CN202792004U

CN202792004U - Material returning device of circulating fluidized bed boiler

Info

Publication number: CN202792004U
Application number: CN201220426379.9U
Authority: CN
Inventors: 俞伟伟; 黄建荣; 许秀启; 黄永志; 姜雯雯; 肖锋; 吕俊复
Original assignee: Tsinghua University; Shanghai Boiler Works Co Ltd
Current assignee: Tsinghua University; Shanghai Boiler Works Co Ltd
Priority date: 2012-08-24
Filing date: 2012-08-24
Publication date: 2013-03-13
Anticipated expiration: 2022-08-24

Abstract

A material returning device of a circulating fluidized bed boiler belongs to the technical field of circulating fluidized bed boiler equipment, and comprises a vertical feed leg, a movable filling bed, a material returning bed and a material returning tube, wherein the movable filling bed is aslant arranged, and forms an included angle of 30-60 degrees in the vertical direction; the movable filling bed, the material returning bed and the material returning tube form an inverted N-shaped structure; and air distribution bellows are arranged on the inclined plane of the movable filling bed and on the bottom surface of the material returning bed. The working principle of the material returning device is that materials separated by a separator are sent back to a furnace chamber by using the movable filling bed and the fluidifying air of the material returning bed; and the material returning device has the characteristic that the problem of larger flow resistance in a horizontal channel of the conventional U-shaped valve is efficiently solved by using the aslant arranged movable filling bed which utilizes the material gravity effect.

Description

A kind of material lifting device of circulation fluidized boiler

Technical field

The utility model relates to a kind of feeding back device of CFBB, belongs to the Circulating Fluidized Bed Boiler Equipment technical field.

Background technology

Solid material circulation foldback burner hearth is the key character of CFBB, and material circulating system is the important component part of CFBB.The Matter Transfer loop mainly is made of raising section, separator and feeding back device, and the service behaviour of feeding back device directly has influence on the safe and stable operation of CFBB.Feeding back device mainly plays two aspects.The solid particle that on the one hand separator is separated is returned the burner hearth of higher pressure by the separator foldback of low pressure, realize reciprocation cycle burning and the reaction of boiler oil and lime stone; On the other hand, in the material returning valve dipleg, form material envelope by recycle stock, prevent from that malleation flue gas anti-channeling in the stove from entering in the separator of negative pressure to cause the flue gas short circuit, destroy normal combustion and heat transfer in normal Gas-solid Two-phase Flow in the separator and the stove.

The present domestic and international large-size circulating fluidized bed U-shaped material returning valve that generally adopts.The U valve loop seal that is otherwise known as, practical operation situation show, U-shaped valve arrangement is simple, reliable, can satisfy well the requirement of stablizing returning charge and sealing, is fit to the layout of CFBB.Fig. 1 is the structure principle chart of typical U-shaped valve, mainly is made of with being connected with the horizontal channel descending standpipe moving bed, up bubbling returning charge bed.During actual motion, the returning charge blast that moving bed and returning charge bed bed provide is mainly used in overcoming following resistance: 1) material returning valve air distribution plate resistance; 2) down-comer stock column pressure; 3) horizontal channel resistance in the valve; 4) tedge material resistance; 5) the returning charge inclined tube advances burner hearth porch furnace pressure.

Along with the CFBB capacity constantly increases, the circular flow of material constantly increases.Under higher operating load, the flow resistance of returning charge valve horizontal channel obviously raises, and causes the returning charge fan pressure not and can't returning charge.For overcoming the problem of returning charge fan pressure head deficiency, a kind of more common way is to arrange from top to bottom that in the moving bed lower end three to five the tunnel laterally become flexible wind to reduce total flow resistance, as shown in Figure 2.But this way increases equipment cost and operation control difficulty so that the returning charge wind system is complicated, is unfavorable for the large-scale promotion use.

The utility model content

The purpose of this utility model provides a kind of material lifting device of circulation fluidized boiler, to solve the U-shaped valve of above-mentioned tradition resistance excessive problem in horizontal channel under high circular flow.

The technical solution of the utility model is as follows:

A kind of material lifting device of circulation fluidized boiler comprises vertical dipleg, moving packed bed, returning charge bed and refeed line, it is characterized in that: described moving packed bed is and is in tilted layout, and is 30 °～60 ° angles with vertical direction; Described moving packed bed, returning charge bed and refeed line form " shape of falling N " structure; Be furnished with the moving packed bed bellows in the moving packed bed bottom, be furnished with returning charge bed bellows in returning charge bed bottom.

The airflow direction of moving packed bed bellows described in the utility model and vertical direction are 60 °～120 ° angles.

The utlity model has following outstanding advantages and effect: 1. adopt the tilting moving packed bed, effectively utilized the Action of Gravity Field of material, greatly reduced traditional U-shaped valve horizontal channel flow resistance, made material returning valve under high load capacity and large feed back amount, can stablize feed back; 2. the U-shaped valve with respect to the laterally loosening wind of band has reduced cloth wind bellows number, reduces equipment investment, reduces operation control complexity, is conducive to large-scale promotion and application.

Description of drawings

Fig. 1 is the structural representation of existing U-shaped material returning valve.

Fig. 2 is a kind of improved U-shaped valve arrangement schematic diagram with the loosening wind of level.

" fall N-type " material returning valve structural representation of a kind of low flow resistance that Fig. 3 provides for the utility model.

Fig. 4 is inclination moving packed bed inclination angle of inclined plane schematic diagram.

Fig. 5 is moving packed bed airflow direction schematic diagram.

The vertical standpipe of mark among the figure: 1-; The 2-moving packed bed; 3-returning charge bed; The 4-refeed line; 5-moving packed bed bellows; 6-returning charge bed bellows; The 7-horizontal channel; The 8-level is become flexible the wind bellows.

The specific embodiment

Further specify principle of the present utility model, structure and embodiment below in conjunction with accompanying drawing.

As shown in Figure 3, a kind of material lifting device of circulation fluidized boiler that the utility model provides comprises vertical dipleg 1, moving packed bed 2, returning charge bed 3 and refeed line 4; Described moving packed bed is and is in tilted layout, and with the angle α of vertical direction be 30 °～60 ° (as shown in Figure 4); Described moving packed bed 2, returning charge bed 3 and refeed line 4 form " shape of falling N " structure; Be furnished with moving packed bed bellows 5 in moving packed bed 2 bottoms, be furnished with returning charge bed bellows 6 in returning charge bed bottom.

The airflow direction of the moving packed bed bellows 6 of moving packed bed 2 lower disposed described in the utility model and the angle β of vertical direction are 60 °～120 ° (as shown in Figure 5).

As shown in Figure 3, vertically dipleg 1 links to each other with the cyclone separator of CFBB, vertically be connected to inclination moving packed bed 2 behind the dipleg 1, under the acting in conjunction of fluidized wind and bed material gravity, material is transported to the returning charge bed 3 that is connected to behind the moving packed bed, the wind action of returning charge bed fluidisation leave the bed the material be transported to refeed line 4, return burner hearth by refeed line.Fluidisation air quantity by reasonable disposition inclination moving packed bed 2 and returning charge bed 3 is so that material flow resistance in material returning valve is less, and then under identical conveying capacity and furnace pressure, reduce the outlet blast of roots blower, reduction equipment operating cost and control difficulty realize the stability and safety returning charge.

With respect to traditional U-shaped valve material returning device shown in Figure 1 and a kind of improved U-shaped valve material returning device with the loosening wind of level shown in Figure 2, the utility model utilizes the structural design of the tilting moving packed bed of material gravity effect effectively to overcome the large problem of traditional U-shaped valve horizontal channel flow resistance under the precondition that does not increase cloth wind bellows number.

Claims

1. material lifting device of circulation fluidized boiler, comprise vertical dipleg (1), moving packed bed (2), returning charge bed (3) and refeed line (4), it is characterized in that: described moving packed bed (2) is and is in tilted layout, and with 30 °～60 ° angles of vertical direction; Described moving packed bed (2), returning charge bed (3) and refeed line (4) form " shape of falling N " structure; Be furnished with moving packed bed bellows (5) in the moving packed bed bottom, be furnished with returning charge bed bellows (6) in returning charge bed bottom.

2. material lifting device of circulation fluidized boiler according to claim 1 is characterized in that: 60 °～120 ° angles of the airflow direction of described moving packed bed bellows (5) and vertical direction.