Against air-cooled dry-type slag extractor system

numerical simulation is carried out to study the influence of boiler bottom air leakage on temperature field

burn-out rate

NOx production at typical loads. The results indicate that

after the cold air leaks from dry-type slag extractorthe overall temperature level in the furnace decreases

which has a great effect on combustion stability of the middle and lower burner layers

and the flue gas temperature at the center section of the bottom burner can be reduced by 100 K at low load. Meanwhile

the coal incomplete combustion loss and NO_x production also rises. The influence of air leakage can not be ignored especially when the system is poorly sealed. The exhaust gas temperature rises markedly because X ratio of the air preheater decreases after the boiler bottom air leakage happens.