A medium-temperature fuel cell carbon cycle power generation device based on solar energy and a carbon deposition treatment method thereof

Abstract

The invention discloses a medium-temperature fuel cell carbon cycle power generation device based on solar energy, comprising a solar energy absorption and conversion device, a carbon reaction chamber, a mixed gas separation device and a solid oxide fuel cell; the carbon reaction chamber generates carbon monoxide by utilizing heat energy after being filled with carbon dioxide, the exhaust port of the carbon reaction chamber is connected to the mixed gas separation device, the mixed gas separation device separates the carbon monoxide and carbon dioxide discharged from the carbon reaction chamber, the separated carbon monoxide is sent to the anode of the solid oxide fuel cell, and the separated carbon dioxide is output through two branches, branch I is connected to the carbon reaction chamber, branch II is connected to the anode of the solid oxide fuel cell, and an electric control valve is arranged on branch II; the solid oxide fuel cell generates carbon dioxide and electric energy by utilizing carbon monoxide, and the generated carbon dioxide is sent to the carbon reaction chamber; a controller is also included, the electric control valve is connected to the controller through a cable, and the controller collects the voltage at both ends of the solid oxide fuel cell through a voltage sensor.

Description

Technical Field

[0001] The present invention relates to a new energy power generation device, in particular to a medium-temperature fuel cell carbon cycle power generation device based on solar energy, and also to a carbon deposit treatment method of the above medium-temperature fuel cell carbon cycle power generation device based on solar energy. Background Art

[0002] Fuel cells are clean and efficient power generation devices. In fuel cell systems, solid oxide fuel cells have the advantages of solid structure, no need for precious metal catalysts, and a wide range of fuel selection, and have received widespread attention in recent years. However, solid oxide fuel cells have not yet been commercialized. The most important factor is that the system operating temperature is high, which leads to chemical reactions between the electrode and the electrolyte contact surface, and the high temperature brings many problems to the sealing process. Therefore, in recent years, many studies have focused on reducing the operating temperature of solid oxide fuel cells. Summary of the invention

[0003] Purpose of the invention: The technical problem to be solved by the present invention is to provide a medium-temperature fuel cell carbon cycle power generation device based on solar energy. The power generation device starts from the fuel cell technology, uses carbon as raw material, forms a carbon cycle closed loop, and the heat energy required in the system is the heat utilization of solar energy, thereby obtaining a clean and environmentally friendly power generation device.

[0004] Another technical problem to be solved by the present invention is to provide a method for treating carbon deposits in the above-mentioned solar-based medium-temperature fuel cell carbon cycle power generation device. This method uses carbon dioxide to eliminate carbon deposits on the anode of the solid oxide fuel cell, which can ensure long-term, effective and stable operation of the system.

[0005] Invention content: In order to achieve the above invention purpose, the technical solution adopted by the present invention is:

[0006] A medium-temperature fuel cell carbon cycle power generation device based on solar energy comprises a solar energy absorption conversion device, a carbon reaction chamber, a mixed gas separation device and a solid oxide fuel cell; the solar energy absorption conversion device supplies heat energy to the carbon reaction chamber, the mixed gas separation device and the solid oxide fuel cell respectively through a heat exchanger; the carbon reaction chamber generates carbon monoxide by using heat energy after being filled with carbon dioxide, the exhaust port of the carbon reaction chamber is connected to the mixed gas separation device, the mixed gas separation device separates the carbon monoxide and carbon dioxide discharged from the carbon reaction chamber, the separated carbon monoxide is sent to the solid oxide fuel cell through a carbon monoxide delivery pipeline, the separated carbon dioxide is discharged through a carbon dioxide delivery pipeline, the carbon dioxide delivery pipeline is divided into two branches, branch I is connected to the carbon reaction chamber, branch II is connected to the solid oxide fuel cell anode, and branch II is provided with an electric control valve; the solid oxide fuel cell generates carbon dioxide and electric energy by using carbon monoxide, the generated carbon dioxide is sent to the carbon reaction chamber, and the generated electric energy is supplied to an external load; a controller is also included, the electric control valve is connected to the controller through a cable, and the controller collects the voltage at both ends of the solid oxide fuel cell through a voltage sensor.

[0007] Among them, the solar energy absorption and conversion device includes a solar reflector group, a solar collector, a solar heat exchanger and a heat storage device. The solar reflector group reflects the sunlight and focuses it on the solar collector. The heat energy in the solar collector is stored in the heat storage device through the solar heat exchanger.

[0008] Among them, the heat exchanger includes a separation heat exchanger, a fuel cell stack heat exchanger and a carbon reaction chamber heat exchanger. The heat energy output end of the heat storage is respectively connected to the heat energy input end of the separation heat exchanger, the fuel cell stack heat exchanger and the carbon reaction chamber heat exchanger. The heat energy output end of the separation heat exchanger is connected to the mixed gas separation device, the heat energy output end of the fuel cell stack heat exchanger is connected to the solid oxide fuel cell, and the heat energy output end of the carbon reaction chamber heat exchanger is connected to the carbon reaction chamber.

[0009] The carbon reaction chamber contains solid coal, and the filling amount of the coal is more than 3 / 4 of the volume of the cavity of the carbon reaction chamber.

[0010] The mixed gas separation device includes a molten carbonate fuel cell and a water-gas separator located at the gas outlet of the anode plate of the molten carbonate fuel cell; the molten carbonate fuel cell is connected in parallel with the solid oxide fuel cell to supply power to an external load, that is, the cathode of the molten carbonate fuel cell is connected in parallel with the negative electrode of the solid oxide fuel cell through a wire, and the anode of the molten carbonate fuel cell is connected in parallel with the positive electrode of the solid oxide fuel cell through a wire. The water-gas separator is used to separate CO2, H2O and unreacted H2, and the unreacted H2 is returned to the anode of the molten carbonate fuel cell through the gas path and the anode plate inlet for reuse.

[0011] The anode of the molten carbonate fuel cell is metallic nickel; the cathode is lithium nickel oxide; the electrolyte layer is a mixture of carbonates Li2CO3 and K2CO3; the mass percentage of Li2CO3 is 62% and the mass percentage of K2CO3 is 38%.

[0012] The exhaust port of the carbon reaction chamber is connected to the cathode plate air inlet of the molten carbonate fuel cell, and the cathode plate air inlet is also connected to an external oxygen tank through a branch pipe. Carbon dioxide reacts with oxygen at the cathode of the molten carbonate fuel cell to generate CO3 2- Ions, CO3 2- The ions pass through the electrolyte layer and react with H2 at the anode to generate H2O and CO2. After H2O and CO2 are separated by the steam-water separator at the outlet of the anode plate, CO2 is discharged through the carbon dioxide delivery pipeline; the unreacted carbon monoxide is discharged from the outlet of the cathode plate of the molten carbonate fuel cell and delivered to the anode of the solid oxide fuel cell through the carbon monoxide delivery pipeline.

[0013] The carbon deposit treatment method of the above-mentioned solar-based medium-temperature fuel cell carbon cycle power generation device is as follows: the controller monitors the voltage signal at both ends of the solid oxide fuel cell in real time. If the voltage signal is less than a fixed value, the controller controls the electronically controlled valve to open, and adds carbon dioxide to the anode of the solid oxide fuel cell to eliminate the carbon deposits at the anode; when the carbon deposits are eliminated, the voltage signal at both ends of the solid oxide fuel cell returns to the set value, and the controller controls the electronically controlled valve to close, cutting off the supply of carbon dioxide to the anode of the solid oxide fuel cell, and continuing to introduce carbon monoxide fuel to the anode of the solid oxide fuel cell.

[0014] The carbon deposition treatment method of the above-mentioned medium-temperature fuel cell carbon cycle power generation device based on solar energy is specifically controlled by a fuzzy control method:

[0015] The control structure of the fuzzy controller is a 2-input, 1-output structure:

[0016] Input variable x1: the difference between the positive and negative voltages of the solid oxide fuel cell and the standard transformer voltage;

[0017] Input variable x2: the transformation rate of the difference;

[0018] Output variable u1: opening time of the electronically controlled valve;

[0019] Input and output variable domain

[0020] The basic domain of input variables x1 and x2 is designed to be (0, 1), and then the two input quantities are divided into three linguistic variables, namely positive big (PB), zero (ZE), and negative big (NB). The membership function of the three linguistic variables of the two input variables in the basic domain (0, 1) is a triangular and trapezoidal combination membership function;

[0021] The basic domain of the output variable u1 is (0, 1), and the output variable is divided into 3 language variables U, namely positive big (PB), zero (ZE), and negative big (NB);

[0022] The membership function of the output variable u1 in the basic domain (0, 1) is a combined membership function of triangle and trapezoid;

[0023] Design of fuzzy control rules:

[0024] The principle of designing fuzzy control rules is that when the error is large or relatively large, the control amount is selected to eliminate the error as quickly as possible, and when the error is small or relatively small, the control amount is selected to control the overshoot. The fuzzy control rules for typical working conditions are:

[0025] Rule 1: If x1=PB, x2=PB, then u1=PB;

[0026] Rule 2: If x1=PB, x2=ZE, then u1=ZE;

[0027] Rule 3: If x1=PB, x2=NB, then u1=NB;

[0028] Rule 4: If x1=ZE, x2=PB, then u1=ZE;

[0029] Rule 5: If x1=ZE, x2=ZE, then u1=ZE;

[0030] Rule 6: If x1=ZE, x2=NB, then u1=NB;

[0031] Rule 7: If x1=NB, x2=PB, then u1=NB;

[0032] Rule 8: If x1=NB, x2=ZE, then u1=NB;

[0033] Rule 9: If x1=NB, x2=NB, then u1=NB;

[0034] Defuzzification process:

[0035] The maximum membership method is used for defuzzification.

[0036] The working principle of the medium-temperature fuel cell carbon cycle power generation device based on solar energy of the present invention: In the device of the present invention, the molten carbonate fuel cell, the solid oxide fuel cell, and the carbon reaction chamber all need to operate at high temperature, and the operating temperature is about 700 degrees (the specific operating temperature depends on the materials used in each link). The required high temperature comes from solar energy. The solar energy is focused to the solar collector through the solar reflector group, and the heat energy is stored in the heat storage through the solar heat exchanger. The heat storage provides heat energy to the molten carbonate fuel cell through the separation heat exchanger, provides heat energy to the solid oxide fuel cell through the fuel cell stack heat exchanger, and provides heat energy to the carbon reaction chamber through the carbon reaction chamber heat exchanger. A large amount of solid carbon is placed in the carbon reaction chamber, and carbon dioxide is introduced into it to convert the solid carbon into gaseous carbon monoxide. The carbon dioxide that does not participate in the reaction and the generated carbon monoxide form a mixed gas at the outlet. The mixed gas passes through the mixed gas separation device, and the carbon monoxide / carbon dioxide mixed gas enters from the cathode plate inlet of the molten carbonate fuel cell. The carbon dioxide in the mixed gas reacts with oxygen at the cathode of the molten carbonate fuel cell to generate CO3 2- ions, and the unreacted carbon monoxide in the mixed gas is discharged from the cathode plate outlet of the molten carbonate fuel cell and sent to the solid oxide fuel cell through the carbon monoxide delivery pipeline; CO3 2- The ions pass through the electrolyte layer and react with H2 at the anode to generate H2O and CO2. After H2O and CO2 are separated by the steam-water separator at the outlet of the anode plate of the molten carbonate fuel cell, CO2 is discharged through the carbon dioxide delivery pipeline; the carbon dioxide is returned to the carbon reaction chamber to participate in the circulation reaction; carbon monoxide, as the fuel of the solid oxide fuel cell, is prone to carbon deposition at the anode. The present invention determines whether carbon deposition is generated at the anode by detecting the voltage at both ends of the solid oxide fuel cell. If carbon deposition is generated, the voltage at both ends of the solid oxide fuel cell will drop significantly. At this time, the controller controls the carbon dioxide electric control valve to open, and the carbon dioxide gas discharged from the mixed gas separation device is sent to the anode of the solid oxide fuel cell to eliminate the carbon deposition. When the voltage at both ends of the solid oxide fuel cell is restored, the controller controls the carbon dioxide electric control valve to close, and stops the supply of carbon dioxide to the solid oxide fuel cell.

[0037] Beneficial effects: First, the present invention utilizes solar energy as the heat energy source required by the system, and does not require other power sources, which has the advantages of energy saving and environmental protection; secondly, the present invention gasifies solid carbon, uses the obtained carbon monoxide as fuel for the solid oxide fuel cell, and returns the exhaust carbon dioxide of the solid oxide fuel cell to the carbon gasification chamber again, so that the entire power generation process forms a closed loop, without the need to discharge any gas and substance to the outside, effectively avoiding the problem of environmental pollution; thirdly, the present invention utilizes molten carbonate fuel cells to effectively separate the mixed gas of carbon monoxide and carbon dioxide; finally, the present invention utilizes carbon dioxide to eliminate carbon deposits on the anode of the solid oxide fuel cell, which can ensure the long-term and stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a system principle diagram of the medium-temperature fuel cell carbon cycle power generation device based on solar energy of the present invention;

[0039] Figure 2 This is a schematic diagram of the gas separation principle of a molten carbonate fuel cell;

[0040] Figure 3 Schematic diagram of the structure of a molten carbonate fuel cell. DETAILED DESCRIPTION

[0041] like Figures 1 to 3As shown, the medium-temperature fuel cell carbon cycle power generation device based on solar energy of the present invention comprises a solar reflector group 1, a solar collector 2, a solar heat exchanger 3, a heat storage device 4, a separation heat exchanger 5, a mixed gas separation device 6, an electric control valve 7, a solid oxide fuel cell 8, a controller 9, an inverter 10, a fuel cell stack heat exchanger 11, a carbon reaction chamber 12 and a carbon reaction chamber heat exchanger 13; the solar reflector group 1 reflects the sunlight and focuses it on the solar collector 2, the working medium in the solar collector 2 is heated to a high temperature, and the working medium in the solar collector 2 transfers the heat to the heat through the solar heat exchanger 3. The carbon monoxide generated by the carbon reaction chamber 12 is discharged into the mixed gas separation device 6 together with the carbon dioxide mixed gas that has not participated in the reaction through the gas discharge port. After the mixed gas is separated by the mixed gas separation device 6, the carbon monoxide is sent to the solid oxide fuel cell 8. The solid oxide fuel cell 8 is used as fuel (the separated carbon monoxide is sent to the carbon monoxide storage tank 15 through the carbon monoxide delivery pipeline, and the carbon monoxide in the storage tank 15 is sent to the anode gas inlet of the solid oxide fuel cell 8 through the gas pipe, and the gas pipe is provided with an electric control valve 16). The solid oxide fuel cell 8 generates carbon dioxide and electric energy after the reaction. The electric energy is converted into AC electric energy through the inverter 10 to supply the load. The carbon dioxide generated by the solid oxide fuel cell 8 is fed back to the carbon reaction chamber 12 for continuing to convert the solid carbon into carbon monoxide; at the same time, the carbon dioxide separated by the mixed gas separation device 6 is passed through the The carbon dioxide is discharged through the carbon dioxide delivery pipeline, which is divided into two branches, branch I is connected to the carbon reaction chamber 12, and branch II is connected to the anode of the solid oxide fuel cell 8. The branch II is provided with an electric control valve 7; when carbon dioxide is needed, the electric control valve 7 is opened to deliver carbon dioxide to the anode gas inlet of the solid oxide fuel cell 8 (at this time, the electric control valve 16 is in a closed state) to remove the carbon deposits generated by the anode. The controller 9 detects the voltage at both ends of the solid oxide fuel cell 8 in real time, determines the carbon deposit situation, and controls the actions of the electric control valve 7 and the electric control valve 16 according to the carbon deposit situation. The electric control valve 7 and the electric control valve 16 are respectively connected to the controller 9 through cables, and the acquisition module 17 acquires the voltage at both ends of the solid oxide fuel cell 8 in real time, and sends the acquired signal to the controller 9 (the acquisition module 17 is a voltage sensor), that is, the cathode and anode of the solid oxide fuel cell are respectively connected to the voltage sensor 17, and the voltage sensor 17 is connected to the controller 9 through cables.

[0042] The mixed gas separation device 6 includes a molten carbonate fuel cell 16 and a water-gas separator 14 located at the gas outlet of the anode plate of the molten carbonate fuel cell 16; the molten carbonate fuel cell 16 is connected in parallel with the solid oxide fuel cell 8 to supply power to the external load, that is, the cathode of the molten carbonate fuel cell 16 is connected in parallel with the negative electrode of the solid oxide fuel cell 8 through a wire, and the anode of the molten carbonate fuel cell 16 is connected in parallel with the positive electrode of the solid oxide fuel cell 8 through a wire. The water-gas separator 14 is used to separate CO2, H2O and unreacted H2, and the unreacted H2 is returned to the anode of the molten carbonate fuel cell through the gas path and the anode plate inlet for reuse.

[0043] The molten carbonate fuel cell 16 of the present invention is a fuel cell composed of a porous lithium nickel oxide cathode 6-1, a porous electrolyte membrane 6-2, a porous metal anode 6-3 and a metal plate, and its electrolyte is a molten carbonate. The metal plates are respectively an anode plate 18 and a cathode plate 21, and the anode plate 18 is provided with an anode air inlet 20 and an anode air outlet 19, and the cathode plate 21 is provided with a cathode air inlet 23 and a cathode air outlet 22. A perforated current collector 25 is also provided between the cathode 6-1 and the cathode plate 21, and between the anode 6-3 and the anode plate 18.

[0044] A gas flow channel 24 is provided on the side of the cathode plate 21 that contacts the cathode 6-1. When the mixed gas flows in from the air inlet 23 of the cathode plate 21, the gas in the mixed gas that can react on the cathode surface gradually reacts with the cathode surface through the air channel, and the generated product enters the anode through the electrolyte layer 6-2. The cathode 6-1 and the anode 6-3 themselves are porous materials. The mixed gas enters from the air inlet 23 of the cathode plate 21. After a very long air channel reaction, the gas discharged from the air outlet 22 of the cathode plate 21 can be considered as the gas discharged from the outlet as all the gases that did not participate in the reaction.

[0045] The anode 6-3 of the molten carbonate fuel cell 16 is nickel; the cathode 6-1 is lithium nickel oxide; the electrolyte layer 6-2 is a mixture of carbonate Li2CO3 and K2CO3 (the electrolyte layer 6-2 conducts CO3 2- ions); wherein the mass percentage of Li2CO3 is 62%, and the mass percentage of K2CO3 is 38%.

[0046] The exhaust port of the carbon reaction chamber 12 is connected to the air inlet 23 of the cathode plate 21 of the molten carbonate fuel cell 16, and the cathode plate air inlet 23 is also connected to the external oxygen tank through a branch pipe. The carbon dioxide in the mixed gas reacts with oxygen at the cathode 6-1 of the molten carbonate fuel cell 16 to generate CO3 2- Ions, CO3 2-The ions pass through the electrolyte layer 6-2 and react with H2 at the anode 6-3 to generate H2O and CO2. After H2O and CO2 are separated by the steam-water separator 14 at the anode plate outlet 19, CO2 is discharged through the carbon dioxide delivery pipeline; the unreacted carbon monoxide in the mixed gas is discharged from the cathode plate outlet 22 of the molten carbonate fuel cell 16 and delivered to the solid oxide fuel cell 8 through the carbon monoxide delivery pipeline.

[0047] The thermal energy of the device of the present invention comes from the thermal utilization of solar energy. The generation and transmission of thermal energy are specifically as follows: the solar reflector group 1 reflects the sunlight and focuses it on the solar thermal collector 2. The working fluid in the solar thermal collector 2 is heated to a high temperature of more than 900 degrees. The working fluid in the solar thermal collector 2 stores the thermal energy in the heat reservoir 4 through the solar heat exchanger 3. The temperature of the heat reservoir 4 is greater than 800 degrees. The heat reservoir 4 provides thermal energy to the mixed gas separation device 6 through the separation heat exchanger 5. The operating temperature of the mixed gas separation device 6 is 750 degrees; the heat reservoir 4 provides thermal energy to the solid oxide fuel cell 8 through the fuel cell stack heat exchanger 11. The operating temperature of the solid oxide fuel cell 8 is 750 degrees; the heat reservoir 4 provides thermal energy to the carbon reaction chamber 12 through the carbon reaction chamber heat exchanger 13. The operating temperature of the carbon reaction chamber 12 is 700 degrees.

[0048] The present invention is based on the carbon deposition treatment method of the medium-temperature fuel cell carbon cycle power generation device of solar energy. The controller uses the fuzzy control method to control the opening and closing of the electric control valve 7:

[0049] The controller 9 monitors the voltage signal at both ends of the solid oxide fuel cell 8 in real time. If the voltage signal is less than a fixed value, the controller 9 controls the electronically controlled valve 7 to open and closes the electronically controlled valve 16. At this time, carbon dioxide is added to the anode of the solid oxide fuel cell 8 to eliminate carbon deposits on the anode. When the carbon deposits are eliminated, the voltage signal at both ends of the solid oxide fuel cell 8 returns to the set value. The controller 9 controls the electronically controlled valve 7 to close, cuts off the supply of carbon dioxide to the anode, and opens the electronically controlled valve 16 to continue to supply fuel carbon monoxide to the anode.

[0050] The fuzzy control method is as follows:

[0051] The control structure of the fuzzy controller is a 2-input, 1-output structure:

[0052] Input variable x1: the difference between the positive and negative voltages of the solid oxide fuel cell 8 and the standard voltage transformation;

[0053] Input variable x2: the transformation rate of the difference;

[0054] Output variable u1: opening time of the electric control valve 7;

[0055] Input and output variable domain

[0056] The basic domain of input variables x1 and x2 is designed to be (0, 1), and then the two input quantities are divided into three linguistic variables, namely positive big (PB), zero (ZE), and negative big (NB). The membership function of the three linguistic variables of the two input variables in the basic domain (0, 1) is a triangular and trapezoidal combination membership function;

[0057] The basic domain of the output variable u1 is (0, 1), and the output variable is divided into 3 language variables U, namely positive big (PB), zero (ZE), and negative big (NB);

[0058] The membership function of the output variable u1 in the basic domain (0, 1) is a combined membership function of triangle and trapezoid;

[0059] Design of fuzzy control rules:

[0060] The principle of designing fuzzy control rules is that when the error is large or relatively large, the control amount is selected to eliminate the error as quickly as possible, and when the error is small or relatively small, the control amount is selected to control the overshoot. The fuzzy control rules for typical working conditions are:

[0061] Rule 1: If x1=PB, x2=PB, then u1=PB;

[0062] Rule 2: If x1=PB, x2=ZE, then u1=ZE;

[0063] Rule 3: If x1=PB, x2=NB, then u1=NB;

[0064] Rule 4: If x1=ZE, x2=PB, then u1=ZE;

[0065] Rule 5: If x1=ZE, x2=ZE, then u1=ZE;

[0066] Rule 6: If x1=ZE, x2=NB, then u1=NB;

[0067] Rule 7: If x1=NB, x2=PB, then u1=NB;

[0068] Rule 8: If x1=NB, x2=ZE, then u1=NB;

[0069] Rule 9: If x1=NB, x2=NB, then u1=NB;

[0070] Defuzzification process:

[0071] The maximum membership method is used for defuzzification.

Claims

1. A medium-temperature fuel cell carbon cycle power generation device based on solar energy, characterized in that: It includes a solar energy absorption and conversion device, a carbon reaction chamber, a mixed gas separation device and a solid oxide fuel cell; the solar energy absorption and conversion device supplies heat energy to the carbon reaction chamber, the mixed gas separation device and the solid oxide fuel cell through a heat exchanger respectively; the carbon reaction chamber generates carbon monoxide by using heat energy after being filled with carbon dioxide, the exhaust port of the carbon reaction chamber is connected to the mixed gas separation device, the mixed gas separation device separates the carbon monoxide and carbon dioxide discharged from the carbon reaction chamber, the separated carbon monoxide is sent to the solid oxide fuel cell through a carbon monoxide delivery pipeline, the separated carbon monoxide is sent to a carbon monoxide storage tank through a carbon monoxide delivery pipeline, the carbon monoxide in the carbon monoxide storage tank is sent to the anode gas inlet of the solid oxide fuel cell through a gas pipe, and an electric control valve II is provided on the gas pipe; the separated carbon dioxide is discharged through a carbon dioxide delivery pipeline, the carbon dioxide delivery pipeline is divided into two branches, branch I is connected to the carbon reaction chamber, branch II is connected to the anode of the solid oxide fuel cell, and branch II is provided with an electric control valve I; the solid oxide fuel cell generates carbon dioxide and electric energy by using carbon monoxide, and the generated Carbon dioxide is sent into the carbon reaction chamber, and the generated electric energy is supplied to the external load; it also includes a controller, and the electric control valve I and the electric control valve II are connected to the controller through cables respectively. The controller collects the voltage at both ends of the solid oxide fuel cell through a voltage sensor, judges the carbon deposition situation, and controls the actions of the electric control valve I and the electric control valve II according to the carbon deposition situation; the mixed gas separation device includes a molten carbonate fuel cell and a steam-water separator located at the gas outlet of the anode plate of the molten carbonate fuel cell; wherein the molten carbonate fuel cell and the solid oxide fuel cell are connected in parallel to supply power to the external load; the anode of the molten carbonate fuel cell is metal nickel; the cathode is lithium nickel oxide; the electrolyte layer is a mixture of carbonate Li2CO3 and K2CO3; wherein the mass percentage of Li2CO3 is 62%, and the mass percentage of K2CO3 is 38%; the exhaust port of the carbon reaction chamber is connected to the cathode plate air inlet of the molten carbonate fuel cell, and the cathode plate air inlet is also connected to the external oxygen tank through a branch pipe, and the carbon dioxide reacts with oxygen at the cathode of the molten carbonate fuel cell to generate CO3 2- Ions, CO3 2- The ions pass through the electrolyte layer and react with H2 at the anode to generate H2O and CO2. After H2O and CO2 are separated by the steam-water separator at the gas outlet of the anode plate, CO2 is discharged through the carbon dioxide delivery pipeline; the unreacted carbon monoxide is discharged from the gas outlet of the cathode plate of the molten carbonate fuel cell and delivered to the anode of the solid oxide fuel cell through the carbon monoxide delivery pipeline; The carbon deposit treatment method of the above-mentioned power generation device is specifically as follows: the controller monitors the voltage signal at both ends of the solid oxide fuel cell in real time. If the voltage signal is less than a fixed value, the controller controls the electronically controlled valve I to open, and carbon dioxide is added to the anode of the solid oxide fuel cell to eliminate the carbon deposits at the anode; when the carbon deposits are eliminated, the voltage signal at both ends of the solid oxide fuel cell returns to the set value, and the controller controls the electronically controlled valve I to close, cutting off the supply of carbon dioxide to the anode of the solid oxide fuel cell, and continuing to introduce carbon monoxide fuel to the anode of the solid oxide fuel cell through the electronically controlled valve II; The controller uses fuzzy control method to control the electric control valve I: The control structure of the fuzzy controller is a 2-input, 1-output structure: Input variable x1: the difference between the positive and negative voltages of the solid oxide fuel cell and the standard transformer voltage; Input variable x2: the transformation rate of the difference; Output variable u1: opening time of the electronically controlled valve; Input and output variable domain The basic domain of input variables x1 and x2 is designed to be (0,1), and then the two input quantities are divided into three linguistic variables, namely positive big (PB), zero (ZE), and negative big (NB). The membership function of the three linguistic variables of the two input variables in the basic domain (0,1) is a combined membership function of triangle and trapezoid; The basic domain of the output variable u1 is (0, 1), and the output variable is divided into 3 language variables U, namely positive big (PB), zero (ZE), and negative big (NB); The membership function of the output variable u1 in the basic domain (0, 1) is a combined membership function of triangle and trapezoid; Design of fuzzy control rules: The principle of designing fuzzy control rules is that when the error is large or relatively large, the control amount is selected to eliminate the error as quickly as possible, and when the error is small or relatively small, the control amount is selected to control the overshoot. The fuzzy control rules for typical working conditions are: Rule 1: If x1=PB, x2=PB, then u1=PB; Rule 2: If x1=PB, x2=ZE, then u1=ZE; Rule 3: If x1=PB, x2=NB, then u1=NB; Rule 4: If x1=ZE, x2=PB, then u1=ZE; Rule 5: If x1=ZE, x2=ZE, then u1=ZE; Rule 6: If x1=ZE, x2=NB, then u1=NB; Rule 7: If x1=NB, x2=PB, then u1=NB; Rule 8: If x1=NB, x2=ZE, then u1=NB; Rule 9: If x1=NB, x2=NB, then u1=NB; Defuzzification process: The maximum membership method is used for defuzzification.

2. The medium-temperature fuel cell carbon cycle power generation device based on solar energy according to claim 1 is characterized in that: The solar energy absorption and conversion device includes a solar reflector group, a solar collector, a solar heat exchanger and a heat storage device. The solar reflector group reflects the sunlight and focuses it on the solar collector. The heat energy in the solar collector is stored in the heat storage device through the solar heat exchanger.

3. The medium-temperature fuel cell carbon cycle power generation device based on solar energy according to claim 2 is characterized in that: The heat exchanger includes a separation heat exchanger, a fuel cell stack heat exchanger and a carbon reaction chamber heat exchanger. The heat energy output end of the heat storage is connected to the heat energy input ends of the separation heat exchanger, the fuel cell stack heat exchanger and the carbon reaction chamber heat exchanger respectively. The heat energy output end of the separation heat exchanger is connected to the mixed gas separation device, the heat energy output end of the fuel cell stack heat exchanger is connected to the solid oxide fuel cell, and the heat energy output end of the carbon reaction chamber heat exchanger is connected to the carbon reaction chamber.

4. The medium-temperature fuel cell carbon cycle power generation device based on solar energy according to claim 1 is characterized in that: The carbon reaction chamber contains solid coal, and the filling amount of the coal is more than 3 / 4 of the volume of the cavity of the carbon reaction chamber.

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