Evaluation of thermal comfort using combined CFD and experimentation study in a test room equipped with a cooling ceiling
Evaluation of thermal comfort using combined CFD and experimentation study in a test room equipped with a cooling ceiling
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DOI：
10.1016/j.buildenv.2008.11.015
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发表时间：
2009-08-01
影响因子：
7.4
通讯作者：
Kuznik, Frederic
中科院分区：
文献类型：
--
作者：
Catalina, Tiberiu;Virgone, Joseph;Kuznik, Frederic
本文报道了在受控条件下安装在测试室内的辐射冷却天花板的全尺寸实验活动和计算流体动力学（CFD）研究。本研究的目的是利用这两项研究的结果，利用预测平均投票（PMV）来分析室内热舒适。在整个实验测试过程中，室内湿度保持在凝结风险最小的水平，并且在天花板的冷冻表面没有检测到凝结。在16.9 ~ 18.9℃的冷却顶温度范围内，对不同工况下的空气温度分布、表面温度和全球温度进行了详细的实验测量，得到了CFD研究所需的边界条件。首先用实验数据对模拟结果进行了验证，然后对风速场进行了研究。研究发现，在脚踝/脚部区域，空气速度可以超过0.2 m/s，而在其他区域，空气速度小于0.1 m/s。不同冷顶温度下的实验结果表明，采用冷顶时，垂直温度梯度小于1℃/m，符合标准建议。地球温度和室内空气温度的比较显示，最大的差异为0.8摄氏度。本文还介绍了用辐射度法计算沿不同轴向不同位置的平均辐射温度。该方法基于观测因子的计算和实验所得的表面温度。PMV图表明，试验室内达到了热舒适，且热舒适分布均匀。(C) 2008 Elsevier Ltd版权所有。
This paper reports a full-scale experimental campaign and a computational fluid dynamics (CFD) study of a radiant cooling ceiling installed in a test room, under controlled conditions. This research aims to use the results obtained from the two studies to analyze the indoor thermal comfort using the predicted mean vote (PMV). During the whole experimental tests the indoor humidity was kept at a level where the condensation risk was minimized and no condensation was detected on the chilled surface of the ceiling. Detailed experimental measurements on the air temperature distribution, surface temperature and globe temperature were realized for different cases where the cooling ceiling temperature varied from 16.9 to 18.9 degrees C. The boundary conditions necessary for the CFD study were obtained from the experimental data measurements. The results of the simulations were first validated with the data from the experiments and then the air velocity fields were investigated. It was found that in the ankle/feet zone the air velocity could pass 0.2 m/s but for the rest of the zones it took values less than 0.1 m/s. The obtained experimental results for different chilled ceiling temperatures showed that with a cooling ceiling the vertical temperature gradient is less than 1 degrees C/m, which corresponds to the standard recommendations. A comparison between globe temperature and the indoor air temperature showed a maximum difference of 0.8 degrees C being noticed. This paper also presents the radiosity method that was used to calculate the mean radiant temperature for different positions along different axes. The method was based on the calculation of the view factors and on the surface temperatures obtained from the experiments. PMV plots showed that the thermal comfort is achieved and is uniformly distributed within the test room. (C) 2008 Elsevier Ltd. All rights reserved.