高原山区城市重气泄漏扩散的风洞试验研究  

Wind-tunnel experimental research on the dense gas plume dispersion in plateau cities

作　　者：张朝能[1,2] 宁平[1] 马彩霞[1,3] 沈武艳[1] 

机构地区：[1]昆明理工大学环境科学与工程学院,昆明650093 [2]昆明市环境科学研究院环境咨询研究中心,昆明650032 [3]云南省环保产业科技开发中心,昆明650032

出　　处：《安全与环境学报》2009年第1期120-123,共4页Journal of Safety and Environment

基　　金：教育部春晖计划项目(2003009)

摘　　要：进行重气泄漏扩散环境风洞试验,研究高原山区城市中重气泄漏扩散规律。结果表明,高原山区城市重气泄漏扩散存在1个危险风速,该风速下环境中重气浓度达到最大值,同时黏滞系数也达到最大值。通过多项式拟合可求出危险风速。当地年平均风速条件下,重气浓度随下风距离增加而减小,而在排放源下风向500 m外,随着距离的增加,重气浓度的变化趋缓;重气浓度在横风向上呈偏态分布;在垂直方向上随着高度的增加而减小,而高度超过20 m后重气浓度随高度的变化较小。This article is to report the results of our wind-tunnel experimental research on the dense gas plume dispersion in highland cities. The model we have adopted is made in a ratio of 1 ： 1 000 according to the terrain and the layout of the city buildings. The tracer we have adopted is Freon 12, which measures by gas chromatography with the electron capture detector, with the plume created by a small circular source on a ground level and the monitoring point on the ground floor distributed as the fan shape, which keeps a division of seven lengths in a horizontal direction, i.e. 250 m, 500 m, 750 m, 1 000 m, 1 250 m, 1 500 m and 1 750 m, as well as seven heights in a vertical direction, i.e. 1 m, 20 m, 30 m, 50 m, 80 m, 120 m and 180 m.The flowing range of the wind tunnel is similar to that by adjusting the layout of the coarse component and the distribution of wind rail. By nature, the characteristic features of the dense gas plume dispersion in plateau cities found in accordance with our wind tunnel experiments indicate that there exists a potentially dangerous wind velocity whose concentration of dense gas can be taken as maximal, with its viscous coefficient also reaching its maximum, which can be calculated with fitting of polynomial. Thus, the result of our experiment also shows that the concentration of dense gas can be reduced quickly with the increase of the downwind distance, but the variation of concentration with the downwind distance can be slowed down after the downwind 500 m of leakage point at the annual average wind velocity. In addition, the variation of concentration with the transverse distance is skew distribution. The concentration of dense gas is likely to get reduced with the increase of height at the vertical direction, but the variation of concentration with the height can be slowed down with the height over 20 m.

关 键 词：安全工程 重气 环境风洞 黏滞系数 危险风速 

分 类 号：X928.5[环境科学与工程—安全科学]