A solid oxide fuel cell system model

Abstract

The present invention discloses a solid oxide fuel cell system model, comprising a stack, a combustion chamber, a fuel pipeline, an air pipeline, a blower, a fuel heat exchanger, and an air heat exchanger; the inlet end of the fuel pipeline is connected to a fuel source, the inlet end of the air pipeline is connected to the blower, the outlet end of the fuel pipeline is connected to the inlet end of the anode side of the stack through a first heat exchange channel of the fuel heat exchanger; the outlet end of the air pipeline is connected to the inlet end of the cathode side of the stack through the first heat exchange channel of the air heat exchanger; the outlet end of the anode side of the stack is connected to the inlet end of the combustion chamber, and the outlet end of the cathode side of the stack is connected to the inlet end of the combustion chamber; the outlet end of the combustion chamber is connected to the inlet end of the second heat exchange channel of the fuel heat exchanger, and the outlet end of the second heat exchange channel of the fuel heat exchanger is connected to the inlet end of the second heat exchange channel of the air heat exchanger. The present invention has the advantages of simple structure, stable and efficient, safe and reliable, high thermal energy utilization rate, energy saving and environmental protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid oxide fuel cells, and in particular relates to a solid oxide fuel cell system model. Background Art

[0002] The existing solid oxide fuel cell system model is widely used in various fuel cell enterprises, research institutes or other institutions that need to conduct dynamic and static performance analysis, system optimization analysis, risk assessment, etc. of solid oxide fuel cells.

[0003] Existing solid oxide fuel cell system models are usually composed of a chemical stack as the core, supplemented by a combustion chamber, fuel heat exchanger, air heat exchanger, blower, sensor, flow monitor, gas transmission pipeline, and electronic control unit. Among them, the gas transmission pipeline is usually composed of two air inlet pipes, the air pipe and the fuel pipe. After entering the system, the air and fuel (such as hydrogen) are heated through their own independent heat exchangers and then directly enter the stack to participate in the electrochemical reaction. At the same time, the air flow and fuel flow are adjusted to adjust the stack discharge operating temperature. However, this solid oxide fuel cell system model generally has the following defects:

[0004] 1. Since air and fuel (such as hydrogen) are directly connected to the fuel cell stack through their own independent air intake pipes and heat exchangers, the exhaust gas from the combustion chamber is discharged after only one heat exchange, resulting in low heat recovery efficiency.

[0005] 2. Since variables such as the initial temperature and flow of the fuel, the initial temperature and flow of the air, and the temperature and flow of the exhaust gas discharged from the combustion chamber all affect the stack discharge operating temperature, it is very difficult to accurately control each parameter within the most effective operating range by only adjusting the air flow and fuel flow as control variables;

[0006] 3. The existing model does not accurately control parameters, especially these parameters will further affect the technical parameters such as the output voltage and output current of the battery stack, thereby affecting the results of subsequent dynamic and static analysis of the system and optimization of the optimal operating point. Summary of the Invention

[0007] The purpose of the present invention is to provide a solid oxide fuel cell system model with simple structure, stable and efficient, safe and reliable, high thermal energy utilization rate, energy saving and environmental protection.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A solid oxide fuel cell system model, which includes a fuel stack, a combustion chamber, a fuel pipeline, an air pipeline, a blower, a fuel heat exchanger and an air heat exchanger; the inlet end of the fuel pipeline is connected to the fuel source, the outlet end of the fuel pipeline is connected to the inlet end of the first heat exchange flow channel of the fuel heat exchanger, the outlet end of the first heat exchange flow channel of the fuel heat exchanger is connected to the inlet end of the anode side of the fuel stack; the inlet end of the air pipeline is connected to the blower, the outlet end of the air pipeline is connected to the inlet end of the first heat exchange flow channel of the air heat exchanger The outlet end of the first heat exchange channel of the air heat exchanger is connected to the inlet end of the cathode side of the fuel cell stack; the outlet end of the anode side of the fuel cell stack is connected to the inlet end of the combustion chamber, and the outlet end of the cathode side of the fuel cell stack is connected to the inlet end of the combustion chamber; the outlet end of the combustion chamber is connected to the inlet end of the second heat exchange channel of the fuel heat exchanger, and the outlet end of the second heat exchange channel of the fuel heat exchanger is connected to the inlet end of the second heat exchange channel of the air heat exchanger; the outlet end of the second heat exchange channel of the air heat exchanger is connected to the exhaust pipe.

[0010] As a preferred embodiment of the present invention, the solid oxide fuel cell system model also includes a bypass pipe, the inlet end of the bypass pipe is connected to the blower, and the outlet end of the bypass pipe is connected to the inlet end of the cathode side of the fuel cell stack; a first flow control valve is provided on the bypass pipe.

[0011] As a preferred embodiment of the present invention, a proportional diverter valve is provided at the outlet end of the combustion chamber, the first outlet end of the proportional diverter valve is connected to the inlet end of the second heat exchange channel of the fuel heat exchanger, and the second outlet end of the proportional diverter valve is connected to the exhaust pipe.

[0012] As a preferred embodiment of the present invention, a first auxiliary heat source is provided on the connecting pipe between the outlet end of the first heat exchange channel of the fuel heat exchanger and the inlet end of the anode side of the fuel cell stack.

[0013] As a preferred embodiment of the present invention, a second auxiliary heat source is provided on the connecting pipe between the outlet end of the first heat exchange channel of the air heat exchanger and the inlet end of the cathode side of the fuel cell stack.

[0014] As a preferred solution of the present invention, the fuel pipeline is connected to a second flow control valve; the air pipeline is connected to a third flow control valve.

[0015] As a preferred embodiment of the present invention, a first temperature detector for monitoring the temperature of fuel entering the stack is provided at the inlet end of the anode side of the stack; a second temperature detector for monitoring the temperature of air entering the stack is provided at the inlet end of the cathode side of the stack.

[0016] As a preferred solution of the present invention, the outlet end of the exhaust pipe is connected to an exhaust gas treatment system.

[0017] As a preferred solution of the present invention, a water tank is connected between the outlet end of the exhaust pipe and the exhaust gas treatment system.

[0018] As a preferred solution of the present invention, the fuel cell stack is connected to a power converter.

[0019] The solid oxide fuel cell system model provided by the present invention has the following beneficial effects compared with the prior art:

[0020] (1) The present invention combines two independent heat exchangers (i.e., the fuel heat exchanger and the air heat exchanger) into one to form a two-stage heat exchanger, so that the fuel and air sequentially exchange heat with the exhaust gas discharged from the combustion chamber. This ensures that the temperature of the fuel entering the fuel stack is always higher than the air temperature, thereby improving the utilization rate of the exhaust gas heat energy and saving energy.

[0021] (2) The present invention, through the arrangement of the bypass pipe and the first flow control valve, can mix and cool the air heated by the air heat exchanger with the cold air from the bypass pipe, so that the temperature of the air entering the fuel cell stack meets the preset electrochemical reaction temperature, thereby adapting to the operating condition where the temperature of the air entering the fuel cell stack is too high;

[0022] (3) The present invention can accurately control the flow rate of exhaust gas involved in heat exchange by setting a proportional diverter valve, and the excess exhaust gas is discharged through the other port of the proportional diverter valve. While ensuring that the temperature of the fuel entering the fuel stack meets the preset electrochemical reaction temperature, it can fully utilize the heat of the exhaust gas and effectively avoid the operating condition where the temperature of the fuel entering the fuel stack is too high;

[0023] (4) The present invention, through the provision of a first auxiliary heat source, can perform secondary auxiliary heating on the fuel after being heated by the fuel heat exchanger, so that the temperature of the fuel entering the fuel stack meets the preset electrochemical reaction temperature, thereby adapting to the operating condition where the temperature of the fuel entering the fuel stack is too low;

[0024] (5) The present invention provides a second auxiliary heat source to perform secondary auxiliary heating on the air after being heated by the air heat exchanger, so that the temperature of the air entering the fuel cell stack meets the preset temperature of the electrochemical reaction, thereby adapting to the working condition where the temperature of the air entering the fuel cell stack is too low.

[0025] It can be seen that the solid oxide fuel cell system model of the present invention can ensure that the temperature of the fuel entering the stack is always greater than the air temperature, which is beneficial to controlling the temperature difference of the gas at the inlet of the stack; at the same time, through the coordinated work of the bypass pipe, flow control valve, proportional diverter valve and auxiliary heat source, the input gas can be better preheated and temperature controlled, so as to achieve precise control of the gas temperature within the most effective working range, thereby improving the output efficiency of the entire fuel cell system, and has the advantages of simple structure, stable and efficient, safe and reliable, high thermal energy utilization, energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments are briefly introduced below.

[0027] Figure 1 is a structural schematic diagram of a solid oxide fuel cell system model according to an embodiment of the present invention;

[0028] Markings in the figure:

[0029] Fuel cell stack 1, combustion chamber 2, fuel pipeline 3; air pipeline 4; blower 5; fuel heat exchanger 6; air heat exchanger 7; exhaust pipeline 8; bypass pipeline 9; first flow control valve 10; proportional diverter valve 11; first auxiliary heat source 12; second auxiliary heat source 13; second flow control valve 14; third flow control valve 15; first temperature detector 16; second temperature detector 17; exhaust gas treatment system 18; water tank 19; power converter 20. DETAILED DESCRIPTION

[0030] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0031] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0032] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0033] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0034] Please also refer to Figure 1 , the solid oxide fuel cell system model provided by the embodiment of the present invention is now described.

[0035] like Figure 1 As shown, the solid oxide fuel cell system model of the embodiment of the present invention includes a fuel cell stack 1, a combustion chamber 2, a fuel pipeline 3, an air pipeline 4, a blower 5, a fuel heat exchanger 6 and an air heat exchanger 7; the inlet end of the fuel pipeline 3 is connected to the fuel source, the outlet end of the fuel pipeline 3 is connected to the inlet end of the first heat exchange channel of the fuel heat exchanger 6, and the outlet end of the first heat exchange channel of the fuel heat exchanger 6 is connected to the inlet end of the anode side of the fuel cell stack 1; the inlet end of the air pipeline 4 is connected to the blower 5, and the outlet end of the air pipeline 4 is connected to the first heat exchange channel of the air heat exchanger 7. The inlet end of the flow channel is connected, the outlet end of the first heat exchange flow channel of the air heat exchanger 7 is connected to the inlet end of the cathode side of the fuel cell stack 1; the outlet end of the anode side of the fuel cell stack 1 is connected to the inlet end of the combustion chamber 2, and the outlet end of the cathode side of the fuel cell stack 1 is connected to the inlet end of the combustion chamber 2; the outlet end of the combustion chamber 2 is connected to the inlet end of the second heat exchange flow channel of the fuel heat exchanger 6, and the outlet end of the second heat exchange flow channel of the fuel heat exchanger 6 is connected to the inlet end of the second heat exchange flow channel of the air heat exchanger 7; the outlet end of the second heat exchange flow channel of the air heat exchanger 7 is connected to the exhaust pipe 8.

[0036] When the system is running, the fuel source feeds fuel into the system (the fuel is generally fuel, but can also be other combustible gases), the fuel enters the fuel heat exchanger 6 through the fuel pipe 3, and performs heat exchange with the exhaust gas discharged from the combustion chamber 2. After the fuel is heated, it enters the anode side of the fuel stack 1 to participate in the electrochemical reaction; the blower 5 feeds air into the system, and the air enters the air heat exchanger 7 through the air pipe 4, and performs heat exchange with the exhaust gas discharged from the fuel heat exchanger 6. After the air is heated, it enters the cathode side of the fuel stack 1 to participate in the electrochemical reaction. It can be seen that the present invention combines two independent heat exchangers (i.e., the fuel heat exchanger 6 and the air heat exchanger 7) into one to form a two-stage heat exchanger, so that the fuel and air can sequentially exchange heat with the exhaust gas discharged from the combustion chamber 2, so that the temperature of the fuel entering the fuel stack 1 is always greater than the air temperature (but the temperature difference does not exceed 200K), thereby improving the utilization rate of the exhaust gas heat energy and saving energy.

[0037] Furthermore, in order to ensure that the temperature of the fuel and the temperature of the air entering the fuel cell stack 1 meet the preset electrochemical reaction temperature, the solid oxide fuel cell system model also includes a bypass pipe 9, the inlet end of the bypass pipe 9 is connected to the blower 5, and the outlet end of the bypass pipe 9 is connected to the inlet end of the cathode side of the fuel cell stack 1; the bypass pipe 9 is provided with a first flow control valve 10. The outlet end of the combustion chamber 2 is provided with a proportional diverter valve 11, the first outlet end of the proportional diverter valve 11 is connected to the inlet end of the second heat exchange channel of the fuel heat exchanger 6, and the second outlet end of the proportional diverter valve 11 is connected to the exhaust pipe 8. A first auxiliary heat source 12 is provided on the connecting pipe between the outlet end of the first heat exchange channel of the fuel heat exchanger 6 and the inlet end of the anode side of the fuel cell stack 1. A second auxiliary heat source 13 is provided on the connecting pipe between the outlet end of the first heat exchange channel of the air heat exchanger 7 and the inlet end of the cathode side of the fuel cell stack 1. Therefore, for different working conditions, the specific operations are as follows:

[0038] (1) When the exhaust gas discharged from the combustion chamber 2 is sufficient or the temperature reaches the standard so that the temperature of the fuel entering the fuel cell stack 1 meets the preset electrochemical reaction temperature, the first auxiliary heat source 12 is turned off, and the flow rate of the exhaust gas participating in the heat exchange is accurately controlled by the proportional diverter valve 11, and the excess exhaust gas is discharged through the other port of the proportional diverter valve 11;

[0039] (2) When the exhaust gas discharged from the combustion chamber 2 is insufficient or the temperature does not meet the standard, so that the temperature of the fuel entering the fuel stack 1 is lower than the preset electrochemical reaction temperature, the proportional diverter valve 11 will no longer flow air, and all the exhaust gas will participate in the heat exchange. The first auxiliary heat source 12 is turned on to perform secondary auxiliary heating on the fuel that is not hot enough after heat exchange in the fuel heat exchanger 6, so that the temperature of the fuel entering the fuel stack 1 meets the preset electrochemical reaction temperature;

[0040] (3) When the exhaust gas discharged from the combustion chamber 2 is sufficient or the temperature meets the standard so that the temperature of the fuel entering the fuel cell stack 1 meets the preset electrochemical reaction temperature, but the temperature of the air entering the fuel cell stack 1 is too high, the second auxiliary heat source 13 is turned off, and the first flow control valve 10 is adjusted to allow the air heated by the air heat exchanger 7 to mix with the cold air from the bypass pipe 9 to cool down, so that the temperature of the air entering the fuel cell stack 1 meets the preset electrochemical reaction temperature;

[0041] (4) When the exhaust gas discharged from the combustion chamber 2 is sufficient or the temperature meets the standard so that the temperature of the fuel entering the fuel cell stack 1 meets the preset electrochemical reaction temperature, but the temperature of the air entering the fuel cell stack 1 is too low, the first flow control valve 10 is closed and the second auxiliary heat source 13 is opened to perform secondary auxiliary heating on the air heated by the air heat exchanger 7 so that the temperature of the air entering the fuel cell stack 1 meets the preset electrochemical reaction temperature;

[0042] (5) When the exhaust gas discharged from the combustion chamber 2 is insufficient or the temperature does not meet the standard, so that the temperature of the fuel and the temperature of the air entering the fuel stack 1 are both lower than the preset electrochemical reaction temperature, the proportional diverter valve 11 will no longer flow air, and all the exhaust gas will participate in the heat exchange. The first auxiliary heat source 12 is turned on to perform secondary auxiliary heating on the fuel that is not hot enough after heat exchange in the fuel heat exchanger 6, so that the temperature of the fuel entering the fuel stack 1 meets the preset electrochemical reaction temperature; the second auxiliary heat source 13 is turned on to perform secondary auxiliary heating on the air that is not hot enough after heat exchange in the air heat exchanger 7, so that the temperature of the air entering the fuel stack 1 meets the preset electrochemical reaction temperature.

[0043] (6) When the exhaust gas discharged from the combustion chamber 2 is insufficient or the temperature does not meet the standard so that the temperature of the fuel entering the fuel stack 1 is lower than the preset electrochemical reaction temperature, but the temperature of the air entering the fuel stack 1 is too high, the proportional diverter valve 11 will no longer flow air, and all the exhaust gas will participate in the heat exchange, and the first auxiliary heat source 12 will be turned on to perform secondary auxiliary heating on the fuel that is not hot enough after heat exchange in the fuel heat exchanger 6, so that the temperature of the fuel entering the fuel stack 1 meets the preset electrochemical reaction temperature; the second auxiliary heat source 13 will be closed, and the first flow control valve 10 will be adjusted to allow the air heated by the air heat exchanger 7 to mix with the cold air from the bypass pipe 9 to cool down, so that the temperature of the air entering the fuel stack 1 meets the preset electrochemical reaction temperature.

[0044] For example, in order to precisely control the fuel flow and the air flow, the fuel pipeline 3 is connected to a second flow control valve 14 ; the air pipeline 4 is connected to a third flow control valve 15 .

[0045] Exemplarily, a first temperature detector 16 for monitoring the temperature of fuel entering the fuel stack 1 is provided at the inlet end of the anode side of the fuel stack 1; a second temperature detector 17 for monitoring the temperature of air entering the fuel stack 1 is provided at the inlet end of the cathode side of the fuel stack 1.

[0046] Exemplarily, the outlet end of the exhaust pipe 8 is connected to an exhaust gas treatment system 18 to achieve the purpose of emission reduction.

[0047] For example, a water tank 19 is connected between the outlet end of the exhaust pipe 8 and the exhaust gas treatment system 18. Thus, the exhaust gas discharged from the air heat exchanger 7 and the exhaust gas diverted by the proportional diverter valve 11 are combined and connected to the water tank 19, thereby heating the water in the water tank 19 and achieving efficient utilization of thermal energy.

[0048] For example, the fuel cell stack 1 is connected to a power converter 20. Thus, the voltage and current generated by the electrochemical reaction in the fuel cell stack 1 are stably supplied to the external load after being loaded by the power converter 20.

[0049] To sum up, the solid oxide fuel cell system model of the embodiment of the present invention can ensure that the temperature of the fuel entering the stack 1 is always greater than the air temperature, which is beneficial to controlling the temperature difference of the gas at the inlet of the stack 1; at the same time, through the coordinated work of the bypass pipe 9, the flow control valve, the proportional diverter valve 11 and the auxiliary heat source, the input gas can be better preheated and temperature controlled, so as to achieve precise control of the gas temperature within the most effective working range, thereby improving the output efficiency of the entire fuel cell system, and has the advantages of simple structure, stable and efficient, safe and reliable, high thermal energy utilization, energy saving and environmental protection.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A solid oxide fuel cell system model, characterized in that: The invention comprises a fuel cell stack, a combustion chamber, a fuel pipeline, an air pipeline, a blower, a fuel heat exchanger and an air heat exchanger; the inlet end of the fuel pipeline is connected to the fuel source, the outlet end of the fuel pipeline is connected to the inlet end of the first heat exchange flow channel of the fuel heat exchanger, the outlet end of the first heat exchange flow channel of the fuel heat exchanger is connected to the inlet end of the anode side of the fuel cell stack; the inlet end of the air pipeline is connected to the blower, the outlet end of the air pipeline is connected to the inlet end of the first heat exchange flow channel of the air heat exchanger, and the air exchanger is connected to the inlet end of the first heat exchange flow channel of the air heat exchanger. The outlet end of the first heat exchange flow channel of the heat exchanger is connected to the inlet end of the cathode side of the fuel cell stack; the outlet end of the anode side of the fuel cell stack is connected to the inlet end of the combustion chamber, and the outlet end of the cathode side of the fuel cell stack is connected to the inlet end of the combustion chamber; the outlet end of the combustion chamber is connected to the inlet end of the second heat exchange flow channel of the fuel heat exchanger, and the outlet end of the second heat exchange flow channel of the fuel heat exchanger is connected to the inlet end of the second heat exchange flow channel of the air heat exchanger; the outlet end of the second heat exchange flow channel of the air heat exchanger is connected to the exhaust pipe; It also includes a bypass pipe, the inlet end of the bypass pipe is connected to the blower, and the outlet end of the bypass pipe is connected to the inlet end of the cathode side of the fuel cell stack; the bypass pipe is provided with a first flow control valve; A proportional diverter valve is provided at the outlet end of the combustion chamber, a first outlet end of the proportional diverter valve is connected to the inlet end of the second heat exchange flow channel of the fuel heat exchanger, and a second outlet end of the proportional diverter valve is connected to the exhaust pipe; A first auxiliary heat source is provided on the connecting pipe between the outlet end of the first heat exchange channel of the fuel heat exchanger and the inlet end of the anode side of the fuel cell stack; A second auxiliary heat source is provided on the connecting pipe between the outlet end of the first heat exchange channel of the air heat exchanger and the inlet end of the cathode side of the fuel cell stack.

2. The solid oxide fuel cell system model according to claim 1, characterized in that: The fuel pipeline is connected to a second flow control valve; the air pipeline is connected to a third flow control valve.

3. The solid oxide fuel cell system model according to claim 1, characterized in that: A first temperature detector for monitoring the temperature of fuel entering the stack is provided at the inlet end of the anode side of the stack; a second temperature detector for monitoring the temperature of air entering the stack is provided at the inlet end of the cathode side of the stack.

4. The solid oxide fuel cell system model according to claim 1, characterized in that: The outlet end of the exhaust pipe is connected to an exhaust gas treatment system.

5. The solid oxide fuel cell system model according to claim 4, characterized in that: A water tank is connected between the outlet end of the exhaust pipe and the tail gas treatment system.

6. The solid oxide fuel cell system model according to any one of claims 1 to 5, characterized in that: The battery stack is connected to a power converter.

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