A CFD study on the indoor environment using an UnderFloor Air Distribution System

• Main Authors: Zi-An Lin, 林子安
• Other Authors: Yi-Jiun Peter Lin
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/11821316873601847615

碩士 === 國立臺灣科技大學 === 機械工程系 === 103 === The research presents a CFD study of the indoor thermal environment. The process and setting parameters of numerical simulation method are introduced. CFD program uses the finite volume method and a standard two-equation k-ε turbulence model to calculate air flow and temperature distribution in the building. The UFAD system supplies conditioned air from the raised floor to the indoor space and hot air is extracted to return vents at ceiling. Comparing the simulation results with experiment, it is found that there are significant deviation between the simulation results and experiment results. There are difference between the overall heat transfer coefficient U = 1.49 W/m2K of simulation and the experiment data at the same heat convection transfer coefficient h = 3 W/m2K of the glass curtain. By changing the wall heat transfer coefficient, the result is closer to the experiment when the heat convection transfer coefficient is h = 20 W/m2K and the overall heat transfer coefficient is U = 9.45 W/m2K. This study investigates different supply air conditions at fixed heat convection coefficient h = 20 W/m2K to detect the vertical temperature distribution curve, the stratification height and the throw height. We not only observe the temperature distribution at the stratification height along the horizontal plane, but also the temperature distribution and velocity vector at the center of the supply diffuser along the vertical plane. The results reveal that increasing the wind speed causes the temperature stratification height and the throw height to rise, but does not affect the average room temperature according to the fixed supply air rate and supply air temperature. When the air supply rate increase, the temperature stratification height and the throw height rise, and also have a significant influence on the average room temperature according to the fixed supply air velocity and supply air temperature.