速率系数可变模型的建立及其性能研究

Estabishment and performance of variable rate coefficient model

摘要:

针对以往氯衰减模型的局限性,提出一种旨在提高预测结果准确性和实用性的新的氯衰减模型——速率系数可变模型(Variable Rate Coefficient,VRC),模型的建立基于双分子二级反应动力学速率方程,共包含4个参数(X0,κ0,kmin和α).采用6个水源的实验数据对VRC模型、一级模型以及由Boccelli等人建立的二级模型进行校核和比较分析.结果表明:VRC模型对所有数据集的拟合情况均明显优于另外两个模型,可以更为准确地预测氯的衰减情况.为保证模型预测结果的精度,在校核VRC模型时,除了最好使用至少1组初始氯质量浓度较高的数据集以保证模型的稳定性之外,还应调整输入VRC模型中的初始氯质量浓度以减小模型预测值和实测值之间的差距.

Abstract:

According to limitations of previous chlorine decay models,a new model named as variable rate coefficient model (VRC) was built to improve the accuracy and reliability of chlorine decay model.The VRC model includes 4 parameters (X0,κ0,kmin and α) and is based on the kinetic rate equations from concurrent bimolecular second-order reactions.In this study,6 data sets from different water sources were used.Three models including VRC model,the first-order model and a second-order reactive species model built by Boccelli et al.were calibrated and compared.Results show that compared with other two models,the simulated values of VRC model agree very well with the experimental data.The VRC model can accurately predict chlorine decay.In order to ensure the accuracy of VRC model,it is preferable to calibrate the VRC model using data sets with a chlorine concentration that is at least as high as or even higher than that used during normal operating conditions.Furthermore,the chlorine concentrations used as model input should be adjusted to minimize the differences between model predictions and the observed chlorine concentration.