Zhao B.,Zhejiang University |
Yang S.,Northeast Dianli University |
Zhang G.,Beifang Combined Electrical Power Co. |
Zhang H.,Beifang Combined Electrical Power Co. |
And 6 more authors.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2013
Direct air cooling (DAC) system has been widely applied in coal-fired power plants for its water-saving rate of 69%~84%. However, in arid regions with large sandstorm, the exhaust pressure of steam turbine will be raised by 8kPa or more because of the ash fouling of air cooled condenser (ACC). If it is not timely cleaned, the coal consumption of unit would elevate above 10~15 g/(kW·h) and the pollution emissions increases in the meantime. But the water consumption for timely cleaning is restricted by environmental conditions. To solve the incompatible contradiction, a novel compressed air blower (CAB) system was designed to clean the ash fouling for ACC in this paper, that is, the compressed air will entirely replace desalted water as cleaning medium for the new system. The main body of this paper includes the basic components of the CAB system, the content and results of a site simulation test (SST) for CAB under multi-operation conditions on an ACC of 600 MW DAC unit, the blowing evaluation indexes proposed, and the quantitative correlation between the ash fouling resistance and exhaust pressure obtained by site simulation test data processing, the comparison of accumulated cleaning effects between compressed air blowing and water washing in the same cleaning period etc. The SST results of CAB system show that: the water-saving quantity per year is 1.47 kg/m2; the accumulated average exhaust pressure of steam turbine is reduced by 1.7 kPa and the coal consumption has been reduced by 2.5 g/(kW·h) compared to water washing. That is, the CAB system can accomplish three goals at the same time: water-saving, energy-saving and emission reduction. © 2013 Chinese Society for Electrical Engineering.