Method for combusting high alkali metal coal

Abstract

The invention relates to a method for combusting high alkali metal coal. The high alkali metal coal is introduced into a fluidized bed boiler to be combusted, the bed temperature is set to be 780 DEG C-870 DEG C, by means of the temperature interval, stable combustion of the boiler can be guaranteed, a relatively low temperature can also be kept, the volatilization amount of alkali metal is effectively limited, the boiler can be controlled not to be coked, and contamination, corrosion and the like are reduced. Most alkali metal is contained in slag, can be discharged out of the boiler through a slag removal system and does not participate in boiler combustion. A material returning system adopts a steam cooling mode, on one hand, the bed temperature can be reasonably controlled, and meanwhile the temperature of circulating ash is also within a reasonable range. Part of tube panels are added on the heating surface of the fluidized bed boiler to ensure the main steam temperature and the reheat steam temperature. By means of the method, under the condition of 100% combustion of the high alkali metal coal, the problems of coking, corrosion, slagging and the like of the boiler can be reduced, and the utilization rate of the alkali metal coal can be increased. Meanwhile, large-scale transformation is not needed, and wide engineering application prospects are achieved.

Description

technical field

[0001] The invention belongs to the field of boiler combustion, and in particular relates to a method for burning high-alkali metal coal. Background technique

[0002] At present, the stock of high-alkaline coal in the Zhundong region of Xinjiang is about 400 billion tons, which is an important coal source base in my country in the future. However, the high alkaline elements such as sodium and potassium in coal will cause slagging, contamination, and Problems such as corrosion and dust accumulation seriously affect the safe operation of the boiler. At this stage, some existing methods can reduce the adverse effects of burning high-sodium-potassium coal on boiler combustion, but all of them have relatively large limitations. For example, the main methods for boilers to burn high-sodium-potassium coal at present are: 1. Mixed combustion. The coal type in the Zhundong region of Xinjiang is a typical high-sodium-potassium coal. Most of the power plant boilers in...

Examples

Embodiment Construction

[0019] The present invention will be further described in detail below in conjunction with specific embodiments.

[0020] A method of burning high-alkali metal coal, combined with the characteristics that the temperature has a great influence on the volatilization of alkali metals. Before 900°C, the volatilization amount is small, and after 900°C, the volatilization amount of sodium is nearly doubled. High alkali metal coal is burned at a temperature of 780°C to 870°C. In this temperature range, it can ensure the stable combustion of the boiler and maintain a relatively low temperature, thereby effectively limiting the volatilization of alkali metals, controlling the boiler from coking, reducing contamination, corrosion, etc.

[0021] A method for burning high-alkali metal coal. The high-alkali metal coal is fed into a fluidized bed boiler for combustion, the bed temperature is set at 780°C to 870°C, and the slag containing alkali metal is discharged without participating in t...

technical field

[0001] The invention belongs to the field of boiler combustion, and in particular relates to a method for burning high-alkali metal coal. Background technique

[0002] At present, the stock of high-alkaline coal in the Zhundong region of Xinjiang is about 400 billion tons, which is an important coal source base in my country in the future. However, the high alkaline elements such as sodium and potassium in coal will cause slagging, contamination, and Problems such as corrosion and dust accumulation seriously affect the safe operation of the boiler. At this stage, some existing methods can reduce the adverse effects of burning high-sodium-potassium coal on boiler combustion, but all of them have relatively large limitations. For example, the main methods for boilers to burn high-sodium-potassium coal at present are: 1. Mixed combustion. The coal type in the Zhundong region of Xinjiang is a typical high-sodium-potassium coal. Most of the power plant boilers in...

Examples

Embodiment Construction

[0019] The present invention will be further described in detail below in conjunction with specific embodiments.

[0020] A method of burning high-alkali metal coal, combined with the characteristics that the temperature has a great influence on the volatilization of alkali metals. Before 900°C, the volatilization amount is small, and after 900°C, the volatilization amount of sodium is nearly doubled. High alkali metal coal is burned at a temperature of 780°C to 870°C. In this temperature range, it can ensure the stable combustion of the boiler and maintain a relatively low temperature, thereby effectively limiting the volatilization of alkali metals, controlling the boiler from coking, reducing contamination, corrosion, etc.

[0021] A method for burning high-alkali metal coal. The high-alkali metal coal is fed into a fluidized bed boiler for combustion, the bed temperature is set at 780°C to 870°C, and the slag containing alkali metal is discharged without participating in t...