Thermodynamics analysis and optimization of Tail Heating Surfaces system in Utility Boiler
The temperature of the flue gas leaving the boiler typically ranges from 120°C to 140°C,about 10%to 30%of the thermal energy is wasted.Therefore,there exists huge energy-saving potentials by optimizing the tail heating surfaces system in the utility boiler.Currently,the conventional utilization of the flue gas waste energy is to heat a part of the condensed water by installing a low-temperature economizer(LTE)below the air-preheater,as a result of which,extra work can be obtained by saving the extracted steam.However,in this method,the energy-saving effect is not very obvious and the related exergy loss of the conventional tail heating surfaces system is huge.The objective of this paper is to conduct a thermodynamic analysis and optimization design of the tail heating surfaces system.In the optimization system,the air-preheater can be divided into three parts,which is high-temperature air-preheater,main air-preheater and low-temperature air preheater.The high-temperature air-preheater and the economizer are installed in the separated flue,the two-staged air-preheaters are arranged in the main flue,and the low-temperature economizer is installed between the two-staged air-preheaters.Based on the data from a typical 1000MW power station,it is indicated that the temperature of the hot air can be increased by nearly 20 °C.Besides,the low-temperature economizer can save part of the extracted steam from the #5 regenerative heater,which leads to heat rate reduction of about 108kJ/(kW·h).Simultaneously,the exergy loss is also reduced from 47.1MW in conventional tail heating surfaces system to 36.5MW in the optimization system.
Tail Heating Surface Thermodynamic Analysis Optimizing Exergy Loss Utility Boiler
Gang Xu Cheng Xu Yongping Yang Yaxiong Fang Yuanyuan Li
North China Electric Power University,Beijing,China
国际会议
桂林
英文
1-10
2013-07-16（万方平台首次上网日期，不代表论文的发表时间）