地下车库颗粒受限扩散下的凝并特性  

Characteristic of particle coagulation under constrained dispersion conditions in underground parking lot

作　　者：赵宇[1] 加藤信介[2] 赵加宁[1] 

机构地区：[1]哈尔滨工业大学市政环境工程学院,哈尔滨150090 [2]东京大学生产技术研究所

出　　处：《哈尔滨工业大学学报》2016年第3期184-188,共5页Journal of Harbin Institute of Technology

摘　　要：为研究车辆排放颗粒在地下车库内凝并率的分布规律及其对颗粒受限扩散的影响程度.根据颗粒物扩散和凝并理论,采用Realizable k-ε模型模拟空气流场分布特性,并结合数值模拟中的场函数方法将颗粒凝并和扩散过程相结合,分析地下车库不同数量车辆在受限扩散条件下颗粒半衰时间的变化和粒径变化.结果表明:在排气管附近,颗粒半衰时间最短,凝并作用最强.在沿高度方向2 m以下的区域内,当启动车辆数不多于2台时,颗粒半衰时间随高度线性下降,当启动车辆数不少于4台时,半衰时间随高度呈对数下降.凝并作用对中间段和大粒径段粒子数浓度的变化影响更大,颗粒呈现出由小变大的粒径变化趋势.启动车辆数越多,凝并导致的粒径分布不均匀性越明显.In order to analyze the characteristic of particle coagulation from vehicle exhaust under constrained dispersion conditions and the effect of coagulation on dispersion in an underground parking lot, the study numerically simulated the particle concentration fields under steady-state constrained dispersion conditions using Realizable k-ε model and field functions based on the theories of particle dispersion and coagulation,and then analyzed the characteristics of particle decrease half-time due to coagulation and variation of particle size distribution. The simulation results demonstrated that particle decrease half-time was shortest near the tailpipe exhaust. In the area lower than 2 m in vertical direction in an underground parking lot,when idling cars were not more than 2,half-time decreased linearly with the increase of distance above the ground; when idling cars were not less than 4,half-time decreased logarithmically with the increase of distance above the ground. The effect of coagulation on variation of particle number concentration in the middle and large size categories was more obvious than that in the small size categories. Particle size changed from small to large due to particle coagulation. The uneven distribution of particle size was more obvious as the number of idling cars increased.

关 键 词：地下车库 受限扩散 粒子数浓度 颗粒凝并 自然通风 

分 类 号：TU834.6[建筑科学—供热、供燃气、通风及空调工程]