某9F级燃气-蒸汽联合循环余热锅炉炉水水质异常分析

Analysis of Abnormal Water Quality in a Heat Recovery Steam Generator of a 9F Class Gas-Steam Combined Cycle Unit

某燃气-蒸汽联合循环机组余热锅炉炉水pH值和电导率出现异常偏高问题,蒸发器管存在腐蚀风险。通过检测水汽氢电导率、痕量离子及硬度,结合热力系统水汽流程综合分析发现热网加热器发生了泄漏,热网循环水漏入机组水汽系统后,热网补水中加入的氢氧化钠,叠加碳酸盐在高温下水解生成的氢氧根,经炉水浓缩作用致使炉水水质异常。根据分析结论提出了消缺措施,使该问题得到及时顺利解决。

The pH value and conductivity of the boiler water in a heat recovery steam generator of gas-steam combined cycle unit are abnormally high,causing a risk of corrosion in the evaporator tube.By detecting the hydrogen conductivity,trace ions and hardness of water vapor system combined with the comprehensive analysis of the water and steam system,it is considered that the heater of heating network has leaked.After the hot network circulating water leaked into the water vapor system of the unit,the sodium hydroxide added in the supplementary water of the heating network leaked into to the water vapor system.The superimposed carbonate is hydrolyzed at high temperature to form hydroxide,and the water quality of the boiler is abnormal due to the concentration of the boiler water.According to the conclusion of the analysis,the elimination measures were put forward,so that the problem can be solved in time and smoothly.