Abstract:When the draught fan fault of waste heat utilization system occurs, the flue gas could not be discharged through normal system and it need open the flue gas damper of waste heat boiler quickly. In addition, the abnormal discharge of flue gas may lead to the variation of back pressure at gas turbine outlet, and then trigger the back pressure protection of gas turbine. Based on the established physical and mathematical models, this paper evaluated three operating conditions of full fault, semi fault and unit fault of draught fan, and pointed out that the unit fault had little influence on the whole system. If the flue gas damper of waste heat boiler is opened in 15 seconds, the back pressure at gas turbine outlet could be kept normal basically.

Keywords:gas turbine, waste heat utilization, flue gas damper, draught fan fault, backpressure