全凍結式儲冰槽溶冰熱傳性能研究

Abstract

本研究建立內溶冰型圓型槽體水平盤繞式「儲冰槽擬穩態模擬程式」，並以此作為分析工具，探討儲冰槽溶冰熱傳與「儲冰槽溶冰熱交換有效性(ε)」關係、「溶冰盤管總熱傳係數(UAC)」之組成參數分析、儲冰槽參數的變化，其中包含「儲冰槽滷水流量(Vb)」、「儲冰槽盤管層數(N)」、「盤管材料熱傳導係數(Km)」對儲冰槽溶冰熱傳性能影響。 本研究進一步藉模擬工具分析目前常用儲冰槽規範瑕疵，並提出以「儲冰槽溶冰熱交換有效性(ε)」概念制定一新的儲冰槽規範；此儲冰槽規範最大優點為改善了以往儲冰系統測試可行性問題；另以此規範檢驗總負荷相同之「負荷固定」、「負荷遞增」、「負荷遞減」3種類型負荷，模擬結果顯示儲冰槽槽體需分別加大1.18倍、1.32倍和不需加大；本研究希望藉由對儲冰槽熱傳性能之分析，及改善目前儲冰系統規範之盲點，期能使相關領域人員更加了解儲冰槽特性，以利於儲冰系統推廣使用。

The study builds a numerical model of a round- type horizontal- twined total-freeze-up Ice Storage Tank (IST). This model tool can be use to analysis the relationship of the IST‘s discharge heat transfer characteristic and heat exchange effectiveness (ε), the combined parameter of total discharge heat coefficient (UAC), the discharge heat transfer characteristic effective of changing IST‘s parameters which include IST‘s brine flow rate (Vb), total number of coils inside the tank (N) and thermal conductivity of coil‘s material (Km). The numerical model can be further analysis of the imperfect of present IST‘s standard and proposing a conception of using the discharge heat exchange effectiveness (ε) to build a new IST‘s approach. The major contribution of this IST‘s approach could solve the existing problem of testing feasibility. Further more, the study use the new IST‘s approach to examine 「the fixed load」, 「the progressively increasing load」and 「the progressively decreasing load」. These three type of load have the same total load. The numerical result shows that IST‘s capacity have to increase 1.18 times, 1.32 times and unchanged separately. The study can use as a design information to help personnel in the air conditioning field to understand the IST‘s characteristic for HVAC system.