CN219433258U - Dual cycle low nitrogen combustor - Google Patents

Abstract

The utility model relates to the technical field of combustors, and discloses a double-circulation low-nitrogen combustor which comprises a combustion head: the combustion head comprises an air supply channel, a first fuel supply system and a second fuel supply system; the air supply channel comprises an air supply chamber and an air outlet channel; the diameter of one side of the air supply chamber far away from the air outlet channel is larger than the diameter of one side of the air supply chamber close to the air outlet channel; an inner cylinder is sleeved in the air outlet channel; the outer cylinder is sleeved on the periphery of the tail end of the air outlet channel; a first fuel supply system passing through the inner barrel; the first fuel supply system comprises a main fuel pipe and a spray head, and the spray head is arranged at one end of the main fuel pipe far away from the air supply cavity; the inner cylinder, the outer cylinder and the first fuel supply system are arranged in parallel; the second fuel supply system is arranged at the periphery of the air supply chamber and is close to the air outlet channel. Before combustion, the burner respectively completes mixing of air and inert combustion products in smoke and mixing of fuel and inert combustion products in smoke, so that the peak value of combustion flame can be reduced, and the emission of nitrogen oxides can be effectively reduced.

Description

Dual cycle low nitrogen combustor

Technical Field

The utility model belongs to the technical field of the combustor, concretely relates to dual cycle low nitrogen combustor.

Background

For combustion of gas, the mechanism of NOx generation is mainly thermal, i.e. when the flame temperature is high enough, the covalent bond of N2 is broken to give free N ions, which combine with oxygen atoms to form NOx. Low nitrogen burners are one technology developed for the environmental problem of generating large amounts of nitrogen oxides (NOx) in combustion processes. NOx is one of the main components of air pollution, and is a hazard to the atmospheric environment and human health. In the combustion process, nitrogen and oxygen in the air react to generate NOx under high temperature and high pressure conditions, so that the generation of NOx can be reduced by reducing the temperature and the pressure in the combustion process. The low-nitrogen burner reduces the combustion temperature and pressure by optimizing the structure of the combustion chamber, adjusting the parameters of the combustion process and the like, thereby achieving the purpose of reducing the generation of NOx. The low-nitrogen burner technology is widely applied to the fields of industrial combustion, electric power, petrochemical industry and the like, and becomes one of important technologies in the field of environmental protection.

The utility model adopts the method that the local low-pressure area is manufactured through the flow fields in the burner and the combustion chamber, and the fuel gas and partial inert combustion products are mixed together and the air and partial inert combustion products are mixed before combustion occurs, so that the peak temperature of the combustion area is greatly reduced, and the generation of NOx is inhibited.

Disclosure of Invention

The purpose of the utility model is that: aims at providing a double-circulation low-nitrogen burner which is used for solving the problems of how to further reduce the emission of nitrogen oxides of a boiler and avoiding the emission of atmospheric pollution in the prior art.

In order to achieve the technical purpose, the technical scheme adopted by the novel device is as follows:

a dual cycle low nitrogen burner for use in a combustion chamber, comprising a burner head:

the combustion head is fixedly connected with the combustion chamber and comprises an air supply channel, a first fuel supply system and a second fuel supply system; the air supply channel comprises an air supply chamber and an air outlet channel; the diameter of one side of the air supply cavity far away from the air outlet channel is larger than the diameter of one side of the air supply cavity near the air outlet channel; an inner cylinder is sleeved in the air outlet channel; an outer cylinder is sleeved on the periphery of the tail end of the air outlet channel; the first fuel supply system passes through the inner cylinder; the first fuel supply system comprises a main fuel pipe and a spray head, and the spray head is arranged at one end of the main fuel pipe far away from the air supply cavity; the inner cylinder, the outer cylinder and the first fuel supply system are arranged in parallel; the second fuel supply system is arranged at the periphery of the air supply chamber and close to the air outlet channel.

Further, the shape of the air outlet channel is tapered; the aperture of one end of the air outlet channel, which is close to the air supply chamber, is larger than the aperture of one end of the air outlet channel, which is far away from the air supply chamber.

Further, the second fuel supply system includes a gas collection bag, a plurality of nozzles, and a plurality of nozzles; the nozzle is arranged at one end of the spray pipe far away from the air supply cavity; a plurality of nozzles are surrounded outside the outer cylinder.

Further, an injection pipe is sleeved outside the nozzle; the aperture of the injection pipe is larger than the aperture of the nozzle.

Further, a swirl disk is sleeved outside the spray head; the cyclone disc is positioned at the outlet of the inner cylinder; the rotational flow disc comprises a disc body, a rotary vane, a guard ring and a ring, wherein the ring is connected with the disc body and divides the disc body into an inner area and an outer area, a plurality of through holes are formed in the inner area of the disc body, and a plurality of rotary vanes are arranged in the outer area of the disc body; a plurality of branch pipes are arranged around the spray head; a plurality of young pipes are communicated with the branch pipes; the young pipe passes through the cyclone disc; a plurality of air holes are formed in the circumferential direction of the spray head; the air holes are positioned above the cyclone disc.

Further, the number of the young pipes on each branch pipe is two; the young pipe is arranged in parallel with the inner cylinder.

Further, a mounting plate is arranged at the joint of the combustion head and the combustion chamber; the mounting plate is closely attached to the combustion chamber.

Compared with the prior art, the utility model has the beneficial effects that:

1. before combustion, the mixing of air and inert combustion products in the flue gas and the mixing of fuel and inert combustion products in the flue gas are respectively completed, so that the peak value of combustion flame can be greatly reduced, the emission of nitrogen oxides can be effectively reduced, and compared with the flue gas external circulation technology, the performance of the burner in the aspects of flame length, regulation ratio and stability can not be sacrificed.

2. The middle flame stabilizing area adopts a mode that rotational flow wind and fuel gas are close to right-angle cross jet flow, so that the mixing of wind and fuel gas is quickened, the stability of combustion is ensured, meanwhile, the effective low flame peak value is reduced, and the generation of nitrogen oxides is effectively inhibited.

3. The present utility model may provide a turndown ratio of 10:1 to 20:1.

Drawings

The utility model can be further illustrated by means of non-limiting examples given in the accompanying drawings;

FIG. 1 is a cross-sectional view of a dual cycle low nitrogen combustor of the present utility model;

FIG. 2 is a top view of a dual cycle low nitrogen burner of the present utility model;

FIG. 3 is a perspective view of a dual cycle low nitrogen burner of the present utility model;

FIG. 4 is a flow field schematic of a dual cycle low nitrogen combustor of the present utility model;

FIG. 5 is a partial schematic view of a dual cycle low nitrogen combustor according to the present utility model;

FIG. 6 is a schematic view of a swirl disk in a dual cycle low nitrogen combustor according to the present utility model;

FIG. 7 is a schematic diagram of the positional relationship between the swirl disk and the nozzle in a dual cycle low nitrogen burner of the present utility model.

The main reference numerals are as follows:

a combustion head 100, an air supply duct 110, an air supply chamber 111, and an air outlet duct 112;

a first fuel supply system 120, a main fuel pipe 121, a nozzle 122, a branch pipe 122-1, a juvenile pipe 122-2, and an air hole 122-3;

swirl disk 123, disk body 123-1, rotary vane 123-2, retainer 123-3, and ring 123-4;

a second fuel supply system 130, a gas collecting bag 131, a spray pipe 132, a nozzle 133 and an ejector pipe 134;

the flue gas recirculation system comprises an outer cylinder 140, an inner cylinder 150, a flue gas recirculation mixing channel 160, a combustion chamber 170, a furnace body 180 and a mounting plate 190.

Detailed Description

The present utility model will be described in detail below with reference to the drawings and the specific embodiments, wherein like or similar parts are designated by the same reference numerals throughout the drawings or the description, and implementations not shown or described in the drawings are in a form well known to those of ordinary skill in the art. In addition, directional terms such as "upper", "lower", "top", "bottom", "left", "right", "front", "rear", etc. in the embodiments are merely directions with reference to the drawings, and are not intended to limit the scope of the present utility model.

As shown in fig. 1-7, a dual cycle low nitrogen burner is applied to a combustion chamber 170, the combustion chamber 170 being generally disposed within a furnace body 180, including a burner head 100:

the combustion head 100 is fixedly connected with the combustion chamber 170, and the combustion head 100 comprises an air supply duct 110, a first fuel supply system 120 and a second fuel supply system 130; the air supply duct 110 is installed in a protruding manner into the combustion chamber 170; the air supply duct 110 includes an air supply chamber 111 and an air outlet duct 112; the cross section of the air supply chamber 111 is similar to a trapezoid, and the length of the upper bottom surface is longer than that of the lower bottom surface; specifically, the diameter of the side of the air supply chamber 111 away from the air outlet duct 112 is larger than the diameter of the side of the air supply chamber 111 close to the air outlet duct 112; an inner cylinder 150 is sleeved in the air outlet duct 112; the annular channel between the inner cylinder 150 and the air outlet duct 112 forms an air nozzle 133; most of the air in the air supply duct 110 flows out of the air nozzle 133, and a small part of the air flows out of the inner cylinder 150; an outer cylinder 140 is sleeved on the periphery of the tail end of the air outlet duct 112; the passage between the outer cylinder 140 and the inner cylinder 150 forms a flue gas reflux mixing passage 160; the first fuel supply 120 passes through the inner barrel 150; for supplying fuel to the inner flame and the middle flame; the first fuel supply system 120 includes a main fuel pipe and a nozzle 122, and the nozzle 122 is disposed at an end of the main fuel pipe away from the air supply chamber 111; the inner cylinder 150, the outer cylinder 140, and the first fuel supply system 120 are disposed in parallel; the second fuel supply system 130 is disposed at the periphery of the air supply chamber 111 near the air outlet duct 112, for supplying fuel to the main flame.

In operation, combustion air is first supplied through the supply duct 110, most of the combustion air flows through the air nozzles 133 to the combustion chamber 170, and a small portion of the combustion air enters the inner barrel 150 to the combustion chamber 170. Since the aperture of the air supply chamber 111 from the air supply duct 110 to the channel of the combustion chamber 170 is reduced, the flow velocity of the combustion air is increased when passing through the air nozzle 133, and then a low pressure area is formed in the flue gas recirculation mixing channel 160 to suck the flue gas in the combustion chamber 170, and the combustion air in the flue gas recirculation mixing channel 160 and the inert combustion products are initially mixed in the flue gas recirculation mixing channel 160. A small portion of the combustion air passes through the inner barrel 150 to supply the air required for combustion to the central combustion zone. The combustion air mixed with the fuel provided by the second fuel supply system 130 in the flue gas backflow mixing channel 160 forms a peripheral combustion zone, and the peak value of the combustion flame can be greatly reduced due to the mixing of the fuel and the inert combustion products in the flue gas, so that the emission of nitrogen oxides is effectively reduced. In addition, the combustion air in the central combustion area is less, the oxygen content is lower, the generation of nitrogen oxides is further reduced, and meanwhile, an intermediate flame stabilizing area is formed; and stable flame is provided for the peripheral combustion zone, heat is continuously transferred between the two combustion zones, and the combustion stability is further improved.

Compared with the prior art, the burner adopts double-circulation air supply, and the internal combustion circulation and the external combustion circulation lead the combustion efficiency to be higher, and simultaneously reduce the emission of harmful gases such as NOx and the like. Meanwhile, because the internal combustion circulation and the external combustion circulation are adopted, the combustion is more stable, and the possibility of flame instability is reduced. In addition, the burner adopts a dual-fuel supply system, and can respectively adjust the air supply proportion of the inner flame, the middle flame and the outer flame according to the needs, thereby being suitable for different combustion requirements. Finally, the burner has a relatively simple structure, and adopts the trapezoidal air supply chamber 111 and the inner cylinder body and the outer cylinder body, so that the burner occupies small space and is convenient to install and maintain.

In some embodiments, the outlet duct 112 is tapered in shape; the aperture of the end of the air outlet duct 112 near the air supply chamber 111 is larger than the aperture of the end of the air outlet duct 112 far away from the air supply chamber 111. The tapered shape of the outlet duct 112 may accelerate the airflow as it passes through the outlet duct 112, thereby increasing the speed and pressure of the airflow, facilitating an increase in the air flow rate within the combustion chamber 170, and enhancing the intensity and efficiency of combustion. The design of the tapered outlet duct 112 allows for more thorough mixing of fuel and air, thereby allowing for more uniform and complete combustion, reducing unburned emissions, and improving combustion efficiency. In addition, by controlling the shape and pore size of the air outlet duct 112, the ratio and speed of air and fuel can be adjusted, thereby controlling the stability of the flame and avoiding instability or excessive severity of the flame.

In some embodiments, the second fuel supply system 130 includes a manifold 131, a plurality of nozzles 132, and a plurality of nozzles 133; the nozzle 133 is disposed at an end of the nozzle 132 remote from the air supply chamber 111; a plurality of the nozzles 133 are surrounded outside the outer tub 140. The adoption of the gas collecting bag 131 can improve the stability and the continuity of fuel supply, and meanwhile, the arrangement of a plurality of spray pipes 132 and a plurality of spray nozzles 133 can increase the fuel supply quantity, so that the combustion is more sufficient and efficient. The arrangement of the plurality of nozzles 133 can fully disperse the fuel, form more spray points and fully mix the fuel with the air, thereby improving the mixing effect of the fuel and enabling the combustion to be more sufficient and efficient. The circumferential arrangement of the plurality of nozzles 133 may provide for a more even distribution of fuel within the combustion chamber 170, thereby enhancing flame stability and avoiding flame instability or excessive severity.

In some embodiments, the nozzle 133 is sheathed with an ejector tube 134; the ejector tube 134 has a larger aperture than the nozzle 133. Because the nozzle 133 sprays high-speed fuel, a low-pressure area is formed in the injection pipe 134 to suck the smoke in the combustion chamber 170, the fuel sprayed by the nozzle 133 and the smoke are premixed before combustion, and the generation of nitrogen oxides is further reduced.

In some embodiments, the nozzle 122 is sleeved with a swirl disk 123; the swirl disk 123 is positioned at the outlet of the inner cylinder 150; the rotational flow disc 123 comprises a disc body 123-1, a rotational blade 123-2, a retainer 123-3 and a ring 123-4, wherein the ring 123-4 is connected with the disc body 123-1 and divides the disc body 123-1 into an inner area and an outer area, the inner area of the disc body 123-1 is provided with a plurality of through holes, and the outer area of the disc body 123-1 is provided with a plurality of rotational blades 123-2; in this embodiment, 6 rotary blades 123-2 are preferably provided in the outer region of the disc 123-1; this increases the rotational velocity of the gas flow within the combustion chamber 170, further mixing and combusting the mixture to improve combustion efficiency and reduce nitrogen oxide emissions. The swirl vane 123-2 may generate a swirl flow to rotate the air flow and create strong turbulence to enhance the mixing and combustion process. In addition, the through-hole structure of the outer region of the disk 123-1 can also increase the turbulence degree of the air flow, promoting mixing and combustion. A plurality of branch pipes 122-1 are arranged around the spray head 122; the branch pipe 122-1 is communicated with a plurality of young pipes 122-2; the young pipe 122-2 passes through the cyclone disc 123; a plurality of air holes 122-3 are formed in the circumferential direction of the spray head 122; the air holes 122-3 are located above the swirl disk 123. The primary purpose of the swirl disk 123 is to increase the degree of mixing of fuel and air, thereby providing more complete combustion and higher thermal efficiency. As fuel is ejected from the nozzle 122, it enters the inner region of the swirl disk 123 through the branch pipe 122-1 and the juvenile pipe 122-2, and then passes through the plurality of through holes and the swirl plate 123-2 of the swirl disk 123, generating rotation and vortex. This movement mixes the fuel and air together and ejects the mixture outwardly, causing it to form a stable flame kernel in the combustion chamber 170. At the same time, the air holes 122-3 around the nozzle tip 122 may further increase the degree of mixing, introducing air into the swirl disk 123, thereby better mixing the fuel and air. Thus, more sufficient combustion can be realized, pollutant emission is reduced, and combustion efficiency is improved.

In operation, fuel gas is combusted and supplied to the central region by the first fuel supply system 120: a small amount of fuel gas is ejected out through the through holes of the nozzle 122 and mixed with combustion-supporting air passing through the holes in the inner area of the cyclone disc 123 to form internal flame; a part of fuel gas is ejected out of a plurality of branch pipes 122-1 and young pipes 122-2 communicated with each other through a nozzle 122 and is mixed with combustion supporting air passing through a rotary vane 123-2 in the outer area of the flame stabilizing disc to form middle flame; the air flowing out between the inner cylinder 150 and the cyclone disc 123 and the fuel gas emitted by the spray head 122 are in a cross jet flow at an angle which is nearly vertical, so that the mixing speed is high, and the combustion temperature is reduced; and meanwhile, the swirl disk 123 is beneficial to forming a swirl zone so as to ensure the stability of the flame in the central zone.

The second fuel supply system 130 injects fuel gas from the nozzle 133 toward the combustion chamber 170, and the inert combustion products in the furnace are entrained and mixed, and further mixed with the mixture flowing out of the outer cylinder 140 before entering the main combustion zone, and burned.

In some embodiments, the number of juvenile tubes 122-2 on each of the leg tubes 122-1 is two; the juvenile tube 122-2 is disposed parallel to the inner barrel 150. This arrangement can increase the number of fuel spouts and improve the combustion efficiency and thermal efficiency of the burner. By arranging the juvenile tube 122-2 in parallel with the inner tube 150, the turbulence generated during fuel injection can be reduced, so that the fuel can be more uniformly mixed in the air, and the combustion efficiency and the thermal efficiency can be further improved.

In some embodiments, a mounting plate 190 is provided at the junction of the combustion head 100 and the combustion chamber 170; the mounting plate 190 is in close proximity to the combustion chamber 170. The mounting plate 190 is tightly attached to the combustion chamber 170, so that combustion gas in the combustion chamber 170 can be effectively prevented from leaking, and the safety and effectiveness of combustion are ensured. Meanwhile, the mounting plate 190 can conveniently connect the combustion head 100 with the combustion chamber 170, so that the stability and reliability of the combustion head 100 are ensured.

The double-circulation low-nitrogen combustor provided by the utility model is described in detail above. The description of the specific embodiments is only intended to aid in understanding the method of the present utility model and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the utility model can be made without departing from the principles of the utility model and these modifications and adaptations are intended to be within the scope of the utility model as defined in the following claims.

Claims (7)

1. A dual cycle low nitrogen burner for use in a combustion chamber (170) comprising a burner head (100), characterized in that:

the combustion head (100) is fixedly connected with the combustion chamber (170), and the combustion head (100) comprises an air supply channel (110), a first fuel supply system (120) and a second fuel supply system (130); the air supply duct (110) comprises an air supply chamber (111) and an air outlet duct (112); the diameter of one side of the air supply chamber (111) far away from the air outlet channel (112) is larger than the diameter of one side of the air supply chamber (111) near the air outlet channel (112); an inner cylinder (150) is sleeved in the air outlet channel (112); an outer cylinder (140) is sleeved on the periphery of the tail end of the air outlet channel (112); the first fuel supply system (120) passes through the inner barrel (150); the first fuel supply system (120) comprises a main fuel pipe (121) and a spray head (122), wherein the spray head (122) is arranged at one end of the main fuel pipe (121) far away from the air supply cavity (111); the inner cylinder (150), the outer cylinder (140) and the first fuel supply system (120) are arranged in parallel; the second fuel supply system (130) is arranged at the periphery of the air supply chamber (111) and near the air outlet channel (112).

2. A dual cycle low nitrogen burner as defined in claim 1, wherein:

the shape of the air outlet duct (112) is in a tapered shape; the aperture of the air outlet channel (112) close to one end of the air supply chamber (111) is larger than the aperture of the air outlet channel (112) far away from one end of the air supply chamber (111).

3. A dual cycle low nitrogen burner as defined in claim 2, wherein:

the second fuel supply system (130) comprises a gas collection bag (131), a plurality of spray pipes (132) and a plurality of spray nozzles (133); the nozzle (133) is arranged at one end of the spray pipe (132) far away from the air supply chamber (111); a plurality of the nozzles (133) are surrounded outside the outer cylinder (140).

4. A dual cycle low nitrogen burner as claimed in claim 3, wherein:

an injection pipe (134) is sleeved outside the nozzle (133); the aperture of the injection pipe (134) is larger than the aperture of the nozzle (133).

5. A dual cycle low nitrogen burner as defined in claim 4, wherein:

a swirl disk (123) is sleeved outside the spray head (122); the swirl disk (123) is positioned at the outlet of the inner cylinder (150); the rotational flow disc (123) comprises a disc body (123-1), a rotary vane (123-2), a retainer (123-3) and a ring (123-4), wherein the ring (123-4) is connected with the disc body (123-1) and divides the disc body (123-1) into an inner area and an outer area, a plurality of through holes are formed in the inner area of the disc body (123-1), and a plurality of rotary vanes (123-2) are arranged in the outer area of the disc body (123-1); a plurality of branch pipes (122-1) are arranged around the spray head (122); a plurality of young pipes (122-2) are communicated with the branch pipes (122-1); the young pipe (122-2) passes through the cyclone disc (123); a plurality of air holes (122-3) are formed in the circumferential direction of the spray head (122); the air holes (122-3) are positioned above the cyclone disc (123).

6. A dual cycle low nitrogen burner as defined in claim 5, wherein:

the number of the young pipes (122-2) on each branch pipe (122-1) is two; the young pipe (122-2) is arranged in parallel with the inner cylinder (150).

7. A dual cycle low nitrogen burner as defined in claim 6, wherein:

a mounting plate (190) is arranged at the joint of the combustion head (100) and the combustion chamber (170); the mounting plate (190) is in close contact with the combustion chamber (170).