Boiler starting method for preventing oxide skin generation of 1,000 MW octagonal tangent circle boiler and secondary combustion accident of tail flue

Abstract

The invention discloses a boiler starting method for preventing oxide skin generation of a 1,000 MW octagonal tangent circle boiler and a secondary combustion accident of a tail flue. Boiler warming is carried out before a combustor is put into operation, then, the combustor is put into operation, and the operation of the combustor is adopted according to the following operation principles that all large oil guns in an AB layer and part of large oil guns in a CD layer are put one by one, and when the outlet pressure of a boiler steam-water separator reaches 0.3 MPa, all micro oil guns in an A layer are put, and then a powder manufacturing system of the A layer is put into operation; and at the thermal state flushing and temperature rising and boosting stage, part of or all large oil guns quit one by one according to the pulverized coal combustion situation, and at the load rising stage, powder manufacturing systems are put into operation layer by layer according to the load situation. According to the method, the temperature rising rate of a heating surface of the boiler in the starting process can be controlled, and the good combustion effect of the pulverized coal in a hearth can be guaranteed; and generation of pipe oxide kin of the heating surface of the boiler is effectively prevented, and the purposes of preventing secondary combustion of the tail flue and the detonation accident of the hearth can be achieved.

Description

technical field [0001] The invention relates to a start-up method for a power station boiler, in particular to a boiler start-up method for preventing oxide scale formation and secondary combustion accidents in the tail flue of a 1000MW octagonal tangential boiler. Background technique [0002] The tube burst on the heating surface of the boiler is one of the major problems that endanger the safe operation of the boiler in the thermal power plant. In addition to the fact that the tube burst on the heating surface of the boiler is closely related to the material of the heating surface, the overheating of the heating surface is one of the main reasons. The over-temperature accident of the heating surface of the boiler in long-term operation is mainly due to the uneven distribution of the heat load of the boiler, and the formation and shedding of the oxide scale in the heating surface, which causes the blockage of the heating surface pipes, resulting in poor working fluid flow a...

AI Technical Summary

Problems solved by technology

During the cold start-up process of the unit, due to the low temperature of the heating surface of the boiler, if the micro-oil or plasma ignition system is directly used for pulverized coal operation, there will be three problems: First, the boiler directly operates pulverized coal. It is difficult to control the amount in a small range, and the heating rate of the heating surface of the boiler will increase rapidly. If it exceeds the normal heating rate specified by the heating surface, it will easily cause the production of scale in the heating surface tube; , the volume of the furnace is large, and the amount of fuel input is small during the start-up phase, which causes uneven heat load distribution in the furnace and easily causes local water-cooled walls to overheat; thirdly, due to the low temperature of the furnace, it is put into operation without sufficient preheating. Carrying pulverized coal will cause incomplete combustion of pulverized coal, and the kerosene mixture will deposit on the heating surface of the flue at the tail of the boiler, causing secondary combustion in the flue at the tail of the boiler. In addition, the accumulation of incompletely burned pulverized coal in the furnace can easily cause a furnace deflagration accident

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