Stack unit and solid oxide fuel cell

Abstract

The application discloses a kind of electric pile unit and solid oxide fuel cell, electric pile unit includes the air distribution plate, fuel preheating plate, fuel distribution plate and single cell plate arranged in laminated sequence, multiple cold fuel inlets and multiple preheated fuel outlets are opened in the first end of electric pile unit, multiple tail gas outlets are opened in the second end of electric pile unit;Multiple preheating flow channels and multiple fuel distribution flow channels are respectively opened on the surface of fuel preheating plate and fuel distribution plate facing each other;Part of the number of preheating flow channels is communicated with corresponding cold fuel inlet, the rest number of preheating flow channels is communicated with the first end of multiple fuel distribution flow channels by corresponding preheated fuel outlet, the second end of multiple fuel distribution flow channels is communicated with multiple tail gas outlets.The application can effectively utilize the heat inside the electric pile, reduce the parasitic power of air blower, and improve the service life of solid oxide fuel cell.

Description

Technical Field

[0001] This invention relates to the field of fuel cells, and more particularly to a fuel cell stack unit and a solid oxide fuel cell. Background Technology

[0002] Currently, renewable energy sources, such as photovoltaics and wind power, account for an increasingly large proportion of electricity generation. Their volatility places extremely high demands on energy storage technologies. Utilizing surplus electricity to electrolyze water to produce hydrogen has become a recognized solution for large-scale, long-term energy storage. The produced hydrogen can be used in transportation, chemical, and metallurgical industries, but the storage and transportation technologies for hydrogen are very demanding. Solid oxide fuel cells (SOFCs) can efficiently convert hydrogen into electricity on-site, supplementing grid demand during periods of insufficient wind power or rainy weather, making them a promising technological approach. SOFCs operate at high temperatures, have fast electrode reaction rates, and low polarization, resulting in significantly higher power generation efficiency than other types of fuel cells, and far exceeding that of internal combustion engines.

[0003] However, SOFCs also present some challenges when using hydrogen fuel for power generation. One such challenge is the high current density and significant Joule heat release within the fuel cell stack, leading to difficulties in thermal management. Traditional methods utilize a large air excess ratio, injecting a large volume of air into the stack to remove this Joule heat. This results in high parasitic power consumption from the air blower, impacting system efficiency. Furthermore, the heat removed from the stack is not effectively utilized, leading to energy waste. Summary of the Invention

[0004] The purpose of this invention is to provide a fuel cell stack unit and a solid oxide fuel cell that can effectively utilize the heat inside the fuel cell stack, reduce the parasitic power of the air blower, and improve the service life of the solid oxide fuel cell.

[0005] The objective of this invention can be achieved using the following technical solutions: This invention provides a fuel cell stack unit for a solid oxide fuel cell. Each stack unit includes an air distribution plate, a fuel preheating plate, a fuel distribution plate, and a single cell plate arranged in a stacked sequence. Multiple cold fuel inlets and multiple preheated fuel outlets are provided at the first end of the stack unit, and multiple exhaust gas outlets are provided at the second end. Multiple preheating channels and multiple fuel distribution channels are respectively formed on the back-to-back surfaces of the fuel preheating plate and the fuel distribution plate. A portion of the preheating channels are connected to their corresponding cold fuel inlets, while the remaining preheating channels are connected to the first ends of the multiple fuel distribution channels via their corresponding preheated fuel outlets. The second ends of the multiple fuel distribution channels are connected to the multiple exhaust gas outlets.

[0006] In a preferred embodiment of the present invention, the plurality of preheating channels include a plurality of inlet preheating channels and a plurality of outlet preheating channels arranged in parallel and staggered manner. The first ends of the plurality of inlet preheating channels are respectively connected to a plurality of cold fuel inlets, the first ends of the plurality of outlet preheating channels are respectively connected to a plurality of preheated fuel outlets, and the second ends of the plurality of inlet preheating channels are connected to the second ends of the plurality of outlet preheating channels.

[0007] In a preferred embodiment of the invention, the amount of cold fuel inlet is greater than the amount of preheated fuel outlet.

[0008] In a preferred embodiment of the present invention, the number of cold fuel inlets is three, and the number of preheated fuel outlets is two.

[0009] In a preferred embodiment of the present invention, the air distribution plate is provided with a plurality of air distribution channels, and each group of fuel cell stack units also includes a plurality of air inlets and a plurality of air outlets, with the two ends of the plurality of air distribution channels respectively connected to the plurality of air inlets and the plurality of air outlets.

[0010] In a preferred embodiment of the present invention, both the preheating channel and the air distribution channel are straight channels, and the length direction of the air distribution channel is perpendicular to the length direction of the preheating channel.

[0011] In a preferred embodiment of the present invention, a plurality of first feed holes and a plurality of first discharge holes are provided at the first end of the air distribution plate, and a plurality of first exhaust holes are provided at the second end of the air distribution plate; a plurality of second feed holes and a plurality of second discharge holes are provided at the first end of the fuel preheating plate, and a plurality of second exhaust holes are provided at the second end of the fuel preheating plate; a plurality of third feed holes and a plurality of third discharge holes are provided at the first end of the fuel distribution plate, and a plurality of third exhaust holes are provided at the second end of the fuel distribution plate; a plurality of... The system includes a fourth feed port and multiple fourth discharge ports, with multiple fourth exhaust ports provided at the second end of the single solar panel. Multiple first feed ports, multiple second feed ports, multiple third feed ports, and multiple fourth feed ports are arranged vertically opposite each other to form multiple cold fuel inlets. Multiple first discharge ports, multiple second discharge ports, multiple third discharge ports, and multiple fourth discharge ports are arranged vertically opposite each other to form multiple preheated fuel outlets. Multiple first exhaust ports, multiple second exhaust ports, multiple third exhaust ports, and multiple fourth exhaust ports are arranged vertically opposite each other to form multiple exhaust outlets.

[0012] In a preferred embodiment of the present invention, a plurality of first air inlets and a plurality of first air outlets are respectively provided on both sides of the air distribution plate, a plurality of second air inlets and a plurality of second air outlets are respectively provided on both sides of the fuel preheating plate, a plurality of third air inlets and a plurality of third air outlets are respectively provided on both sides of the fuel distribution plate, and a plurality of fourth air inlets and a plurality of fourth air outlets are provided on the single battery plate; the plurality of first air inlets, the plurality of second air inlets, the plurality of third air inlets and the plurality of fourth air outlets are arranged vertically opposite each other to form a plurality of air inlets, and the plurality of first air outlets, the plurality of second air outlets, the plurality of third air outlets and the plurality of fourth air outlets are arranged vertically opposite each other to form a plurality of air outlets.

[0013] In a preferred embodiment of the present invention, the air distribution plate, the fuel preheating plate, and the fuel distribution plate are welded together to form an integrated connecting plate.

[0014] In a preferred embodiment of the present invention, the fuel preheating plate and the fuel distribution plate are the upper and lower parts of the same plate body, and the preheating flow channel and the fuel distribution flow channel are formed on opposite side plates of the plate body.

[0015] In a preferred embodiment of the present invention, a first sealing gasket ring is provided between the fuel distribution plate and the single battery plate. The first sealing gasket ring is provided with a plurality of fifth feed holes, a plurality of fifth discharge holes, a plurality of third exhaust holes, a plurality of third air inlets and a plurality of third air outlets, which are respectively directly opposite to and connected to a plurality of third feed holes, a plurality of third discharge holes, a plurality of third exhaust holes, a plurality of third air inlets and a plurality of third air outlets.

[0016] In a preferred embodiment of the present invention, a second sealing gasket ring is provided on the side of the air distribution plate facing away from the fuel preheating plate. The second sealing gasket ring is provided with a plurality of sixth feed holes, a plurality of sixth discharge holes, a plurality of second exhaust holes, a plurality of second air inlets and a plurality of second air outlets, which are respectively directly opposite to and connected to a plurality of second feed holes, a plurality of second discharge holes, a plurality of second exhaust holes, a plurality of second air inlets and a plurality of second air outlets.

[0017] In a preferred embodiment of the present invention, the cold fuel inlet is used to introduce hydrogen fuel at a temperature of 400°C-500°C.

[0018] The present invention also provides a solid oxide fuel cell, comprising a plurality of stack units as described above, stacked sequentially.

[0019] In a preferred embodiment of the present invention, the solid oxide fuel cell further includes a top plate, a bottom plate, a feed manifold, a tail gas manifold, an intake manifold, and an outlet manifold, with multiple stack units sandwiched between the top plate and the bottom plate; the feed manifold, tail gas manifold, intake manifold, and outlet manifold are connected to one of the top plate and the bottom plate, the feed manifold can be connected to multiple cold fuel inlets, the tail gas manifold can be connected to multiple tail gas outlets, the intake manifold can be connected to multiple air inlets, and the outlet manifold can be connected to multiple air outlets.

[0020] In a preferred embodiment of the present invention, a third sealing gasket ring is provided between the base plate and the single battery panel in the stack unit near the base plate.

[0021] In a preferred embodiment of the present invention, the first sealing ring, the second sealing ring, and the third sealing ring are made of mica or glass ceramic.

[0022] As described above, the fuel cell stack unit and solid oxide fuel cell of the present invention, by setting a preheating channel within the stack unit, utilize the high thermal conductivity of hydrogen fuel to allow the relatively low-temperature hydrogen fuel to directly enter the stack. The hydrogen fuel absorbs heat within the stack, thereby heating itself to the battery operating temperature. This not only effectively utilizes the thermal energy of the stack but also significantly reduces the air-fuel ratio, thereby decreasing the parasitic power of the air blower and improving the overall system efficiency. Simultaneously, since the cold fuel inlet and the preheated fuel outlet are located on the same side, the fuel can flow back and forth within the preheating channel, increasing the preheating length and enhancing the heat transfer effect. Furthermore, by placing the cold fuel and preheated fuel on the same side, while the high-temperature exhaust gas after power generation is on the opposite side, thermal stress can be minimized, preventing battery breakage due to excessive thermal stress and effectively improving battery life. Attached Figure Description

[0023] The following figures are intended only to illustrate and explain the present invention and do not limit the scope of the invention. Wherein: Figure 1 This is a schematic diagram showing the disassembly of each plate in the fuel cell stack unit provided by the present invention.

[0024] Figure 2 This is a schematic diagram of the structure of the fuel stack unit provided by the present invention after the air distribution plate, fuel preheating plate and fuel distribution plate are welded into an integrated connecting plate.

[0025] Figure 3 This is a schematic diagram of the air distribution plate provided by the present invention.

[0026] Figure 4 This is a schematic diagram of the fuel preheating plate provided by the present invention.

[0027] Figure 5 This is a schematic diagram of the fuel distribution plate provided by the present invention.

[0028] Figure 6 This is a schematic diagram of a single battery panel provided by the present invention.

[0029] Figure 7 A schematic diagram of the first sealing ring provided by the present invention.

[0030] Figure 8 A schematic diagram of the second sealing ring provided by the present invention.

[0031] Figure 9 A schematic diagram of the third sealing ring provided by the present invention.

[0032] Explanation of icon numbers: 100. Fuel stack unit; 101. Cold fuel inlet; 102. Preheated fuel outlet; 103. Exhaust gas outlet; 104. Air inlet; 105. Air outlet; 1. Air distribution plate; 11. Air distribution channel; 111. First end; 112. Second end; 12. First feed hole; 13. First discharge hole; 14. First exhaust hole; 15. First air inlet; 151. First air inlet connection channel; 16. First air outlet; 161. First air outlet connection channel; 17. First groove; 18. First rib; 2. Fuel preheating plate; 21. Preheating channel; 211. Inlet preheating channel; 212. Outlet preheating channel; 22. Second feed hole; 221. First feed connection channel; 23. Second discharge hole; 231. First discharge connection channel; 24. Second exhaust hole; 25. Second air inlet; 26. Second air outlet; 27. Second groove; 28. Second rib; 3. Fuel distribution plate; 31. Fuel distribution channel; 32. Third feed hole; 33. Third discharge hole; 331. Second discharge connection channel; 34. Third exhaust port; 341. First exhaust connection channel; 35. Third air inlet; 36. Third air outlet; 37. Third groove; 38. Third rib; 4. Single solar panel; 41. Fourth feed port; 42. Fourth discharge port; 43. Fourth exhaust port; 44. Fourth air inlet port; 45. Fourth exhaust port; 5. First sealing gasket ring; 51. Fifth feed hole; 52. Fifth discharge hole; 521. Third discharge connection channel; 53. Fifth exhaust port; 531. Second exhaust connection channel; 54. Fifth air inlet; 55. Fifth air outlet; 6. Second sealing gasket ring; 61. Sixth feed hole; 62. Sixth discharge hole; 63. Sixth exhaust hole; 64. Sixth air inlet; 641. Second air inlet connection channel; 65. Sixth air outlet; 651. Second air outlet connection channel; 7. Third sealing gasket ring; 71. Seventh feed hole; 72. Seventh discharge hole; 73. Seventh exhaust hole; 74. Seventh air inlet hole; 75. Seventh air outlet hole. Detailed Implementation

[0033] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0034] like Figures 1 to 9 As shown, this application provides a fuel cell stack unit 100 for a solid oxide fuel cell. Each fuel cell stack unit 100 includes an air distribution plate 1, a fuel preheating plate 2, a fuel distribution plate 3, and a single cell plate 4 arranged in a stacked sequence. A plurality of cold fuel inlets 101 and a plurality of preheated fuel outlets 102 are provided at the first end of the fuel cell stack unit 100, and a plurality of exhaust gas outlets 103 are provided at the second end of the fuel cell stack unit 100. A plurality of preheating channels 21 and a plurality of fuel distribution channels 31 are respectively provided on the surfaces of the fuel preheating plate 2 and the fuel distribution plate 3 facing away from each other. A portion of the preheating channels 21 are connected to the corresponding cold fuel inlets 101, and the remaining portion of the preheating channels 21 are connected to the first ends of the plurality of fuel distribution channels 31 through the corresponding preheated fuel outlets 102. The second ends of the plurality of fuel distribution channels 31 are connected to the plurality of exhaust gas outlets 103.

[0035] Multiple preheating channels 21 and multiple fuel distribution channels 31 are arranged at intervals. The length directions of the preheating channels 21 and the fuel distribution channels 31 are both along the length direction of the fuel cell stack unit 100. The first end and the second end of the fuel cell stack unit 100 are opposite ends along the length direction of the fuel cell stack unit 100, respectively. Multiple cold fuel inlets 101 and multiple preheated fuel outlets 102 are all located at the first end of the fuel cell stack unit 100, and multiple exhaust gas outlets 103 are all located at the second end of the fuel cell stack unit 100. This allows these fuel-related openings (including cold fuel inlets 101 and preheated fuel outlets 102) and exhaust gas outlets 103 to be located at opposite ends of the fuel cell stack unit 100, respectively.

[0036] During operation, cold fuel enters the preheating channel 21 through the cold fuel inlet 101. After absorbing heat and being preheated inside the stack unit 100, the preheated fuel enters the fuel distribution channel 31 through the fuel outlet 102, where it is distributed on the anode surface of the single battery panel 4 and generates electricity. The exhaust gas is discharged through the exhaust gas outlet 103.

[0037] Therefore, the fuel cell stack unit 100 of this application, by setting a preheating channel 21 within the stack unit 100, utilizes the high thermal conductivity of hydrogen fuel, allowing the relatively low-temperature hydrogen fuel to directly enter the stack and absorb heat inside, thereby heating itself to the battery operating temperature. This not only effectively utilizes the thermal energy of the stack but also significantly reduces the air-fuel ratio, thereby decreasing the parasitic power of the air blower and improving the overall system efficiency. Simultaneously, since the cold fuel inlet 101 and the preheated fuel outlet 102 are located on the same side, the fuel can flow back and forth within the preheating channel 21, increasing the preheating length and enhancing the heat transfer effect. Furthermore, by placing the cold fuel and preheated fuel on the same side, while the high-temperature exhaust gas after power generation is on the opposite side, thermal stress can be minimized, preventing battery breakage due to excessive thermal stress and effectively improving battery life.

[0038] Specifically, the operating temperature of a solid oxide fuel cell (SOFC) is 600℃-800℃. The aforementioned cold fuel inlet 101 is used to introduce hydrogen fuel (i.e., cold fuel) at a temperature of 400℃-500℃. The preheating channel 21 provided in the stack unit 100 allows the hydrogen fuel to enter the stack at a temperature far below the battery's operating temperature. Within the stack, it conducts heat and absorbs heat to reach the battery's operating temperature, thus generating electricity. Because the SOFC structure is flexible and its operating temperature is very high, and the material of the single cell panel 4 is mainly ceramic, significant thermal stress in the SOFC can easily cause the cell to break. Therefore, the design described in this application minimizes thermal stress and is well-suited for solid oxide fuel cells, preventing damage due to high thermal stress.

[0039] In practical applications, hydrogen fuel can be heated to 400℃-500℃ via external auxiliary heating, and its temperature after heat exchange in the preheating channel 21 is 650℃-750℃. It is understandable that when a solid oxide fuel cell first starts operating, the internal heat of the stack is still relatively low. The temperature of the hydrogen fuel entering the fuel distribution channel 31 after preheating may not yet reach 650℃-750℃, but it can still generate electricity, albeit at a low efficiency. After the fuel cell has been operating for a while, the internal heat of the stack can be used to preheat the hydrogen fuel to a higher temperature.

[0040] In some alternative embodiments, refer to Figure 4 The multiple preheating channels 21 include multiple inlet preheating channels 211 and multiple outlet preheating channels 212 arranged in parallel and staggered. The first ends of the multiple inlet preheating channels 211 are respectively connected to multiple cold fuel inlets 101, the first ends of the multiple outlet preheating channels 212 are respectively connected to multiple preheated fuel outlets 102, and the second ends of the multiple inlet preheating channels 211 and the second ends of the multiple outlet preheating channels 212 are interconnected.

[0041] In each fuel cell stack unit 100, the number of inlet preheating channels 211 is the same as the number of cold fuel inlets 101, the number of outlet preheating channels 212 is the same as the number of preheated fuel outlets 102, and the number of fuel distribution channels 31 is greater than the number of preheating channels 21. The first and second ends of the preheating channels 21 are opposite ends along the length of the fuel cell stack unit 100, and the first and second ends of the fuel distribution channels 31 are opposite ends along the length of the fuel cell stack unit 100. The second ends of the multiple preheating channels 21 are interconnected, the first ends of the multiple fuel distribution channels 31 are interconnected and connected to the multiple preheated fuel outlets 102, and the second ends of the multiple fuel distribution channels 31 are interconnected and connected to the multiple exhaust gas outlets 103.

[0042] By staggering the arrangement of multiple inlet preheating channels 211 and multiple outlet preheating channels 212, the fuel can be distributed more evenly within the multiple fuel distribution channels 31, improving the battery's power generation efficiency, temperature distribution uniformity, and stress distribution uniformity. Simultaneously, after entering through the inlet preheating channel 211, the hydrogen fuel flows out through the adjacent outlet preheating channel 212. The multiple preheating channels 21 form a reciprocating structure, effectively increasing the preheating length and enhancing the preheating effect.

[0043] Optionally, the number of cold fuel inlets 101 is greater than the number of preheated fuel outlets 102, which can create a certain resistance to the flow of hydrogen fuel in the preheating channel 21, increase the residence time of hydrogen fuel in the preheating channel 21, and improve the preheating efficiency.

[0044] The specific number of preheating channels 21, cold fuel inlets 101, and preheated fuel inlets in the fuel cell stack unit 100 can be determined based on the actual product size and performance requirements. For example, in a specific example, refer to... Figure 4 There are three cold fuel inlets 101 and two preheated fuel outlets 102. Correspondingly, there are five preheating channels 21, with three inlet preheating channels 211 and two outlet preheating channels 212.

[0045] This example employs a three-inlet, two-outlet configuration, with the cold fuel inlet 101 and the preheating fuel outlet designed on the same side. After the cold fuel enters, it absorbs heat from the hot air (i.e., the hot air generated by the increased air temperature in the air distribution channel 11 during battery operation) in the preheating channel 21, thus achieving preheating. Because the return channel is twice the length of the current-generating channel (i.e., the fuel distribution channel 31), the preheating effect is significant. Finally, the preheated fuel exits from... Figure 4 The fuel distribution channel 31 shown on the left goes out and then turns into the back for power generation; it realizes the working sequence of hydrogen fuel being preheated inside the stack and then turned back, then generating electricity and being discharged from the stack, realizing internal heat exchange of hydrogen fuel and improving the uniformity of fuel distribution.

[0046] Furthermore, refer to Figure 3 The air distribution plate 1 has multiple air distribution channels 11. Each group of fuel cell stack units 100 also includes multiple air inlets 104 and multiple air outlets 105. The two ends of the multiple air distribution channels 11 are respectively connected to the multiple air inlets 104 and the multiple air outlets 105.

[0047] Multiple air distribution channels 11 are arranged at intervals. Generally, the first ends 111 of the multiple air distribution channels 11 are interconnected and all are connected to multiple air inlets 104. The second ends 112 of the multiple air distribution channels 11 are interconnected and all are connected to multiple air outlets 105. The number of air distribution channels 11 is greater than the number of preheating channels 21. During operation, air enters each air distribution channel 11 through each air inlet 104 and then flows out through the air outlet 105. During this process, the air is heated to hot air due to the large amount of Joule heat released inside the fuel cell stack, which can preheat the hydrogen fuel in the preheating channel 21.

[0048] Optionally, both the preheating channel 21 and the air distribution channel 11 are straight channels, and the length direction of the air distribution channel 11 is perpendicular to the length direction of the preheating channel 21. The air distribution channel 11 and the fuel distribution channel 31 are perpendicular to each other, forming a cross-flow pattern, which can better ensure that air and hydrogen fuel do not interfere with each other and prevent mixed gas from occurring. The two ends of the air distribution channel 11 are opposite ends along the length direction of the air distribution channel 11. When the air distribution channel 11 is arranged perpendicular to the fuel distribution channel 31, the two ends of the air distribution channel 11 are also opposite ends along the width direction of the fuel cell unit 100.

[0049] In some optional embodiments, to facilitate the processing and arrangement of the cold fuel inlet 101, the preheated fuel outlet 102, the exhaust gas outlet 103, the air inlet 104, and the air outlet 105, refer to Figures 3 to 6 Multiple first feed holes 12 and multiple first discharge holes 13 are provided at the first end of the air distribution plate 1, and multiple first exhaust holes 14 are provided at the second end of the air distribution plate 1; multiple second feed holes 22 and multiple second discharge holes 23 are provided at the first end of the fuel preheating plate 2, and multiple second exhaust holes 24 are provided at the second end of the fuel preheating plate 2; multiple third feed holes 32 and multiple third discharge holes 33 are provided at the first end of the fuel distribution plate 3, and multiple third exhaust holes 34 are provided at the second end of the fuel distribution plate 3; multiple fourth feed holes 41 and multiple fourth discharge holes 42 are provided at the first end of the single battery plate 4, and multiple fourth exhaust holes 43 are provided at the second end of the single battery plate 4.

[0050] Multiple first feed holes 12, multiple second feed holes 22, multiple third feed holes 32 and multiple fourth feed holes 41 are arranged vertically opposite each other to form multiple cold fuel inlets 101; multiple first discharge holes 13, multiple second discharge holes 23, multiple third discharge holes 33 and multiple fourth discharge holes 42 are arranged vertically opposite each other to form multiple preheated fuel outlets 102; and multiple first exhaust gas holes 14, multiple second exhaust gas holes 24, multiple third exhaust gas holes 34 and multiple fourth exhaust gas holes 43 are arranged vertically opposite each other to form multiple exhaust gas outlets 103.

[0051] Multiple first air inlets 15 and multiple first air outlets 16 are respectively opened on both sides of the air distribution plate 1. Multiple second air inlets 25 and multiple second air outlets 26 are respectively opened on both sides of the fuel preheating plate 2. Multiple third air inlets 35 and multiple third air outlets 36 are respectively opened on both sides of the fuel distribution plate 3. Multiple fourth air inlets 44 and multiple fourth air outlets 45 are opened on the single battery plate 4. The multiple first air inlets 15, multiple second air inlets 25, multiple third air inlets 35 and multiple fourth air inlets 44 are arranged vertically opposite each other to form multiple air inlets 104. The multiple first air outlets 16, multiple second air outlets 26, multiple third air outlets 36 and multiple fourth air outlets 45 are arranged vertically opposite each other to form multiple air outlets 105.

[0052] Among them, the air distribution plate 1, fuel preheating plate 2, fuel distribution plate 3, and single battery plate 4 are all rectangular plates of the same size. The two ends of the air distribution plate 1, fuel preheating plate 2, fuel distribution plate 3, and single battery plate 4 refer to the two ends along the length direction of the rectangular plate, and the two sides of each plate refer to the two sides along the width direction of the rectangular plate. The two ends and two sides of each plate are in the same orientation as the two ends and two sides of the fuel cell stack unit 100, respectively. The number of first feed holes 12, second feed holes 22, third feed holes 32 and fourth feed holes 41 are the same; the number of first discharge holes 13, second discharge holes 23, third discharge holes 33 and fourth discharge holes 42 are the same; the number of first exhaust holes 14, second exhaust holes 24, third exhaust holes 34 and fourth exhaust holes 43 are the same; the number of first air inlets 15, second air inlets 25, third air inlets 35 and fourth air inlets 44 are the same; and the number of first exhaust holes 16, second exhaust holes 26, third exhaust holes 36 and fourth exhaust holes 45 are the same.

[0053] Reference Figure 3The air distribution plate 1 has a rectangular first groove 17 on the side facing away from the fuel preheating plate 2. Multiple first ribs 18 are evenly spaced parallel to each other along the length of the first groove 17. Multiple air distribution channels 11 are formed between two connected first ribs 18 and between the first ribs 18 and the walls of the adjacent first groove 17 along their length. Gaps are left between the two ends of each first rib 18 and the two walls of the first groove 17 along its width, allowing the first ends and second ends of the multiple air distribution channels 11 to communicate with each other. Each first air inlet 15 is connected to the first groove 17 via a first air inlet connection channel 151, and each first air outlet 16 is connected to the first groove 17 via a first air outlet connection channel 161, so that both the first air inlet 15 and the first air outlet 16 are connected to the air distribution channels 11. The first feed hole 12, the first discharge hole 13, and the first exhaust hole 14 are not connected to the first groove 17.

[0054] Reference Figure 4 The fuel preheating plate 2 has a rectangular second groove 27 on the side facing away from the fuel distribution plate 3. Multiple second ribs 28 are evenly spaced parallel to each other along the width direction within the second groove 27. Multiple preheating channels 21 are formed between two connected second ribs 28 and between the second ribs 28 and the wall of the adjacent second groove 27 along its width direction. The first end of each second rib 28 is connected to the first end wall of the second groove 27 along its length direction, and a gap is left between the second end of each second rib 28 and the second end wall of the second groove 27 along its length direction, so that the second ends of the multiple preheating channels 21 are interconnected. Each second feed hole 22 is connected to the second groove 27 through a first feed connection channel 221, so that the second feed hole 22 is connected to the inlet preheating channel 211. Each second discharge hole 23 is connected to the second groove 27 through a first discharge connection channel 231, so that the second discharge hole 23 is connected to the outlet preheating channel 212. The second air inlet 25, the second air outlet 26, the second exhaust outlet 24, and the second groove 27 are not connected.

[0055] Reference Figure 5The fuel distribution plate 3 has a rectangular third groove 37 on the side facing away from the fuel preheating plate 2. Multiple third ribs 38 are evenly spaced parallel to each other along the width direction within the third groove 37. The aforementioned fuel distribution channels 31 are formed between adjacent third ribs 38 and between the third ribs 38 and the width-direction groove walls of adjacent third grooves 37. Gaps are left between the two ends of each third rib 38 and the two end groove walls of the third groove 37 along its length direction, allowing the first ends and second ends of the multiple fuel distribution channels 31 to communicate with each other. Each third discharge hole 33 is connected to the third groove 37 via a second discharge connection channel 331, thus connecting the third discharge hole 33 to the fuel distribution channels 31. Each third exhaust hole 34 is connected to the third groove 37 via a first exhaust connection channel 341, thus connecting the third exhaust hole 34 to the fuel distribution channels 31. The third feed hole 32, the third air inlet 35, and the third exhaust hole 36 are not connected to the third groove 37.

[0056] Optionally, during processing, the air distribution channel 11, preheating channel 21, and fuel distribution channel 31 can be manufactured by machining or etching. When machining, grooves are machined into each plate, ribs are formed by sheet metal stamping, and then the ribs are welded into the corresponding grooves. When etching, the channels are formed directly on each plate. Generally, the bottom of the air distribution plate 1 is made of a thin plate, meaning the bottom thickness of the air distribution plate 1 (i.e., the thickness between the bottom surface of the first groove 17 and the outer surface of the bottom of the air distribution plate 1) is relatively thin, for example, 0.2-0.5 mm. This enhances heat conduction and improves the preheating effect on cold fuel.

[0057] Further optional, to ensure the fuel cell stack is sealed, refer to Figure 2 The air distribution plate 1, fuel preheating plate 2, and fuel distribution plate 3 are welded together to form an integrated connecting plate. The preheating channel 21 is spatially located between the air distribution channel 11 and the fuel distribution channel 31. After processing, the channels of the air distribution plate 1, fuel preheating plate 2, and fuel distribution plate 3 can be joined together by means of brazing or diffusion welding to form an integrated connecting plate, ensuring the sealing and fixation between the three plates.

[0058] In practical applications, the fuel preheating plate 2 and the fuel distribution plate 3 can be two separate plates, with the preheating channel 21 and the fuel distribution channel 31 processed separately and then welded together, depending on the needs.

[0059] Alternatively, the fuel preheating plate 2 and the fuel distribution plate 3 are the upper and lower parts of the same plate, with the preheating channel 21 and the fuel distribution channel 31 located on opposite sides of the plate. In this case, each of the second feed holes 22 and the third feed holes 32, the second discharge holes 23 and the third discharge holes 33, the second exhaust holes 24 and the third exhaust holes 34, the second air inlet holes 25 and the third air inlet holes 35, and the second air outlet holes 26 and the third air outlet holes 36 respectively constitute the upper and lower parts of the same through hole.

[0060] To further ensure the sealing of the fuel cell stack, refer to Figure 7 A first sealing gasket ring 5 is provided between the fuel distribution plate 3 and the single battery plate 4. The first sealing gasket ring 5 is provided with multiple fifth feed holes 51, multiple fifth discharge holes 52, multiple fifth exhaust holes 53, multiple fifth exhaust holes 54 and multiple fifth exhaust holes 55 respectively facing and communicating with multiple third feed holes 32, multiple third discharge holes 33, multiple third exhaust holes 34, multiple third air inlets 35 and multiple third exhaust holes 36.

[0061] Reference Figure 8 On the side of the air distribution plate 1 facing away from the fuel preheating plate 2, a second sealing gasket ring 6 is also provided. The second sealing gasket ring 6 is provided with a plurality of sixth feed holes 61, a plurality of sixth discharge holes 62, a plurality of sixth exhaust holes 63, a plurality of sixth exhaust holes 64 and a plurality of sixth exhaust holes 65 respectively facing and communicating with a plurality of second feed holes 22, a plurality of second discharge holes 23, a plurality of second exhaust holes 24, a plurality of second air inlets 25 and a plurality of second exhaust holes 26.

[0062] It should be noted that the fuel cell stack unit in this application is mainly used as the connecting plate of a solid oxide fuel cell (SOFC). Solid oxide fuel cells differ significantly from other existing battery types, such as proton exchange membrane fuel cells (PEMFC), in terms of material system, working principle, operating temperature, and heat exchange capacity. The electrolyte layer of a PEMFC is an organic ionomer membrane that conducts protons, and the connecting plate is typically made of graphite or titanium alloy. The operating temperature of a PEMFC is limited by the material system, approximately 70℃-80℃. The electrolyte in a SOFC is a ceramic material that conducts oxygen ions, and the connecting plate is typically made of stainless steel or Fe-Cr alloy. The electrolyte layer of a SOFC can only conduct oxygen ions at high temperatures, with an operating temperature of approximately 600℃-800℃. This application increases the gas temperature from 400℃-500℃ to 650℃-750℃, with a temperature difference of approximately 200℃-300℃ before and after heat exchange, resulting in greater heat exchange capacity and better heat exchange performance.

[0063] Furthermore, this application also provides a solid oxide fuel cell, comprising multiple sets of the above-described stack units 100 stacked sequentially. It has the same effects as the aforementioned stack units 100.

[0064] Furthermore, to facilitate the introduction of hydrogen fuel, the intake and exhaust of air, and the discharge of exhaust gas, the solid oxide fuel cell also includes a top plate, a bottom plate, a feed manifold, an exhaust manifold, an intake manifold, and an exhaust manifold. Multiple stack units 100 are sandwiched between the top plate and the bottom plate. The feed manifold, exhaust manifold, intake manifold, and exhaust manifold are connected to one of the top plate and the bottom plate. The feed manifold can be connected to multiple cold fuel inlets 101, the exhaust manifold can be connected to multiple exhaust outlets 103, the intake manifold can be connected to multiple air inlets 104, and the exhaust manifold can be connected to multiple air outlets 105.

[0065] To further ensure a tight seal, refer to... Figure 9 A third sealing gasket ring 7 is also provided between the base plate and the single battery panel 4 in the stack unit 100 near the base plate.

[0066] Furthermore, the third sealing ring 7 is provided with a plurality of seventh feed holes 71, a plurality of seventh discharge holes 72, a plurality of seventh exhaust holes 73, a plurality of seventh exhaust holes 74 and a plurality of seventh exhaust holes 75 respectively facing and communicating with a plurality of fourth feed holes 41, a plurality of fourth discharge holes 42, a plurality of fourth exhaust holes 43, a plurality of fourth air inlets 44 and a plurality of fourth exhaust holes 45.

[0067] Reference Figures 7 to 9 The first sealing ring 5, the second sealing ring 6, and the third sealing ring 7 are all rectangular annular structures with uniformly spaced rectangular through holes in the inner ring. The number of the fifth feed hole 51, the sixth feed hole 61, and the seventh feed hole 71 is the same as the number of the first feed hole 12, and each of these holes forms part of the cold fuel inlet 101. The number of the fifth discharge hole 52, the sixth discharge hole 62, and the seventh discharge hole 72 is the same as the number of the second discharge hole 23, and each of these holes forms part of the preheated fuel outlet 102.

[0068] It is understood that the multiple first discharge holes 13 in the air distribution plate 1 of the fuel cell stack unit 100 near the top plate, and the multiple sixth discharge holes 62 in the second sealing gasket ring 6 on the air distribution plate 1, will be blocked by the bottom surface of the top plate and will not communicate with the cold fuel inlet 101. The number of the fifth exhaust port 53, the sixth exhaust port 63, and the seventh exhaust port 73 is the same as the number of the first exhaust port 14, and the fifth exhaust port 53, the sixth exhaust port 63, and the seventh exhaust port 73 all constitute part of the exhaust outlet 103. The number of the fifth air inlet port 54, the sixth air inlet port 64, and the seventh air inlet port 74 is the same as the number of the first air inlet port 15, and the fifth air inlet port 54, the sixth air inlet port 64, and the seventh air inlet port 74 all constitute part of the air inlet 104. The number of the fifth exhaust port 55, the sixth exhaust port 65, and the seventh exhaust port 75 is the same, and the fifth exhaust port 55, the sixth exhaust port 65, and the seventh exhaust port 75 all constitute part of the air outlet 105.

[0069] Each fifth discharge port 52 can be connected to the inner rectangular through hole of the first sealing ring 5 through the third discharge connection channel 521, and each fifth exhaust port 53 can be connected to the inner rectangular through hole of the first sealing ring 5 through the second exhaust connection channel 531; the fifth feed port 51, the fifth air inlet port 54, and the fifth exhaust port 55 are not connected to the inner rectangular through hole of the first sealing ring 5. Each sixth air inlet port 64 can be connected to the inner rectangular through hole of the second sealing ring 6 through the second air inlet connection channel 641, and each sixth exhaust port 65 can be connected to the inner rectangular through hole of the second sealing ring 6 through the second exhaust connection channel 651; the sixth feed port 61, the sixth discharge port 62, and the sixth exhaust port 63 are not connected to the inner rectangular through hole of the second sealing ring 6. The seventh feed port 71, the seventh discharge port 72, the seventh exhaust port 73, the seventh air inlet port 74, and the seventh exhaust port 75 are not connected to the inner rectangular through hole of the third sealing ring 7.

[0070] Whether the feed manifold, exhaust manifold, intake manifold, and exhaust manifold are connected to the top plate or the bottom plate can be determined according to actual needs. For example, in a specific example, both the feed manifold and intake manifold are connected to the top plate, while both the exhaust manifold and exhaust manifold are connected to the bottom plate. The top plate has a feed chamber that communicates with the feed manifold and an intake chamber that communicates with the intake manifold. On the side of the top plate facing the fuel cell unit 100, there are multiple feed connection holes communicating with the feed chamber and multiple intake connection holes communicating with the intake chamber. The number of multiple feed connection holes is the same as the number of the first feed holes 12 on the air distribution plate 1, and they are vertically aligned and connected. The number of multiple intake connection holes is the same as the number of the first intake holes 15 on the air distribution plate 1, and they are vertically aligned and connected. An exhaust gas chamber that can communicate with the exhaust manifold and an exhaust gas chamber that can communicate with the intake manifold are provided inside the base plate. On the side of the base plate facing the fuel cell unit 100, a plurality of exhaust gas connection holes that communicate with the exhaust gas chamber and a plurality of exhaust gas connection holes that communicate with the exhaust gas chamber are provided. The number of the plurality of exhaust gas connection holes is the same as the number of the fourth exhaust gas holes 43 on the single battery panel 4, and they are directly connected vertically. The number of exhaust gas connection holes is the same as the number of the fourth exhaust gas holes 45 on the single battery panel 4, and they are directly connected vertically.

[0071] After multiple sets of fuel cell stack units 100 are stacked vertically, the cold fuel inlet 101, preheated fuel outlet 102, exhaust gas outlet 103, air inlet 104, and exhaust outlet in each set of fuel cell stack units 100 are all arranged vertically and vertically in direct connection. Furthermore, a first sealing gasket ring 5 is provided between the fuel distribution plate 3 and the single battery plate 4 of each set of fuel cell stack units 100, a second sealing gasket ring 6 is provided between the air distribution plate 1 and the single battery plate 4 of two adjacent fuel cell stack units 100, a second sealing gasket ring 6 is provided between the air distribution plate 1 and the top plate of the fuel cell stack unit 100 near the top plate, and a third sealing gasket ring 7 is provided between the single battery plate 4 and the bottom plate of the fuel cell stack unit 100 near the bottom plate.

[0072] During operation, air enters the air inlet 104 of each fuel cell stack unit 100 through the intake manifold, intake chamber, and multiple intake connection holes. After entering the multiple air distribution channels 11 of the air distribution plate 1, it enters the exhaust chamber through multiple air outlets 105 and is discharged through the exhaust manifold. During this process, the air is heated by the large Joule heat release inside the fuel cell stack and becomes hot air. Hydrogen fuel enters the cold fuel inlet 101 of each fuel cell stack unit 100 through the feed manifold, feed chamber, and multiple feed connection holes. The cold fuel enters the inlet preheating channel 211 of each fuel cell stack unit 100 through the cold fuel inlet 101 of each fuel cell stack unit 100. The preheated fuel enters the fuel distribution channel 31 through the outlet preheating channel 212 and the preheated fuel outlet 102. After being distributed by multiple fuel distribution channels 31, it is evenly distributed on the anode surface of the single cell plate 4 and generates electricity. The exhaust gas and unreacted hydrogen fuel enter the exhaust gas chamber through multiple exhaust gas outlets 103 and are then discharged from the fuel cell stack through the exhaust gas manifold.

[0073] The clever perforation design on each plate enables effective gas flow. The air distribution plate 1, fuel preheating plate 2, and fuel distribution plate 3 are welded into an integrated connecting plate. The perforations on the sealing gaskets correspond perfectly with the corresponding holes on each plate, which effectively ensures the sealing of the fuel cell stack, reduces the thermal cycle stress of the stack, effectively prevents interference between air and hydrogen fuel, and also effectively prevents the mixing of cold fuel and preheated fuel, thus achieving complete sealing of fuel and air.

[0074] Alternatively, the first sealing ring 5, the second sealing ring 6, and the third sealing ring 7 can be made of mica or glass ceramic. When each sealing ring is made of a compression sealing material such as mica, after stacking the top plate, each fuel cell unit 100, and the bottom plate, the entire assembly needs to be compressed and fixed using bolts or other fasteners. When each sealing ring is made of a fully sealing material such as glass ceramic, after stacking the top plate, each fuel cell unit 100, and the bottom plate, the sealing rings need to be glued to the adjacent layers.

[0075] The above are merely illustrative embodiments of the present invention and are not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A fuel cell stack unit for use in a solid oxide fuel cell, characterized in that, Each fuel cell stack unit includes an air distribution plate, a fuel preheating plate, a fuel distribution plate, and a single cell plate arranged in a stacked sequence. Multiple cold fuel inlets and multiple preheated fuel outlets are provided at the first end of the fuel cell stack unit, and multiple exhaust gas outlets are provided at the second end of the fuel cell stack unit. Multiple preheating channels and multiple fuel distribution channels are respectively formed on the back-to-back surfaces of the fuel preheating plate and the fuel distribution plate; a portion of the preheating channels are connected to the corresponding cold fuel inlet, and the remaining portion of the preheating channels are connected to the first end of the multiple fuel distribution channels through the corresponding preheated fuel outlet, and the second end of the multiple fuel distribution channels is connected to the multiple exhaust gas outlets.

2. The fuel cell stack unit as described in claim 1, characterized in that, The plurality of preheating channels include a plurality of inlet preheating channels and a plurality of outlet preheating channels arranged in parallel and staggered manner. The first ends of the plurality of inlet preheating channels are respectively connected to the plurality of cold fuel inlets, the first ends of the plurality of outlet preheating channels are respectively connected to the plurality of preheated fuel outlets, and the second ends of the plurality of inlet preheating channels are interconnected with the second ends of the plurality of outlet preheating channels.

3. The fuel cell stack unit as described in claim 2, characterized in that, The quantity of cold fuel inlet is greater than the quantity of preheated fuel outlet.

4. The fuel cell stack unit as described in claim 2, characterized in that, The number of cold fuel inlets is three, and the number of preheated fuel outlets is two.

5. The fuel cell stack unit as claimed in claim 1, characterized in that, The air distribution plate has multiple air distribution channels, and each group of fuel cell stack units also includes multiple air inlets and multiple air outlets. The two ends of the multiple air distribution channels are respectively connected to the multiple air inlets and the multiple air outlets.

6. The fuel cell stack unit as described in claim 5, characterized in that, Both the preheating channel and the air distribution channel are straight channels, and the length direction of the air distribution channel is perpendicular to the length direction of the preheating channel.

7. The fuel cell stack unit as claimed in claim 5, characterized in that, The air distribution plate has multiple first inlet holes and multiple first outlet holes at its first end, and multiple first exhaust holes at its second end; the fuel preheating plate has multiple second inlet holes and multiple second outlet holes at its first end, and multiple second exhaust holes at its second end; the fuel distribution plate has multiple third inlet holes and multiple third outlet holes at its first end, and multiple third exhaust holes at its second end; the single battery panel has multiple fourth inlet holes and multiple fourth outlet holes at its first end, and multiple fourth exhaust holes at its second end. Multiple first feed holes, multiple second feed holes, multiple third feed holes, and multiple fourth feed holes are arranged vertically opposite each other to form multiple cold fuel inlets. Multiple first discharge holes, multiple second discharge holes, multiple third discharge holes, and multiple fourth discharge holes are arranged vertically opposite each other to form multiple preheated fuel outlets. Multiple first exhaust gas holes, multiple second exhaust gas holes, multiple third exhaust gas holes, and multiple fourth exhaust gas holes are arranged vertically opposite each other to form multiple exhaust gas outlets.

8. The fuel cell stack unit as claimed in claim 7, characterized in that, Multiple first air inlets and multiple first air outlets are respectively opened on both sides of the air distribution plate; multiple second air inlets and multiple second air outlets are respectively opened on both sides of the fuel preheating plate; multiple third air inlets and multiple third air outlets are respectively opened on both sides of the fuel distribution plate; and multiple fourth air inlets and multiple fourth air outlets are opened on the single battery plate. Multiple first air inlets, multiple second air inlets, multiple third air inlets, and multiple fourth air inlets are arranged vertically opposite each other to form multiple air inlets, and multiple first air outlets, multiple second air outlets, multiple third air outlets, and multiple fourth air outlets are arranged vertically opposite each other to form multiple air outlets.

9. The fuel cell stack unit as claimed in claim 8, characterized in that, The air distribution plate, the fuel preheating plate, and the fuel distribution plate are welded together to form an integrated connecting plate.

10. The fuel cell stack unit as claimed in claim 1 or 9, characterized in that, The fuel preheating plate and the fuel distribution plate are the upper and lower parts of the same plate body, and the preheating channel and the fuel distribution channel are opened on opposite side plates of the plate body.

11. The fuel cell stack unit as claimed in claim 9, characterized in that, A first sealing gasket ring is provided between the fuel distribution plate and the single battery plate. The first sealing gasket ring has multiple fifth feed holes, multiple fifth discharge holes, multiple fifth exhaust holes, multiple third exhaust holes, multiple third air inlets and multiple third exhaust holes respectively facing and communicating with multiple third feed holes, multiple third discharge holes, multiple third exhaust holes, multiple fifth air inlets and multiple third exhaust holes.

12. The fuel cell stack unit as claimed in claim 11, characterized in that, A second sealing gasket ring is also provided on the side of the air distribution plate opposite to the fuel preheating plate. The second sealing gasket ring is provided with a plurality of sixth feed holes, a plurality of sixth discharge holes, a plurality of sixth exhaust holes, a plurality of second air inlets and a plurality of second air outlets respectively facing and communicating with a plurality of second feed holes, a plurality of second discharge holes, a plurality of second exhaust holes, a plurality of second air inlets and a plurality of second air outlets.

13. The fuel cell stack unit as claimed in claim 1, characterized in that, The cold fuel inlet is used to introduce hydrogen fuel at a temperature of 400℃-500℃.

14. A solid oxide fuel cell, characterized in that, It includes multiple sets of stacked cells as described in any one of claims 1-13.

15. The solid oxide fuel cell as claimed in claim 14, characterized in that, The solid oxide fuel cell also includes a top plate, a bottom plate, a feed manifold, a tail gas manifold, an intake manifold, and an outlet manifold, with multiple stack units sandwiched between the top plate and the bottom plate; The feed manifold, the exhaust manifold, the intake manifold, and the outlet manifold are connected to one of the top plate and the bottom plate. The feed manifold can be connected to multiple cold fuel inlets, the exhaust manifold can be connected to multiple exhaust outlets, the intake manifold can be connected to multiple air inlets, and the outlet manifold can be connected to multiple air outlets.

16. The solid oxide fuel cell as claimed in claim 15, characterized in that, A third sealing gasket ring is also provided between the base plate and the single battery panel in the stack unit near the base plate.

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