Air inlet system of small solid oxide fuel cell

Abstract

The utility model provides a small solid oxide fuel cell gas inlet system, which comprises an anode air system, an anode gas system and a cathode air system, the anode gas system comprises a gas pipeline and a mixing pipeline, the mixing pipeline is connected with the gas pipeline, a gas proportional valve and a gas flowmeter are arranged on the gas pipeline, and the cathode air system is connected with the anode gas system. An electromagnetic valve is arranged on the mixing pipeline, the anode air system comprises an anode air pipeline and an anode fan, the anode fan is connected to one end of the anode air pipeline, the other end of the anode air pipeline is connected with the mixing pipeline, an anode air flow meter is arranged on the anode air pipeline, and the cathode air system comprises a cathode air pipeline and a cathode fan. One end of the cathode air pipeline is connected with the cathode fan, the other end of the cathode air pipeline is used for being connected with a cathode of the electric pile, and a cathode air flow meter is arranged on the cathode air pipeline. According to the utility model, the flow and components of air entering the reformer and the electric pile can be accurately controlled.

Description

Technical Field

[0001] This utility model relates to the field of solid oxide fuel cell technology, and specifically to a small solid oxide fuel cell intake system. Background Technology

[0002] Solid oxide fuel cells operate under various conditions, including start-up, rated operation, standby, and purging. Solid oxide fuel cells have high requirements for the composition of the gas entering the stack under different operating conditions. Different gas compositions are required under different operating conditions to ensure the normal operation of the battery. Therefore, it is necessary to design an intake system that can accurately control the composition of the gas entering the stack under different operating conditions. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a small solid oxide fuel cell air intake system that can precisely control the airflow and composition entering the reformer and fuel cell stack, reduce accessory power consumption, enhance air-fuel mixing, and improve the system efficiency of the fuel cell.

[0004] To address the aforementioned technical problems, this utility model provides a small solid oxide fuel cell air intake system, comprising an anode air system, an anode fuel gas system, and a cathode air system. The anode fuel gas system includes a fuel gas pipeline and a mixing pipeline. One end of the mixing pipeline is connected to the fuel gas pipeline, and the other end is connected to a reformer. A fuel gas proportional valve and a fuel gas flow meter are installed on the fuel gas pipeline, and a solenoid valve is installed on the mixing pipeline. The anode air system includes an anode air pipeline and an anode fan. The anode fan is connected to one end of the anode air pipeline, and the other end of the anode air pipeline is connected to the mixing pipeline. An anode air flow meter is installed on the anode air pipeline. The cathode air system includes a cathode air pipeline and a cathode fan. One end of the cathode air pipeline is connected to the cathode fan, and the other end is connected to the cathode of the fuel cell stack. A cathode air flow meter is installed on the cathode air pipeline.

[0005] In some embodiments, the anode gas system includes a mixer, a first end of which is connected to a mixing pipe, a second end of which is connected to a gas pipe, and a third end of which is connected to an anode air pipe.

[0006] In some embodiments, an impeller is provided at the third end of the mixer, and air in the anode air duct enters the mixing duct through the impeller.

[0007] In some embodiments, a gas flow channel is provided at the second end of the mixer, the diameter of which is smaller than the diameter of the gas pipeline.

[0008] In some embodiments, the impeller is arranged on the end face near the third end of the mixer, and the outlet of the gas flow path is arranged near the middle of the mixer.

[0009] In some embodiments, the included angle between the gas pipeline and the anode air pipeline is an acute angle.

[0010] In some embodiments, the included angle between the gas pipeline and the anode air pipeline is 30° to 60°.

[0011] In some embodiments, the mixer is connected to the mixing pipe, gas pipe, and anode air pipe via clamps, quick-connect fittings, or threads.

[0012] The beneficial effects of this utility model are as follows:

[0013] 1. This utility model sets up an anode air system, an anode gas system, and a cathode air system. The anode air system and the cathode air system are equipped with an anode fan and a cathode fan, respectively. The flow rates of anode air, gas, and cathode air can be independently and precisely controlled, which can meet the gas composition requirements of the fuel cell stack under different operating conditions and improve system efficiency and lifespan.

[0014] 2. The mixer of this utility model is equipped with an impeller, which makes the airflow in the anode air pipe rotate, ensuring that the air and fuel gas are mixed evenly.

[0015] 3. The mixer of this utility model is provided with a gas flow channel, which can increase the flow rate of the gas, prevent the gas and air from separating and failing to mix, and ensure that the gas can smoothly enter the reformer and fuel cell stack. In addition, the faster flow rate of the gas can reflect a certain amount of air, which can reduce the power of the anode blower, thereby improving the efficiency of the system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the anode air system of this utility model;

[0018] Figure 3 This is a schematic diagram of the anode gas system of this utility model;

[0019] Figure 4 This is a schematic diagram of the cathode air system of this utility model;

[0020] Figure 5 This is a schematic diagram of the mixer of this utility model;

[0021] Figure 6 This is a cross-sectional view of the mixer of this utility model.

[0022] Reference numerals: 1. Anode air system; 11. Anode air duct; 12. Anode fan; 13. Anode air flow meter;

[0023] Anode gas system 2; Gas pipeline 21; Mixing pipeline 22; Gas proportional valve 23; Gas flow meter 24; Solenoid valve 25; Mixer 26; Impeller 261; Gas flow channel diameter 262;

[0024] 3. Cathode air system; 31. Cathode air duct; 32. Cathode fan; 33. Cathode air flow meter. Detailed Implementation

[0025] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0026] like Figure 1 As shown, this utility model provides a small solid oxide fuel cell air intake system, including an anode air system 1, an anode fuel gas system 2, and a cathode air system 3, as follows: Figure 3 As shown, the anode gas system 2 includes a gas pipeline 21 and a mixing pipeline 22. One end of the mixing pipeline 22 is connected to the gas pipeline 21, and the other end of the mixing pipeline 22 is used to connect to the reformer. A gas proportional valve 23 and a gas flow meter 24 are installed on the gas pipeline 21, and a solenoid valve 25 is installed on the mixing pipeline 22. Figure 2 As shown, the anode air system 1 includes an anode air duct 11 and an anode fan 12. The anode fan 12 is connected to one end of the anode air duct 11, and the other end of the anode air duct 11 is connected to a mixing duct 22. An anode air flow meter 13 is installed on the anode air duct 11. Figure 4 As shown, the cathode air system 3 includes a cathode air duct 31 and a cathode fan 32. One end of the cathode air duct 31 is connected to the cathode fan 32, and the other end of the cathode air duct 31 is used to connect to the cathode of the fuel cell stack. A cathode air flow meter 33 is installed on the cathode air duct 31.

[0027] Understandably, the cathode fan 32 and cathode air flow meter 33 form a closed-loop control system. Controlling the rotation speed of the cathode fan 32 allows for precise control of the air flow in the cathode air duct 31. Similarly, the gas proportional valve 23 and gas flow meter 24 form a closed-loop control system, allowing for precise control of the gas flow by controlling the opening degree of the gas proportional valve 23. Likewise, the anode fan 12 and anode air flow meter 13 form a closed-loop control system, allowing for precise control of the air flow in the anode air duct 11 by controlling the rotation speed of the anode fan 12. This system can meet the gas composition requirements of the fuel cell stack under different operating conditions, improving system efficiency and lifespan.

[0028] The following is a detailed description of various operating conditions:

[0029] Start-up condition: First, turn on the cathode fan 32 and precisely control the air flow in the cathode air pipe 31 according to the cathode air flow meter 33 to meet the flow requirements under start-up conditions; then, turn on the gas proportional valve 23, adjust the opening of the gas proportional valve 23, and precisely control the gas flow in the gas pipe 21 according to the gas flow meter 24 to meet the flow requirements under start-up conditions; turn on the anode fan 12 and precisely control the air flow in the anode air pipe 11 according to the anode air flow meter 13 to meet the flow requirements under start-up conditions; the gas mixed with air is ignited and combusted in the burner to release heat, and the air entering the fuel cell stack and reformer through the cathode heat exchanger is preheated to reach the target operating temperature, thus completing the start-up.

[0030] Rated operating condition: According to the rated flow requirements, the anode fan 12 and the gas proportional valve 23 control the flow of gas and anode air into the anode. After mixing, the mixture enters the reformer for reforming. Simultaneously, cathode air is introduced, reacting electrochemically with the reformed anode gas to release heat. Unused gas enters the burner for combustion and releases heat. Under these conditions, the fuel cell stack system operates stably. Furthermore, the rotational speed of the cathode fan 32 can be adjusted according to the burner temperature. When the burner temperature is high, the rotational speed of the cathode fan 32 can be increased to increase the cathode air flow and lower the burner temperature. Conversely, when the burner temperature is low, the rotational speed of the cathode fan 32 can be decreased to reduce the cathode air flow and increase the burner temperature.

[0031] Idle condition: The anode blower 12 and the gas proportional valve 23 are kept at rated output. Fuel and air are premixed and combusted at the anode to maintain the stack temperature. The cathode blower 32 is turned off and no air is introduced to the cathode side.

[0032] Purging condition: By adjusting the speed of the anode blower 12 and the opening of the proportional valve, the amount of fuel and air in the anode is controlled. The combustion chamber does not work, and the temperature begins to gradually decrease. After the system cools down to a certain temperature, the blower is turned off first, then the proportional valve is turned off, and finally the solenoid valve 25 is turned off.

[0033] Since the anode fan 12 and the cathode fan 32 are independent of each other, adjusting one of them will not affect the other, thus the ratio of gas to air in the mixing pipe 22 will not be affected under various operating conditions, making it convenient to adjust under various operating conditions.

[0034] In some embodiments, such as Figure 5As shown, the anode gas system 2 includes a mixer 26 with three ports: a first port, a second port, and a third port. The first port of the mixer 26 is connected to the mixing pipe 22, the second port of the mixer 26 is connected to the gas pipe 21, and the third port of the mixer 26 is connected to the anode air pipe 11.

[0035] In some embodiments, such as Figure 5 As shown, an impeller 261 is provided at the third end of the mixer 26, and the air in the anode air pipe 11 enters the mixing pipe 22 through the impeller 261.

[0036] Understandably, under the action of impeller 261, the air entering mixer 26 will rotate, making the mixture of gas and air more uniform, which is beneficial for subsequent reforming.

[0037] In some embodiments, such as Figure 6 As shown, the second end of the mixer 26 is provided with a gas flow channel diameter 262, the diameter of which is smaller than the diameter of the gas pipe 21.

[0038] It should be noted that the flow rate of the natural gas is much smaller than the air flow rate in the anode air duct 11. If the natural gas directly enters the mixer 26, the flow rate will be very low, causing the air and natural gas to separate and fail to mix. Furthermore, the mixed gas cannot enter the reformer or fuel cell stack. Therefore, by setting the gas flow channel diameter 262, the flow rate of the natural gas entering the mixer 26 can be increased, which is beneficial for the mixing of natural gas and air and also prevents the mixed gas from failing to enter the reformer or fuel cell stack. Moreover, the faster-flowing natural gas can diffuse a certain amount of air, reducing the power of the anode blower 12 and thus improving system efficiency. In addition, the diameter of the gas flow channel diameter 262 cannot be too small. If it is too small, the pressure drop when the natural gas enters the mixer 26 will be large, again potentially preventing the mixed gas from entering the reformer or fuel cell stack. Therefore, the diameter of the gas flow channel diameter 262 needs to be determined using CFD analysis based on the natural gas inlet pressure.

[0039] In some embodiments, such as Figure 6 As shown, the impeller 261 is arranged on the end face near the third end of the mixer 26, and the outlet of the gas flow channel 262 is arranged near the middle of the mixer 26.

[0040] Understandably, allowing the air in the anode air pipe 11 to rotate first, and then mixing it with the gas, can further improve the uniformity of the gas and air mixture.

[0041] In some embodiments, such as Figure 1 As shown, the angle between the gas pipeline 21 and the anode air pipeline 11 is an acute angle.

[0042] In some embodiments, the included angle between the gas pipeline 21 and the anode air pipeline 11 is 30° to 60°.

[0043] In some embodiments, the mixer 26 is connected to the mixing pipe 22, the gas pipe 21, and the anode air pipe 11 via a clamp, quick-connect fitting, or thread.

[0044] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A small solid oxide fuel cell intake system, characterized in that: The system includes an anode air system (1), an anode gas system (2), and a cathode air system (3). The anode gas system (2) includes a gas pipeline (21) and a mixing pipeline (22). One end of the mixing pipeline (22) is connected to the gas pipeline (21), and the other end of the mixing pipeline (22) is used to connect to a reformer. A gas proportional valve (23) and a gas flow meter (24) are installed on the gas pipeline (21), and a solenoid valve (25) is installed on the mixing pipeline (22). The anode air system (1) includes an anode air pipeline (11) and an anode fan (12). The anode fan (12) is connected to one end of the anode air duct (11), and the other end of the anode air duct (11) is connected to the mixing duct (22). An anode air flow meter (13) is installed on the anode air duct (11). The cathode air system (3) includes a cathode air duct (31) and a cathode fan (32). One end of the cathode air duct (31) is connected to the cathode fan (32), and the other end of the cathode air duct (31) is used to connect to the cathode of the fuel cell stack. A cathode air flow meter (33) is installed on the cathode air duct (31).

2. The small solid oxide fuel cell intake system according to claim 1, characterized in that: The anode gas system (2) includes a mixer (26), the first end of which is connected to a mixing pipe (22), the second end of which is connected to a gas pipe (21), and the third end of which is connected to an anode air pipe (11).

3. The small solid oxide fuel cell intake system according to claim 2, characterized in that: An impeller (261) is provided at the third end of the mixer (26), and the air in the anode air pipe (11) enters the mixing pipe (22) through the impeller (261).

4. The small solid oxide fuel cell intake system according to claim 3, characterized in that: The second end of the mixer (26) is provided with a gas flow channel diameter (262), the diameter of which is smaller than the diameter of the gas pipe (21).

5. The small solid oxide fuel cell intake system according to claim 4, characterized in that: The impeller (261) is arranged on the end face near the third end of the mixer (26), and the outlet of the gas flow channel (262) is arranged near the middle of the mixer (26).

6. The small solid oxide fuel cell intake system according to any one of claims 1 to 5, characterized in that: The angle between the gas pipeline (21) and the anode air pipeline (11) is an acute angle.

7. The small solid oxide fuel cell intake system according to claim 6, characterized in that: The included angle between the gas pipeline (21) and the anode air pipeline (11) is 30° to 60°.

8. The small solid oxide fuel cell intake system according to any one of claims 2 to 5, characterized in that: The mixer (26) is connected to the mixing pipe (22), the gas pipe (21), and the anode air pipe (11) via a clamp, quick-connect fitting, or thread.

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