Method for controlling flue gas temperature at brown coal boiler with downstream wet flue gas desulphurization, involves directly introducing cooling fluid into flue gas flow when actual temperature of flue gas exceeds reference value

摘要

The method involves measuring a flue gas temperature in a flow direction of flue gas behind a combustion air preheater (6) as an actual temperature. Cooling fluid e.g. water, is directly introduced into flue gas flow in the flow direction behind an economizer and before the preheater when the actual temperature of the flue gas exceeds a preset reference value for the temperature behind the preheater of 200 degree Celsius. The cooling fluid is ring-injected into the flue gas flow over a circumference of a smoke gas channel (8).