火电机组再热段抽汽供热方式的热经济性研究

Research on Thermal Economy of Extraction Steam Heating Mode Through Reheat Section in Thermal Power Units

针对再热段抽汽供热方式的特点,提出供热工况的热经济性计算方法,并且以国产火电机组为例,基于不同负荷工况和不同机组容量对冷段抽汽和热段抽汽供热方式的热经济性进行对比分析。计算结果表明:相同供汽量下的机组热经济性随着负荷的降低而增加,冷段抽汽相比于热段抽汽的节能优势也随之降低;相比于大容量机组,小容量机组在供热工况下的热经济性更优。

According to the characteristics of reheat section extraction steam heating mode,a method of thermal economy calculation was presented.Taking domestic thermal power units as the research examples,comparisons and analyses were conducted on the thermal economy of extraction steam heating mode through cold reheat section and hot reheat section based on different unit loads and different unit capacities.Calculation results show that,under the same heating steam flow rate,the thermal economy of the unit increases with the decrease of the unit load,and the energy saving advantage of the extraction steam heating mode through cold reheat section dwindles compared with through hot reheat section.Additionally,the thermal economy of the small capacity unit is better than that of the large capacity unit under heating condition.