空氣源熱泵熱水器最佳運轉性能之研究

Study of Optimum Operating Performance for Air Source Heat Pump Water Heaters

黃偉強(Wei-Chiang Huang)

指導教授 ： 李宗興

國立臺北科技大學/機電學院/能源與冷凍空調工程系碩士班/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00055

摘要

採用單級蒸氣壓縮冷凍循環操作之空氣源熱泵熱水器，當其運轉於低溫環境溫度(-5~-25℃)時將面臨許多問題，例如: 壓縮機之壓縮比過大、蒸發器之入口乾度變大、及壓縮機之排氣溫度升高，這些都將使機組的運轉性能變差。因此，探討如何使空氣源熱泵熱水系統於低溫環境溫度運轉時，能克服上述之問題，並使效率提高，就成為此類設備開發之重要課題。本文主要研究目的為: 以具有節能器之R404A空氣源熱泵熱水器作為研究對象，藉由理論模擬方式進行參數分析，探討在不同操作條件下，中間壓力調節對最佳運轉性能之影響。研究結果發現：準二級循環較單級循環整體性能約可提高17%;系統冷媒由R-22改為R404A平均可提高整體性能約8%;當其在不同操作條件下(不同之冷凝與蒸發壓力變動下)，使用準二級蒸氣壓縮製熱循環之R404A空氣源熱泵熱水器系統，存在有一最佳中間壓力值，並對應一最佳運轉效率;最佳中間壓力發生於接近冷凝壓力與蒸發壓力之幾何平均值，本文所得之結果皆與Cao(2009)相同。

關鍵字

空氣源熱泵熱水器 ； 渦卷式壓縮機 ； 準二級壓縮 ； 最佳中間壓力

並列摘要

While single stage air source heat pump water heater runs in conditions of low ambient temperature(-5~-25℃), it will face some problems. Such as: Compression ratio of the compressor will be oversized, the evaporator inlet quality will increase, and the discharge temperature of compressor will increase. Therefore, if air source heat pump water heater runs in conditions of low ambient temperature, it can overcome the above problem, and make the high efficiency. It’s important to development equipment. The objective of this study is, through theory simulation parametric analysis adjusting the intermediate pressure to change system performance for quasi-two stage air source heat pump water heater with economizer and R-404A in different operating condition. The results show that: quasi-two stage air source heat pump water heater can increase the coefficient of performance about 17% than single stage. The refrigerant using R-404A can increase the coefficient of performance about average 8% than R-22. In different operating condition(condensing pressure and the evaporation pressure), the system uses quasi-two stage air source heat pump water heater with economizer and R-404A, There will be a maximum value of the heating coefficient of performance and the coefficient of performance correspondence for optimum intermediate pressure. The optimum intermediate pressure occurs closely to the geometry of mean value condensing pressure and the evaporation pressure. The obtained result of this study equivalent to Cao(2009).

並列關鍵字

air source heat pump water heater ； scroll compressor ； quasi-two stage ； optimum intermediate pressure

參考文獻

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