竖壁贴附通风供热模式水平贴附射程及热环境特性CFD模拟

CFD simulation of horizontal attachment distance and thermal environment characteristics of rooms with vertical wall attached ventilation in heating mode

为解决混合通风冬季供热时热风易停滞在房间顶部造成无效能源消耗的问题,采用CFD数值模拟方法研究了竖壁贴附通风供热模式下水平贴附射程达到设计要求的条件,并在此基础上分析了竖壁贴附通风用于供热时的室内热环境特性。在6.19 m(长)×3.44 m(宽)×2.80 m(高)的房间进行了研究,结果表明:冬季供热工况下,在舒适性空调送风参数范围内,竖壁贴附射流轨迹及射程由惯性力主导,热浮升力影响次之,水平贴附射程大于房间长度的80%,即Ar<0.0015时认为水平贴附射程达到送风要求;当送风速度大于4.14 m/s时,房间中轴面附近距地面0.5 m高度以下工作区局部可能造成人员脚踝处的吹风感,人员应远离房间中轴面上距离送风口较近的位置;由于热气流首先送入工作区,热风沿高度方向不断补偿房间围护结构的失热量,在竖直方向上并没有明显的热分层现象,热量能被有效利用。

To solve the problem that the hot air tends to distribute at the top of the room causing inefficient energy consumption when heating with mixed ventilation mode in winter,studies the conditions of horizontal attachment distance meeting the design requirements under vertical wall attached ventilation heating mode by CFD numerical simulation method,and on this basis,analyses the indoor thermal environment characteristics under this heating mode.The research results in a 6.19 m(length)×3.44 m(width)×2.80 m(height)room show that the jet trajectory and range of vertical wall attached ventilation are dominated by inertial force,followed by thermal buoyancy within the air supply parameters of comfort air conditioning under winter heating conditions.If the horizontal attachment distance is greater than 80%of the room length,which means Ar<0.0015,it is considered that the horizontal attachment distance reaches the air supply requirements.When the air supply velocity is greater than 4.14 m/s,a blowing sense at the personnel’s ankles may occur in the occupied zone below 0.5 m from the ground near the central shaft surface of the room,and the personnel should be arranged away from the position on the central shaft surface of the room that is closer to the air supply outlet.The hot air flows through the occupied zone firstly,and it can continuously compensate the heat loss of the enclosure structure of the room along the height direction.There is no obvious thermal stratification in the vertical direction,making the heat being utilized effectively.