Fuel cell system and vehicle

Abstract

The utility model discloses a fuel cell system and a vehicle. The fuel cell system comprises at least one group of electric piles, a first preheater, a second preheater, a combustor and an air input unit, the electric pile comprises a first electric pile; the first electric pile comprises a first cathode inlet; the first preheater comprises a first inlet, a second inlet and a first outlet; the second preheater comprises a third inlet, a fourth inlet, a second outlet and a third outlet; the air input unit is communicated with the first inlet through a first pipeline and is communicated with the first cathode inlet through a second pipeline; the first outlet is communicated with the third inlet; the second outlet is communicated with the first cathode inlet; a combustion outlet of the combustor is communicated with the fourth inlet; the third outlet is communicated with the second outlet. According to the technical scheme, on one hand, low-cost materials can be selected for machining, and the cost of hot parts is reduced; and on the other hand, the design difficulty and the manufacturing cost of the hot part are reduced by reducing the heat exchange efficiency and the heat load of the hot part.

Description

Technical Field

[0001] This utility model relates to the field of fuel cell technology, and in particular to a fuel cell system and vehicle. Background Technology

[0002] For fuel cell power generation systems, there are upper and lower limits on temperature and airflow at the inlet and outlet of the fuel cell stack. If the temperature is too high, it will cause catalyst deactivation in the stack, resulting in stack degradation. If the temperature is too low, the stack will not reach its optimal operating state. To meet the stack temperature requirements, heat exchangers are installed on the air and gas sides to ensure stack performance and lifespan. Because existing fuel cell systems have high temperature requirements for heat exchangers, the cost increases accordingly, leading to high overall cost of thermal components in the fuel cell system and significant design challenges. Utility Model Content

[0003] This invention provides a fuel cell system and vehicle to solve the problems of high cost and design difficulty of thermal components in fuel cell systems.

[0004] According to one aspect of the present invention, a fuel cell system is provided, comprising at least one stack, a first preheater, a second preheater, a burner, and an air input unit;

[0005] The fuel cell stack includes a first fuel cell stack; the first fuel cell stack includes a first cathode inlet; the first preheater includes a first inlet, a second inlet, and a first outlet; the second preheater includes a third inlet, a fourth inlet, a second outlet, and a third outlet;

[0006] The air input unit is connected to the first inlet via a first pipe and to the first cathode inlet via a second pipe; the first outlet is connected to the third inlet; the second outlet is connected to the first cathode inlet; the combustion outlet of the burner is connected to the fourth inlet; and the third outlet is connected to the second outlet.

[0007] The air input unit is used to input air at the first temperature into the first cathode inlet and the first preheater, respectively;

[0008] The burner is used to input the combustion exhaust gas into the second preheater for heat exchange;

[0009] The first preheater is used to preheat air at a first temperature to air at a second temperature and to input the air at the second temperature into the second preheater;

[0010] The second preheater is used to preheat the second temperature air to the third temperature air and input the third temperature air to the first cathode inlet; wherein the temperature of the first temperature air is lower than the temperature of the second temperature air, and the temperature of the second temperature air is lower than the temperature of the third temperature air.

[0011] Optionally, the fuel cell system may also include a first mixer;

[0012] The first mixer is disposed on the second pipeline and between the second preheater and the first cathode inlet;

[0013] The first mixer is used to receive air at a first temperature and air at a third temperature, which are then mixed and fed into the first cathode inlet.

[0014] Optionally, the battery stack includes the i-th battery stack and the (i-1)-th battery stack; where i > 1 and is a positive integer;

[0015] The (i-1)th stack includes the (i-1)th cathode outlet; the i-th stack includes the i-th cathode inlet;

[0016] The (i-1)th cathode outlet is connected to the i-th cathode inlet; the i-th cathode inlet is connected to the air input unit through a third pipeline.

[0017] Optionally, the fuel cell system may also include a second mixer;

[0018] The second mixer is located on the third pipeline and between the (i-1)th cathode outlet and the i-th cathode inlet.

[0019] Optionally, the fuel cell system includes a first butterfly valve and a second butterfly valve;

[0020] The first butterfly valve is installed on the first pipeline; the second butterfly valve is installed on the second pipeline.

[0021] Optionally, the first preheater may also include a fourth outlet;

[0022] The fourth outlet is used to discharge the waste gas after heat exchange.

[0023] Optionally, the electric stack includes the nth electric stack; where n is the total number of electric stacks, n≥1 and is a positive integer;

[0024] The burner includes a first combustion inlet and a second combustion inlet;

[0025] The nth fuel cell stack includes the nth cathode outlet;

[0026] The first combustion inlet is connected to the nth cathode outlet; the second combustion inlet is used for fuel input.

[0027] Optionally, the fuel cell system may also include a reformer;

[0028] The first fuel cell stack includes the first anode inlet;

[0029] The reformer includes a first reforming inlet and a first reforming outlet; the first reforming outlet is connected to the first anode inlet;

[0030] The reformer is used to receive fuel entering through the first reforming inlet and reform the fuel before feeding it into the first anode inlet.

[0031] Optionally, the fuel cell system may also include a first mixer;

[0032] The first mixer is disposed on the second pipeline and between the second preheater and the first cathode inlet;

[0033] The reformer also includes a second reforming inlet and a second reforming outlet; the second outlet is connected to the second reforming inlet and the second reforming outlet is connected to the first mixer.

[0034] According to another aspect of the present invention, a vehicle is provided, including a fuel cell system for supplying power to the vehicle.

[0035] The technical solution of this utility model, by setting up a first preheater, a second preheater, and a burner, and connecting the fuel cell stack with the first preheater, the second preheater, the burner and the air input unit, achieves the reduction of the inlet and outlet temperatures of the first and second preheaters, allowing for the use of low-cost materials for processing and reducing the cost of the thermal components; on the other hand, by reducing the heat exchange efficiency and heat load of the thermal components, the design difficulty and manufacturing cost of the thermal components are reduced.

[0036] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a connection diagram of the first fuel cell system provided according to an embodiment of the present utility model;

[0039] Figure 2 This is a connection diagram of a second fuel cell system provided according to an embodiment of the present utility model. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] Figure 1 This is a connection diagram of a first type of fuel cell system provided according to an embodiment of the present utility model. Figure 1 As shown, the fuel cell system includes:

[0043] At least one set of fuel cell stack, first preheater 2, second preheater 3, burner 4 and air input unit 5;

[0044] The fuel cell stack includes a first fuel cell stack 10; the first fuel cell stack 10 includes a first cathode inlet 101; the first preheater 2 includes a first inlet 21, a second inlet 22, and a first outlet 23; the second preheater 3 includes a third inlet 31, a fourth inlet 32, a second outlet 33, and a third outlet 34;

[0045] Air input unit 5 is connected to first inlet 21 via first pipe a, and to first cathode inlet 101 via second pipe b; first outlet 23 is connected to third inlet 31; second outlet 33 is connected to first cathode inlet 101; combustion outlet of burner 4 is connected to fourth inlet 32; third outlet 34 is connected to second outlet 33.

[0046] Air input unit 5 is used to input air at the first temperature into the first cathode inlet 101 and the first preheater 2 respectively;

[0047] Burner 4 is used to input the combustion exhaust gas into the second preheater 3 for heat exchange;

[0048] The first preheater 2 is used to preheat air at a first temperature to air at a second temperature and to input the air at the second temperature into the second preheater 3;

[0049] The second preheater 3 is used to preheat the second temperature air to the third temperature air and input the third temperature air to the first cathode inlet 101; wherein the temperature of the first temperature air is lower than the temperature of the second temperature air, and the temperature of the second temperature air is lower than the temperature of the third temperature air.

[0050] The fuel cell can be a device that directly converts the chemical energy in fuel into electrical energy to power a vehicle. The fuel cell system may include at least one stack, each stack including an anode inlet, an anode outlet, a cathode inlet, and a cathode outlet. The first stack 10 may be the first stack in the fuel cell system to receive fuel and air, and the first stack 10 includes a first cathode inlet 101, which can be used to introduce air. An air input unit 5 can be used to supply air to the fuel cell system; in some embodiments, the air input unit 5 may be a fan.

[0051] The first preheater 2 and the second preheater 3 can be used to preheat the air to ensure that the air entering the first cathode inlet 101 reaches the specified temperature. Fuel reaction can occur in the burner 4, and the heat generated by the combustion reaction can be exchanged in the second preheater 3 to improve the energy utilization rate of the fuel cell system.

[0052] Specifically, the air input unit 5 is connected to the first inlet 21 of the first preheater 2 via a first pipe a, and to the first cathode inlet 101 via a second pipe b. This allows a portion of the first-temperature air input into the air input unit 5 to enter the first preheater 2 for heating, and a portion to enter the first cathode inlet 101. By adjusting the ratio of the first-temperature air in the first pipe a and the second pipe b, the air temperature at the first cathode inlet 101 can be adjusted, thereby ensuring that the air temperature entering the first cathode inlet 101 is a specified temperature. In some embodiments, the fuel cell system includes a first butterfly valve 61 and a second butterfly valve 62; the first butterfly valve 61 is disposed on the first pipe a; the second butterfly valve 62 is disposed on the second pipe b. By controlling the opening degree of the first butterfly valve 61 and the second butterfly valve 62, the air temperature entering the first cathode inlet 101 can be adjusted. Simultaneously, the first outlet 23 is connected to the third inlet 31, and the first preheater 2 preheats the first-temperature air to a second-temperature air and inputs it into the second preheater 3 for further preheating. The second outlet 33 is connected to the first cathode inlet 101. The second preheater 3 preheats the second temperature air to a third temperature air and inputs the third temperature air into the first cathode inlet 101. The third temperature air mixes with the first temperature air in the second pipeline b and then enters the first cathode inlet 101, thus regulating the air temperature at the first cathode inlet 101. Simultaneously, the combustion outlet of the burner 4 is connected to the fourth inlet 32, allowing the high-temperature hot air in the burner 4 to enter the second preheater 3. The second temperature air combines with the high-temperature hot air and is heated to the third temperature air. Simultaneously, the high-temperature hot air, after heat exchange, cools down to a medium temperature air. The third outlet 34 is connected to the second outlet 33, allowing the medium-temperature hot air to enter the first preheater 2 to assist in heat exchange, preheating the first temperature air to the second temperature air. Since the burner 4 is directly connected to the second preheater 3, the preheating temperature of the second preheater 3 is higher than that of the first preheater 2.

[0053] Understandably, the stronger the heating capacity of a preheater, the higher its manufacturing cost and the greater the design difficulty of its thermal components.

[0054] For example, in terms of cost, when only one preheater is set in the fuel cell system, the combustion outlet of burner 4 is directly connected to the preheater. At this time, it is necessary to raise the temperature of the first air from 30°C to about 700°C, and the high-temperature hot air output from the combustion outlet of burner 4 is about 800°C. Therefore, the preheater has high temperature requirements and strong corrosion resistance. Generally, 310S stainless steel is selected for processing. 310S has excellent high temperature resistance and is suitable for high temperature environments below 1200°C. However, from a cost perspective, 310S is expensive. In terms of raw material cost, the high nickel content makes it expensive and may require additional processing, resulting in high processing costs. In terms of market supply and demand, the price fluctuation of nickel affects the cost of 310S. In this embodiment of the invention, two preheaters are used for staged preheating. The second preheater 3 is directly connected to the burner 4. The high-temperature hot air output by the burner 4 can be reduced to below 550°C after heat exchange before being introduced into the first preheater 2. Since the air temperature received by the first preheater 2 is below 550°C, the first preheater 2 can be made of a lower-cost material, such as 316L stainless steel. 316L has excellent corrosion resistance, especially in humid, corrosive media and high-salt environments. In medium and normal temperature environments (below 550°C), 316L can still maintain good corrosion resistance and mechanical properties, and the cost of 316L is lower than that of 310S. In terms of material costs, 316L has a low nickel content, resulting in low material costs. In terms of processing costs, the production process of 316L is relatively mature, widely used, and produced on a large scale, thus its production costs are relatively low. In terms of market supply and demand, 316L is widely used in construction, food processing, medical equipment, and other fields, with large market demand, sufficient supply, and relatively stable and competitive market prices.

[0055] For example, regarding design difficulty, when only one preheater is set in the fuel cell system, the combustion outlet of the burner 4 is directly connected to the preheater. In this case, the first temperature air needs to be heated from 30°C to about 700°C, and the heat exchange efficiency of the air preheater needs to reach more than 90%, making the design of the air preheater difficult. In this embodiment of the utility model, in order to alleviate the heat exchange design pressure of the preheater, the air preheater is divided into a first preheater 2 and a second preheater 3. The first preheater 2 heats the first temperature air to above 400°C, and the preheated air then enters the second preheater 3 and is heated to about 650°C. This can reduce the heat exchange efficiency of a single air preheater. The heat exchange efficiency of the first and second heat exchangers can be reduced to 70% to meet the heat exchange requirements, reducing the design difficulty of the thermal components.

[0056] Therefore, the connection method based on this fuel cell system in the embodiments of this utility model can reduce the cost and design difficulty of the thermal components in the fuel cell system while ensuring the working efficiency of the fuel cell system.

[0057] The technical solution of this utility model embodiment, by setting up a first preheater, a second preheater, and a burner, and connecting the fuel cell stack with the first preheater, the second preheater, the burner, and the air input unit, achieves the reduction of the inlet and outlet temperatures of the first and second preheaters, allowing for the use of low-cost materials for processing and reducing the cost of the thermal components; on the other hand, by reducing the heat exchange efficiency and heat load of the thermal components, the design difficulty and manufacturing cost of the thermal components are reduced.

[0058] Optional, continue to refer to Figure 1 As shown, the fuel cell system also includes a first mixer 71;

[0059] The first mixer 71 is disposed on the second pipeline b and between the second preheater 3 and the first cathode inlet 101;

[0060] The first mixer 71 is used to receive air at a first temperature and air at a third temperature mixed together and then input to the first cathode inlet 101.

[0061] The first mixer 71 serves to mix air at a first temperature and air at a third temperature. The first mixer 71 is installed on the second pipeline b and is located between the second preheater 3 and the first cathode inlet 101. The first mixer 71 receives air at the first temperature and air at the third temperature that has been preheated by the second preheater 3, mixes them, and then inputs them into the first cathode inlet 101 to ensure that the air temperature entering the first cathode inlet 101 reaches the specified temperature.

[0062] The technical solution of this utility model embodiment, by setting a first mixer, which is located on the second pipeline and between the second preheater and the first cathode inlet, ensures that the air temperature entering the first cathode inlet reaches a specified temperature, thereby guaranteeing the operating efficiency of the fuel cell system.

[0063] Optional, Figure 2 This is a connection diagram of a second fuel cell system according to an embodiment of the present invention, as shown below. Figure 2 As shown, the battery stack includes the i-th battery stack 11 and the (i-1)-th battery stack; where i > 1 and is a positive integer;

[0064] The (i-1)th stack includes the (i-1)th cathode outlet; the i-th stack 11 includes the i-th cathode inlet 111;

[0065] The (i-1)th cathode outlet is connected to the i-th cathode inlet 111; the i-th cathode inlet 111 is connected to the air input unit 5 through the third pipe c.

[0066] The fuel cell system may include at least two stacks, with at least one first stack 10 and one i-th stack 11. The (i-1)th stack may be the first stack 10 or any stack other than the i-th stack 11 and the (i-1)th stack. Each stack includes a cathode outlet and a cathode inlet, i.e., the (i-1)th stack includes the (i-1)th cathode outlet; the i-th stack 11 includes the i-th cathode inlet 111.

[0067] Specifically, the (i-1)th cathode outlet is connected to the i-th cathode inlet 111, so that the i-th stack 11 and the (i-1)th stack are connected in series, realizing multi-stage utilization of the air side. At the same time, the i-th cathode inlet 111 is connected to the air input unit 5 through the third pipe c, ensuring sufficient air volume on the air side of the i-th cathode inlet 111, thereby ensuring the operating efficiency of the fuel cell system.

[0068] In some embodiments, a third butterfly valve 63 may be included, which is installed on the third pipeline c. The opening degree of the third butterfly valve 63 can be controlled to control the amount of air entering the cathode inlet. Each butterfly valve can adjust the air input ratio. Since different types of solid oxide fuel cells have different upper and lower limits for the stack inlet temperature, the air flow rate entering the pipeline can be controlled by adjusting the butterfly valves until it is adjusted to the inlet air temperature range required by the stack, thereby improving the durability of the stack and avoiding stack degradation caused by long-term system operation.

[0069] The technical solution of this utility model embodiment improves air utilization while ensuring the operating efficiency of the fuel cell by setting up a multi-stage fuel cell stack connected in series, and by setting up air input units that are directly connected to the cathode inlet of each fuel cell stack through pipelines.

[0070] Optional, continue to refer to Figure 2 As shown, the fuel cell system also includes a second mixer 72;

[0071] The second mixer 72 is disposed on the third pipeline c and is located between the (i-1)th cathode outlet and the i-th cathode inlet 111.

[0072] The second mixer 72 can be used to mix the air output from the (i-1)th cathode outlet with the air at the first temperature and then input it into the i-th cathode inlet 111, thereby ensuring the temperature of the air entering the i-th cathode inlet 111 and ensuring the efficiency of the fuel cell system operation.

[0073] Optional, continue to refer to Figure 1 As shown, the first preheater 2 also includes a fourth outlet 24;

[0074] The fourth outlet 24 is used to discharge the waste gas after heat exchange.

[0075] The fourth outlet 24 can be used to discharge the air after heat exchange in the first preheater 2. The high-temperature hot air output from the combustion outlet of the burner 4 is discharged through the fourth outlet 24 after heat exchange in the second preheater 3 and the first preheater 2, thus completing the multi-stage utilization of heat and improving the operating efficiency of the fuel cell system.

[0076] Optional, continue to refer to Figure 1 and Figure 2 As shown, the electric stack includes the nth electric stack; where n is the total number of electric stacks, n≥1 and is a positive integer;

[0077] The burner 4 includes a first combustion inlet 41 and a second combustion inlet 42;

[0078] The nth fuel cell stack includes the nth cathode outlet;

[0079] The first combustion inlet 41 is connected to the nth cathode outlet; the second combustion inlet 42 is used for fuel input.

[0080] The nth fuel cell stack can be the last fuel cell stack to receive fuel in the fuel cell system. The burner 4 is also connected to the nth cathode outlet, and the hot air output from the nth cathode outlet can directly enter the first combustion inlet 41 to provide oxygen for the combustion reaction of the burner 4, thereby improving air utilization and realizing efficient resource utilization.

[0081] It is understandable that, regardless of the number of fuel cell stacks in the system, burner 4 is always connected to the cathode outlet of the last stack. For example, Figure 1 The middle burner 4 is connected to the first cathode outlet 102. Figure 2 The middle section is connected to the second cathode outlet 112, which improves air utilization and realizes the effective use of resources.

[0082] Optional, continue to refer to Figure 2 As shown, the fuel cell system also includes a reformer 8;

[0083] The first fuel cell stack 10 includes a first anode inlet 103;

[0084] The reformer 8 includes a first reforming inlet 81 and a first reforming outlet 82; the first reforming outlet 82 is connected to the first anode inlet 103;

[0085] The reformer 8 is used to receive fuel entering through the first reforming inlet 81 and reform the fuel to produce hydrogen, which is then fed into the first anode inlet 103.

[0086] The first reforming inlet 81 can be used to receive fuel input to the first anode inlet 103. The fuel is input to the first anode inlet 103 after undergoing a reforming reaction in the reformer 8.

[0087] For example, such as Figure 2 As shown, fuel and water are mixed and heated in evaporator 91, then enter reformer 8 for water-gas reforming to produce hydrogen, which enters the first fuel cell stack 10 to generate electricity. After passing through fuel heat exchanger 92 for cooling, condenser 93 for condensation, and separator 94 for water removal, the resulting fuel is mixed with afterburner and enters fuel heat exchanger 92 for heating. When heated to a specified temperature, it enters the second fuel cell stack to continue generating electricity. The remaining gas from the anode outlet of the second fuel cell stack is fed into burner 4 for combustion. The high-temperature exhaust gas from combustion enters the second preheater 3 and the first preheater 2 in sequence to provide heat source for preheating cold air. The exhaust gas discharged from the fourth outlet 24 of the first preheater 2 enters evaporator 91 to heat the fuel-water mixture. Finally, the exhaust gas is discharged from the system.

[0088] In some embodiments, the fuel cell system further includes a first mixer 71; the first mixer 71 is disposed on the second pipeline b and between the second preheater 3 and the first cathode inlet 101; the reformer 8 further includes a second reforming inlet 83 and a second reforming outlet 84; the second outlet 33 is connected to the second reforming inlet 83, and the second reforming outlet 84 is connected to the first mixer 71. This arrangement allows air preheated by the second preheater 3 at a third temperature to enter the reformer 8 to provide heat for the reforming reaction. The hot air from the second reforming outlet 84 mixes with the first mixer 71 to reach a specified temperature before entering the first cathode inlet 101 of the first fuel cell stack 10. This provides the required temperature for the reforming reaction and ensures the air temperature entering the first cathode inlet 101, thereby improving the system's fuel utilization rate while ensuring that the fuel utilization rate of the single-stage fuel cell stack is not too high, and further improving the system's power generation efficiency.

[0089] The technical solution of this utility model embodiment improves the system's fuel utilization rate by setting up a reformer and connecting the reformer to the first anode inlet and the first mixer, thereby further improving the system's power generation efficiency while ensuring that the fuel utilization rate of the single-stage fuel stack is not too high.

[0090] Based on the same inventive concept, this utility model embodiment also provides a vehicle, including a fuel cell system for supplying power to the vehicle.

[0091] The fuel cell system can be installed in the vehicle to provide power and ensure its normal operation.

[0092] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A fuel cell system, characterized in that, It includes at least one set of fuel cell stack, a first preheater, a second preheater, a burner, and an air input unit; The fuel cell stack includes a first fuel cell stack; the first fuel cell stack includes a first cathode inlet; the first preheater includes a first inlet, a second inlet, and a first outlet; the second preheater includes a third inlet, a fourth inlet, a second outlet, and a third outlet; The air input unit is connected to the first inlet via a first pipe and to the first cathode inlet via a second pipe; the first outlet is connected to the third inlet; the second outlet is connected to the first cathode inlet; the combustion outlet of the burner is connected to the fourth inlet; and the third outlet is connected to the second outlet. The air input unit is used to input air at a first temperature into the first cathode inlet and the first preheater, respectively. The burner is used to input the combustion exhaust gas into the second preheater for heat exchange; The first preheater is used to preheat the first temperature air to the second temperature air and input the second temperature air into the second preheater; The second preheater is used to preheat the second temperature air to a third temperature air and input the third temperature air to the first cathode inlet; wherein the temperature of the first temperature air is lower than the temperature of the second temperature air, and the temperature of the second temperature air is lower than the temperature of the third temperature air.

2. The fuel cell system according to claim 1, characterized in that, The fuel cell system also includes a first mixer; The first mixer is disposed on the second pipeline and between the second preheater and the first cathode inlet; The first mixer is used to receive the first temperature air and the third temperature air mixed together and input to the first cathode inlet.

3. The fuel cell system according to claim 1, characterized in that, The battery stack includes the i-th battery stack and the (i-1)-th battery stack; where i > 1 and is a positive integer; The (i-1)th stack includes the (i-1)th cathode outlet; the i-th stack includes the i-th cathode inlet; The (i-1)th cathode outlet is connected to the i-th cathode inlet; the i-th cathode inlet is connected to the air input unit through a third pipeline.

4. The fuel cell system according to claim 3, characterized in that, The fuel cell system also includes a second mixer; The second mixer is disposed on the third pipeline and between the (i-1)th cathode outlet and the i-th cathode inlet.

5. The fuel cell system according to claim 1, characterized in that, The fuel cell system includes a first butterfly valve and a second butterfly valve; The first butterfly valve is installed on the first pipeline; the second butterfly valve is installed on the second pipeline.

6. The fuel cell system according to claim 1, characterized in that, The first preheater also includes a fourth outlet; The fourth outlet is used to discharge the waste gas after heat exchange.

7. The fuel cell system according to claim 1, characterized in that, The electric stack includes the nth electric stack; where n is the total number of electric stacks, n≥1 and is a positive integer; The burner includes a first combustion inlet and a second combustion inlet; The nth stack includes the nth cathode outlet; The first combustion inlet is connected to the nth cathode outlet; the second combustion inlet is used to input fuel.

8. The fuel cell system according to claim 1, characterized in that, The fuel cell system also includes a reformer; The first fuel cell stack includes a first anode inlet; The reformer includes a first reforming inlet and a first reforming outlet; the first reforming outlet is connected to the first anode inlet; The reformer is used to receive fuel entering through the first reforming inlet and reform the fuel before inputting it into the first anode inlet.

9. The fuel cell system according to claim 8, characterized in that, The fuel cell system also includes a first mixer; The first mixer is disposed on the second pipeline and between the second preheater and the first cathode inlet; The reformer further includes a second reforming inlet and a second reforming outlet; the second outlet is connected to the second reforming inlet, and the second reforming outlet is connected to the first mixer.

10. A vehicle, characterized in that, Includes the fuel cell system according to any one of claims 1-9, said fuel cell system being used to power a vehicle.

Images