CN114110580A

CN114110580A - Low-nitrogen combustor

Info

Publication number: CN114110580A
Application number: CN202111403677.6A
Authority: CN
Inventors: 黄显模
Original assignee: Beijing Suntouch Thermprocess Equipment Co ltd
Current assignee: Beijing Suntouch Thermprocess Equipment Co ltd
Priority date: 2018-04-25
Filing date: 2018-04-25
Publication date: 2022-03-01
Also published as: CN108613181A

Abstract

The invention discloses a low-nitrogen burner, which relates to the technical field of gas burners of industrial boilers and industrial furnaces and comprises a shell, a primary gas pipe, a secondary gas pipe and an air grading fluid director, wherein one end of the shell is provided with a gas inlet and an air inlet, and the other end of the shell is provided with a combustion chamber; the primary gas pipe and the secondary gas pipe are both arranged in the shell, one end of the primary gas pipe is communicated with the gas inlet, one end of the secondary gas pipe is communicated with one end of the primary gas pipe close to the gas inlet, and the other end of the secondary gas pipe faces the combustion chamber; the air classification fluid director is arranged in the shell, an air channel is formed between the outer wall of the air classification fluid director and the inner wall of the shell, one port of the air classification fluid director is communicated with one end, far away from the fuel gas inlet, of the primary fuel gas pipe, and the other port of the air classification fluid director faces the combustion chamber. The low-nitrogen combustor provided by the invention reduces the emission of nitrogen oxides.

Description

Low-nitrogen combustor

The application is a divisional application of an invention patent with a parent name of 'a low-nitrogen burner'; the parent application has the application number: CN 201810377648.9; the application date of the parent application is as follows: 2018.04.25.

Technical Field

The invention relates to the technical field of industrial boilers and industrial furnace gas burners, in particular to a low-nitrogen burner.

Background

Nitrogen oxides in air, e.g. NO, NO₂，N₂O₃，N₂O₅Etc. are collectively referred to as NO_xTypically from the combustion of fuel. NO produced by industrial combustion devices_xMainly comprises two parts: n in combustion air₂High temperature NO produced by oxidation_xAnd fuel NO generated from nitrogen oxides in the fuel_x；

Fuel NO_xGeneration of (1): HCN, NH in industrial fuels (oil, coal, natural gas, etc.)₃N contained in the iso-nitrides is called fuel nitrogen, and NO generated during combustion of the fuel nitrogen_xReferred to as fuel NO_xFuel NO_xThe generation of (c) is related to the quality of the fuel.

High temperature NO_xIs formed by N in combustion air during combustion₂The products of the oxidation reaction at high temperatures are related to the furnace temperature and the flame temperature. Since the temperature of the hearth is not changeable due to the hot working process, the structural design and the combustion technology of the burner are to reduce high-temperature NO_xIs a key factor of (1).

An existing common burner is shown in fig. 1 and comprises a shell 2, a gas inlet 1 and an air inlet 4 are formed in one end of the shell 2, a combustion chamber 9 is formed in the other end of the shell, a gas pipe 11 is installed in the shell, one end of the gas pipe 11 is communicated with the gas inlet, and the other end of the gas pipe is communicated with the combustion chamber. When the gas burner is used, gas is introduced through the gas inlet, air is introduced through the air inlet, the gas is mixed with the entering air at the outlet of the gas pipe through the gas pipe and is discharged through the combustion chamber, and in the process, mixed gas is ignited by using tools such as an igniter and the like, so that the gas burner can be used.

The burner with the structure has large discharge of nitrogen oxides and cannot meet the requirements of people, so the improvement of the structure and the combustion technology of the burner is urgent.

Disclosure of Invention

The present invention is directed to a low-nitrogen burner, which solves the above problems of the prior art and can reduce the emission of nitrogen oxides.

In order to achieve the purpose, the invention provides the following scheme:

the present invention provides a low-nitrogen burner, comprising: the gas-fired boiler comprises a shell, a primary gas pipe, a secondary gas pipe and an air grading fluid director, wherein one end of the shell is provided with a gas inlet and an air inlet, and the other end of the shell is provided with a combustion chamber; the primary gas pipe and the secondary gas pipe are both arranged in the shell, one end of the primary gas pipe is communicated with the gas inlet, one end of the secondary gas pipe is communicated with one end, close to the gas inlet, of the primary gas pipe, and the other end of the secondary gas pipe faces the combustion chamber; the air classification fluid director is arranged in the shell, an air channel is formed between the outer wall of the air classification fluid director and the inner wall of the shell, one port of the air classification fluid director is communicated with one end, far away from the fuel gas inlet, of the first-stage fuel gas pipe, and the other port of the air classification fluid director faces the combustion chamber.

Preferably, the air classification fluid director comprises a hollow cylinder and a swirl plate, the cylinder is connected with the swirl plate, the primary gas pipe is connected with the cylinder and communicated with the inside of the cylinder, one end of an outlet of the swirl plate is communicated with the inside of the cylinder, and the other end of the outlet of the swirl plate is communicated with the combustion chamber; a first through hole communicated with the interior of the cylinder is formed in the cylinder, and a second through hole communicated with the combustion chamber is formed in the circumferential direction of the outer edge of the spinning disk; the air inlet communicates with the interior of the cylinder through the first through hole and communicates with the combustion chamber through the second through hole.

Preferably, the barrel is provided with the arch in the circumferencial direction, first through-hole is a plurality of, wherein, partly first through-hole is located the arch is just right one side of gas import, and with the axis of barrel has the contained angle, another part first through-hole is located the barrel with the connection face that the one-level gas union coupling is connected, the barrel with the one-level gas pipe coaxial line sets up.

Preferably, the primary gas pipe extends into the barrel, and a gas hole is formed in the side wall of the primary gas pipe extending into the barrel.

Preferably, the air classification fluid director comprises a first-stage flow guide pipe, a second-stage flow guide pipe, a third-stage flow guide pipe and a swirl piece, wherein the first-stage flow guide pipe, the second-stage flow guide pipe, the third-stage flow guide pipe and the swirl piece are sequentially connected into a whole and are communicated with each other, one end, far away from the second-stage flow guide pipe, of the first-stage flow guide pipe is provided with a gas through hole and a first-stage air through hole and is connected with the first-stage gas pipe, an included angle is formed between the axis of the first-stage air through hole and the axis of the air classification fluid director, the gas through hole is communicated with the first-stage gas pipe, one end of an outlet of the swirl piece is communicated with the inside of the third-stage flow guide pipe, and the other end of the outlet of the swirl piece is communicated with the combustion chamber; the first-stage draft tube is provided with a first inclined plane which inclines inwards, the outer surface of the second-stage draft tube is provided with a second inclined plane which inclines outwards, the first inclined plane is connected with the second inclined plane, a secondary air through hole is arranged at the top of the second inclined plane, the axis of the secondary air through hole and the axis of the fluid director form an included angle, the inner side of the secondary flow guide pipe is provided with a third inclined plane which inclines inwards, the outer surface of the third-stage draft tube is provided with a fourth inclined surface, the second-stage draft tube is connected with the fourth inclined surface, a third-stage air through hole is arranged at the bottom of the fourth inclined plane, an included angle is formed between the axis of the third-stage air through hole and the axis of the fluid director, a fifth inclined surface which inclines inwards is arranged on the inner side of the third-level flow guide pipe, and an outlet of the spinning disk is connected with the fifth inclined surface; the outward flange of spinning disk be provided with the second through-hole of combustion chamber intercommunication.

Preferably, the combustion chamber is enclosed by a cylindrical shell and a hollow truncated cone-shaped shell, the cylindrical shell and the truncated cone-shaped shell are integrally arranged, the bottom surface with the large area of the truncated cone-shaped shell is connected with the cylindrical shell, and the bottom surface with the small area of the truncated cone-shaped shell is connected with the combustion chamber.

Preferably, an igniter is mounted on the housing; the firing end of the igniter is located within the barrel.

Preferably, the ignition end of the igniter is positioned on one side of the barrel body close to the primary gas pipe.

Preferably, one end of the secondary gas pipe, which is far away from the primary gas pipe, penetrates through the spinning disk to be communicated with the combustion chamber.

Preferably, the inner space of the cylinder occupies 1/5-2/5 of the inner space of the shell, and the first through holes are uniformly arranged on the cylinder and occupy 1/8-1/5 of the surface area of the cylinder.

The low-nitrogen burner provided by the invention is characterized in that gas is introduced through a gas inlet, air is introduced through an air inlet, the gas enters the air classification fluid director through a first-stage gas pipe, after the air enters the shell, one part of the gas enters the air classification fluid director to be mixed with the gas, the other part of the gas reaches the outlet of the air classification fluid director through the outside of the air classification fluid director, and mixed gas is ignited in the process, at the moment, the combustion is divided into two processes: process 1: the mixed gas in the air grading fluid director burns under the conditions of oxygen deficiency and fuel-rich combustion, so that the combustion speed and temperature are reduced, the combustion process is delayed, and the generation of NO is reduced in a reducing atmosphere_xReaction rate of (3), inhibiting NO_xThe amount of production in this combustion; and (3) process 2: the flue gas generated by combustion in the process 1 reaches the outlet position of the air classification fluid director and then is mixed with the other part of air, so that the flue gas is fully combusted again in an environment with sufficient oxygen, and flame is formed at the combustion chamber. In the application, the air entering the shell is divided into two parts which are respectively mixed with the fuel gas, and in the process 1, the combustion temperature is reduced through anoxic combustion, so that the generation of nitrogen oxides is reduced; in the whole process, N₂The residence time in the high temperature zone is mainly in the process 2, thereby reducing N₂The residence time in the high-temperature area of the whole process further reduces the generation of nitrogen oxides, thereby reducing the emission of the nitrogen oxides.

Drawings

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

FIG. 1 is a schematic structural diagram of a conventional low-nitrogen burner;

FIG. 2 is a schematic structural diagram of a low-nitrogen burner provided by the invention;

FIG. 3 is a schematic view of the internal structure of a low-nitrogen burner provided by the present invention;

FIG. 4 is an enlarged view of FIG. 3 at A;

FIG. 5 is a schematic view of an igniter installation location;

FIG. 6 is a schematic structural view of an air classifying deflector in a low nitrogen burner according to the present invention;

FIG. 7 is a schematic view of an axial mounting arrangement of a support structure of the present invention;

FIG. 8 is a side mounting structure of a support structure of the present invention;

reference numbers in the figures: 1-a gas inlet; 11-first-stage gas pipe; 111-secondary gas pipe; 12-an air classification deflector; 121-cylinder body; 122-a spinning disk; 123-a first via; 124-a second via; 125-projection; 126-outlet of the spinning disk; 127-gas hole; 13-a first strut; 14-a second strut; 15-a first connecting rod; 16-a second connecting rod; 17-a third connecting rod; 18-a fourth connecting rod; 19-a connecting plate; 2-a shell; 210-a first stage draft tube; 211-a secondary draft tube; 212-three stages of draft tubes; 213-gas through hole; 214-primary air via; 215-a first bevel; 216-a second bevel; 217-secondary air via; 218-a third bevel; 219 — fourth slope; 230-three levels of air through holes; 231-fifth inclined surface; 4-an air inlet; 7-a combustion chamber; 71-a cylindrical housing; 72-a truncated cone shaped housing; 8-igniter.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Example 1

The embodiment provides a low-nitrogen burner, referring to fig. 2-4, comprising a shell 2, wherein one end of the shell 2 is provided with a gas inlet 1 and an air inlet 4, the other end is provided with a combustion chamber 7, a primary gas pipe 11 is installed in the shell 2, one end of the primary gas pipe 11 is communicated with the gas inlet 1, the other end of the primary gas pipe 11 is connected with an air grading fluid director 12, and the inside and the outside of the air grading fluid director 12 are respectively communicated with the combustion chamber 7; the air inlet 4 communicates with the inside and the outside of the air classifying deflector 12, respectively.

The low-nitrogen burner provided by the embodiment is characterized in that gas is introduced through the gas inlet 1, air is introduced through the air inlet 4, the gas enters the air classification fluid director 12 through the first-stage gas pipe 11, after the air enters the shell 2, one part of the gas enters the air classification fluid director 12 to be mixed with the gas, the other part of the gas reaches the outlet position of the air classification fluid director 12 through the outside of the air classification fluid director 12, mixed gas is ignited in the process, and at the moment, the combustion is divided into two processes: process 1: the combustion of the air mixture within the air staging baffle 12 under oxygen-deficient, fuel-rich combustion conditions reduces the combustion rate and temperature, thereby not only delaying the combustion process, but also reducing the formation of NO in a reducing atmosphere_xReaction rate of (3), inhibiting NO_xThe amount of production in this combustion; and (2) a process: the flue gas generated by combustion in the process 1 reaches the outlet position of the air classification diversion 12 and then is mixed with the other part of air, so that the flue gas is fully combusted again in an oxygen-rich environment, and a flame is formed at the combustion chamber 7. In this application, the air that will get into casing 2 divides into two parts and mixes with the gas respectively, at in-process 1, has reduced the burning through the oxygen deficiency burningTemperature, thereby reducing the formation of nitrogen oxides; in the whole process, N₂The residence time in the high temperature zone is mainly in the process 2, thereby reducing N₂The residence time in the high temperature area of the whole process further reduces the generation of nitrogen oxides, and in addition, in the process 1, according to the principle of expansion with heat and contraction with cold, the mixed gas in the air grading fluid director 12 generates relatively less heat when being burnt under the anoxic fuel-rich combustion condition, the gas expansion is smaller, so the N in the air₂The pressure is lower, thereby further reducing the formation of nitrogen oxides.

A secondary gas pipe 111 is fixed on the primary gas pipe 11, one end of the secondary gas pipe 111 is communicated with the primary gas pipe 11, and the other end of the secondary gas pipe is communicated with the combustion chamber 7. The structure can be used for mixing and burning gas in a grading way and air in a grading way to further reduce NO_xMore importantly, in the process 2, the fuel gas from the secondary fuel gas pipe 111 can react with the flue gas from the process 1 again, namely, the NO generated in the combustion in the process 1 meets hydrocarbon radicals CH_iAnd incomplete combustion products CO, H₂C and C_nH_mIn time, a reduction reaction of NO occurs, the reaction formula being:

4NO+CH₄＝2N₂+CO₂+2H₂O

2NO+2C_nH_m+(2n+m/2-1)O₂＝N₂+2nCO₂+mH₂O

2NO+2CO＝N₂+2CO₂

2NO+2C＝N₂+2CO

2NO+2H₂＝N₂+2H₂O

according to this principle, NO can be further reduced_xThe amount of discharge of (c).

The core principle of the present application is as follows: the higher the combustion temperature, the higher the oxygen concentration in the combustion zone, and the longer the residence time for combustion gasification in the high temperature zone, the NO produced_xThe more. Low NO_xThe discharged combustion technology and the combustor realize the oxygen-deficient combustion in the combustion area and reduce the combustion temperature by the staged combustion technologyResidence time, and thus NO inhibition_xGeneration of (1); meanwhile, by means of an external control technology and a flue gas circulation technology, the reduction of NO is further achieved_xThe target of the discharge.

1. Air staged combustion technology

In the first stage, the amount of air fed from the main burner into the furnace one (i.e., into the hollow barrel) is reduced, typically to 70-75% of the total combustion air amount (corresponding to 80% of the theoretical air amount), so that the fuel is first combusted under oxygen-deficient, fuel-rich combustion conditions. The excess air ratio α in the first stage combustion zone is now < 1, thereby reducing the combustion rate and temperature in the combustion zone. Thus, not only is the combustion process delayed, but the formation of NO is reduced in a reducing atmosphere_xReaction rate of (3), inhibiting NO_xThe amount of the product produced in this combustion.

In order to complete the whole combustion process, the rest air required by the complete combustion is sent into the second hearth (i.e. the combustion chamber) through an air guide plate arranged outside the main burner, is mixed with the smoke generated by the first-stage combustion zone under the condition of oxygen-deficient combustion, and the whole combustion process is completed under the condition that alpha is more than 1. In addition, this method remedies the disadvantage of simple low excess air combustion. Suppression of NO with lower excess air ratio in the first stage combustion zone_xThe better the formation effect.

2. Staged fuel combustion technology

NO that has been generated in combustion encounters the hydrocarbon radical CH_iAnd incomplete combustion products CO, H₂C and C_nH_mIn time, a reduction reaction of NO occurs, the reaction formula being:

4NO+CH₄＝2N₂+CO₂+2H₂O

2NO+2C_nH_m+(2n+m/2-1)O₂＝N₂+2nCO₂+mH₂O

2NO+2CO＝N₂+2CO₂

2NO+2C＝N₂+2CO

2NO+2H₂＝N₂+2H₂O

using this principle, fuel (typically 80-85% is selected) is fed into the first stage combustion zone (inside the hollow barrel) at α>1, combustion and NO formation_x. The fuel fed to the primary combustion zone is called primary fuel, the remaining fuel (15-20%) is fed to the secondary combustion zone in the upper part of the main burner, at alpha<1, so that NO produced in the primary combustion zone is generated_xIs reduced to molecular nitrogen in the secondary combustion zone, also called reburning zone, and the fuel fed into the secondary combustion zone is also called secondary fuel, also called reburning fuel. Not only the NO produced in the reburning zone_xReduced and inhibited new NO_xCan make NO_xThe emission concentration of (a) is further reduced. In general, NO can be achieved using fuel staging_xThe emission concentration of (2) is reduced by more than 50%. The upper surface of the reburning zone is also required to be provided with a nozzle of 'over fire wind' to form a third-stage burning zone (burnout zone) so as to ensure the burnout of incomplete combustion products generated in the reburning zone. This reburning is also known as staged combustion of fuel.

3. Low excess air combustion

The low excess air combustion is that the combustion process is carried out under the condition of being as close to the theoretical air quantity as possible, and the NO can be inhibited along with the reduction of the excess oxygen in the flue gas_xAnd (4) generating. This is the simplest way to reduce NO_xA method of discharging. Generally can reduce NO_xDischarging 15-20%.

4. Smoke secondary combustion technology

Experience shows that NO is not less than 15-20% when the smoke reburning rate is 15-20%_xThe discharge concentration can be reduced by about 25%. NO_xThe rate of decrease of (c) increases with the rate of re-combustion of the flue gas. But also on the fuel type and combustion temperature. The higher the combustion temperature, the higher the smoke reburning rate to NO_xThe greater the effect of the rate of decrease.

5. Low NO_xBurner with a burner head

Gas burners are key equipment in industrial kilns and industrial boiler combustion systems. Not only the gas is fed into the hearth through the burner, but also the air required by the gas combustionAlso through the burner into the furnace. From a combustion point of view, the performance of the burner plays a major role in the reliability and economy of the gas combustion system. From NO_xAccording to the formation mechanism of (1), NO is occupied_xMost of the high temperature NO_xIs generated in the stage of gas ignition, so that the air classification, fuel classification and smoke reburning can be used for reducing NO through the specially designed burner structure and changing the air-fuel ratio of the burner_xThe bulk of the concentration is used in the burner to reduce the concentration of oxygen in the ignition region as much as possible and to reduce the temperature of the ignition region appropriately to minimize NO_xFor the purpose of generation, this is low NO_xA burner.

The air classifying deflector 12 can use the existing air classifying deflector, in the present application, the applicant further designs the air classifying deflector 12, referring to fig. 2-4, the air classifying deflector 12 includes a hollow cylinder 121 and a cyclone sheet 122, the hollow cylinder 121 is connected with the cyclone sheet 122, a primary gas pipe 11 is connected with the hollow cylinder 121 and communicated with the inside of the hollow cylinder 121, one end of an outlet 126 of the cyclone sheet 122 is communicated with the inside of the hollow cylinder 121, and the other end is communicated with the combustion chamber 7; the hollow cylinder 121 is provided with a first through hole 123 communicated with the inside of the hollow cylinder 121 so as to facilitate air to be shunted into the inside of the hollow cylinder 121, the outer edge of the spinning disk 122 is circumferentially provided with a second through hole 124 communicated with the combustion chamber 7 so as to facilitate air outside the hollow cylinder 121 to pass through and be mixed with flue gas generated by combustion inside the hollow cylinder 121, the second through hole 124 is generally semicircular, during manufacturing, the outer edge of the spinning disk 122 can be directly and fixedly connected with the inner edge of the shell 2, and is communicated with the combustion chamber 7 only through the second through hole 124, and the structure can fix the air classification fluid director 12 at one end close to the combustion chamber 7 through the spinning disk 122 so as to resist the impact of air flow and anoxic combustion on the air classification fluid director 12; the air inlet 4 is communicated with the inside of the cylinder 121 through a first through hole 123; and is communicated with the combustion chamber 7 through the second through hole 124, the structure is simple and practical. In this application, the inner space of the hollow cylinder 121 preferably occupies the space between 1/5 and 2/5 of the inner space of the housing, the first through holes 123 are uniformly arranged on the hollow cylinder 121 and occupy the space between 1/8 and 1/5 of the surface area of the hollow cylinder 121, and as a modification, the air inlet 4 can also communicate with the inside of the hollow cylinder 121 and the combustion chamber 7 through a pipe.

In a preferred mode, the hollow cylinder 121 is provided with a protrusion 125 in a circumferential direction; first through-hole 123 is a plurality of, and wherein, partly first through-hole 123 is located the one side that arch 125 just is imported 1 to there is the contained angle with the axis of barrel 121, make the air can incline the entering with the gas cross mixing that gets into from one-level gas pipe 11, be favorable to improving mixing efficiency, prevent to a certain extent that the inhomogeneous local abundant burning that causes of gas and air mixing from doing benefit to NO fully burning and doing benefit to_xThe included angle is generally 30-70 degrees, and the other part is positioned on the connecting surface of the hollow cylinder body 121 connected with the primary gas pipe 11; the hollow cylinder 121 and the primary gas pipe 11 are arranged coaxially. In the structure, in the process 1, a part of air enters the hollow cylinder 121 through the first through hole 123 on the connecting surface, is mixed and combusted with the gas entering the hollow cylinder 121 through the first-stage gas pipe 11 to generate smoke and continuously move forward, and the other part of air enters the hollow cylinder 121 through the first through hole 123 on the protrusion 125 to be mixed and combusted with the passing smoke again, so that the internal combustion of the hollow cylinder 121 can be classified, the previous stage has a smaller excess air coefficient alpha than the next stage, and the reduction of the generation of NO is facilitated_xReaction rate of (3), inhibition of NO_xThe amount of the product produced in this combustion. The protrusions 125 may be arranged in multiple layers in the axial direction of the hollow cylinder 121 to form multi-stage combustion within the hollow cylinder 121, further reducing the generation of NO_xReaction rate of (3), inhibition of NO_xThe amount of formation in this combustion is shown schematically in FIG. 1 as two layers of lobes 125. Preferably, referring to fig. 3 and 4, the primary gas pipe 11 extends into the hollow cylinder 121, and the gas hole 127 is disposed on the side wall, so that the gas outlet direction of the gas hole is almost perpendicular to the air inlet direction entering the hollow cylinder 121 through the first through hole 123 on the connecting surface, which is more favorable for uniform mixing of the gas and the air therein. In FIGS. 3 and 4And "→" schematically shows a flow direction of the gas,

the flow direction of the air is schematically shown.

Referring to fig. 6 as a variation, the air classifying deflector 12 includes a first-stage draft tube 210, a second-stage draft tube 211, a third-stage draft tube 212 and a spinning disk 122, the first-stage draft tube 210, the second-stage draft tube 211, the third-stage draft tube 212 and the spinning disk 122 are connected in sequence as a whole, and the inside is communicated, one end of the first-stage draft tube 210 far away from the second-stage draft tube 211 is provided with a gas through hole 213 and a first-stage air through hole 214 and is connected with the first-stage gas tube 11, the axial line of the first-stage air through hole 214 and the axial line of the air classification fluid director 12 form an included angle alpha, so as to guide the entering air, make the air and central line of the gas entering direction have the intersection, so as to be convenient for the entering air to mix with gas, the gas through hole 213 communicates with first class gas pipe 11, one end of outlet 126 of the swirling sheet communicates with the inside of tertiary honeycomb duct 212, another end communicates with combustion chamber 7; the first-stage draft tube 210 is provided with a first inclined plane 215 inclined towards the inner side, the outer surface of the second-stage draft tube 211 is provided with a second inclined plane 216 inclined towards the outer side, the first inclined plane 215 is connected with the second inclined plane 216, the top of the second inclined plane 216 is provided with a second-stage air through hole 217, the axis of the second-stage air through hole 217 and the axis of the air classification fluid director 12 form an included angle which is preferably larger than alpha, on the basis of facilitating the mixing of air and fuel gas entering the second-stage draft tube 211, the length of the second-stage draft tube 211 is shortened as much as possible, the inner side of the second-stage draft tube 211 is provided with a third inclined plane 218 inclined towards the inner side, the outer surface of the third-stage draft tube 212 is provided with a fourth inclined plane 219, the vertical line of the fourth inclined plane 219 and the axis of the air classification fluid director 12 form an included angle beta, beta is generally larger than alpha, the second-stage draft tube 211 is connected with the fourth inclined plane 219, and the bottom of the fourth inclined plane 219 is provided with a third-stage air through hole 230, the axis of the third-stage air through hole 230 and the axis of the air classification deflector 12 form an included angle, the included angle is preferably larger than alpha, the inner side of the third-stage draft tube 212 is provided with a fifth inclined surface 231 inclined inwards, and the outlet 126 of the spinning disk is connected with the fifth inclined surface 231; the outer edge of the swirler 122 is provided withAnd a second through hole 124 communicating with the combustion chamber 7. In the structure, three-stage mixing is formed in the air classification fluid director 12, in the process 1, a part of air enters the primary draft tube 210 through the primary air through holes 214 to be mixed and combusted with the entering fuel gas, the flue gas is generated and continues to move forwards, after the flue gas enters the secondary draft tube 211, the secondary air through hole 217 enters a part of air to be further mixed and combusted with the air to generate secondary flue gas, the secondary flue gas continuously moves forwards to enter the tertiary draft tube 212, the third air through holes 230 allow a portion of air to enter and further mix with the air to be combusted, and the combusted gas enters the combustion chamber 7 through the outlet 126 of the swirl plate and is discharged through the combustion chamber after being mixed with the air from the second through holes 124, in this way, the combustion inside the air classification fluid director 12 can be divided into three stages, and the excess air coefficient alpha of the front stage is smaller than that of the rear stage, so that the generation of NO is reduced._xReaction rate of (3), inhibition of NO_xThe amount of the product produced in this combustion. In addition, the positions of the secondary air through holes 217 and the tertiary air through holes 230 are arranged in an upper and lower alternating mode, and the primary air through holes 214 are obliquely entered to be mixed with the fuel gas, so that the fuel gas or the smoke is impacted at different angles and directions, and the mixing efficiency is higher. The first inclined surface 215 and the third inclined surface 218 have a guiding and gathering effect on the air flow, so that the air is mixed with the entering air when the air is diffused when entering the next stage after passing through the joint, and the mixing of the air is facilitated.

For convenience of ignition, referring to fig. 5, an igniter 8 may also be mounted on the housing 2; the ignition end of the igniter 8 is located in the hollow cylinder 121, and as a preferable mode, the ignition end of the igniter 8 is located on one side of the cylinder 121 close to the primary gas pipe 11, so that the staged combustion of the gas is more facilitated. The ignition end is referred to herein as the ignition location of the igniter, such as the exit location of the gas igniter. The mounting of igniters is well known to those skilled in the art and will not be described in detail herein.

In order to facilitate the sufficient combustion of the flue gas in the process 2, a combustion chamber is arranged between the combustion chamber 7 and the swirl plate 122, namely, a combustion space is reserved between the combustion chamber 7 and the swirl plate 122 so as to facilitate the sufficient combustion of the flue gas after the flue gas and the air are uniformly mixed. Specifically, the combustion chamber is enclosed by a cylindrical shell 71 and a hollow circular truncated cone-shaped shell 72, the cylindrical shell 71, the hollow circular truncated cone-shaped shell 72 and the combustion chamber are integrated, and the inner diameter of the cylindrical shell 71 is larger than that of the combustion chamber; the bottom surface with the large area of the hollow truncated cone-shaped shell 72 is connected with the cylindrical shell 71, the bottom surface with the small area of the hollow truncated cone-shaped shell 72 is connected with the combustion chamber, and in the structure, air diffuses inwards while passing through the second through hole 124, moves forwards while passing through the inner side surface of the truncated cone-shaped shell 72, and is limited by the shape of the inner side surface of the truncated cone, diffuses forwards and inwards along the inner side surface of the truncated cone, and the smoke coming out from the outlet of the cyclone sheet 122 moves forwards while diffusing outwards, particularly to the bottom surface with the small area of the truncated cone-shaped shell, and is interwoven inside and outside, so that the mixture is more uniform.

Example 2

In this embodiment, be provided with not second through-hole 124 on spinning disk 122, during the installation, there is the interval between the outward flange of spinning disk 122 and the casing 2 to the air current flows, promptly: the shell 2 is hollow, the air classification fluid director 12 comprises a hollow cylinder 121 and a cyclone sheet 122, the hollow cylinder 121 is connected with the cyclone sheet 122, the primary gas pipe 11 is connected with the hollow cylinder 121 and communicated with the inside of the hollow cylinder 121, one end of an outlet of the cyclone sheet is communicated with the inside of the hollow cylinder 121, and the other end of the outlet of the cyclone sheet is communicated with the combustion chamber 7; a first through hole 123 communicated with the inside of the hollow cylinder is formed in the hollow cylinder 121, and a space is formed between the outer edge of the spinning disk 122 and the shell 2; the air inlet 4 is communicated with the inside of the cylinder 121 through a first through hole 123; and communicates with the combustion chamber 7 through the space between the swirler plate 122 and the housing 2. The structure has the advantages that air can directly pass through the outer edge of the cyclone plate 122, the flowing gas is more uniform and is more favorably mixed with flue gas in the process 1, in order to resist the impact of air flow and anoxic combustion on the air classification flow guider, a supporting structure is arranged on the hollow cylinder 121, referring to fig. 7 and 8, the supporting structure is generally arranged in a plurality of numbers, 4 are schematically shown in fig. 6, the supporting structure comprises a plurality of supporting bodies, 2 are schematically shown in fig. 7, the supporting bodies are arranged in an axial parallel manner, each supporting body comprises a first supporting rod 13 and a second supporting rod 14 which are circumferentially fixed between the hollow cylinder and a cylindrical shell, a first connecting rod 15, a second connecting rod 16, a third connecting rod 17 and a fourth connecting rod 18 are arranged between the first supporting rod 13 and the second supporting rod 14, the first connecting rod 15 and the third connecting rod 17 are fixed on the first supporting rod 13, the second connecting rod 16 and the fourth connecting rod 18 are fixed on the second supporting rod 14; a connecting plate 19 is fixedly connected among the first connecting rod 15, the second connecting rod 16, the third connecting rod 17 and the fourth connecting rod 18, the extension line of the first connecting rod 15 is intersected with the extension line of the third connecting rod 17, and the extension line of the second connecting rod 16 is intersected with the extension line of the fourth connecting rod 18; a first connecting rod 15, a second connecting rod 16, a third connecting rod 17 and a fourth connecting rod 18 are arranged between the first supporting rods 13 between the adjacent supporting bodies, the first connecting rod 15 and the third connecting rod 17 are fixed on one of the first supporting rods 13, and the second connecting rod 16 and the fourth connecting rod 18 are fixed on the other one of the first supporting rods 13; a connecting plate 19 is fixedly connected among the first connecting rod 15, the second connecting rod 16, the third connecting rod 17 and the fourth connecting rod 18, the extension line of the first connecting rod 15 is intersected with the extension line of the third connecting rod 17, and the extension line of the second connecting rod 16 is intersected with the extension line of the fourth connecting rod 18; a first connecting rod 15, a second connecting rod 16, a third connecting rod 17 and a fourth connecting rod 18 are arranged between the second supporting rods 14 between the adjacent supporting bodies, the first connecting rod 15 and the third connecting rod 17 are fixed on one of the second supporting rods 14, and the second connecting rod 16 and the fourth connecting rod 18 are fixed on the other second supporting rod 14; and a connecting plate 19 is fixedly connected among the first connecting rod 15, the second connecting rod 16, the third connecting rod 17 and the fourth connecting rod 18, the extension line of the first connecting rod 15 is intersected with the extension line of the third connecting rod 17, and the extension line of the second connecting rod 16 is intersected with the extension line of the fourth connecting rod 18. It should be noted that, in order to fit the shape of the housing, the first connecting rod 15, the second connecting rod 16, the third connecting rod 17 and the fourth connecting rod 18 may be arranged in an arc shape or a straight shape. In the structure, the first connecting rod 13 and the second connecting rod 14 of the support body are matched with the shapes of the hollow cylinder and the cylindrical shell, two arched supports are formed at two ends of the first connecting rod 13 and the second connecting rod 14 to resist the impact of airflow and anoxic combustion on the air classification fluid director 12 in the direction perpendicular to the axial direction, the first connecting rod 15, the second connecting rod 16, the third connecting rod 17 and the fourth connecting rod 18 are matched with the connecting plates to be mutually restricted in the circumferential direction, and when the airflow and the anoxic combustion generate force in the circumferential direction, pulling force or pushing force can be generated to resist the impact of the airflow and the anoxic combustion in the circumferential direction. Similarly, a first connecting rod 15, a second connecting rod 16, a third connecting rod 17 and a fourth connecting rod 18 are arranged between the first supporting rods 13 between the adjacent supporting bodies and are matched with the connecting plates, so that the impact generated by airflow and anoxic combustion in the axial direction can be resisted. Of course, the first connecting rod 15, the second connecting rod 16, the third connecting rod 17 and the fourth connecting rod 18 can be arranged between the supporting structures to match with the connecting plate 19, so that a mutually matched structure for resisting the impact generated by airflow and oxygen-deficient combustion is formed, and the effect is better.

Set up second through-hole 124 on spinning disk 122, during the installation, there is the interval between the outward flange of spinning disk 122 and casing 2.

The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; also, it is obvious to those skilled in the art that various changes and modifications can be made in the embodiments and applications of the invention. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims

1. A low-nitrogen burner, comprising: the air-conditioning device comprises a shell, a primary gas pipe, a secondary gas pipe and an air grading fluid director, wherein one end of the shell is provided with a gas inlet and an air inlet, and the other end of the shell is provided with a combustion chamber; the primary gas pipe and the secondary gas pipe are both arranged in the shell, one end of the primary gas pipe is communicated with the gas inlet, one end of the secondary gas pipe is communicated with one end of the primary gas pipe close to the gas inlet, and the other end of the secondary gas pipe faces the combustion chamber; the air classification fluid director is arranged in the shell, an air channel is formed between the outer wall of the air classification fluid director and the inner wall of the shell, one port of the air classification fluid director is communicated with one end, far away from the fuel gas inlet, of the first-stage fuel gas pipe, and the other port of the air classification fluid director faces the combustion chamber.

2. The low-nitrogen burner of claim 1, wherein the air staging diffuser comprises a hollow cylinder and a swirl plate, the cylinder is connected with the swirl plate, the primary gas pipe is connected with the cylinder and communicated with the interior of the cylinder, one end of an outlet of the swirl plate is communicated with the interior of the cylinder, and the other end of the outlet of the swirl plate is communicated with the combustion chamber; a first through hole communicated with the interior of the cylinder is formed in the cylinder, and a second through hole communicated with the combustion chamber is formed in the circumferential direction of the outer edge of the spinning disk; the air inlet communicates with the interior of the cylinder through the first through hole and communicates with the combustion chamber through the second through hole.

3. The low-nitrogen burner according to claim 2, wherein the cylinder is provided with a plurality of protrusions in the circumferential direction, the first through holes are formed in a plurality of numbers, one part of the first through holes are located on one side of the protrusion opposite to the gas inlet and form an included angle with the axis of the cylinder, the other part of the first through holes are located on the connecting surface of the cylinder and the first-stage gas pipe, and the cylinder and the first-stage gas pipe are coaxially arranged.

4. The low-nitrogen burner of claim 3, wherein the primary gas pipe extends into the barrel, and a gas hole is formed in a side wall of the primary gas pipe extending into the barrel.

5. The low-nitrogen burner of claim 1, wherein the air classification flow director comprises a first-stage flow guide pipe, a second-stage flow guide pipe, a third-stage flow guide pipe and a swirl plate, the first-stage flow guide pipe, the second-stage flow guide pipe, the third-stage flow guide pipe and the swirl plate are sequentially connected into a whole and are internally communicated, a gas through hole and a first-stage air through hole are formed in one end of the first-stage flow guide pipe, which is far away from the second-stage flow guide pipe, and are connected with the first-stage gas pipe, an included angle is formed between the axis of the first-stage air through hole and the axis of the air classification flow director, the gas through hole is communicated with the first-stage gas pipe, one end of an outlet of the swirl plate is communicated with the interior of the third-stage flow guide pipe, and the other end of the outlet of the swirl plate is communicated with the combustion chamber; the first-stage flow guide pipe is provided with a first inclined plane which inclines towards the inner side, the outer surface of the second-stage flow guide pipe is provided with a second inclined plane which inclines towards the outer side, the first inclined plane is connected with the second inclined plane, the top of the second inclined plane is provided with a second-stage air through hole, the axis of the second-stage air through hole and the axis of the fluid director form an included angle, the inner side of the second-stage flow guide pipe is provided with a third inclined plane which inclines towards the inner side, the outer surface of the third-stage flow guide pipe is provided with a fourth inclined plane, the second-stage flow guide pipe is connected with the fourth inclined plane, the bottom of the fourth inclined plane is provided with a third-stage air through hole, the axis of the third-stage air through hole and the axis of the fluid director form an included angle, the inner side of the third-stage flow guide pipe is provided with a fifth inclined plane which inclines towards the inner side, and the outlet of the spinning disk is connected with the fifth inclined plane; the outward flange of spinning disk be provided with the second through-hole of combustion chamber intercommunication.

6. The low-nitrogen combustor according to claim 1, wherein the combustion chamber is defined by a cylindrical casing and a hollow truncated cone-shaped casing, the cylindrical casing and the truncated cone-shaped casing are integrally provided, the truncated cone-shaped casing has a large-area bottom surface connected to the cylindrical casing, and the truncated cone-shaped casing has a small-area bottom surface connected to the combustion chamber.

7. The low-nitrogen burner of claim 2, wherein an igniter is mounted on the housing; the firing end of the igniter is located within the barrel.

8. The low-nitrogen burner of claim 7, wherein the firing end of the igniter is located on a side of the barrel adjacent to the primary gas pipe.

9. The low-nitrogen burner of claim 2, wherein an end of the secondary gas pipe, which is far away from the primary gas pipe, is communicated with the combustion chamber through the swirl plate.

10. The low-nitrogen burner of claim 2, wherein the cylinder inner space occupies 1/5-2/5 of the housing inner space, and the first through holes are uniformly arranged on the cylinder and occupy 1/8-1/5 of the cylinder surface area.