大空間建築之空調通風效能與耗能研究

A Study of the Performance and Energy Impact of HVAC System in Large Space Building Application

林金童(Jin-Taung Lin)

指導教授 ： 蔡尤溪

國立臺北科技大學/機電學院/機電科技研究所/博士(2010年)

摘要

本文針對大空間建築的空調通風效能及耗能，以量測、解析及CFD氣流模擬等方法進行研究，特別採用台灣的北中南三大都會區的全年氣候資料，分析自然冷卻潛力及滲透對室內環境的衝擊，空調氣室的氣流行為特性，以及在不同的送風條件下，對特定微環境，進行熱舒適指標的研究。
本研究結果發現，因台灣位於濕熱的亞熱帶氣候區，大空間建築的滲透耗能特別的明顯，尤其是建築物氣密性不佳且室內外溫差大者，如滑冰場。有關自然通風潛力的研究發現，在開孔率0.9%以上者都可滿足IAQ的要求，但若考慮自然冷卻的效果，則開孔率必須加大至2%以上，始可有效應用。
本研究發展出以0.15m/s為末端風速的特徵長度，以此做為檢驗空調氣室有否空氣滯留層存在的工具。當氣室的進風紊流區及出風紊流區的二條0.15m/s等速線，沒有交集時，即可證明該氣室存在有空氣滯留層，且可推論該氣室已呈均流狀態，此種簡易的檢驗方法，經由CFD模擬獲得驗證，確認可行。
本研究以每椅柱供風量30m3/h ~ 60m3/h，及19°C~21°C的供風溫度為參數，探討座位微環境內的PMV-PPD指標，結果發現頭腳間的垂直溫差均可維持在3°C以內。同時得知，在相同的供風條件下，衣著量是主要影響PMV-PPD值的因子。因此，利用所產出之PMV-PPD舒適指標，仿逆向工法，可界定出兼顧舒適與節能的最適送風條件。

關鍵字

大空間建築 ； 煙囪效應 ； 計算流體力學 ； 自然通風 ； 滲透 ； 置換式空調

並列摘要

This thesis is a study on the system performance, energy efficiency, and air flow behavior of HVAC system in single cell large space buildings. The research results are base on measurements, analysis, and CFD simulation, with year-round climate data, covering metropolitan areas in northern, middle and southern Taiwan. The thesis also examines the thermal comfort under various air supply designs for the seating areas.
It was found in the study that large buildings in Taiwan as they are located in hot and humid sub-tropical climatic zone have high energy consumption due to infiltration. The infiltration is especially high for those with high temperature difference between indoor and outside, amplified by air leakage. The thesis also shows that natural ventilation due to stack effects can meet IAQ requirement when the opening to floor ratio reaches 0.9% or above. However, to satisfy thermal comfort with natural cooling effect, the opening to floor ratio has to reach at least 2%, for an effective period of natural cooling to reach 4 months in one year.
For even air distribution with displacement cooling under audience seating, this study has found that an air stagnant layer 0.15m/s is in the air chamber is an important indicator. This study developed a simple method to verify whether an air stagnant layer exists by using equal-velocity contours that appears in both air inlet and air outlet zones. It has been shown that the existence of an air stagnant layer will ensure air outlet uniformity.
In the study of air comfort for audience area, perforated column type of air outlet under the seating was study for different flow rates and air supply temperatures. Indices such as PMV-PPD were used in the evaluation by using the CFD simulation results. The result shows that the vertical temperature difference between head and ankle can be kept within 3°C. Also, under the same supply air condition, the clothing is the key factor that can influence the PMV-PPD indices. Most appropriate supply air conditions were proposed that can be used to determine the requirements of both thermal comfort and energy-saving.

並列關鍵字

Large space building ； Stack effect ； CFD ； Natural ventilation ； infiltration ； displacement air conditioning

參考文獻

[112]郭勝琪，室內體育場所空調氣流對舒適度之影響研究，國立臺北科技大學能源與冷凍空調工程系，碩士學位論文(未出版)，2008。

[2]T. Nishioka, K. Ohtaka, N. Hashimoto, H. Onojima, 〝Measurement and evaluation of the indoor thermal environment in a large domed stadium,〞Energy and Buildings, vol.32, no. 2, 2000, pp. 217-223.

[3]C. Huang, Z.J. Zou, M.L. Li, X. Wang, W. Li, W.G. Huang, J.G. Yang, X.Q. Xiao, 〝Measurements of indoor thermal environment and energy analysis in a large space building in typical seasons,〞Building and Environment, vol.42, no.5, 2007, pp.1869-1877.

[4]M. N. A. Said, R.A. MacDonald, G.C. Durrant, 〝Measurement of thermal stratification in large single-cell buildings,〞Energy and Buildings, vol. 24, no. 2, 1996, pp. 105-115.

[5]M.N.A. Said, 〝Measurements of air change rates and air flow patterns in large single-cell building,〞Energy and Buildings, vol.26, no. 2, 1997, pp. 175-182.