某供热机组水汽氢电导率异常波动及超标原因分析

Analysis on abnormal fluctuation and over-standard of cation conductivity of water vapor in a heat-supply unit

联合使用在线化学仪表检验装置、痕量TOCi分析仪和离子色谱仪,从仪表测量准确性、有机物污染和无机离子污染等方面分析了某供热机组发生凝结水、给水氢电导率异常波动及超标的原因。根据计算得到的凝结水脱气氢电导率,判定凝结水是否因携带CO_(2)造成氢电导率偏高。分析认为,导致机组氢电导率异常波动及超标的主要原因是凝结水受到余热凝汽器疏水和定排扩容器炉水的污染,从而携带大量无机离子。另外,凝结水脱气氢电导率的计算值略低于氢电导率的测量值,表明凝结水携带少量CO_(2)。

Combined use of on-line chemical instrumentation,trace TOCi analyzer and ion chromatograph,the causes of abnormal fluctuation and over-standard of cation conductivity in condensate and feed water of a heat-supply unit were analyzed from the aspects of measuring accuracy,organic pollution and inorganic ion pollution.According to the calculated degassing cation conductivity from condensate,it was determined whether the high cation conductivity was caused by CO_(2) carried by condensate.It was concluded that the cation conductivity abnormal fluctuation and overstandard of the unit were caused by the contamination of condensate from the waste heat condenser and the boiler water from the fixed-discharge expanding vessel,thus carrying a large number of inorganic ions.In addition,the calculated value of degassing cation conductivity of condensate was slightly lower than the measured value of cation conductivity,indicating that the condensate carried a small amount of CO_(2).