低温省煤器与暖风器联合系统应用

Application of combined system of low pressure economizer and air heater

介绍了低温省煤器与暖风器联合系统的概况及设计特点与优势,该联合系统是利用低温省煤器来加热凝结水,低温省煤器出口一部分凝结水加热暖风器,将空气预热器入口风温提高至70℃,另一部分凝结水排挤汽轮机抽汽增加汽轮机做功能力,实现节能。同时,对某300MW机组分别采用传统低温省煤器和低温省煤器与暖风器联合系统的节能效果进行了计算比较。结果表明:联合系统相比于纯低温省煤器系统多节煤约0.97g/(kW·h),节煤量主要来源于替代原有暖风器的耗汽量而产生的收益;随负荷降低,系统节煤能力减弱。

The design features and advantages of the combined system of low pressure economizer and air beater （CSLPEAH） were introduced. This system uses low pressure economizer （LPE） to heat condensa- tion water and part of the condensed water at the LPE outlet to heat the air heater,which make the air tem- perature at the air preheater inlet be increased to 70 ~C. Other part of the condensed water crowd out the steam turbine extraction, which can improve the turbine work ability and reduce the coal consumption. Mo- reover,comparison of energy saving effect was carried out between the CSLPEAH and LPE system. The results show that,the energy conservation potential of the CSLPEAH is 0.97 g/（kW · h） higher than that of the LPE system,the main energy conservation potential comes from economizing the steam consumption of the original air heater. The energy conservation potential of the CSLPEAH is worse at lower load.