CN211853982U - Low-nitrogen environment-friendly circulating fluidized bed hot water boiler - Google Patents

Abstract

The utility model belongs to the field of boiler equipment, in particular to a low-nitrogen environment-friendly circulating fluidized bed hot water boiler, which can improve the separation efficiency and reduce the energy consumption and NOx emission, and comprises a hearth, a separator and a tail flue, wherein the bottom of the separator is provided with a material returning device communicated with the hearth, the hearth is provided with a coal feeding device, the bottom of the hearth is provided with an air distribution plate and an ignition device, the tail flue is internally provided with a coal economizer and an air preheater, the side part of the ignition device is provided with a primary hot air inlet, the front end of the ignition device is provided with an expanding area and a buffer area, the buffer area covers the whole air chamber below the air distribution plate, the separator comprises two separators, the central cylinder of each separator is eccentrically arranged, the volute of the separator is declined downwards, the inlet flue of the separator is arranged by narrowing along the air inlet direction, the coal economizer consists of at least two rows of economizer pipes, the two adjacent, the coal economizer pipes in the same row are arranged in line.

Description

Low-nitrogen environment-friendly circulating fluidized bed hot water boiler

Technical Field

The utility model belongs to the boiler equipment field, concretely relates to low nitrogen environmental protection circulating fluidized bed boiler.

Background

With the stricter national environmental protection policy, the prior circulating fluidized bed hot water boiler technology cannot meet the environmental protection requirement. The prior art has the defects of low separation efficiency of a separator, high bed temperature, high NOx emission, high coal consumption and the like, and can not meet the requirements of the existing enterprises.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem that current circulating fluidized bed boiler separation efficiency is low, the energy consumption is high, NOx discharges high, the utility model provides a low nitrogen environmental protection circulating fluidized bed boiler, it can improve separation efficiency, reduces energy consumption and NOx and discharges.

The technical scheme is as follows: a low-nitrogen environment-friendly circulating fluidized bed hot water boiler comprises a hearth, separators and a tail flue, wherein a material returning device communicated with the hearth is arranged at the bottom of each separator, a coal feeding device is arranged on the hearth, an air distribution plate and an ignition device are arranged at the bottom of the hearth, and an economizer and an air preheater are arranged in the tail flue, and the boiler is characterized in that a primary hot air inlet is formed in the side part of each ignition device, a flaring area and a buffer area are arranged at the front end of each ignition device, the buffer area covers the whole air chamber below the air distribution plate, the separators comprise two separators, the central cylinders of the separators are eccentrically arranged, spiral cases of the separators are downwards inclined, the inlet flues of the separators are arranged by narrowing along the air inlet direction, each economizer comprises at least two rows of economizer pipes, and the two adjacent rows of economizer pipes are staggered, the economizer pipes in the same row are arranged in series.

The coal economizer is further characterized in that the hearth is of a membrane type water-cooled wall structure, and all areas where the coal economizer is located are guard plate furnace walls;

the material returning device is provided with three air chambers which are respectively connected with loosening air, air conveying and returning air;

the air preheater is horizontally arranged, and the proportion of primary air to secondary air is 1: 1;

the final stage of the air preheater adopts an enamel pipe;

and a water-cooling screen is arranged in the hearth.

Adopt the utility model discloses afterwards, the separator sets up two, and the separator spiral case has a down dip, improve separator import flue department import speed, the separation efficiency that the separator was improved to designs such as center section of thick bamboo eccentric arrangement, the economizer adopts in-line and staggered combination to arrange, be difficult for the deposition, improve heat transfer effect, practice thrift the energy consumption greatly, and ignition department adopts the flaring district to add the buffer zone structure, wind is through the flaring district, the buffer zone of flowing through, last steady even entering plenum, the no blind spot of air distribution plate has been guaranteed, no eccentric district, no local rich oxygen district, effectively reduced NOx's formation.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the ignition device;

FIG. 3 is a front view of the separator;

FIG. 4 is a top view of the separator;

FIG. 5 is a schematic view of an economizer;

fig. 6 is a layout view of an economizer pipe.

Detailed Description

The boiler comprises a hearth 1, a separator 2 and a tail flue 6, wherein a material returning device 4 communicated with the hearth 1 is arranged at the bottom of the separator 2, three air chambers are arranged in the material returning device 4, loosening air, conveying air and returning air are respectively connected into the air chambers, the loosening air, the conveying air and the returning air are sequentially loosened, the conveying air and the returning air are conveyed and returned, a material returning hood and a connecting pipe in the material returning device are welded, and the phenomenon that a hood head falls off in the operation process and a coal feeding device is arranged on the hearth with unsmooth material returning is avoided. The bottom of the hearth 1 is provided with an air distribution plate 7 and an ignition device 8, a tail flue 6 is internally provided with a coal economizer 4 and an air preheater 5, the side part of the ignition device 8 is provided with a primary hot air inlet 11, the front end of the ignition device 8 is provided with an expanding area 12 and a buffer area 13, the buffer area covers the whole air chamber below the air distribution plate, the separators 2 comprise two separators which are arranged left and right, the diameters of the separators 2 are as large as possible, the central cylinder 14 of each separator 2 is eccentrically arranged, the volute 15 of each separator 2 is declined, the inlet flues of the separators 2 are arranged along the air inlet direction from wide to narrow, the flue gas inlet speed is improved, each coal economizer comprises three rows of coal economizer pipes 16, two adjacent rows of coal economizer pipes 16 are arranged in a staggered manner, the same row of coal economizer pipes 16 are arranged in a sequential manner, the single coal economizer pipes 16 arranged in a sequential manner are easy to. And the single coal economizer pipe 16 which is arranged in a staggered way cannot meet the requirement of the flow velocity of working media in the pipe. In order to reduce the steel consumption of the coal economizer and improve the heat transfer coefficient of a heating surface, the currently designed coal economizer is arranged in a staggered manner on the basis of arranging three pipe rings in a row. Taking a 168MW hot water boiler as an example, the specification of the pipe is phi 42 x 3.5, and under the condition that the working medium speed and the flue gas speed are reasonable, the area of the coal economizer can be reduced by about 1000 square meters. The upper-level economizer is suspended on the top plate through a water hanging pipe, and the lower-level economizer is suspended through a pipe clamp. A denitration space is reserved between the two-stage coal economizer 4.

The hearth 1 is of a membrane type water-cooled wall structure, and the areas where the economizers 4 are located are all guard plate furnace walls; a water-cooling screen 11 is arranged in the hearth 1, low-temperature backwater passes through a backwater distribution header, one path of backwater is introduced into a water-cooling screen inlet header, and the backwater goes upwards along the water-cooling screen to enter a water-cooling screen upper header and then enters the boiler barrel. Taking 168MW boiler as an example, the design of water-cooling screen can make furnace height and the whole height reduction of boiler 6 meters, and greatly reduced boiler steel consumption improves boiler market competition.

The air preheater is horizontally arranged, and the proportion of primary air to secondary air is 1: 1; the final stage of the air preheater adopts an enamel pipe in order to prevent low-temperature corrosion and ash blockage.

Claims (6)

1. A low-nitrogen environment-friendly circulating fluidized bed hot water boiler comprises a hearth, separators and a tail flue, wherein a material returning device communicated with the hearth is arranged at the bottom of each separator, a coal feeding device is arranged on the hearth, an air distribution plate and an ignition device are arranged at the bottom of the hearth, and an economizer and an air preheater are arranged in the tail flue, and the boiler is characterized in that a primary hot air inlet is formed in the side part of each ignition device, a flaring area and a buffer area are arranged at the front end of each ignition device, the buffer area covers the whole air chamber below the air distribution plate, the separators comprise two separators, the central cylinders of the separators are eccentrically arranged, spiral cases of the separators are downwards inclined, the inlet flues of the separators are arranged by narrowing along the air inlet direction, each economizer comprises at least two rows of economizer pipes, and the two adjacent rows of economizer pipes are staggered, the economizer pipes in the same row are arranged in series.

2. The low-nitrogen environment-friendly circulating fluidized bed hot water boiler according to claim 1, wherein the furnace is of a membrane wall structure, and the areas where the economizers are located are all furnace walls with guard plates.

3. The hot water boiler according to claim 1, wherein the return means is provided with three air chambers to which the loosening air, the supply air and the return air are supplied.

4. The low-nitrogen environment-friendly circulating fluidized bed hot water boiler according to claim 1, wherein the air preheater is horizontally arranged and has a primary air ratio and a secondary air ratio of 1: 1.

5. the low-nitrogen environment-friendly circulating fluidized bed hot water boiler according to claim 1, wherein an enamel pipe is used as a final stage of the air preheater.

6. The low-nitrogen environment-friendly circulating fluidized bed hot water boiler according to claim 1, wherein a water screen is provided in the furnace chamber.

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