300 MW热电机组锅炉水质异常分析及处理

摘要

The conductivity and pH value of boiler water in No.1 unit of Midong Thermal Power Plant were over standard.So the water wall tubes suffered the risk of alkaline corrosion and boiler water concentrate corrosion.Detection finds a larger number of free sodium hydroxide appears in the boiler water.This is because the heat-supply network drain which is used as the feed water supplement water was polluted by leakage of circulating water of district heating system heater. The check valve between the steam separated from continuous blow-down flash vessel and the de-aerator had some defects,leading to invalid blow down,so the boiler water were over concentrat-ed,a larger number of free sodium hydroxide appeared in the boiler water,resulting in boiler wa-ter abnormality eventually.Finally,after improving continuous blow down,the boiler water turned back to normal.%新疆米东热电厂1号机组锅炉炉水电导率和 pH 值较高,超出正常范围,对水冷壁管存在腐蚀的风险。检测发现炉水中出现了大量游离NaOH,分析发现其由作为给水补水的热网疏水受热网循环水的污染所致。由于连续排污扩容器的分离蒸汽至除氧器的逆止阀存在缺陷,造成锅炉未真正有效排污,炉水长期处于过度浓缩状态,最终产生大量游离NaOH,对锅炉加强排污后,炉水水质恢复正常。