CN113483324B

CN113483324B - Tail gas burner

Info

Publication number: CN113483324B
Application number: CN202110805933.8A
Authority: CN
Inventors: 邓炜; 叶爽; 庄晓杰; 李银宾; 陈静薇; 黄伟光
Original assignee: Shanghai Advanced Research Institute of CAS
Current assignee: Shanghai Advanced Research Institute of CAS
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2022-12-20
Anticipated expiration: 2041-07-16
Also published as: CN113483324A

Abstract

The invention discloses a tail gas burner which comprises an on-duty flame nozzle, a tail gas nozzle assembly arranged on the periphery of the on-duty flame nozzle, a combustion chamber arranged behind the on-duty flame nozzle and the tail gas nozzle assembly, and a secondary air countercurrent channel arranged on the outer side of the combustion chamber and communicated with the combustion chamber, wherein the tail gas nozzle is arranged at the rear end of the tail gas nozzle assembly and comprises an anode tail gas channel and a cathode tail gas channel, and the stable combustion of tail gas sprayed out by the tail gas nozzle is realized by controlling the combustion degree of the on-duty flame nozzle. According to the invention, the on-duty flame nozzle is arranged at the central position of the tail gas burner, and the tail gas nozzle assembly is arranged at the periphery of the on-duty flame nozzle, so that the on-duty flame nozzle is beneficial to igniting the outer tail gas, and the purpose of organizing the tail gas to carry out stable combustion by controlling the combustion degree of the on-duty flame nozzle is further realized.

Description

Tail gas burner

Technical Field

The invention relates to the technical field of combustion, in particular to a tail gas combustor for a fuel cell.

Background

The fuel cell can directly convert the chemical energy of the fuel into electric energy without the restriction of Carnot cycle effect, and belongs to a high-efficiency power generation technology. During use, the fuel cell discharges combustible gas containing hydrogen, carbon monoxide and the like (i.e., anode off-gas) from the anode, and also discharges a mixture of oxygen and nitrogen (i.e., cathode off-gas) from the cathode. Because positive pole tail gas and negative pole tail gas all have higher enthalpy, consequently, for improving fuel cell generating efficiency to accord with the environmental protection requirement simultaneously, generally can take the mode of tail gas burning to handle fuel cell exhaust tail gas, simultaneously, solid oxide fuel cell is at normal electricity generation operation in-process, need preheat in advance fuel and the air that gets into the battery, after the fuel cell electricity generation, only tail gas carries out the backheat and utilizes, just can accord with its high-efficient clear advantage.

The anode tail gas generated in the power generation process of the fuel cell has low calorific value of combustible gas (such as hydrogen, carbon monoxide and the like) and has large content of components. For example, hydrogen from the reformer may electrochemically react with oxygen to generate water, so that only a small amount of hydrogen, carbon monoxide and a large amount of moisture remain in the combustible gas, and thus the anode off-gas has a low heating value and a large change in composition. In addition, during the operation of the fuel cell, the change of the working condition can also cause the change of parameters such as the components, the calorific value and the like of the anode tail gas. In the operation process of the fuel cell, parameters such as components, heat value and the like of anode tail gas are changed, so that the stability of tail gas combustion is difficult to control, even phenomena such as tempering or flameout can occur, and the phenomena can cause the fuel cell to work abnormally and even cause safety accidents such as damage and the like. The sofc generally needs to burn fuel (such as CH 4) to provide the required heat energy for its reformer at the initial startup, and the tail gas burner preferably can be compatible with the fuel combustion, simplifying the system.

Therefore, the tail gas burner of the fuel cell becomes a key technology of the fuel cell.

Disclosure of Invention

The invention aims to solve the technical problems that the existing tail gas combustor can not organize tail gas, particularly low-calorific-value tail gas, and can stably combust when component parameters change, so that potential safety hazards such as flameout and tempering can not be eliminated in the tail gas combustion process, and in addition, the combustion of fuel is considered when a reformer is started.

In order to solve the technical problem, the invention provides a tail gas combustor, which comprises an on-duty flame nozzle, a tail gas nozzle assembly arranged at the periphery of the on-duty flame nozzle, a combustion chamber arranged behind the on-duty flame nozzle and the tail gas nozzle assembly, and a secondary air countercurrent channel arranged outside the combustion chamber and communicated with the combustion chamber, wherein the tail gas nozzle is arranged at the rear end of the tail gas nozzle assembly and comprises an anode tail gas channel and a cathode tail gas channel, and the stable combustion of tail gas sprayed out by the tail gas nozzle is realized by controlling the combustion degree of the on-duty flame nozzle.

Preferably, the flame nozzle on duty includes from interior to exterior in proper order the suit center tube, interior sleeve pipe and outer tube, the center tube with form the primary air passageway between the interior sleeve pipe, form the fuel passageway between interior sleeve pipe and the outer tube, the rear end is provided with first connecting portion between interior sleeve pipe and the outer tube, be provided with the fuel orifice on the first connecting portion, the fuel passageway with the combustion chamber passes through the fuel orifice intercommunication, be provided with pulse igniter in the center tube.

Preferably, the fuel injection holes are a plurality of first micro-holes uniformly arranged on the first connecting portion, and all the first micro-holes are not in the same plane with the central axis of the central tube.

Preferably, a rotating blade is arranged in each of the primary air channel and the secondary air upstream channel.

Preferably, the tail gas nozzle assembly comprises a cylindrical structure sleeved on the on-duty flame nozzle, the front section of the cylindrical structure is separated into an anode gas collection chamber and a cathode gas collection chamber by a chamber partition plate, the anode gas collection chamber is provided with an anode tail gas inlet, the cathode gas collection chamber is provided with a cathode gas collection chamber inlet, and the tail gas nozzle is arranged at the rear section of the cylindrical structure.

Preferably, the tail gas nozzle comprises a plurality of annular pipes which are sequentially sleeved on the periphery of the on-duty flame nozzle from inside to outside, a plurality of tail gas channels are formed between the annular pipes, each tail gas channel comprises an anode tail gas channel and a cathode tail gas channel, the anode tail gas channels and the cathode tail gas channels are arranged at intervals, and a second connecting part is arranged between the annular pipes, so that the anode gas collection chamber and the anode tail gas channels are in a communicated state and are in a non-communicated state, and the cathode gas collection chamber and the cathode tail gas channels are in a communicated state and are in a non-communicated state.

Preferably, the rear end of the anode tail gas channel is provided with a third connecting part, the third connecting part is provided with a plurality of second micro-holes, and the anode tail gas channel is communicated with the combustion chamber through the second micro-holes.

Preferably, an air inlet cylinder is sleeved on the periphery of the combustion chamber, a secondary air backflow channel is formed between the air inlet cylinder and the combustion chamber, and the secondary air backflow channel is communicated with the combustion chamber.

Preferably, the combustion chamber end is provided with a converging nozzle.

Preferably, rotating blades are arranged in the anode tail gas channel and the cathode tail gas channel.

Compared with the prior art, one or more embodiments in the above scheme can have the following advantages or beneficial effects:

by applying the tail gas burner provided by the embodiment of the invention, the on-duty flame nozzle is arranged at the central position of the tail gas burner, and the tail gas nozzle assembly is arranged at the periphery of the on-duty flame nozzle, so that the on-duty flame nozzle is favorable for igniting the outer tail gas, the purpose of organizing the tail gas to carry out stable combustion by controlling the combustion degree of the on-duty flame nozzle is further realized, and the effect of stable combustion can be achieved under the conditions that the anode tail gas has low heat value, and the parameters such as components, heat value and the like are changed. And further, the distances between an anode tail gas channel and a cathode tail gas channel in the tail gas nozzle and the on-duty flame nozzle are gradually increased, so that the tail gas output by each channel has an independent combustion space, the tail gas combustion reaction is dispersed in the combustion chamber as much as possible, the stability of flame is improved, the combustion intensity of each point is distributed more reasonably in the space, local high-temperature burning loss parts are avoided, and the emission of excessive nitrogen oxides is reduced.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

FIG. 1 shows an overall cross-sectional view of a tail gas burner according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a mid-span flame nozzle in a tail gas burner according to an embodiment of the invention;

FIG. 3 illustrates a cross-sectional view of a tail gas nozzle assembly in a tail gas burner according to an embodiment of the present invention;

FIG. 4 shows a cross-sectional view of an anode tail gas channel in a tail gas nozzle of a tail gas burner according to an embodiment of the present invention;

description of reference numerals:

1 is an on-duty flame nozzle, 11 is a central tube, 12 is an inner sleeve, 13 is an outer sleeve, 14 is a primary air channel, 15 is a fuel channel, 16 is a fuel nozzle, and 17 is a first connecting part; 2 is a tail gas nozzle component, 21 is an anode gas collection chamber, 22 is a cathode gas collection chamber, 23 is a chamber partition plate, 24 is a tail gas nozzle, 240 is a second connecting part, 241 is a central sleeve, 242 is an anode tail gas channel, 243 is a cathode tail gas channel, 244 is an anode nozzle, 245 is a cathode nozzle, 246 is an anode tail gas inlet, 247 is a cathode tail gas inlet, 248 is a third connecting part, and 249 is a second micro-pore channel; 3 is a combustion chamber, 31 is a contraction nozzle, 32 is a secondary air countercurrent channel, and 33 is an air inlet cylinder; 4 is a rotary blade.

Detailed Description

The following detailed description of the embodiments of the present invention will be provided with reference to the drawings and examples, so that how to apply the technical means to solve the technical problems and achieve the technical effects can be fully understood and implemented. It should be noted that, as long as there is no conflict, the embodiments and the features of the embodiments of the present invention may be combined with each other, and the technical solutions formed are within the scope of the present invention. The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

The tail gas generated by the fuel cell needs to be recycled to meet the advantages of high efficiency and cleanness. However, the fuel cell generates anode off-gas during power generation, which contains combustible gases (such as hydrogen, carbon monoxide, etc.) with low calorific value and widely varying component contents. For example, hydrogen from the reformer may electrochemically react with oxygen to produce water, leaving the combustible gas with only a small amount of hydrogen, carbon monoxide, and a large amount of moisture. Thereby causing the heat value of the anode tail gas to be greatly changed. In addition, in the operation process of the fuel cell, the change of working conditions can also cause the change of parameters such as components, heat value and the like of the anode tail gas. During the operation of the fuel cell, parameters such as components and calorific value of anode tail gas change, which can cause the difficulty in controlling the combustion stability of the tail gas, even cause the phenomena of tempering or flameout, etc., which can cause the safety accidents such as the failure of the normal operation of the fuel cell, even damage, etc.

Example one

In order to solve the technical problems in the prior art, the embodiment of the invention provides a tail gas combustor.

FIG. 1 shows an overall cross-sectional view of a tail gas burner according to an embodiment of the present invention; referring to fig. 1, the tail gas burner according to the embodiment of the present invention includes an on-duty flame nozzle 1, a tail gas nozzle assembly 2, and a combustion chamber 3, where the tail gas nozzle assembly 2 is disposed at the periphery of the on-duty flame nozzle 1, and the combustion chamber 3 is disposed behind the on-duty flame nozzle 1 and the tail gas nozzle assembly 2 to provide a combustion space for combustion of tail gas and on-duty flame, the on-duty flame nozzle 1 is configured to control a combustion degree to implement stable combustion of tail gas sprayed from the tail gas nozzle, and the tail gas nozzle assembly 2 is configured to combust tail gas, and by controlling anode tail gas flow and cathode tail gas flow, anode tail gas and cathode tail gas are ensured to be close to a chemical equivalent value of sufficient combustion, so that tail gas combustion is more sufficient.

The flame nozzle 1 on duty is mainly used for stabilizing combustion. FIG. 2 illustrates a cross-sectional view of a pilot flame nozzle in an exhaust gas burner in accordance with an embodiment of the invention; referring to fig. 2, the on-duty flame nozzle 1 includes a central tube 11, an inner sleeve 12 and an outer sleeve 13, and a pulse igniter is disposed in the central tube 11, so that ignition and combustion of the on-duty flame nozzle 1 can be realized. The inner sleeve 12 is sleeved outside the central tube 11, and forms a primary air channel 14 with the central tube 11, and the end of the primary air channel 14 is opened to be used as a nozzle of the primary air channel 14. And it is preferable that the rotating blades 4 having a certain swirling angle are provided in the primary air passage 14, and a swirling flow is generated when primary air having a certain pressure passes through. The outer sleeve 13 is sleeved outside the inner sleeve 12, a fuel channel 15 is formed between the outer sleeve and the inner sleeve 12, a first connecting portion 17 is arranged at the rear end of the fuel channel 15, a fuel nozzle is arranged on the first connecting portion 17, and the fuel channel 15 is communicated with the combustion chamber 3 through the fuel nozzle. Note that the first connection portion is not provided at the tip of the fuel passage 15, i.e., the fuel nozzle hole and the fuel passage tip together constitute the fuel nozzle 16. The further fuel spray holes are a plurality of first micro-hole channels uniformly arranged on the first connecting portion 17, and the axes of all the first micro-hole channels are not in the same plane with the central axis of the central tube, so that the fuel gas in the fuel channel 15 is sprayed out along the first micro-hole channels, the fuel gas can form a rotational flow with a certain strength around the central axis, and a backflow area generated by the rotational flow can also play a role in stabilizing flame. And further, by designing the rotational flow strength of primary air and fuel, the shape of flame generated by the on-duty flame nozzle 1 can be controlled, and the effect of stabilizing the flame combustion of the whole burner is achieved.

The structure of the on-duty flame nozzle 1 realizes a diffusion flame combustion mode, and when the fuel in the fuel channel 15 is selected from the fuel (such as CH 4) of the fuel cell, the fuel source can be ensured to be reliable, and parameters such as flow, components, pressure and temperature of the fuel can be ensured to be stable, so that the whole combustor can be stably combusted, and flameout can be avoided. Meanwhile, in order to keep the stable combustion of the whole combustor, the combustion power of the flame nozzle 1 on duty can be adjusted within the range of 5% -50% of the power of the whole combustor, and heating energy can be provided for the fuel cell reformer when the reformer is started. And the fuel nozzle 16 is arranged outside the primary air, which is also helpful for igniting the tail gas nozzle and ensures the stable combustion of the tail gas.

The exhaust nozzle assembly 2 is used to collect the exhaust gas and output it as fuel. FIG. 3 illustrates a cross-sectional view of a tail gas nozzle assembly in a tail gas burner according to an embodiment of the present invention; referring to fig. 1 and 3, the exhaust nozzle assembly 2 is disposed at the periphery of the on-duty flame nozzle 1. The front end of the tail gas nozzle component 2 is provided with an anode gas collection chamber 21 and a cathode gas collection chamber 22 to realize the collection of the tail gas of the fuel cell. The rear end of the exhaust nozzle assembly 2 is provided with an exhaust nozzle 24 for distributing and outputting the exhaust as fuel. Preferably, the whole exhaust nozzle assembly may include a cylindrical structure sleeved on the outer sleeve 13 of the flame nozzle 1 on duty, the front section of the exhaust nozzle assembly 2 is divided into an anode gas collection chamber 21 and a cathode gas collection chamber 22 by a chamber partition plate 23, the front end of the anode gas collection chamber 21 is communicated with an anode exhaust gas inlet 246, and the front end of the cathode gas collection chamber 22 is communicated with a cathode exhaust gas inlet 247.

The tail gas nozzle 24 can realize the diffusion combustion of the anode tail gas and the cathode tail gas. Specifically, the flame nozzle comprises a plurality of annular pipes which are sequentially sleeved from inside to outside, wherein the annular pipe at the innermost side is a central sleeve 241, and the central sleeve 241 is sleeved on an outer sleeve 13 of the flame nozzle 1 on duty. A plurality of exhaust gas passages are formed between the plurality of annular pipes, and the plurality of exhaust gas passages may be disposed as an anode exhaust gas passage 242 and a cathode exhaust gas passage 243, and the anode exhaust gas passage 242 and the cathode exhaust gas passage 243 are disposed at intervals. Second connecting parts 240 are arranged among the annular pipes, and the second connecting parts 240 can be arranged so that the anode gas collecting chamber 21 is only communicated with the anode tail gas channel 242, and the cathode gas collecting chamber 22 is only communicated with the cathode tail gas channel 243; that is, the second connection portion 240 is arranged such that the anode plenum 21 is not communicated with the cathode tail gas channel 243, and the cathode plenum 22 is not communicated with the anode tail gas channel 242, so that the anode tail gas and the cathode tail gas are output from different channels respectively, so as to avoid backfire and deflagration caused by mixing of the anode and the cathode tail gases.

It should be noted that the end of the central sleeve 241 is longer than the end of the outer sleeve 13 in the on-duty flame nozzle 1, and the ends of the annular sleeves serving as the outer annular sleeves are longer than the ends of the adjacent inner annular sleeves in the plurality of sleeved annular sleeves, so that the end of the on-duty flame nozzle and the end of the tail gas nozzle assembly form a concave shape together.

FIG. 4 shows a cross-sectional view of an anode tail gas channel in a tail gas burner tail gas nozzle in accordance with an embodiment of the present invention; referring to fig. 4, a third connection portion 248 is disposed at an end of the anode tail gas channel 242, a plurality of second micro-holes 249 are disposed on the third connection portion 248, and the anode tail gas channel 242 communicates with the combustion chamber 3 through the second micro-holes 249. It should be noted that the third connection portion is not disposed at the end of the anode off-gas channel 242, that is, the second micro-duct 249 and the end of the anode off-gas channel 242 together form the anode nozzle 244, and the end opening of the cathode off-gas channel 243 is used as the cathode nozzle 245. The second micro-channel 249 is a straight-through channel with a diameter of about 1 mm. The second micro-holes 249 are designed to ensure uniform flow distribution in space and to prevent back-fire. Further, the anode off-gas passage 242 and the cathode off-gas passage 243 are provided with the rotary vanes 4 therein. The rotating blades arranged in the anode tail gas channel and the cathode tail gas channel are used for enabling tail gas to form rotational flow in the channels and controlling tail gas flow speed, and are also used for enabling anode tail gas to be uniformly distributed in the anode tail gas channel and enabling cathode tail gas to be uniformly distributed in the cathode tail gas channel. It should be noted that by designing the rotating vanes 4 and the second micro-ducts 249 in the anode tail gas channel 242 and the cathode tail gas channel 243, etc., the cathode tail gas flow output by each cathode tail gas channel 243 corresponds to the anode tail gas flow output by the adjacent anode tail gas channel 242, and the anode tail gas and the cathode tail gas are ensured to be close to the stoichiometric value of sufficient combustion, so that the stoichiometric value of the whole tail gas nozzle 24 is ensured, and the requirement of stable combustion of the anode tail gas with low heat value and low combustible component concentration is further met. Further anode nozzle 244 and cathode nozzle 245 interval set up, and increase gradually with central sleeve 241's axial distance, can guarantee that every tail gas nozzle has independent combustion space for tail gas combustion reaction disperses as far as possible in combustion chamber 3, has improved flame's stability, and makes each point intensity of combustion distribute more rationally in the space, avoids local high temperature to burn and decreases the emission of excessive nitrogen oxide. In the use process of the fuel cell, the generated anode tail gas contains combustible gases such as hydrogen, carbon monoxide and the like, and the cathode tail gas contains residual oxygen and nitrogen after the electrochemical reaction of the fuel cell. Thus, the cathode nozzle 245 actually provides oxygen for the combustion of the anode nozzle 244 when the tail gas combustor is processing the fuel cell tail gas.

It should be further noted that the center sleeve 241 of the anode nozzle 244 set may be used as the outer sleeve 13 of the on-duty flame nozzle 1, or the outer sleeve 13 of the on-duty flame nozzle 1 may be used as the center sleeve 241 of the anode nozzle 244 set.

The combustion chamber 3 is a space where the tissue is burned. Specifically, the combustion chamber 3 may be a cylindrical structure, and the front end thereof is connected to the outside of the exhaust nozzle assembly 2, and the tail end thereof is provided with a contraction nozzle 31. The contraction nozzle 31 can enable combustion flue gas to run to the end of the combustion chamber 3 to be extruded, backflow is formed in the middle of the combustion chamber, gas flowing in the combustion chamber is accelerated, high-temperature hot spots are eliminated, generation of nitrogen oxides in combustion reaction is reduced, the temperature of tail gas in the combustion chamber is increased, and combustion intensity and combustion efficiency are improved. Further, an air inlet barrel 33 is arranged on the periphery of the combustion chamber 3. The air inlet cylinder 33 is sleeved on the periphery of the combustion chamber 3, the front end of the air inlet cylinder is connected with the outer side of the tail gas nozzle component 2, an air inlet is formed between the front end of the combustion chamber 3 and the tail gas nozzle component 2, a secondary air backflow channel 32 is formed between the air inlet cylinder 33 and the combustion chamber 3, and the secondary air backflow channel 32 is communicated with the combustion chamber 3 and used for providing secondary air for the combustion chamber 3 and cooling the wall surface of the combustion chamber so as to avoid damage to devices due to overhigh temperature, improve the temperature of the secondary air and contribute to improving the combustion efficiency. Preferably, at the front end of the combustion chamber 3, the secondary air counterflow channel 32 is provided with a rotating blade 4 in the channel baffling into the combustion chamber, which can play the role of uniformly distributing and adjusting the gas flow rate in the secondary air counterflow channel 32, and simultaneously can also make the burned flue gas form entrainment, playing the role of strengthening the gas flow in the combustion chamber and balancing the temperature in the combustion chamber.

It should be noted that the secondary air can make the tail gas combustor have a certain excess air coefficient, ensure the combustion efficiency in the combustion chamber 3, and can achieve the purpose of controlling the exhaust temperature after combustion, thereby meeting the requirements of the subsequent process. The overgrate air comes from the external air, and its passageway counter-current formula is arranged in the combustion chamber 3 outside, through the wall heat transfer between the two, can be to improving the overgrate air temperature, also can cool off 3 walls of combustion chamber simultaneously, avoids the super temperature scaling loss.

According to the tail gas burner provided by the embodiment of the invention, the shift flame nozzle is arranged at the central position of the tail gas burner, and the tail gas nozzle assembly is arranged at the periphery of the shift flame nozzle, so that the shift flame nozzle is favorable for igniting the outer tail gas, the purpose of organizing the tail gas to carry out stable combustion by controlling the combustion degree of the shift flame nozzle is further realized, and the effect of stably combusting the tail gas is still achieved under the conditions that the anode tail gas has low heat value, and the parameters such as components, heat value and the like are changed. And further, the distances between an anode tail gas channel and a cathode tail gas channel in the tail gas nozzle and the on-duty flame nozzle are gradually increased, so that the tail gas output by each channel has an independent combustion space, the tail gas combustion reaction is dispersed in the combustion chamber as much as possible, the stability of flame is improved, the combustion intensity of each point is distributed more reasonably in the space, local high-temperature burning loss parts are avoided, and the emission of excessive nitrogen oxides is reduced.

And the arrangement of the rotating blades with certain different rotation angles in the anode tail gas channel, the cathode tail gas channel, the secondary air counter-current channel and the primary air channel can play a role of uniformly distributing the gas flow velocity in each channel on one hand, and can also enable the burned flue gas to generate backflow on the other hand, thereby achieving the purposes of stabilizing combustion, controlling combustion intensity and improving combustion efficiency.

In the description of the present invention, it should be noted that the terms "first", "second" and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A tail gas burner is characterized by comprising an on-duty flame nozzle, a tail gas nozzle assembly arranged on the periphery of the on-duty flame nozzle, a combustion chamber arranged behind the on-duty flame nozzle and the tail gas nozzle assembly, and a secondary air countercurrent channel arranged on the outer side of the combustion chamber and communicated with the combustion chamber, wherein the tail gas nozzle is arranged at the rear end of the tail gas nozzle assembly and comprises an anode tail gas channel and a cathode tail gas channel, and the stable combustion of tail gas sprayed out by the tail gas nozzle is realized by controlling the combustion degree of the on-duty flame nozzle;

the tail gas nozzle assembly comprises a cylindrical structure sleeved on the on-duty flame nozzle, and the front section of the cylindrical structure is divided into an anode gas collection chamber and a cathode gas collection chamber by a chamber partition plate;

the tail gas nozzle comprises a plurality of annular pipes which are sequentially sleeved on the periphery of the on-duty flame nozzle from inside to outside, a plurality of tail gas channels are formed between the annular pipes, each tail gas channel comprises an anode tail gas channel and a cathode tail gas channel, the anode tail gas channels and the cathode tail gas channels are arranged at intervals, second connecting parts are arranged between the annular pipes, so that the anode gas collection chamber and the anode tail gas channels are in a communicated state and are in a non-communicated state, the cathode gas collection chamber and the cathode tail gas channels are in a communicated state and are in a non-communicated state, and the tail gas nozzle realizes diffusion combustion of anode tail gas and cathode tail gas;

the ends of the annular sleeves when used as outer annular sleeves of the plurality of sleeved annular sleeves are all longer than the ends of the adjacent inner annular sleeves, so that the ends of the flame nozzle on duty and the tail gas nozzle assembly form a concave shape together.

2. The tail gas burner of claim 1, wherein the on-duty flame nozzle comprises a central tube, an inner tube and an outer tube which are sequentially sleeved from inside to outside, a primary air channel is formed between the central tube and the inner tube, a fuel channel is formed between the inner tube and the outer tube, a first connecting portion is arranged at the rear end between the inner tube and the outer tube, a fuel nozzle hole is arranged on the first connecting portion, the fuel channel is communicated with the combustion chamber through the fuel nozzle hole, and a pulse igniter is arranged in the central tube.

3. The exhaust burner of claim 2, wherein the fuel orifices are a plurality of first micro-tunnels uniformly disposed on the first connection portion, all of the first micro-tunnels axes being not coplanar with the central tube central axis.

4. The exhaust gas burner of claim 2, wherein a rotating blade is disposed in each of the primary air passage and the secondary air counterflow passage.

5. The exhaust gas burner of claim 1, wherein the anode plenum is provided with an anode exhaust gas inlet, the cathode plenum is provided with a cathode plenum inlet, and the exhaust gas nozzle is disposed at the rear section of the tubular structure.

6. The tail gas burner of claim 5, wherein a third connecting portion is disposed at a rear end of the anode tail gas channel, and a plurality of second micro-holes are disposed on the third connecting portion, and the anode tail gas channel is communicated with the combustion chamber through the second micro-holes.

7. The exhaust gas burner of claim 1, wherein an air inlet barrel is sleeved around the combustion chamber, a secondary air backflow passage is formed between the air inlet barrel and the combustion chamber, and the secondary air backflow passage is communicated with the combustion chamber.

8. The exhaust gas burner of claim 1, wherein the combustion chamber is provided with a converging nozzle at the end.

9. The exhaust gas burner according to any one of claims 1 to 8, wherein rotating vanes are provided in the anode exhaust gas passage and the cathode exhaust gas passage.