渦卷間隙對渦卷式壓縮機影響之數值分析

Numerical Analysis on the Scroll Gap and Effect of the Scroll Compressor

陳宥中(You-Chung Chen)

指導教授 ： 蔡建雄

國立屏東科技大學/工學院/車輛工程系所/碩士(2013年)

https://doi.org/10.6346/NPUST.2013.00291

摘要

本研究主要探討渦卷式壓縮機在徑向及軸向上的洩漏情形，由於動渦卷、靜渦卷間必然存在一間隙，影響壓縮效率甚多，加上壓縮機內部流場不易進行觀察，因此透過計算流體力學來建立渦卷壓縮機內部流場的模擬技術。
為了瞭解相關參數的變化對於工作腔內壓力的影響，且使模擬更具真實性，同步進行不同轉速、壓差、排氣閥、齒高機構的研究，透過技術的建立，能夠做為未來開發渦卷式壓縮機時，改善其壓縮效率的工具。
模擬結果發現：(1)冷媒由渦卷間隙洩漏速度受到間隙大小的影響較大，受到背壓差的影響較小。(2)冷媒在工作腔內隨動渦卷前進時，受到軸向間隙的影響呈迴旋狀前進。(3)進排氣口之背壓差對於質量流率的影響不大，但對馬達耗功影響甚大。(4)使用排氣閥機構會減少質量流率。(5)使用齒高機構能夠有效的提升壓縮壓力。

關鍵字

計算流體力學 ； 渦卷式壓縮機 ； 渦卷間隙 ； 洩漏氣流分析

並列摘要

This study focuses on the leak situation of scroll compressor in radial and axial direction. There must be a gap between orbiting and fixed scroll, results in greatly effects of compression efficiency. And the difficult observation on the inner flow field of compressors. So we establish the simulation technique of the inner flow field of scroll compressors by using computational fluid dynamics.
To realize the changes of parameters due to the different pressure in working chambers, we doing research simultaneously with different rotational speed, pressure difference, exhaust valve, and step mesh gaps. By establishing technique, we can improve scroll compressors’ compression efficiency when developing them in the future.
The simulations’ results are as follows:
(1)The leakage rate of refrigerant is affected more from scroll compressors’ gap than from pressure difference. (2)The refrigerant in working chambers follows orbiting scrolls’ operation, and it flows spirally due to the axial gap. (3)The pressure difference between intake and exhaust has a less effect on mass flow rate, but it affects consumed power of motors to a considerate degree. (4)Using exhaust valve mechanism will reduce mass flow rate. (5)Using step mesh gaps can effectively enhance compressor pressure.

並列關鍵字

CFD ； Scroll compressor ； Scroll gap ； leakage flow analysis

參考文獻

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7. 王偉勳，2012，代數螺旋線型渦卷式壓縮機之三維熱流場數值模擬分析，碩士論文，臺北科技大學，能源與冷凍空調工程學系研究所，臺北。