A method for increasing the hot primary air temperature of a high-moisture coal-fired boiler

Abstract

The invention discloses a method for improving the heat primary air temperature of a boiler with high moisture coal burned. Walls on the two sides of a rear smoke channel in the area of a low temperature reheater or a low temperature superheater of the boiler are respectively provided with an opening. A hot flue gas leading-out pipe is installed at the openings and is led to an inlet of a primary air pre-heater. Due to the fact that the pressure of an inlet and the pressure of an outlet of the hot flue gas leading-out pipe are different, the produced pressure difference drives hot flue gas to flow into the primary air pre-heater via the hot flue gas leading-out pipe from the area of the low temperature reheater or the low temperature superheater of the boiler, and the heat primary air temperature, the grinding inlet temperature and the grinding outlet temperature are improved remarkably. By means of the method, when the high moisture coal is applied to the power station boiler, the heat primary air temperature, the grinding inlet temperature and the grinding outlet temperature are improved, the requirement for safety operation of a coal mill can be met, meanwhile, a steam-water system of the boiler is normal, discharging of NOx is normal, the safety operation of the boiler is improved, the structure of a device is reasonable, investment is small, operation cost is low, and the method is suitable for the situation of China.

Description

technical field [0001] The invention belongs to the technical field of boiler combustion, relates to the combustion application of high-moisture coal in power plant boilers, and particularly relates to a method for increasing the temperature of hot primary air in boilers burning high-moisture coal. Background technique [0002] my country is rich in coal resources. For a long time, coal has always occupied a dominant position in my country's energy production and consumption. According to statistics, coal accounts for 76% of the country's total primary energy output and 75% of the total primary energy consumption. Coal thermal power generation is also the main form of my country's electricity production. With the rapid growth of my country's economy, the consumption of coal will increase, and the supply of coal will become more and more tense. In order to reduce operating costs, many boilers designed to use low-moisture, high-calorific-value bituminous coal in my country hav...

AI Technical Summary

Problems solved by technology

For units equipped with medium-speed grinding direct blowing pulverizing system and tubular air preheater, there is no simple and feasible method at present