SOFC (Solid Oxide Fuel Cell) system

Abstract

The utility model relates to the technical field of solid oxide fuel cells, in particular to a solid oxide fuel cell (SOFC) system which comprises an anode gas inlet system, a cathode gas inlet system, a catalytic burner and a heat exchanger, a reformer and an electric pile are arranged in the catalytic burner, the reformer is connected with an anode of the electric pile, and the cathode gas inlet system is connected with a cathode of the electric pile. The anode gas inlet system comprises a gas pipeline, an anode air pipeline and a mixing cavity, the gas pipeline and the anode air pipeline are respectively connected with the mixing cavity, the mixing cavity is connected with the reformer, a gas outlet of the catalytic burner is connected with the heat exchanger, and the cathode gas inlet system is connected with a cathode of the electric pile through the heat exchanger. The utility model has the advantages of short starting time and simple integral structure.

Description

TECHNICAL FIELD

[0001] The utility model relates to solid oxide fuel cell technical field, concretely relates to a SOFC fuel cell system. BACKGROUND

[0002] Compared with other types of fuel cells, solid oxide fuel cell (SOFC) has higher energy conversion efficiency, but the SOFC working temperature is relatively high, generally at 600-800 DEG C. In order to reach and maintain the temperature, the power generation system is relatively complex.

[0003] The Chinese invention patent application with the application publication number CN115036528A discloses a SOFC system combined with an anode tail gas catalytic combustor and a partial oxidation reforming device, which adopts ATO instead of a flame combustor. Compared with the flame combustor, ATO can realize stable combustion under multiple working conditions, variable working conditions and a large excess air coefficient, ensuring the stable operation of the SOFC system under the modes of temperature rise, load pulling, full load and load reduction. Secondly, the ATO+CPOX mode is adopted, which reduces the target preheating temperature of the starting electric heater from 700 DEG C to 200 DEG C, which can significantly reduce the size and power of the electric heater. However, the SOFC system structure is complex, and the starting electric heater and partial catalytic oxidizer auxiliary system are needed to reach the working temperature, and the SOFC system is only suitable for steam reforming and is not suitable for partial oxidation reforming. UTILITY MODEL CONTENT

[0004] The utility model aims at the defects of prior art, and provides a SOFC fuel cell system, which has short starting time and simple overall structure.

[0005] In order to solve the above technical problems, the utility model provides a SOFC fuel cell system, which comprises an anode gas inlet system, a cathode gas inlet system, a catalytic combustor and a heat exchanger. The catalytic combustor is provided with a reformer and a stack. The reformer is connected with the anode of the stack. The anode gas inlet system comprises a fuel gas pipeline, an anode air pipeline and a mixing chamber. The fuel gas pipeline and the anode air pipeline are connected with the mixing chamber respectively. The mixing chamber is connected with the reformer. The gas outlet of the catalytic combustor is connected with the heat exchanger. The cathode gas inlet system is connected with the cathode of the stack through the heat exchanger.

[0006] In some embodiments, the anode gas inlet system comprises an anode fan and an anode air flowmeter. The air outlet of the anode fan is connected with the anode air pipeline. The anode air flowmeter is arranged on the anode air pipeline.

[0007] In some embodiments, the cathode air inlet system comprises a cathode air pipe, a cathode air blower, and a cathode air flow meter, the outlet of the cathode air blower is connected with the cathode air pipe, and the cathode air flow meter is arranged on the cathode air pipe.

[0008] In some embodiments, air filters are arranged at the air inlets of the anode air blower and the cathode air blower.

[0009] In some embodiments, the anode air inlet system comprises a compressed gas tank and a proportional valve, and a fuel flow meter is arranged on a gas pipe connected with the compressed gas tank.

[0010] In some embodiments, the heat exchanger is arranged inside the catalytic combustor.

[0011] In some embodiments, a combustion chamber is arranged in the catalytic combustor, the electric pile is connected with the air inlet of the combustion chamber, and the air outlet of the combustion chamber is connected with the heat exchanger.

[0012] In some embodiments, a temperature sensor is arranged in the catalytic combustor, the temperature sensor is connected with a PLC controller, and the PLC controller is used to control the rotating speed of the cathode air blower according to the temperature in the catalytic combustor.

[0013] In some embodiments, an electromagnetic valve is arranged on the pipe connected with the reformer and the mixing cavity.

[0014] In some embodiments, the catalytic combustor comprises a box body, a heat preservation layer is arranged on the inner wall of the box body, and the reformer and the electric pile are fixedly arranged in the box body.

[0015] The SOFC fuel cell system has the advantages that:

[0016] 1. The electric pile and the reformer are arranged in the catalytic combustor, fuel and air are input into the catalytic combustor through the anode air inlet system, the fuel is burned to release heat in the catalytic combustor, a large amount of heat generated by the burning is directly transferred to the reformer and the electric pile, and the reformer and the electric pile are forced to rapidly heat to respective working temperatures, and the starting time of the SOFC fuel cell system is not more than 5 min.

[0017] 2. The proportional valve, the fuel flow meter, and the anode air blower are arranged, the fuel flow and the anode air flow can be accurately controlled, the oxygen-carbon ratio of the reformed gas after the air and the fuel are mixed is controlled to be 1.1-1.2, the reformed reaction can be ensured to proceed, the fuel utilization rate can be ensured, and the energy conversion efficiency of the system is improved.

[0018] 3. The utility model discloses a cathode fan is arranged separately, can according to the temperature in catalytic combustor adjust the speed of cathode fan at any time, when temperature is too high, increase the speed of cathode fan, increase flow, reduce the temperature in catalytic combustor, when temperature is too low, reduce the speed of cathode fan, reduce flow, improve the temperature in catalytic combustor. Ultimately realize the temperature control in the reasonable interval range of normal work of electric pile. And relative to anode air and cathode air adopt a fan control, the adjustment of cathode fan will not influence anode air flow, avoided the influence to the oxygen carbon ratio of reforming gas.

[0019] 4. The heat exchanger of the utility model is arranged in the catalytic combustor, is favorable for the quick heating of heat exchanger, further shortens the system starting time. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the structure connection schematic diagram of the utility model.

[0021] Figure mark: catalytic combustor 1;Reformer 2;Electric pile 3;Fuel gas pipeline 4;Compressed gas tank 5;Proportional valve 6;Fuel flowmeter 7;Anode air pipeline 8;Anode fan 9;Anode air flowmeter 10;Cathode air pipeline 11;Cathode fan 12;Cathode air flowmeter 13;Mixing cavity 14;Heat exchanger 15;Air filter 16;Solenoid valve 17. DETAILED DESCRIPTION

[0022] In order to make the technical problem of the present application, technical scheme and beneficial effect more clearly, the following is combined with the embodiment, and the present application is further detailed. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

[0023] As Figure 1 The utility model provides a SOFC fuel cell system, including anode gas system, cathode gas system, catalytic combustor 1 and heat exchanger 15, sets up reformer 2 and electric pile 3 in catalytic combustor 1, and the anode of reformer 2 is connected with electric pile 3, and anode gas system includes fuel gas pipeline 4, anode air pipeline 8, mixing cavity 14, fuel gas pipeline 4, anode air pipeline 8 is connected with mixing cavity 14 respectively, and mixing cavity 14 is connected with reformer 2, and the gas outlet of catalytic combustor 1 is connected with heat exchanger 15, and cathode gas system is connected with the cathode of electric pile 3 through heat exchanger 15.

[0024] It should be noted that the catalytic combustor 1 is a large box, and the reformer 2 and the stack 3 are arranged in the box. When the fuel and air in the mixing chamber 14 pass through the stack 3 into the catalytic combustor 1, the fuel and air are ignited and generate a large amount of heat under the action of the igniter. The heat is transferred to the reformer 2 and the stack 3, so that the reformer 2 and the stack 3 are rapidly heated, thereby greatly reducing the start-up time. In addition, an insulation layer can be arranged on the inner wall of the box to reduce heat loss.

[0025] In some embodiments, the heat exchanger 15 is arranged in the catalytic combustor 1.

[0026] It can be understood that the heat exchanger 15 arranged in the catalytic combustor 1 can improve the heating rate of the heat exchanger 15 and make the heat exchanger 15 quickly reach the working temperature.

[0027] In some embodiments, the anode air inlet system includes the anode fan 9 and the anode air flow meter 10. The air outlet of the anode fan 9 is connected with the anode air pipeline 8, and the anode air flow meter 10 is arranged on the anode air pipeline 8.

[0028] In some embodiments, the anode air inlet system includes the compressed gas tank 5, the proportional valve 6, and the fuel flow meter 7. The proportional valve 6 and the fuel flow meter 7 are arranged on the fuel pipeline 4, and the compressed gas tank 5 is connected with the fuel pipeline 4.

[0029] It can be understood that by arranging the proportional valve 6, the fuel flow meter 7, and the anode fan 9, the fuel flow and the anode air flow can be accurately controlled, so that the oxygen-carbon ratio of the reforming gas after the air and the fuel are mixed is controlled to be 1.1-1.2. The reforming reaction can be ensured to proceed, the fuel utilization rate can be ensured, and the energy conversion efficiency of the system is improved.

[0030] In some embodiments, the cathode air inlet system includes the cathode air pipeline 11, the cathode fan 12, and the cathode air flow meter 13. The air outlet of the cathode fan 12 is connected with the cathode air pipeline 11, and the cathode air flow meter 13 is arranged on the cathode air pipeline 11.

[0031] It can be understood that by arranging the cathode fan 12, the speed of the cathode fan 12 can be adjusted at any time according to the temperature in the catalytic combustor 1. That is, when the temperature is too high, the speed of the cathode fan 12 is increased, the flow is increased, and the temperature in the catalytic combustor 1 is reduced. When the temperature is too low, the speed of the cathode fan 12 is reduced, the flow is reduced, and the temperature in the catalytic combustor 1 is increased. Finally, the temperature is controlled in a reasonable range in which the stack 3 normally operates.

[0032] In addition, the air inlet of the cathode air pipeline 11 and the anode air pipeline 8 is controlled by the cathode fan 12 and the anode fan 9 respectively, so that the air flow in the cathode air pipeline 11 is adjusted without affecting the air flow in the anode air pipeline 8, and the oxygen-carbon ratio of the reforming gas is ensured unchanged.

[0033] In some embodiments, the air inlet of the anode fan 9 and the cathode fan 12 is provided with an air filter 16.

[0034] In some embodiments, a combustion chamber is arranged in the catalytic combustor 1, the air inlet of the combustion chamber is connected with the electric pile 3, and the air outlet of the combustion chamber is connected with the heat exchanger 15.

[0035] In some embodiments, a temperature sensor is arranged in the catalytic combustor 1, the temperature sensor is connected with the PLC controller, and the PLC controller is used for controlling the rotating speed of the cathode fan 12 according to the temperature in the catalytic combustor 1.

[0036] In some embodiments, an electromagnetic valve 17 is arranged on the pipeline connected with the reformer 2.

[0037] The working principle of the SOFC fuel cell system is as follows:

[0038] 1, start-up condition - temperature rise

[0039] Firstly, the anode fan 9 and the electromagnetic valve 17 are started, and the system pipeline, especially the cavity of the catalytic combustor 1, is purged with air, so as to dilute the fuel in the system pipeline as much as possible and avoid the risk of deflagration in the subsequent ignition;

[0040] Secondly, after 2 to 4 purging is completed, the proportional valve 6 is started, and feedback closed-loop control is performed through the fuel flow meter 7, so as to accurately control the fuel supply amount; the fuel is mixed with air in the catalytic combustor 1;

[0041] Thirdly, the ignition device is powered on to make the fuel in the catalytic combustor 1 burn and release heat, and the heat is transmitted to the reformer 2, the electric pile 3 and the heat exchanger 15, so as to force them to rise to the respective working temperatures;

[0042] Fourthly, after the temperature reaches the set temperature, the reformer 2 starts to work, and the fuel in the reformer 2 is subjected to a reforming reaction (for example, methane oxidation reforming): CH4+1 / 2O2→CO+2H2, and the hydrogen generated by the reforming enters the anode cavity of the electric pile 3;

[0043] Fifth step, start the cathode blower 12, air first into the heat exchanger 15 for preheating, preheated air into the cathode cavity of the stack 3, at this time the stack 3 in the third step has been heated to the working temperature, the hydrogen of the anode and the air of the cathode in the stack 3 electrochemical reaction: H2+1 / 2O2→H2O, and output power, thus the system startup is completed.

[0044] Unreformed fuel, reforming of CO and H2 not used by the stack 3 will continue to enter the catalytic combustor 1, they are combusted in the catalytic combustor 1 to maintain system operating temperature.

[0045] 2, operating condition-temperature control

[0046] For the electrochemical reaction in the stack 3, the air supplied by the cathode blower 12 is excessive, the excess air is mainly used for temperature adjustment when the system is working normally.

[0047] When the temperature is too high, increase the speed of the cathode blower 12, increase the flow, reduce the temperature in the catalytic combustor 1; when the temperature is too low, reduce the speed of the cathode blower 12, reduce the flow, increase the temperature in the catalytic combustor 1. Ultimately realize the temperature control in the reasonable range of the normal working of the stack 3.

[0048] 3, precise control of fuel and control of the anode blower 9

[0049] Fuel side flow is controlled by fuel flow meter 7 and proportional valve 6 to realize closed loop feedback control, to avoid the risk of explosion when the system starts to ignite, further, cooperate with the control of the anode blower 9, control the oxygen-carbon ratio to 1.1-1.2 by controlling the fuel flow and the anode air flow, which can ensure the reforming reaction and ensure the fuel utilization rate, improve the energy conversion efficiency of the system.

[0050] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. An SOFC fuel cell system, characterized in that: The device includes an anode air intake system, a cathode air intake system, a catalytic burner (1), and a heat exchanger (15). The catalytic burner (1) is equipped with a reformer (2) and an electric stack (3). The reformer (2) is connected to the anode of the electric stack (3). The anode air intake system includes a gas pipeline (4), an anode air pipeline (8), and a mixing chamber (14). The gas pipeline (4) and the anode air pipeline (8) are respectively connected to the mixing chamber (14). The mixing chamber (14) is connected to the reformer (2). The outlet of the catalytic burner (1) is connected to the heat exchanger (15). The cathode air intake system is connected to the cathode of the electric stack (3) through the heat exchanger (15).

2. The SOFC fuel cell system according to claim 1, characterized in that: The anode air intake system includes an anode fan (9) and an anode air flow meter (10). The outlet of the anode fan (9) is connected to the anode air duct (8), and the anode air flow meter (10) is arranged on the anode air duct (8).

3. The SOFC fuel cell system according to claim 2, characterized in that: The cathode air intake system includes a cathode air duct (11), a cathode fan (12), and a cathode air flow meter (13). The outlet of the cathode fan (12) is connected to the cathode air duct (11), and the cathode air flow meter (13) is arranged on the cathode air duct (11).

4. The SOFC fuel cell system according to claim 3, characterized in that: Air filters (16) are installed at the air inlets of both the anode fan (9) and the cathode fan (12).

5. The SOFC fuel cell system according to any one of claims 1 to 4, characterized in that: The anode air intake system includes a compressed air tank (5), a proportional valve (6), and a fuel flow meter (7). The proportional valve (6) and the fuel flow meter (7) are arranged on the gas pipeline (4), and the compressed air tank (5) is connected to the gas pipeline (4).

6. The SOFC fuel cell system according to any one of claims 1 to 4, characterized in that: The heat exchanger (15) is arranged inside the catalytic burner (1).

7. The SOFC fuel cell system according to any one of claims 1 to 4, characterized in that: The catalytic burner (1) is provided with a combustion chamber, the fuel cell stack (3) is connected to the air inlet of the combustion chamber, and the air outlet of the combustion chamber is connected to the heat exchanger (15).

8. The SOFC fuel cell system according to claim 3 or 4, characterized in that: A temperature sensor is installed inside the catalytic burner (1), and the temperature sensor is connected to a PLC controller. The PLC controller is used to control the rotation speed of the cathode fan (12) according to the temperature inside the catalytic burner (1).

9. The SOFC fuel cell system according to any one of claims 1 to 4, characterized in that: A solenoid valve (17) is installed on the pipe connecting the mixing chamber (14) and the reformer (2).

10. The SOFC fuel cell system according to claim 7, characterized in that: The catalytic burner (1) includes a housing with an insulation layer on the inner wall of the housing, and the reformer (2) and the fuel cell stack (3) are fixedly installed inside the housing.

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