冷渣器冷却水回水接入点分析及改进方案

ANALYSIS ABOUT JOINTING POINT OF RETURNED COOLING WATER FROM THE SLAG COOLER AND IMPROVEMENT SCHEME THEREOF

针对蒙西发电厂2×300 MW机组的冷渣器冷却水回水接入点不当,导致机组整体循环效率降低,影响机组运行经济性的问题进行了分析,提出了优化改进方案。与原接入点相比,采用将冷渣器冷却水回水接入7号低压加热器(低加)入口,且所有凝结水串联通过冷渣器和7号低加的方案,可使机组负荷在292 MW时供电煤耗率下降1.25 g/(kW.h),在202 MW时供电煤耗率下降1.67 g/(kW.h);采用将冷渣器冷却水回水接入6号低加入口,且凝结水并联通过冷渣器和7号低加的方案,可使机组负荷在292 MW时供电煤耗率下降0.83 g/(kW.h),在202 MW时供电煤耗率下降1.22 g/(kW.h)。

Directiong against improper jointing point of returned cooling water from slag cooler of 2 × 300 MW units in Mengxi Power Plant, the decrease of integral cycle efficiency and its influence upon economic efficiency in operation of the units have been analysed, and an optimized improvement scheme being put forward on the basis of data obtained from results of analysis. Compared with the original units,a scheme,in which the returened cooling water from slag cooler is jointed into the inlet of low - pressure heater no. 7,and all condensate being passed through the salg cooler and low - pressure heater no. 7 in series has been adopted,the net coal consumption rate can be lowered by 1.25 g/（kw · h） and 1.67 g/（kw · h） under load of the unit being 292 MW and 202 MW respectively. In the event of returned cooling water being jointed into the inlet of low - pressure heater no. 6, and all condensate being passed through the slag cooler and low - pressure heater no. 7, the net coal consumption rate can be lowered by 0. 83 g/（kw · h） and 1.22 g/（kw·h） under load of the unit being 292 MW and 202 MW respectively.