Air-water combined cooling and dry slag removal method and system for pulverized coal boiler

Abstract

The invention relates to an air-water combined cooling dry slagging method and a system of a pulverized coal boiler. The method comprises the following steps of primarily adopting an air-cooling steel-strip (chain plate) slag cooling machine to pre-cool and withdraw the slag of the boiler; adopting a roller-type slag cooler to further cool the slag after precooling; and finally directly transporting or conveying the slag after being cooled through the roller-type slag cooler to a slag cabin. The slag from the boiler is conveyed to a transitional slag bucket through the air-cooling steel-strip slag cooling machine, then the slag enters the roller-type slag cooler, and finally the hot air being heated by the slag enters a boiler hearth to be burned. The cooling water of the rotary-type slag cooler is from a condensed water (or other cooling medium) system in a power plant, and the cooling water is returned to a heat power system of the power plant after being heated by the slag. Due to the adoption of the method and the system, the problems that the air volume of a dry slagging system is difficult to control and side effect is produced on the burning of the boiler can be solved, the waste heat of the slag can be recycled, the unit efficiency can be improved, and the power generation coal consumption can be reduced.

Description

Technical field [0001] The invention relates to thermal power generation, in particular to a method and system for cooling slag of a pulverized coal boiler in a thermal power plant. Background technique [0002] For the mechanical slag removal system of pulverized coal boilers in thermal power plants, there are two mainstream technologies at home and abroad. One is the use of wet scraper slag removal system, and the other is the use of air-cooled steel belt (chain plate). The machine’s dry slagging system. [0003] figure 1 It shows the system composition diagram of a typical wet slag removal system of a scraper slag conveyor. Such as figure 1 As shown, the equipment of the wet slag removal system of the scraper slag conveyor is mainly composed of the water-immersed scraper slag conveyor 2, the slag conveyor from the slag conveyor to the slag bin 3, the slag bin 4, the overflow pool 5, the sedimentation tank or It is composed of high-efficiency thickener 6, buffer pool 7, and rel...

AI Technical Summary

Problems solved by technology

Its main disadvantages are: high power consumption, huge slag waste heat cannot be used, high water consumption in operation, and complicated water system; the water in the lower tank of the furnace evaporates to absorb the heat of the furnace, and is discharged together with the flue gas, wasting part of the energy loss

According to Fan Rendong of Jiangsu Provincial Electric Power Design Institute, "Test and Analysis of the Effect of Air-cooled Dry Slag Discharge System on Boiler Efficiency", the dry slag discharge system will reduce the furnace efficiency by 0.3% to 0.5% in the case of a large amount of slag.

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