Boiler start-up method to prevent scale formation and secondary combustion accidents in tail flue of 1000mw octagonal tangential boiler

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 starting method of a boiler in a power station, in particular to a starting method for preventing scale formation and secondary combustion accidents in a tail flue of a 1000MW octagonal tangential boiler. Background technique [0002] Tube bursting on the heating surface of boilers is one of the major problems that endanger the safe operation of boilers in thermal power plants, and tube bursting on the heating surface of boilers has a lot to do with the material of the heating surface, and overheating of the heating surface is one of the main reasons. Over-temperature accidents on the heating surface of boilers that have been in operation for a long time are mainly due to the uneven distribution of boiler heat load and the formation and shedding of oxide scales on the heating surface, which cause blockage of the heating surface tubes, resulting in poor flow of working fluid and excess heat. It is taken away by the working med...

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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