Effects of rotary air preheater leakage on steam power plants performance

The effects of air leakage in the rotary air preheater on performance of steam power plants, such as fuel and power consumption, is an interesting subject in economical maintenance planning. In this paper, the analytical equations to determine the air leakage effects on the fuel consumption and consumed power of forced and induced draft fans in the steam power plants are developed. To show the rotary air preheater leakage effects, four units of 1000 MW Shahid Rajaei steam power plant were tested based on ASME PTC 4.1 and 4.3. The results show that, the air leakages average in these units have increased to 24.7% and 28.0% for natural gas and heavy oil fired fuels, respectively. According to the developed analytical equations, the fuel and power consumption increased to 850 ton/month, and 1078 kW for heavy oil and negligible variation of fuel consumption, and 834 kW for natural gas fuels firing, respectively, Therefore, higher fuel and power conservation can be obtained by proper planning to maintain the rotary air preheaters in suitable conditions.