CN115127101A

CN115127101A - Burner for low calorific value waste gas fuel

Info

Publication number: CN115127101A
Application number: CN202110326889.2A
Authority: CN
Inventors: 韩啸; 宋恒; 周宇晨; 林宇震
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2022-09-30

Abstract

The invention relates to the technical field of waste gas combustion equipment, in particular to a burner for low-calorific-value waste gas fuel, which comprises a combustion chamber, a swirler, a fuel pipe and an air pipe, wherein the fuel pipe and the air pipe are communicated with the combustion chamber, and the swirler is arranged in the fuel pipe so as to promote the waste gas fuel flowing in the fuel pipe to form a swirling flow and then enter the combustion chamber to form a backflow zone and be mixed with air jetted from the air pipe. The burner for the low-heat-value waste gas fuel can realize a combustion environment suitable for the low-heat-value waste gas fuel, ensure that the air flow formed in the combustion environment is far smaller than the flow of the low-heat-value waste gas fuel, and ensure the stable combustion of the low-heat-value waste gas fuel even if combustion improver is not added.

Description

Burner for low calorific value waste gas fuel

Technical Field

The invention relates to the technical field of waste gas combustion equipment, in particular to a burner for low-calorific-value waste gas fuel.

Background

In the prior art, part of waste gas produced in industry needs to be burnt to remove harmful pollutants and then can be discharged outwards, or can be recycled after being burnt to remove harmful pollutants, the burning of the waste gas generally needs to pass through a burner, and the waste gas is input into a combustion chamber and simultaneously is accompanied with input oxidant (air) in the combustion process, so that the waste gas and the oxidant (air) are mixed with each other continuously, and the waste gas can be combusted continuously. However, the industrial waste gas can be roughly divided into high-calorific-value waste gas and low-calorific-value waste gas, the high-calorific-value waste gas has stable flame and is easy to burn in the burning process, most of burners in the prior art can effectively process the high-calorific-value waste gas, and in contrast, the flame of the low-calorific-value waste gas is extremely unstable and difficult to stabilize in the burning process, and the traditional burner is difficult to burn the high-calorific-value waste gas efficiently, so that people select to directly discharge the low-calorific-value waste gas in some cases, and huge energy waste is caused. For example, the exhaust gas generated by the fuel cell contains a small amount of combustible components such as methane and hydrogen, has high temperature and humidity, and can be reused after combustion, and particularly in the distributed power generation system, the high-temperature exhaust gas generated by the fuel cell is further combusted, pollutants in the exhaust gas are removed, and the waste heat generated during combustion can preheat the intake air of the fuel cell, so that the efficiency of the distributed power generation system can be effectively improved. It should be noted that, since the high-temperature exhaust gas generated by the fuel cell is low-heat value exhaust gas, which contains only a very small amount of combustible components, too much air (oxidant) cannot be input during the combustion process, and only a small amount of air (oxidant) needs to be provided to ensure the feasibility of ignition and the stable combustion of flame, therefore, the flow rate of the exhaust gas is much larger than that of the air (oxidant) during the combustion of the low-heat value exhaust gas fuel.

The prior art also provides various proposals for the combustion of low-calorific-value waste gas fuel, for example, a granted patent with a patent number of 201921410963.3 discloses a novel low-calorific-value burner, as shown in fig. 1 and 2, the low-calorific-value burner of the proposal comprises a shell 1 and a nozzle formed by connecting a first combustion pipe 8 and a second combustion pipe 11 through threads, wherein, the surface of the first combustion pipe 8 is provided with combustion holes 9; the left end of the second combustion pipe 11 is provided with a through hole 13 for circulating air provided by a fan 14; the second combustion pipe 11 is also provided with a gas delivery device a and a feed gate 24. The combustion mode is as follows: the gas conveying device A controls the flow of gas, the gas enters the first combustion pipe 8 and the second combustion pipe 11, then the heating switch 6 is turned on, the heating resistance wire 5 starts to work to preheat the gas, the gas is ignited through the electric arc igniter 7 after being preheated for a period of time, and the fan 14 is started after ignition to convey air into the first combustion pipe 8 and the second combustion pipe 11. If the addition of the comburent is required, the feed gate 24 may be opened to add the comburent to the interior.

Referring to fig. 1 and 2, fuel and air are introduced into the first combustion pipe 8 and the second combustion pipe 11 to be mixed and combusted. However, the invention does not design a physical structure or a pneumatic structure for stabilizing the flame, the stable position of the flame is greatly influenced by the flow of the mixture, and the flame stability is poor; the invention does not have the design of enhancing the mixing effect of the fuel and the air, often needs to add a combustion supporter for supporting combustion, and cleans residues after the combustion is finished, which is time-consuming.

Also for example, the patent number of the patent No. cn200610011661.x discloses a nozzle structure and a combustion method for a low-heat value combustor of a gas turbine, as shown in fig. 3, the low-heat value combustor of the scheme includes a housing a and a nozzle B, wherein the nozzle B includes a radial swirler 1, a swirler passage 4, a first row of fuel holes 3 and a second row of fuel holes 6. The combustion mode is as follows: the primary air 5 flowing through the radial swirler 1 enters the swirler passage 4, and the first exhaust gas fuel jet 2 enters the swirler passage 4 through the first exhaust fuel hole 3 to form a rich premixed gas with the primary air 5; the second exhaust fuel jet 7 enters the housing a through the second exhaust fuel hole 6 for combustion.

Referring to fig. 3, in this embodiment, primary air 5 flowing through the radial swirler 1 is mixed with the first exhaust fuel jet 2 and the second exhaust fuel jet 7. In the invention, the flow channels of the first row of fuel holes 3 and the second row of fuel holes 6 are communicated. When the combustor works at low load, only the second row of fuel holes 6 are in a circulating state; when the combustor works at high load, the first row of fuel holes 3 and the second row of fuel holes 6 are in a circulation state; therefore, the fuel hole of the nozzle needs to be opened and closed, so that the structure is more complex, the cost is higher, and the reliability is poorer; furthermore, the first exhaust gas fuel jet 2 and the primary air 5 form a rich premixed gas in the swirler passage 4, which is prone to flashback, so that combustion takes place in the swirler passage 4, destroying the nozzle structure. More importantly, when the calorific value of the waste gas fuel is very low (such as the waste gas after the fuel cell reaction), and the air flow required for combustion is much smaller than the flow rate of the waste gas fuel, the primary air 5 flowing through the radial swirler 1 and the first and second waste

gas fuel jets

2 and 7 hardly have a sufficiently large swirl number, resulting in poor flame stability.

To sum up, in the conventional burner in the prior art, the combustion organization is usually to flow air (oxidant) through the swirler to form a swirl and form a recirculation zone in the combustion chamber, in order to make the air (oxidant) have sufficient swirl strength after flowing through the swirler, the air flow is often required to be increased, so that the content ratio of the air (oxidant) in the combustion chamber is higher, and the exhaust gas fuel is directly injected into the combustion chamber in a common injection manner to form a jet flow, so that the content ratio of the combustible (exhaust gas fuel) in the combustion chamber is lower, and when the exhaust gas fuel with a low calorific value is combusted in the combustion manner, the flame is unstable and difficult to combust smoothly, in order to solve the problem, the prior art has to additionally add a combustion supporter into the combustion chamber, and finally causes residue after the combustion is finished, the combustion chamber needs to be cleaned each time, time and labor are wasted, and the efficiency is low.

Disclosure of Invention

The invention provides a burner for low-heat value waste gas fuel, which can realize a combustion environment suitable for the low-heat value waste gas fuel, ensure that the air flow formed in the combustion environment is far less than the flow of the low-heat value waste gas fuel, and ensure the stable combustion of the low-heat value waste gas fuel even if combustion aids are not added.

The invention provides a burner for low-heating value waste gas fuel, which comprises a combustion chamber, a swirler, a fuel pipe and an air pipe, wherein the fuel pipe and the air pipe are communicated with the combustion chamber.

According to the burner for the low-heating-value waste gas fuel, the air pipe is sleeved in the fuel pipe and forms an annular passage with the fuel pipe, the swirler surrounds the annular passage, the air pipe is provided with a plurality of circumferentially distributed injection holes, and the air pipe is communicated with the annular passage through each injection hole.

According to the burner for the low-heating-value waste gas fuel, provided by the invention, each injection hole is close to the combustion chamber.

The burner for the low-heating-value waste gas fuel further comprises an auxiliary fuel pipe and an air flow channel, wherein the auxiliary fuel pipe is communicated with the combustion chamber, the auxiliary fuel pipe is sleeved on the periphery of the fuel pipe and forms an annular auxiliary channel with the fuel pipe, an auxiliary swirler is arranged in the annular auxiliary channel in a surrounding mode, and the annular auxiliary channel is communicated with the air flow channel through a plurality of auxiliary injection holes distributed in the circumferential direction.

According to the burner for low heating value exhaust gas fuel provided by the invention, the auxiliary injection hole is close to the injection outlet of the auxiliary fuel pipe.

According to the burner for the low heating value waste gas fuel provided by the invention, a plurality of auxiliary injection holes are arrayed in a plurality of rows along the length direction of the annular auxiliary channel and are circumferentially distributed between the annular auxiliary channel and the air flow channel.

According to the burner for the low-calorific-value waste gas fuel, the air flow channel is an annular channel integrally formed in the pipe wall of the auxiliary fuel pipe, and the auxiliary injection holes are integrally formed in the pipe wall of the auxiliary fuel pipe.

According to the burner for the low-heating-value waste gas fuel, provided by the invention, the fuel pipe is divided into a front-section fuel pipe and a rear-section fuel pipe, one end of the rear-section fuel pipe is communicated with the combustion chamber, and the other end of the rear-section fuel pipe is in threaded connection with the front-section fuel pipe; the air pipe divide into anterior segment air pipe and back end air pipe, back end air pipe one end is close to the jet outlet of fuel pipe, the other end with anterior segment air pipe threaded connection, a plurality of jet orifice circumference distributes the pipe wall of back end air pipe is close to the combustion chamber.

According to the burner for the low-heating-value waste gas fuel, provided by the invention, the plurality of injection holes are arrayed in a plurality of rows along the length direction of the rear-section air pipe and are circumferentially distributed on the rear-section air pipe.

According to the burner for the low-heating-value waste gas fuel, the spray holes distributed in the circumferential direction are alternately arranged in a large hole and a small hole.

The invention provides a burner for low-calorific value waste gas fuel, when low-calorific value waste gas fuel needs to be burnt, enough low-calorific value waste gas fuel jet flow is input into a fuel pipe, the low-calorific value waste gas fuel jet flow penetrates through a swirler to form swirl flow, the swirl flow formed low-calorific value waste gas fuel can form a backflow zone in a combustion chamber after entering the combustion chamber (the effect of the backflow zone is that combustion products flow back from downstream to upstream to form a stable ignition source), on the other hand, air serving as an oxidant enters the combustion chamber through an air pipe in a common jet flow mode to be mixed with a large amount of swirl diffused low-calorific value waste gas fuel, in order to ensure that the low-calorific value waste gas fuel has enough swirl strength after flowing through the swirler, the flow of the low-calorific value waste gas fuel can be greatly improved during input, so the low-calorific value waste gas fuel entering the combustion chamber and participating in mixing, the content of the combustible mixture is far greater than that of air (oxidant) in the combustion chamber, so that the air flow rate formed in the combustion environment is far less than the flow rate of the low-calorific-value waste gas fuel, namely, in the scheme of the invention, the circulation position of the air and the waste gas fuel in the prior art is replaced, the low-calorific-value waste gas fuel is enabled to generate rotational flow, the air (oxidant) is output by common jet flow and is mixed into the rotational flow of the waste gas fuel to form a combustible mixture with low air content, and therefore when the low-calorific-value combustible mixture is ignited, the generated flame is stable, stable combustion can be maintained without adding a combustion improver, and the low-calorific-value waste gas fuel is suitable for being processed. Therefore, the burner for the low-heat value waste gas fuel can realize a combustion environment suitable for the low-heat value waste gas fuel, ensure that the air flow formed in the combustion environment is far smaller than the flow of the low-heat value waste gas fuel, and ensure the stable combustion of the low-heat value waste gas fuel even if combustion improver is not added.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic view of a prior art burner configuration;

FIG. 2 is a schematic view of a prior art burner configuration;

FIG. 3 is a schematic view of a prior art burner configuration;

FIG. 4 is a plan view of the internal structure of the present invention;

FIG. 5 is a perspective view of the internal structure of the present invention;

FIG. 6 is a plan view of the internal structure of the present invention;

FIG. 7 is a perspective view of the internal structure of the present invention;

FIG. 8 is a partial block diagram of the present invention;

FIG. 9 is a partial structural cross-sectional view of the present invention;

FIG. 10 is a plan view of the internal structure of the present invention;

FIG. 11 is a perspective view of the internal structure of the present invention;

FIG. 12 is a plan view of the internal structure of the present invention;

FIG. 13 is a partial block diagram of the present invention;

FIG. 14 is a partial block diagram of the present invention;

fig. 15 is a partial structural view of the second embodiment of the present invention.

Reference numerals:

1 combustion chamber, 2 swirler, 3 fuel pipes, 4 air pipes, 5 annular channels, 6 injection holes, 7 auxiliary fuel pipes, 8 air flow channels, 9 annular auxiliary channels, 10 auxiliary swirler, 11 auxiliary injection holes, 31 front section fuel pipes, 32 rear section fuel pipes, 41 front section air pipes, 42 rear section air pipes.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

A burner for low calorific value exhaust gas fuel according to the present invention will be described with reference to fig. 4 and 5, which comprises a combustion chamber 1, a swirler 2, and a fuel pipe 3 and an air pipe 4 connected to the combustion chamber 1, wherein before combustion of exhaust gas, the exhaust gas fuel is introduced into the combustion chamber 1 through the fuel pipe 3, and air (oxidant) is introduced into the combustion chamber 1 through the air pipe 4, and further, the swirler 2 is installed in the fuel pipe 3, the exhaust gas fuel flowing in the fuel pipe 3 forms a swirling flow after passing through the swirler 2, the swirling exhaust gas fuel is diffused into the combustion chamber 1, and is sufficiently mixed with the air (oxidant) injected from the air pipe 4 to form a combustible mixture, and when an ignition device (not shown) in the combustion chamber 1 is turned on, the mixture is ignited and combusted.

When the low-calorific value waste gas fuel needs to be combusted, a low-calorific value waste gas fuel jet flow with enough flow is input into the fuel pipe 3, the low-calorific value waste gas fuel jet flow penetrates through the swirler 2 to form a rotational flow, a backflow zone is formed in the combustion chamber 1 after the rotational flow is formed, the rotational flow formed low-calorific value waste gas fuel enters the combustion chamber 1 (the backflow zone has the function of enabling combustion products to flow back from downstream to upstream to form a stable ignition source), on the other hand, air serving as an oxidant enters the combustion chamber 1 through the air pipe 4 in a common jet flow mode to be mixed with a large amount of rotational flow diffused low-calorific value waste gas fuel, in order to ensure that the low-calorific value waste gas fuel has enough rotational flow strength after flowing through the swirler 2, the flow of the low-calorific value waste gas fuel is greatly increased during inputting, so that the low-calorific value waste gas fuel entering the combustion chamber 1 and mixed with the low-calorific value waste gas fuel has the content far larger than the content of the air (oxidant) in the combustion chamber 1, the air flow rate formed in the combustion environment is ensured to be far smaller than the flow rate of the low-calorific-value waste gas fuel, that is, in the scheme of the invention, the circulation position of air and the waste gas fuel in the prior art is replaced, the low-calorific-value waste gas fuel generates a rotational flow, and the air (oxidant) is output in a common jet flow and is mixed into the rotational flow of the waste gas fuel to form a combustible mixture with low air content, so that when the low-calorific-value combustible mixture is ignited, the generated flame is stable, stable combustion can be maintained without adding a combustion supporter, and the low-calorific-value waste gas fuel is suitable for being treated. Therefore, the burner for the low-heat value waste gas fuel can realize a combustion environment suitable for the low-heat value waste gas fuel, ensure that the air flow formed in the combustion environment is far smaller than the flow of the low-heat value waste gas fuel, and ensure the stable combustion of the low-heat value waste gas fuel even if combustion improver is not added.

Further, as shown in fig. 6 to 9, the air tube 4 is inserted into the fuel tube 3 and forms an annular channel 5 with the fuel tube 3, the swirler 2 is annular and surrounds the annular channel 5, the air tube 4 is provided with a plurality of circumferentially distributed injection holes 6, and the air tube 4 is communicated with the annular channel 5 through each injection hole 6. In use, the exhaust gas fuel fed from the fuel pipe 3 will enter the combustion chamber 1 through the annular passage 5, while it will flow through the annular swirler 2 and form a swirling flow, since the air pipe 4 is inserted in the fuel pipe 3, in this embodiment, the air tube 4 is inserted into the center of the fuel tube 3, and since the air tube 4 is provided with a plurality of circumferentially distributed injection holes 6, therefore, the air jet flow input from the air pipe 4 can be simultaneously sprayed to the periphery in the annular channel 5 through the plurality of spray holes 6 distributed along the circumferential direction, the air jet flow can be mixed with the waste gas fuel in a swirling manner from a plurality of directions, this allows the exhaust fuel to be more uniformly mixed with air and to enter the combustion chamber 1 to form a diffuse combustible mixture a, the mixing effect is better, so that the mixture after mixing can be combusted more fully, the flame is more stable, and the combustion efficiency is higher.

Further, as shown in fig. 6 to 8, each injection hole 6 is close to the combustion chamber 1, and each injection hole 6 is closer to the gas outlet of the fuel pipe 3, so that the mixed combustible mixture can rapidly leave the fuel pipe 3 and enter the combustion chamber 1 for diffusion, thereby avoiding the risk of backfire, having higher reliability, and ensuring the continuous and stable operation of internal combustion.

In order to further increase the combustion amount of the combustor and enable the combustor to perform higher-load combustion operation, as shown in fig. 10 to 11, in this embodiment, an auxiliary fuel pipe 7 and an air flow passage 8 are further added to the combustor, the auxiliary fuel pipe 7 and the air flow passage 8 are both communicated with the combustion chamber 1, the auxiliary fuel pipe 7 is sleeved on the outer periphery of the fuel pipe 3 and forms an annular auxiliary channel 9 with the fuel pipe 3, an annular auxiliary swirler 10 is disposed around the annular auxiliary channel 9, and the annular auxiliary channel 9 is communicated with the air flow passage 8 through a plurality of circumferentially distributed auxiliary injection holes 11. The air jet that inputs from air runner 8 can be through each auxiliary jet hole 11 of circumference distribution simultaneously from spraying all around in annular auxiliary passage 9, the air jet can be from the mixing of the waste gas fuel whirl in a plurality of directions and the annular auxiliary passage 9, so alright can let waste gas fuel and air mix more evenly, enter into the combustible mixture B that forms partial premixing in combustion chamber 1 after the mixing, the effect of mixing is better, the mixture energy burning after making the mixing is more abundant, flame is more stable, and combustion efficiency is higher.

When the burner is in low-load combustion operation, namely the amount of the exhaust gas to be combusted is relatively small, the exhaust gas fuel and the air are respectively input only through the fuel pipe 3 and the air pipe 4; when a large amount of waste gas needs to be combusted, the combustor needs to achieve high-load combustion operation, after the auxiliary fuel pipe 7 and the air flow passage 8 are additionally arranged, the auxiliary fuel pipe 7 and the air pipe 4 can be used for jointly delivering gas, low-calorific-value waste gas fuel simultaneously enters the combustion chamber 1 through the fuel pipe 3 and the auxiliary fuel pipe 7, in the auxiliary fuel pipe 7, the waste gas fuel also forms rotational flow after flowing through the auxiliary swirler 10 and enters the combustion chamber 1 to form a backflow zone, air (oxidant) also can simultaneously pass through the air pipe 4 and the air flow passage 8 and is respectively injected in multiple directions through the injection hole 6 and the auxiliary injection hole 11, the air and the oxidant are respectively and fully mixed with the waste gas fuel and then enter the combustion chamber 1 for diffusion, and a diffused combustible mixture A and a partially premixed combustible mixture B are respectively formed in the combustion chamber 1, so that the waste gas treatment capacity of the combustor can be obviously improved, the burner is suitable for higher load combustion operation. In addition, since the fuel pipe 3 is fitted to the air pipe 4 and the auxiliary fuel pipe 7 is fitted to the fuel pipe 3, the air pipe 4, the auxiliary fuel pipe 7, and the air flow passage 8 can be made independent of each other, and the flow rates thereof can be controlled individually, which is advantageous for improving the accuracy of the air flow adjustment of the combustor.

Furthermore, the auxiliary injection hole 11 is close to the injection outlet of the auxiliary fuel pipe 7, so that the mixed combustible mixture can rapidly leave the auxiliary fuel pipe 7 and enter the combustion chamber 1 for diffusion, the risk of backfire is avoided, the reliability is higher, and the continuous and stable operation of internal combustion is ensured.

Specifically, the auxiliary injection holes 11 are arranged in a plurality of rows along the length direction of the annular auxiliary channel 9 and are circumferentially distributed between the annular auxiliary channel 9 and the air flow channel 8, that is, the circumferentially distributed auxiliary injection holes 11 are arranged in a plurality of rows, so that the exhaust gas fuel in the annular auxiliary channel 9 and the air in the air flow channel 8 can be mixed for a longer distance, the mixing is more uniform, the mixed mixture can be combusted more fully, the flame is more stable, and the combustion efficiency is higher.

Specifically, as shown in fig. 10 and 11, the air flow passage 8 is an annular passage integrally formed in the tube wall of the auxiliary fuel tube 7, and the plurality of auxiliary injection holes 11 are integrally formed in the tube wall of the auxiliary fuel tube 7, so that the air flow passage 8, the auxiliary fuel tube 7, and the auxiliary injection holes 11 can be integrally manufactured, the production cost can be reduced, the requirement for the mounting accuracy can be reduced, and the mounting of the burner can be simplified.

More specifically, as shown in fig. 12, the fuel pipes 3 are divided into a front stage fuel pipe 31 and a rear stage fuel pipe 32, one end of the rear stage fuel pipe 32 is connected to the combustion chamber 1, and the other end is screwed to the front stage fuel pipe 31; the air tube 4 is divided into a front-section air tube 41 and a rear-section air tube 42, one end of the rear-section air tube 42 is close to the injection outlet of the fuel tube 3, the other end of the rear-section air tube 42 is in threaded connection with the front-section air tube 41, and a plurality of injection holes 6 are circumferentially distributed on the tube wall of the rear-section air tube 42 and are close to the combustion chamber 1. Through the structure, the extension of the fuel pipe 3 and the air pipe 4 can be realized according to actual requirements, and the assembly is more compact.

Alternatively, as shown in fig. 13, the respective injection holes 6 are arranged in several rows along the length direction of the rear-stage air pipe 42 and circumferentially distributed on the rear-stage air pipe 42. That is, the plurality of rows of the injection holes 6 distributed in the circumferential direction can mix the exhaust gas fuel in the annular passage 5 with the air in the air pipe 4 for a longer distance, so that the mixing is more uniform, the mixed mixture can be combusted more sufficiently, the flame is more stable, and the combustion efficiency is higher.

Alternatively, as shown in fig. 14, the circumferentially distributed injection holes 6 are arranged in a large-hole and small-hole alternating manner, and this structure can further effectively improve the mixing effect of the exhaust gas fuel and the air, and the mixing is further more uniform.

Example two

The present embodiment is similar to the first embodiment except that, as shown in fig. 15, the injection hole 6 at the end of the rear air pipe 42 is a through hole directly connected to the inside of the rear air pipe 42, which can restrict the mixing of the exhaust gas fuel and the air, and can be selected appropriately according to the type, the calorific value, the density, the flow rate, etc. of the exhaust gas in use, so as to achieve the desired combustion effect.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A burner for low heating value waste gas fuel, comprising a combustion chamber (1), a swirler (2) and a fuel pipe (3) and an air pipe (4) communicated with the combustion chamber (1), characterized in that the swirler (2) is arranged in the fuel pipe (3) to promote the waste gas fuel flowing in the fuel pipe (3) to form a swirling flow and then enter the combustion chamber (1) to form a backflow zone and be mixed with air jetted from the air pipe (4).

2. Burner for low heating value exhaust gas fuel according to claim 1, characterized in that said air pipe (4) is inserted inside said fuel pipe (3) and forms an annular channel (5) with the fuel pipe (3), said swirler (2) is surrounded inside said annular channel (5), said air pipe (4) is opened with a plurality of circumferentially distributed injection holes (6), the air pipe (4) is connected to said annular channel (5) through each injection hole (6).

3. Burner for low heating value exhaust gas fuel according to claim 2, characterized in that each of said injection holes (6) is close to said combustion chamber (1).

4. The burner for low heating value waste gas fuel according to claim 2, further comprising an auxiliary fuel pipe (7) and an air flow passage (8) communicated with the combustion chamber (1), wherein the auxiliary fuel pipe (7) is sleeved on the outer periphery of the fuel pipe (3) and forms an annular auxiliary channel (9) with the fuel pipe (3), an auxiliary swirler (10) is arranged around the annular auxiliary channel (9), and the annular auxiliary channel (9) is communicated with the air flow passage (8) through a plurality of circumferentially distributed auxiliary injection holes (11).

5. Burner for low heating value exhaust gas fuel according to claim 4, characterized in that the auxiliary injection hole (11) is close to the injection outlet of the auxiliary fuel pipe (7).

6. Burner for low heating value exhaust gas fuel according to claim 5, characterized in that several of said auxiliary injection holes (11) are arranged in several rows along the length direction of the annular auxiliary channel (9) and are circumferentially distributed between the annular auxiliary channel (9) and the air flow channel (8).

7. The burner for low heating value exhaust gas fuel according to claim 4, wherein the air flow passage (8) is an annular passage integrally formed in a tube wall of the auxiliary fuel tube (7), and a plurality of the auxiliary injection holes (11) are integrally formed in the tube wall of the auxiliary fuel tube (7).

8. The burner for low heating value exhaust gas fuel according to any one of claims 2 to 7, wherein the fuel pipe (3) is divided into a front section fuel pipe (31) and a rear section fuel pipe (32), one end of the rear section fuel pipe (32) is communicated with the combustion chamber (1), and the other end is in threaded connection with the front section fuel pipe (31); air pipe (4) divide into anterior segment air pipe (41) and back end air pipe (42), back end air pipe (42) one end is close the jet outlet of fuel pipe (3), the other end with anterior segment air pipe (41) threaded connection, a plurality of jet orifice (6) circumference distributes and is in the pipe wall of back end air pipe (42) is close combustion chamber (1).

9. The burner for low heating value exhaust gas fuel according to claim 8, wherein a plurality of the injection holes (6) are arranged in a plurality of rows along the length direction of the rear-stage air pipe (42) and circumferentially distributed on the rear-stage air pipe (42).

10. Burner for low heating value exhaust gas fuel according to claim 9, characterized in that each circumferentially distributed injection hole (6) is arranged with a large and a small hole alternately.