引射式加热器替代低压回热系统等效焓降分析

火电机组低压回热系统中的面式加热器普遍存在较大损。应用等效焓降方法,深入分析采用引射式加热器替代面式低压加热器下机组热经济性的变化，并得到各个变化因素的数学计算式。在此基础上，对N600-165/535/535型机组低压回热系统进行实例计算，并与常规热平衡法计算进行了比较，结果表明：引射式加热器替代面式低压加热器，可以有效减小损，替代全部四级面式低压加热器，可使机组经济性提升最大，达0.263%；文中分析推导得出的计算表达式可用于机组热经济性分析计算。

The equivalent enthalpy drop theory calculation of the ejector heaters applied for low-pressure feed water heater system of thermal power unit

There is much exergy loss in low-pressure feed water heater system of the thermal unit. The thermo-economic characters by the equivalent enthalpy drop method while the low-pressure heater was replaced with the ejector heater. At the same time, the thermo-economic characters formulas for the different factors were also gotten. Based on these results, the thermo-economic changing features were analyzed for the low pressure heaters replaced with the ejector heaters of the N600-165/535/535 units, and the results were compared with the normal heat balance method. The results show that the ejector heaters can reduce the exergy loss efficiently, and the thermo-economic effects is the best for replacing the all low-pressure heaters with the ejector heaters, and its efficiency can be increased by 0.263%. The given equations of this paper can be used for analyzing the thermal economic effects.