CN106090907A

CN106090907A - A Premixed Strong Swirl Flame Diffusion Burner

Info

Publication number: CN106090907A
Application number: CN201610409210.5A
Authority: CN
Inventors: 王建臣; 陈启典; 张岩; 林宇震; 张弛
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2016-06-12
Filing date: 2016-06-12
Publication date: 2016-11-09
Anticipated expiration: 2036-06-12
Also published as: CN106090907B

Abstract

The invention discloses the strong swirl flame diffusion burner of a kind of premix, use the structure design of center classification, by combustion box, air pipe line, fuel conduit, cyclone, pre-combustion grade airport, pre-combustion grade nozzle and main combustion stage nozzle are constituted；Air pipe line uses with combustion box import and is welded to connect, and is used for guiding air through turbulent burner, burns in entering combustion chamber；Fuel gas is fed separately into pre-combustion grade and main combustion stage nozzle by fuel conduit, wherein the fuel of 25% 40% is injected directly into combustion chamber after entering pre-combustion grade nozzle, blend with the pre-combustion grade air being directly entered combustion chamber by pre-combustion grade airport, be diffused burning；The structure of the premix strong swirl flame diffusion that the present invention uses, is conducive to expanding fired downstream area, increases heating region, thus realize the burner that usable floor area is less, it is possible to heating greater room scope, improve efficiency of combustion simultaneously, reduce the discharge of pollutant.

Description

The strong swirl flame diffusion burner of a kind of premix

Technical field

The present invention relates to turbulent burner, particularly to the strong swirl flame diffusion burner of one premix.

Background technology

Coal, oil, the burning of natural gas are the thermal power sources of each department of national economy, utilize this chemistry of burning Reaction, the various burners obtaining heat energy from fuel are also widely used in various metal smelt, boiler sets Industry and the civil areas such as standby and scientific experiment, in burner, the structure design of burner is to obtain good combustion effect Principal element, which determines the flame distribution in the ignition performance of burner and flow field and Temperature Distribution, for burning dress The safe operation put and economic benefit have very important effect.

The at present burner for boiler plant and the thermal source of large heat exchanger, mostly use turbulent burner this Mechanism designs, this be due to its mixing being capable of efficient hardening fuel and air and high-temperature combustion product and unburned fuel under Stream flow field in mixed process, and its formed recirculating zone be maximally efficient, can as stable incendiary source, so The different field such as the burning of coal dust and fuel gas and gas turbine are widely used.

Now with many for the improvement of turbulent burner, mostly concentrate on to reduction NO_xDischarge, and flame stabilization Some researchs, when the bigger situation in the space needing combustion heating, the methods that the overwhelming majority uses just are to increase cyclone combustion The quantity of burner, if it is possible to designing a kind of cyclone head can be able to make very big at the cyclone structure using reduced size The temperature of surface area raises, then can simplify burner, reduces maintenance cost, improves operational efficiency.

Premixed combustion can improve efficiency of combustion, and the effective flame intensity strengthening locality, if lean premixed also may be used To reduce NO_xDischarge capacity, meanwhile, premixed combustion also can expand combustion reaction occur scope.

The design concept of center classifying cyclone then derives from the design of combustion chamber in aero-engine, the rotation of center classification Stream device head, by changing local equivalent proportion, solves the ignition problem under the little operating mode of aero-engine and smolders when big operating mode Problem, and characteristics of flame when it is changed under two kinds of operating modes is also beneficial to the stable burning of downstream flame, if but thinking Expand combustion range downstream, when being allowed to for providing the lifting of wider flow field temperature, also tackle its structure and carry out one Fixed improvement.

In sum, the present invention is based on practical implementation, has used for reference the design philosophy of center classifying cyclone, design A kind of burner premixing the diffusion of strong swirl flame, after fuel gas and air sufficiently premix, passes through cyclone Form strong eddy flow, recirculating zone can be formed and stablize flame, expand fired downstream area simultaneously, increase heating region, thus realize The less burner of usable floor area, it is possible to heating greater room scope, improves efficiency of combustion simultaneously, reduces the row of pollutant Put.

Content of the invention

The technical problem to be solved in the present invention is: little the lacking of, heating surface (area) (HS little for existing turbulent burner combustion range Point, provides a kind of turbulent burner being provided that bigger heated perimeter, and the hydrocyclone structure of employing center classification gives full play to pre- Combustion level for igniting and the advantage of flame stabilization, fuel gas and air premix after through cyclone, can be effective Improve efficiency of combustion, reduce air pollution；The main combustion stage structure of center classifying cyclone is designed as strong cyclone structure, effectively increases The subtended angle that big premix gas spread in downstream, increases combustion range, and main combustion stage premix gas is lighted effect by pre-combustion grade flame, same When can efficiently solve main combustion stage ignition problem.

The technical solution adopted for the present invention to solve the technical problems: the strong swirl flame diffusion burner of a kind of premix, adopts With the structure design of center classification, overall employing stainless steel material, obtaining heat by carrying out burning to gaseous fuel, it is main Structure includes pre-combustion grade nozzle, cyclone, pre-combustion grade airport and main combustion stage nozzle, and combustion box, supply air Air pipe line, the fuel conduit of supply fuel and electric spark igniter；Air pipe line by welding by way of and combustion box It is attached, be used for guiding air through turbulent burner, burn in entering combustion chamber；Fuel is supplied by fuel conduit respectively Enter pre-combustion grade and main combustion stage nozzle；The fuel gas accounting for total amount 25%-40% enters pre-combustion grade nozzle, is injected directly into burning In room, in air pipe line, the air of 25%-40% is blended by pre-combustion grade airport and fuel, is diffused burning；? Opening aperture on the tube wall of fuel conduit, main combustion stage nozzle is connected with fuel conduit by welding, and remaining fuel is through main combustion stage Nozzle first premixes with the air in air pipe line, and the swirl vane on cyclone enters combustion chamber afterwards, carries out pre- Mixed burning；The eddy flow that main combustion stage air-flow produces can form recirculating zone for stable flame, and simultaneously strong eddy flow can increase air-flow The angle of flare in the flow field of downstream, expands combustible gas distribution area in a combustion chamber, may be implemented in and with cyclone diameter ratio be Burn in the combustion chamber of 4-6 times；Electric spark igniter extend into pre-combustion grade downstream by pre-combustion grade airport and nearby flows In Chang, electric spark igniter is lighted a fire after pre-combustion grade ignited fuel, is lighted the fuel of main combustion stage by pre-combustion grade flame transmission, Realize the startup of burner.

Wherein, described cyclone material is stainless steel, and overall diameter is 116-124mm, and core is annular, internal diameter For 25-29mm, external diameter is 65-75mm；Inner cylinder face is tapped for the connection with pre-combustion grade nozzle and fuel conduit；Cylindrical Having the prismatic blade that 10-16 is individual, thickness is 0.8-1.5mm to be uniformly distributed circumferentially on cylinder, being used for forming strong eddy flow, it designs rotation Fluxion is 0.8-1.0.

Wherein, described pre-combustion grade airport is positioned on the center anchor ring of cyclone, has 1-3 on center annular portion The through hole that circle is uniformly distributed circumferentially, direction is consistent with air-flow direction is as the circulation passage of pre-combustion grade air, and it is effective Area duty gas always flows the 25%-40% of effective area.

Wherein, described pre-combustion grade nozzle is one end open, the pipeline that one end is closed；The external diameter of open at one end is 25- 29mm, internal diameter is 17-21mm, tapped for being attached with cyclone outside it；1-3 is had on the end face of blind end Diameter, at the direct perforation of 1-2mm, has individual circumferentially all distribution, the diameters of 10-16 little in the direct projection of 1-2mm on its face of cylinder Hole, its opening direction is vertical with airflow direction.

Wherein, the material of described main combustion stage nozzle is stainless steel, is the L-type pipeline of one end open, and external diameter is 6-8mm, Internal diameter is 2-4mm；Open at one end is connected with the aperture on fuel conduit；Have and airflow direction on the face of cylinder at blind end 2-3 vertical diameter is at the direct projection aperture of 1-2mm；The height of main combustion stage nozzle is 16-20mm so that outlet direct perforation is in footpath It is directed at the middle part of swirler blades passage on position.

Wherein, the material of described fuel conduit is stainless steel, has 10-16 diameter at 2-in its upstream portion The aperture of 4mm connects with main combustion stage nozzle, and position of opening need to make the blade of the cyclone of distance foremost of main combustion stage nozzle have 6- 10mm；Front end is tapped, can be connected with pre-combustion grade nozzle by cyclone.

Wherein, the material of described air pipe line is stainless steel, a diameter of 120-130mm, is slightly larger than cyclone diameter, leaf Intercuspal space is 2-4mm, desirably prevents tempering, also allows for installing simultaneously.

Wherein, the ratio that described pre-combustion grade fuel accounts for total fuel is 25%-40%, and the effective area of pre-combustion grade flowing accounts for The ratio of total flowing effective area is 25%-40%.

Wherein, the leading portion of described combustion chamber is the taper that drift angle is 150 °-170 °, is used for reducing the flowing that sudden expansion brings Loss.

The operation principle of the present invention: burner is designed as pre-combustion grade and main combustion stage two by the thought utilizing center to be classified Point, wherein the fuel of 25%-40% burns in pre-combustion grade downstream, and the fuel of 60%-75% is carried out in the downstream of main combustion stage Burning, electric spark igniter then reaches pre-combustion grade downstream nearby by pre-combustion grade airport.The fuel of pre-combustion grade is by pre-combustion grade Nozzle is injected directly in combustion chamber, and pre-combustion grade air enters in combustion chamber through pre-combustion grade airport, due to pre-combustion grade Nozzle direction is vertical with air-flow direction, beneficially the quick blending of fuel and air, and blending is after entering combustion chamber Just occur, so the oil-gas ratio of local, pre-combustion grade downstream is high, beneficially being smoothed out of pre-combustion grade ignition process, once pre-burning Level is lighted a fire successfully, just may utilize the flame successful ignition main combustion stage of pre-combustion grade, thus realizes the burning in whole basin.Main combustion stage is fired Material is ejected in air pipe line by main combustion stage nozzle and mixes with air, and mixed combustible gas entered cyclone blade and formed Strong eddy flow, enters the combustion chamber of a diameter of turbulent burner diameter 4-6 times, forms expansion air-flow, is ignited by pre-combustion grade, carry out pre- Mixed burning, it is achieved increase the purpose of combustion range in combustion chamber, the recirculating zone that simultaneously may also rely on the formation of strong eddy flow is stablized Flame；The center hierarchy of fuel gas premix can be effectively reduced the discharge of pollutant；Main combustion stage blade and tube wall it Between gap then can be effectively prevented main combustion stage and be tempered.

The present invention compared with prior art has the advantage that as follows:

(1) premix of the present invention strong swirl flame diffusion burner, main combustion stage is designed as strong eddy flow, can be effective in downstream Form the bigger expansion flowing of subtended angle, expand the combustion range in cyclone downstream, increase heating surface (area) (HS.

(2) the strong swirl flame diffusion burner of premix of the present invention have employed the design philosophy of center classification, beneficially point Fire, strong eddy flow can form recirculating zone, is conducive to stablizing of burning, adds fuel and sufficiently premix with air, be conducive to carrying High burning efficiency, can also reduce the generation of pollutant simultaneously.

(3) version of the strong swirl flame diffusion burner of premix of the present invention is simple, and easy to assembly, form of nozzle is easy In processing, be conducive to simplifying the overall structure of the device combustion parts such as boiler and storage heater, it is simple to operation and maintenance, applicable many Plant gaseous fuel, there is very wide fuel autgmentability.

Brief description

Fig. 1 is a kind of structural representation premixing strong swirl flame diffusion burner of the present invention；

Fig. 2 is the integrally-built trimetric drawing of the strong swirl flame diffusion burner of one premix of the present invention；

Fig. 3 is the schematic diagram of the pre-combustion grade nozzle of the present invention；

Fig. 4 is the hydrocyclone structure schematic diagram of the present invention；

Fig. 5 is the main combustion stage nozzle arrangements schematic diagram of the present invention；

In figure: 1 is pre-combustion grade nozzle, 2 is cyclone, and 3 is pre-combustion grade airport, and 4 is main combustion stage nozzle, and 5 is combustion chamber Casing, 6 is air pipe line, and 7 is fuel conduit, and 8 is electric spark igniter, and 9 is the first pad, and 10 is the second pad.

Detailed description of the invention

Below in conjunction with the accompanying drawings and detailed description of the invention is discussed in detail the present invention.

A kind of flame spread burner premixing strong eddy flow described in the present embodiment as shown in Figure 1, uses center classification Design structure, overall employing stainless steel material, wherein combustor section includes: pre-combustion grade nozzle the 1st, cyclone the 2nd, pre-combustion grade air Hole 3 and main combustion stage nozzle 4, and the 7th, the fuel conduit of supply fuel supply the air pipe line 6 of air, the electricity starting burner is fiery Spark lighter 8 and the casing 5 of combustion chamber carrying out combustion reaction process.Fuel gas is fed to device by fuel conduit 7 In, a part of fuel is entered directly in combustion chamber and by the pre-combustion grade air of pre-combustion grade airport 3 by pre-combustion grade nozzle 1 It is diffused burning；Remaining fuel enters in air pipe line 6 by main combustion stage nozzle 4, first premixes with incoming air, Blade through cyclone 2 afterwards, forms strong eddy flow in downstream, is diffused burning, and the recirculating zone that strong eddy flow is formed can realize Flame stabilization, forms diffusive gas flow simultaneously, increases the scope that combustible gas can reach.The start-up course of burner i.e. ignition process Being realized by electric spark igniter 8, igniter 8 produces high-temperature region and lights pre-combustion grade fuel, then relies on pre-combustion grade flame transmission point The combustible gas of combustion main combustion stage, it is achieved the startup of whole device.

As it is shown in figure 1, fuel conduit 7 and pre-combustion grade nozzle 1 are all connected with cyclone 2 by screw thread, it is achieved combustion The supply of material, seals equipped with the first pad 9 and the second pad 10 in junction, to prevent fuel from leaking；Fuel conduit 7 Upstream end has a 10-16 hole being uniformly distributed circumferentially at 2-4mm for the diameter, main combustion stage nozzle 4 by the form of welding with Aperture connection on fuel conduit 7, the position of aperture circumference should make the center of main combustion stage nozzle 4 rough alignment blade path； The igniting probe of electric spark igniter 8 passes through pre-combustion grade airport 3, reaches pre-combustion grade nozzle 1 downstream nearby；Air pipe line 6 Tube wall and the blade of cyclone 2 between there is tip clearance, it is simple to main combustion stage can also be effectively prevented while installation and send out Raw tempering.

As in figure 2 it is shown, air pipe line 6 is attached by way of welding with combustion box 5, air is guided to enter combustion Burn in room；The leading portion of combustion box 5 becomes drift angle the taper of 150 °-170 °, to reduce the loss that sudden expansion brings；This burner Can realize heating the space of a diameter of burner diameter 4-5 times.

As it is shown on figure 3, pre-combustion grade nozzle 1 one end open connects with fuel conduit 7, other one section is machined with the little of direct projection Hole；On end face, wherein there is 1-3, the diameter aperture at 1-2mm, be conducive to improving the local equivalent in pre-combustion grade center flow field Ratio, has 1-2mm direct projection aperture vertical with airflow direction, a diameter of on cylindrical side, and 10-16 is circumferentially uniformly divided altogether Cloth, fuel ejection is done transverse jet, can be accelerated the blending speed of air and fuel by aperture in atmosphere.

As shown in Figure 4, cyclone 2 is made up of annular section and the blade two parts at center；Blade is at center annular portion External cylindrical surface on be uniformly distributed circumferentially 10-16, be prismatic blade, thickness is 0.8-1.5mm, and design swirling number is 0.8- 1.0；On the inner cylinder face of the annular section at center tapped for connecting；Pre-combustion grade airport 3 is positioned at the center of cyclone 2 Annular section, has 1-3 on the direction flowed along air and encloses the through hole being circumferentially all distributed, and this design is by air pipe line Air divide into two parts, pre-combustion grade air and main combustion stage air, wherein pre-combustion grade air accounts for total 25%-40%, warp Cross pre-combustion grade airport 3 and enter combustion chamber, so the 25%-of the effective area of the through hole also total effective area of duty flow of air 40%；The installation site of cyclone 2 depends on fuel conduit 7, and the exit end face of cyclone 2 and combustion chamber 6 import should be made to put down Together.

As it is shown in figure 5, main combustion stage nozzle 4 is L-type, wherein one end open is for connecting with fuel conduit 7, opens for other one section , diameter vertical with air-flow direction by 2-3 is used for spraying fuel at the direct projection aperture of 1-2mm, this transverse jet Form contributes to the quick mixing of air and fuel；The height of nozzle should make to export the basic center being directed at blade path.

Claims

1. A premixed strong-swirl flame diffusion burner, characterized in that: it adopts a centrally graded structural design, and the whole is made of stainless steel, and obtains heat by burning gaseous fuel, and its main structure includes a pre-combustion nozzle (1) , swirler (2), pre-combustion stage air holes (3) and main combustion stage nozzles (4), as well as combustor case (5), air line for air supply (6), fuel line for fuel supply (7) and spark igniter (8); the air pipeline (6) is connected with the combustion chamber casing (5) by welding, and is used to guide the air to pass through the swirl burner and enter the combustion chamber for combustion; the fuel The pipeline (7) feeds the fuel into the pre-combustion nozzle (1) and the main combustion nozzle (4); the gaseous fuel, which accounts for 25%-40% of the total, enters the pre-combustion nozzle (1), and is directly injected into the combustion In the chamber, 25%-40% of the air in the air pipeline (6) is mixed with the fuel through the pre-combustion level air hole (3) to carry out diffusion combustion; small holes are opened on the pipe wall of the fuel pipeline (7) , the main combustion stage nozzle (4) communicates with the fuel pipeline (7) through welding, and the remaining fuel is pre-mixed with the air in the air pipeline (6) through the main combustion stage nozzle (4), and then passes through the cyclone (2) The swirl blades on the top enter the combustion chamber for premixed combustion; the swirl generated by the main combustion stage airflow can form a recirculation zone to stabilize the flame, and at the same time, the strong swirl can increase the expansion angle of the airflow in the downstream flow field, Enlarging the distribution area of the combustible gas in the combustion chamber can realize combustion in a combustion chamber whose diameter ratio is 4-6 times that of the swirler; the electric spark igniter (8) extends into the combustion chamber through the air hole (3) of the pre-combustion stage In the flow field not far downstream of the pre-combustion stage, the electric spark igniter (8) ignites the fuel of the pre-combustion stage, and then ignites the fuel of the main combustion stage through the propagation of the flame of the pre-combustion stage to realize the start-up of the burner.

2. A kind of premixed strong swirling flame diffusion burner according to claim 1, characterized in that: the material of the swirler (2) is stainless steel, the overall diameter is 116-124mm, and the central part is annular, The inner diameter is 25-29mm, and the outer diameter is 65-75mm; the inner cylindrical surface is tapped with threads for connection with the pre-combustion stage nozzle (1) and the fuel pipeline (7); there are 10-16 threads on the outer cylindrical surface, and the thickness Straight blades with a diameter of 0.8-1.5mm are evenly distributed along the circumference to form a strong swirl flow, and the design swirl number is 0.8-1.0.

3. A premixed strong swirl flame diffusion burner according to claim 1, characterized in that: said pre-combustion level air holes (3) are located on the central annular surface of the swirler, in the central annular part There are 1-3 circles of through holes evenly distributed along the circumference and in the same direction as the air flow direction as the circulation channel of the pre-combustion grade air, and its effective area accounts for 25%-40% of the total air flow effective area.

4. a kind of premixed strong swirl flame diffusion burner according to claim 1, is characterized in that: described pre-combustion stage nozzle is (1) one end opening, the pipeline of one end sealing; The external diameter of opening one end is 25-29mm, the inner diameter is 17-21mm, and the outer side is tapped with threads for connection with the cyclone (2); the end face of the closed end is provided with 1-3 direct holes with a diameter of 1-2mm, on the cylindrical surface There are 10-16 direct holes evenly distributed along the circumference, with a diameter of 1-2mm, and the opening direction is perpendicular to the airflow direction.

5. A kind of premixed strong swirling flame diffusion burner according to claim 1, characterized in that: the material of the main combustion stage nozzle (4) is stainless steel, which is an L-shaped pipeline with an open end, and the outer The diameter is 6-8mm, and the inner diameter is 2-4mm; one end of the opening is connected with the small hole on the fuel pipeline (7); there are 2-3 diameters perpendicular to the airflow direction on the cylindrical surface at the closed end. 2mm direct injection hole; the height of the main combustion stage nozzle (4) is 16-20mm, so that the outlet direct injection hole is aligned with the middle part of the swirler (2) vane passage on the radial position.

6. A kind of premixed strong swirl flame diffusion burner according to claim 1, characterized in that: the material of the fuel pipeline (7) is stainless steel, and there are 10-16 pieces in its upstream part A small hole with a diameter of 2-4mm communicates with the main combustion stage nozzle (4). The thread can be connected with the pre-combustion stage nozzle (1) through the swirler (2).

7. A premixed strong swirl flame diffusion burner according to claim 1, characterized in that: the material of the air pipeline (8) is stainless steel, with a diameter of 120-130mm, slightly larger than the swirler (2) Diameter, the blade tip clearance is 2-4mm, which is beneficial to prevent tempering and is also easy to install.

8. A kind of premixed strong swirl flame diffusion burner according to claim 1, characterized in that: the ratio of the pre-combustion level fuel to the total fuel is 25%-40%, the effective flow of the pre-combustion level The ratio of the area to the total flow effective area is 25%-40%.

9. A premixed strong swirling flame diffusion burner according to claim 1, characterized in that: the front section of the combustion chamber is conical with a vertex angle of 150°-170° to reduce sudden expansion resulting flow loss.