An exhaust gas treatment burner for a SOFC system

Abstract

The application relates to the technical field of solid oxide fuel cell (SOFC) systems, and particularly discloses a tail gas treatment combustor for a SOFC system, which comprises a combustion chamber, one end of the combustion chamber is provided with a gas chamber assembly, the gas chamber assembly is provided with a burner assembly away from the one end of the combustion chamber, the burner assembly is used for feeding a mixture of natural gas and air into the combustion chamber, the burner assembly is provided with an ignition electrode away from the one end of the gas chamber assembly, the ignition electrode extends into the combustion chamber and ignites the mixture of natural gas and air, the gas chamber assembly comprises an anode tail gas chamber and a cathode tail gas chamber, the anode tail gas chamber and the cathode tail gas chamber are coaxially arranged, the anode tail gas chamber is located at an inner layer of the cathode tail gas chamber, the anode tail gas chamber is provided with rotating flow vanes, the anode tail gas chamber is provided with a fire shield away from the one end close to the combustion chamber, the fire shield extends into the combustion chamber, and the fire shield is provided with a plurality of air holes in the circumferential direction. The application has the effect of improving the uniformity of airflow distribution in the combustor.

Description

Technical Field

[0001] This application relates to the field of solid oxide fuel cell (SOFC) system technology, and in particular to an exhaust gas treatment burner for SOFC systems. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are efficient and clean energy conversion devices that produce combustible anode exhaust gas and oxygen-rich cathode exhaust gas during operation. To maintain system thermal balance and treat incompletely reacted fuel, an exhaust gas burner is typically required for exhaust gas treatment.

[0003] In existing burners, the uneven distribution of anode and cathode exhaust gases within the burner can easily cause the flame to deviate to one side, resulting in localized overheating and leading to overheating of the metal walls. Furthermore, prolonged excessively high metal wall temperatures accelerate material aging and may even cause structural failure, thus affecting the burner's lifespan and the system's safe operation. Utility Model Content

[0004] In order to improve the uniformity of airflow distribution within the burner, this application provides an exhaust gas treatment burner for SOFC systems, which has the effect of improving the uniformity of airflow distribution within the burner and extending the service life of the burner.

[0005] This application provides a tail gas treatment burner for SOFC systems, which adopts the following technical solution: A burner for exhaust gas treatment in an SOFC system includes a combustion chamber. A gas chamber assembly is located at one end of the combustion chamber, for introducing anode exhaust gas and cathode exhaust gas into the combustion chamber. A burner assembly is located at the end of the gas chamber assembly away from the combustion chamber, for introducing a mixture of natural gas and air into the combustion chamber. An ignition electrode is located at the end of the burner assembly away from the gas chamber assembly, extending into the combustion chamber and igniting the natural gas and air mixture. The gas chamber assembly includes an anode exhaust gas chamber for introducing anode exhaust gas and a cathode exhaust gas chamber for introducing cathode exhaust gas. The anode exhaust gas chamber and cathode exhaust gas chamber are coaxially arranged, with the anode exhaust gas chamber located inside the cathode exhaust gas chamber. A swirl vane is located within the anode exhaust gas chamber, through which the anode exhaust gas passes before entering the combustion chamber. A flame shield is located at the end of the anode exhaust gas chamber near the combustion chamber, extending into the combustion chamber and covering the outlet end of the cathode exhaust gas chamber. The flame shield has multiple vent holes along its circumference.

[0006] By adopting the above technical solution, after the burner assembly introduces natural gas and air into the combustion chamber, the ignition electrode is activated to ignite the mixture of natural gas and air; subsequently, the anode tail gas generated by the fuel cell stack is introduced into the anode tail gas chamber, and the swirl vanes generate a rotating flow, which evenly delivers the anode tail gas into the combustion chamber. After the cathode exhaust gas is introduced into the cathode exhaust gas chamber, the vent holes on the flame shield help guide the cathode exhaust gas to be evenly dispersed into the combustion chamber, so that the anode exhaust gas and the cathode exhaust gas are fully mixed and burned on the left side of the flame shield. This improves the uniformity and mixing degree of the two gas flows in the burner, reduces the risk of excessive local temperature in the burner, extends the service life of the burner, and effectively reduces the occurrence of backfire.

[0007] Optionally, the burner assembly includes an air chamber, a natural gas gun disposed within the air chamber, and a swirl plate disposed at the outlet end of the air chamber. The air chamber is connected to a supplementary fuel inlet pipe and a supplementary air inlet pipe. One end of the natural gas gun is connected to the supplementary fuel inlet pipe. The swirl plate is located at the outlet end of the air chamber, and one end of the natural gas gun is rotatably connected to the swirl plate.

[0008] By adopting the above technical solution, when air needs to be added, air enters the air chamber through the air inlet pipe; when fuels such as natural gas need to be added, natural gas enters the natural gas gun through the fuel inlet pipe, and then is delivered to the air chamber by the natural gas gun, where the natural gas and air undergo preliminary mixing. The swirl plate can enhance the turbulence of the airflow, which is conducive to promoting the mixing of natural gas and air, so that the mixed natural gas and air can diffuse and burn stably and fully in the combustion chamber.

[0009] Optionally, a connecting chamber is provided in the anode exhaust gas chamber. The connecting chamber is coaxially arranged with the anode exhaust gas chamber. A sealing assembly is provided at the connection between the connecting chamber and the air chamber. The sealing assembly includes a ceramic fiber gasket and fasteners. Flanges are provided at the ends of the connecting chamber and the air chamber that are close to each other. The ceramic fiber gasket is sandwiched between multiple flanges. The multiple flanges are fixedly connected by fasteners.

[0010] By adopting the above technical solution, flanges are installed at the ends of the air chamber and the wind chamber that are close to each other, and then fixed with fasteners to provide a rigid mating structure for the connection between the two, which effectively improves the stability of the connection between the two. The ceramic fiber gasket, as a sealing medium, has high temperature resistance and chemical stability. By sandwiching the ceramic fiber gasket between the flanges, there is no gap between the ceramic fiber gasket and the flange contact surface, which effectively improves the sealing performance of the connection.

[0011] Optionally, the outer wall of the combustion chamber is provided with a pressure tap for connecting a pressure pipe.

[0012] By adopting the above technical solution, the pressure tap can be connected to an external pressure pipe, and with the use of monitoring instruments, it is convenient to capture pressure changes in the combustion chamber in real time, thus ensuring the safety of the combustion chamber.

[0013] Optionally, the outer wall of the combustion chamber is provided with a temperature interface for installing temperature instruments.

[0014] By adopting the above technical solution, the temperature interface facilitates the installation of temperature instruments such as thermocouples, enables real-time monitoring of the temperature inside the combustion chamber, reduces damage such as deformation of the combustion chamber wall material due to high-temperature oxidation, and helps ensure the safety of the combustion chamber.

[0015] Optionally, a saddle support is provided at the bottom of the combustion chamber, and multiple saddle supports are provided, spaced apart, to support the entire burner.

[0016] By adopting the above technical solution, the burner can be supported by multiple saddle supports, which can evenly distribute the weight of the burner, reduce the tilting of the burner, and improve the stability of the burner.

[0017] Optionally, the anode exhaust gas chamber is connected to an anode exhaust gas inlet pipe, and the cathode exhaust gas chamber is connected to a cathode exhaust gas inlet pipe.

[0018] By adopting the above technical solution, the anode exhaust gas inlet pipe and the cathode exhaust gas inlet pipe are two independent structures, which facilitates the control of the input flow rate of the anode exhaust gas and the input flow rate of the cathode exhaust gas, thereby improving combustion efficiency.

[0019] Optionally, the combustion chamber is provided with lifting lugs at the top.

[0020] By adopting the above technical solution, when the inside of the burner needs to be cleaned or parts replaced, the burner can be hoisted and moved as a whole or suspended in a fixed position using the lifting lugs, which reduces the labor intensity of maintenance personnel in moving the burner and helps to shorten maintenance time.

[0021] In summary, this application includes at least one of the following beneficial technical effects: 1. After the burner assembly introduces natural gas and air into the combustion chamber, the ignition electrode is activated to ignite the mixture of natural gas and air. Subsequently, the anode tail gas generated by the fuel cell stack is introduced into the anode tail gas chamber, and the swirl vanes generate a rotating flow, which evenly delivers the anode tail gas into the combustion chamber. After the cathode tail gas is introduced into the cathode tail gas chamber, the vent holes on the flame shield help guide the cathode tail gas to be evenly dispersed into the combustion chamber, so that the anode tail gas and cathode tail gas are fully mixed and burned on the left side of the flame shield. This improves the uniformity and mixing degree of the two airflows in the burner, reduces the risk of local overheating in the burner, and extends the service life of the burner. At the same time, it effectively reduces the occurrence of backfire. 2. When air needs to be added, air enters the air chamber through the air inlet pipe; when fuels such as natural gas need to be added, natural gas enters the natural gas gun through the fuel inlet pipe, and then is delivered to the air chamber by the natural gas gun, where the natural gas and air undergo preliminary mixing. The swirl plate can enhance the turbulence of the airflow, which is conducive to promoting the mixing of natural gas and air, so that the mixed natural gas and air can diffuse and burn stably and fully in the combustion chamber. 3. Flanges are installed at the ends of the air chamber and the wind chamber that are close to each other, and then fixed with fasteners to provide a rigid mating structure for the connection between the two, which effectively improves the stability of the connection. The ceramic fiber gasket, as a sealing medium, has high temperature resistance and chemical stability. By sandwiching the ceramic fiber gasket between the flanges, there is no gap between the ceramic fiber gasket and the flange contact surface, which effectively improves the sealing performance of the connection. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the exhaust gas treatment burner used in the SOFC system in this application; Figure 2 It is along Figure 1 Sectional view of AA; Figure 3 yes Figure 2 Enlarged view of point B in the middle.

[0023] Reference numerals: 1. Combustion chamber; 2. Gas chamber assembly; 201. Anode tail gas chamber; 202. Cathode tail gas chamber; 3. Burner assembly; 301. Air chamber; 302. Natural gas gun; 303. Swirl plate; 4. Ignition electrode; 5. Swirl blade; 6. Flame shield; 7. Vent hole; 8. Supplemental fuel inlet pipe; 9. Supplemental air inlet pipe; 10. Connecting gas chamber; 11. Sealing assembly; 111. Ceramic fiber gasket; 112. Fastener; 12. Flange; 13. Pressure tap; 14. Temperature interface; 15. Saddle support; 16. Anode tail gas inlet pipe; 17. Cathode tail gas inlet pipe; 18. Lifting lug; 19. Flue gas outlet pipe. Detailed Implementation

[0024] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0025] This application discloses an exhaust gas treatment combustor for an SOFC system, referring to... Figure 1The combustion chamber includes a combustion chamber 1, which provides space for the combustion of exhaust gas and fuel. One end of the combustion chamber 1 is provided with a gas chamber assembly 2, and the other end is connected to a flue gas outlet pipe 19. The gas chamber assembly 2 is used to introduce the anode exhaust gas and cathode exhaust gas generated by the fuel cell stack into the combustion chamber 1, and the flue gas outlet pipe 19 is used to discharge the high-temperature flue gas generated in the combustion chamber 1. A burner assembly 3 is provided at the end of the gas chamber assembly 2 away from the combustion chamber 1. The burner assembly 3 is used to mix supplementary fuels such as natural gas with air and then inject it into the combustion chamber 1. An ignition electrode 4 is provided at the end of the burner assembly 3 away from the gas chamber assembly 2. The ignition electrode 4 extends into the combustion chamber 1 and is used to ignite the mixture of natural gas and air.

[0026] Reference Figure 2 and Figure 3 The gas chamber assembly 2 includes a cathode exhaust gas chamber 202 and an anode exhaust gas chamber 201. The cathode exhaust gas chamber 202 and the anode exhaust gas chamber 201 are coaxially arranged, with the cathode exhaust gas chamber 202 located on the outer layer of the anode exhaust gas chamber 201. The cathode exhaust gas chamber 202 is used to introduce the cathode exhaust gas of the fuel cell stack into the combustion chamber 1, and the anode exhaust gas chamber 201 is used to introduce the anode exhaust gas of the fuel cell stack into the combustion chamber 1. The inner wall of the anode exhaust gas chamber 201 is provided with swirl vanes 5, and there are multiple swirl vanes 5, which are evenly distributed in a circular pattern within the anode exhaust gas chamber 201.

[0027] The anode tail gas chamber 201 and the cathode tail gas chamber 202 are arranged in layers to transport the anode tail gas and the cathode tail gas separately, which can avoid the problem of unstable combustion caused by premature mixing of the two tail gases. The swirl vane 5 rotates to evenly introduce the anode tail gas into the combustion chamber 1, which promotes the mixing and complete combustion of the anode tail gas with natural gas and cathode tail gas. The swirl vane 5 generates a higher airflow and has an anti-interference effect, which is conducive to increasing the mixing of natural gas and air in the combustion chamber 1, improving combustion efficiency, and preventing uneven burning.

[0028] Reference Figure 2 and Figure 3 A flame shield 6 is welded and fixed to one end of the anode exhaust gas chamber 201 near the combustion chamber 1. The inner diameter of the flame shield 6 is approximately the same as the outer diameter of the anode exhaust gas chamber 201. The flame shield 6 extends into the combustion chamber 1, and the outer wall of the flame shield 6 abuts against the inner wall of the combustion chamber 1. Ventilation holes 7 are provided on the flame shield 6, and multiple ventilation holes 7 are provided, which are distributed around the circumference of the flame shield 6. The cathode exhaust gas is evenly fed into the combustion chamber 1 in the form of dispersed airflow through the ventilation holes 7, and fully contacts the flame, thereby improving the uniformity of the cathode exhaust gas distribution in the combustion chamber 1. With the rotation of the swirl vanes 5, the anode exhaust gas is evenly fed into the combustion chamber 1, which is conducive to improving the full mixing and combustion of the cathode exhaust gas and the anode exhaust gas, reducing the risk of local overheating in the combustion chamber 1, and extending the service life of the burner.

[0029] Reference Figure 3A connecting chamber 10 is coaxially arranged inside the anode tail gas chamber 201. The length of the connecting chamber 10 is greater than the length of the anode tail gas chamber 201. The swirl vane 5 is located between the outer wall of the connecting chamber 10 and the inner wall of the anode tail gas chamber 201. The swirl vane 5 is welded and fixed to the outer wall of the connecting chamber 10.

[0030] Reference Figure 1 and Figure 3 The burner assembly 3 includes an air chamber 301, a natural gas gun 302, and a swirl plate 303. The air chamber 301 is located at the end of the connecting gas chamber 10 away from the combustion chamber 1. The air chamber 301 is connected to the connecting gas chamber 10 and is used to contain a mixture of natural gas and air, providing space for their mixing. The natural gas gun 302 is installed inside the air chamber 301 and is tubular. The natural gas gun 302 is used to transport natural gas. A supplementary fuel inlet pipe 8 is connected to the outer wall of the air chamber 301, and the natural gas gun 302 is connected to the supplementary fuel inlet pipe 8.

[0031] Reference Figure 1 and Figure 2 The outer wall of the air chamber 301 is connected to a supplementary air inlet pipe 9. The air mixture enters the air chamber 301 through the supplementary air inlet pipe 9 and mixes with the natural gas delivered by the natural gas gun 302. The swirl plate 303 is rotatably connected to the end of the natural gas gun 302 away from the supplementary fuel inlet pipe 8. The swirl plate 303 is located in the connecting gas chamber 10 and at the outlet end of the air chamber 301. The swirl plate 303 helps to enhance the mixing of natural gas and air, so that the fuel and air can fully contact each other before entering the combustion chamber 1, thereby improving the combustion efficiency.

[0032] By setting up the gas chamber assembly 2 and the burner assembly 3, the channels for anode exhaust gas, cathode exhaust gas, supplementary fuel and air are integrated into one unit, which is compact and easy to install in the hot box of the SOFC system, thus reducing costs.

[0033] Reference Figure 1 and Figure 3 A sealing assembly 11 is provided at the end of the air chamber 301 that is close to the connecting air chamber 10. The sealing assembly 11 is used to fix the air chamber 301 and the connecting air chamber 10. The sealing assembly 11 includes a ceramic fiber gasket 111 and a fastener 112. In this embodiment, the fastener 112 is a bolt. Flanges 12 are welded and fixed at the ends of the air chamber 301 and the connecting air chamber 10. The ceramic fiber gasket 111 is sandwiched between the two flanges 12. The two flanges 12 are fixedly connected by the fastener 112.

[0034] When the two flanges 12 are fixed, the ceramic fiber gasket 111 is compressed by tightening the fasteners 112 to fill the gap between the two flanges 12, which helps to prevent gas leakage and improves the air tightness and structural stability of the connection between the air chamber 301 and the communicating air chamber 10.

[0035] In this embodiment, the ignition electrode 4 is welded and fixed to the outer wall of the air chamber 301 away from the connecting air chamber 10. The ignition electrode 4 extends into the air chamber 301 and the connecting air chamber 10 in sequence, and finally penetrates into the combustion chamber 1 to ignite the fuel in the combustion chamber 1. The ignition electrode 4 adopts a high-temperature resistant ignition electrode 4 and a wire to ensure normal operation in a high-temperature environment.

[0036] Reference Figure 1 Multiple saddle supports 15 are welded and fixed to the bottom of the combustion chamber 1. In this embodiment, two saddle supports 15 are provided, and the two saddle supports 15 are located at the bottom of both ends of the combustion chamber 1 respectively. The saddle supports 15 are used to support the entire burner and improve the stability of the burner.

[0037] Reference Figure 1 and Figure 3 An anode exhaust gas inlet pipe 16 passes through the outer wall of the cathode exhaust gas chamber 202 and communicates with the anode exhaust gas chamber 201 through the outer wall of the anode exhaust gas chamber 201. The anode exhaust gas generated by the fuel cell stack is introduced into the anode exhaust gas chamber 201 through the anode exhaust gas inlet pipe 16. A cathode exhaust gas inlet pipe 17 passes through the outer wall of the cathode exhaust gas chamber 202 and communicates with the cathode exhaust gas chamber 202. The cathode exhaust gas generated by the fuel cell stack is introduced into the cathode exhaust gas chamber 202 through the cathode exhaust gas inlet pipe 17. The two exhaust gases mix and burn near the front end of the combustion chamber 1 close to the flame shield 6. The input of the two exhaust gases is two independent structures, which makes it easy to control the flow rate of the two exhaust gases into the combustion chamber 1, thereby improving the combustion efficiency.

[0038] Reference Figure 1 The outer surface of the combustion chamber 1 is provided with a pressure tap 13 and a temperature interface 14. The pressure tap 13 is used to connect to an external pressure tapping pipe. Through the use of the pressure tapping pipe and monitoring instruments, the pressure inside the combustion chamber 1 can be measured to ensure that the pressure inside the combustion chamber 1 is in a safe state. The temperature interface 14 is used to install temperature instruments such as thermocouples to facilitate monitoring the temperature inside the combustion chamber 1. A lifting lug 18 is welded and fixed to the top of the combustion chamber 1. The lifting lug 18 is used to lift the burner to facilitate installation and transportation.

[0039] In this embodiment, all metal parts inside the burner are made of 310S heat-resistant stainless steel, which is beneficial to improving durability and oxidation resistance under high temperature environments.

[0040] The implementation principle of a tail gas treatment burner for an SOFC system disclosed in this application embodiment is as follows: During startup, the natural gas and air mixture injected from the burner assembly 3 is ignited by the ignition electrode 4, providing initial heat to the system. After the system is running normally, the anode tail gas generated by the fuel cell stack enters the anode tail gas chamber 201 through the anode tail gas inlet pipe 16, and the cathode tail gas generated by the fuel cell stack enters the cathode tail gas chamber 202 through the cathode tail gas inlet pipe 17. The anode tail gas passes through the vent hole 7 on the flame shield 6 and enters the combustion chamber 1, while the cathode tail gas enters the combustion chamber 1 through the swirl vanes 5. The two streams... The exhaust gas mixes and burns at the front end of the combustion chamber 1; natural gas and air can be introduced as needed through the supplementary fuel inlet pipe 8 and the supplementary air inlet pipe 9 to participate in combustion and regulate the heat load. The high-temperature flue gas generated by combustion is discharged from the flue gas outlet pipe 19; the flame shield 6 confines the flame to a specific area, effectively reducing flame deviation. At the same time, the anode exhaust gas is introduced into the combustion chamber 1 through the vent hole 7 on the flame shield 6 and the swirl blade 5 is pneumatically rotated by rotating the cathode exhaust gas. Both exhaust gases are evenly integrated into the combustion zone in the form of dispersed airflow, thereby effectively improving the uniformity of exhaust gas distribution in the burner.

[0041] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A tail gas treatment combustor for an SOFC system, characterized in that: The system includes a combustion chamber (1), one end of which is provided with a gas chamber assembly (2). The gas chamber assembly (2) is used to introduce anode exhaust gas and cathode exhaust gas into the combustion chamber (1). A burner assembly (3) is provided at the end of the gas chamber assembly (2) away from the combustion chamber (1). The burner assembly (3) is used to introduce a mixture of natural gas and air into the combustion chamber (1). An ignition electrode (4) is provided at the end of the burner assembly (3) away from the gas chamber assembly (2). The ignition electrode (4) extends into the combustion chamber (1) and ignites the mixture of natural gas and air. The gas chamber assembly (2) includes an anode exhaust gas chamber (201) for introducing anode exhaust gas and a gas chamber for introducing... The cathode exhaust gas chamber (202) is coaxially arranged with the anode exhaust gas chamber (201) and the cathode exhaust gas chamber (202). The anode exhaust gas chamber (201) is located in the inner layer of the cathode exhaust gas chamber (202). A swirl vane (5) is provided in the anode exhaust gas chamber (201). The anode exhaust gas passes through the swirl vane (5) and then enters the combustion chamber (1). A flame shield (6) is provided at one end of the anode exhaust gas chamber (201) near the combustion chamber (1). The flame shield (6) extends into the combustion chamber (1). The flame shield (6) covers the outlet end of the cathode exhaust gas chamber (202). The flame shield (6) has multiple ventilation holes (7) along the circumferential direction.

2. The exhaust gas treatment burner for an SOFC system according to claim 1, characterized in that, The burner assembly (3) includes a wind chamber (301), a natural gas gun (302) disposed in the wind chamber (301), and a swirl plate (303) disposed at the outlet end of the wind chamber (301). A supplementary fuel inlet pipe (8) and a supplementary air inlet pipe (9) are connected to the wind chamber (301). One end of the natural gas gun (302) is connected to the supplementary fuel inlet pipe (8). The swirl plate (303) is located at the outlet end of the wind chamber (301). One end of the natural gas gun (302) is rotatably connected to the swirl plate (303).

3. The exhaust gas treatment burner for an SOFC system according to claim 2, characterized in that, The anode tail gas chamber (201) is provided with a connecting gas chamber (10), which is coaxially arranged with the anode tail gas chamber (201). A sealing assembly (11) is provided at the connection between the connecting gas chamber (10) and the air chamber (301). The sealing assembly (11) includes a ceramic fiber gasket (111) and a fastener (112). Flanges (12) are provided at the ends of the connecting gas chamber (10) and the air chamber (301) that are close to each other. The ceramic fiber gasket (111) is sandwiched between multiple flanges (12), and the multiple flanges (12) are fixedly connected by fasteners (112).

4. The exhaust gas treatment burner for an SOFC system according to claim 1, characterized in that, The outer wall of the combustion chamber (1) is provided with a pressure tap (13) for connecting the pressure pipe.

5. The exhaust gas treatment burner for an SOFC system according to claim 1, characterized in that, The outer wall of the combustion chamber (1) is provided with a temperature interface (14) for installing temperature instruments.

6. The exhaust gas treatment burner for an SOFC system according to claim 1, characterized in that, The combustion chamber (1) is provided with a saddle support (15) at the bottom. Multiple saddle supports (15) are provided and spaced apart. The multiple saddle supports (15) are used to support the entire burner.

7. The exhaust gas treatment burner for an SOFC system according to claim 1, characterized in that, The anode tail gas chamber (201) is connected to an anode tail gas inlet pipe (16), and the cathode tail gas chamber (202) is connected to a cathode tail gas inlet pipe (17).

8. The exhaust gas treatment burner for an SOFC system according to claim 1, characterized in that, The combustion chamber (1) is provided with a lifting lug (18) at the top.

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