CN101865462B

CN101865462B - Weak-cyclone primary air multi-stage separation cyclone burner

Info

Publication number: CN101865462B
Application number: CN2010102008457A
Authority: CN
Inventors: 张海; 吴玉新; 郑平安; 刘青; 吕俊复; 杨海瑞
Original assignee: Tsinghua University
Current assignee: TAIYUAN BOILER GROUP CO Ltd; Tsinghua University
Priority date: 2010-06-09
Filing date: 2010-06-09
Publication date: 2012-01-18
Anticipated expiration: 2030-06-09
Also published as: CN101865462A

Abstract

The invention discloses a weak-cyclone primary air multi-stage separation cyclone burner and belongs to coal power combustion equipment and combustion technology. The cyclone burner is characterized in that: an open guiding bend and a core cylinder are arranged in a primary air pipe with a bend; the core cylinder divides the horizontal section of the primary air pipe into an inner channel and an outer channel; and one end of the core cylinder is connected with the guiding bend. The guiding bend is arranged at the bend of the primary air pipe and arranged in the same direction as the bend of the primary air pipe; a primary air swirl vane is arrange between an outer wall of the core cylinder and an inner wall of the primary air pipe, so that concentrated coal powder generates airflow with low swirling number. The weak-cyclone primary air multi-stage separation cyclone burner performs inertia separation on the coal powder by using the bend and uniformly distributes the concentrated coal powder on the primary air pipe close to the wall by using the weak-cyclone primary air. The weak-cyclone primary air multi-stage separation cyclone burner has the advantages of simple structure, good effect of concentration separation, uniform distribution of the concentrated coal powder, and the like. Therefore, the stable combustion and low NOx emission properties of the cyclone burner are guaranteed, and the cyclone burner is particularly suitable for fuel lean coal.

Description

A kind of Weak-cyclone primary air multi-stage separation cyclone burner

Technical field

The present invention relates to a kind of classification turbulent burner, belong to coal-dust combustion device and combustion technology.

Background technology

Vortex burner is widely used in the coal dust firing station boiler, and it is even to have the interior thermic load of stove, and thermal deviation is little, low NO _xAdvantages such as discharging.At present in the turbulent burner, coal dust is carried out deep or light separation extensively be employed in the way that wind straight length installs devices such as baffle, baffle plate additional, utilize particle inertia to reach deep or light separating effect, but burner structure is complicated, manufacturing cost is higher; Scroll casing type vortex burner then adjusting function is relatively poor.In the actual industrial production, need simple in structurely, easy to operate, and surely fire effectively, guarantee low NO _xThe turbulent burner of discharging.

Because burner generally has elbow structure, movement of particles to elbow will keep original track under effect of inertia, and in the former flow direction enrichment in edge of burner straight length.Correlative study shows that particle will remain to the burner outlet place at the inertia concentration effect of elbow always.Effectively utilize the elbow concentration effect of coal dust, both can reach coal dust is carried out deep or light separation purpose, also can reduce the structures such as baffle, baffle plate of burner direct current section, thereby simplify burner structure, reduce manufacturing cost.Yet when utilizing elbow that coal dust is separated, coal dust will be concentrated under effect of inertia and be enriched in the elbow top, and coal dust is crossed separating/enriching can cause the local hypoxgia of giving, and causes combustion instability.

Summary of the invention

For effectively utilizing elbow inertial separation characteristic, simplify the vortex burner structure, the objective of the invention is to propose a kind of Weak-cyclone primary air multi-stage separation cyclone burner.

Technical scheme of the present invention is following:

A kind of Weak-cyclone primary air multi-stage separation cyclone burner; Comprise an airduct being with elbow, be arranged on the oil gun airduct in the airduct one time, be arranged on the outer interior secondary air channel of airduct one time; Interior secondary wind swirl vane; Outer secondary wind stator and outer secondary air channel, it is characterized in that: in an airduct of described band elbow, install open water conservancy diversion elbow and core tube additional, the core tube is divided into inside and outside two passages with an airduct horizontal segment; Described open water conservancy diversion elbow links to each other with an end of core tube, and is installed at the airduct elbow one time, and arranges in the same way with the elbow of an airduct; And between core drum outer wall and an airduct inwall, be furnished with the wind swirl vane one time.

The length of blade of a wind swirl vane of the present invention is 20～40cm, is preferably 30cm; The blade number is 4～16, is preferably 6; The scope of the angle β of projection of swirl vane cross section and core bucket bus is 3 °＜β＜30 °, and angle β is preferably β=5; The scope that produces swirling number S is 0.05＜S＜0.5., be preferably S=0.08.

The cross section of open water conservancy diversion elbow of the present invention is open circular arc or polygon.

The present invention has the following advantages and the high-lighting effect: 1. utilize an airduct elbow particle action of inertia to reach separating effect, form inboard light strand and the dense strand of wind breeze airflow in the outside, simple in structure, effect is obvious.2. outer wind installs swirl vane additional, has alleviated the phenomenon of particle in the enrichment of elbow top, makes dense strand of pulverized coal particle under the vortex gas-flow effect, be thrown toward the airduct wall one time, and evenly distributes, and guarantees steady combustion and low nitrogen burning effect.3. the core tube is divided into inside and outside two cavitys with an airduct road straight length, effectively prevents the blending again of dense thigh and thin airflow.

Description of drawings

Fig. 1 is a Weak-cyclone primary air multi-stage separation cyclone burner structural principle sketch provided by the invention.

Fig. 2 is the layout sketch map of a wind swirl vane.

Airduct of elbow of 1-band; 2-oil gun airduct; The open water conservancy diversion elbow of 3-; 4-core bucket; Wind swirl vane of 5-; Secondary air channel in the 6-; Secondary wind swirl vane in the 7-; The outer secondary wind stator of 8-; The outer secondary air channel of 9-.

The specific embodiment

Further specify principle of the present invention, concrete structure and preferred forms below in conjunction with accompanying drawing.

Fig. 1 is the Weak-cyclone primary air multi-stage separation cyclone burner structure diagram.This burner mainly comprises airduct 1 of elbow of band; Oil gun airduct 2, interior secondary air channel 6, interior secondary wind swirl vane 7; Outer secondary wind stator 8; Outer secondary air channel 9, and be installed in open water conservancy diversion elbow 3, core bucket 4 and the outer wind swirl vane 5 that is fixed on core bucket outer wall in the airduct 1 one time.Secondary wind gets into turbulent burner by outer secondary air channel 9 and interior secondary air channel 6 respectively, the outer secondary wind swirling number of outer secondary wind stator 8 scalable, the distinguished and admirable thigh of interior secondary that interior secondary wind swirl vane 7 produces strong swirling number.Wind of powder feeding gets into turbulent burner through the airduct 1 of band elbow, and in the elbow, coal dust is enriched in airduct outside wall surface of level under the drainage of inertia and open water conservancy diversion elbow 3, thus form in airduct powder outer dense in light distribution.For avoiding coal dust to get in the core tube; And effectively utilize the inertia of coal dust in the elbow; Open water conservancy diversion elbow 3 is arranged in the airduct elbow one time, and arranges in the same way that with an airduct elbow cross section of open water conservancy diversion elbow is open circular arc or polygon; Also can be other forms, to guarantee that coal dust is enriched in the elbow top of an airduct and the bottom of open water conservancy diversion elbow 3 outside wall surface under effect of inertia.Core tube 4 is in airduct of level; One end of core bucket 4 is connected with open water conservancy diversion elbow 3; With airduct horizontal segment be divided into inside and outside two passages and; Wind of incoming flow and enrichment coal dust physically are being divided into deep or light two strands, and core tube 4 inboards are light strand of wind, and core tube 4 outsides are dense strand of wind.Introduce oil gun wind when oil gun airduct 2 is lighted a fire for burner, burner is only introduced a small amount of secondary wind after starting.

Because the elbow effect of inertia, the coal dust in dense strand of air-flow is with Local enrichment wind channel roof outside, and this phenomenon will remain to coal dust always and get into burner hearth; Because coal dust is crossed separating/enriching; Cause local oxygen supply not enough easily, cause combustion instability, problems such as efficiency of combustion reduction.For eliminating the too influence of enrichment of coal dust, between airduct 1 inwall of core tube 4 outer walls and band elbow, be furnished with wind eddy flow leaf 5 one time near the elbow.Behind band coal powder two-phase flow process swirl vane 5; Coal dust is because the centrifugal action of eddy flow is thrown toward wall; Thereby dense strand coal dust obtains further concentrating at wall, and original coal dust is crossed the phenomenon of separating/enriching and also weakened greatly because of the eddy flow centrifugal motion of coal dust at the top.When a wind was eddy flow, coal dust spread because of centrifugal action at burner outlet, can weaken the effect that concentration coal burner suppresses nitrogen oxide.For eliminating this side effect, the swirling number (ratio of tangential momentum flux and axial momentum flux) of a wind is controlled within limits.Simultaneously, swirling number is excessive, also can cause coal dust excessive to the abrasive action of swirl vane 5.Based on above reason, the effect of a wind swirl vane 5 is the air-flows that produce low swirling number, will avoid simultaneously wearing and tearing.For this reason, the design feature of swirl vane 5 is that length of blade is big, is generally 20～40cm, is good with 30cm; The blade number is few, is generally 4～16, is good with 6; The scope of the angle β of swirl vane 5 cross section projections and core bucket bus is 3 °～30 °, is good with 5 °.These characteristics of swirl vane 5 can reduce the wearing and tearing of coal dust to swirl vane to the full extent, and produce lower swirling number S, and its scope is 0.05～0.5.Behind dense strand of coal dust process swirl vane 5, will produce weak rotational gas flow, under weak rotational gas flow centrifugal action, coal dust is thrown toward wall, and is uniformly distributed in the airduct wall one time.A little less than further reducing, revolve a wind to the burner outlet influence on flow field, swirl vane 5 need be installed in the core tube near the elbow side.A little less than revolve dense strand wind and leave swirl vane 5 after because the dissipation effect swirling number weakens gradually, during to the exit, a little less than revolve dense strand of wind and can ignore the influence of revolving secondary wind by force.The dense strand of coal dust that is uniformly distributed with will be entrainmented high temperature and revolved by force in the secondary wind, mix with the backflow high-temperature gas, and coal dust firing is stable, and reach low NO _xThe target of discharging.

Claims

1. a Weak-cyclone primary air multi-stage separation cyclone burner comprises an airduct (1) of being with elbow, is arranged on the oil gun airduct (2) in the airduct one time; Be arranged on the outer interior secondary air channel (6) of airduct one time; Interior secondary wind swirl vane (7), outer secondary wind stator (8) and outer secondary air channel (9) is characterized in that: in an airduct (1) of described band elbow, install open water conservancy diversion elbow (3) and core tube (4) additional; Core tube (4) is divided into inside and outside two passages with an airduct (1) horizontal segment; Described open water conservancy diversion elbow links to each other with an end of core tube, and is installed at an airduct (1) elbow, and arranges in the same way with the elbow of an airduct (1); And between core tube (4) outer wall and an airduct (1) inwall, be furnished with a wind swirl vane (5) near the elbow.

2. a kind of Weak-cyclone primary air multi-stage separation cyclone burner as claimed in claim 1 is characterized in that: the length of blade of a described wind swirl vane (5) is 20～40cm, and the blade number is 4～16; The scope of the angle β of a wind swirl vane (5) cross section projection and core tube (4) bus is 3 °＜β＜30 °, and the scope that produces swirling number S is 0.05＜S＜0.5.

3. a kind of Weak-cyclone primary air multi-stage separation cyclone burner as claimed in claim 2; It is characterized in that: the number of a described wind swirl vane is 6; Length of blade is 30cm; Angle β=5 of the bus of a wind swirl vane (5) cross section projection and core tube (4) °, the generation swirling number is S=0.08.

4. like claim 1,2 or 3 described a kind of Weak-cyclone primary air multi-stage separation cyclone burners, it is characterized in that: the cross section of said open water conservancy diversion elbow is open circular arc or polygon.