具製熱與儲熱一體自然對流熱泵之熱傳實驗研究

本研究擬開發之熱泵，其具製熱與儲熱於一體，採用一種創新之自然對流熱傳機構製熱，達到冷熱得以分流減少邊界層厚度，增強自然對流熱傳的效果，為當今產業或文獻尚未提到的創新型熱泵。本研究熱泵循環之冷凝器採用繞管置於儲熱桶，不須用水循環泵，減少消耗循環泵電力上，是一種具有前瞻之綠能科技產品。產生熱對流循環於冷凝器及儲槽之間，且將熱泵與儲槽兩者結合為一體，具有儲熱與製熱之效果。本研究已建置一體式熱泵之實驗機，冷凝器與儲水槽為一部件，另壓縮機、蒸發器及冷媒控制為另一部件，兩部件合為一體之自然對流熱泵。本研究將200公升的水由25oC加熱至60oC，並且於儲水桶內佈感測點觀察其熱分層變化，求出每層熱分層狀況、自然對流係數、熱泵性能係數(COP)。實驗結果分析後，將200公升的水由25oC加熱至60oC所需加熱時間為83分鐘，冷凝器之熱交換能力為5.56kW，自然熱對流係數為1.34kW/m2oC，壓縮機耗電為2.74kW，平均COP為2.03。此外，本研究以實驗結果探討冷熱分流對於增強自然對流之效果，於儲熱桶內建置一機構將螺旋管式冷凝器圍住，可以有效地阻擋冷水引入時所發生的混水現象，銅管壁與創新冷熱分流間距分別有1cm、2cm、4cm三種型式，平均靜態加熱之自然熱對流係數為1.47kW/m2oC(1cm)、1.26 kW/m2oC(2cm)、1.23 kW/m2oC(4cm)。

關鍵字

熱泵；儲熱；自然對流；冷熱分離；綠能產品

並列摘要

The heat pump investigated in this study combines heating and water storage as one apparatus. The condenser coil of heat pump was installed in the water storage so to eliminate the circulation pump for energy saving. A natural heat convection enhancement that separates the paths of hot and cold water flow so to reduce the boundary layer thickness was studied experimentally. A one body package heat pump experiment was set up with the condenser in the water tank, and the compressor, the evaporator and the refrigerant control installed above the water tank so combined into one apparatus. Tests were carried to heat 200 liters of water from 25oC to 60oC. Temperature Sensors were setup in the tank and on the condenser to study the thermal cline, the natural convection heat transfer coefficient, the heating rate and the coefficient of performance of the heat pump (COP). The experimental results showed that heating 200 liters of water from 25oC to 60oC required a heating time of 88 minutes. The average heating rate of the condenser is 5.56kW. The corresponding natural convection coefficient is 1.34kW/m2oC. The average compressor power was 2.74kW. Thus the average heat pump COP is 2.96. Further experiments on the effects of hot cold flow separation natural convection were conducted. A separation of surrounding the center spiral condenser was installed to prevent the mixing of cold water with the hot water. Three spacing of between the copper tube and the separation were tested, 1cm, 2cm, and 4cm. The respective average water heating natural convection coefficient are 1 .47kW/m2oC, 1.26 kW/m2oC and 1.23 kW/m2oC.

並列關鍵字

heat pump ； heating storage ； natural convection ； green energy equipment

參考文獻

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具製熱與儲熱一體自然對流熱泵之熱傳實驗研究

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