An efficient heat exchange system for SOFC

Abstract

The present invention relates to a high-efficiency heat exchange system for SOFC, which includes a reforming hydrogen production system, an air source, a heat exchange system, and an electric stack. The reforming hydrogen production system is used to react to produce hydrogen-rich gas. The air source is used to provide air. The heat exchange system includes a hydrogen-rich gas inlet, an air inlet, a hydrogen-rich gas outlet, and an air outlet. The output end of the reforming hydrogen production system is connected to the hydrogen-rich gas inlet of the heat exchange system, the air source is connected to the air inlet, and the heat exchange system is used to balance the temperatures of the hydrogen-rich gas and air. The hydrogen-rich gas outlet and the air outlet are evenly connected to the electric stack, and the hydrogen-rich gas and the air react in the electric stack to generate electric energy. The high-efficiency heat exchange system for SOFC can reduce the temperature difference of the gases entering the anode and cathode of the electric stack, maintain the temperature uniformity of the gases entering the cathode and anode of the electric stack, and extend the service life of the electric stack.

Description

Technical Field

[0001] The present invention relates to a solid oxide fuel cell (SOFC), and particularly to an efficient heat exchange system for SOFC. Background Art

[0002] Solid oxide fuel cells (SOFCs) have the advantages of high energy conversion efficiency, zero pollution, and zero noise, and are considered to be the technology with the highest power generation efficiency. The stack is the core component of the SOFC to convert chemical energy into electrical energy. In order to enable the stack to operate safely and efficiently, it is crucial to control the working temperature environment at the inlet and outlet of the stack. When the stack temperature is too low, the power density of the battery cells is small and the power generation efficiency is low; when the stack temperature is too high, the temperature difference is too large, and the temperature field distribution is uneven, it will cause the sealing material to age rapidly, and the battery cells and connectors will deform or even break, resulting in a sharp decline in the performance of the stack. Therefore, it is necessary to design a reasonable SOFC thermal management system to control its working temperature reasonably and effectively. Summary of the Invention

[0003] Aiming at the above problems, the purpose of the present invention is to provide an efficient heat exchange system for SOFC, which can reduce the temperature difference between the gases entering the anode and cathode of the stack, maintain the temperature uniformity of the gases entering the cathode and anode of the stack, and extend the service life of the stack.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] An efficient heat exchange system for SOFC, comprising:

[0006] A reforming hydrogen production system, which is used to react to produce hydrogen-rich gas;

[0007] An air source, which is used to provide air;

[0008] A heat exchange system, which includes a hydrogen-rich gas inlet, an air inlet, a hydrogen-rich gas outlet, and an air outlet. The output end of the reforming hydrogen production system is connected to the hydrogen-rich gas inlet of the heat exchange system, the air source is connected to the air inlet, and the heat exchange system is used to balance the temperatures of the hydrogen-rich gas and air;

[0009] A stack, the hydrogen-rich gas outlet and the air outlet are evenly connected to the stack, and the hydrogen-rich gas and the air react in the stack to generate electric energy.

[0010] Further, the reforming hydrogen production gas system includes:

[0011] A desulfurizer, which is used to remove sulfur from the fuel;

[0012] A reformer, which is used to react the fuel after desulfurization with water to produce the hydrogen-rich gas;

[0013] A burner, which is used to provide a heat source for the reaction in the reformer.

[0014] Furthermore, it further includes a water pump and a fuel blower. The water pump is used to provide moisture for the reaction in the reformer, and the fuel blower is used to provide fuel. The fuel and the moisture react in the reformer to generate hydrogen-rich gas.

[0015] Furthermore, the heat exchange system includes an anode heat exchange module of the stack, a cathode heat exchange module of the stack, and a temperature equalization module;

[0016] The anode heat exchange module of the stack includes the hydrogen-rich gas inlet, the anode heat exchange module, the anode outlet gas inlet, and the anode outlet gas outlet;

[0017] The hydrogen-rich gas enters into the anode heat exchange module from the hydrogen-rich gas inlet;

[0018] The anode outlet gas enters into the anode heat exchange module from the anode outlet gas inlet to conduct heat exchange with the hydrogen-rich gas. The anode outlet gas is discharged from the anode outlet gas outlet, and the hydrogen-rich gas after heat exchange enters into the temperature equalization module from the hydrogen-rich gas equalizer inlet and is discharged from the hydrogen-rich gas outlet;

[0019] The cathode heat exchange module of the stack includes the air inlet, the cathode heat exchange module, the cathode outlet gas inlet, and the cathode outlet gas outlet;

[0020] The air enters into the cathode heat exchange module from the air inlet;

[0021] The cathode outlet gas enters into the cathode heat exchange module from the cathode outlet gas inlet to conduct heat exchange with the air. The cathode outlet gas is discharged from the cathode outlet gas outlet;

[0022] The air after heat exchange enters into the temperature equalization module from the air equalizer inlet and is discharged from the air outlet;

[0023] The temperature equalization module includes the hydrogen-rich gas equalizer inlet, the air equalizer inlet, the hydrogen-rich gas outlet, and the air outlet.

[0024] Furthermore, the heat exchange system further includes a temperature regulation module. The temperature regulation module includes a temperature regulation medium inlet and a temperature regulation medium outlet. The temperature regulation medium includes a temperature regulation hot medium and a temperature regulation cold medium. The temperature regulation hot medium or the temperature regulation cold medium enters into the temperature equalization module from the temperature regulation medium inlet to regulate the temperatures of the hydrogen-rich gas and the air and flows out from the temperature regulation medium outlet.

[0025] Further, the anode of the stack is communicated with the anode outlet gas inlet, and the gas that has not been fully reacted in the anode enters the anode heat exchange module from the anode outlet gas inlet to exchange heat with the hydrogen-rich gas to form a cold anode outlet gas;

[0026] The cathode of the stack is communicated with the cathode outlet gas inlet, and the gas that has not been fully reacted in the cathode enters the cathode reaction module from the cathode outlet gas to exchange heat with the air to form a cold cathode outlet gas.

[0027] Further, both the anode outlet gas outlet and the cathode outlet gas outlet are communicated with the burner, and the cold anode outlet gas and the cold cathode outlet gas enter the burner for a combustion reaction, and the generated heat is used to provide a heat source for the reformer.

[0028] Further, the fuel is natural gas.

[0029] Further, the air source is an air blower.

[0030] Due to the above technical solutions adopted by the present invention, it has the following advantages:

[0031] (1) The power generation process of the present invention integrates a "multi-in-one" heat exchange system. This system adopts the concept of multi-channel multi-stage series-parallel heat exchange, and is highly integrated and independently designed, greatly improving the heat exchange efficiency of the power generation process, and is more convenient than traditional multiple and scattered heat exchangers.

[0032] (2) The heat exchange system of the present invention includes a cathode heat exchange module and an anode heat exchange module, which has very convenient compatibility with the reforming hydrogen production system and the stack, and is provided with rich cold and hot flow interfaces, and can be friendly matched with the upstream and downstream processes.

[0033] (3) The heat exchange system of the present invention is also provided with a temperature equalization module. Its main function is to further reduce the temperature difference of the gases entering the anode and cathode of the stack, and maintain the temperature uniformity of the gases entering the cathode and anode of the stack. In addition, a flow channel for the temperature regulating medium is designed in the temperature equalization module. On the one hand, it is used to regulate the temperature of the gases entering the cathode and anode of the stack, and on the other hand, it is used for rapid heating during system startup. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0035] Figure 1 is a schematic structural diagram of the SOFC high-efficiency heat exchange system;

[0036] Figure 2 It is a schematic structural diagram of a heat exchange system. Specific Embodiments

[0037] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be completely conveyed to those skilled in the art.

[0038] An embodiment of the present invention provides a highly efficient SOFC heat exchange system, including a reforming hydrogen production system, an air source, a heat exchange system, and an electric stack. The reforming hydrogen production system is used to react to produce hydrogen-rich gas. The air source is used to provide air. The heat exchange system includes a hydrogen-rich gas inlet, an air inlet, a hydrogen-rich gas outlet, and an air outlet. The output end of the reforming hydrogen production system is connected to the hydrogen-rich gas inlet of the heat exchange system, the air source is connected to the air inlet, and the heat exchange system is used to balance the temperatures of the hydrogen-rich gas and air. The hydrogen-rich gas outlet and the air outlet are evenly connected to the electric stack, and the hydrogen-rich gas and the air react in the electric stack to generate electric energy. The highly efficient SOFC heat exchange system can reduce the temperature difference between the gases entering the anode and cathode of the electric stack, maintain the temperature uniformity of the gases entering the cathode and anode of the electric stack, and extend the service life of the electric stack.

[0039] Embodiment 1

[0040] As Figure 1 and Figure 2 shown, the highly efficient SOFC heat exchange system includes a reforming hydrogen production system 3, an air source 6, a heat exchange system 4, and an electric stack 5. The reforming hydrogen production system 3 is used to react to produce hydrogen-rich gas. The air source 6 is used to provide air. The heat exchange system 4 includes a hydrogen-rich gas inlet 4a, an air inlet 4d, a hydrogen-rich gas outlet 4c, and an air outlet 4f. The output end of the reforming hydrogen production system 3 is connected to the hydrogen-rich gas inlet 4a of the heat exchange system 4, the air source is connected to the air inlet 4d, and the heat exchange system 4 is used to balance the temperatures of the hydrogen-rich gas and air. The hydrogen-rich gas outlet 4c and the air outlet 4f are evenly connected to the electric stack 5, and the hydrogen-rich gas and the air react in the electric stack 5 to generate electric energy.

[0041] The reforming hydrogen production gas system includes a desulfurizer 3-1, a reformer 3-2, and a burner 3-3. The desulfurizer 3-1 is used to remove sulfur from the fuel; the reformer 3-2 is used to react the sulfur-removed fuel with water to produce the hydrogen-rich gas; the burner 3-3 is used to provide heat for the reaction in the reformer 3-2.

[0042] The SOFC high-efficiency heat exchange system further includes a water pump 1 and a fuel blower 2. The water pump 1 is used to provide moisture for the reaction in the reformer 3-2, and the fuel blower 2 is used to provide fuel. The fuel and the moisture react in the reformer 3-2 to generate hydrogen-rich gas.

[0043] The fuel is preferably natural gas.

[0044] The air source is preferably an air blower.

[0045] The heat exchange system 4 includes an anode heat exchange module of the stack, a cathode heat exchange module of the stack, and a temperature equalization module 4-3;

[0046] The anode heat exchange module of the stack includes the hydrogen-rich gas inlet 4a, the anode heat exchange module 4-1, the anode outlet gas inlet 4g, and the anode outlet gas outlet 4h;

[0047] The hydrogen-rich gas enters the anode heat exchange module 4-1 from the hydrogen-rich gas inlet 4a;

[0048] The anode outlet gas enters the anode heat exchange module 4-1 from the anode outlet gas inlet 4g and exchanges heat with the hydrogen-rich gas. The anode outlet gas is discharged from the anode outlet gas outlet 4h, and the hydrogen-rich gas after heat exchange enters the temperature equalization module 4-3 from the hydrogen-rich gas equalizer inlet 4b and is discharged from the hydrogen-rich gas outlet 4c;

[0049] The cathode heat exchange module of the stack includes the air inlet 4d, the cathode heat exchange module 4-2, the cathode outlet gas inlet 4i, and the cathode outlet gas outlet 4j;

[0050] The air enters the cathode heat exchange module from the air inlet 4d;

[0051] The cathode outlet gas enters the cathode heat exchange module 4-2 from the cathode outlet gas inlet 4i and exchanges heat with the air. The cathode outlet gas is discharged from the cathode outlet gas outlet 4j;

[0052] The air after heat exchange enters the temperature equalization module 4-3 from the air equalizer inlet 4e and is discharged from the air outlet 4f;

[0053] The temperature equalization module 4-3 includes the hydrogen-rich gas equalizer inlet 4b, the air equalizer inlet 4e, the hydrogen-rich gas outlet 4c, and the air outlet 4f.

[0054] The heat exchange system further includes a temperature adjustment module, which includes a temperature adjustment medium inlet 4k and a temperature adjustment medium outlet 4l. The temperature adjustment medium includes a heat temperature adjustment medium and a cold temperature adjustment medium. The heat temperature adjustment medium or the cold temperature adjustment medium enters the temperature equalization module 4-3 from the temperature adjustment medium inlet 4k to adjust the temperatures of the hydrogen-rich gas and the air, and flows out from the temperature adjustment medium outlet 4l.

[0055] When the temperatures of the hydrogen-rich gas and the air after heat exchange are lower than the temperature required by the fuel cell stack 5 after passing through the temperature equalization module 4-3, a heat temperature adjustment medium is introduced into the temperature equalization module 4-3 to further heat the temperatures of the hydrogen-rich gas and the air after heat exchange to reach the temperature required by the fuel cell stack 5.

[0056] When the hydrogen-rich gas from the anode heat exchange module 4-1 and the air from the cathode heat exchange module 4-2 enter the temperature equalization module 4-3 for sufficient temperature balance, and are higher than the inlet temperature requirements of the cathode 5-3 and the anode 5-1 of the fuel cell stack. At this time, a cold temperature adjustment medium needs to be introduced into the temperature equalization module 4-3 to cool the hydrogen-rich gas and the air, so as to meet the inlet temperature requirements of the cathode 5-3 and the anode 5-1 of the fuel cell stack.

[0057] When the hydrogen-rich gas from the anode heat exchange module 4-1 and the air from the cathode heat exchange module 4-2 enter the temperature equalization module 4-3 for sufficient temperature balance, and already meet the inlet temperature requirements of the cathode 5-3 and the anode 5-1 of the fuel cell stack. At this time, there is no need to introduce a temperature adjustment medium.

[0058] The anode 5-1 of the fuel cell stack 5 is communicated with the anode outlet gas inlet 4g. The gas that has not fully reacted in the anode 5-1 enters the anode heat exchange module from the anode outlet gas inlet 4g and exchanges heat with the hydrogen-rich gas to form a cold anode outlet gas.

[0059] The cathode 5-3 of the fuel cell stack 5 is communicated with the cathode outlet gas inlet 4i. The gas that has not fully reacted in the cathode 5-3 enters the cathode reaction module from the cathode outlet gas inlet 4i and exchanges heat with the air to form a cold cathode outlet gas.

[0060] The anode outlet gas outlet 4h and the cathode outlet gas outlet 4j are both communicated with the burner 3-3. The cold anode outlet gas and the cold cathode outlet gas enter the burner 3-3 for a combustion reaction, and the generated heat is used to provide a heat source for the reformer 3-2.

[0061] The working principle of the above SOFC high-efficiency heat exchange system is as follows:

[0062] Water from outside the boundary is pressurized by the water pump 1 and then enters the reformer 3-2 in the reforming hydrogen production system 3. Natural gas from outside the boundary is pressurized by the fuel blower 2 and then enters the desulfurizer 3-1 in the reforming hydrogen production system 3 for desulfurization. The sulfur content is reduced to below 0.05 ppm and then enters the reformer 3-2.

[0063] The desulfurized natural gas and water undergo a chemical reaction under the action of a catalyst to generate hydrogen, carbon monoxide, and carbon dioxide. The heat source required for natural gas reforming to produce hydrogen mainly comes from the combustion of the anode outlet gas of the stack in the burner 3-3.

[0064] The hydrogen-rich gas after reforming enters the anode heat exchange module 4-1 in the multi-functional heat exchange system 4 through the hydrogen-rich gas inlet 4a and exchanges heat with the anode outlet gas of the stack. The heated hydrogen-rich gas enters the temperature equalization module 4-3 through the hydrogen-rich gas equalizer inlet 4b and equalizes the temperature with the heated air and the conditioning medium. Then, after coming out from the hydrogen-rich gas outlet 4c, it enters the anode 5-1 in the stack to convert chemical energy into electrical energy.

[0065] Air is pressurized by the air blower and then enters the cathode heat exchange module 4-2 in the heat exchange system 4 through the air inlet 4d, exchanges heat with the high-temperature air from the cathode outlet, and then enters the temperature equalizer 4-3 through the air equalizer inlet 4e to equalize the temperature with the hot hydrogen-rich gas and the temperature control medium. The air after equalization leaves the heat exchange module from the air outlet 4f and then enters the cathode 5-3 of the stack.

[0066] The anode outlet gas after the reaction in the anode 5-1 of the stack enters the anode heat exchange module 4-1 from the anode outlet gas inlet port 4g, serves as a heat source to exchange heat with the hydrogen-rich gas, and then leaves the heat exchange module from the anode outlet gas outlet 4h and enters the burner 3-3 in the reforming hydrogen production system 3. The unreacted combustible components such as CO, H2, and CH4 in the gas are fully combusted with the cathode outlet air in the burner 3-3 to provide the required heat for the reformer 3-2.

[0067] Oxygen in the air gains electrons and undergoes an electrochemical reaction to dissociate into O 2- ions, enters the anode 5-1 of the stack through the electrolyte 5-2, reacts with H2 and CO to generate H2O and CO2, and at the same time releases electrons to complete the power generation process and output electrical energy externally. The air that has not reacted in the cathode 5-3 of the stack takes out heat, enters the cathode heat exchange module 4-2 in the heat exchange system 4 through the cathode outlet gas inlet 4i, heats the air pressurized by the air blower, and then leaves the heat exchange system from the cathode outlet gas outlet 4j and enters the burner 3-3 to fully combust with the unreacted anode outlet gas of the stack to provide heat for the reforming hydrogen production system 3.

[0068] This power generation process integrates a "multi-in-one" heat exchange system. This system adopts the concept of multi-channel multi-stage series-parallel heat exchange, with a highly integrated independent design, greatly improving the heat exchange efficiency of the power generation process and being more convenient than traditional multiple and scattered heat exchangers. This heat exchange system includes a cathode heat exchange module and an anode heat exchange module, which has very convenient compatibility with the reforming hydrogen production system and the fuel cell stack. It is equipped with rich cold and hot fluid interfaces and can be well matched with the upstream and downstream processes. This heat exchange system also has a temperature equalization module. Its main function is to further reduce the gas temperature difference between the anode and cathode entering the fuel cell stack and maintain the temperature uniformity of the gas entering the cathode and anode of the fuel cell stack. In addition, a flow channel for the temperature control medium is designed in the temperature equalization module. On the one hand, it is used to regulate the temperature of the gas entering the cathode and anode of the fuel cell stack, and on the other hand, it is used for rapid heating during system startup.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An efficient heat exchange system for SOFC, characterized in that, Comprising: A reforming hydrogen production system for reacting to produce hydrogen-rich gas; An air source for providing air; A heat exchange system including a hydrogen-rich gas inlet, an air inlet, a hydrogen-rich gas outlet, and an air outlet. The output end of the reforming hydrogen production system is connected to the hydrogen-rich gas inlet of the heat exchange system, the air source is connected to the air inlet, and the heat exchange system is used to balance the temperatures of the hydrogen-rich gas and air; A fuel cell stack. The hydrogen-rich gas outlet and the air outlet are both connected to the fuel cell stack, and the hydrogen-rich gas and the air react in the fuel cell stack to generate electric energy; The reforming hydrogen production system includes: A desulfurizer for removing sulfur from the fuel; A reformer for reacting the desulfurized fuel with water to produce the hydrogen-rich gas; A burner for providing a heat source for the reaction in the reformer; It further includes a water pump and a fuel blower. The water pump is used to provide moisture for the reaction in the reformer, and the fuel blower is used to provide fuel. The fuel and the moisture react in the reformer to generate hydrogen-rich gas; The heat exchange system includes an anode heat exchange module of the fuel cell stack, a cathode heat exchange module of the fuel cell stack, and a temperature equalization module; The anode heat exchange module of the fuel cell stack includes the hydrogen-rich gas inlet, the anode heat exchange module, an anode outlet gas inlet, and an anode outlet gas outlet; The hydrogen-rich gas enters the anode heat exchange module from the hydrogen-rich gas inlet; The anode outlet gas enters the anode heat exchange module from the anode outlet gas inlet to exchange heat with the hydrogen-rich gas. The anode outlet gas is discharged from the anode outlet gas outlet, and the hydrogen-rich gas after heat exchange enters the temperature equalization module from the hydrogen-rich gas equalizer inlet and is discharged from the hydrogen-rich gas outlet; The cathode heat exchange module of the fuel cell stack includes the air inlet, the cathode heat exchange module, a cathode outlet gas inlet, and a cathode outlet gas outlet; The air enters the cathode heat exchange module from the air inlet; The cathode outlet gas enters the cathode heat exchange module from the cathode outlet gas inlet to exchange heat with the air, and the cathode outlet gas is discharged from the cathode outlet gas outlet; The air after heat exchange enters the temperature equalization module from the air equalizer inlet and is discharged from the air outlet; The temperature equalization module includes the hydrogen-rich gas equalizer inlet, the air equalizer inlet, the hydrogen-rich gas outlet, and the air outlet; The heat exchange system further includes a temperature adjustment module. The temperature adjustment module includes a temperature adjustment medium inlet and a temperature adjustment medium outlet. The temperature adjustment medium includes a temperature adjustment hot medium and a temperature adjustment cold medium. The temperature adjustment hot medium or the temperature adjustment cold medium enters the temperature equalization module from the temperature adjustment medium inlet to adjust the temperatures of the hydrogen-rich gas and air and flows out from the temperature adjustment medium outlet.

2. The SOFC high-efficiency heat exchange system according to claim 1, wherein The anode of the fuel cell stack is communicated with the anode outlet gas inlet, and the gas that has not been completely reacted in the anode enters the anode heat exchange module from the anode outlet gas inlet to exchange heat with the hydrogen-rich gas to form a cold anode outlet gas; The cathode of the stack is communicated with the cathode outlet gas inlet, and the gas that has not been fully reacted in the cathode enters the cathode reaction module from the cathode outlet gas inlet to exchange heat with the air to form cold cathode outlet gas.

3. The SOFC high-efficiency heat exchange system according to claim 2, characterized in that The anode outlet gas outlet and the cathode outlet gas outlet are both communicated with the burner, and the cold anode outlet gas and the cold cathode outlet gas enter the burner for a combustion reaction, and the generated heat is used to provide a heat source for the reformer.

4. The SOFC high-efficiency heat exchange system according to claim 1, wherein The fuel is natural gas.

5. The SOFC high-efficiency heat exchange system according to claim 1, characterized in that The air source is an air blower.

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