Thermal state research method for improving flame center deflection of corner tangential boiler

Abstract

The invention provides a thermal state research method for improving flame center deflection of a corner tangential boiler, and the method can improve the operation economy and safety of a unit. The method comprises the following steps that when a boiler runs, the proportion of burnout air and secondary air of a low-nitrogen combustor is designed, and the actual proportion difference is rechecked; performing temperature-state ventilation on the coal mill after shutdown, measuring the air volume of each powder pipe under three air volume working conditions, and checking the air volume of the coal mill; measuring the air volume of each powder pipe in a hot state of the running coal mill one by one under three air volume working conditions, and checking the air volume of the coal mill; pulverized coal is sampled and weighed within the set time, meanwhile, a backrest pipe is used for measuring the speed of pulverized coal airflow under the working condition of a coal mill, and shrinkage cavities are used for conducting primary air thermal state leveling on the same layer; the auxiliary air door distributes air to a smoke temperature field and an oxygen field at an outlet of the economizer in different modes; an SOFA air door, a fuel air door and a main combustor swing angle are used for measuring a smoke temperature field and an oxygen amount field at an outlet of the economizer under different opening degrees.

Description

technical field [0001] The invention relates to a thermal state research method for improving the deflection of the flame center of a four-corner tangential boiler, belonging to the field of coal-fired power plants, and can improve and reduce high-temperature corrosion, coking, and superheater steam temperature of a coal-fired boiler arranged at four corners of a burner. deviation and reduce the water level deviation on both sides of the drum boiler. Background technique [0002] Large and medium-sized coal-fired power plants have a large number of boilers with four-corner tangential combustion. The burners of this type of boiler are arranged at the four corners of the water-cooled wall. In theory, the flame center of this type of boiler is located in the center of the furnace, and the heating surfaces such as the water-cooled wall will not be affected by the flame deflection. However, in actual operation, affected by the burner installation, pulverizing system, and second...

AI Technical Summary

Problems solved by technology

[0002] Large and medium-sized coal-fired power plants have a large number of four-corner tangential combustion boilers. The burners of this type of boiler are arranged at the four corners of the water wall. Theoretically, the flame center of this type of boiler is located in the center of the furnace. However, in actual operation, due to the influence of burner installation, pulverizing system, and secondary air distribution, the boilers have different degrees of flame center deflection, which leads to high-temperature corrosion of the water wall, coking of the boiler, deviation of the steam temperature of the superheater, and High-temperature corrosion, even water-cooled wall tube burst, boiler coking and fire extinguishing, etc. endanger the safety of the unit

At present, boilers often adopt a low-nitrogen combustion method. Under this combustion method, the center of the flame moves upward, and the flame is prone to deflection. The invention patent "a cold-state research method for adjusting the smoke temperature deviation on both sides of a four-corner tangential boiler" application publication number CN111664443 A , to conduct relevant discussions on the deviation of smoke temperature on both sides of the four-corner tangentially circular boiler, "A Method for Adjusting the Flame Center Offset of Four-Corner Tangentially Circular Boiler" Application Publication No. CN110195860 B, individual research results can be used as the basis for improving and adjusting the deflection of the boiler flame center method, but the above-mentioned inventions either only carry out relevant research in the cold state, do not involve the hot state too much, or are biased towards theoretical research, and the engineering practice needs to be further verified. For this reason, there is an urgent need for a practical, reliable and easy method. It is a practical and generalizable engineering practice method to solve the problem of deflection of the flame center of the four-corner tangential circle boiler, and practice has proved that the thermal state adjustment method is safe and reliable by observing the boiler parameters and auxiliary instrument measurement in the thermal state research

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