冷凝释放热对周围环境及自然通风的影响研究

Effect of Condensation Heat Release on Ambient Environment and Natural Ventilation

本文以分体式空调的室外机为对象,采用CFD方法,使用FLUENT软件模拟了不同的环境风速条件下,不同热释放率的室外机周围的速度场、温度场,分析室外机释放的冷凝热对建筑周围热环境的影响。还模拟了室外机置于建筑迎风面、背风面和无室外机散热影响情况下某大开口单体建筑的自然通风情况,分析通风过程中的速度、温度以及压力分布情况,研究冷凝热释放对自然通风的影响。室外机组的尺寸为900mm×900mm×300mm,距建筑外墙的距离为0.2m,距地面0.5m。由模拟结果可以看出由于热浮力的作用,热气流有明显的上升趋势,并逐渐向外墙面贴附,且影响范围很大。热空气的上升运动不仅与室外机的热释放率有关,而且与室外环境的风速也有关系。本文首次采用热污染边界层的概念来定义室外机冷凝热释放的影响范围,并对室外机的安装布置提出合理化建议。

This paper simulated the temperature and flow field around the outdoor unit at different wind speeds and different heat release rate by using FLUENT software,and analyzed the effect of outdoor unit heat release on thermal environment around the building.The different air flow processes during outdoor unit placed on different position was also simulated.The flow speed,temperature and pressure distribution during different ventilation processes was analyzed,and finally the effect of the condensing heat release on the natural ventilation was researched.Size of the outdoor unit is 900mm×900mm×300mm,0.2m distance from construction wall,0.5m distance form the ground.From simulation results it＇s found out that the hot air flow upwards and gradually attached to the wall because of thermal buoyancy.The plume configuration is related to the heat release efficiency of the condenser as well as the wind speed of environment.A large range is affected by the hot air drained from the outdoor unit.The concept of heat pollution boundary layer is first presented to evaluate the range of heat air drained from the condenser.The findings of this paper give several rationalization proposals to the placement of outdoor units.