1050 MW ultra-supercritical pulverized coal boiler anti-overtemperature control method

Abstract

The invention relates to a 1050 MW ultra-supercritical pulverized coal boiler anti-overtemperature control method. According to the method, a burner burns stably by controlling the operating sequence of a coal pulverizer, the opening degrees of secondary air doors from the top layer to the last but one layer are sequentially decreased by controlling the secondary air distribution mode, the temperature of a hearth outlet is effectively decreased, distribution non-uniformity of the inner wall of a hearth is reduced, the opening degree of a secondary air door on the bottom layer is 30%, and therefore flames are supported not to rush downwards and prevented from falling into a dry bottom hopper. The primary air speed of a powder discharge pipe of the coal pulverizer ranges from 20 m / s to 30 m / s, the opening degrees of auxiliary air doors range from 35% to 45%, the secondary air volume can be reduced by increasing the primary air volume in the hearth, and the probability that secondary air impacts primary air powder on the opposite side due to the too high secondary air speed, so that wall-attached burning is caused is avoided. The control method conforms to octagonal reverse bi-tangential circle boiler power field characteristics, pulverized coal is fully burnt, and therefore the pipe explosion accident caused by overtemperature generated due to non-uniform inner wall temperature distribution is avoided.

Description

technical field [0001] The invention relates to the field of ultra-supercritical pulverized coal boilers in thermal power plants, in particular to an anti-overtemperature control method for 1050 megawatt ultra-supercritical pulverized coal boilers. Background technique [0002] Ultra-supercritical boilers refer to boilers with a working fluid pressure above 26MPa. Ultra-supercritical boilers have significant energy-saving and environmental-improving effects. Therefore, they are widely used in thermal power plants. Take the 1050 MW ultra-supercritical pulverized coal boiler of model HG-3100 / 28.25-YM4 manufactured by Harbin Boiler Works Co., Ltd. as an example. It adopts a П-shaped layout, a single furnace, an intermediate reheating, and a low-NOX main burner. And high-level burn-off air graded combustion technology, octagonal reverse double tangential circular combustion method, the furnace is an internal thread tube vertical rising membrane water wall, and the atmosphere exp...

AI Technical Summary

Problems solved by technology

The size and position of the tangent circle are affected by the primary air and secondary air. Improper primary air, secondary air and improper wind speed will affect the position and size of the tangent circle, which will easily cause uneven temperature distribution in the furnace and local Superheater Tube Explosion Accident Caused by Over-temperature

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