Improving the Seals of Air Heaters to Reduce the Air Inflow

Анотація

A fraction of air that overflows to the flow of effluent combustion gases defines the operation efficiency of air heater and affects the efficiency factor of steam generating unit. The test data show that the cross- flows of air and effluent gases in the regenerative air heater (RAH) in the case of operation of TGM-96B boiler are actually higher than 40%. The leakages in the RAH result in a decrease of the power of energy generating unit, because air cross-flows to the gas section of the RAH result in the restricted boiler loading with regard to the efficiency of smoke suckers and fans and also in increased expenditures of energy for the auxiliaries. Consideration was given to the issues related to the clearance control system in the seals of regenerative air heaters. The available seal structure is inefficient due to the impossibility of appropriate adjustment and maintenance of required running clearances in the seals. A placement of new innovative system of seals allows for the reduction of air inflow to the level of 12 to 15 % and as a result an increase in the boiler efficiency, a reduction of energy expenditures for auxiliaries providing  a stable behavior of the air heater and increasing the reliability of it and the longevity of its components.