下送风空调系统送风口气流方向对室内气流分布的影响分析

Study on the Influence of Different Inlet Wind Directions on Airflow Pattern for Under Floor Air Distribution System

一个设计良好的下送风空调系统具有改善热舒适性、通风效率和室内空气品质,减少能耗、建筑周期花费和层高等优点。本文通过对某一下送风空调系统在送风方向分别与地面之间的夹角(记为α)为0°、45°和90°的条件下,进行了数值模拟计算,分析了不同送风方向时室内气流分布的不同。研究结果表明:α为0°和45°时的室内气流分布类似,室内最大速度都贴近地面,且形成的涡位于室内高度1/2以下,45°时室内产生更多的涡流;α为90°时靠近地面处流速很小,形成的涡位于室内高度1/2以上。对d为0°的情况进行了水模型试验,试验现象表明近地面处速度的分布与模拟计算结果基本吻合。研究结果对预测和控制下送风空调系统的扬尘有理论意义。

A well-designed under floor air distribution （UFAD） system can provide such benefits as improving thermal comfort,ventilation ef- ficiency and indoor air quality, and meanwhile reduce energy consumption, operation costs and floor-to-floor height in new constructions. This paper fouses on the association betwenn different air supply angles and airflow distribution for UFAD system. The air supply angle α is the angle between inlet airflow and ground. The airflow distribution of an office with a UFAD system is simulated respectively by CFD when α is 0° , 45° and 90°. Simulation results show that when α is 0° and 45° ,the indoor air distributions are similar,the maximal velocity happens close to the floor,vortices are all below half of the storey beight,and more vortices are formed when α is 45°. when α is 90° ,the velocities close to the floor are small, and vortices happen above half of the storey height. Similiarity experiment is conducted in water when α is 0°, experiment results indicate that velocity distribution agree with simulation results, Which serves to predict and control the dust suspension.