Experimental Study on Combustion Optimization and Adjustment of 2070t/h Supercritical Opposed Flame Coal-fired Boiler

Taking a 2070t/h supercritical opposed flame coal-fired boiler in a power plant as the research object, through the adjustment test of over-fire air and the adjustment test of coal mill shutdown mode under mutative load based on mixed coal combustion, to study the effects of over-fire air and coal mill shutdown mode on boiler combustion and combustion efficiency. The research results show that under rated load, the lower opening of the over-fire air is 100%, and the upper air door opening of the over-fire air is 40%; different coal mills should be used in the combustion of mixed coal, burning coal with higher volatile content in the burner below. When the boiler is running under reduced load, the upper burner should be stopped first, and take precedence to the close A mill (upper front wall burner), which is conducive to the stable ignition and combustion of the coal powder, improve combustion efficiency and reduce pollutant emission. Carbon content in fly ash decreased from 12.3 % to 6.3 % on average, the CO content decreased by 38.5mg/m ³ , the NO x content by 452mg/m ³ , and the SO 2 content by 105mg/m ³ .