超临界350 MW机组锅炉高能水回收技术经济性分析

Technical and economic analysis of boiler high energy water recovery for supercritical 350 MW unit

随着风电、水电和光电等清洁能源装机容量的迅猛发展,国内的用电结构发生较大变化,大型火电机组深度调峰运行已成为常态。机组深度调峰至较低负荷时,直流锅炉由干态转为湿态运行,由锅炉汽水分离器分离出的水直接进入凝汽器或通过排污系统排出,造成了大量的热量和质量损失,导致机组运行经济性大幅下降。本文研究分析了直流锅炉湿态运行的特点,提出2种高能水热-质回收技术方案:通过闪蒸罐回收至除氧器和通过升压泵回收至给水管道,通过Ebsilon软件计算并对比了高能热-质回收前、后的运行能耗,结果表明回收后锅炉湿态运行时机组能耗显著下降,经济性大幅提高。

With the rapid development of installed capacity of clean energy such as wind power,hydropower and photo electricity,the domestic electricity consumption structure has undergone great changes.Deep peak shaving to low-load operation of large thermal power units has become normal.When the unit is deeply adjusted to lower load,the once-through boiler will change from dry to wet operation.Usually,the water separated by the boiler steam-water separator goes directly to the condenser or to the sewage system,which will cause lots of heat and mass loss.Thus,the operating economy of the unit will reduce significantly.In this paper,the characteristics of oncethrough boiler under wet operation have been researched and analyzed.Two high-energy heat-mass recovery technical solutions:through the flash tank to the deaerator and through the booster pump to the water supply pipeline have been proposed.Furthermore,the operating energy consumption before and after high-energy heat-mass recovery has been calculated and compared by Ebsilon software.The results show that,after recovery the energy consumption of the unit will reduce significantly and the economy will improve greatly.