供热机组水汽指标异常分析及对策

Analysis and Countermeasures of Abnormal Water Vapor Indexes of Heating Unit

通过对某330MW亚临界自然循环汽包炉在供热期间异常超标的典型水汽指标进行梳理,排查分析了造成给水溶氧、水汽氢电导超标的主要原因。通过采取延长供热疏水排放管长度至水箱控制液面以下以减少回收水中氧气和二氧化碳的携带量、检修时对供热换热器管束全面查漏堵漏、加强在线仪表校验维护、合理调整给水和炉水加药量、加大炉水连续排污和定期排污,及时调整除氧器排气门开度及做好供热系统停备用期间的保护等一系列措施后,有效提升了给水溶氧、水汽氢电导指标的合格率,降低了水汽热力设备腐蚀、结垢的风险,为同类型机组故障问题的解决提供了参考。

By analyzing the typical water vapor indicators of a 330 MW subcritical natural circulation steam drum boiler that abnormally exceeded the standard during the heating period,the main causes of feedwater dissolved oxygen and water vapor hydrogen conductivity exceeding the standard were explained.A series of measures have been taken,such as extending the length of the hydrophobic discharge pipe below the control level of the water tank to reduce the carrying amount of oxygen and carbon dioxide in the recovered water,comprehensive leak detection and plugging of the heat exchanger bundle during maintenance,strengthening the online instrument calibration and maintenance,reasonably adjusting the dosage amount of feed water and boiler water,increasing the continuous and regular discharge of the boiler,adjusting the opening of the exhaust valve of the deaerator in time,and protecting the heating system during the standby period etc.The qualification rate of feedwater dissolved oxygen and water vapor hydrogen conductivity indexes has been effectively improved,and the risk of corrosion and scaling of water vapor thermal equipment has been reduced,which provides a reference for solving the fault problems of the same type of units.