WO2013020360A1

WO2013020360A1 - Differential-velocity multi-cyclone conical-bed air distribution structure

Info

Publication number: WO2013020360A1
Application number: PCT/CN2012/001045
Authority: WO
Inventors: 杨文�; 周圣林; 徐勇敏; 边际
Original assignee: 江西江联能源环保股份有限公司
Priority date: 2011-08-05
Filing date: 2012-08-03
Publication date: 2013-02-14
Also published as: CN102353045B; CN102353045A

Abstract

A differential-velocity multi-cyclone conical-bed air distribution structure. Ladder-type bed surfaces are arranged at a high position and a low position in a boiler furnace (12). A high-speed bed (1) is arranged at the low position. A low-speed bed (2) is arranged at the high position. The high-speed bed (1) adopts a structure of V-shaped air distribution plates (10) and a plurality of conical air distribution chambers (8). A large-aperture V-shaped slag removal device (3) is arranged at the bottoms of the two V-shaped air distribution plates (10) and between every adjacent two of the conical air distribution chambers (8). Immersion heating surface pipes (5) and immersion superheaters (6) are arranged on the low-speed bed (2). The V-shaped air distribution plates (10) are provided with several T-shaped blast caps (9). A low-speed air chamber (4) is arranged below the low-speed bed (2). Upper ends of side walls of the boiler furnace (12) are respectively provided with negative pressure feeders (11) and multi-layer cyclone three-stage air supply outlets (7). The boiler solves the problems that because of combustion of biomass or garbage, ash is gathered in a superheater; a superheater is corroded; and slag in a superheater is removed smoothly, so as to improve combustion efficiency and reduce wear.

Description

High-efficiency differential multi-swirl cone bed air structure for burning biomass or garbage fuel boiler

Technical field

The present invention relates to a boiler, and more particularly to a high efficiency differential multi-swirl conical bed air distribution structure for a biomass or waste fuel boiler.

Background technique

China has solemnly promised to the world that by 2020, China's carbon dioxide emissions per unit of GDP will fall by 40% to 45% compared with 2005. The total amount of biomass energy (including municipal solid waste) that can be developed in China is about 500 million tons of standard coal in the near future. Biomass power generation can meet more than 20% of China's energy consumption, and can reduce carbon dioxide emissions by nearly 3. 500 million tons, sulfur dioxide, nitrogen oxides, soot emissions reduction of nearly 25 million tons. Therefore, the development and utilization of biomass energy must be accelerated. Straw fuel can be divided into yellow straw (straw grass, wheat straw, corn stover, etc.), white straw (cotton stalk, hemp stalk, rape stalk, peanut shell, etc.), gray straw (forest tree branches, bark and other forestry waste), black straw (waste after industrial processing). They have high volatile matter, high water content, high content of alkali metals such as chlorine, potassium and sodium, low calorific value and low ash melting point. At present, the most successful biomass straw fuel boilers in the world use grate-type structures. The boiler system has high investment and the core technologies are in foreign companies. The technology of domestically burned straw boilers has just started. The fluidized bed and circulating fluidized bed biomass boilers that have been put into operation have coking, convective heating area ash, poor boiler fuel adaptability, unstable operation, and severe superheater corrosion. Technical difficulties have restricted the large-scale promotion of biomass boilers to high parameters. The Chinese patent (ZL01249503.4) is a "differential fluidized bed boiler for incineration of waste" developed by our company. The patent provides the structure of biofuels such as aldehyde residue and rice husk. In practice, biofuels have the characteristics of seasonal and agricultural production diversity supply, which causes problems in boiler feed, requiring boilers to burn mixed fuels, because different biomass fuels contain elements such as K, Na, CI, etc. The content varies greatly. When the boiler burns mixed fuel, it causes ash and corrosion of the superheater. At the same time, the biomass fuel will inevitably be mixed with large inert materials during the collection process, so there are problems such as superheater corrosion and poor slagging. Affect the long-term safe and stable operation of the boiler.

In addition, in the waste incineration fluidized bed boiler, there are also problems such as ash deposition and corrosion of the superheater, and poor slagging.

Summary of the invention

The object of the present invention is to provide a high-efficiency differential multi-swirl cone bed structure for burning biomass or garbage fuel boilers, focusing on the corrosion of the superheater encountered by the boiler, and burning various biomass and fuel. The problems of poor fuel adaptability and poor slagging caused by the intensive bulk materials in the middle are solved at the same time to solve the problems of improving the combustion efficiency of the fuel and reducing the wear of the heated surface.

The high-efficiency differential multi-swirl cone bed air distribution structure for burning biomass or garbage comprises a stepped arrangement of a high speed bed and a low speed bed, a V-shaped air distribution plate and a plurality of conical air distribution chambers, Immersion heating surface, negative pressure feeder, multi-layer swirling tertiary air, inert material, etc.

The content of the invention is:

1. Due to the large difference in density, particle size, moisture, and burning rate of different biomasses, in order to satisfy a variety of biomass burning, different bed surfaces are arranged in a stepwise manner, and at the same time, the fluidization speed of the bed surface is different, low For high-speed beds, the high position is a low-speed bed. After the fuel enters the high-speed bed through the feeder, large particles and dense fuel and inert materials flow in the high-speed bed. And low-density and fine-grained materials and fuel enter the low-speed bed; due to the difference in flow velocity between the high-speed bed and the low-speed bed, the first internal circulation flow of the high-speed bed and the low-speed bed is formed to meet the combustion requirements of different biomass fuels. .

2. The collection of biomass after bulk crushing will inevitably be mixed with large inert materials, especially the large inert materials in the living garbage. In a fluidized bed boiler, a large amount of inert material directly causes a boiler to malfunction, so it is important to remove large inert materials in time. The invention provides a high-speed bed as an air distribution device combining a V-shaped air distribution plate and a plurality of conical air distribution chambers, and a V-shaped row disposed between the bottom of the two V-shaped air distribution plates and the two conical air distribution chambers The slag is arranged, and a T-shaped hood that is blown downward is arranged on the V-shaped air distribution plate, and the cooperation between the T-shaped hoods forms a flat plate. When the fluidized wind enters the hearth through the conical air chamber and the T-shaped hood, the fluidized air is swept downward through the small hole of the T-shaped hood, and the fluidized wind flows upward after entering the hearth, so the upward flow of the hearth The downward sweeping air with the small hole of the T-shaped hood forms a second inner circulation stream. This internal swirl helps to separate the large inert material and smoothly exits the large-diameter V-shaped slag set at the bottom of the inclined cloth.

3. Set three times of multiple winds in the furnace to arrange the third wind. The three winds are tangentially arranged downward to form a tangential swirl, which is the third inner circulation flow. This tertiary cyclone helps to increase the burn-up rate of biomass fuels and reduce emissions of NOx pollutants.

4. The content of K, Na, CI and other elements in biomass and garbage is large. The high content of K and Na will cause the ash melting point to decrease, which will bring about the serious accumulation of convection heating surface, and the product of convection heating surface. Ash greatly improves the corrosion of the pipe and seriously affects the safe and stable operation of the boiler. The corrosion of the heated surface tube is related to the ash accumulation, the wall temperature and the concentration of harmful elements. The higher the temperature of the tube wall at a certain concentration, the more severe the corrosion, the ash accumulation and the ash accumulation. Corrosion rates differ by more than 15 times, which limits the development of boilers to high superheater parameters. Since K, Na, CI and other elements volatilize at a high temperature, the rate is extremely fast. The invention adopts a negative pressure feeding mode in which a certain height is arranged, and the superheater is arranged on the dense phase zone of the low speed bed. The fuel enters the high-speed bed from the negative pressure feeder. During the fuel drop process, most of the elements such as K, Na, CI in the furnace are volatilized into the rising flue gas, and the remaining part is further in the high-speed bed. Volatilization, so the concentration of harmful elements entering the low-speed bed is small and will not constitute corrosion to the superheater disposed on the dense phase of the low-speed bed.

The invention is realized by the invention, which comprises a high speed bed, a low speed bed, a V-shaped slag discharge device, a low speed bed plenum, a soaking heating surface tube, a soaking superheater, a conical air chamber, a T-shaped hood, a V-shaped air distribution panel. The negative pressure feeder is characterized in that a high and low stepped bed surface is arranged in the boiler furnace, the low position is a high speed bed, and the high position is a low speed bed; the high speed bed adopts a structure of a V-shaped air distribution plate and a plurality of conical air distribution chambers. a large-diameter V-shaped slag discharge device is arranged between the bottom of the two V-shaped air distribution plates and the two conical air distribution chambers; the immersed heating surface tube and the soaking superheater are arranged on the low-speed bed, and the V-shaped air distribution plate is provided with a plurality of T-shaped shapes. Under the hood, the low speed bed is a low speed air chamber, and the upper end of the side wall of the furnace is respectively provided with a negative pressure feeder and a multi-layer swirling three air supply port. The high-pressure fluidized wind enters the furnace from the conical air chamber through the V-shaped air distribution plate and the T-shaped hood arranged thereon, and the low-pressure fluidized air enters the furnace from the low-speed air chamber; the biomass fuel includes garbage from the negative pressure feeder Into the high-speed bed, the inert material of the biomass fuel and the bed surface is fluidized at a high speed by the fluidizing wind, and forms a top-down internal circulation flow with the low-speed bed material. Bulk inert material is discharged through a large diameter V-shaped slag discharger.

A T-shaped hood that is blown down by a small hole is arranged on the V-shaped air distribution plate and has a flat plate shape. The internal circulation flow fluidized bed system formed by the step height difference formed by the high speed bed and the low speed bed can be full Partition burning of a variety of biomass with different densities and non-particle sizes. A low-speed bed and a V-shaped air distribution plate and a plurality of conical air chambers and a mating structure formed between the T-shaped hoods disposed thereon. The superheater is arranged on the low speed bed to form a structure of the soaking superheater, and at the same time, the soaking and heating surface tube can be arranged on the low speed bed for burning fuel such as biomass and domestic garbage to solve the problem of superheater corrosion. The high-speed bed adopts a V-shaped air distribution plate and a plurality of conical air distribution chambers, and a V-shaped slag discharger structure disposed between the bottom of the two V-shaped air distribution plates and the two conical air distribution chambers, and is used for burning bulk inertia Fuels such as biomass and domestic waste.

V-shaped air distribution plate and conical air distribution chamber, and single or multiple arrays of structural forms. The T-shaped hood is tilted on both sides of the front and rear, and a small hole is obliquely opened on the hood of the hood. The technical effect of the invention is: It can effectively solve the technical problems such as ash collection, corrosion and slag discharge caused by burning biomass or garbage, and at the same time, has strong advantages in improving combustion efficiency and reducing wear of immersion heating surface. Superiority. DRAWINGS

Figure 1 is a side view of the present invention.

Figure 2 is another side view of the present invention.

3 is a schematic structural view of a T-shaped hood according to the present invention. Figure 4 is a cross-sectional view of the T-shaped hood of the present invention. In the figure, 1, high-speed bed 2, low-speed bed 3, V-shaped slag discharger 4, low-speed bed plenum 5, soaked heating surface tube 6, soaking superheater 7, multi-layer swirling three air supply port 8, conical cloth The air chamber 9, the T-shaped hood 10, the V-shaped air distribution plate 11, the negative pressure feeder 12, and the furnace. detailed description As shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, the present invention is realized by providing a high and low stepped bed surface in the boiler furnace 12, the low position is the high speed bed 1, and the high position is the low speed bed 2; The structure of the V-shaped air distribution plate 10 and the plurality of conical air distribution chambers 8 is adopted, and a large-diameter V-shaped slag discharge device 3 is disposed between the bottom of the two V-shaped air distribution plates 10 and the two conical air distribution chambers 8; the low-speed bed 2 The soaking heating surface tube 5 and the soaking superheater 6 are arranged on the top, and the V-shaped air distribution plate 10 is provided with a plurality of T-shaped hoods 9, the low speed bed 2 is below the low speed air chamber 4, and the upper end of the side wall of the furnace 12 is respectively provided with a negative pressure The feeder 11 and the multi-layer swirling tertiary air supply port 7, the high-pressure fluidizing wind enters the furnace from the conical air chamber 8 through the V-shaped air distribution plate 10 and the T-shaped hood 9 disposed thereon, in the V-shaped cloth wind The plate 10 is provided with a T-shaped hood 9 with a small hole downwardly blown, and the T-shaped hood 9 is arranged in a flat shape on the V-shaped air distribution plate 10; the low-pressure fluidized wind enters the furnace from the low-speed air chamber 4; the biomass fuel includes The garbage enters the high-speed bed 1 from the negative pressure feeder 11, and the negative pressure feeder 11 is 2-3 meters away from the high-speed bed surface, and the inert material of the biomass fuel and the bed surface is Under the action of the high velocity stream of air, circulating flow is formed in the top-down bed 2 to the low speed material. The upper part of the V-shaped slag discharger 3 disposed between the bottom of the two V-shaped air distribution plates 10 and the two conical air distribution chambers 8 is a slag discharge groove having a width of 150 to 400 mm which is the same width as the high speed bed 1, and the lower portion passes through a slag discharge groove The front and rear sides are inclined downwardly to take out, and the bulk inert material is discharged through the outlet. The high speed bed 1 air distribution structure is embodied in the form of a V-shaped air distribution plate 10 and a conical air distribution chamber 8, and a single or a plurality of arranged structures. A T-shaped hood 9 disposed on the V-shaped air distribution plate 10, and a T-shaped hood 9 are arranged in a flat plate shape on the V-shaped air distribution plate 10. The structure of the T-shaped (or T-shaped) hood 9 is inclined on the front and rear sides to facilitate the expansion of the fit between the hoods, and a plurality of small holes are obliquely opened on the hood of the hood, and the size and number of the openings are set according to different flow rates.

Claims

Claim

1. A high-efficiency differential multi-swirl conical bed air distribution structure for a biomass or waste-fuel boiler, which comprises a high-speed bed, a low-speed bed, a V-shaped slag discharge device, a low-speed bed plenum, a soaked heating surface tube, and a soaking Superheater, conical air chamber, T-shaped hood, V-shaped air distribution plate, negative pressure feeder, characterized in that a high-low stepped bed surface is arranged in the boiler furnace, the low position is a high-speed bed, and the high position is a low-speed bed; The high-speed bed adopts a structure of a V-shaped air distribution plate and a plurality of conical air distribution chambers, and a large-diameter V-shaped slag discharge device is arranged between the bottom of the two V-shaped air distribution plates and the two conical air distribution chambers; the soaking heating surface is arranged on the low-speed bed The tube and the soaking superheater are provided with a plurality of T-shaped hoods on the V-shaped air distribution plate, and a low-speed air chamber below the low-speed bed, and a negative pressure feeder and a multi-layer swirling three-way air supply port respectively at the upper end of the furnace side wall.

2. A high efficiency differential multi-swirl conical bed air distribution structure for a biomass-fired or waste-fuel boiler according to claim 1, characterized in that a small hole is blown down on the V-shaped air distribution plate. The T-shaped hood has a flat shape.

3. A multi-swirl multi-swirl conical bed wind structure for a biomass-fired or waste-fuel boiler according to claim 1, wherein the T-shaped hood is inclined on both sides of the front and rear, and the head is flat on the hood. Open several small holes diagonally.