提出了一种利用汽包锅炉排污系统余热的有机朗肯循环发电系统,有机工质回收扩容器疏水的热量,并通过气轮机发电。建立了系统的热力性能分析模型,并对R227ea、RC318、R236ea、R245fa、R245ca、R123和R113等7种工质的热力性能进行了优化。结果表明,临界温度高的工质,其o2循环的最佳主气温度(蒸发温度)反而低;亚临界循环采用干流体时,过热不利于余热的利用;超临界循环可以改善热源与工质间的温度匹配,有利于增大系统输出功,但是其运行压力高、大比热区的传热恶化等问题是实际运行和设计需要考虑的因素;R236ea的热力性能优于其余6种工质。
China still depends on coal-fired power plants which account for 78.6% of the total electricity generation in China. Pollution caused by coal utilization is a serious problem. Although the standard coal consumption rate has decreased to 326 g/(kW.h), energy conservation and emission reductions are needed in coal-fired power plants.