地板送风室内温度不均匀分布特性的实验研究

Experimental Research on Indoor Air Temperature Distributions with Underfloor Air Supply

通过变化送风参数和室内热源,对6种典型工况的实验结果进行了分析,得到了地板送风室内温度分布的一些特性.针对地板送风室内温度分布的不均匀性,采用工作区垂直温差和0.1 m高度处的空气温度与送风温度之差来表征工作区温度分布.实验结果表明:单位送风量的室内热源散热越大,不仅室内垂直温度梯度较大,而且工作区垂直温差增加的幅度比送回风温差增加的幅度更大,当室内冷负荷从324 W逐渐增大到468 W时,工作区垂直温差与其送回风温差之比从0.468增大到0.573;室内工作区垂直温度分布的形状与室内热源分布情况有关,当热源位于吊顶上时,工作区上下垂直温度梯度较大,中间垂直温度梯度较小;当送风温度提高5.7℃时;工作区垂直温差减小70%;工作区0.1 m高度处的空气温度与送风温度之差约占送回风温差的50%.

Experimental measurements were conducted for the temperature distributions in a test ehamber. The test ehamber had internal dimensions of 3.9 m in length, 2.9 m in width and 2.6 m in height. On the basis of analyzing experimental results with six kinds of test conditions, some charaeteristics of indoor air temperature distributions were revealed. The temperature distribution in the oeeupied zone may be eharacterized by vertical temperature gradient （VTG） and the difference between temperature near the floor （at 0. 1 m high） and supply air temperature （SAT）. The results show that the VTG is mainly related to room heat input and room airflow rate. At same room airflow rate, the enhancement of the VTG gets greater than the increase of the differenee between return air temperature（RAT） and SAT, and the ratio of the VTG in the occupied zone to the differenee between RAT and SAT increases from 0. 468 to 0. 573 when the room heat input increases from 324 W to 468 W. Moreover, the vertical temperature profile is dependent on the distribution of room heat sourees. When the heat souree is loeated at the ceiling, the VTG shows obviously in the upper and lower seetions and slightly in the middle one. Further, SAT also affected VTG, when the SAT increased 5.7℃, the VTG in the occupied zone decreased 70%. In addition, the difference between temperature near the floor （at 0. 1 m high） in the occupied zone and SAT approaches to 50% of the difference between RAT and SAT.