Fuel cell system

Abstract

The utility model belongs to the technical field of fuel cells, and discloses a fuel cell system, which comprises a first fuel cell, a fuel source, a reformer, a gas source, a preheater and a mixing flow channel, a first flow channel is communicated between the fuel source and an anode inlet of the first fuel cell, a reforming cavity of the reformer is communicated on the first flow channel, and a second flow channel is communicated between the gas source and an anode inlet of the gas source. A second flow channel is communicated between the gas source and the cathode inlet of the first fuel cell, the preheater is provided with a preheating cavity, the preheating cavity is communicated with the second flow channel, and the mixing flow channel is used for conveying cathode exhaust gas of the first fuel cell to the second flow channel. According to the fuel cell system, hot air discharged from the fuel cell is mixed with air at the inlet or the outlet of the preheater, so that the working pressure of the preheater is relieved, and the working reliability and stability of the fuel cell system are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, in particular to a fuel cell system. Background Art

[0002] In order to ensure working performance, current fuel cells generally have temperature requirements for the air entering the fuel cell.

[0003] In the prior art, an air preheater is generally added to heat the cold air at the cathode air inlet of the fuel cell to the inlet temperature required by the stack. However, it is currently necessary to increase the air inlet temperature of the fuel cell as much as possible within the temperature boundary range, so the heat exchange efficiency of the air preheater is required to be high, and the workload of the air preheater is increased, resulting in a high heat exchange pressure of the air preheater. Long-term high-load operation will also increase the risk of damage to the air preheater, affecting the reliability and stability of the entire fuel cell system. Utility Model Content

[0004] The purpose of the utility model is to provide a fuel cell system, which mixes the hot air exhausted from the fuel cell with the air at the inlet or outlet of the preheater, effectively increases the air temperature at the preheater outlet, relieves the working pressure of the preheater, reduces the risk of damage to the preheater, and improves the reliability and stability of the fuel cell system.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] A fuel cell system comprises a first fuel cell, a fuel source, a reformer, a gas source, a preheater and a mixing channel; wherein:

[0007] A first flow channel is connected between the fuel source and the anode inlet of the first fuel cell, and the reformer has a reforming chamber, which is connected to the first flow channel; a second flow channel is connected between the gas source and the cathode inlet of the first fuel cell, and the preheater has a preheating chamber, which is connected to the second flow channel, and the mixing flow channel is used to transport the cathode exhaust of the first fuel cell to the second flow channel.

[0008] Preferably, the reformer has a first heat exchange chamber, and the first heat exchange chamber is connected to the mixing flow channel;

[0009] The fuel in the reforming chamber can exchange heat with the gas in the mixing channel through the first heat exchange chamber.

[0010] Preferably, it further comprises a burner, the preheater has a second heat exchange chamber, the anode outlet and the cathode outlet of the first fuel cell are respectively connected to the inlet of the burner, the outlet of the burner is connected to the tail exhaust pipe, and the second heat exchange chamber is connected to the tail exhaust pipe;

[0011] The gas in the preheating chamber can exchange heat with the exhaust gas in the tail exhaust pipe through the second heat exchange chamber.

[0012] Preferably, an ejector is connected between the mixing flow channel and the outlet of the preheating chamber, and the ejector is used to eject the exhaust gas from the outlet of the first fuel cell into the mixing flow channel.

[0013] Preferably, the second end of the mixing channel is connected to the second channel between the gas source and the preheating chamber.

[0014] Preferably, a third flow channel is further included, and the gas source is also connected to the cathode inlet of the first fuel cell through the third flow channel.

[0015] Preferably, a second mixer is further included, and the second mixer is used to mix the gas in the second flow channel and the gas in the third flow channel, and pass the mixed gas into the cathode inlet of the first fuel cell.

[0016] Preferably, a second fuel cell is also included, wherein the anode outlet of the first fuel cell, the anode inlet of the second fuel cell, and the anode outlet of the second fuel cell are connected in sequence, and the cathode outlet of the first fuel cell, the cathode inlet of the second fuel cell, and the cathode outlet of the second fuel cell are connected in sequence.

[0017] Preferably, a fourth flow channel is further included, and the gas source is connected to the cathode inlet of the second fuel cell through the fourth flow channel.

[0018] Preferably, a first mixer is further included, and the first mixer is used to mix the gas in the mixing channel and the gas in the second channel, and pass the mixed gas into the cathode inlet of the first fuel cell.

[0019] Beneficial effects:

[0020] The fuel cell system provided by the utility model comprises a fuel source providing fuel that enters the anode inlet of the first fuel cell after undergoing a reforming reaction in a reformer on a first flow channel, a gas source providing air that enters the cathode inlet of the first fuel cell after being preheated in a preheater on a second flow channel, and after the reaction in the first fuel cell is completed, part of the hot air discharged from the cathode outlet of the first fuel cell can return to the second flow channel again through the mixing flow channel, and can be mixed with the air at the inlet or outlet of the preheater, thereby effectively increasing the outlet air temperature of the preheater, relieving the working pressure of the preheater, reducing the risk of damage to the preheater, and improving the reliability and stability of the operation of the fuel cell system.

[0021] In addition, hot air mixing can increase the air flow through the fuel cell stack, reduce the temperature distribution gradient of the battery cells inside the fuel cell, increase the load of the electrochemical reaction per unit area inside the electrode, and further increase the life of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a fuel cell system provided by an embodiment of the utility model;

[0023] Figure 2 This utility model is Figure 1 A local enlarged schematic diagram of the middle A;

[0024] Figure 3 is a structural schematic diagram of a fuel cell system provided by another embodiment of the utility model;

[0025] Figure 4 This utility model is Figure 3 A partial enlarged schematic diagram of point B in the middle;

[0026] Figure 5 This utility model is Figure 3 A partial enlarged schematic diagram of point C in the middle;

[0027] Figure 6 This utility model is Figure 3 A partial enlarged schematic diagram of point D in the middle;

[0028] Figure 7 This utility model is Figure 3 A partial enlarged schematic diagram of point E in the middle.

[0029] In the figure:

[0030] 11. a first fuel cell; 12. a second fuel cell;

[0031] 2. Fuel source;

[0032] 3. Reformer;

[0033] 4. Gas source;

[0034] 5. Preheater;

[0035] 6. Burner;

[0036] 71, mixing channel; 711, ejector; 72, first channel; 73, second channel; 74, third channel; 75, fourth channel;

[0037] 81. First mixer; 811. First inlet; 812. Second inlet; 813. First outlet; 82. Second mixer; 821. Third inlet; 822. Fourth inlet; 823. Second outlet; 83. Third mixer; 831. Fifth inlet; 832. Sixth inlet; 833. Third outlet; 84. Diverter; 841. Diverter inlet; 842. First diverter outlet; 843. Second diverter outlet; 844. Third diverter outlet. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0039] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0041] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0042] This embodiment provides a fuel cell system. Figure 1 to Figure 2 As shown, the fuel cell system includes a first fuel cell 11, a fuel source 2, a reformer 3, a gas source 4, a preheater 5 and a mixing channel 71.

[0043] A first flow channel 72 is connected between the fuel source 2 and the anode inlet of the first fuel cell 11, and the reformer 3 has a reforming chamber, which is connected to the first flow channel 72; a second flow channel 73 is connected between the gas source 4 and the cathode inlet of the first fuel cell 11, and the preheater 5 has a preheating chamber, which is connected to the second flow channel 73, and the mixing flow channel 71 is used to transport the cathode exhaust of the first fuel cell 11 to the second flow channel 73.

[0044] Specifically, a first end of the mixing channel 71 is connected to the cathode outlet of the first fuel cell 11 , and a second end of the mixing channel 71 is connected to the second channel 73 .

[0045] In this embodiment, the fuel source 2 provides fuel on the first flow channel 72, which enters the anode inlet of the first fuel cell 11 after being reformed by the reformer 3. The gas source 4 provides air on the second flow channel 73, which is preheated by the preheater 5 and then passed to the cathode inlet of the first fuel cell 11. After the reaction in the first fuel cell 11 is completed, part of the hot air discharged from the cathode outlet of the first fuel cell 11 can return to the second flow channel 73 through the mixing flow channel 71, and can be mixed with the air at the inlet or outlet of the preheater 5. This can effectively increase the outlet air temperature of the preheater 5, relieve the working pressure of the preheater 5, reduce the risk of damage to the preheater 5, and improve the reliability and stability of the fuel cell system.

[0046] In addition, hot air mixing can increase the air flow through the fuel cell stack, reduce the temperature distribution gradient of the battery cells inside the fuel cell, increase the load of the electrochemical reaction per unit area inside the electrode, and further increase the life of the fuel cell.

[0047] As an optional implementation, refer to Figure 1 In this embodiment, a portion of the hot air discharged from the cathode outlet of the first fuel cell 11 returns to the second flow channel 73 through the mixing flow channel 71 and is mixed with the air preheated at the outlet of the heat exchanger, effectively increasing the air temperature at the outlet of the heat exchanger.

[0048] Specifically, Figure 1 The dashed line indicates the mixing channel 71 , the dashed line indicates the first channel 72 , and the dashed line indicates the second channel 73 .

[0049] In this embodiment, the reformer 3 has a first heat exchange chamber, which is connected to the mixing flow channel 71. The fuel in the reforming chamber can exchange heat with the gas in the mixing flow channel 71 through the first heat exchange chamber. Specifically, the mixing flow channel 71 is connected to the first heat exchange chamber of the reformer 3, and the hot air in the mixing flow channel 71 will flow through the first heat exchange chamber and provide a certain amount of heat for the fuel in the reformer 3. The hot air enters the first heat exchange chamber and exchanges heat with the fuel in the reformer 3, ensuring that the reforming reaction of the fuel inside the reformer 3 is carried out normally and reliably.

[0050] In this embodiment, the fuel cell system further includes a burner 6, and the preheater 5 has a second heat exchange chamber.

[0051] The anode outlet and cathode outlet of the first fuel cell 11 are respectively connected to the inlet of the burner 6, the outlet of the burner 6 is connected to the tail exhaust pipe, and the second heat exchange chamber is connected to the tail exhaust pipe. The gas in the preheating chamber can exchange heat with the tail gas in the tail exhaust pipe through the second heat exchange chamber. Specifically, after the reaction in the first fuel cell 11 is completed, the cathode outlet of the first fuel cell 11 discharges hot air, and a part of the hot air is passed into the burner 6 for combustion, and the high-temperature exhaust gas generated after combustion will be discharged through the tail exhaust pipe. In the process of high-temperature gas flowing through the tail exhaust pipe, it will pass through the second heat exchange chamber, and can also provide a certain amount of heat for the heat exchanger. The second heat exchange chamber can exchange the heat of the high-temperature gas in the tail exhaust pipe with the air in the preheating chamber, further ensuring the heat exchange efficiency.

[0052] In this embodiment, an ejector 711 is connected between the mixing flow channel 71 and the outlet of the preheating chamber, and the ejector 711 is used to eject the exhaust gas at the outlet of the first fuel cell 11 into the mixing flow channel 71. Specifically, the ejector 711 includes a first air inlet, a second air inlet and an exhaust port. The first air inlet of the ejector 711 is connected to the preheating chamber, and the ejector 711 is connected to the mixing flow channel 71 through the second air inlet and the exhaust port. Specifically, when the ejector 711 is working, part of the air discharged from the preheating chamber can flow through the second air inlet and the exhaust port of the ejector 711 at a high speed into the mixing flow channel 71, and a negative pressure can be formed on one side of the first air inlet during the process, so that the air discharged at the cathode outlet of the first fuel cell 11 can more reliably and effectively pass through the first air inlet and enter the mixing flow channel 71, ensuring that the hot air at the cathode outlet of the first fuel cell 11 effectively flows in a directional manner in the mixing flow channel 71.

[0053] Specifically, it also includes a first mixer 81 , which is used to mix the gas in the blending channel 71 and the gas in the second channel 73 , and pass the mixed gas into the cathode inlet of the first fuel cell 11 .

[0054] Specifically, refer to Figures 1 to 4 As shown, the first mixer 81 has a first inlet 811, a second inlet 812 and a first outlet 813 which are connected to each other. Figure 1 to Figure 2 As shown, corresponding to Figure 1 In the fuel cell system, the first mixer 81 is connected to the second flow channel 73 between the preheating chamber and the cathode inlet of the first fuel cell 11 through the first inlet 811 and the first outlet 813, and is connected to the second end of the mixing flow channel 71 through the second inlet 812. Specifically, by providing the first mixer 81, the hot air in the mixing flow channel 71 can be reliably and evenly mixed with the hot air at the outlet of the preheater 5, and the hot air after mixing is discharged from the first outlet 813 and passed into the cathode inlet of the first fuel cell 11.

[0055] As an optional implementation, refer to Figures 3 to 7 As shown, in this embodiment, the second end of the mixing channel 71 is connected to the second channel 73 between the air source 4 and the preheating chamber. In this way, the hot air in the mixing channel 71 can be directly introduced into the inlet of the preheater 5.

[0056] exist Figure 3 In the figure, the thin dotted line indicates the mixing channel 71, the single-dot chain line indicates the first channel 72, and the double-dot chain line indicates the second channel 73.

[0057] Specific reference Figure 3 to Figure 4 As shown, corresponding to Figure 3 In the fuel cell system, the first mixer 81 is connected to the second flow channel 73 between the gas source 4 and the preheating chamber through the first inlet 811 and the first outlet 813, and is connected to the second end of the mixing flow channel 71 through the second inlet 812. In this way, the hot air in the mixing flow channel 71 can be reliably and evenly mixed with the hot air provided by the gas source 4, and the air after mixing is discharged from the first outlet 813 and passed to the inlet of the preheater 5.

[0058] Furthermore, a third flow channel 74 is included, and the gas source 4 is also connected to the cathode inlet of the first fuel cell 11 through the third flow channel 74. Specifically in this embodiment, the first end of the third flow channel 74 is connected to the second flow channel 73 between the gas source 4 and the mixing flow channel 71, and the second end of the third flow channel 74 is connected to the second flow channel 73 between the preheating chamber and the cathode inlet of the first fuel cell 11. Specifically, Figure 3The thick solid line indicates the third flow channel 74. By setting the third flow channel 74, part of the air provided by the air source 4 can be directly mixed with the hot air on the outlet side of the preheater 5 on the second flow channel 73, so that the temperature of the air before entering the first fuel cell 11 can be adjusted to avoid the air temperature at the cathode inlet of the first fuel cell 11 being too high.

[0059] Furthermore, the fuel cell system also includes a second fuel cell 12, the anode outlet of the first fuel cell 11, the anode inlet of the second fuel cell 12, and the anode outlet of the second fuel cell 12 are connected in sequence, and the cathode outlet of the first fuel cell 11, the cathode inlet of the second fuel cell 12, and the cathode outlet of the second fuel cell 12 are connected in sequence.

[0060] In this embodiment, the anode outlet and the cathode outlet of the second fuel cell 12 are respectively connected to the inlet of the burner 6. In this way, the fuel cell system can be optionally configured as a two-stage fuel cell system.

[0061] Furthermore, the above-mentioned two-stage fuel cell system further includes a fourth flow channel 75, through which the gas source 4 is connected to the cathode inlet of the second fuel cell 12. Specifically in this embodiment, the first end of the fourth flow channel 75 is connected to the second flow channel 73 between the gas source 4 and the mixing flow channel 71, and the second end of the fourth flow channel 75 is connected to the connecting flow channel between the cathode outlet of the first fuel cell 11 and the cathode inlet of the second fuel cell 12.

[0062] Specifically, Figure 3 The fourth flow channel 75 is indicated by the thick dotted line. By setting the fourth flow channel 75, part of the air provided by the gas source 4 can be directly mixed with the hot air on the outlet side of the preheater 5 on the second flow channel 73, so that the temperature of the air before entering the second fuel cell 12 can be adjusted to avoid the air temperature at the cathode inlet of the second fuel cell 12 being too high.

[0063] Specifically, refer to Figure 3 , Figure 5As shown, for the above-mentioned two-stage fuel cell system, a second mixer 82 is also included, and the second mixer 82 is used to mix the gases in the second flow channel 73 and the third flow channel 74, and pass the mixed gas to the cathode inlet of the first fuel cell 11. Specifically, the second mixer 82 has a third inlet 821, a fourth inlet 822 and a second outlet 823 that are connected and arranged. The second mixer 82 is connected to the second flow channel 73 between the outlet of the preheater 5 and the cathode inlet of the first fuel cell 11 through the third inlet 821 and the second outlet 823, and is connected to the second end of the third flow channel 74 through the fourth inlet 822. Specifically, by providing the second mixer 82, the hot air in the mixing flow channel 71 can be reliably and evenly mixed with the air in the third flow channel 74, and the air after mixing will be discharged from the second outlet 823 and passed to the cathode inlet of the first fuel cell 11.

[0064] Specifically, refer to Figure 3 , Figure 6 As shown, for the above-mentioned two-stage fuel cell system, a third mixer 83 is also included. The third mixer 83 has a fifth inlet 831, a sixth inlet 832 and a third outlet 833 which are connected and arranged. The third mixer 83 is connected to the flow channel between the cathode outlet of the first fuel cell 11 and the cathode inlet of the second fuel cell 12 through the fifth inlet 831 and the third outlet 833, and is connected to the second end of the fourth flow channel 75 through the sixth inlet 832. Specifically, by providing the third mixer 83, the hot air in the flow channel between the cathode outlet of the first fuel cell 11 and the cathode inlet of the second fuel cell 12 can be reliably and evenly mixed with the air in the fourth flow channel 75, and the air after mixing will be discharged from the third outlet 833 and passed to the cathode inlet of the second fuel cell 12.

[0065] Specifically, refer to Figure 3 , Figure 7 As shown, the above-mentioned secondary fuel cell system also includes a diverter 84, which includes a diverter inlet 841, a first diverter outlet 842, a second diverter outlet 843 and a third diverter outlet 844 that are interconnected. The diverter 84 is connected to the second flow channel 73 between the gas source 4 and the first mixer 81 through the diverter inlet 841 and the first diverter outlet 842, the diverter 84 is connected to the first end of the third flow channel 74 through the second diverter outlet 843, and the diverter 84 is connected to the first end of the fourth flow channel 75 through the third diverter outlet 844.

[0066] Optionally, the flow dividing member 84 may be configured as a four-way valve.

[0067] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A fuel cell system, characterized in that: It comprises a first fuel cell (11), a fuel source (2), a reformer (3), a gas source (4), a preheater (5) and a mixing channel (71); wherein: A first flow channel (72) is connected between the fuel source (2) and the anode inlet of the first fuel cell (11); the reformer (3) has a reforming chamber, and the reforming chamber is connected to the first flow channel (72); a second flow channel (73) is connected between the gas source (4) and the cathode inlet of the first fuel cell (11); the preheater (5) has a preheating chamber, and the preheating chamber is connected to the second flow channel (73); the mixing flow channel (71) is used to transport the cathode exhaust of the first fuel cell (11) to the second flow channel (73).

2. The fuel cell system according to claim 1, characterized in that: The reformer (3) has a first heat exchange chamber, and the first heat exchange chamber is connected to the mixing flow channel (71); The fuel in the reforming chamber can exchange heat with the gas in the mixing channel (71) through the first heat exchange chamber.

3. The fuel cell system according to claim 1, characterized in that: It also includes a burner (6), the preheater (5) has a second heat exchange chamber, the anode outlet and the cathode outlet of the first fuel cell (11) are respectively connected to the inlet of the burner (6), the outlet of the burner (6) is connected to the tail exhaust pipe, and the second heat exchange chamber is connected to the tail exhaust pipe; The gas in the preheating chamber can exchange heat with the exhaust gas in the tail exhaust pipe through the second heat exchange chamber.

4. The fuel cell system according to claim 1, characterized in that: An ejector (711) is connected between the mixing flow channel (71) and the outlet of the preheating chamber, and the ejector (711) is used to eject the exhaust gas from the outlet of the first fuel cell (11) into the mixing flow channel (71).

5. The fuel cell system according to claim 1, characterized in that: The second end of the mixing channel (71) is connected to the second channel (73) between the gas source (4) and the preheating chamber.

6. The fuel cell system according to claim 5, characterized in that: It also includes a third flow channel (74), and the gas source (4) is also connected to the cathode inlet of the first fuel cell (11) through the third flow channel (74).

7. The fuel cell system according to claim 6, characterized in that: It also includes a second mixer (82), which is used to mix the gas in the second flow channel (73) and the gas in the third flow channel (74), and pass the mixed gas to the cathode inlet of the first fuel cell (11).

8. The fuel cell system according to claim 1, characterized in that: It also includes a second fuel cell (12), wherein the anode outlet of the first fuel cell (11), the anode inlet of the second fuel cell (12), and the anode outlet of the second fuel cell (12) are connected in sequence, and the cathode outlet of the first fuel cell (11), the cathode inlet of the second fuel cell (12), and the cathode outlet of the second fuel cell (12) are connected in sequence.

9. The fuel cell system according to claim 8, characterized in that: It also includes a fourth flow channel (75), through which the gas source (4) is connected to the cathode inlet of the second fuel cell (12).

10. The fuel cell system according to claim 1, characterized in that: It also includes a first mixer (81), which is used to mix the gas in the mixing channel (71) and the gas in the second channel (73), and pass the mixed gas into the cathode inlet of the first fuel cell (11).

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