秦二厂3、4号机停机初中和池废水来源分析及优化

Analysis and Optimization of Early Post-overhaul Origin of Wastewater Neutralization Tank of Units 3&4 in Qinshan Nuclear Power Company

由于技术规范对水质的要求,机组停机后一段时间内汽机二回路水排放均需先排放至废水中和池处理。秦二厂4号机408大修停机时发现废水中和池液位快速上涨,导致大量废水产生且有溢流风险。通过流程分析的方法,发现停机后凝汽器排水和循环水管坑集水井排水导致了废水中和池液位快速上涨。在对各来水量进行细化计算的基础上,提出了推迟行政隔离的实施、蒸汽发生器排污废液经除盐床处理后参数合格直接进行排放及对冷却水进行节流等优化方式,并在3号机309大修中得到实施验证,解决了废水中和池来水问题,减少了废水产生和人力损耗。这种流程分析的方法对解决机组生产上的弱项起到很好的作用,对解决类似问题有一定借鉴意义。

Due to the requirements of technological specifications for water quality,during a period of time after shutdown of steam turbines,secondary feedwater needs to be first discharged to wastewater neutralization tanks for treatment.It was found during the 408 overhaul of Unit 4 in Qinshan Nuclear Power Company a rapid increase of liquid level in the wastewater neutralization tank,generating a large amount of wastewater and posing a risk of overflow.This paper reports the causal identification through the method of process analysis observing the effects of the drainage of condenser and the drainage of circulating water pipe pit after shutdown of the steam turbines.Based on detailed calculations of each incoming water quantity,the paper proposes optimization measures,such as delaying the implementation of administrative isolation,directly discharging steam generator waste with acceptable quality after desalination bed treatment,and throttling cooling water.The proposed countermeasures were implemented and verified in the 309 overhaul of Unit 3,which helped to solve the problem of incoming water of wastewater neutralization tank and reduce wastewater generation and manpower loss.This process analysis method performs well in solving the weaknesses in unit service and has certain reference significance to similar problems.