600MW直接空冷机组凝结水回水系统改造对回热效率的影响

The Influence of Condensate Water Return System Reform on Thermal Recovery Efficiency of 600 MW Direct Air-Cooling Unit

针对内蒙古鄂温克发电厂的2台600MW的超临界燃煤直接空冷汽轮机机组存在的凝结水过冷度与溶氧量超标问题。提出在排汽装置导流板喉部位置加装凝结水雾化喷头和增加内置除氧器的方法降低凝结水过冷度和溶氧量,并采用等效焓降法对改进的机组进行了分析计算。结果表明,通过对机组的改进,凝结水过冷度与溶氧量均明显降低,凝结水温度升高,从而降低了机组的抽汽量、蒸汽消耗量和发电煤耗。

Aiming at the problems of condensate supercooling and dissolved oxygen exceeding the standard of two 600 MW direct air-cooled coal-fired steam turbines in Ewenke Power Plant,Inner Mongolia.The method of installing condensate atomizing nozzle and increasing built-in deaerator at the throat of the guide plate of the exhaust steam device is put forward to reduce the supercooling degree and dissolved oxygen content of condensate water.The improved unit is analyzed and calculated by equivalent enthalpy drop method.The results show that through the improvement of the unit,the supercooling degree and dissolved oxygen content of condensate water are obviously reduced,and the temperature of condensate water is increased,which reduces the steam extraction capacity,steam consumption and coal consumption of the unit.