1、 40 3360 汉字, 2236 单词, 11500 英文字符 出处: Seshaiah N, Ghosh S K, Sahoo R K, et al. Mathematical modeling of the working cycle of oil injected rotary twin screw compressorJ. Applied Thermal Engineering, 2007, 27(1): 145-155. 英文附录 Mathematical modeling of the working cycle of oil injected rotary twin screw
2、 compressor N. Seshaiah *, Subrata Kr. Ghosh, R.K. Sahoo, Sunil Kr. Sarangi Cryogenics and Gas dynamics Laboratory, Department of Mechanical Engineering, National Institute of Technology, Sector-2, NIT Campus, Rourkela 769008, Orissa, India Received 12 July 2005; accepted 8 May 2006 ; Available onli
3、ne 7 July 2006 Abstract Oil injected twin-screw air and gas compressors are widely used for medium pressure applications in many industries. Low cost air compressors can be adopted for compression of helium and special gases, leading to signicant cost saving. Mathematical analysis of oil injected tw
4、in-screw compressor is carried out on the basis of the laws of perfect gas and standard thermodynamic relations. Heat transfer coecient required for computer simulation is experimentally obtained and used in performance prediction, when the working medium being air or helium. A mathematical model ha
5、s been developed for calculating the compressor performance and for validating the results with experimental data. The ow coecients required for numerical simulation to calculate leakage ow rates are obtained from eciency verses clearance curves. Eect of some of the compressor operating and design p
6、arameters on power and volumetric eciencies have been analyzed and presented. Keywords: Screw compressor; Oil injection; Heat transfer coecient; Leakage; Flow coecients 1. Introduction 41 The screw compressor is a positive displacement machine that uses a pair of intermeshing rotors housed in a suitable casing to produce compression. Screw compressors are capable of high-speed operation over a wide range of operating pressures. In a screw machines, oil is deliberately injecte