embodiments of the present disclosure, the physical quantities are only given schematically and cannot limit the embodiments of the present disclosure. For example, the heat of the circulating medium may include the energy of heat exchange between the circulating medium and other substances, the temperature of the circulating medium, etc.

[0038] In some embodiments, mass flow controllers may be provided in the intake pipeline, exhaust pipeline, first heat circulation loop L1, and second heat circulation loop L2 to adjust the mass flow in the corresponding pipelines. For example, it may be implemented as a valve or a similar device with an adjustment function. As Figure 4Among them, V41 is arranged in the hydrogen inlet pipeline. By opening or closing the valve V41, the opening, partial opening or closing of the hydrogen flow is realized, so as to realize different hydrogen mass flow rates and pressures required, and convey the hydrogen mass flow meeting the requirements of the fuel cell stack 401 to the fuel cell stack 401 or not convey it to the fuel cell stack 401. V42 and V43 are arranged in the exhaust pipeline of the fuel cell stack. By opening, partially opening or closing the valve V42, the timely discharge of the anode exhaust gas is realized, and then the hydrogen concentration, humidity, temperature, pressure, etc. in the inlet pipeline are adjusted; by fully opening, partially opening or closing the valve V43, the discharge of the liquid water at the outlet end of the fuel cell stack is realized. The mass flow controller can be realized by a two-position three-way valve, or can be an independent valve device arranged in the air pipeline, and can be set as the same valve or different valves. The present disclosure does not limit this. In some embodiments, a valve can be arranged in the hydrogen circulation loop, so as to flexibly distribute the exhaust gas mass flow rate in the circulation loop and the hydrogen concentration, humidity, temperature, pressure, etc. in the inlet pipeline, so as to adjust the total hydrogen flow rate, pressure, temperature, humidity, etc. entering the fuel cell stack 401 to meet the requirements. In the embodiments of the present disclosure, the mass flow can include the volume, mass, or amount of substance of the gas, etc., which is only given schematically and cannot be a limitation to the embodiments of the present disclosure.

[0039] In some embodiments, the heat circulation system of the fuel cell further includes a pressure sensor for sensing the pressures of the inlet pipeline, the exhaust pipeline, the first heat circulation loop, the second heat circulation loop, and the cathode chamber and the anode chamber in the fuel cell stack. The heat circulation system of the fuel cell may further include a humidity sensor for sensing the humidities of the inlet pipeline, the exhaust pipeline, the first heat circulation loop, the second heat circulation loop, and the cathode chamber and the anode chamber in the fuel cell stack. In addition, a temperature sensor can be arranged for sensing the temperatures of the inlet pipeline, the exhaust pipeline, the first heat circulation loop, the second heat circulation loop, and the cathode chamber and the anode chamber in the fuel cell stack. The heat circulation system of the fuel cell in the embodiments of the present disclosure can be used in a fuel cell system, and the fuel cell system can also be other types of fuel cell systems. The present disclosure does not limit this. The fuel cell system in the embodiments of the present disclosure can not only be used in new energy battery vehicles to provide an energy source for the vehicle, but also be used in other scenarios that require energy supply, such as petrochemical industry, etc. The present disclosure does not limit this.

[0040] As Figure 5A schematic diagram of a heater according to some embodiments of the present disclosure is shown. In some embodiments, the heater 510 includes an inner tube 502 and an outer tube 501, wherein the inner tube 502 is for the mixed gas to pass through, and the gas inlet 511 and the gas outlet 512 are in communication with the inner tube 502. The outer tube 501 is for the cooling water to pass through. The relatively high-temperature cooling water enters the outer tube 501 from the heating medium inlet 508, flows through the outer tube 501 in a direction opposite to the flow direction of the mixed gas, and flows out from the heating medium outlet 509 and enters the circulating medium input pipeline connected to the heating medium outlet 509. Figure 6 shows a cross-sectional schematic diagram of a heater according to some embodiments of the present disclosure corresponding to Figure 5 The specific implementation manners of the first tube and the second tube of the heater 210 are not limited thereto. For example Figure 7 A cross-sectional schematic diagram of a heater according to some other embodiments of the present disclosure is shown. The heater 700 includes a first tube 701 and a second tube 702, wherein the gas inlet and the gas outlet 212 are in communication with the first tube 701, and the heating medium inlet 208 and the heating medium outlet 209 are in communication with the second tube 702. Therefore, the heater of the present disclosure can flexibly implement the heat exchange between the cooling water and the mixed gas, so as to more fully and efficiently heat the gas to be reacted at the inlet of the fuel cell stack, reduce the liquid water content in the gas to be reacted at the inlet of the fuel cell stack, and further improve the working efficiency of the fuel cell system.

[0041] Figure 8 A flowchart of a heat circulation method 800 of a fuel cell according to some embodiments of the present disclosure is shown. In some embodiments, the heat circulation method of the fuel cell includes the following steps: In block 802, the method 800 provides a heater, which is connected to the inlet end of the fuel cell stack of the fuel cell stack, and the heater includes a gas inlet for inputting gas, a gas outlet for outputting gas to the inlet of the fuel cell stack, a heating medium inlet connected to the circulating medium outlet end of the fuel cell stack, and a heating medium outlet connected to the circulating medium inlet end of the fuel cell stack. In block 804, the method 800 provides a mixer for mixing the input gas, the mixer includes a mixer inlet and a mixer outlet, and the mixer outlet is connected to the gas inlet of the heater. In block 806, the method 800 provides a heat circulation loop, which includes a fuel cell stack, a circulating medium outlet end, a circulating medium output pipeline connected between the circulating medium outlet end and the heating medium inlet, a heater, a circulating medium input pipeline connected between the circulating medium inlet end and the heating medium outlet, and a circulating medium inlet end. The heat circulation method of the fuel cell in this embodiment will be based on Figure 2The heat circulation system 200 shown is taken as an example for illustration. In some embodiments, first, a heater 210 is provided. The heater 210 is connected to the stack inlet end 202 of the fuel cell stack 201. And the heater 210 includes a gas inlet 211 for inputting gas, a gas outlet 212 for outputting the gas to the stack inlet end 202, a heating medium inlet 208 connected to the circulation medium outlet end 204 of the fuel cell stack 201, and a heating medium outlet 209 connected to the circulation medium inlet end 205 of the fuel cell stack 201. Then, the method 800 provides a mixer 220 for mixing the input gas. The mixer 220 includes a mixer inlet and a mixer outlet 222. The mixer outlet 222 is connected to the gas inlet 211 of the heater 210. Further, the method 800 provides a heat circulation loop L1. The heat circulation loop L1 includes the fuel cell stack 201, the circulation medium outlet end 204, a circulation medium output pipeline 206 connected between the circulation medium outlet end 204 and the heating medium inlet 208, the heater 210, a circulation medium input pipeline 207 connected between the circulation medium inlet end 205 and the heating medium outlet 209, and the circulation medium inlet end 205. After the cooling water is heated by the fuel cell stack 201 inside the fuel cell stack 201, it flows out from the circulation medium outlet end 204 and flows into the heater 210 through the circulation medium output pipeline 206. After the cooling water exchanges heat with the gas at a lower temperature in the heater 210, the temperature of the cooling water decreases. The cooled cooling water flows out from the heating medium outlet 209 of the heater 210, passes through the circulation medium input pipeline 207, and flows into the fuel cell stack 201 through the circulation medium inlet end 205. In the embodiments of the present disclosure, without significantly increasing the volume of the fuel cell and the complexity of the fuel cell system, the reuse of the heat inside the fuel cell stack is achieved, the performance of the fuel cell stack is improved, and the service life of the fuel cell stack is extended..

[0042] According to the embodiments of the present disclosure, by using the heat generated by the fuel cell itself to heat the gas to be reacted input at the stack inlet end, the content of liquid water in the gas to be reacted at the stack inlet is reduced. Not only can the volume of the fuel cell and the complexity of the fuel cell system not be significantly increased, but also the performance of the fuel cell stack can be improved, and accordingly the service life of the fuel cell stack is extended. At the same time, the thermal efficiency of the whole system can also be improved. On the other hand, the embodiments of the present disclosure can separate and discharge the remaining liquid water in the heater, further reducing the amount of liquid water entering the fuel cell stack through the stack inlet end. This can not only further improve the performance of the fuel cell stack, but also prevent hydrogen in the anode inlet pipeline from entering the drainage pipeline, thus ensuring system safety and ensuring hydrogen utilization rate.

[0043] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. The program code for implementing the methods of the present disclosure can be written in any combination of one or more programming languages. In the context of the present disclosure, although the operations are depicted in a particular order, this should be understood as requiring that the operations be performed in the particular order shown or in a sequential order, or that all of the illustrated operations should be performed to achieve the desired result. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although a number of specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the present disclosure. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single implementation. Conversely, the various features that are described in the context of a single implementation can also be implemented separately or in any suitable sub-combination in multiple implementations.

[0044] Although the subject matter has been described in language specific to structural features and / or methodological logical acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are merely example forms for implementing the claims.

Claims

1. A heat circulation system (200, 300, 400) for a fuel cell, comprising: A stack (201, 301, 401), including a stack inlet end (202, 302, 402), a stack outlet end (203, 303, 403), a circulating medium outlet end (204, 304, 404), and a circulating medium inlet end (205, 305, 405); A heater (210, 310, 410, 510, 600, 700), coupled to the stack inlet end (202, 302, 402), including a gas inlet (211, 311, 411, 511) for inputting gas, a gas outlet (212, 312, 412, 512) for outputting gas to the stack inlet end (202, 302, 402), a heating medium inlet (208, 308, 408, 508) coupled to the circulating medium outlet end (204, 304, 404), and a heating medium outlet (209, 309, 409, 509) coupled to the circulating medium inlet end (205, 305, 405); A mixer (220, 320, 420), including a mixer outlet (222, 322, 422), the mixer outlet (222, 322, 422) being coupled to the gas inlet (211, 311, 411, 511) of the heater (210, 310, 410, 510, 600, 700), the mixer (220, 320, 420) being configured to mix the input gas; A heat circulation loop, including the stack (201, 301, 401), the circulating medium outlet end (204, 304, 404), a circulating medium output pipeline coupled between the circulating medium outlet end (204, 304, 404) and the heating medium inlet (208, 308, 408, 508), the heater (210, 310, 410), a circulating medium input pipeline coupled between the circulating medium inlet end (205, 305, 405) and the heating medium outlet (209, 309, 409, 509), and the circulating medium inlet end (205, 305, 405).

2. The heat circulation system (200, 300, 400) for a fuel cell according to claim 1, wherein: The heater (210, 310, 410, 510, 600, 700) includes a first pipe (502, 602, 702) and a second pipe (501, 601, 701), the gas inlet (211, 311, 411, 511) and the gas outlet (212, 312, 412, 512) communicate with the first pipe (502, 602, 702), and the heating medium inlet (208, 308, 408, 508) and the heating medium outlet (209, 309, 409, 509) communicate with the second pipe (501, 601, 701).

3. The heat circulation system (200, 300, 400) of a fuel cell according to claim 2, wherein: The heater (210, 310, 410, 510, 600, 700) includes an inner tube and an outer tube. The gas inlet (211, 311, 411, 511) and the gas outlet (212, 312, 412, 512) communicate with the inner tube, and the heating medium inlet (208, 308, 408, 508) and the heating medium outlet (209, 309, 409, 509) communicate with the outer tube.

4. The heat circulation system (200, 300, 400) of a fuel cell according to claim 1, wherein: The heat circulation loop includes a first heat circulation loop (L1). The circulating medium output pipeline includes a first circulating medium output pipeline (206, 306, 406), and the circulating medium input pipeline includes a first circulating medium input pipeline (207, 307, 407); The fuel cell stack (201, 301, 401), the circulating medium outlet end (204, 304, 404), the first circulating medium output pipeline (206, 306, 406), the heating medium inlet (208, 308, 408, 508), the heater (210, 310, 410, 510, 600, 700), the heating medium outlet (209, 309, 409, 509), the first circulating medium input pipeline (207, 307, 407), and the circulating medium inlet end (205, 305, 405) form a first heat circulation loop (L1).

5. The heat circulation system (200, 300, 400) of a fuel cell according to claim 4, wherein: The heat circulation loop includes a second heat circulation loop (L2). The circulating medium output pipeline includes a second circulating medium output pipeline (316, 416), and the circulating medium input pipeline includes a second circulating medium input pipeline (317, 417); The fuel cell stack (201, 301, 401), the circulating medium outlet end (204, 304, 404), the second circulating medium output pipeline (316, 416), the second circulating medium input pipeline (317, 417), and the circulating medium inlet end (205, 305, 405) form a second heat circulation loop (L2).

6. The heat circulation system (200, 300, 400) of a fuel cell according to claim 5, further comprising: A radiator (315, 415) coupled between the circulating medium outlet end (204, 304, 404) and the circulating medium inlet end (205, 305, 405); wherein The stack (201, 301), the circulation medium outlet ends (204, 304, 404), the second circulation medium output pipelines (316, 416), the radiator (315), the second circulation medium input pipelines (317, 417), and the circulation medium inlet ends (205, 305, 405) form the second heat circulation loop (L2).

7. The heat circulation system (200, 300, 400) of the fuel cell according to claim 5, wherein: At least one of the first heat circulation loop (L1) and the second heat circulation loop (L2) includes a mass flow controller (V31, V32), and the mass flow controller (V31, V32) is configured to adjust the mass flow in the corresponding loop.

8. The heat circulation system (200, 300, 400) of the fuel cell according to claim 1, wherein: The mixer (220, 320, 420) is an ejector (220, 320, 420) and includes an ejector outlet (222, 322, 422), and the ejector outlet (222, 322, 422) is coupled to the gas inlet (211, 311, 411, 511) of the heater (210, 310, 410, 510, 600, 700), and the ejector (220, 320, 420) is configured to mix and compress the input multiple paths of gases.

9. The heat circulation system (200, 300, 400) of the fuel cell according to claim 1, wherein: The stack outlet ends (203, 303, 403) are coupled to the mixer inlets (223, 323, 423) of the mixer (220, 320, 420), and the exhaust gas output from the stack outlet ends (203, 303, 403) passes through the mixer (220, 320, 420) and the heater (210, 310, 410, 510, 600, 700) in sequence and then is input to the stack inlet ends (202, 302, 402).

10. The heat circulation system (200, 300, 400) of the fuel cell according to claim 1, further comprising: A first water separator (425), which is coupled between the heater (210, 310, 410, 510, 600, 700) and the stack inlet ends (202, 302, 402), and is configured to separate the liquid water in the gas output from the gas outlet (212, 312, 412, 512) of the heater (210, 310, 410, 510, 600, 700).

11. The heat circulation system (200, 300, 400) of the fuel cell according to claim 10, further comprising: A second water separator (426), which is coupled to the stack outlet ends (203, 303, 403), and is configured to separate the liquid water in the exhaust gas output from the stack outlet ends (203, 303, 403); The first water separator (425) is coupled to the second water separator (426) via a mass flow controller (V44).

12. The heat circulation system (200, 300, 400) of a fuel cell according to claim 11, The fuel cell stack includes an anode chamber, and the anode chamber includes the stack inlet end (202, 302, 402) and the stack outlet end (203, 303, 403).

13. A heat circulation method (800) of a fuel cell, comprising: Providing a heater (210, 310, 410, 510, 600, 700), the heater (210, 310, 410, 510, 600, 700) being coupled to the stack inlet end (202, 302, 402) of the fuel cell stack (201, 301, 401), and including a gas inlet (211, 311, 411, 511) for inputting gas, a gas outlet (212, 312, 412, 512) for outputting gas to the stack inlet end (202, 302, 402), a heating medium inlet (208, 308, 408, 508) coupled to the circulating medium outlet end (204, 304, 404) of the fuel cell stack (201, 301, 401), and a heating medium outlet (209, 309, 409, 509) coupled to the circulating medium inlet end (205, 305, 405) of the fuel cell stack (201, 301, 401); Providing a mixer (220, 320, 420), the mixer (220, 320, 420) including a mixer outlet (222, 322, 422), the mixer outlet (222, 322, 422) being coupled to the gas inlet (211, 311, 411, 511) of the heater (210, 310, 410, 510, 600, 700), and the mixer (220, 320, 420) being configured to mix the input gas; Providing a heat circulation loop, including the fuel cell stack (201, 301, 401), the circulating medium outlet end (204, 304, 404), a circulating medium output pipeline coupled between the circulating medium outlet end (204, 304, 404) and the heating medium inlet (208, 308, 408, 508), the heater (210, 310, 410), a circulating medium input pipeline coupled between the circulating medium inlet end (205, 305, 405) and the heating medium outlet (209, 309, 409, 509), and the circulating medium inlet end (205, 305, 405).

14. A fuel cell system (100), comprising the heat circulation system (200, 300, 400) of a fuel cell according to any one of claims 1 - 12.

15. A vehicle, comprising the fuel cell system (100) according to claim 14.

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