CN203431841U - Small-capacity circulating fluidized bed boiler - Google Patents

Abstract

The utility model discloses a small-capacity circulating fluidized bed boiler. A circulating combustion system comprises a fluidized bed, a hearth, a cyclone separator and return feeders; a water cooling system comprises upper and lower drums, a convection bank, membrane-type water cooling walls and a header; the periphery of the hearth and the top of the boiler are provided with the membrane-type water cooling walls; the convection bank between the upper and lower drums is internally provided with smoke baffle plates; smoke of the circulating combustion system flows to the fluidized bed, the hearth, the cyclone separator, the convection bank, a coal economizer and a smoke outlet sequentially. The small-capacity circulating fluidized bed boiler is used for combusting fault coal with low calorific value, thereby being remarkable in efficiency and high in thermal efficiency.

Description

A kind of low capacity CFBB

Technical field

The utility model relates to a kind of boiler, especially relates to a kind of low capacity CFBB, in order to lower heat of combustion colm.

Background technology

China's low capacity boiler is main mainly with grate firing boiler greatly, and this boiler series coal adaptability is poor, and boiler efficiency is on the low side.And the area of coal in China reserves distributes very inhomogeneous, a large amount of fat coals concentrates on North China, northwest and middle and south region-by-region, and south and the coastal area reserves of industry prosperity are relatively limited, be mostly colm, if can fully utilize the abundant colm of these reserves, not only can adjust the energy resource structure of China, also for gathering materials on the spot of part power-equipment provides good development space, therefore applying soft coal is important energy policy of China, at present the domestic fluidized-bed combustion boiler that there is no lower heat of combustion colm.

Summary of the invention

The purpose of this utility model is: a kind of lower heat of combustion colm, usefulness is remarkable, the thermal efficiency is high low capacity CFBB are provided.

The technical solution of the utility model is: comprise circulating combustion system, water-cooling system, economizer, circulating combustion system comprises fluid bed, burner hearth, cyclone separator and material returning device, water-cooling system comprises lower drum, convection bank, fin panel casing and header, between upper lower drum, be furnished with convection bank, burner hearth surrounding and furnace roof have fin panel casing, water-cooling wall connects header, cyclone separator is set after fluid bed and burner hearth, lower drum and convection bank are set after cyclone separator, economizer is set after upper lower drum and convection bank, in convection bank between upper lower drum, smoke bending plate is set, the flue gas flow direction of circulating combustion system is as fluid bed, burner hearth, cyclone separator, convection bank, economizer, outlet flue.

Further, in the convection bank between upper lower drum, twice smoke bending plate is set.

The beneficial effects of the utility model are: 1, usefulness is remarkable, the thermal efficiency is high, and burning of coal efficiency can reach 96～99%, and ash content carbon is only 2% left and right, and boiler thermal output can reach 85% left and right, than relevant national standard, improve 15 to 20 percentage points.2, coal adaptability is wide, calorific value all can be stablized in same boiler at bituminous coal, meager coal, anthracite, the brown coal of 3000～7000kcal/kg, efficient burning, and can mix burned coal gangue, gas-making cinder and grate furnace slag, both be three height (ash-rich, high moisture content, high-sulfur) three low (low-volatile, low heating value, low ash smelting point) fuel, also efficient burning therein.3, Load Regulation is good, can be in 25%～110% load range free adjustment, high underload no matter, its efficiency of combustion all can keep higher value; Load Regulation speed, average per minutely reaches 5%.4, clean burning, protection of the environment, ignition temperature is only 850 ℃～950 ℃ left and right, belong to low-temperature burning, adopt fractional combustion, air is along combustion flow to sending into from differing heights simultaneously, and combustion chamber is in reducing atmosphere, thereby this technology has three large benefits aspect environmental protection: admixture lime stone in fuel, can economic desulfurization, Ca/S mol ratio is 1.5～2 o'clock, desulfuration efficiency can reach 84% left and right; The discharge capacity of NOX can be controlled in below 200ppm; Slag activity is good, and phosphorus content is low, can make clinker and construction material.5, igniting is convenient, the banking fire time is long, and volume heat load is higher, and its emulsion zone sectional area is only 1/3～1/2 of conventional flow fluidized bed boiler, and emulsion zone is thermal-insulating chamber simultaneously, therefore light a fire convenient and swift, and the longest reaching about 20 hours of banking fire time.6, compact conformation, maintenance capacity are few, due to mechanical transmissioning piece seldom, simultaneously without pipe laying heating surface, can fundamentally eliminate fault and the buried pipe abrasion of fire grate transmission, extend the cycle of operation, reduced labor strength.

Accompanying drawing explanation

Fig. 1 is structural representation of the present utility model.

Figure labeling description: 1, slag dropping tube, 2, airducts, 3, blast cap, 4, coal conveyor, 5, fluid bed, 6, burner hearth, 7, water-cooling wall, 8, separator, 9, convection bank, 10, smoke bending plate, 11, drum, 12, economizer, 13, header, 14, outlet flue, 15, ash port, 16, material returning device.

The specific embodiment

From structural representation of the present utility model shown in Fig. 1, can find out, the utility model comprises circulating combustion system, water-cooling system, economizer 12, and overall structure is rebuilding, and lower floor is mainly slags tap, puts ash and blowdown, the operation running layer that upper strata is boiler.Circulating combustion system comprises fluid bed 5, burner hearth 6, high temperature cyclone separator 8 and material returning device 16, the fluid bed 5 that bottom is comprised of wear-resistant castable and grid plate hood 3, the burner hearth 6 that top is comprised of the fin panel casing 7 of parallel baffled.Water-cooling system comprises lower drum 11, convection bank 9, water-cooling wall 7 and header 13, boiler body adopts double-barrel transverse formula Natural Circulation, between upper lower drum 11, be furnished with convection bank 9, burner hearth 6 surroundings and furnace roof have fin panel casing 7, water-cooling wall 7 connects header 13, cyclone separator 8 is set after fluid bed 5 and burner hearth 6, lower drum 11 and convection bank 9 are set after cyclone separator 8, economizer 12 is set after upper lower drum 11 and convection bank 9, the interior twice smoke bending plate 10 that arranges of convection bank 9 between upper lower drum, making flue gas is that three backhauls mixing are washed away.Economizer 12 is steel tube economizer, and minute upper and lower two stage arrangement is the coiled pipe composition that boiler tube bends, and feedwater, becomes reverse flow with flue gas along coiled pipe from bottom to top.Air preheater adopts flue gas and air to intersect flow direction structure, by electrically welded tube and steel plate installed-welded, is formed, and inner tube smoke is made parallel baffled, manages outer air and makes transversal flow, and primary and secondary air preheat temperature reaches respectively 8O ℃.The interior top of burner hearth 6 fin panel casing is light pipe, and the internal layer of the fin panel casing of below adopts fire-resistant abrasion-proof castable, and the skin of fin panel casing adopts alumina silicate fiber felt to variegate guard board structure.Cyclone separator 8 and material returning device 16 adopt recirculating fluidized bed antiwear refractory brick and abrasion-proof and refractory pouring material, 6 millimeters of steel plate building enclosures of peripheral employing.For convenience of operation, the inspection and maintenance of boiler, inspection door is all arranged in fluid bed 5, cyclone separator 8 tops and back-end surfaces top and the bottom, and two material returning devices 16 are provided with shoot door.

The flue gas flow direction of circulating combustion system of the present utility model is as fluid bed 5, burner hearth 6, burner hearth exhanst gas outlet, cyclone separator 8, cyclone separator outlet, convection bank 9, to stream interface exhanst gas outlet, economizer 12, outlet flue 14.Its operation principle is: coal is sent into fluid bed 5 through being located at spiral coal conveyor 4 high positions for stokehold, the required air that burns is divided into a wind (accounting for 50～60%), Secondary Air (accounting for 50～40%), one time wind is sent into fluid bed 5 bottom bellows by an airduct 2, through air distribution plate and heat resisting cast steel blast cap 3, enter fluid bed, fuel is blown afloat and fluidized bed combustion; Secondary Air is sent into fluid bed 5 top secondary air box by post-blast machine through air preheater, by upper and lower two-layer jet pipe, inject fluid bed 5, fluid bed 5 fluidizing velocities are controlled at 5.5～6.5m/s, burner hearth 6 top fluidizing velocities are controlled at 4～4.5m/s, in burner hearth 6 top partial material, with high-temperature flue gas, with the speed of 23-25 m/s, tangentially enter high temperature cyclone separator 8, carry out gas solid separation; High-temperature flue gas enters the convection heating surface that convection bank 9 forms, and through twice smoke bending plate 10, washes away, and enters economizer 12, then discharges from outlet flue 14, from ash port 15 ash discharges.For preventing the wearing and tearing of high speed flue gas to fin panel casing 7 heating surfaces, the pipe between two smokestacks of rear fin panel casing is all drawn in flue layer.The resistance of cyclone separator 8 is below 1200Pa, and the separated material that do not burn getting off is again sent into fluid bed 5 by two material returning devices 16 and repeatedly burnt, from slag dropping tube 1 slag that falls.

Claims (2)

1. a low capacity CFBB, comprises circulating combustion system, water-cooling system, economizer (12), is characterized in that: described circulating combustion system comprises fluid bed (5), burner hearth (6), cyclone separator (8) and material returning device (16), water-cooling system comprises lower drum (11), convection bank (9), fin panel casing (7) and header (13), between upper lower drum (11), be furnished with convection bank (9), burner hearth (6) surrounding and furnace roof have fin panel casing (7), water-cooling wall (7) connects header (13), cyclone separator (8) is set after fluid bed (5) and burner hearth (6), lower drum (11) and convection bank (9) are set after cyclone separator (8), economizer (12) is set after upper lower drum (11) and convection bank (9), in convection bank (9) between upper lower drum (11), smoke bending plate (10) is set, the flue gas flow direction of described circulating combustion system is as fluid bed (5), burner hearth (6), cyclone separator (8), convection bank (9), economizer (12), outlet flue (14).

2. low capacity CFBB according to claim 1, is characterized in that: in the convection bank (9) between described upper lower drum (11), twice smoke bending plate (10) is set.

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