水冷式换热器腐蚀动态模拟及预测研究

Dynamic Simulation and Prediction of Corrosion Rate in Water-cooled Heat Exchangers

为研究水冷式换热器腐蚀速率与影响因素的定量关联及机理,开发了腐蚀速率三电极传感器,并基于自制的腐蚀速率动态模拟实验台,以典型水样作为实验介质,在一定工况条件(水温30℃,流速0.4m/s)下,动态模拟了管式碳钢换热器腐蚀过程,通过在线或离线检测,为腐蚀速率预测建模获取了不同水质的腐蚀速率、Cl-、pH、溶解氧、电导率以及ORP等参数数据,并对腐蚀速率和各水质参数变化曲线进行了分析。基于获取的实验数据,利用支持向量机(SVM)算法,建立了腐蚀速率预测模型,并进行了误差分析。结果表明:腐蚀速率预测误差为5.91%,与实际测量腐蚀速率能够较好吻合,该方法具有较高的预测精度,可为水冷式换热器防腐对策选取和设备维护提供技术参考。

A three-electrode sensor for the corrosion rate was developed to investigate both relationship between influence factors and corrosion rate in a water-cooled heat exchanger and the corrosion mechanism; taking typical water sample as the medium and under the working condition of 30℃ water temperature and 0.4 m/s flow velocity,the corrosion process of the heat exchanger made of the tubular carbon steel was simulated dynamically; and basing on the on-line or off-line monitoring,the corrosion rate,Cl-,pH,DO,conductivity,and ORP in different water were obtained to benefit the establishment of prediction model and the analysis of corrosion rate and water quality parameter curves.By using the experimental data and the SVM algorithm,the error of forecast model was analyzed to show that the 5.91％ prediction error coincides with the corrosion rate measured.This method can benefit the selection of water-cooled heat exchangers and can provide the equipment maintenance with technical reference because of the high prediction accuracy.