Combustion adjustment method of a supercritical boiler mixed with coke oven gas

Abstract

The invention discloses a combustion adjustment method for a supercritical boiler capable of performing blending combustion of coke oven gas. The device comprises a supercritical boiler capable of performing blending combustion of coke oven gas. The combustion adjustment method comprises the following steps: adopting nonlinear normal pagoda type air door air distribution openings by virtue of an eight-layer secondary air door, sequentially reducing the air door opening upwards, allowing the air door opening of a burnout air door at a diagonal part to be smaller than the air door opening at another diagonal part, and feeding two layers of secondary air at least by virtue of a gas gun by adopting a normal pagoda type air distribution mode. The normal pagoda type air door distribution opening of the secondary air door and different air door openings at two diagonal parts of the burnout air door are adopted, and multilayer air is fed by virtue of the gas gun, so that the fume temperature deviation at the hearth outlet can be effectively reduced, and the detonation accidents of the boiler are reduced. Moreover, according to stable combustion in a fuel enriched area on the middle lower part of the hearth and feeding of the gas gun, the NOx generation amount is greatly reduced, the boiler operates in a high-efficiency economic performance area, the comprehensive operating cost is reduced, and the adjustment method is simple.

Description

technical field [0001] The invention relates to a combustion adjustment method of a supercritical boiler mixed with coke oven gas, in particular to the different air distribution adjustment methods of the secondary air and the overburned air of the supercritical boiler and the operation mode of each layer of gas guns, belonging to the four-corner cutting method. Round boiler combustion technology field. Background technique [0002] The boiler burner of a supercritical unit adopts the wall-type tangential combustion method. A coke oven gas mixed combustion system device is installed in the secondary air nozzle of each set of burner layers. There are 12 gas guns designed, each with an output of 3000 Nm³ / h, the total output is 36000 Nm³ / h, calculated according to the coke oven gas calorific value of 17~19MJ / Nm³, it is estimated that 20 tons of standard coal can be saved per hour, and the combustion stability and economy of the boiler are greatly enhanced. It has been put int...

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Problems solved by technology

[0002] The boiler burner of a supercritical unit adopts the wall-type tangential combustion method. A coke oven gas mixed combustion system device is installed in the secondary air nozzle of each set of burner layers. There are 12 gas guns designed, each with an output of 3000 Nm³ / h, the total output is 36000 Nm³ / h, calculated according to the coke oven gas calorific value of 17~19MJ / Nm³, it is estimated that 20 tons of standard coal can be saved per hour, and the combustion stability and economy of the boiler are greatly enhanced. It has been put into production, but only the lowest layer of gas guns has been used in the four-layer gas mixed combustion system of the boiler, and the remaining 3 layers of gas guns have never been used. The NO x The concentration is also relatively large (about 500 mg / m 3 ), there is still a certain deviation from the emission standards stipulated by the state, which increases the operating cost of the denitrification device. At present, the equal air distribution method of maintaining the same opening degree of the secondary dampers on each floor is adopted in the operation of the power plant, and the burnout dampers at the four corners also maintain the same Opening, such an operation mode does not form air staged combustion in the main combustion zone of the furnace, which is not conducive to reducing NO x The amount of generation, and there is a large difference in smoke temperature between the left and right sides of the furnace outlet, which is likely to cause a large thermal deviation between the tube panels on the heating surface, resulting in uneven heating of the tube walls of some tubes, uneven distribution of steam flow in the tube, and finally causing the heating surface of the tube Leakage of the overheated squib caused equipment and personal safety accidents

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