壓縮機熱場及流場的模擬

Simulation of Heat and Fluid Flow in Compressor

林剛立(Gang-Li Lin)

指導教授 ： 陳慶耀

國立交通大學/工學院/機械工程系所/碩士(2019年)

摘要

本研究為使用商用軟體—ANSYS Fluent模擬車用往復式壓縮機的運動情形。當壓縮機在作動時，低溫液態冷媒從壓縮機的入口流入，經過活塞壓縮後，成為高溫高壓的氣態冷媒並從出口流出。本研究利用Fluent得到冷媒 ── R-134a在壓縮機內流場的壓力及溫度分布，出口的壓力、溫度、質量流率及壓縮機所作的功。在建模的部分，模型以壓縮機的實際尺寸而建，並且只建於流體所經之處，使模擬的準確度、難度及時間都可以兼顧。模擬方面，使用動網格及SST k-ω turbulence model模擬。本研究所改變的參數為入、出口閥門的最大開度，壓縮機轉速(活塞壓縮頻率)以及活塞衝程。當入口閥開度固定時，出口壓力、溫度及活塞作功會隨著出口閥開度上升而下降。當出口閥開度固定時，出口溫度及活塞作功會隨著入口閥開度上升而下降，出口壓力則是會隨著入口閥開度上升而上升。出口壓力、溫度及活塞作功會隨著壓縮機轉速及活塞衝程上升而上升。以前述的結果配合質量流率以得到最佳的結果。

關鍵字

壓縮機 ； 動網格 ； 計算流體力學 ； 紊流模型

並列摘要

This study used commercial software ANSYS Fluent to simulate the motion of reciprocating compressors for vehicles. When the compressor operates, low temperature liquid refrigerant flows into compressor. After being compressed by the compressor piston, it becomes high temperature and high pressure gas and flows out. The thermodynamic properties of the fluid were represented by real gas R-134a. Fluent was used to obtain the pressure and temperature distribution of the refrigerant in the compressor. The model was designed based on a swash plate compressor. In order to reduce the calculation time and difficulty of creating the model and running the simulation, only part of the compressor volume was used to create the model, such parts were one of the six compressor cylinders, the inlet and outlet valves and the inlet and outlet receivers. Dynamic mesh and SST k-ω turbulent model is used in the simulation. The parameters changed in this study are the angle of valves, shaft rotating speed and stroke of the piston. If the angle of inlet valve is fixed, the pressure, temperature and the work of piston will decrease as the angle of outlet valve increased. If the angle of outlet valve is fixed, the temperature and the work of piston will increase, the pressure will decrease as the angle of inlet valve increased. The pressure, temperature and work of piston will increase as the shaft rotating speed and stroke of the piston increase. In order to get the best outcome, mass flow rate is combined with the previous results.

並列關鍵字

compressor ； dynamic mesh ； CFD ； turbulence model

參考文獻

[1] D. Taranović, D. Ninković, A. Davinić, R. Pešić, J. Glišović and S. Milojević, “valve dynamic in reciprocating compressors for motor vehicles”, Tehnički vjesnik 24, Suppl. 2(2017), 313-319.

[2] M. Udayakumar, K. Pannir selvam and T. Suthakar, “In Situ Performance Evaluation of Industrial Reciprocating Air Compressors”, International Compressor Engineering Conference (2008), 1422 1－7.

[3] 鄭國豐, “壓縮機活塞缸之流場模擬” , 國立雲林科技大學機械工程所碩士班碩士論文, 2007.

[4] C. J. Deschamps, R.T.S. Ferreira and A.T. Prata, “Turbulent Flow Through Valves of Reciprocating Compressors”, International Compressor Engineering Conference (1996), 377－382.

[5] J. Park, N. Bilal, D. E. Adams, Y. Ichikawa, J. Bayyouk, “Numerical and Experimental Studies of Gas Pulsations in the Suction Manifold of a Multicylinder Automotive Compressor”, Journal of Vibration and Acoustics (2008), 011014 1－11.