渦卷式冷媒壓縮機壓縮室熱流場特性之數值模擬分析

Numerical Study of Thermal-Fluid Field of Refrigerant Scroll Compressor Chamber

楊哲明(Chol-Ming Yang)

指導教授 ： 黃博全

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)

摘要

由於近年來人們對冷媒壓縮機的性能要求趨向於高效率、高可靠度、低噪音與低成本，而渦卷式壓縮機除了符合上述之條件外且有元件少、運作原理簡單等多項優點，因此深受市場歡迎，並被大量使用在中低噸位的空調機上。
本文以漸開線型渦卷式壓縮機作為基礎，利用數值模擬方法-計算流體力學(CFD)探討壓縮室內流體的速度、溫度、壓力、熱傳等熱流場特性，並以漸開線作為基礎曲線，衍生發展其他渦卷式壓縮機之渦卷線-非等厚之對數螺旋線當渦卷線，以期進一步探討渦卷式壓縮機的特性，使之更能達到節能減碳。
研究結果顯示：（1）壓縮室內流場是由壓縮室之幾何形狀與旋轉速度決定；（2）壓縮室內流體的速度隨者轉動角度增加而減慢。在壓縮室兩側的尖端會有高紊流；（3）壓縮室內流體的溫度並非均勻的分佈，特別是在壓縮室的兩尖角處與壁面，而影響流體溫度除了壓縮效應外，亦與流體和渦卷壁面間的對流熱傳有關；（4）在壓縮過程中流體之紊流強度會取代流體的速度成為影響渦卷壁面上的對流熱傳的要角；（5）該熱傳量會隨流體進口壓力與旋轉速度增加而增加；（6）相較於傳統漸開線渦卷，對數螺旋線渦卷壓縮機具有較高的壓縮比(增加約10~15％)與較大冷媒吸入量，可達到提升渦卷式壓縮機效能之目的。

關鍵字

計算流體力學 ； 渦卷式壓縮機 ； 對流熱傳

並列摘要

Recently, the requirements for the performance of refrigerant compressor tend to be high efficiency, high reliability, low noise and low-cost. Moreover, the scroll compressor satisfies not only the above-mentioned features but also the features of fewer components and simple operational principle. As a result, the compressor becomes popular in the market and is widely used on low-tonnage air conditioner.
In this study, based on an involute scroll compressor, the numerical simulation - Computational Fluid Dynamics (CFD) were used to explore the features of unsteady thermo-fluid fields inside the compression chamber, such as speed, temperature, pressure, and heat transfer. Using the linear involute as a basic curve to derive other scroll compressor’s scroll curve and non-equal thickness of the logarithmic spiral with a view to further exploring the characteristics of scroll compressor, which can achieve energy saving.
The results reveal that (1) the flow field in the compression chamber is determined mainly by the scroll chamber geometry and the operational speed of the compressor; (2) the interior fluid speed of the compression chamber decreases with increasing in rotation angle, and there is high turbulent flow on the cutting-edge of the compression chamber; (3) The gas temperature is spatially non-uniform particularly at the region near the two apexes and the scroll chamber walls, which depends strongly on both the compression effect and the convective heat transfer between the gas and the scroll walls; (4) During the late period of the compression process, the turbulence intensity instead of the gas velocity becomes a main factor governing the heat transfer near the scroll wall; (5) The magnitude of heat transfer increases with the operating pressure and the rotating speed; (6) compared to the traditional involute scroll, the logarithmic spiral compressor equip with higher compression ratio (an increase of about 10 ~ 15%) and with the larger inlet amount of refrigerant, which can serve performance enhancement of the scroll compressor.

並列關鍵字

CFD ； Scroll compressor ； Convective heat transfer

參考文獻

[2] 賴慶峰，“R-410化對渦卷式壓縮機重要元件應力變化影響之個案討論”，中國冷凍空調雜誌，pp. 90-94，(1998)。

[9] 黃錦文、張永鵬、蔡瑞益，“淺談渦卷式壓縮機工作原理與設計初步(上)”，冷凍與空調，第16期，pp. 76-85，(2002)。

[11] 黃錦文、張永鵬、蔡瑞益，“淺談渦卷式壓縮機工作原理與設計初步(下)”，冷凍與空調，第18期，pp. 72-86，(2002)。

[19] 張鈺炯，“深談渦卷式冷媒壓縮機”，中國冷凍空調雜誌，pp. 91-99，(1997)。

[5] K. T. Ooi, J. Zhu, “Convective heat transfer in a scroll compressor chamber: a 2-D simulation”, Int. J. thermal science, Vol. 43, pp. 677-688, (2004) .