A heat exchange device and a fuel cell system

Abstract

This invention discloses a heat exchange device and system based on a fuel cell. The system includes a primary heat exchange module, a burner, and a secondary heat exchange module. The hot-side input of the primary heat exchange module is connected to the exhaust gas output of the fuel cell stack, the hot-side output of the primary heat exchange module is connected to the input of the burner, the output of the burner is connected to the hot-side input of the secondary heat exchange module, and the cold-side output of the secondary heat exchange module is connected to the input of the fuel cell stack. By placing the primary heat exchange module between the burner and the exhaust gas output of the fuel cell stack, the temperature of the fuel cell stack exhaust gas entering the burner is reduced, thereby reducing the temperature of the burner during combustion and the temperature of the exhaust gas output. This lowers the heat resistance requirements of the burner and the heat exchange module, reducing implementation costs. The design of the primary and secondary heat exchange modules reduces the amount of exhaust gas distributed by the burner, simplifying the design. This invention can be widely applied in the field of fuel cell technology.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a heat exchange device and a fuel cell system. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are all-solid-state chemical power generation devices that directly convert the chemical energy of hydrocarbon fuels into electrical energy. Existing SOFC systems typically utilize heat exchange networks to recover energy from the stack exhaust gas emitted by the fuel cell stack. The heat exchange network burns the stack exhaust gas through a burner, outputting high-temperature exhaust gas to heat the fuel, air, and water required by the SOFC system, thereby improving power generation efficiency and energy utilization. However, the heating requirements for fuel, air, and water are different, and the design of the high-temperature exhaust gas distribution ratio in the burner of existing heat exchange networks is difficult. At the same time, the high-temperature exhaust gas output by the burner in existing heat exchange networks can reach up to 900°C, posing a risk of burner overheating. This places high demands on the heat resistance of the burner and heat exchange devices, resulting in high implementation costs. Summary of the Invention

[0003] The main objective of this invention is to provide a heat exchange device and a fuel cell system that can reduce the difficulty of flow distribution design and reduce implementation costs.

[0004] To achieve the above objectives, one aspect of the present invention provides a heat exchange device connected to an electric fuel cell stack. The device includes a primary heat exchange module, a burner, and a secondary heat exchange module; wherein...

[0005] The hot-side input terminal of the primary heat exchange module is connected to the exhaust gas output terminal of the fuel cell stack, and the hot-side output terminal of the primary heat exchange module is connected to the input terminal of the burner.

[0006] The output end of the burner is connected to the heat-side input end of the secondary heat exchange module;

[0007] The cold-side output terminal of the secondary heat exchange module is connected to the input terminal of the fuel cell stack.

[0008] In some embodiments, the secondary heat exchange module includes a flow divider, a first heat exchanger, and a second heat exchanger; wherein...

[0009] The input end of the flow divider is connected to the output end of the burner, the first output end of the flow divider is connected to the first heat exchanger, and the second output end of the flow divider is connected to the second heat exchanger.

[0010] In some embodiments, the secondary heat exchange module includes a third heat exchanger and a fourth heat exchanger; wherein,

[0011] The hot-side input terminal of the third heat exchanger is connected to the output terminal of the burner, and the hot-side output terminal of the third heat exchanger is connected to the hot-side input terminal of the fourth heat exchanger.

[0012] In some embodiments, the primary heat exchange module includes an evaporator; wherein...

[0013] The hot-side input terminal of the evaporator is connected to the exhaust gas output terminal of the fuel cell stack, the cold-side input terminal of the evaporator is connected to liquid water, and the hot-side output terminal of the evaporator is connected to the input terminal of the burner.

[0014] In some embodiments, the apparatus further includes a pre-reformer, and the primary heat exchange module includes a gas heat exchanger; wherein...

[0015] The hot-side input terminal of the gas heat exchanger is connected to the exhaust gas output terminal of the fuel cell stack, the cold-side input terminal of the gas heat exchanger is connected to the output terminal of the pre-reformer, the cold-side output terminal of the gas heat exchanger is connected to the input terminal of the fuel cell stack, and the hot-side output terminal of the gas heat exchanger is connected to the input terminal of the burner.

[0016] In some embodiments, the apparatus further includes a mixer, and the secondary heat exchange module includes an air heat exchanger and an evaporator; wherein...

[0017] The output end of the burner is connected to the hot side input end of the air heat exchanger and the hot side input end of the evaporator, respectively.

[0018] The cold-side input terminal of the air heat exchanger is connected to an air source, and the cold-side output terminal of the air heat exchanger is connected to the input terminal of the fuel cell stack.

[0019] The cold-side input terminal of the evaporator is connected to liquid water, and the cold-side output terminal of the evaporator is connected to the input terminal of the mixer;

[0020] The mixer is used to mix fuel and high-temperature steam; the first input terminal of the mixer is connected to the fuel source, the second input terminal of the mixer is connected to the output terminal of the water evaporator, and the output terminal of the mixer is connected to the input terminal of the pre-reformer.

[0021] The pre-reformer is used to reform the fuel to obtain reformed fuel; the output of the pre-reformer is connected to the primary heat exchange module or the secondary heat exchange module.

[0022] In some embodiments, the exhaust gas output terminal of the fuel cell system includes an anode output terminal and a cathode output terminal.

[0023] In some embodiments, the anode output terminal is connected to the hot-side input terminal of the primary heat exchange module, and the cathode output terminal is connected to the input terminal of the burner.

[0024] In some embodiments, the cathode output terminal is connected to the hot-side input terminal of the primary heat exchange module, and the anode output terminal is connected to the input terminal of the burner.

[0025] To achieve the above objectives, another aspect of the present invention provides a fuel cell system, the system including a fuel cell stack and a heat exchange network; wherein,

[0026] The fuel cell stack is used to generate electricity and produce fuel cell exhaust gas;

[0027] The heat exchange network includes any of the aforementioned devices for exchanging heat with the fuel based on the fuel stack exhaust gas.

[0028] Implementing the embodiments of the present invention has the following beneficial effects: This embodiment provides a heat exchange device and a fuel cell system. The solution includes a primary heat exchange module, a burner, and a secondary heat exchange module. The hot-side input terminal of the primary heat exchange module is connected to the exhaust gas output terminal of the fuel cell stack, the hot-side output terminal of the primary heat exchange module is connected to the input terminal of the burner, the output terminal of the burner is connected to the hot-side input terminal of the secondary heat exchange module, and the cold-side output terminal of the secondary heat exchange module is connected to the input terminal of the fuel cell stack. By setting a primary heat exchange module between the burner and the exhaust gas output terminal of the fuel cell stack, the high temperature of the fuel cell stack exhaust gas is used as the heat source for the primary heat exchange module to heat the material input to the primary heat exchange module, while reducing the temperature of the fuel cell stack exhaust gas entering the burner, reducing the risk of burner overheating. Placing the primary heat exchange module before the burner reduces the difficulty of exhaust gas distribution from the burner, reduces the heat resistance requirements of the burner and the heat exchange module, and reduces the implementation cost. Attached Figure Description

[0029] Figure 1 This is a structural block diagram of a heat exchange device provided in an embodiment of the present invention;

[0030] Figure 2 This is a structural block diagram of a mixer and a pre-reformer in a heat exchange device provided in an embodiment of the present invention;

[0031] Figure 3 This is a structural block diagram of a secondary heat exchange module in a heat exchange device provided in an embodiment of the present invention;

[0032] Figure 4 This is a structural block diagram of a heat exchange device provided in an embodiment of the present invention;

[0033] Figure 5 This is another structural block diagram of a heat exchange device provided in an embodiment of the present invention;

[0034] Figure 6 This is a structural block diagram of another secondary heat exchange module in a heat exchange device provided in an embodiment of the present invention;

[0035] Figure 7 This is a structural block diagram of an electric stack connection in a heat exchange device provided in an embodiment of the present invention;

[0036] Figure 8 This is a structural block diagram of another type of electric stack connection in a heat exchange device provided in an embodiment of the present invention;

[0037] Figure 9 This is a structural block diagram of a fuel cell system provided in an embodiment of the present invention. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

[0039] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0040] In the following description, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of the invention described herein can be implemented in an order other than that illustrated or described herein.

[0041] Unless otherwise defined, all technical and scientific terms used in the embodiments of this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in the embodiments of this invention is for descriptive purposes only and is not intended to limit the invention.

[0042] Please see Figure 1 , Figure 1 This invention provides a heat exchange device based on a fuel cell system, comprising a primary heat exchange module, a burner, and a secondary heat exchange module; wherein,

[0043] The hot-side input terminal of the primary heat exchange module is connected to the exhaust gas output terminal of the fuel cell stack, and the hot-side output terminal of the primary heat exchange module is connected to the input terminal of the burner.

[0044] The burner's output is connected to the heat-side input of the secondary heat exchange module;

[0045] The cold-side output of the secondary heat exchange module is connected to the input of the fuel cell stack.

[0046] In some embodiments, the heat exchange device is connected to the fuel cell stack. The hot-side input terminal of the primary heat exchange module in the heat exchange device is connected to the exhaust gas output terminal of the fuel cell stack. The exhaust gas output from the fuel cell stack provides a heat source for the primary heat exchange module, heating the material input to the primary heat exchange module and lowering the temperature of the exhaust gas. The hot-side output terminal of the primary heat exchange module is connected to the input terminal of the burner. The primary heat exchange module outputs the heat-exchanged exhaust gas to the burner, where it is burned, raising the exhaust gas temperature. The burner outputs the heated exhaust gas to the secondary heat exchange module connected to the burner, providing a heat source for the secondary heat exchange module and heating the material input to the secondary heat exchange module. The secondary heat exchange module uses the high-temperature exhaust gas output from the burner to heat the input material and outputs the heated material to the fuel cell stack. The fuel cell uses the heated material to perform an electrochemical reaction to generate electricity.

[0047] Please see Figure 2 In some embodiments, the heat exchange device based on a fuel cell system provided by the present invention further includes a mixer and a pre-reformer; wherein,

[0048] A mixer is used to mix fuel and high-temperature steam; the first input of the mixer is connected to the fuel source, the second input of the mixer is connected to the high-temperature steam, and the output of the mixer is connected to the input of the pre-reformer.

[0049] The pre-reformer is used to reform the fuel to obtain reformed fuel; the output of the pre-reformer is connected to a primary heat exchange module or a secondary heat exchange module.

[0050] In some embodiments, fuel cells utilize hydrocarbon fuels to generate electricity. To improve the power generation efficiency of the fuel cell and avoid carbon buildup inside the fuel cell, a mixer and a pre-reformer are provided in the heat exchange device. The hydrocarbon fuel in the fuel cell undergoes a chemical reaction with water to convert multi-carbon hydrocarbons into low-carbon compounds, which are then fed into the fuel cell for electrochemical reaction. In this embodiment, the input end of the mixer is connected to both fuel and high-temperature steam. The high-temperature steam is obtained by a primary or secondary heat exchange module that heats liquid water by exchanging heat with fuel cell stack exhaust gas or burner exhaust gas. The mixer mixes the fuel and high-temperature steam and outputs the mixture to the pre-reformer. The input end of the pre-reformer is connected to the output end of the mixer and receives the fuel-high-temperature steam mixture output by the mixer. The high-temperature steam mixture provides suitable temperature conditions for the pre-reformer to carry out the pre-reformation reaction. The pre-reformer outputs the reformed fuel to the connected primary or secondary heat exchange module, where the reformed fuel is heated to the temperature required for the fuel cell to carry out the electrochemical reaction.

[0051] Please see Figure 3 In some embodiments, the secondary heat exchange module in a heat exchange device based on a fuel cell system provided by the present invention includes a flow divider, a first heat exchanger, and a second heat exchanger; wherein,

[0052] The input end of the flow divider is connected to the output end of the burner, the first output end of the flow divider is connected to the first heat exchanger, and the second output end of the flow divider is connected to the second heat exchanger.

[0053] In some embodiments, the secondary heat exchange module is provided with two different types of heat exchangers and a flow divider. The input end of the flow divider is connected to the output end of the burner, and the output end of the flow divider is connected to the hot-side input ends of the two different types of heat exchangers respectively, realizing a parallel structure of the heat exchangers. The flow divider is structurally designed according to the heating requirements of the heat exchangers connected to it, realizing different distribution ratios of the high-temperature exhaust gas output by the burner, and simultaneously outputting the high-temperature exhaust gas output by the burner to the parallel structure of the heat exchangers, serving as a heat source to exchange heat with the first substance input to the first heat exchanger in the secondary heat exchange module, and to exchange heat with the second substance input to the second heat exchanger in the secondary heat exchange module. The first and second heat exchangers output the heat-exchanged first and second substances to the connected devices, such as the fuel cell stack. By realizing the parallel structure of the heat exchangers through the flow divider, the maximum temperature of the heat-exchanged and heated substances output by the heat exchangers is closer to the temperature of the high-temperature exhaust gas output by the burner, realizing a larger output temperature range design.

[0054] Please see Figure 4 In some embodiments, the primary heat exchange module of a heat exchange device based on a fuel cell system provided by the present invention includes an evaporator, and the secondary heat exchange module includes an air heat exchanger and a gas heat exchanger; wherein,

[0055] The hot-side input terminal of the evaporator is connected to the exhaust gas output terminal of the fuel cell stack, the cold-side input terminal of the evaporator is connected to liquid water, the hot-side output terminal of the evaporator is connected to the input terminal of the burner, and the cold-side output terminal of the evaporator is connected to the input terminal of the mixer.

[0056] The output end of the burner is connected to the hot side input end of the air heat exchanger and the hot side input end of the gas heat exchanger, respectively.

[0057] The output of the pre-reformer is connected to the cold-side input of the gas heat exchanger;

[0058] The cold-side inlet of the air heat exchanger is connected to the air source, and the cold-side outlet of the air heat exchanger is connected to the inlet of the fuel cell stack.

[0059] The cold-side output of the gas heat exchanger is connected to the input of the fuel cell stack.

[0060] In some embodiments, the evaporator is used as a primary heat exchange module, and the air heat exchanger and gas heat exchanger are used as secondary heat exchange modules. The hot-side input of the evaporator is connected to the fuel cell stack exhaust gas output, and the hot-side output of the evaporator is connected to the input of the burner. The evaporator uses the high-temperature exhaust gas output from the fuel cell stack as a heat source to heat and raise the temperature of the liquid water input to the evaporator, outputting high-temperature water vapor. The cooled fuel cell stack exhaust gas is then output to the burner, and the high-temperature water vapor is output to a connected mixer. The burner combusts the cooled fuel cell stack exhaust gas output from the evaporator, raising the exhaust gas temperature. The heated exhaust gas is simultaneously output to the hot-side inputs of both the air heat exchanger and the gas heat exchanger, providing a heat source for both. The mixer's input... The fuel cell is connected to a fuel source, where it mixes fuel supplied by the fuel source with high-temperature steam output from the evaporator. The mixed high-temperature steam and fuel are then output to a pre-reformer, which reforms the high-temperature steam and fuel. The reformed fuel is then output to a gas heat exchanger connected to the pre-reformer. The gas heat exchanger uses the high-temperature exhaust gas output from the burner as a heat source to heat the reformed fuel. The heated reformed fuel is then output to the fuel cell stack input. The cold-side input of the air heat exchanger is connected to a fan or other equipment to supply ambient temperature air to the air heat exchanger. The air heat exchanger uses the high-temperature exhaust gas output from the burner as a heat source to heat the ambient temperature air input to the cold-side input, and then outputs the high-temperature air to the fuel cell stack input through the cold-side output.

[0061] Please see Figure 5 In some embodiments, the primary heat exchange module of the heat exchange device based on a fuel cell system provided by the present invention includes a gas heat exchanger, and the secondary heat exchange module includes an air heat exchanger and an evaporator; wherein,

[0062] The hot-side input terminal of the gas heat exchanger is connected to the exhaust gas output terminal of the fuel cell stack, the cold-side input terminal of the gas heat exchanger is connected to the output terminal of the pre-reformer, the cold-side output terminal of the gas heat exchanger is connected to the input terminal of the fuel cell stack, and the hot-side output terminal of the gas heat exchanger is connected to the input terminal of the burner.

[0063] The output end of the burner is connected to the hot side input end of the air heat exchanger and the hot side input end of the evaporator, respectively.

[0064] The cold-side inlet of the air heat exchanger is connected to the air source, and the cold-side outlet of the air heat exchanger is connected to the inlet of the fuel cell stack.

[0065] The cold-side inlet of the evaporator is connected to liquid water, and the cold-side outlet of the evaporator is connected to the inlet of the mixer.

[0066] In some embodiments, a gas heat exchanger is used as a primary heat exchange module, and an air heat exchanger and an evaporator are used as secondary heat exchange modules. The input end of the gas heat exchanger is connected to the exhaust gas output end of the fuel cell stack, using the high-temperature exhaust gas output from the fuel cell stack as a heat source to heat and raise the temperature of the reformed fuel output from the pre-reformer. The input end of the pre-reformer is connected to the output end of a mixer, and the input end of the mixer is connected to both the fuel source and the cold-side output end of the evaporator, mixing the fuel provided by the fuel source with the high-temperature steam output from the evaporator and outputting the mixture to the pre-reformer. The pre-reformer reforms the fuel and the high-temperature steam to obtain reformed fuel, and outputs the reformed fuel to the gas heat exchanger. After the gas heat exchanger heats and raises the temperature of the reformed fuel, it outputs the heated reformed fuel to the gas heat exchanger. The heat exchanged and cooled exhaust gas from the fuel cell stack is sent to the input terminal of the fuel cell stack and then to the connected burner. The burner heats the cooled exhaust gas to produce high-temperature exhaust gas, which is then simultaneously sent to the air heat exchanger and the evaporator to provide a heat source for them. The evaporator uses the high-temperature exhaust gas from the burner as a heat source to heat the liquid water entering the evaporator to produce high-temperature steam, which is then sent to the mixer. The air heat exchanger uses the high-temperature exhaust gas from the burner as a heat source to heat the ambient air supplied by the fan and other equipment to produce high-temperature air, which is then sent to the fuel cell stack input terminal. The fuel cell uses the high-temperature air and high-temperature reformed fuel at the fuel cell stack input terminal to perform an electrochemical reaction to generate electricity.

[0067] Please see Figure 6 In some embodiments, the secondary heat exchange module in a heat exchange device based on a fuel cell system provided by the present invention includes a third heat exchanger and a fourth heat exchanger; wherein,

[0068] The hot-side input terminal of the third heat exchanger is connected to the output terminal of the burner, and the hot-side output terminal of the third heat exchanger is connected to the hot-side input terminal of the fourth heat exchanger.

[0069] In some embodiments, different types of heat exchangers in the secondary heat exchange module can be configured in series. The hot-side input terminal of any heat exchanger is connected to the output terminal of the burner, and the hot-side output terminal of one heat exchanger is connected to the hot-side input terminal of any other heat exchanger, and so on, to obtain a series-structured secondary heat exchange module. The first heat exchanger in the series structure uses the high-temperature exhaust gas output from the burner as a heat source to heat and raise the temperature of the substance (third substance) input to the heat exchanger, and outputs the cooled burner exhaust gas to the next connected heat exchanger. The next heat exchanger uses the cooled burner exhaust gas as a heat source to heat and raise the temperature of the input substance (fourth substance), until the burner exhaust gas is output to the last heat exchanger in the series structure, which then serves as a heat source to heat and raise the temperature of the substance input to the last heat exchanger. In the series-structured secondary heat exchange module, the burner exhaust gas temperature decreases significantly at each stage, making it suitable for scenarios with low temperature requirements.

[0070] In some embodiments, the exhaust gas output terminal of the fuel cell system in the heat exchange device system based on the fuel cell provided by the present invention includes an anode output terminal and a cathode output terminal; both the anode output terminal and the cathode output terminal output stack exhaust gas, and the anode exhaust gas output from the anode output terminal and the cathode exhaust gas output from the cathode output terminal can be output to the primary heat exchange module for heat exchange; in this embodiment, the anode exhaust gas is used for heat exchange.

[0071] Please see Figure 7 In some embodiments, the anode output terminal of the heat exchange device based on a fuel cell system provided by the present invention is connected to the hot side input terminal of the first-stage heat exchange module, and the cathode output terminal is connected to the input terminal of the burner.

[0072] In some embodiments, the anode exhaust gas output from the anode output terminal and the cathode exhaust gas output from the cathode output terminal of the fuel cell stack can both be used as heat sources for heat exchange in the primary heat exchange module. Optionally, the anode output terminal of the fuel cell stack is connected to the hot-side input terminal of the primary heat exchange module, and the output anode exhaust gas is used as a heat source for heat exchange in the primary heat exchange module. The anode exhaust gas after heat exchange and cooling is then output to the burner. The cathode output terminal of the fuel cell stack is connected to the input terminal of the burner, and the cathode exhaust gas is output to the burner. The burner burns and heats the input cathode exhaust gas and anode exhaust gas, and outputs high-temperature exhaust gas to the connected secondary heat exchange module.

[0073] Please see Figure 8 In some embodiments, the cathode output terminal of the heat exchange device based on a fuel cell system provided by the present invention is connected to the hot side input terminal of the first-stage heat exchange module, and the anode output terminal is connected to the input terminal of the burner.

[0074] In some embodiments, the cathode output terminal of the fuel cell stack is connected to the hot-side input terminal of the first-stage heat exchange module, and the anode output terminal is connected to the input terminal of the burner. The cathode exhaust gas output from the cathode output terminal is used as a heat source for the first-stage heat exchange module for heat exchange and cooling, and then output to the burner to combust and heat up with the anode exhaust gas. Finally, it is output to the second-stage heat exchange module through the output terminal of the burner. Since the flow rate of the cathode exhaust gas output from the cathode output terminal of the fuel cell stack is greater than that of the anode exhaust gas output from the anode output terminal, the average temperature difference of heat transfer using the cathode exhaust gas as a heat source is greater, and the temperature drop of the cathode exhaust gas is smaller, thus reducing the volume and design complexity of the first-stage heat exchange module.

[0075] The implementation of this invention provides the following beneficial effects: This embodiment provides a heat exchange device and system based on a fuel cell system. The device includes a primary heat exchange module, a burner, and a secondary heat exchange module. The hot-side input terminal of the primary heat exchange module is connected to the exhaust gas output terminal of the fuel cell stack, and the hot-side output terminal of the primary heat exchange module is connected to the input terminal of the burner. The output terminal of the burner is connected to the hot-side input terminal of the secondary heat exchange module, and the cold-side output terminal of the secondary heat exchange module is connected to the input terminal of the fuel cell stack. By setting a primary heat exchange module between the exhaust gas output terminal of the fuel cell stack and the burner, the exhaust gas temperature entering the burner is reduced, thereby reducing the combustion temperature of the burner and the output exhaust gas temperature, reducing the risk of burner overheating, and improving the operational stability of the heat exchange device. At the same time, reducing the combustion temperature of the burner and the output exhaust gas temperature reduces the heat resistance requirements of various components in the burner and heat exchange module, and reduces the implementation cost of the heat exchange device.

[0076] like Figure 9 As shown, this embodiment of the invention also provides a fuel cell system, the system including a fuel cell stack and a heat exchange network; wherein,

[0077] A fuel cell stack is used to generate electricity and produces exhaust gas.

[0078] The heat exchange network includes any of the aforementioned devices for exchanging heat with fuel based on the fuel stack exhaust gas.

[0079] The heat exchange network recovers energy from the high-temperature fuel cell stack exhaust gas, improving the energy utilization rate of the fuel cell. The heat exchange network uses the high-temperature fuel cell stack exhaust gas to reform the fuel input to the fuel cell, converting it into low-carbon materials. It also uses the high-temperature fuel cell stack exhaust gas to heat the fuel and air input to the fuel cell stack to the fuel cell stack operating temperature, thereby improving the efficiency of the fuel cell.

[0080] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A heat exchange device, characterized in that, The heat exchange device is connected to the fuel cell stack, and the device includes a primary heat exchange module, a burner, and a secondary heat exchange module; wherein... The hot-side input terminal of the primary heat exchange module is connected to the exhaust gas output terminal of the fuel cell stack, and the hot-side output terminal of the primary heat exchange module is connected to the input terminal of the burner. The output end of the burner is connected to the heat-side input end of the secondary heat exchange module; The cold-side output terminal of the secondary heat exchange module is connected to the input terminal of the fuel cell stack; wherein, the secondary heat exchange module includes a flow divider, a first heat exchanger, and a second heat exchanger.

2. The apparatus according to claim 1, characterized in that, The input end of the flow divider is connected to the output end of the burner, the first output end of the flow divider is connected to the first heat exchanger, and the second output end of the flow divider is connected to the second heat exchanger.

3. The apparatus according to claim 1, characterized in that, The secondary heat exchange module includes a third heat exchanger and a fourth heat exchanger; wherein... The hot-side input terminal of the third heat exchanger is connected to the output terminal of the burner, and the hot-side output terminal of the third heat exchanger is connected to the hot-side input terminal of the fourth heat exchanger.

4. The apparatus of claim 1, wherein, The primary heat exchange module includes an evaporator; wherein... The hot-side input terminal of the evaporator is connected to the exhaust gas output terminal of the fuel cell stack, the cold-side input terminal of the evaporator is connected to liquid water, and the hot-side output terminal of the evaporator is connected to the input terminal of the burner.

5. The apparatus of claim 1, wherein, The device further includes a pre-reformer, and the primary heat exchange module includes a gas heat exchanger; wherein... The hot-side input terminal of the gas heat exchanger is connected to the exhaust gas output terminal of the fuel cell stack, the cold-side input terminal of the gas heat exchanger is connected to the output terminal of the pre-reformer, the cold-side output terminal of the gas heat exchanger is connected to the input terminal of the fuel cell stack, and the hot-side output terminal of the gas heat exchanger is connected to the input terminal of the burner.

6. The apparatus of claim 5, wherein, The device further includes a mixer, and the secondary heat exchange module includes an air heat exchanger and an evaporator; wherein... The output end of the burner is connected to the hot side input end of the air heat exchanger and the hot side input end of the evaporator, respectively. The cold-side input terminal of the air heat exchanger is connected to an air source, and the cold-side output terminal of the air heat exchanger is connected to the input terminal of the fuel cell stack. The cold-side input terminal of the evaporator is connected to liquid water, and the cold-side output terminal of the evaporator is connected to the input terminal of the mixer; The mixer is used to mix fuel and high-temperature steam; the first input terminal of the mixer is connected to the fuel source, the second input terminal of the mixer is connected to the output terminal of the evaporator, and the output terminal of the mixer is connected to the input terminal of the pre-reformer. The pre-reformer is used to reform the fuel to obtain reformed fuel; the output of the pre-reformer is connected to the primary heat exchange module or the secondary heat exchange module.

7. The apparatus of claim 1, wherein, The exhaust gas output terminals of the fuel cell stack include an anode output terminal and a cathode output terminal.

8. The apparatus of claim 7, wherein, The anode output terminal is connected to the hot side input terminal of the primary heat exchange module, and the cathode output terminal is connected to the input terminal of the burner.

9. The apparatus according to claim 7, characterized in that, The cathode output terminal is connected to the hot-side input terminal of the primary heat exchange module, and the anode output terminal is connected to the input terminal of the burner.

10. A fuel cell system characterized by comprising: The system includes an electric fuel cell stack and a heat exchange network; wherein... The fuel cell stack is used to generate electricity and produce fuel cell exhaust gas; The heat exchange network comprises the device of any one of claims 1-9, and is used for heat exchange between the fuel and the stack tail gas.

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