CN106642082B - A small cyclone melting pulverized coal furnace - Google Patents

Abstract

The present invention relates to a kind of small cyclones to melt coal-powder boiler, belongs to coal-dust combustion device field.A kind of small cyclones melting coal-powder boiler is by blade type turbulent burner, vortex melt-combustion room, high-temperature flue gas fairlead, secondary furnace and heat exchange burner hearth composition.Its lobular turbulent burner is made of as First air and coal dust mixing entrance shell and swirl vane, and is connected with vortex melt-combustion ceiling end；Vortex melt-combustion room top is each side disposed with the high temperature air entrance of a tangential tilt downward (tilt adjustable section), and lower part is slag notch；High-temperature flue gas fairlead is drawn by vortex melt-combustion ceiling portion middle position, and there are two tangential air intake vents in horizontal segment arrangement, high-temperature flue gas fairlead horizontal end is finally connected with secondary furnace through certain angle of expanding, secondary furnace top is heat exchange burner hearth, heat exchange burner hearth lining is equipped with heating surface, and high-temperature flue gas is in the progress heat exchange in burner hearth that exchanges heat.Present invention improves the small coal-powder boiler coal adaptability carried out at present is poor, fire box temperature is low, combustion instability and the high problem of unburned carbon in flue dust.

Description

A kind of small cyclones melting coal-powder boiler

Technical field

The present invention relates to coal-fired industry coal-powder boiler, specially small cyclones melt coal-powder boiler.

Background technique

The existing Industrial Boiler in China more than 50 ten thousand, wherein coal-burning boiler accounts for 85%, and middle and small burn coal boiler is general at present Mode is fired all over using layer, often there are the losses such as leakage coal, flying dust, smoke evacuation in combustion, thus operational efficiency is very low.Meanwhile Industry coal-boiler is the second largest coal-smoke pollution source in addition to station boiler, seriously polluted, is difficult to focus on.With environment Problem becomes increasingly conspicuous, and requirement of the relevant government department to the environmental protection aspect such as industry boiler energy-conservation emission reduction is also higher and higher, in view of China's richness coal, the resources characteristic of oil-poor, few gas are completely unrealistic at fuel-oil or fuel-gas boiler by boiler improvement.Thus, due to Small coal-powder boiler is efficient, and energy conservation, the advantage of emission reduction, the development of small-sized pulverized-coal fired boiler just seems necessary.Currently, passing through study moral The successful experience of the small pulverized-coal fired boiler of Guo Deng developed country, China Coal Research Institute have been developed that the height for possessing independent intellectual property right Pulverized-coal fired boiler is imitated, and is promoted on Shanxi, Liaoning and other places, effect is preferable.

But there is also some problems for the small pulverized-coal fired boiler promoted at present.Firstly, small pulverized-coal fired boiler require to use high volatile, High heating value, high ash melting point, weak caking property, the low water of low-sulfur low ash high-quality bituminous coal, i.e., top quality III class bituminous coal can only be burnt, to coal Matter it is more demanding；Simultaneously as furnace water cooling degree is larger, cause fire box temperature lower, burns more unstable；Moreover, because Burner hearth is smaller, and flame travel falls short of, without enough tail-off times, cause CO amount remaining in unburned carbon in flue dust and flue gas compared with Height, to reduce the boiler efficiency of small pulverized-coal fired boiler.

Therefore, in order to promote the use of small coal-powder boiler, its technological merit is utilized, it is necessary to pass through some structure changes and operation side The change of formula is to overcome above-mentioned disadvantage.

Summary of the invention

The purpose of the present invention is the changes by separation and Boiler Operation on burning and heat exchange structure, to overcome mesh The problems such as coal quality requirements existing for preceding small pulverized-coal fired boiler are high, combustion instability, unburned carbon in flue dust is high, while further attempting to reduce The discharge of NOx keeps its more environmentally-friendly reliable.

The technical solution adopted by the present invention is that: small cyclones melting coal-powder boiler includes blade type turbulent burner, and whirlwind is molten Melt combustion chamber, high-temperature flue gas fairlead, secondary furnace and heat exchange burner hearth.When operation, First air carries coal dust and is fired by blade type eddy flow Burner is fed by whirlwind melt-combustion ceiling portion spiral；Tangential high temperature air is provided at left and right sides of the top of whirlwind melt-combustion room Entrance, high temperature air are equivalent to tangential Secondary Air, into combustor ignition coal dust, form high temperature fused state；Combustion chamber lower part It is provided with slag notch, slag is flowed down along wall surface and is thus discharged.High-temperature flue gas fairlead is drawn by top of combustion chamber middle position, coal The high-temperature flue gas that powder burning generates imports secondary furnace through fairlead, eventually enters into heat exchange burner hearth, and wherein fairlead horizontal segment is arranged There is tangential air port, thus appropriate flue gas and air mixture spray into, on the one hand uncombusted in whirlwind melt-combustion room for guaranteeing Volatile matter and coal dust it is completely burned off, be on the other hand equivalent to flue gas recirculation, the generation of NOx can also be reduced.

It is further characterized by: using the combination of blade type turbulent burner and whirlwind combustion chamber, greatly increase The residence time of the mixability and coal dust of strong coal dust and air, meanwhile, high temperature air entrance is diagonally downward and adjustable angle (range be 10 ° ~ 80 °) reduces coal dust and has just enter into combustion chamber just from the ratio of high-temperature flue gas fairlead escape, while into one Step strengthens disturbance, burns more thorough.At the same time, in order to reduce the generation of NOx, First air and the high temperature for carrying coal dust are empty The excess air coefficient that gas Secondary Air is added together is maintained between 0.7-0.9, imperfect combustion to draw at branch in high temperature air The horizontal segment of outlet pipe mixes further after-flame with the air entered by horizontal tangential air port.

Small cyclones melt coal-powder boiler high temperature air and coal dust is mixed and burned, and form slag tap, can reduce in flue gas Fly ash content is good for the environment.

Detailed description of the invention:

Fig. 1 is the schematic diagram that a kind of small cyclones of the present invention melt coal-powder boiler;

Appended drawing reference: 1, blade type turbulent burner；2, swirl vane；3, whirlwind melts combustion chamber；4, left high temperature air Entrance；5, right high temperature air entrance；6, slag notch；7, high-temperature flue gas fairlead；8, the tangential air intake vent of first level flue；9, The tangential air intake vent of two horizontal flues；10, secondary furnace；11, exchange heat burner hearth

Specific embodiment:

Referring to Fig.1, for small cyclones melting coal-powder boiler mainly by blade type turbulent burner 1, whirlwind melt-combustion room 3 is high Warm flue gas fairlead 7, secondary furnace 10, heat exchange burner hearth 11 form.It is connected at the top of blade type turbulent burner 1 and melt-combustion room 3, 3 top middle position of combustion chamber is connected with high-temperature flue gas fairlead 7 simultaneously, and 3 bottom of combustion chamber is slag notch 6, and high-temperature flue gas draws Outlet pipe 7 enters secondary furnace 10 through one section of horizontal segment after the extraction of 3 top of combustion chamber, eventually enters into heat exchange burner hearth 11.Device operation When, First air carries coal dust and enters melt-combustion room 3 through blade type turbulent burner 1, meanwhile, high temperature air (Secondary Air) is by firing Two tangential high-temperature flue gas entries 4,5 for burning room upper end arrangement enter, and ignite coal dust, form high-temperature fusion burning.It is protected when operation The excess air factor of First air and high temperature air (Secondary Air) altogether is demonstrate,proved within the scope of 0.7-0.9, reduces the generation of NOx. Liquid lime-ash is flowed down along combustion chamber wall surface after burning, is discharged through slag notch 6, and the high-temperature flue gas for generation of burning is drawn by high-temperature flue gas Pipe 7 introduces secondary furnace 10, and the abundant afterburnt of combustible in flue gas is eventually entered into heat exchange burner hearth 10 in secondary furnace 10 and is changed Heat, therebetween, the tangential air intake vent 8,9 of 7 horizontal segment of high-temperature flue gas fairlead arrangement has appropriate flue gas and air mixture sprays into, So that in high-temperature flue gas due to the combustion chamber excess air coefficient combustible uncombusted less than 1 in secondary furnace 10 into one After-flame is walked, and finally fully enters heat exchange burner hearth 11 and exchanges heat.

Claims (4)

1. a small-scale cyclone melting pulverized coal furnace is characterized in that: It consists of a blade-type swirl burner (1), a vortex melting combustion chamber (3), a high-temperature flue gas extraction pipe (7), a burnout chamber (10) and a heat exchange furnace (11). A swirl vane (2) is installed in the burner (1) and is connected to the top of the swirl melting combustion chamber (3). 3); The upper part of the swirl melting combustion chamber (3) is cylindrical, and the lower part is conical. The upper left and right sides of the swirl melting combustion chamber (3) are arranged with tangentially inclined downward and adjustable high temperature air inlets ( 4, 5), the lower part of the vortex melting combustion chamber (3) is the slag outlet (6); the high temperature flue gas extraction pipe (7) is led out from the top center of the vortex melting combustion chamber (3), and two are arranged in the horizontal section. The tangential air inlets (8, 9), and the final horizontal end is connected to the burnout chamber (10) after a certain angle of expansion. The upper part of the burnout chamber (10) is the heat exchange furnace (11), and the heat exchange furnace (11) is arranged There is enough heat exchange surface to exchange heat with high temperature flue gas. 2. The small cyclone melting pulverized coal furnace according to claim 1, in order to enhance the mixing intensity and residence time of pulverized coal in the vortex melting combustion chamber (3), and at the same time reduce the escape of fuel from the high temperature flue gas extraction pipe (7) The amount of primary air and pulverized coal is fed by the blade type swirl burner (1). 3. The small cyclone pulverized coal furnace according to claim 1, the high temperature air enters from the tangentially inclined downward high temperature air inlets (4, 5) in the upper part of the vortex melting combustion chamber (3), and the pulverized coal and the high temperature air are sufficiently Mixed combustion, the combustion temperature is higher than the melting point of coal ash, the strong vortex and high temperature greatly reduce the fly ash content, the molten ash flows down the wall of the combustion chamber, and enters the water-cooled slag hopper from the lower slag outlet (6). 4. The small cyclone pulverized coal melting furnace according to claim 1, the total air excess coefficient entering the combustion chamber from the blade-type swirl burner (1) and the tangential high temperature air inlets (4, 5) is between 0.7 and 0.9 At the same time, the two tangential air inlets (8, 9) in the horizontal section of the high-temperature flue gas outlet pipe are fed with a mixture of flue gas and air, and according to the actual operation Under the working conditions, the incoming flue gas and air are adjusted between 0-0.5 of the smoke-to-air ratio.