等效排气筒有效高度计算方法的比选及其应用于大气污染预测的可行性

目前，等效排气筒多用于大气污染物总量控制，其预测精度和范围的不明晰限制了其在污染物运移扩散领域的进一步应用。基于《大气污染物综合排放标准》，依据所预测的范围和浓度精度对8种典型等效计算方法进行了比选，并验证了将等效排气筒用于不同工况下污染物运移扩散预测的可行性。改进的有效高度等效算法 (源强加权算术平均法) 综合考虑了不同高度和源强参数特征，以2个排放同种污染物的相邻排气筒为例，所计算的高斯模式下等效后下风向污染物浓度场总体分布趋势与等效前叠加计算结果一致，且预测精度优于《大气污染物综合排放标准》中提出的均方根平均法和其他等效算法。对不同风速条件下 (1.5~4.5 m·s⁻¹) 等效前后下风向污染物浓度场分布计算比较，发现即使风速改变仍可保证较高的最大落地浓度预测精度 (−6.87%~−2.21%)，特别是风速较大时其预测精度更高 (达到−2.21%) 。这验证了该方法的有效性和稳定性。本研究探讨的源强加权算术平均值算法，进一步提升了等效排气筒相关参数计算的合理性，并拓展了其在大气预测评价中的应用。

Comparison of methods for calculating the effective height of equivalent exhaust tubes and their feasibility in predictive applications

Equivalent exhaust tubes are currently used mainly for total air pollutant control, and the lack of clarity in prediction accuracy and scope limits its further application in the field of pollutant transport and dispersion. Based on the Integrated emission standard of air pollutants, this study compared and selected eight typical calculation methods according to the predicted scope and concentration accuracy, and the feasibility of using equivalent exhaust tubes for the prediction of pollutant transport dispersion under different working conditions was verified. The effective height equivalence algorithm (source intensity weighted arithmetic averaging method) modified in this paper was used to integrate the different height and source intensity parameter characteristics. Taking two adjacent exhaust tubes emitting the same pollutant as an example, the overall distribution trend of the calculated downwind pollutant concentration field under the Gauss model after equivalence was consistent with the results before equivalence. In addition, the prediction accuracy of this method was better than that of the root mean square averaging method proposed in the Integrated emission standard of air pollutants and other equivalent algorithms. The calculation and comparison of pollutant concentration field distribution in the downwind direction before and after equivalence under different wind speed conditions (1.5~4.5 m·s−1) showed that even if the wind speed changed, it could still ensure a high prediction accuracy of the maximum fallout concentration (−6.87%~−2.21%). Especially, the higher prediction accuracy (−2.21%) at higher wind seeds showed the effectiveness and stability of this method. The use of the source intensity weighted arithmetic averaging method will further improve the rationality of the calculation of the equivalent exhaust-related parameters and expand their application in air prediction and evaluation.