烟塔合一排烟对近距离环境影响的预测研究

Prediction Study on the Effect of Flue Gas Discharge from Natural Draft Cooling Tower on Nearby Atmosphere Environment

针对烟塔合一排烟对近距离环境影响的预测进行研究,分别运用物理风洞实验、数值风洞模拟和德国Austal 2000模式3种方式模拟冷却塔下风向空腔区范围,以及空腔区对污染物近距离落地浓度分布的影响,并分析3种不同模拟方法在烟塔合一排烟技术近距离环境影响预测中的差异。结果表明:空腔区的长度大致在冷却塔塔底边缘2.2倍塔高处,高度大致在1.2倍塔高处;近距离范围内污染物落地浓度随距离的变化受空腔区影响巨大,具体表现为落地浓度在空腔区内呈增大趋势,远离空腔区的范围则大致稳定或存在小幅波动;二维数值风洞更适用于空腔区范围的拟合,物理风洞更适用于近距离污染物落地浓度分布的模拟。

Environmental impacts on the nearby atmosphere environment of cooling tower have been analyzed in this study.The physical wind tunnel experiment,numerical wind tunnel simulation and German Austal 2000 standard model were used to study the range of the cavity area and the influence of the cavity area on the ground concentration distribution of pollutants.It has been found that the length of cavity area is approximately 2.2 times the height of cooling tower,while the height of cavity area is approximately 1.2 times.The diffusion and transporting behaviors of flue gas pollutants from coal-fired power plant are greatly affected by the cavity area in nearby atmosphere environment.The ground concentration of pollutants is increased progressively in the cavity area,and kept stable or slightly fluctuating away from cavity area.In addition,the comparison of prediction results obtained from three methods showed that two-dimensional numerical wind tunnel was more suitable for the fitting of cavity area,while physical wind tunnel was optimizing better choice of predicting the ground concentration distribution of pollutants from natural draft cooling tower in nearby atmosphere environment.