地埋管空調系統性能分析

Abstract

本研究即是利用土壤恆溫性佳的特性，在南投某員工餐廳架設地埋熱交換器系統（以下簡稱地埋管），透過風機將外氣引入地埋管，讓空氣在進入原有空調箱前先行與土壤進行熱交換，達到預處理外氣的目的，藉以降低空調之耗能。 由實驗數據得知，7~9月夏季時，外氣平均溫度約34.6oC，經過與土壤進行熱交換，可使地埋管出口端溫度約為28.6oC，溫降達6oC之多；12~2月冬季時，外氣平均溫度約22.4oC，經地埋管加溫後，出口端約22.8oC。台灣夏季多高溫炎熱，因此地埋管系統適用於夏季降溫之作用。將結合地埋管的空調系統與直接引進外氣之傳統空調系統進行節能比較，於夏季時可節省約20%之能源耗費。 地埋管系統於冷卻過程中，會伴隨冷凝水的產生，冷凝水的積聚可能致使微生物孳生影響運轉效能，因此本研究第二部分選用可自行調節濕度的調濕材料-矽藻土，將其塗抹於PVC管進行吸放濕測試，目的為降低管內空氣濕度，再加上矽藻土附加的除臭、殺菌等功能，能使地埋管出口端空氣品質提升。在入風RH 60%、RH80%之情形下，測試結果矽藻土擁有吸濕能力；在入風RH 40%之情形下，測試結果矽藻土擁有脫附的能力。將矽藻土實驗結果與地埋管系統做結合，若將矽藻土塗抹於入風處之垂直管段，可節能約17%；若塗抹於出口端之垂直管段，可節能約11%；兩者皆塗抹的情況下，可節能約25%。

This research applied the soil to cool down the outdoor air by using earth to air heat exchangers, also called as EAHE. The characteristics of soil temperature remain constant in summer is designed for building an EAHE in the employee's cafeteria in the midst of Taiwan. Outdoor air was pulled by the fan blower into the EAHE, so that the air is pretreated before entering the air conditioning system. This work aimed at lower cooling load of air conditioner and consumption of electricity. In summer, the outdoor air temperature can reach above 34 degree Celsius. It can be found that under the use of EAHE, the dry bulb temperature difference between outdoor air and outlet air of EAHE is higher than 6oC. On the other hand, the outdoor air was also heated by EAHE in winter. Taiwan locates in the subtropical climate region, so that the EAHE has the better performance in summer when it was used to reduce heat load of air conditioner. The experimental results reveal that the air conditioning system combined with EAHE can effectively reduce 20% of energy consumption. The condensed water may appear in the cooling process of EAHE. However, accumulation of condensed water may cause the breed of bacteria and also effect the quality of outlet air. In the second part of this research, a humidity control material, diatomite, was applied to PVC pipe to test its adsorption ability, aimed at reducing the inner tube humidity. The results show that when the diatomite was exposed to the air with RH 60% and RH 80%, it has the ability of adsorption. On the other hand, when the diatomite was exposed to air with RH 40%, it has the ability of desorption. If diatomite smear on the vertical segment of the inlet part of EAHE, the energy savings is about 17%; if applied in the exit part of the vertical pipe sections, energy savings is about 11% Energy savings is about 25% when diatomite was smeared on inlet and exit part.