1000MW超超临界二次再热机组外置式蒸汽冷却器布置方式研究  

Arrangement of Outer Steam Coolers for a 1 000 MW Double Reheat Ultra-supercritical Unit

作　　者：付文锋[1] 石宇[1] 李嘉华[1] 杨勇平[1] 

机构地区：[1]华北电力大学电站设备状态监测与控制教育部重点实验室,河北保定071003

出　　处：《动力工程学报》2017年第6期489-494,共6页Journal of Chinese Society of Power Engineering

基　　金：国家自然科学基金资助项目(51606066)

摘　　要：以某1 000 MW超超临界二次再热机组为例,利用单耗分析方法,计算了单级串联、双级串联、双级并联3种外置式蒸汽冷却器的布置方式对机组能耗的影响,得到了外置式蒸汽冷却器的最佳布置方式和热力系统中各设备单耗的变化规律,并分析了最佳布置方式下机组单耗随负荷的变化趋势.结果表明:外置式蒸汽冷却器可以提高给水温度,减少锅炉的不可逆损失,这是机组单耗降低的主要原因;采用单级时,布置于第2级的效果最佳,可使机组单耗降低0.632g/(kW·h);采用双级时,布置于第2、第4级的串联方式效果最佳,可使机组单耗降低1.122g/(kW·h);随着负荷的降低,双级串联外置式蒸汽冷却器的降耗效应略有下降.Taking the 1 000 MW double reheat ultra-supercritical unit as an example, based on analysis of the specific fuel consumption, the effects of following arrangement modes of outer steam coolers on the energy consumption of unit were studied, such as the single series connection, double series connection and double parallel connection, etc. , and subsequently the optimum arrangement mode of outer steam coolers was obtained, in which case the variation law of specific fuel consumption was analyzed for each part of the thermal system and for the whole unit. Results show that by adopting the outer steam coolers, the feedwa- ter temperature is raised, the irreversible loss of boiler is reduced, thus lowering the specific energy consumption of unit. In the single connection mode, the specific fuel consumption can be reduced by 0. 632 g/ （kW · h） at most when the outer steam cooler is arranged at No. 2 high-pressure heater; whereas in the double connection mode, the specific fuel consumption can be reduced by 1. 122 g/（kW · h） at most when the coolers are arranged in series at No. 2 and No. 4 high-pressure heater. With the reduction of unit load, the energy-saving effect will have slight decrease if double outer steam coolers are arranged in series connection.

关 键 词：二次再热 外置式蒸汽冷却器 布置方式 单耗分析方法 

分 类 号：TK284.1[动力工程及工程热物理—动力机械及工程]