Soot blowing system and process of thermal power generation coal-fired boiler

Abstract

The invention discloses a soot blowing system of a thermal power generation coal-fired boiler. The soot blowing system comprises a centrifugal air compressor (1), a first storage tank control valve (6), a second storage tank control valve (7), a third storage tank control valve (8), a cooler (5), a compressed air storage tank (4), a soot blowing control valve (2) and a soot blower (3); the outputof centrifugal air compressor is divided into two branches, wherein the first branch is sequentially connected with the first storage tank control valve, the soot blowing control valve and the soot blower and finally reaches a hearth to blow soot; and the second branch is sequentially connected with the second storage tank control valve, the cooler, the compressed air storage tank and the third storage tank control valve and then is connected into a pipeline between the first storage tank control valve and the soot blowing control valve of the first branch. According to the soot blowing systemof the thermal power generation coal-fired boiler, the compressed high-temperature compressed air serves as a soot blowing medium and flows out at local sound velocity after passing through a nozzleof the soot blower, then jet impact is generated on accumulated soot in the hearth, the accumulated soot is cleaned from the interior of the hearth, the purpose of soot blowing and cleaning of the boiler is achieved, the problems of water accumulation, scouring damage, high energy consumption and the like of an existing steam soot blowing system are solved, and obvious technical effect is achieved.

Description

technical field [0001] The invention relates to a coal-fired boiler soot blowing system for thermal power generation. The present invention also relates to a soot-blowing process of a coal-fired boiler for thermal power generation based on the above system. Background technique [0002] When the boiler of the thermal power coal-fired unit is running, in order to ensure that there is no ash accumulation inside the furnace to reduce the heat exchange efficiency and prevent coking on each heating surface, superheated steam is usually used to carry out online purging of the heating surface inside the furnace to remove the accumulated dust. Soot cleaned up. [0003] The use of superheated steam for purging mainly uses superheated steam as a source of steam taken from the boiler itself, which is easy to obtain, and considering the relatively high pressure of superheated steam, its purging effect can be guaranteed to a certain extent. [0004] Under normal working conditions, it ...

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Problems solved by technology

[0006] 1) Insufficient superheated degree of superheated steam

When the superheated degree of superheated steam is insufficient, the superheated steam ejected from the steam soot blowing system will quickly reduce the pressure and temperature, and the soot blowing steam on the surface of the heating surface will carry water, and the ash particles mixed on the surface will strongly scour the heating surface. Long-term soot blowing causes the wall thickness of the heat exchange pipe on the heating surface to be thinned, reducing the reliability of the boiler

[0007] 2) Before boiler soot blowing, it is necessary to fully drain the water in each pipeline of the steam soot blowing system. If the water is not fully drained, it will cause the soot blowing steam source entering the furnace to carry water, which will directly produce a strong impact on the heating surface. scour

[0008] 3) Steam soot blowing system The superheated steam entering the furnace during soot blowing is cooled down, heated to a higher temperature by the coal burning in the furnace, and then enters the flue gas system at the boiler outlet in turn, and is overheated at 130-150°C The state of the steam is discharged from the furnace, and the internal energy of this part of the superheated steam is completely wasted, reducing the economical efficiency of the unit

[0009] That is to say: when the power generation load of the generator set is low, the source parameters of the steam source decrease, so that the steam pressure of the soot blowing steam source cannot meet the parameter requirements of the soot blower, and the soot blowing of the boiler furnace cannot be performed, and the heating surface of the boiler is more prone to ash accumulation , coking

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