Combustion device and combustion method for SOFC (solid oxide fuel cell) power generation system taking carbon-based synthesis gas as fuel

Abstract

The invention relates to a combustion device and a combustion method for an SOFC (solid oxide fuel cell) power generation system taking carbon-based synthesis gas as fuel, and the combustion device disclosed by the invention can be used as a starting combustor and can improve the net power generation efficiency of the SOFC power generation system. Moreover, the combustion device disclosed by the invention utilizes the cathode tail gas at the starting temperature rise stage as the combustion-supporting gas to replace external air input, so that the device cost can be reduced while the economic effect of the system is improved. Meanwhile, according to the combustion device disclosed by the invention, the cathode tail gas entering the cathode tail gas cavity from the cathode tail gas branch to diffuse and flow can be used as cooling gas of the head of the combustor, so that the temperature of the head of the combustor is adjusted, and local overtemperature is prevented. Besides, the combustion device disclosed by the invention can be used for combusting the anode tail gas and the cathode tail gas of the SOFC power generation system after being mixed, so that unreacted fuel in the anode tail gas can be completely combusted, near-zero emission of CO2 is achieved, and the fuel utilization rate of the system and the overall efficiency of the system can be further improved.

Description

Technical Field

[0001] The present disclosure relates to the field of solid oxide fuel cells, and in particular, to a combustion device and a combustion method for a SOFC power generation system using carbon-based synthesis gas as fuel. Background Art

[0002] Solid Oxide Fuel Cell (SOFC) is an electrochemical power generation device that directly converts the chemical energy of fuel into electrical energy. Compared with traditional coal-fired power generation technology, SOFC power generation has high energy conversion rate, low energy loss, and low carbon emissions. Compared with PEMFC, which is also a third-generation fuel cell, SOFC does not use precious metal catalysts and has a wide fuel adaptability. It uses natural gas, synthesis gas, biomass gas (such as biogas), etc. as raw materials. It can also use coal gas, coalbed methane, shale gas, industrial by-product gas, etc. as raw materials, which promotes the conversion efficiency of traditional fossil energy, reduces CO2 emissions, and realizes the clean and efficient use of fossil energy. In addition, the waste heat temperature of the SOFC power generation system is high, which can generate a large amount of low-grade heat source.

[0003] Existing SOFC power generation systems typically operate in high-temperature environments. During the SOFC system startup phase, an electric heater heats the cathode air, gradually heating the stack and system to the SOFC operating temperature. To achieve this operating state, the SOFC power generation system typically includes a stack module and auxiliary equipment such as a blower, electric heater, heat exchanger, and exhaust burner. However, SOFC power generation systems are limited by system cost and integration. High-power, large-volume electric heaters are not suitable for use in SOFC systems, and the heater's heating rate also significantly limits the SOFC startup time, making it difficult to build SOFC systems with tens or hundreds of thousands of kilowatts of power. Furthermore, existing combustion devices use external air as cooling gas, requiring the addition of a blower and corresponding pipelines, which increases the blower's electricity consumption and layout space, thereby reducing economic benefits and costs. Furthermore, existing SOFC power generation systems typically discharge the anode exhaust directly, resulting in low fuel utilization and overall efficiency. Summary of the Invention

[0004] The purpose of the present disclosure is to provide a combustion device and a combustion method for a SOFC power generation system using carbon-based synthesis gas as fuel, so as to solve the problems existing in the prior art of low net power generation efficiency, large footprint, high economic benefits and costs, low fuel utilization and overall system efficiency.

[0005] 19. The vent gas distribution system of claim 18, wherein the vent gas distribution system comprises a combustion chamber, a tail gas treatment chamber, and an ion igniter; the combustion chamber is coaxially arranged with the tail gas treatment chamber, and the tail gas treatment chamber is arranged at the top of the combustion chamber; the tail gas treatment chamber comprises a coaxially arranged ignition fuel gas chamber, a cathode tail gas chamber, an inner chamber, and a tail gas mixing chamber; the ignition fuel gas chamber, the inner chamber, the tail gas mixing chamber, and the cathode tail gas chamber are arranged in sequence from the inside to the outside; a sealing baffle is provided in the inner chamber, and the sealing baffle divides the inner chamber into an anode tail gas chamber and a combustion-supporting air chamber; an anode tail gas through-hole is provided on the inner wall of the tail gas mixing chamber, and the cathode tail gas chamber is connected to the tail gas mixing chamber through the cathode tail gas through-hole; a cathode tail gas through-hole is provided on the outer wall of the tail gas mixing chamber, and the anode tail gas chamber is connected to the The exhaust gas mixing chamber is connected; an ignition gas nozzle is provided at the bottom of the ignition gas chamber, and the ignition gas chamber is connected to the combustion chamber through the ignition gas nozzle; an ignition gas pipeline is provided on the side wall of the ignition gas chamber for connecting to the ignition gas source; a combustion-supporting air nozzle is provided at the bottom of the combustion-supporting air chamber, and the combustion-supporting air chamber is connected to the combustion chamber through the combustion-supporting air nozzle; a mixed gas nozzle is provided at the bottom of the exhaust gas mixing chamber, and the exhaust gas mixing chamber is connected to the combustion chamber through the mixed gas nozzle; the combustion-supporting air chamber is connected to one end of the cathode exhaust pipeline through the combustion-supporting air pipeline, and the other end of the cathode exhaust pipeline is used to be connected to the cathode exhaust outlet of the SOFC power generation system; the cathode exhaust chamber is connected to the cathode exhaust pipeline through the cathode exhaust branch; the anode exhaust chamber is used to be connected to the anode exhaust outlet of the SOFC power generation system through the anode exhaust pipeline.

[0006] Optionally, the combustion device further includes a UV fire detector for detecting the ignition condition of the combustion device; the UV fire detector is arranged on the outer wall of the combustion chamber.

[0007] Optionally, the ion igniter is arranged inside the ignition gas chamber along the axial direction of the combustion device, and one end of the combustion device extends to the upper part of the combustion chamber.

[0008] Optionally, the combustion chamber and the exhaust gas treatment chamber are respectively cylindrical structures; a circular opening is provided at the top of the combustion chamber, and the area where the ignition gas nozzle, the combustion-supporting air nozzle and the mixed gas nozzle are provided at the bottom of the exhaust gas treatment chamber coincides with the circular opening; the combustion chamber also includes a flame stabilizer; the flame stabilizer includes a circular concave surface containing a flame guide hole and a flame guide assembly arranged on the back side of the circular concave surface; the concave surface of the flame stabilizer faces the bottom of the exhaust gas treatment chamber and the edge of the concave surface of the flame stabilizer is tightly combined with the top surface of the combustion chamber; the flame guide hole on the circular concave surface coincides with the flame guide hole on the flame guide assembly.

[0009] Optionally, flow regulating valves are respectively provided on the anode tail gas pipeline, the ignition fuel gas pipeline, the cathode tail gas branch and the combustion-supporting air pipeline to regulate the flow of materials in each pipeline.

[0010] The second aspect of the present disclosure provides a method for combustion using the combustion device described in the first aspect, the method comprising: S1, allowing the ignition gas to enter the ignition gas chamber through the ignition gas pipeline, allowing the cathode exhaust gas to enter the cathode exhaust pipeline, and then enter the combustion chamber through the combustion-supporting air pipeline and the combustion-supporting air chamber in turn, and mix with the ignition gas from the ignition gas chamber to obtain a mixed gas phase; igniting the mixed gas phase under the action of the ion igniter; S2, allowing part of the cathode exhaust gas in the cathode exhaust pipeline to enter the combustion chamber through the cathode exhaust branch, the cathode exhaust chamber, and the exhaust mixing chamber in turn to participate in combustion until the temperature of the SOFC power generation system is raised to the operating temperature, and then gradually reducing the flow rate of the ignition gas; S3, when the SOFC power generation system starts to generate power under load, stopping the addition of the ignition gas, and allowing the anode exhaust gas entering the anode exhaust chamber through the anode exhaust pipeline and the cathode exhaust gas in the cathode exhaust chamber to enter the exhaust mixing chamber to mix, and then enter the combustion chamber to participate in combustion.

[0011] Optionally, the ion igniter is used to ignite the mixed gas phase in the combustion chamber until a UV flame detector of the combustion device detects a flame, and then the ignition process is stopped.

[0012] Optionally, step S1 further includes, after allowing the cathode tail gas to enter the cathode tail gas pipeline, opening the flow regulating valve on the combustion air pipeline to allow the cathode tail gas to enter the combustion air chamber; opening the flow regulating valve on the ignition gas pipeline to allow the ignition gas to enter the ignition gas chamber.

[0013] Optionally, step S2 also includes opening the flow regulating valve on the cathode tail gas branch to allow part of the cathode tail gas to enter the cathode tail gas chamber; when the temperature of the SOFC power generation system rises to the operating temperature, gradually reducing the opening of the flow regulating valve on the ignition gas pipeline.

[0014] Optionally, step S3 further includes, when the SOFC power generation system starts to generate power under load, closing the flow regulating valve on the ignition gas pipeline; and opening the flow regulating valve on the anode tail gas pipeline to allow the anode tail gas to enter the anode tail gas chamber.

[0015] Through the above technical solution, the combustion device disclosed in the present invention can be used as a startup burner, avoiding the power consumption caused by the use of traditional electric heaters, and can improve the net power generation efficiency of the SOFC power generation system. In addition, the combustion device disclosed in the present invention uses the cathode exhaust gas in the startup temperature rise stage as a combustion-supporting gas instead of external air input, which not only saves the power consumption of the fan, but also saves the layout space of the SOFC power generation system, thereby reducing the cost of the device while improving the economic benefits of the system. At the same time, the combustion device disclosed in the present invention can make the cathode exhaust gas branch enter the cathode exhaust cavity and diffuse and flow, and can be used as a cooling gas for the burner head to regulate the temperature of the burner head and prevent local overheating. In addition, the combustion device disclosed in the present invention can make the anode and cathode exhaust gases of the SOFC power generation system be mixed and then burned, which can not only completely burn the unreacted fuel in the anode exhaust gas and achieve near-zero CO2 emissions, but also improve the fuel utilization rate of the system and the overall efficiency of the system.

[0016] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0018] Figure 1 The figure is a schematic diagram of a combustion device for a SOFC power generation system using carbon-based synthesis gas as fuel according to the present invention.

[0019] Figure 2 It is a cross-sectional schematic diagram of a combustion device disclosed in the present invention for a SOFC power generation system using carbon-based synthesis gas as fuel.

[0020] Figure 3 The present invention is a schematic diagram of a tail gas treatment chamber of a combustion device for a SOFC power generation system using carbon-based synthesis gas as fuel.

[0021] Figure 4Schematic diagram of a flame stabilizer 3 of a combustion device for a SOFC power generation system using carbon-based synthesis gas as fuel according to the present disclosure.

[0022] Description of Reference Numerals

[0023] 1. Combustion chamber; 2. UV flame detector; 3. Flame stabilizer; 4. Cathode exhaust chamber; 5. Anode exhaust chamber; 6. Exhaust gas mixing chamber; 7. Combustion air chamber; 8. Ignition gas chamber; 9. Ion igniter; 10. Anode exhaust pipeline; 11. Ignition gas pipeline; 12. Cathode exhaust pipeline; 13. Cathode exhaust branch; 14. Combustion air pipeline; 15. Ignition gas nozzle; 16. Combustion air nozzle; 17. Mixing gas nozzle. DETAILED DESCRIPTION

[0024] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0025] In this disclosure, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower positions of the device in normal use. Figure 1 In the drawing orientation, "inside" and "outside" refer to the outline of the device. In addition, the terms "first, second, and third" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first, second, and third" may explicitly or implicitly include one or more of such features. In the description of this disclosure, "plurality" means two or more, unless otherwise explicitly and specifically defined.

[0026] like Figure 1 、 Figure 2 and Figure 3As shown, the first aspect of the present disclosure provides a combustion device for a SOFC power generation system using carbon-based synthesis gas as fuel, the combustion device comprising a combustion chamber 1, an exhaust gas treatment chamber and an ion igniter 9; the combustion chamber 1 is coaxially arranged with the exhaust gas treatment chamber, and the exhaust gas treatment chamber is arranged on the top of the combustion chamber 1; the exhaust gas treatment chamber comprises a coaxially arranged ignition gas chamber 8, a cathode exhaust gas chamber 4, an inner chamber and an exhaust gas mixing chamber 6; the ignition gas chamber 8, the inner chamber, the exhaust gas mixing chamber The chamber 6 and the cathode tail gas chamber 4 are arranged in sequence from the inside to the outside; a sealing baffle is provided in the inner chamber, and the sealing baffle divides the inner chamber into an anode tail gas chamber 5 and a combustion air chamber 7; an anode tail gas through-hole is provided on the inner wall of the tail gas mixing chamber 6, and the cathode tail gas chamber 4 is connected to the tail gas mixing chamber 6 through the cathode tail gas through-hole; a cathode tail gas through-hole is provided on the outer wall of the tail gas mixing chamber 6, and the anode tail gas chamber 5 is connected to the tail gas mixing chamber 6 through the anode tail gas through-hole; the point An ignition gas nozzle 15 is provided at the bottom of the ignition gas chamber 8, and the ignition gas chamber 8 is connected to the combustion chamber 1 through the ignition gas nozzle 15; an ignition gas pipeline 11 is provided on the side wall of the ignition gas chamber 8 for connecting to the ignition gas source; a combustion air nozzle 16 is provided at the bottom of the combustion air chamber 7, and the combustion air chamber 7 is connected to the combustion chamber 1 through the combustion air nozzle 16; a mixed gas nozzle 17 is provided at the bottom of the exhaust gas mixing chamber 6, and the exhaust gas mixing chamber 6 is connected to the combustion chamber 1 through the mixed gas nozzle 17; the combustion air chamber 7 is connected to one end of the cathode exhaust pipeline 12 through the combustion air pipeline 14, and the other end of the cathode exhaust pipeline 12 is used to be connected to the cathode exhaust outlet of the SOFC power generation system; the cathode exhaust chamber 4 is connected to the cathode exhaust pipeline 12 through the cathode exhaust branch 13; the anode exhaust chamber 5 is used to be connected to the anode exhaust outlet of the SOFC power generation system through the anode exhaust pipeline 10.

[0027] Through the above technical solution, the combustion device disclosed in the present invention can be used as a startup burner, avoiding the power consumption caused by the use of traditional electric heaters, and can improve the net power generation efficiency of the SOFC power generation system. In addition, the combustion device disclosed in the present invention uses the cathode exhaust gas in the startup temperature rise stage as a combustion-supporting gas instead of external air input, which not only saves the power consumption of the fan, but also saves the layout space of the SOFC power generation system, thereby reducing the cost of the device while improving the economic benefits of the system. At the same time, the combustion device disclosed in the present invention can make the cathode exhaust gas branch enter the cathode exhaust cavity and diffuse and flow, and can be used as a cooling gas for the burner head to regulate the temperature of the burner head and prevent local overheating. In addition, the combustion device disclosed in the present invention can make the anode and cathode exhaust gases of the SOFC power generation system be mixed and then burned, which can not only completely burn the unreacted fuel in the anode exhaust gas and achieve near-zero CO2 emissions, but also improve the fuel utilization rate of the system and the overall efficiency of the system.

[0028] In one embodiment, Figure 1 As shown, the combustion chamber 1 described in the present disclosure is a cylindrical structure. The height and diameter of the internal cavity of the cylindrical structure can be flexibly set according to the specifications of the SOFC power generation system. In order to further improve the combustion effect of the battery exhaust and / or ignition gas in the combustion chamber 1, the ratio of the diameter and height of the cylindrical structure is preferably (0.5~0.8):1.

[0029] In one embodiment, a circular opening is provided at the top of the combustion chamber 1 of the present disclosure for connecting to the exhaust gas treatment chamber. Preferably, the center of the circular opening coincides with the center of the top surface of the combustion chamber 1. The size of the circular opening can be set according to the size of the exhaust gas treatment chamber. Specifically, the ratio of the diameter of the circular opening to the top diameter of the combustion chamber 1 is preferably (0.4-0.6):1.

[0030] In one embodiment, a flame detector is provided at the bottom of the combustion chamber 1 of the present disclosure for detecting whether the gas in the combustion chamber 1 has been successfully ignited. When the flame detector detects a flame in the combustion chamber 1, it indicates that the ignition has been successful. The flame detector used in the present disclosure is conventional in the art and is not specifically required by this application. For example, the flame detector is a UV flame detector 2.

[0031] In a preferred embodiment, the UV flame detector is on the same horizontal line as the center of the flame.

[0032] In one embodiment, Figure 3As shown, the exhaust gas treatment chamber described in the present invention has an overall cylindrical structure. The height and diameter of the cylindrical structure can be flexibly set according to the specifications of the SOFC power generation system. In order to further improve the combustion effect in the combustion chamber 1, the ratio of the diameter and height of the cylindrical structure is preferably (0.5~0.8):1.

[0033] In one embodiment, the bottom surfaces of the ignition gas chamber 8, the inner chamber, the exhaust gas mixing chamber 6 and the cathode exhaust chamber 4 in the exhaust gas treatment chamber described in the present disclosure can be in the same plane, or, with the cathode exhaust chamber 4 as a reference, the bottom surface protrusion distance increases in the order of the exhaust gas mixing chamber 6, the inner chamber and the ignition gas chamber 8.

[0034] In one embodiment, the top surface of the combustion chamber 1 refers to the contact surface facing the exhaust gas treatment chamber, and the bottom surface of the combustion chamber 1 refers to the surface where the UV fire detector 2 is provided.

[0035] In one embodiment, the bottom of the exhaust gas treatment chamber is divided into a connection area and a nozzle area. The nozzle area is circular and is arranged at the center of the bottom of the exhaust gas treatment chamber.

[0036] In one embodiment, the nozzle area includes a plurality of ignition gas nozzles 15, a plurality of combustion air nozzles 16 and a plurality of mixed gas nozzles 17; wherein, a plurality of ignition gas nozzles 15 are evenly arranged along the circumference of the bottom surface of the ignition gas chamber 8, so that the ignition gas can enter the combustion chamber 1 through the ignition gas nozzles 15; a plurality of combustion air nozzles 16 are evenly arranged along the circumference of the bottom surface of the combustion air chamber 7 of the inner chamber, so that the cathode exhaust gas can enter the combustion chamber 1 through the combustion air nozzles 16; a plurality of mixed gas nozzles 17 are evenly arranged along the circumference of the bottom surface of the exhaust mixing chamber 6, so that the cathode mixed exhaust gas can enter the combustion chamber 1 through the mixed gas nozzles 17.

[0037] Among them, the ignition gas nozzle 15, the combustion air nozzle 16 and the mixed gas nozzle 17 are all circular through holes; the aperture of the circular through hole can be set according to actual needs. In order to further improve the combustion effect, the aperture of the circular through hole can be preferably set to 3-10 mm.

[0038] In a preferred embodiment, the nozzle area of ​​the exhaust gas treatment chamber coincides with the circular opening provided at the top of the combustion chamber 1, so that the gas phase in the exhaust gas treatment chamber can enter the combustion chamber 1 for mixed combustion. The connection area of ​​the exhaust gas treatment chamber is connected to the upper surface of the top of the combustion chamber 1, so that the exhaust gas treatment chamber is connected above the combustion chamber 1.

[0039] In one embodiment, the heights of the ignition gas chamber 8, the inner chamber, the tail gas mixing chamber 6 and the cathode tail gas chamber 4 can be flexibly set according to the specifications of the SOFC power generation system, and this application does not make special requirements.

[0040] In one embodiment, the ratio of the heights of the ignition gas chamber 8 , the inner chamber, the tail gas mixing chamber 6 , and the cathode tail gas chamber 4 is (1.2-1.5):1:1:1.

[0041] In one embodiment, in order to improve the mixing effect of the anode tail gas and the cathode tail gas, the ratio of the height of the anode tail gas chamber 5 to the height of the inner chamber is (0.6-0.8):1.

[0042] In one embodiment, the tail gas treatment chamber disclosed herein further includes an anode tail gas pipeline 10 , an ignition fuel gas pipeline 11 , a cathode tail gas pipeline 12 , a cathode tail gas branch 13 and a combustion air pipeline 14 .

[0043] Among them, an anode tail gas inlet is provided on the top surface of the anode tail gas chamber 5, and the anode tail gas inlet is connected to the outlet of the anode tail gas pipeline 10. The inlet of the anode tail gas pipeline 10 is used to be connected to the anode tail gas outlet of the SOFC power generation system, so that the anode tail gas in the SOFC power generation system can enter the anode tail gas chamber 5 through the anode tail gas pipeline 10.

[0044] Among them, an ignition gas inlet is opened on the top surface or side wall of the ignition gas chamber 8, and the ignition gas inlet is connected to the outlet of the ignition gas pipeline 11. The inlet of the ignition gas pipeline 11 is used to be connected to the ignition gas source so that the ignition gas can enter the ignition gas chamber 8 through the ignition gas pipeline 11.

[0045] Among them, a cathode tail gas inlet is opened on the side wall of the cathode tail gas chamber 4, and the cathode tail gas inlet is connected to the outlet of the cathode tail gas branch 13, so that the cathode tail gas can enter the cathode tail gas chamber 4; a combustion air inlet is opened on the side wall of the combustion air chamber 7, and the combustion air inlet is connected to the outlet of the combustion air pipeline 14, so that the cathode tail gas can enter the combustion air chamber 7.

[0046] In one embodiment, a first flow regulating valve is provided on the anode tail gas pipeline 10, a second flow regulating valve is provided on the ignition gas pipeline 11, a third flow regulating valve is provided on the cathode tail gas branch 13, and a fourth flow regulating valve is provided on the combustion air pipeline 14. In this embodiment, by adjusting the opening of each flow regulating valve, the flow rate of the material in each pipeline can be adjusted, so that the combustion device of the present disclosure can be used under various operating conditions of the SOFC power generation system.

[0047] In a specific embodiment, when the SOFC power generation system begins to start up, the first and third flow control valves are closed, and the second and fourth flow control valves are opened to allow the ignition gas and cathode tail gas to mix and ignite. When the SOFC power generation system begins to heat up, the third flow control valve is opened to allow part of the cathode tail gas to serve as cooling gas to cool the combustion device. When the SOFC power generation system reaches operating temperature, the opening of the second flow control valve is gradually reduced to gradually reduce the flow rate of the ignition gas. When the SOFC power generation system begins to generate power under load, the second flow control valve is closed while the first flow control valve is opened to ensure that the mixed gas in the combustion chamber 1 is a mixture of cathode tail gas and anode tail gas.

[0048] In one embodiment, the ion igniter 9 is arranged inside the ignition gas chamber 8 along the axial direction of the combustion device, and one end of the combustion device extends to the upper part of the combustion chamber 1.

[0049] In one embodiment, the combustion chamber 1 further includes a flame stabilizer 3 , and the flame stabilizer 3 is tightly combined with the top surface of the combustion chamber 1 to form a flame stabilization cavity.

[0050] Among them, such as Figure 4 As shown, the flame stabilizer 3 includes a circular concave surface containing a flame guide hole and a flame guide assembly disposed on the back of the circular concave surface; the flame guide hole on the circular concave surface overlaps with the flame guide hole on the flame guide assembly, so that the flame stabilization cavity is connected to the combustion chamber 1. In this embodiment, the flame stabilizer 3 is placed in the combustion chamber, in front of the gas nozzle, and has a flame guide hole to stabilize the combustion flame, ensure that the flame is a thin and short flame, and ensure that the flame burns forward, can achieve ignition and flame stabilization under various gas flow rates, reduce combustion oscillation, avoid backfire, and improve combustion efficiency.

[0051] Among them, the concave surface of the flame stabilizer 3 faces the bottom of the exhaust gas treatment chamber and the edge of the concave surface of the flame stabilizer 3 is tightly combined with the top surface of the combustion chamber 1, so that the gas phase in the exhaust gas treatment chamber only enters the interior of the combustion chamber 1 through the flame stabilizer 3.

[0052] In one embodiment, a temperature measuring thermocouple may be inserted into the combustion chamber to monitor the internal temperature of the combustion chamber and the flame temperature.

[0053] A second aspect of the present disclosure provides a method for combustion using the combustion device according to the first aspect, the method comprising:

[0054] S1. The ignition gas enters the ignition gas chamber 8 through the ignition gas pipeline 11, the cathode exhaust gas enters the cathode exhaust pipeline 12, and then enters the combustion chamber 1 through the combustion air pipeline 14 and the combustion air chamber 7, where the gas is mixed with the ignition gas from the ignition gas chamber 8 to obtain a mixed gas phase; and the mixed gas phase is ignited by the ion igniter 9.

[0055] S2, allowing part of the cathode tail gas in the cathode tail gas pipeline 12 to enter the combustion chamber 1 through the cathode tail gas branch 13, the cathode tail gas chamber 4, and the tail gas mixing chamber 6 in sequence to participate in combustion until the temperature of the SOFC power generation system is raised to the operating temperature, and then reducing the flow rate of the ignition gas;

[0056] S3. When the SOFC power generation system starts to generate power under load, the addition of the ignition gas is stopped, and the anode tail gas entering the anode tail gas chamber 5 through the anode tail gas pipeline 10 and the cathode tail gas in the cathode tail gas chamber 4 are mixed into the tail gas mixing chamber 6 and then enter the combustion chamber 1 to participate in combustion.

[0057] Through the above-described method, when the SOFC power generation system is started, the present disclosure ignites the ignition gas and cathode exhaust gas in the combustion device, providing an initial heat source for the SOFC power generation system. This can replace the electric heater in traditional SOFC power generation systems, reducing the system's power consumption and thereby improving net power generation efficiency. Furthermore, the present disclosure utilizes unreacted cathode exhaust gas as combustion air to combust with the ignition gas to provide heat for the system. This method replaces external air input, eliminating the need for an external air supply blower and piping. This not only reduces the electricity consumption associated with the use of a blower, but also reduces the footprint of the SOFC power generation system, thereby lowering the system's economic benefits and equipment costs. Furthermore, by using a portion of the cathode exhaust gas as cooling gas for the burner head, the burner head temperature is regulated to prevent local overheating. Furthermore, by mixing the cathode exhaust gas and anode exhaust gas and then burning them, unreacted CO and H₂ in the anode exhaust gas can be completely burned, improving the system's fuel efficiency.

[0058] In one embodiment, step S1 further includes: opening the second flow regulating valve on the ignition gas pipeline 11, allowing the ignition gas to enter the ignition gas chamber 8 through the ignition gas pipeline 11, and allowing the ignition gas to enter the combustion chamber 1 through the ignition gas nozzle 15; opening the fourth flow regulating valve on the combustion air pipeline 14, allowing the cathode exhaust gas to enter the cathode exhaust gas pipeline 12, and then enter the combustion air chamber 7 through the combustion air pipeline 14, and allowing the cathode exhaust gas to enter the combustion chamber 1 through the combustion air nozzle 16; and mixing the ignition gas and the cathode exhaust gas entering the combustion chamber 1 to obtain a mixed gas phase. When the ion igniter 9 receives the ignition signal, the ion igniter 9 ignites the mixed gas phase in the combustion chamber 1 until the UV flame detector of the combustion device detects a flame, and then stops the ignition process.

[0059] In one embodiment, the ignition process includes: causing the ion igniter 9 to ignite the mixed gas phase in the combustion chamber 1 for 2 to 3 seconds. If the UV flame detector 2 detects a flame, it means that the ignition is successful; if the UV flame detector 2 does not detect a flame, the ignition process is repeated 3-5 times; if the UV flame detector 2 still does not detect a flame, the entire combustion device is replaced with protective gas and the ignition process is performed again until the UV flame detector of the combustion device detects a flame, and then the ignition process is stopped.

[0060] In one embodiment, the ignition fuel gas used in the present disclosure includes hydrogen and / or synthesis gas.

[0061] In this embodiment, during startup of the SOFC power generation system, the air introduced into the cathode does not participate in any reaction in the SOFC stack, and the oxygen content in the cathode exhaust gas is greater than 20%. This cathode exhaust gas is then introduced into the combustion air chamber as combustion-supporting air to ignite the burner. During the temperature rise phase, the amount of ignition gas is adjusted in real time based on the amount of ignition gas to ensure a stable combustion flame and a steady rate of temperature change in the burner during the temperature rise phase.

[0062] In one embodiment, step S2 also includes opening the third flow regulating valve on the cathode exhaust gas branch 13 to allow part of the cathode exhaust gas to enter the cathode exhaust gas chamber 4; allowing this part of the cathode exhaust gas to enter the exhaust gas mixing chamber 6 through the cathode exhaust gas through hole, and a small part of the cathode exhaust gas in the exhaust gas mixing chamber 6 to enter the anode exhaust gas chamber 5 through the anode exhaust gas through hole; allowing the cathode exhaust gas in the exhaust gas mixing chamber 6 to enter the combustion chamber 1 through the mixed gas nozzle 17 to participate in combustion, so that this part of the cathode exhaust gas can almost fill the entire exhaust treatment chamber, thereby cooling the combustion part of the combustion device.

[0063] In this embodiment, a portion of the cathode exhaust gas acts as cooling gas, flowing into the outer cathode exhaust chamber for diffusion and regulating the burner head temperature. A higher internal burner temperature increases the flame's propagation speed and makes flashback more likely. Regulating the burner head temperature effectively reduces the likelihood of flashback.

[0064] In one embodiment, step S2 further includes, when the temperature of the SOFC power generation system is raised to the operating temperature, gradually reducing the opening of the flow regulating valve on the ignition gas pipeline 11, so that the flow of the ignition gas entering the ignition gas chamber 8 gradually decreases.

[0065] In one embodiment, step S3 further includes, when the SOFC power generation system starts to generate electricity, closing the flow regulating valve on the ignition gas pipeline 11, and opening the flow regulating valve on the anode tail gas pipeline 10, so that the anode tail gas enters the anode tail gas chamber 5; allowing the anode tail gas inside the anode tail gas chamber 5 to enter the tail gas mixing chamber 6 through the anode tail gas through hole, and enter the combustion chamber 1 through the mixed gas nozzle 17 to participate in the reaction.

[0066] In this embodiment, the SOFC power generation system begins load generation some time after reaching operating temperature. The operating temperature of the SOFC power generation system is determined by the type of power generation system. For example, the operating temperature of the SOFC power generation system used in this disclosure is 700-750°C. When the SOFC power generation system begins generating electricity, the anode tail gas contains unreacted CO and H2 in addition to CO2 and water vapor. This anode tail gas is fed into a combustion device for combustion, converting the CO and H2 into carbon dioxide and water vapor, thereby improving the fuel utilization rate of the SOFC power generation system.

[0067] In one embodiment, in order to fully utilize the thermal energy and chemical energy of the high-temperature exhaust gas, the exhaust gas is passed into a combustion device and the flue gas after combustion is heat exchanged with the feed fuel of the SOFC power generation system to fully utilize the thermal energy of the exhaust gas after combustion; the cooled exhaust gas obtained after the heat exchange is subjected to CO2 enrichment treatment and collection treatment to achieve near-zero CO2 emissions.

[0068] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0069] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0070] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A combustion device for a SOFC power generation system using carbon-based synthesis gas as fuel, characterized in that: The combustion device comprises a combustion chamber (1), an exhaust gas treatment chamber and an ion igniter (9); the combustion chamber (1) and the exhaust gas treatment chamber are coaxially arranged, and the exhaust gas treatment chamber is arranged on the top of the combustion chamber (1); The tail gas treatment chamber comprises a coaxially arranged ignition gas chamber (8), a cathode tail gas chamber (4), an inner chamber and a tail gas mixing chamber (6); the ignition gas chamber (8), the inner chamber, the tail gas mixing chamber (6) and the cathode tail gas chamber (4) are arranged in sequence from the inside to the outside; a sealing baffle is provided in the inner chamber, and the sealing baffle divides the inner chamber into an anode tail gas chamber (5) and a combustion air chamber (7); An anode tail gas through hole is provided on the inner wall of the tail gas mixing chamber (6), and the cathode tail gas chamber (4) is communicated with the tail gas mixing chamber (6) through the cathode tail gas through hole; a cathode tail gas through hole is provided on the outer wall of the tail gas mixing chamber (6), and the anode tail gas chamber (5) is communicated with the tail gas mixing chamber (6) through the anode tail gas through hole; An ignition gas nozzle (15) is provided at the bottom of the ignition gas chamber (8), and the ignition gas chamber (8) is communicated with the combustion chamber (1) through the ignition gas nozzle (15); an ignition gas pipeline (11) is provided on the side wall of the ignition gas chamber (8) for communicating with an ignition gas source; a combustion air nozzle (16) is provided at the bottom of the combustion air chamber (7), and the combustion air chamber (7) is communicated with the combustion chamber (1) through the combustion air nozzle (16); a mixing gas nozzle (17) is provided at the bottom of the exhaust gas mixing chamber (6) The tail gas mixing chamber (6) is connected to the combustion chamber (1) through the mixed gas nozzle (17); the combustion-supporting air chamber (7) is connected to one end of the cathode tail gas pipeline (12) through the combustion-supporting air pipeline (14), and the other end of the cathode tail gas pipeline (12) is used to be connected to the cathode tail gas outlet of the SOFC power generation system; the cathode tail gas chamber (4) is connected to the cathode tail gas pipeline (12) through the cathode tail gas branch (13); and the anode tail gas chamber (5) is used to be connected to the anode tail gas outlet of the SOFC power generation system through the anode tail gas pipeline (10).

2. The combustion device according to claim 1, characterized in that The combustion device further comprises a UV fire detector (2) for detecting the ignition condition of the combustion device; The UV fire detector (2) is arranged on the outer wall of the combustion chamber (1).

3. The combustion device according to claim 1, characterized in that The ion igniter (9) is arranged inside the ignition gas chamber (8) along the axial direction of the combustion device, and one end of the combustion device extends to the upper part of the combustion chamber (1).

4. The combustion device according to claim 1, characterized in that The combustion chamber (1) and the exhaust gas treatment chamber are respectively cylindrical structures; a circular opening is provided at the top of the combustion chamber (1); and the bottom of the exhaust gas treatment chamber is provided with an area where the ignition gas nozzle (15), the combustion air nozzle (16) and the mixed gas nozzle (17) are overlapped with the circular opening; The combustion chamber (1) further includes a flame stabilizer (3); the flame stabilizer (3) includes a circular concave surface containing a flame guide hole and a flame guide assembly arranged on the back of the circular concave surface; the concave surface of the flame stabilizer (3) faces the bottom of the exhaust gas treatment chamber and the edge of the concave surface of the flame stabilizer (3) is tightly combined with the lower surface of the top surface of the combustion chamber (1); the flame guide hole on the circular concave surface coincides with the flame guide hole on the flame guide assembly.

5. The combustion device according to claim 1, characterized in that Flow regulating valves are respectively provided on the anode tail gas pipeline (10), the ignition fuel gas pipeline (11), the cathode tail gas branch (13) and the combustion-supporting air pipeline (14) to regulate the flow of materials in each pipeline.

6. A method for combustion using the combustion device according to any one of claims 1 to 5, characterized in that: The method includes: S1, allowing the ignition gas to enter the ignition gas chamber (8) through the ignition gas pipeline (11), allowing the cathode tail gas to enter the cathode tail gas pipeline (12), and then enter the combustion chamber (1) through the combustion air pipeline (14) and the combustion air chamber (7), and mix with the ignition gas from the ignition gas chamber (8) to obtain a mixed gas phase; and igniting the mixed gas phase under the action of the ion igniter (9); S2, allowing part of the cathode tail gas in the cathode tail gas pipeline (12) to enter the combustion chamber (1) through the cathode tail gas branch (13), the cathode tail gas chamber (4), and the tail gas mixing chamber (6) to participate in combustion until the temperature of the SOFC power generation system is raised to the operating temperature, and then gradually reducing the flow rate of the ignition gas; S3. When the SOFC power generation system starts to generate power under load, the addition of the ignition gas is stopped, and the anode tail gas entering the anode tail gas chamber (5) through the anode tail gas pipeline (10) and the cathode tail gas in the cathode tail gas chamber (4) are mixed in the tail gas mixing chamber (6) and then enter the combustion chamber (1) to participate in combustion.

7. The method according to claim 6, characterized in that Step S1 also includes causing the ion igniter (9) to ignite the mixed gas phase in the combustion chamber (1) until the UV flame detector of the combustion device detects a flame, and then stopping the ignition process.

8. The method according to claim 6, characterized in that Step S1 further includes, after the cathode tail gas enters the cathode tail gas pipeline (12), opening the flow regulating valve on the combustion air pipeline (14) to allow the cathode tail gas to enter the combustion air chamber (7); The flow regulating valve on the ignition gas pipeline (11) is opened to allow the ignition gas to enter the ignition gas chamber (8).

9. The method according to claim 8, characterized in that Step S2 further includes opening a flow regulating valve on the cathode tail gas branch (13) to allow part of the cathode tail gas to enter the cathode tail gas chamber (4); When the temperature of the SOFC power generation system is raised to the operating temperature, the opening of the flow regulating valve on the ignition gas pipeline (11) is gradually reduced.

10. The method according to claim 9, characterized in that Step S3 also includes, when the SOFC power generation system starts to generate power under load, closing the flow regulating valve on the ignition gas pipeline (11), and opening the flow regulating valve on the anode tail gas pipeline (10), so that the anode tail gas enters the anode tail gas chamber (5).

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