淺層溫能應用於空調系統散熱

Abstract

一般的大型空調系統通常使用冷卻水塔將冷凝熱排放至大氣中，然而，冷卻水塔的散熱性能卻受制於溫溼度變化大的大氣環境，除此之外，冷卻水塔運轉時還會產生擾人的噪音與振動，水塔中的水更會成為孳生病菌的溫床，助長退伍軍人症的傳播，存在著諸多缺點，故本論文欲利用溫度較外氣低溫且穩定的淺層地表溫能做為空調的散熱源，透過宜蘭實驗場的實地測試，探討以淺層溫能做為空調散熱源、取代冷卻水塔的可行性。本研究所使用的淺層溫能型式共有兩種：地表鑽井內的地下水溫能，以及建築物底部的地下筏基水溫能。實驗結果顯示：空調系統的性能係數COP在使用地下水散熱時為4.4，優於使用筏基水散熱時的4.1。使用地下水散熱可使系統達到熱平衡，穩定地將冷凝熱排放至淺層地表當中，是使用冷卻水塔散熱之外的另一種選擇；然而，使用筏基水散熱將使筏基內水體不斷地蓄積熱量而持續升溫，因此在操作上仍需再做調整，方能發揮筏基水的最大效益。

Traditional air-conditioning cooling systems usually use cooling tower to dissipate condense heat into outdoor air. However, the outdoor temperature and humidity, which vary over time, limit the cooling performance of cooling tower. Furthermore, the use of cooling tower has many disadvantages such as noise, vibration, and also providing a proper environment for bacteria breeding. Therefore, the aim of this thesis is to replace cooling tower system with a new cooling system—the shallow geothermal cooling system. This new cooling system dissipates condense heat into the shallow ground. Because of having a relatively small temperature variation, the shallow ground can be a stable heat sink for air-conditioning cooling.In this study, we used two types of shallow geothermal cooling system: groundwater borehole and raft foundation water. According to the experiment results, the groundwater cooling system could stably cool the condenser and reached thermal equilibrium state, but the temperature of raft foundation water was continuously rising during operation. Therefore, the groundwater cooling system can be a proper alternative for replacing cooling tower system. On the other hands, the raft foundation water cooling system could be another choice through optimized operating method.