适应于空冷机组的高效余热回收利用系统

High-efficient Waste Heat Recovery System of Air-cooling Unit

为了发掘空冷机组的余热利用潜能,基于空冷机组的运行特点提出了一种高效的余热回收利用系统,即引用空冷岛的热空气作为锅炉燃烧用风,提高了空气预热器入口风温,减少空气预热器的换热量。通过加设旁路烟道系统实现尾部烟气热量的重新分配和回收利用,最终达到降低机组煤耗的效果。结合某典型600 MW空冷机组数据进行分析。计算结果表明:新系统可降低供电煤耗1.91g/(kW·h),按机组年运行5 000h、标煤750元/吨计年节煤收益可达429万元,经济效益显著。

In order to explore the waste heat potential in the air-cooling power generation unit,a high-efficient waste heat recovery system is proposed based on the operating characteristics of the air-cooling unit.In the proposed system,the hot air from the cooling tower is used as the combustion air,which increases the inlet air temperature of the air preheater,reduces the heat exchanger amount and reduces the related coal consumption rate by adding a new bypass flue system to realize the rearrangement and recovery of the waste flue gas heat.This paper conducts a data analysis of a typical 600 MW air-cooling unit and the results show that the new system can reduce the coal consumption rate by 1.91g/（kW·h）.Besides,the annual economic income by coal saving can reach 4.29 million when the operating hours and the coal price is set as 5 000 hours and 750RMB/ton respectively,whose economic benefits is obvious.