CN102954485A

CN102954485A - Long front arch and secondary air composite structure of lignite-fired traveling grate boiler

Info

Publication number: CN102954485A
Application number: CN2011102364738A
Authority: CN
Inventors: 董芃
Original assignee: GREEN ENVIRONMENTAL PROTECTION ENERGY SOURCE TECHNOLOGY Co Ltd OF HARBIN INSTITUTE OF TECHNOLOGY
Current assignee: GREEN ENVIRONMENTAL PROTECTION ENERGY SOURCE TECHNOLOGY Co Ltd OF HARBIN INSTITUTE OF TECHNOLOGY
Priority date: 2011-08-18
Filing date: 2011-08-18
Publication date: 2013-03-06

Abstract

The invention discloses a long front arch and secondary air composite structure of a lignite-fired traveling grate boiler. The structure comprises a traveling grate stoker, a lignite hopper, a single long front arch, composite secondary air exhaust pipes and a smoke guide arch, wherein the single long front arch is arranged inside a hearth from front to back, the composite secondary air exhaust pipes are arranged on a side wall of the hearth and positioned below the long front arch, and the smoke guide arch is used for guiding high-temperature smoke to an upper hearth. Lignite can be quickly ignited under the action of thermal radiation of the long front arch after being fed into the hearth along with the traveling grate stoker, and flame generated by combustion of the lignite and the high-temperature smoke skim through along an integral lignite bed of the traveling grate stoker from front to back and are discharged from a long front arch outlet positioned at the rear of the hearth, so that the integral lignite bed which is positioned below the long front arch and arranged on the traveling grate stoker is in a high-temperature state, and high combustion efficiency can be realized. Besides, air delivered by an air blower is sprayed into the upper side of the lignite bed positioned below the long front arch via the composite secondary air exhaust pipes, so that high-volatility matters in the lignite are guaranteed against generating black smoke due to oxygen deficiency during combustion.

Description

Use long face arch and the Secondary Air combining structure of brown coal chain grate boiler

Technical field

The present invention relates to field of boilers, be specially the long face arch and the Secondary Air combining structure that use the brown coal chain grate boiler.

Background technology

Brown coal have another name called the bavin coal, are the minimum colms of degree of coalification.Brown coal moisture is large, volatile matter is high, burning-point is low, be easy to catch fire, phosphorus content is low, low heat valve is low.In China, lignite resource mainly be distributed in east Inner Mongolia, YunnanThe east, northeast and South ChinaCertain reserves are also arranged.Because the combustion characteristics of above-mentioned brown coal, at present, boiler only has the coal dust firing of employing, fluid bed and reciprocal grate combustion system just can use brown coal.Traditional traveling-grate stoker combustion system adopts short face arch, long rear arch, face arch is higher than rear arch, the combined type furnace arch structure that flue gas is drawn at furnace front under the rear arch guiding, the brown coal high for volatile matter, that phosphorus content is low, when its volatile matter afterburnt, the burning of remaining carbon granules is not enough guarantees that the burner hearth under the rear arch has higher temperature, also just can not realize carbon granules in lime-ash efficient burning constantly in the burner hearth under the rear arch, cause ash content carbon high, this is not only so that efficiency of combustion is low, and can't guarantee the normal output of boiler.Therefore, up to the present, there is no the traveling-grate stoker combustion technology that can effectively use brown coal.

Traveling-grate stoker is a kind of widely used combustion system; its operation energy consumption is far below coal dust firing and fluidized bed combustion mode; its reliability of operation is then far above the reciprocal grate combustion system; therefore; use brown coal and apply with traveling-grate stoker if can realize; will promote the progress of brown coal combustion technology, energy savings and protection of the environment are had important practical significance.

Summary of the invention

Can not adapt to the combustion characteristics of brown coal and cause efficiency of combustion low and easily produce the problem such as black smoke for existing traveling-grate stoker.The invention provides and be suitable for long face arch and the Secondary Air combining structure of using traveling-grate stoker to use brown coal.Technical scheme of the present invention is: remove the forward and backward arch combining structure that the conventional chains fire grate adopts, adopt rear arch is not set, single long face arch from front to back only is set, and the burner hearth side wall in its underpart arranges the structure of combination Secondary Air in burner hearth.Brown coal are when entering burner hearth with fire grate, because its burning-point is low, can catch fire rapidly on the surface, coal seam.Because the present invention is provided with long face arch from front to back in burner hearth, under its guiding, brown coal burned flame and high-temperature flue gas will be along skimming over from front to back on the whole chain fire-gate coal seam, draw from the long face arch exit that is positioned at the burner hearth rear portion, so just guarantee to be positioned at whole chain fire-gate coal seam, long face arch bottom and all be in the condition of high temperature, guarantee the after-flame of carbon granules in the lime-ash, realized very high efficiency of combustion.Simultaneously, be provided with the combination Secondary Air jet pipe that is connected with secondary air duct in both sides, long face arch bottom, be used for guaranteeing that the high-volatile of brown coal can not produce because of anoxic black smoke in combustion process.

Description of drawings

Fig. 1 is the cutaway view of front view of the present invention

Fig. 2 is the cutaway view in the A-A cross section of Fig. 1

Piece number explanation among the figure:

1, traveling-grate stoker; 2, coal bunker; 3, Secondary Air jet pipe; 4, long face arch; 5, front smoke chamber; 6, upper furnace; 7, lead the cigarette arch; 8, left side convection bank flue; 9, right side convection bank flue; 10, air delivery duct; 11, burner hearth side wall; 12, boiler flue gas outlet, 13, slag notch.

The specific embodiment

Below in conjunction with accompanying drawing optimum implementation of the present invention is described in detail.Long face arch and the Secondary Air combining structure that uses the brown coal chain grate boiler comprises traveling-grate stoker 1, coal bunker 2, the secondary air channel 3 that is connected with air delivery duct 10, long face arch 4, leads cigarette arch 7.Be provided with the boiler body that includes working medium in heat transferred boiler left side convection bank flue 8 and right side convection bank flue 9, that be used for fuel combustion is produced on the top of air delivery duct 10.

During boiler operatiopn, brown coal in coal bunker 2 drop on the traveling-grate stoker 1, and along with the bottom that is entered into long face arch 4 by the traveling-grate stoker 1 that moves behind the forward direction, because the fugitive constituent of brown coal is high and burning-point is low, under the heat radiation effect of the long face arch 4 with higher temperature, the rapid ignition of surface, coal seam meeting, the flame that produces and high-temperature flue gas are under the guiding of long face arch 4, along skimming over from front to back on the whole chain fire-gate coal seam, draw from long face arch 4 exits that are positioned at the burner hearth rear portion, so just guarantee to be positioned at whole chain fire-gate coal seam, long face arch 4 bottoms and all be in the condition of high temperature, guaranteed the after-flame of carbon granules in the lime-ash, realized very high efficiency of combustion.The high-temperature flue gas of drawing from long face arch 4 exits that are positioned at the burner hearth rear portion will enter into upper furnace 6 under the guiding of leading cigarette arch 7, then flow through successively right side convection bank flue 9, front smoke chamber 5 and left side convection bank flue 8 from the rear portion of upper furnace 6, working medium in the boiler is heated, then discharge boiler by boiler flue gas outlet 12.Simultaneously, on the burner hearth side wall 11 of long face arch 4 bottoms, respectively be provided with the combination Secondary Air jet pipe 3 that is connected with air delivery duct 10, the air of being sent here by air delivery duct 10 by air blast sprays into the top, coal seam that is positioned at long face arch 4 bottoms by combination Secondary Air jet pipe 3, be used for guaranteeing that the high-volatile of brown coal can not produce because of anoxic black smoke in combustion process.The lime-ash that produces after the brown coal burning is discharged boiler from slag notch 13.

Claims

1. use the long face arch of brown coal chain grate boiler and Secondary Air combining structure and comprise traveling-grate stoker (1), coal bunker (2), the secondary air channel (3) that is connected with air delivery duct (10), long face arch (4) and lead cigarette arch (7), and in the air delivery duct boiler body that (10) top arranges, that include left side convection bank flue (8) and right side convection bank flue (9).

2. long face arch and the Secondary Air combining structure that uses the brown coal chain grate boiler according to claim 1, it is characterized in that being provided with on the top of traveling-grate stoker (1) the long face arch (4) that covers from front to back, and the burner hearth side wall 11 in long face arch (4) bottom is provided with the combination Secondary Air jet pipe (3) that is connected with air delivery duct (10).

3. long face arch and the Secondary Air combining structure that uses the brown coal chain grate boiler according to claim 1, the upper back that it is characterized in that long face arch (4) is provided with leads cigarette arch (7), long face arch (4) and lead between the cigarette arch (7) and leave the gap is used for guaranteeing that flue gas flows to upper furnace (6) from the rear portion of long face arch (4).