CN110885693A

CN110885693A - Coal slime airing method

Info

Publication number: CN110885693A
Application number: CN201911237783.4A
Authority: CN
Inventors: 赵维愚; 张春波; 王久生; 张建新; 刘熙旸; 周诗宇; 杨雪; 胡婧婷
Original assignee: State Grid Corp of China SGCC; Electric Power Research Institute of State Grid Jilin Electric Power Co Ltd
Current assignee: State Grid Corp of China SGCC; Electric Power Research Institute of State Grid Jilin Electric Power Co Ltd
Priority date: 2019-12-05
Filing date: 2019-12-05
Publication date: 2020-03-17

Abstract

The invention relates to a coal slime airing method, and belongs to coal slime airing methods of thermal power plants. Sampling the coal slime, and testing and analyzing the ash content and the total moisture content of the coal slime; accumulating and airing the coal slime with the dry base ash content of 35% -55%, wherein the accumulation height is 200-400 mm, and airing for 4-6 days; sampling and testing the coal slime, and finishing airing when the total moisture value of the coal slime is 10-13%. The advantages are that: the change of the coal quality after the coal slime is aired is analyzed, and the shortest time for airing the coal slime in the coal slime mixing and burning process is found out, so that the cost loss caused by airing the coal slime is reduced, and the use efficiency of the coal slime is improved. The invention has been put into practice in a plurality of thermal power plants using coal slime for mixing and burning and mixing, has good effect, saves the coal slime airing time, reduces the coal slime airing cost and improves the on-site production efficiency.

Description

Coal slime airing method

Technical Field

The invention belongs to a coal slime airing method for a thermal power plant, and is mainly used in the fields of coal slime mixed burning and inferior coal application of the thermal power plant.

Background

With the rapid development of the coal processing industry, the yield of the coal slime is obviously increased. Many power generation enterprises have gradually started to implement coal slime mixed combustion, and the problems of coal source shortage and high fuel cost are solved.

With the improvement of coal mining technology and processing technology, the classification of coal types is more and more fine. The raw coal is lifted up from the main shaft to enter the coal washing plant. The selected lump coal is called lump coal and is also called clean coal; the granulated coal slag and small coal blocks are also called as medium coal; finally, the coal ash and coal dust sinking to the water bottom are called coal slurry. The coal slime contains more clay minerals, and the water content is higher, the granularity is smaller, so most coal slime has high viscosity, and some coal slime also has certain fluidity. Due to the characteristics, coal blockage and coal blockage are easy to occur when the coal slime is mixed and burnt in the boiler, a plurality of unstable factors are brought to the operation of the boiler, and the problem that the coal slime is troublesome in the mixed burning process is also caused. In order to solve the problem, the coal slime is placed in the open ground for spreading and airing, and is put into a furnace for combustion after reaching a certain dry state, so that the phenomena of coal blockage and coal shed of an on-site coal bunker are solved, the calorific value can be improved through the airing of the coal slime, and the purchase of high-quality coal is reduced, thereby saving the fuel cost.

The water content, the quality and the heat productivity of the coal slime are changed after the coal slime is aired, and certain influence is generated on the quality price of the coal slime. Coal slime can be generally classified into 3 types according to the ash content and the heat value: the dry base ash content of the low-ash coal slime is 20-32%, and the low-grade heat value is 12.50 MJ/kg-20.00 MJ/kg; the dry base ash content of the medium-ash coal slime is 30-55 percent, and the low-grade heat value is 8.40 MJ/kg-12.50 MJ/kg; the dry basis ash content of the high-ash coal slime is higher than 55 percent, and the low calorific value is 3.50 MJ/kg-6.30 MJ/kg.

Disclosure of Invention

The invention provides a coal slime airing method, which aims to solve the problem of large coal slime airing loss in the airing process of medium-ash coal slime with a large amount of current use.

The technical scheme adopted by the invention is that the method comprises the following steps:

(1) sampling the coal slime, and testing and analyzing the ash content and the total moisture content of the coal slime;

(2) accumulating and airing the coal slime with the dry base ash content of 35% -55%, wherein the accumulation height is 200-400 mm, and airing for 4-6 days;

(3) sampling and testing the coal slime, and finishing airing when the total moisture value of the coal slime is 10-13%.

In the step (2) of the invention, the stacking height is 300 mm;

in the step (2), the coal slime is aired for 5 days;

in the step (3), the dry base ash is 35-45% of coal slime, and the heat value is improved by more than 4.20MJ/kg through airing;

in the step (3), the coal slime with dry-basis ash content of 45-55% is aired, and the heat value is increased by more than 2.30 MJ/kg.

The invention has the advantages that: the change of the coal quality after the coal slime is aired is analyzed, and the shortest time for airing the coal slime in the coal slime mixing and burning process is found out, so that the cost loss caused by airing the coal slime is reduced, and the use efficiency of the coal slime is improved. The invention has been put into practice in a plurality of thermal power plants using coal slime for mixing and burning and mixing, has good effect, saves the coal slime airing time, reduces the coal slime airing cost and improves the on-site production efficiency.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Comprises the following steps:

(2) stacking and airing the coal slime with the dry base ash content of 35 percent for 4 days, wherein the stacking height is 200;

(3) sampling and testing the coal slime, and finishing airing when the total moisture value of the coal slime is 10-13%;

after drying in the sun, the heat value is improved by more than 4.20 MJ/kg.

Example 2

Comprises the following steps:

(2) accumulating and airing the coal slime with the dry basis ash content of 45 percent for 5 days, wherein the accumulation height is 30 mm;

(3) sampling and testing the coal slime, finishing airing when the total moisture value of the coal slime is 10-13 percent,

after drying in the sun, the heat value is improved by more than 4.20 MJ/kg;

example 3

Comprises the following steps:

(2) stacking and airing the coal slime with the dry base ash content of 55% for 6 days, wherein the stacking height is 400 mm;

after drying in the sun, the heat value is improved by more than 2.30 MJ/kg.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A coal slime airing method is characterized by comprising the following steps:

2. The coal slime airing method according to claim 1, characterized by comprising the following steps: in the step (2), the stacking height is 300 mm.

3. The coal slime airing method according to claim 1, characterized by comprising the following steps: and (3) in the step (2), drying the coal slime for 5 days.

4. The coal slime airing method according to claim 1, characterized by comprising the following steps: in the step (3), the dry base ash is 35-45% of coal slime, and the heat value is improved by more than 4.20MJ/kg through airing.

5. The coal slime airing method according to claim 1, characterized by comprising the following steps: in the step (3), the coal slime with dry-basis ash content of 45-55% is aired, and the calorific value is increased by more than 2.30 MJ/kg.