Combined Numerical and Analytical Analysis of an Oil-free Twin Screw Compressor

10th International Conference on Compressors and their Systems

Kennedy, Stuart^1 ; Wilson, Maria^1 ; Rane, Sham^2

Howden Compressors, Old Govan Road, Ranfrew

PA4 8XJ, United Kingdom^1

City, University of London, EC1V 0HB, United Kingdom^2

关键词: Complex internal flow;    Degree of certainty;    Discharge temperature;    Key performance indicators;    Modelling techniques;    Operating characteristics;    Three dimensional computational fluid dynamics;    Volumetric efficiency;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/232/1/012080/pdf
DOI  :  10.1088/1757-899X/232/1/012080

来源: IOP

【 摘 要 】

The application of three-dimensional computational fluid dynamics in twin-screw compressors provides an outstanding opportunity for developers to gain an understanding of the complex internal flow phenomena occurring within the machine. Equipped with this knowledge, design parameters, such as clearances and port geometry, can be optimised, to enhance performance. However, as with all modelling, be it numerical or analytical, a high degree of certainty in the accuracy of the results is necessary. This paper presents the results of a study of oil-free twin screw compressor in which the results of two modelling techniques are compared. The modelling techniques used are an analytical non-dimensional thermodynamic chamber model and a numerical computational fluid dynamic model. The paper presents an overview of an oil-free twin screw compressor machine, before describing important operating characteristics and the modelling techniques used. To validate, both models are compared against historical test data, this validation indicated the chamber model is more accurate. Following this, the focus will be on the comparison of key performance indicators, including, volume flow rate, volumetric efficiency, indicated power, and discharge temperature at varying duty points. The paper concludes that the difference between both models decreases as the compressor operating speed increases, although the level of variance is dependent on pressure ratio.