CN104100971A

CN104100971A - Cyclone burner with primary air concentration separation function

Info

Publication number: CN104100971A
Application number: CN201410320828.5A
Authority: CN
Inventors: 宗晓辉; 杨燕梅; 张海; 吕俊复; 刘青; 郑平安
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2014-07-07
Filing date: 2014-07-07
Publication date: 2014-10-15
Anticipated expiration: 2034-07-07
Also published as: CN104100971B

Abstract

The invention discloses a cyclone burner with a primary air concentration separation function, and belongs to the technical field of pulverized coal burning equipment. The cyclone burner is mainly characterized in that an open U-shaped flow guide plate is additionally arranged at an outlet of an elbow of a primary air pipe, and a V-shaped core barrel, three groups of annular check blocks and a central partition barrel are sequentially arranged on a horizontal section of the primary air pipe. The front end of the V-shaped core barrel is connected with the U-shaped flow guide plate, and the three groups of annular check blocks and the central partition barrel are sequentially arranged at the tail end of the V-shaped core barrel along an airflow direction. The horizontal section of the primary air pipe is divided into an inner channel and an outer channel by the V-shaped core barrel. Airflow with thick pulverized coal and airflow with thin pulverized coal can be separated from each other by the central partition barrel and can be prevented from being mixed with each other again. Inner and outer secondary air cyclone blades are adjustable. The cyclone burner has the advantages that the cyclone burner is simple in structure, good concentration separation effects can be realized, the airflow with the thick pulverized coal can be uniformly distributed, stable burning and low NOx emission characteristics of the cyclone burner can be guaranteed, and the like.

Description

A kind of turbulent burner of a deep or light separation of wind

Technical field

The present invention relates to pulverized coal combustion, is a kind of step cyclone-burner, belongs to coal-dust combustion device.

Background technology

Vortex burner is widely used in coal-fired power station boiler, and the feature of traditional turbulent burner is: one time wind enters burner hearth with direct current or cyclone mode, and Secondary Air rotates into burner hearth from a wind outside.The strong rotation of air-flow, makes to produce a low-pressure area at core, forms radial and axial barometric gradient.Axial pressure gradient will make the flue gas of core along axis reverse flow, forms the backflow contrary with primary air flow direction near burner outlet, and the root that high-temperature flue gas is entrainmented to burner jet heats breeze airflow, makes it to catch fire.Vortex burner generally adopts wall formula arrangement, and the layout of large-sized station boiler turbulent burner often adopts opposed firing mode.Compared with the straight flow combustion mode of quadrangle tangential circle, there is not integral-rotation in the furnace flame of opposed firing swirl flow combustion mode, and degree of filling and the flow field uniformity of flame are easily adjusted, and cigarette temperature deviation and the flue gas flow deviation of furnace outlet horizontal flue are less.

Tradition turbulent burner can form in the section of catching fire the region that partial oxygen concentration is higher, easily produces partial flame temperature peak district, so compared with DC burner, the NO of traditional turbulent burner _xdischarge capacity is higher.In order to reduce NO _xdischarge capacity, can adjust on the one hand the air distribution of turbulent burner, overcome the problem that a Secondary Air mixes too early; On the other hand can be by adjusting a wind, by deep or light breeze airflow separation.

Secondary Air is divided into two strands or multiply air-flow, sends into gradually burner hearth and mix with a wind, realize the Researched of Air Staging Combustion Burning Pulverized Coal along jet direction, avoid the formation of local oxygen enrichment, high-temperature region, can control and reduce thermal NO _xwith fuel type NO _xgeneration.Conventionally burner all has elbow structure, and pulverized coal particle moves to elbow, under effect of inertia, will keep original motion state, in the straight length streamwise enrichment of a wind.Research discovery, pulverized coal particle can remain to burner outlet at the inertia concentration effect of elbow always.In addition,, by install block additional in an airduct, the devices such as deflector, also can realize the effect of deep or light separation by the inertia in particle flow process.But the excessive enrichment of coal dust meeting causes local oxygen quantity not sufficient, causes combustion instability, affects efficiency of combustion.

Summary of the invention

Characteristic and the Secondary Air classification combustion technology of utilizing elbow inertial separation, in the problem aspect NOx control, the object of the invention is to propose a kind of turbulent burner of a deep or light separation of wind for turbulent burner, to ensure smooth combustion and low NOx drainage.

Technical scheme of the present invention is as follows:

A kind of turbulent burner of a deep or light separation of wind, comprise an airduct with elbow, be arranged on oil gun airduct, inner second air pipe and the outer second air pipe in airduct one time, in inner second air pipe and outer second air pipe, be respectively equipped with inner second air swirl vane and outer second air swirl vane, it is characterized in that: described turbulent burner also contains open U-shaped deflector (3), V-type core cylinder, three groups of collar stops and middle septum cordis cylinder; Described open U-shaped baffle arrangement is in the elbow exit of an airduct; Described V-type core cylinder, three groups of collar stops and middle septum cordis cylinder are arranged in an airduct horizontal segment, and V-type core cylinder front end is connected with open U-shaped deflector, and an airduct horizontal segment is divided into inside and outside two passages; In an airduct of V-type core tube rear end, arrange successively three groups of collar stops 5 and middle septum cordis cylinder 10 along airflow direction.

Technical characterictic of the present invention is also: three groups of described collar stops 5 reduce gradually along the radius of air current flow direction, radius is followed successively by 350～390mm, 280～320mm and 255～295mm, is followed successively by 250～290mm, 490～530mm and 720～760mm apart from the distance of V-type core cylinder (4) rearmost end; The radius of middle septum cordis cylinder 10 is 240～280mm, and the position of distance outlet is 870-910mm.

In technique scheme, three groups of described collar stops are preferably 371mm, 300mm and 275mm successively along the radius of air current flow direction, are preferably successively 270mm, 507mm and 738mm apart from the distance of V-type core cylinder rearmost end; The radius of middle septum cordis cylinder is preferably 260mm, and the location optimization of distance outlet is 890mm.

The present invention has the following advantages and the technique effect of high-lighting: 1. a wind straight length is divided into inside and outside two cavitys by U-shaped deflector and V-type core cylinder, effectively inertia-responsive elbow bias pulverized coal air-flow separated.2. the coal dust that is arranged so that of three groups of collar stops shrinks to center, then diffusion to the periphery, is not only beneficial to being uniformly distributed of coal dust, and can effectively prevents local coal dust overrich phenomenon.3. middle septum cordis cylinder separates with thin airflow completely by dense strand, effectively prevents that dense strand of breeze airflow and light strand of breeze airflow from mixing once again.

Brief description of the drawings

Fig. 1 is the turbulent burner structure diagram of a deep or light separation of wind provided by the invention.

Fig. 2 is elbow and U-shaped deflector schematic diagram.

The airduct of 1-with elbow; 2-oil gun airduct; The open U-shaped deflector of 3-; 4-V core cylinder; 5-collar stop; 6-inner second air pipe; 7-inner second air swirl vane; 8-outer second air pipe; 9-outer second air swirl vane; Septum cordis cylinder in 10-.

Detailed description of the invention

Further illustrate principle of the present invention, concrete structure and embodiment below in conjunction with accompanying drawing.

Fig. 1 is the turbulent burner structure diagram of a deep or light separation of wind.This burner mainly comprises an airduct 1 with elbow, be arranged on oil gun airduct 2 in airduct, inner second air pipe 6, outer second air pipe 8, inner second air swirl vane 7, outer second air swirl vane 9, open U-shaped deflector 3, V-type core cylinder 4, three groups of collar stops 5 and middle septum cordis cylinders 10; Inner second air swirl vane 7 and outer second air swirl vane 9 are separately positioned in inner second air pipe 6 and outer second air pipe 8; Described open U-shaped deflector 3 is arranged in the elbow exit of an airduct 1; Described V-type core cylinder 4, three groups of collar stops 5 and middle septum cordis cylinder 10 are arranged in the horizontal segment of an airduct, and V-type core cylinder 4 front ends are connected with open U-shaped deflector, and airduct 1 horizontal segment is divided into inside and outside two passages; In an airduct of V-type core tube rear end, arrange successively three groups of collar stops 5 and middle septum cordis cylinder 10 along airflow direction.

Secondary Air enters burner by inner second air pipe 6 and outer second air pipe 8 respectively, and inside and outside secondary air channel all adopts circumferential air inlet.Inner second air swirl vane 7 and the equal adjustable deflection angle of outer second air swirl vane 9, change swirling number, flexible and convenient operation.A general mood of carrying coal dust is flowed through and is entered turbulent burner inside with an airduct 1 of elbow, in elbow, coal dust under effect of inertia an airduct top enrichment, but due to the existence of open U-shaped deflector 3, one time airduct elbow section is divided into upper and lower two parts, and approximately 1/3 coal dust is in the bottom motion of U-shaped deflector.In addition, approximately there is 1/4 coal dust to enter V-type core cylinder 4 inner passages, so just weakened the side effect that coal dust is only crossed separating/enriching at horizontal pipe top in the past.Subsequently, at V-core cylinder 4 ends, three groups of collar stops 5 are arranged continuously, form three channel designs of first shrinking the similar Venturi tube form spreading afterwards, the breeze airflow of enrichment can part spread to surrounding when by this region, play certain concentrated phase dilution effect, and be conducive to coal fines circumferential direction and be uniformly distributed.Arrange again afterwards middle septum cordis cylinder 10, by deep or light two strands of air-flows isolation, prevented from mixing again, dense outer light distribution in forming, then enters burner hearth, and even dense strand of coal dust entrainmented in swirl secondary air, mix with backflow flue gas, play steady combustion and fall the target of low NOx drainage.

Three groups of collar stops of the present invention and an airduct horizontal segment are coaxially arranged, and along air current flow direction, radius is followed successively by 350～390mm, 280～320mm and 255～295mm, and preferably radius is 371mm successively, 300mm and 275mm; Distance apart from V-core cylinder rearmost end is followed successively by 250～290mm, 490～530mm, and 720～760mm, preferred distance is 270mm successively, 507mm and 738mm; The radius of middle septum cordis cylinder is 240～280mm, and preferably radius is 260mm; The position of distance outlet is 870-910mm, and preferred distance is 890mm.

Claims

1. the turbulent burner of the deep or light separation of wind once, comprise an airduct (1) with elbow, be arranged on oil gun airduct (2), inner second air pipe (6) and the outer second air pipe (8) in airduct one time, in inner second air pipe (6) and outer second air pipe, be respectively equipped with inner second air swirl vane (7) and outer second air swirl vane (9), it is characterized in that: described turbulent burner also contains open U-shaped deflector (3), V-type core cylinder (4), three groups of collar stops (5) and middle septum cordis cylinder (10); Described open U-shaped deflector (3) is arranged in the elbow exit of an airduct (1); Described V-type core cylinder (4), three groups of collar stops (5) and middle septum cordis cylinder (10) are arranged in an airduct horizontal segment, V-type core cylinder (4) front end is connected with U-shaped deflector, and an airduct (1) horizontal segment is divided into inside and outside two passages; In an airduct of V-type core tube rear end, arrange successively three groups of collar stops (5) and middle septum cordis cylinder (10) along airflow direction.

2. the turbulent burner of an a kind of deep or light separation of wind according to claim 1, it is characterized in that: described three groups of collar stops (5) reduce gradually along the radius of air current flow direction, radius is followed successively by 350～390mm, 280～320mm and 255～295mm, be followed successively by 250～290mm, 490～530mm and 720～760mm apart from the distance of V-type core cylinder (4) rearmost end; The radius of middle septum cordis cylinder (10) is 240～280mm, and the position of distance outlet is 870-910mm.

3. according to the turbulent burner of a claim 2 a kind of deep or light separation of wind according to claim 1, it is characterized in that: described three groups of collar stops (5) are followed successively by 371mm, 300mm and 275mm along the radius of air current flow direction, be followed successively by 270mm, 507mm and 738mm apart from the distance of V-type core cylinder (4) rearmost end; The radius of middle septum cordis cylinder (10) is 260mm, and the position of distance outlet is 890mm.