水簾式空調通風系統之熱流場及舒適度模擬分析

Analysis of the Thermal Flow Fields and Thermal Comfort for a Ventilation System with a Cooling Pad

廖彥棋(Yen-Chi Liao)

指導教授 ： 朱存權

國立虎尾科技大學/工程學院/機械與機電工程研究所/碩士(2012年)

摘要

地處亞熱帶的台灣，夏天在空調用電所佔的能源消耗相當大，如何使空調用電量降低，對節能減碳改善將有相當大的助益。由於一般空調系統其壓縮機所佔耗電量最大，若能借助自然熱交換方式來適當降低空氣溫度，達到讓人可接受的環境，則可明顯降低能源消耗量。其中水簾式空調通風系統即為構想之一，其原理是引導空氣通過經水潤濕的水簾，使水簾間的水滴吸收空氣熱量蒸發，進而降低流入室內的空氣溫度，以達室內降溫需求。然其系統安裝設計時空氣進口位置的選定，對整個室內溫度分佈有明顯影響。因此有必要針對不同空氣進口位置，做合宜的設定以達降溫舒適的效果。
本研究利用計算流體力學套裝軟體ANSYS CFX 針對安裝水簾式空調通風系統的工廠進行室內三維暫態紊流之溫度、速度、濕度統御方程式數值求解，分析室內溫度場、速度場及濕度隨時間變化之情形。進而將計算結果代入熱舒適度指標計算式，以瞭解室內的熱舒適度分佈情形。探討人員於空間中高度1.5公尺之截面的舒適感受。結果顯示在空間中未加入強制對流的案例因浮力效應作用而使冷空氣聚在空間下方，讓高度1.5m之截面降溫速度較快。本研究衡量區域之設定，案例1在熱舒適度及預測不滿意度的分佈結果較其他案例為佳，對此工廠空間而言為適合之配置方案。

關鍵字

水簾式空調通風系統 ； 熱舒適度 ； 預測不滿意度

並列摘要

Taiwan locating in the subtropical area consumes a lot of energy on air condition in summer. Therefore, to save the energy from air conditioning is very helpful for the energy saving and carbon reduction. Usually, the compressor uses the largest portion of air conditioning energy consumption. If we can lower the air temperature by using a natural heat-exchange way, it can significantly reduce the energy consumption. A ventilation system with a cooling pad belonged one of these ways, it is mainly to decrease the temperature of air that flows into house by transferring heat to the vaporization water drops. The installing design and the location choice of air flow entrance for this system are very important to the indoor temperature distribution. Therefore, it is worthful to investigate different flow inlets, and to make an appropriate arrangement for achieving a thermal comfort condition.
In this study, computational fluid dynamics software, ANSYS CFX, is used for simulating three-dimensional transient indoor air flow for a factory which installs a ventilation system with a cooling pad. The indoor temperature, velocity field and humidity distribution are studied. And the predicted mean vote and predicted percentage of dissatisfied are calculated to understand the distribution of indoor thermal comfort. The thermal comfort of this factory space is investigated by evaluating the PMV and PPD values on the cross section of 1.5 meters high. The results showed that, most cold air exists in the lower part of space due to buoyancy effect, resulting in cross sections of Y=1.5m cooling faster.
Based on the evaluation area set in this study, case 1 presents better PMV and PPD distributions and it is a suitable arrangement for the studying factory space.

並列關鍵字

ventilation system with a cooling pad ； PMV ； PPD

參考文獻

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