CN212456826U - High-efficiency low-NOx double-vortex flow pulverized coal burner - Google Patents

Abstract

A high-efficiency low-NOx double-vortex flow pulverized coal burner relates to the technical field of clean energy combustion. The problems that the coal type adaptability of the existing cyclone pulverized coal burner is poor, the technology for inhibiting NOx emission is incomplete, and efficient low-NOx pulverized coal combustion is difficult to realize are solved. The utility model discloses a fuel is hierarchical, promptly: the traditional primary air coal dust airflow is divided into an inner air flow and an outer air flow which have the same coal quality or different coal qualities; and (3) separating the concentration, namely: carrying out concentration separation on the inner primary air coal dust airflow and the outer primary air coal dust airflow by utilizing an inner conical concentrator and an outer conical concentrator; grading air distribution, namely: the inner secondary air and the outer secondary air which are respectively and independently controlled are respectively matched with the inner primary air and the outer primary air pulverized coal airflow and are sprayed into the furnace in a coordinated manner, and the central pipe provides central air; the outer vortex flow pulverized coal airflow is continuously ignited based on the absolute ignition stable combustion of the inner vortex flow pulverized coal airflow, so that various NOx are effectively reduced; the utility model discloses mainly used realizes that the buggy catches fire surely to fire, high-efficient low NOx burning.

Description

High-efficiency low-NOx double-vortex flow pulverized coal burner

Technical Field

The utility model relates to a clean energy burning technical field.

Background

At present, in the primary energy composition of China, the proportion of coal still reaches more than 70 percent, which is 40 percent higher than the average level in the world, and the proportion of the coal in China accounting for the total consumption amount of the primary energy still exceeds 50 percent in 2030 years, and the consumption amount reaches about 45 hundred million tons. The average comprehensive utilization efficiency of power generation and heat supply in China is only about 40 percent, which is 10 percent lower than that of developed countries, and SO discharged by coal₂90% of NOx, 75% of total suspended particulate matter, 60% of CO₂Accounting for 75 percent. In China, the low-quality coal reaches about 50% in the coal storage volume, the ratio of only anthracite to lean coal is close to 30%, and a large amount of coke produced by lignite upgrading or low-temperature pyrolysis also needs a novel combustion and gasification technology to be cleanly and efficiently utilized. The thermal power generated by direct combustion of coal accounts for over 70 percent of the total power generation amount of China, and the coal provides 80 percent of thermal power fuel, wherein the majority of thermal power plants use inferior coal. In addition, the coal quality of the power coal in China is unstable and often cannot reach the design coal standard. CO (carbon monoxide) continuously increased in research and development of coal clean and efficient utilization technology₂The international background of capture requirements is becoming more stringent. Chinese thermal power recent target: average power standard coal consumption is reduced to 315 g/kilowatt hour S0₂The emission concentration is controlled to be 30mg/Nm3, and the emission concentration of NOX is controlled to be 50mg/Nm3, which is the internal power of the development of novel coal burning technology in China.

The rotational flow pulverized coal combustion technology is one of key technologies in the clean and efficient utilization technology of coal, and compared with the traditional direct-current pulverized coal combustion technology, the rotational flow pulverized coal combustion technology has the advantages that the rotational flow pulverized coal combustion technology is widely applied due to the excellent characteristics of no thermal deviation problem, excellent ignition and stable combustion performance, convenience in arrangement of heating surfaces and the like; but also has the problems of poor coal type adaptability, higher coal quality requirement, and especially high emission of nitrogen oxides (NOx), which is also a technical reason that the swirl pulverized coal combustion technology is difficult to be listed in the Chinese ultra-clean emission technical list within a period of time. Although various rotational flow pulverized coal combustion technologies are developed at home and abroad, the challenges still exist in simultaneously realizing clean and efficient pulverized coal combustion and utilization with stable ignition, high efficiency, low NOx, no slag bonding, excellent low-load performance and the like.

The prior art provides a cyclone pulverized coal burner, which adopts the structural design of easy-to-fire coal central powder feeding and Venturi tube type inner and outer secondary air and aims to realize the ignition and stable combustion of the primary air of cyclone pulverized coal combustion by utilizing the ignition and stable combustion of the easy-to-fire coal. The technology has the problems that the internal reflux area is possibly overheated to be unfavorable for thermal NOx inhibition due to uncertain powder supply amount of the easily-fired coal, no targeted technical measures are implemented for inhibiting the fuel NOx, the secondary air is mixed into the primary air too early to be favorable for ignition and stable combustion of the primary air, and the low-quality coal, especially low-volatile anthracite, lean coal and coke, are difficult to realize high-efficiency low-NOx combustion; in addition, for difficult-to-fire coal, the strong external backflow area caused by the venturi tube type internal and external secondary air is easy to cause the flame to be close to the water wall; in addition, the manner of supply and the amount of supply of the center inflammable coal were not scientifically evaluated.

The prior art also provides a rotational flow pulverized coal burner, primary air is concentrated by the inner concentration and the outer dilution and then is centrally sprayed into a central backflow area, ignition and stable combustion are facilitated, but the inherent characteristic that the concentrated flame is difficult to cool is difficult to inhibit the generation of thermal NOx.

The prior art also provides a rotational flow pulverized coal burner, after primary air is concentrated by the outer part of a Venturi tube and is concentrated by the inner part of the Venturi tube, concentrated pulverized coal airflow is sprayed into the outer boundary layer of a backflow region, light pulverized coal airflow is sprayed in the center, flame can be timely cooled by secondary air, NOx emission is favorably reduced, but for poor-quality coal, particularly difficult-to-burn coal, because the concentrated pulverized coal airflow cannot be directly heated by the backflow region of a high-temperature center, the Venturi tube type concentration effect is poor, the ignition stability and the fuel type NOx emission inhibition performance have limitations, and the coal type adaptability is poor.

In summary, the conventional swirling pulverized coal burner or swirling pulverized coal combustion technology is poor in coal adaptability and incomplete in NOx emission suppression technology, and is difficult to meet the requirement of high-efficiency low-NOx pulverized coal combustion. Therefore, the above problems need to be solved.

SUMMERY OF THE UTILITY MODEL

The utility model relates to a solve current whirl pulverized coal burner coal adaptability poor, restrain the incomplete problem that is difficult to realize high-efficient low NOx pulverized coal burning of NOx emission technique, provide a high-efficient low NOx two vortex flow pulverized coal burner.

A high-efficiency low-NOx double-vortex-flow pulverized coal burner comprises a central pipe, an inner primary air pipe, an inner secondary air pipe, an outer primary air pipe and an outer secondary air pipe which are coaxially arranged from inside to outside in sequence, wherein the top ports of the inner primary air pipe, the inner secondary air pipe, the outer primary air pipe and the outer secondary air pipe are sealed, and the bottom ports are communicated; the device also comprises an inner cone-shaped concentrator, an outer cone-shaped concentrator, a radial swirler and an axial swirler;

the top port of the central pipe extends out of the top port of the inner primary air pipe, and the central pipe is used for introducing air;

the side walls of the inner primary air pipe, the inner secondary air pipe, the outer primary air pipe and the outer secondary air pipe are respectively provided with an inner primary air inlet, an inner secondary air inlet, an outer primary air inlet and an outer secondary air inlet, and the coal quality of the pulverized coal airflow introduced from the inner primary air inlet and the outer primary air inlet is the same or different;

the inner secondary air inlet and the outer secondary air inlet are used for introducing air;

the inner conical concentrator is arranged in a channel enclosed by the inner wall of the inner primary air pipe and the outer wall of the central pipe and is used for carrying out concentration separation on pulverized coal airflow introduced into the inner primary air pipe;

the outer conical concentrator is arranged in a channel defined by the outer wall of the inner secondary air pipe and the inner wall of the outer primary air pipe and is used for carrying out concentration separation on the pulverized coal airflow introduced into the outer primary air pipe;

the radial swirler is used for radially swirling air introduced into the inner secondary air pipe;

the axial cyclone is used for carrying out axial cyclone on air introduced into the external secondary air pipe.

Preferably, the pulverized coal burner further comprises an inner adapter ring, and the inner adapter ring is communicated with the bottom port of the inner primary air pipe through a diffusion ring.

Preferably, the pulverized coal burner further comprises an outer adapter ring, and the outer adapter ring is communicated with the bottom port of the outer primary air pipe through another diffusion ring.

Preferably, the bottom port of the inner adapter ring extends out of the bottom port of the inner secondary air pipe;

the central tube runs through the inner cone concentrator, and the bottom port of the central tube extends out of the inner cone concentrator.

Preferably, the inner cone-shaped concentrator and the outer cone-shaped concentrator are both realized by tapered conical pipes or tapered conical pipes, the inner cone-shaped concentrator and the outer cone-shaped concentrator are vertically provided with a plurality of layers of flow equalizing channels in the circumferential direction along the side walls of the inner cone-shaped concentrator and the outer cone-shaped concentrator, and each layer of flow equalizing channel comprises a plurality of flow equalizing holes;

the total flow area of the flow equalizing holes on the inner cone concentrator or the outer cone concentrator is at least larger than the maximum flow area of the open end of the concentrator where the flow equalizing holes are located.

Preferably, the flow equalizing holes in two adjacent flow equalizing channels on the inner cone-shaped concentrator and the outer cone-shaped concentrator are distributed in a staggered mode, and the number of the flow equalizing holes in the two adjacent flow equalizing channels is 2 times.

Preferably, the taper angle A of the tapered cone is₁The taper angle is an acute angle formed by an extension surface of the tapered end of the tapered conical pipe and the axis of the tapered conical pipe, and the value range of the acute angle is 10-35 degrees;

divergent angle A of divergent cone₂The acute angle is formed by the extension surface of the reducing end of the gradually expanding taper pipe and the axis of the gradually expanding taper pipe, and the value range of the acute angle is 10-35 degrees.

Preferably, the diffusion angle A of the diffusion ring₃Is 35 degrees, the diffusion ring is a gradually expanded ring body, and the diffusion angle A is₃Is the included angle between the extension surface of the contraction end of the gradually-expanded ring body and the axis thereof.

Preferably, the inner primary air pipe has an inner diameter D₁The distance between the bottom port of the inner cone-shaped concentrator and the bottom port of the inner adapter ring is H₁And H is₁＝K₁D₁，K₁Is a coefficient, K₁The value of (a) is in the range of 0.5 to 1.

Preferably, the inner diameter of the outer primary air pipe is D₂External cone type concentrationThe distance between the bottom port of the device and the bottom port of the outer adapter ring is H₂And H is₂＝K₂D₂，K₂Is a coefficient, K₂The value of (a) is in the range of 0.5 to 1.

Preferably, the proportion (25-30)% of the pulverized coal airflow introduced into the inner primary air inlet and the outer primary air inlet is as follows: (75-70)%.

Preferably, the air is introduced into the inner secondary air pipe and the outer secondary air pipe in a proportion (25-30)%: (75-70)%.

Preferably, the radial section of the tapered conical pipe is circular, rectangular or square;

the radial section of the divergent taper pipe is round, rectangular or square.

It is preferable that the first and second liquid crystal layers are formed of,

when the inner cone-shaped concentrator is a tapered cone pipe, the inner cone-shaped concentrator is fixed on the inner wall of the inner primary air pipe, when the inner cone-shaped concentrator is a tapered cone pipe, the inner cone-shaped concentrator is fixed on the outer wall of the central pipe, and the outer diameter of the opened end of the inner cone-shaped concentrator is smaller than the inner diameter D of the inner primary air pipe₁；

When the inner conical concentrator is a tapered conical pipe, the bottom port of the inner conical concentrator is used as a tapered end, and the top port of the inner conical concentrator is used as an open end;

when the inner conical concentrator is a gradually expanding conical pipe, the bottom port of the inner conical concentrator is used as an opening end, and the top port of the inner conical concentrator is used as a contraction end;

when the outer conical concentrator is a tapered conical pipe, the outer conical concentrator is fixed on the inner wall of the outer primary air pipe, the bottom port of the outer conical concentrator serves as a tapered end, the top port serves as an open end, and the inner diameter of the tapered end is larger than the outer diameter of the inner secondary air pipe;

and (III) when the outer conical concentrator is a divergent conical pipe, the outer conical concentrator is fixed on the outer wall of the inner secondary air pipe, the bottom port of the outer conical concentrator is used as an open end, the top port is used as a contracted end, and the outer diameter of the open end is smaller than the inner diameter of the outer primary air pipe.

Preferably, the inside diameter D 'of the tapered cone at the beginning'₃And the inner diameter D' of the contracted end₃The ratio range of (A) is 10: 7 to 10: 8;

divergent typeOpen end inner diameter D 'of conical tube'₄And the inner diameter D' of the contracted end₄The ratio range of (A) is 10: 7 to 10: 8.

Preferably, when the coal quality introduced into the inner primary air inlet and the outer primary air inlet is the same, the coal introduced into the inner primary air inlet and the outer primary air inlet is easy-to-fire coal, high-quality coal, mixed coal of the easy-to-fire coal and the difficult-to-fire coal, mixed coal of the easy-to-fire coal and poor-quality coal, mixed coal of the high-quality coal and the difficult-to-fire coal or mixed coal of the high-quality coal and the poor-quality coal;

when the coal quality introduced into the inner primary air inlet and the outer primary air inlet is different, the coal introduced into the inner primary air inlet is easily-fired coal or high-quality coal, and the coal introduced into the outer primary air inlet is difficultly-fired coal, inferior coal or mixed coal of the difficultly-fired coal and the inferior coal.

Preferably, the pulverized coal burner may be disposed horizontally, vertically or obliquely on the combustion device.

The utility model discloses a fuel is hierarchical, adopts the simplest structural design optimization thick and thin burning to scientifically match with hierarchical overgrate air, when guaranteeing to catch fire surely to fire and surely fire and improve coal type adaptability, effectively restrain heating power type and fuel type NOx and discharge, both realized the burning of two vortex flow buggy "diffusion formula" of a high-efficient low NOx, provide a two vortex flow buggy burners of high-efficient low NOx again.

Fuel classification, namely dividing a traditional primary air pulverized coal airflow into an inner concentric primary air pulverized coal airflow ring and an outer concentric primary air pulverized coal airflow ring which have the same or different coal qualities by concentrically arranging two primary air pipelines to implement fuel classification;

performing concentration separation, namely performing concentration separation on the inner primary air coal powder airflow ring and the outer primary air coal powder airflow ring respectively by utilizing an inner conical concentrator and an outer conical concentrator which are provided with flow equalizing holes vertically or obliquely according to a certain principle;

the grading air distribution is different from the traditional double-adjustment secondary air, the utility model utilizes the inner secondary air pipeline and the outer secondary air pipeline which are concentrically arranged, and the independently adjustable inner secondary air and the outer secondary air are respectively and directly arranged at the outer sides of the inner primary air pulverized coal airflow ring and the outer primary air pulverized coal airflow ring; the inner adapting ring and the outer adapting ring are respectively arranged at the inner air coal powder airflow outlet and the outer air coal powder airflow outlet in order to delay the mixing of the first air and the second air and stabilize the ignition; and the central wind is provided through the configured central pipe.

The principle of ignition and stable combustion: the inner primary air pulverized coal airflow, the inner conical concentrator, the inner secondary air, the inner adapter ring and the central air form inner vortex flow thick and thin pulverized coal combustion which can independently run, namely: an internal vortex flow pulverized coal burner;

the outer primary air pulverized coal airflow, the outer conical concentrator, the outer secondary air, the outer adapter ring and the inner vortex flow pulverized coal burner form outer vortex flow thick and thin pulverized coal combustion, namely: the outer vortex flow pulverized coal burner is fired and stably combusted through the firing and stable combustion of the inner vortex flow pulverized coal burner which is absolutely fired and stably combusted, and because pulverized coal of inner and outer primary air pulverized coal airflow can be heterogeneous, the inner primary air pulverized coal airflow can be independently provided with coal quality which is beneficial to the firing and stable combustion, such as easily-fired coal or high-quality coal, controllable pulverized coal quantity, such as 30% and the like, so that the inner vortex flow pulverized coal burner is absolutely fired and stably combusted, the outer vortex flow pulverized coal burner is continuously ignited, and the diffusion type absolute firing and stable combustion of the double vortex flow pulverized coal burner is realized.

Low NOx emission principle: due to the fuel staging, the concentrated flame is reconfigured into inner and outer dual flames and directly matches the adjustable secondary air, respectively, and therefore, the cooling of the flame is easily organized and implemented, and the fire is designed to occur preferentially at the outer boundary layer of the vortex to avoid overheating and oxygen enrichment in the vortex core region, thereby enabling the reduction of the generation of thermal NOx; the inner and outer double flames are both subjected to thick and thin combustion, so that the emission of fuel NOx can be reduced; for the inner primary air coal powder air flow and the outer primary air coal powder air flow, the radial multiple volatile components reformed by the concentration separation and the coal powder particle fuel ring are integrated, the combustion of any outer ring fuel to the inner ring fuel is fuel classification so as to strengthen the reduction of the generated NOx and reduce the emission of the NOx; the NOx reduction principle of secondary air classification is similar to the NOx reduction principle of traditional double-adjusting secondary air, so that the NOx emission is effectively reduced through thick and thin combustion, secondary air classification and fuel classification.

Evaluation: under ideal conditions, the coal powder concentration of the concentrated primary air coal powder airflow reformed by the conical concentrator provided with the flow equalizing holes is at least doubled, and the concentrated coal powder airflow is subjected to a section of inertial concentration and dilution separation before ignition, so that the concentrated coal powder airflowThe concentration of the pulverized coal can be improved by more than one time, so that the high-efficiency low-NOx pulverized coal combustion can be realized for the inferior coal with only 8% of volatile components theoretically; through optimization, the resistance loss of the conical inner concentrator and the conical outer concentrator is reduced to 20mmH₂An O column; different from the requirement of the traditional fuel classification low NOx emission performance, the utility model discloses a fuel classification both requires to be favorable to low NOx emission, more requires to be favorable to the stable burning of catching fire of pulverized coal burning in the wide range coal type scope, combustion performance is good steady operation when the low-load, therefore, the proportion of inside and outside wind pulverized coal air current preferably maintains about 3:7, carries out combustion performance good regulation matching according to inside and outside secondary air volume; because the inner primary air pulverized coal airflow can be independently configured with easy-to-burn coal or high-quality coal, the utility model is particularly suitable for the diffusion type mixed burning of easy-to-burn coal and difficult-to-burn coal or high-quality coal and inferior coal, and is also suitable for the pre-mixing type mixed burning and the burning of high-quality coal. In addition, when the inner secondary air and the outer secondary air are direct currents, the high-efficiency low-NOx double-vortex-flow pulverized coal burner is a direct-current pulverized coal burner.

The utility model has the advantages of that, the utility model provides a high-efficient low NOx double vortex flow pulverized coal burner implements the fuel classification with traditional primary wind pulverized coal air through establishing independent powder supply system separately, divide into inside and outside two strands of primary wind pulverized coal air flows, and inside and outside primary wind pulverized coal air flow can be homogeneous also can be heterogeneous, inside and outside primary wind pulverized coal air flow respectively directly matches the inside and outside overgrate air of hierarchical air distribution, inside primary wind pulverized coal air and inside overgrate air structure become the inner vortex flow pulverized coal burner with the core, can independently operate, outside primary wind pulverized coal air and outside overgrate air structure outer vortex flow burner with the core; the inside and outside primary air pulverized coal airflow respectively utilizes the inside and outside conical concentrators to carry out shade separation, implements shade burning, utilizes the catching fire of the inside primary air pulverized coal airflow to stably burn (inner vortex) and continuously ignite the outside primary air pulverized coal airflow (outer vortex), namely: the inner vortex ignites the outer vortex, so that the double-vortex flow pulverized coal is combusted, and the concentrated flame is eliminated; inside and outside two streams of air buggy air current directly matches inside and outside two streams of overgrate air respectively, and the difference lies in with traditional bitonic overgrate air difference, the utility model discloses inside and outside overgrate air matches the inside and outside air buggy air current of probably heterogeneity respectively. Therefore, the coal type adaptability, high efficiency and low NOx performance of the swirling pulverized coal combustion can be effectively improved through the design of the fuel grading, secondary air grading and optimized concentrator.

The inner cone concentrator and the outer cone concentrator have 4 combination modes, namely a gradual reduction and gradual expansion mode, a gradual expansion and gradual reduction mode and a gradual expansion and gradual expansion mode, and are used for adapting to the high-performance pulverized coal combustion requirements of different coal types; just because the scientific matching of fuel classification (also realized the split of concentrated flame), hierarchical air distribution, the thick and thin burning that can independent control makes the utility model discloses a whirl pulverized coal burner can realize high-efficient, low NOx simultaneously and discharge, prevent the slagging scorification, prevent high temperature corrosion, coal type strong adaptability, the low-load surely fires the ability reinforce.

Experiments and practices show that: the resistance loss of the high-efficiency low-NOx double-vortex flow pulverized coal burner is 30mmH₂And (2) below the O column, the abrasion problem can be effectively solved by utilizing the prior art, and compared with the 'premixed' mixed combustion of low-volatile lean coal and high-quality coal with 19% of volatile, the 'diffused' mixed combustion of low-volatile lean coal and high-quality coal has the advantages that the ignition stable combustion performance and the combustion efficiency are obviously improved, slagging and high-temperature corrosion phenomena are not generated, the high-performance operation can be realized under the load of (25-30%), and the NOx emission is reduced by at least 45%.

The utility model discloses a "diffusion formula" mixes to burn provides theoretical basis, and mainly used easily fire coal (high-quality coal), easily fire coal (high-quality coal) and difficult fire coal (inferior coal), the high-efficient low NOx pulverized coal burning of premixed coal "diffusion formula" because the diffusion burning is absolutely surely burnt, so, uses the utility model discloses a key is the absolutely surely burning of establishing the internal vortex.

Drawings

FIG. 1 is a schematic diagram of a high efficiency low NOx dual vortex pulverized coal burner according to the present invention;

FIG. 2 is a schematic structural view of a high efficiency low NOx double vortex flow pulverized coal burner according to the present invention;

FIG. 3 is a front sectional view of a tapered cone;

FIG. 4 is a front cross-sectional view of a diverging cone;

figure 5 is a schematic view of 4 combinations of inner cone concentrator 6 and outer cone concentrator 7,

fig. 6 is a schematic diagram showing the distribution of the multiphase airflow rings when the inner conical concentrator 6 is a tapered conical pipe and the outer conical concentrator 7 is a tapered conical pipe.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

The present invention will be further described with reference to the accompanying drawings and specific embodiments, but the present invention is not limited thereto.

The utility model discloses a performance whirl buggy burning's central backward flow district is to the effective action of surely firing of firing, and the near field mixes by force, there is not thermal deviation, the afterbody receives the hot side to arrange advantages such as convenience, it is poor to adapt to the nature of coal for solving current whirl buggy burning technique coal, restrain the imperfect problem of NOx emergence technique, from combustor self angle, it is hierarchical to pass through the fuel, adopt the simplest structural design to optimize the dense and light burning, and scientifically match with hierarchical overgrate air, when guaranteeing to fire surely to fire and improve coal adaptability, effectively restrain heating power type and fuel type NOx and discharge, realize the two vortex flow buggy burning of a high-efficient low NOx promptly, a two vortex flow buggy burners of high-efficient low NOx are provided.

Referring to fig. 1 and fig. 2 to illustrate the present embodiment, the high-efficiency low-NOx double-vortex-flow pulverized coal burner according to the present embodiment includes a central pipe 1, an inner primary air pipe 2, an inner secondary air pipe 3, an outer primary air pipe 4 and an outer secondary air pipe 5, which are coaxially disposed from inside to outside, and top ports of the inner primary air pipe 2, the inner secondary air pipe 3, the outer primary air pipe 4 and the outer secondary air pipe 5 are sealed, and bottom ports are communicated; the device also comprises an inner cone-shaped concentrator 6, an outer cone-shaped concentrator 7, a radial swirler 8 and an axial swirler 9;

the top port of the central tube 1 extends out of the top port of the inner primary air tube 2, and the central tube 1 is used for introducing air;

the side walls of the inner primary air pipe 2, the inner secondary air pipe 3, the outer primary air pipe 4 and the outer secondary air pipe 5 are respectively provided with an inner primary air inlet 2-1, an inner secondary air inlet 3-1, an outer primary air inlet 4-1 and an outer secondary air inlet 5-1, and the coal quality of the pulverized coal airflow introduced by the inner primary air inlet 2-1 and the outer primary air inlet 4-1 is the same or different;

the inner secondary air inlet 3-1 and the outer secondary air inlet 5-1 are used for introducing air;

the inner conical concentrator 6 is arranged in a channel enclosed by the inner wall of the inner primary air pipe 2 and the outer wall of the central pipe 1 and is used for carrying out concentration separation on the pulverized coal airflow introduced into the inner primary air pipe 2;

the outer conical concentrator 7 is arranged in a channel enclosed by the outer wall of the inner secondary air pipe 3 and the inner wall of the outer primary air pipe 4 and is used for carrying out concentration separation on the pulverized coal airflow introduced into the outer primary air pipe 4;

the radial swirler 8 is used for radially swirling air introduced into the inner secondary air pipe 3;

the axial cyclone 9 is used for axially swirling air introduced into the external secondary air pipe 5.

In the embodiment, the air introduced through the inner secondary air inlet 3-1 is used for promoting the burnout of the pulverized coal in the inner primary air pipe 2, and the air introduced through the outer secondary air inlet 5-1 is used for promoting the burnout of the pulverized coal in the outer primary air pipe 4.

The air flow introduced by the inner primary air pipe 2 is inner primary air pulverized coal air flow, the air flow introduced by the inner secondary air pipe 3 is inner secondary air flow, the air flow introduced by the outer primary air pipe 4 is outer primary air pulverized coal air flow, and the air flow introduced by the outer secondary air pipe 5 is outer secondary air flow.

The inner and outer primary air pulverized coal airflow and the inner and outer secondary air are provided by mutually independent pipelines, so that the pulverized coal combustion equipment can be independently adjusted and controlled, and the high-performance operation of the pulverized coal combustion equipment is easy to realize: the proportion of the inner primary air pulverized coal airflow and the outer primary air pulverized coal airflow is (0-100)%: (100-0)%, either homogeneous or heterogeneous, and accordingly the ratio of inner secondary air to outer secondary air is (0-100)%: (100-0)%.

The high-efficiency low-NOx double-vortex-flow pulverized coal burner is characterized in that except that the inner conical concentrator 6 and the outer conical concentrator 7 are made of heat-resistant and wear-resistant materials such as alumina iron alloy or ceramics, other parts can be made of heat-resistant and wear-resistant carbon steel.

In order to realize a high-efficiency low-NOx double-vortex-flow pulverized coal combustion technology, the primary air pulverized coal airflow is divided into an inner air flow and an outer air flow, the inner air flow and the outer air flow are respectively and independently sprayed into a hearth after being subjected to concentration separation by adopting an inner conical concentrator and an outer conical concentrator, the inner air flow and the outer air flow can be homogeneous, such as density, particle size distribution and the like, or heterogeneous, such as easily-fired coal and difficultly-fired coal, and the outer air flow and the inner air flow are ignited to realize double-vortex-flow pulverized coal combustion and eliminate centralized flame; inside and outside two streams of air buggy air current directly matches inside and outside two streams of overgrate air respectively, and the difference lies in with traditional bitonic overgrate air difference, the utility model discloses inside and outside overgrate air matches the inside and outside air buggy air current of probably heterogeneity respectively. Therefore, the coal type adaptability, high efficiency and low NOx performance of the swirling pulverized coal combustion can be effectively improved through the design of the fuel grading, secondary air grading and optimized concentrator.

The utility model divides the traditional primary air coal dust airflow into an inner air flow and an outer air flow through fuel classification, and carries out the shade separation on the coal dust airflow introduced into the inner primary air pipe 2 through the inner cone-shaped concentrator 6, and carries out the shade separation on the coal dust airflow introduced into the outer primary air pipe 4 through the outer cone-shaped concentrator 7; the graded air distribution, namely the inner secondary air and the outer secondary air are respectively matched with the inner primary air pulverized coal airflow and the outer primary air pulverized coal airflow after the concentration separation and then are cooperatively sprayed into the furnace, the central air provided by the central pipe 1 is used, the outer primary air pulverized coal airflow (outer vortex) is continuously ignited by utilizing the absolute ignition stable combustion (inner vortex) of the inner primary air pulverized coal airflow, the concentrated flame is eliminated, and the high-efficiency low-NOx double-vortex pulverized coal combustion of easy-to-burn coal or high-quality coal, difficult-to-burn coal or low-quality coal and mixed coal is realized.

Further, referring specifically to fig. 1 and 2, the high efficiency low NOx double vortex pulverized coal burner further comprises an inner adapter ring 10, wherein the inner adapter ring 10 is communicated with the bottom port of the inner primary air pipe 2 through a diffuser ring 11.

In this preferred embodiment, realized carrying out the beam current to the internal air buggy air current through the mode of addding interior adapter ring 10, postponed the mixture of internal air buggy air current and interior overgrate air simultaneously, guaranteed catching fire of air buggy air current surely to fire, promptly: the mixing of the coal dust airflow introduced from the inner primary air inlet 2-1 and the air introduced from the inner secondary air inlet 3-1 is delayed.

Further, referring specifically to fig. 1 and 2, the high efficiency low NOx double vortex pulverized coal burner further comprises an outer adapter ring 12, wherein the outer adapter ring 12 is communicated with the bottom port of the outer primary air pipe 4 through another diffusion ring 11.

In this preferred embodiment, realized carrying out the beam current to outer primary air buggy air current through the mode of addding outer adapter ring 12, postponed the mixture of outer primary air buggy air current and outer overgrate air simultaneously, guaranteed that the firing of overgrate air buggy air current is surely fired, promptly: the mixing of the coal dust flow introduced from the outer primary air inlet 4-1 and the air introduced from the outer secondary air inlet 5-1 is delayed. Therefore, the inner adapter ring and the outer adapter ring have a combustion stabilizing effect.

Further, referring specifically to fig. 1 and 2, the bottom port of the inner adapter ring 10 extends out of the bottom port of the inner secondary air duct 3;

the central tube 1 extends through the inner cone concentrator 6 with its bottom end extending out of the inner cone concentrator 6. More preferably, the bottom port of the central tube 1 is flush with the bottom port of the inner primary air duct 2 or with the bottom port of the inner adaptor ring 10.

In the preferred embodiment, the bottom port of the inner adapter ring 10 extends out of the bottom port of the inner secondary air pipe 3, so that the mixing of the inner primary air pulverized coal airflow and the inner secondary air is further delayed, and the ignition and stable combustion of the inner primary air pulverized coal airflow are ensured; on the other hand, the central tube 1 extends through the inner cone concentrator 6, and its bottom port extends out of the inner cone concentrator 6, and depending on the coal type, it may also be located between the bottom port of the inner primary air pipe 2 and the bottom port of the inner adapter ring 10.

Further, referring specifically to fig. 3 to 5, the inner cone-shaped concentrator 6 and the outer cone-shaped concentrator 7 are both implemented by tapered conical pipes or tapered conical pipes, the conical surfaces of the tapered conical pipes are preferably straight surfaces, the inner cone-shaped concentrator 6 and the outer cone-shaped concentrator 7 are provided with a plurality of flow equalizing channels in the circumferential direction along the side walls, or part of the through walls, preferably vertically, each layer of flow equalizing channel comprises a plurality of flow equalizing holes 13, and the flow equalizing holes 13 can be in any form, most preferably circular holes;

the total flow area of the flow equalizing openings 13 in the inner cone concentrator 6 or the outer cone concentrator 7 is at least greater than the maximum flow area at the beginning of the concentrator in which they are located.

In the preferred embodiment, the diameter of the opened flow equalizing hole 13 is 10mm to 60mm, and the flow equalizing hole 13 is used for reducing resistance and equalizing flow so as to reduce abrasion and effectively equalize flow.

The concrete matching structure of the inner conical concentrator 6 and the outer conical concentrator 7 has 4 combination relations, which are respectively a gradual reducing type, a gradual reducing and expanding type, a gradual expanding and contracting type and a gradual expanding and expanding type from inside to outside, namely: the first method comprises the following steps: the inner conical concentrator 6 is a tapered conical pipe, and the outer conical concentrator 7 is a tapered conical pipe; and the second method comprises the following steps: the inner conical concentrator 6 is a tapered conical pipe, and the outer conical concentrator 7 is a tapered conical pipe; and the third is that: the inner conical concentrator 6 is a tapered conical pipe, the outer conical concentrator 7 is a tapered conical pipe, and at the moment, radial gas-solid multiphase flow airflow rings are distributed, specifically referring to fig. 6; and fourthly: the inner conical concentrator 6 is a gradually expanding conical pipe, and the outer conical concentrator 7 is a gradually expanding conical pipe.

Therefore, the utility model can be implemented according to different coal quality pertinence by utilizing 4 combinations between the inner cone-shaped concentrator 6 and the outer cone-shaped concentrator 7; for easy-to-burn coal or high-quality coal, the inner cone type concentrator 6 is preferably in a gradually expanding type; for difficult-to-fire coal or low-quality coal, the inner cone type concentrator 6 is preferably in a tapered type; in order to prevent slag bonding of the water-cooled wall and adherence of flame, the outer conical concentrator 7 is preferably in a tapered type, and the outer conical concentrator 7 in a tapered type is more beneficial to efficient combustion under the condition that the slag bonding of the water-cooled wall can be prevented through effective measures.

When the coal dust volatile component of the outer primary air coal dust airflow is more than 14%, the main problems of good ignition and stable combustion performance and low NOx emission are solved, and the outer conical concentrator 7 is preferably a gradually expanding conical pipe;

when the coal dust volatile component of the outer primary air coal dust airflow is less than 14%, ignition and stable combustion are main problems, and the outer conical concentrator 7 is preferably a tapered conical pipe;

the outer cone-shaped concentrator 7 is coaxially and symmetrically arranged in an annular channel leading to the furnace from an outlet formed by the inner secondary air pipe 3 and the outer primary air pipe 4, when the outer cone-shaped concentrator 7 is a gradually expanding cone pipe, the outer primary air pulverized coal airflow is concentrated and separated into two pulverized coal airflow rings with inner light and outer thick, and then the two pulverized coal airflow rings are sprayed into the furnace to implement thick and thin combustion, and when the outer cone-shaped concentrator 7 is a gradually contracting cone pipe, the outer primary air pulverized coal airflow is concentrated and separated into two pulverized coal airflow rings with inner light and outer thin, and then the two pulverized coal airflow rings are sprayed into the furnace to implement thick and thin combustion.

Further, referring to fig. 3 to 5, the flow equalizing holes 13 on two adjacent layers of flow equalizing channels on the inner cone-shaped concentrator 6 and the outer cone-shaped concentrator 7 are distributed in a staggered manner, and the number of the flow equalizing holes 13 on two adjacent layers of flow equalizing channels is 2 times.

In the preferred embodiment, the aperture of the flow equalizing holes 13 on two adjacent layers of flow equalizing channels is the same or different.

Further, with particular reference to fig. 3 and 4, the taper angle a of the tapered cone₁The taper angle is an acute angle formed by an extension surface of the tapered end of the tapered conical pipe and the axis of the tapered conical pipe, and the value range of the acute angle is 10-35 degrees, and most preferably 30 degrees;

divergent angle A of divergent cone₂Is an acute angle formed by the extension surface of the reducing end of the gradually expanding taper pipe and the axis of the gradually expanding taper pipe, and the value of the acute angle ranges from 10 degrees to 35 degrees, and is most preferably 30 degrees.

In the preferred embodiment, the taper angle A₁Is 30 DEG, and a divergent angle A₂Is 30 °; practice shows that under the preferred conditions, the resistance loss of the high-efficiency low-NOx double-vortex-flow pulverized coal burner is less than 30mmH₂The O column, because the cone angle of the inner cone-shaped concentrator and the cone angle of the outer cone-shaped concentrator are less than 2 multiplied by 30 degrees and the flow equalizing holes 13 are fully arranged on the cone surface, the local one-time wind speed can not be obviously increased, therefore, the abrasion problem of the cone-shaped concentrator can be effectively solved by utilizing the prior art.

Further, with particular reference to FIG. 2, the diffusion angle A of the diffuser ring 11₃Is 35 degrees, the diffuser ring 11 is a divergent ring body, and the diffusion angle A is₃Is the included angle between the extension surface of the contraction end of the gradually-expanded ring body and the axis thereof.

In the preferred embodiment, the divergence angle A₃The preferred angle of (3) is 30 °.

Further, referring specifically to fig. 2, the inner primary air duct 2 has an inner diameter D₁The distance between the bottom port of the inner cone-shaped concentrator 6 and the bottom port of the inner adapter ring 10 is H₁And H is₁＝K₁D₁，K₁Is a coefficient, K₁The value of (a) is in the range of 0.5 to 1.

In the preferred embodiment, the inner primary air rich pulverized coal airflow ring needs to pass through a distance to continuously perform inertial separation and strengthen ignition and stable combustion of rich-lean combustion and low NOx emission performance by utilizing gas-solid inertia difference, and simultaneously, the distance is the distance H between the bottom port of the inner cone-shaped concentrator 6 and the bottom port of the inner adapter ring 10 to prevent the concentrator from possible high-temperature corrosion or ablation₁。

Further, referring specifically to fig. 2, the inner diameter of the outer primary air duct 4 is D₂The distance between the bottom port of the outer cone concentrator 7 and the bottom port of the outer adapter ring 12 is H₂And H is₂＝K₂D₂，K₂Is a coefficient, K₂The value of (a) is in the range of 0.5 to 1.

In the preferred embodiment, the outer primary air rich pulverized coal airflow ring needs to pass through a certain distance to continue to perform inertial separation and strengthen ignition and stable combustion and low NOx emission performance of rich-lean combustion by utilizing gas-solid inertia difference, and simultaneously, the distance is the distance between the bottom port of the outer conical concentrator 7 and the outer adapting ring 12 so as to prevent the concentrator from being corroded or ablated at high temperature possiblySpacing H between bottom ports₂。

Further, referring to fig. 1 and fig. 2, the preferable proportion (25-30)%, of the pulverized coal airflow, introduced into the inner primary air inlet 2-1 and the outer primary air inlet 4-1 is as follows: (75-70)%; the preferable proportion (25-30)% of air introduced into the inner secondary air pipe 3 and the outer secondary air pipe 5 is as follows: (75-70)%.

Further, referring to fig. 2 specifically, when the coal quality introduced into the inner primary air inlet 2-1 and the outer primary air inlet 4-1 is the same, the coal introduced into the inner primary air inlet and the outer primary air inlet is easy-to-fire coal, high-quality coal, mixed coal of the easy-to-fire coal and the difficult-to-fire coal, mixed coal of the easy-to-fire coal and the low-quality coal, mixed coal of the high-quality coal and the difficult-to-fire coal or mixed coal of the high-quality coal and the low-;

when the coal quality introduced into the inner primary air inlet 2-1 and the outer primary air inlet 4-1 is different, the coal introduced into the inner primary air inlet 2-1 is easily-fired coal or high-quality coal, and the coal introduced into the outer primary air inlet 4-1 is difficultly-fired coal, low-quality coal or mixed coal of the difficultly-fired coal and the low-quality coal.

Under the condition that the inner primary air pulverized coal airflow is easy-to-fire coal or high-quality coal and the outer primary air pulverized coal airflow is difficult-to-fire coal or low-quality coal, diffusion type mixed combustion can be implemented with high performance, and because the inner primary air pulverized coal airflow and the inner secondary air can independently form a high-efficiency low NOx cyclone burner (inner vortex), low-load high-performance operation of the easy-to-fire coal or the high-quality coal can be safely implemented under the load of 25-30%, and at the moment, the low-load operation can be safely implemented only by stopping the supply of the outer primary air pulverized coal airflow and the outer secondary air in theory; generally, the swirl strength of the inner vortex is greater than that of the outer vortex, and the axial speed of the outer vortex is greater than that of the inner vortex, so that the inner vortex is equivalent to a fluid bluff body of multiphase flow relative to the outer vortex by adjusting inner secondary air and outer secondary air, and the stable combustion performance is favorably improved.

Further, referring specifically to fig. 3 and 4, the radial section of the tapered cone is circular, rectangular or square; the radial section of the divergent taper pipe is round, rectangular or square.

Further, with particular reference to figures 2 to 4,

when the inner cone type concentrator 6 is of a tapered typeWhen the conical pipe is fixed on the inner wall of the inner primary air pipe 2, when the inner conical concentrator 6 is a gradually expanding conical pipe, the conical pipe is fixed on the outer wall of the central pipe 1, and the external diameter of the opening end of the inner conical concentrator 6 is smaller than the internal diameter D of the inner primary air pipe 2₁；

When the inner conical concentrator 6 is a tapered conical pipe, the bottom port of the inner conical concentrator is used as a tapered end, and the top port of the inner conical concentrator is used as an open end;

when the inner conical concentrator 6 is a gradually expanding conical pipe, the bottom port of the inner conical concentrator is used as an open end, and the top port of the inner conical concentrator is used as a contracted end;

when the outer conical concentrator 7 is a tapered conical pipe, the outer conical concentrator is fixed on the inner wall of the outer primary air pipe 4, the bottom port of the outer conical concentrator 7 serves as a contracted end, the top port serves as an open end, and the inner diameter of the contracted end is larger than the outer diameter of the inner secondary air pipe 3;

and (III) when the outer conical concentrator 7 is a divergent conical pipe, the outer conical concentrator is fixed on the outer wall of the inner secondary air pipe 3, the bottom port of the outer conical concentrator 7 serves as an open end, and the top port serves as a contracted end, wherein the outer diameter of the open end is smaller than the inner diameter of the outer primary air pipe 4.

Further, referring specifically to FIGS. 3 to 4, the open end inside diameter D 'of the tapered cone'₃And the inner diameter D' of the contracted end₃The ratio range of (A) is 10: 7 to 10: 8;

beginning inner diameter D 'of divergent cone pipe'₄And the inner diameter D' of the contracted end₄The ratio range of (A) is 10: 7 to 10: 8.

Furthermore, the high-efficiency low-NOx double-vortex-flow pulverized coal burner can be horizontally, vertically or obliquely arranged on the combustion equipment. When the inner secondary air and the outer secondary air are direct currents, the high-efficiency low-NOx double-vortex-flow pulverized coal burner is a direct-current pulverized coal burner.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.

Claims (10)

1. The high-efficiency low-NOx double-vortex-flow pulverized coal burner is characterized by comprising a central pipe (1), an inner primary air pipe (2), an inner secondary air pipe (3), an outer primary air pipe (4) and an outer secondary air pipe (5) which are coaxially arranged from inside to outside in sequence, wherein the top ports of the inner primary air pipe (2), the inner secondary air pipe (3), the outer primary air pipe (4) and the outer secondary air pipe (5) are sealed, and the bottom ports are communicated; the device also comprises an inner cone-shaped concentrator (6), an outer cone-shaped concentrator (7), a radial swirler (8) and an axial swirler (9);

the top port of the central pipe (1) extends out of the top port of the inner primary air pipe (2), and the central pipe (1) is used for introducing air;

the side walls of the inner primary air pipe (2), the inner secondary air pipe (3), the outer primary air pipe (4) and the outer secondary air pipe (5) are respectively provided with an inner primary air inlet (2-1), an inner secondary air inlet (3-1), an outer primary air inlet (4-1) and an outer secondary air inlet (5-1), and the coal quality of the pulverized coal airflow introduced by the inner primary air inlet (2-1) and the outer primary air inlet (4-1) is the same or different;

the inner secondary air inlet (3-1) and the outer secondary air inlet (5-1) are used for introducing air;

the inner conical concentrator (6) is arranged in a channel enclosed by the inner wall of the inner primary air pipe (2) and the outer wall of the central pipe (1) and is used for carrying out concentration separation on the pulverized coal airflow introduced into the inner primary air pipe (2);

the outer conical concentrator (7) is arranged in a channel defined by the outer wall of the inner secondary air pipe (3) and the inner wall of the outer primary air pipe (4) and is used for carrying out concentration separation on the pulverized coal airflow introduced into the outer primary air pipe (4);

the radial swirler (8) is used for radially swirling air introduced into the inner secondary air pipe (3);

the axial cyclone (9) is used for axially swirling air introduced into the external secondary air pipe (5).

2. A high efficiency low NOx double swirl pulverized coal burner according to claim 1, further comprising an inner adapter ring (10), the inner adapter ring (10) being in communication with the bottom port of the inner primary air duct (2) through a diffuser ring (11).

3. A high efficiency low NOx double swirl pulverized coal burner according to claim 1, further comprising an outer adapter ring (12), the outer adapter ring (12) being in communication with the bottom port of the outer primary air duct (4) through another diffuser ring (11).

4. The high-efficiency low-NOx double-vortex-flow pulverized coal burner as claimed in claim 1, wherein the inner cone-shaped concentrator (6) and the outer cone-shaped concentrator (7) are both realized by tapered cone pipes or tapered cone pipes, the inner cone-shaped concentrator (6) and the outer cone-shaped concentrator (7) are vertically provided with a plurality of layers of flow equalizing channels in the circumferential direction along the side wall of the inner cone-shaped concentrator, and each layer of flow equalizing channel comprises a plurality of flow equalizing holes (13);

the total flow area of the flow equalizing holes (13) on the inner cone concentrator (6) or the outer cone concentrator (7) is at least larger than the maximum flow area of the open end of the concentrator where the flow equalizing holes are located.

5. A high efficiency low NOx double vortex flow pulverized coal burner as claimed in claim 4,

when the inner conical concentrator (6) is a tapered conical pipe, the inner conical concentrator is fixed on the inner wall of the inner primary air pipe (2), when the inner conical concentrator (6) is a tapered conical pipe, the inner conical concentrator is fixed on the outer wall of the central pipe (1), and the outer diameter of the opened end of the inner conical concentrator (6) is smaller than the inner diameter D of the inner primary air pipe (2)₁；

When the inner conical concentrator (6) is a tapered conical pipe, the bottom port of the inner conical concentrator is used as a tapered end, and the top port of the inner conical concentrator is used as an open end;

when the inner conical concentrator (6) is a gradually expanding conical pipe, the bottom port of the inner conical concentrator is used as an open end, and the top port of the inner conical concentrator is used as a contracted end;

when the outer conical concentrator (7) is a tapered conical pipe, the outer conical concentrator is fixed on the inner wall of the outer primary air pipe (4), the bottom port of the outer conical concentrator (7) serves as a tapered end, the top port serves as an open end, and the inner diameter of the tapered end is larger than the outer diameter of the inner secondary air pipe (3);

and thirdly, when the outer conical concentrator (7) is a divergent conical pipe, the outer conical concentrator is fixed on the outer wall of the inner secondary air pipe (3), the bottom port of the outer conical concentrator (7) serves as an open end, the top port serves as a contracted end, and the outer diameter of the open end is smaller than the inner diameter of the outer primary air pipe (4).

6. The high efficiency low NOx double swirl pulverized coal burner of claim 4, wherein the taper angle of the tapered cone is A₁The taper angle is an acute angle formed by an extension surface of the tapered end of the tapered conical pipe and the axis of the tapered conical pipe, and the value range of the acute angle is 10-35 degrees;

divergent angle A of divergent cone₂The acute angle is formed by the extension surface of the reducing end of the gradually expanding taper pipe and the axis of the gradually expanding taper pipe, and the value range of the acute angle is 10-35 degrees.

7. A high efficiency low NOx double swirl pulverized coal burner as claimed in claim 2 or 3, characterized in that the diffusion angle a of the diffusion ring (11)₃Is 35 degrees, the diffusion ring (11) is a gradually expanded ring body, and the diffusion angle A is₃Is the included angle between the extension surface of the contraction end of the gradually-expanded ring body and the axis thereof.

8. A high efficiency low NOx double vortex flow pulverized coal burner as claimed in claim 2, characterized in that the inner primary air duct (2) has an inner diameter D₁The distance between the bottom port of the inner cone-shaped concentrator (6) and the bottom port of the inner adapter ring (10) is H₁And H is₁＝K₁D₁，K₁Is a coefficient, K₁The value of (a) is in the range of 0.5 to 1.

9. A high efficiency low NOx double vortex flow pulverized coal burner as claimed in claim 3, characterized in that the inner of the outer primary air duct (4)Diameter of D₂The distance between the bottom port of the outer cone concentrator (7) and the bottom port of the outer adapter ring (12) is H₂And H is₂＝K₂D₂，K₂Is a coefficient, K₂The value of (a) is in the range of 0.5 to 1.

10. A high efficiency low NOx double vortex flow pulverized coal burner as claimed in claim 1, characterized in that the bottom port of the inner adapter ring (10) extends out of the bottom port of the inner secondary air duct (3);

the central tube (1) penetrates through the inner conical concentrator (6), and the bottom port of the central tube extends out of the inner conical concentrator (6); and/or

When the coal quality introduced into the inner primary air inlet (2-1) and the outer primary air inlet (4-1) is the same, the coal introduced into the inner primary air inlet and the outer primary air inlet is easy to fire, high-quality coal, mixed coal of the easy-to-fire coal and the difficult-to-fire coal, mixed coal of the easy-to-fire coal and the low-quality coal, mixed coal of the high-quality coal and the difficult-to-fire coal or mixed coal of the high-quality coal and the low-quality coal;

when the coal quality introduced into the inner primary air inlet (2-1) and the outer primary air inlet (4-1) is different, the coal introduced into the inner primary air inlet (2-1) is easy-to-fire coal or high-quality coal, and the coal introduced into the outer primary air inlet (4-1) is difficult-to-fire coal, inferior coal or mixed coal of the difficult-to-fire coal and the inferior coal; and/or

The flow equalizing holes (13) on the two adjacent layers of flow equalizing channels on the inner cone-shaped concentrator (6) and the outer cone-shaped concentrator (7) are distributed in a staggered mode, and the number of the flow equalizing holes (13) on the two adjacent layers of flow equalizing channels is 2 times of the number of the flow equalizing holes.

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