火电机组减温水系统热经济性计算

Thermal Economy Calculation of Desuperheating Water System for the Coal-fired Power Unit

以火电机组热力系统的汽水分布方程、汽轮机输出内部功率方程、锅炉工质吸热量方程为基础,推导了过热减温水和再热减温水不同来源时,机组减温水系统热经济性整体计算的数学模型。利用该模型,以通用型300 MW火电机组为例,进行算例分析,结果表明当过热减温水来自给水泵出口,再热减温水来自给水泵中间抽头时,再热减温水比过热减温水对机组热经济性影响更大。另外该数学模型具有很好的通用性,适用于不同类型的火电机组,为指导热力系统设计、运行及合理改造提供了技术依据。

Based on the steam-water distribution equation,steam turbine output internal power equation,and boiler medium heat equation of thermodynamic system,the mathematical model for the thermal economy entire calculation of desuperheating water system is obtained when the desuperheating water for the boiler′s superheater and reheater have separate sources.With this model,the 300MW unit is calculated and the results indicate that when the desuperheating water for the boiler′s superheater comes from feed water pump outlet and the desuperheating water for the boiler′s reheater comes from center tap to the feed water pump,the latter has more effect on thermal economy.Moreover,this model can be put in wide range of usage since it is suitable for different types of coal-fired power plant and provides technical basis for guiding thermodynamic system design,operation and redevelopment.