CN201636837U

CN201636837U - Mid-board water cooled wall of hearth of circulating fluidized bed boiler

Info

Publication number: CN201636837U
Application number: CN2010201478959U
Authority: CN
Inventors: 聂立; 苏虎; 杨虎; 黄敏; 巩李明; 杨雪芬
Original assignee: Dongfang Boiler Group Co Ltd
Current assignee: Dongfang Boiler Group Co Ltd
Priority date: 2010-03-31
Filing date: 2010-03-31
Publication date: 2010-11-17
Anticipated expiration: 2020-03-31

Abstract

The utility model discloses a mid-board water cooled wall of a hearth of a circulating fluidized bed boiler, comprising a separated hearth at the bottom, wherein the water cooled wall inside the lower hearth converges at the lower end of a mid-board. The mid-board water cooled wall is characterized in that an upward single-layer tube is led out to form a tube panel of the mid-board water cooled wall after the water cooled wall inside the lower hearth converges at the lower end of the mid-board, and flue gas and material balance channels are formed on both sides of the separated hearth through a bending tube in the mid-board water-cooled wall. The utility model has the advantages that the single-layer water cooled wall is easy to process and the mid-board water cooled wall is exposed on both sides of the hearth, thereby increasing the effective evaporation heating area of the hearth greatly and saving the cost.

Description

The mid-board water-cooling wall of boiler hearth of circulating fluidized bed

Technical field

The utility model relates to a kind of mid-board structure and burner hearth pattern that is used in recirculating fluidized bed (CFB) furnace of power-plant boilers.

Background technology

Recirculating fluidized bed (CFB) combustion technology is that to have a fuel tolerance good, efficient height, the clean combustion technology of advantage such as pollutant emission is few.In recent years, CFB boiler technology development both at home and abroad was very fast, and the domestic Large-scale CFB boiler that has put into operation is the subcritical parameter grade of 300MW, and the CFB boiler of supercritical parameter also puts into operation in the world.

Along with the increasing of boiler capacity grade, the corresponding increase in boiler furnace cross section.Because be subjected to the restriction of lower furnace portion secondary wind penetration depth, for reaching burner hearth breadth depth ratio preferably, the design of bottom split burner hearth is good solution.But existing bottom split burner hearth, in forming the pipe of side wall need two-in-one after water-cooling wall around the wraparound burner hearth again, complex structure, to make installation workload big, and may become the multiple point of fault.

Simultaneously, because after the boiler capacity increase, the evaporating heating surface that is arranged in the burner hearth also needs corresponding increase.The mode that prior art increases evaporating heating surface has two kinds.The one, by realizing with additional heat-transfer surface.For example curtain wall, expansion water-cooling wall, external heat exchanger etc., but problems such as disturbance that causes by concurrent flow in service in short-term that brings thus and complex system.The 2nd, realize by increasing furnace height.But it is long-pending that too high burner hearth has only increased the theoretical surface of burner hearth evaporating heating surface.And because CFB boiler furnace top is that particle concentration is lower, i.e. the lower zone of the coefficient of heat transfer, the effectively increase of evaporation heating area and not obvious.The utilization rate of heating surface reduces.

In order to address this problem, a kind of band boiler hearth of circulating fluidized bed of water-cooling wall mid-board is back-to-back disclosed in Chinese utility model patent 200620035303.8, comprise and contain inboard wearing layer, before the burner hearth of water-cooling wall and outside heat-insulation layer, after, a left side, right body of wall and burner hearth top, on each body of wall water-cooling wall, next part case and burner hearth top water-cooling wall collection case, before being located at, slag-drip opening on the back wall, the feed back import, the lime stone import, fuel inlet and secondary wind inlet and exhanst gas outlet, be positioned at lower furnace portion and comprise air distribution plate, blast cap is before interior, back siege and be located at its bottom before, back air compartment is before being positioned at, the wearing layer that contains that is down the setting of " V " type between the back siege, before the siege dividing wall of water-cooling wall and heat-insulation layer and the lower end thereof, back next part case; Between siege dividing wall top and burner hearth top, also be provided with a formula water-cooling wall mid-board and a upper and lower collection case thereof back-to-back, its upper collecting chamber both sides are communicated with the next part case and then are communicated with siege dividing wall two side walls with the roof of the furnace water-cooling wall, the upper and lower collection case of mid-board two ends all are fastenedly connected with both sides burner hearth body of wall.This utility model has been simplified lower furnace portion and water wall structure thereof, increases furnace heating surface long-pending 10～20%.Yet this utility model adopts back-to-back that the mid-board of water-cooling wall form can cause following problem: if adopt hermetically-sealed construction back-to-back between the water-cooling wall, inner air when being heated because the thermal coefficient of expansion difference, the capacity fracture; If do not adopt hermetically-sealed construction back-to-back between the water-cooling wall, then dust stratification easily in the slit between two water-cooling walls influences heat exchange.

The utility model content

The purpose of this utility model is to propose mid-board water wall structure in a kind of stove simple and reliable for structure.By enforcement of the present utility model, when simplifying the lower furnace structure, effectively increased the heating surface area of furnace wall cooling, improved water circulation reliability, and can solve the carrying problem of burner hearth air distribution plate load, and significantly reduced manufacturing and installation workload, reduced the possibility that breaks down.

The technical solution of the utility model is as follows: a kind of mid-board water-cooling wall of boiler hearth of circulating fluidized bed, have the bottom and be the burner hearth of split type burner hearth, side wall compiles in the mid-board lower end in the lower furnace, it is characterized in that: side wall is drawn upwards individual layer pipe composition mid-board panelized-tube-wall section in the lower furnace after the mid-board lower end is compiled, and forms split burner hearth both sides flue gas, material balance passage by crooked pipe in the mid-board water-cooling wall.

Supplementary technology scheme of the present utility model is as follows: preferably, in the lower furnace side wall in the mid-board lower end by a kind of the compiling in three-way pipe or collection case or the crooked pipe.

Preferably, the angle of cut of side wall and mid-board center line is 15～60 ℃ in the formation split burner hearth.

The beneficial effects of the utility model are: individual layer water-cooling wall processing technology is simple, and mid-board water-cooling wall double-sided exposure in burner hearth can be saved cost when rolling up the effective evaporation heating area of burner hearth.

Description of drawings

The utility model will illustrate that wherein: Fig. 1 is the structural representation of specific embodiment of the utility model by example and with reference to the mode of accompanying drawing.

Fig. 2 is that the A of Fig. 1 is to view.

Fig. 3 is the cutaway view of three-way pipe.

Fig. 4 is the cutaway view of next part case.

The specific embodiment

Specific embodiment of the utility model, as shown in Figure 1, a kind of mid-board water-cooling wall of boiler hearth of circulating fluidized bed, mid-board water-cooling wall 10 is the individual layer panelized-tube-wall section, and double-sided exposure is installed in the burner hearth 1, with mid-board water-cooling wall 10 lower ends is hinge, and side wall in the lower furnace 9 by mid-board lower end three-way pipe or collection case 8 or crooked pipe transition, is drawn upwards pipe composition mid-board panelized-tube-wall section by transition.As shown in Figure 2, form split burner hearth both sides flue gas, material balance passage by crooked pipe simultaneously,, keep the bed of both sides to flatten weighing apparatus with freely exchanging of flue gas and particle in the burner hearth of assurance mid-board both sides.The split burner hearth inside wall that forms in the present embodiment and the angle of cut of mid-board center line are 15～60 ℃.

With respect to former split furnace water cooling wall construction, adopt the utility model rear hearth water wall structure to obtain very big simplification: 1. the interior side wall 9 of drawing from next part case 5,6 in the burner hearth 1 is up, form bottom split inboard wall of burner hearth, mid-board water-cooling wall 10, come together in upper collecting chamber 7 at last; 2. burner hearth 1 outer side wall is up, forms the outer side wall of air compartment water-cooling wall, air distribution plate and burner hearth, comes together in upper collecting chamber at last.On the outer wall of burner hearth 1, be provided with overfiren air port 2, fuel port 3, be furnished with desulfurizing agent 4 on the air distribution plate, adopt the inside and outside side water wall tube of present embodiment structure to arrange clear succinct.

The utility model is not limited to the aforesaid specific embodiment.The utility model expands to any new feature or any new combination that discloses in this manual, and the arbitrary new method that discloses or step or any new combination of process.

Claims

1. the mid-board water-cooling wall of a boiler hearth of circulating fluidized bed, have the bottom and be the burner hearth of split type burner hearth, side wall compiles in the mid-board lower end in the lower furnace, it is characterized in that: side wall is drawn upwards individual layer pipe composition mid-board panelized-tube-wall section in the lower furnace after the mid-board lower end is compiled, and forms split burner hearth both sides flue gas, material balance passage by crooked pipe in the mid-board water-cooling wall.

2. the mid-board water-cooling wall of boiler hearth of circulating fluidized bed according to claim 1 is characterized in that: in the lower furnace side wall in the mid-board lower end by a kind of the compiling in three-way pipe or collection case or the crooked pipe.

3. the mid-board water-cooling wall of boiler hearth of circulating fluidized bed according to claim 1 and 2 is characterized in that: form that the angle of cut of side wall and mid-board center line is 15～60 ℃ in the split burner hearth.