Conjugate heat transfer analysis of a twin-screw compressor with 4-6 configuration and internal cooling channels

Abstract

Twin-screw compressor technology is widely employed in commercial and industrial HVAC&R applications as well as in air-compression and gas processing industries. Twin-screw compressors are characterized by relatively high efficiencies at part- and full-loads, and high reliability. However, innovative designs and higher efficiency are needed to further reduce power consumption, improve the compression process, and minimize internal losses. This study focuses on developing a simulation model of a twin-screw compressor with internal cooling channels to achieve a near isothermal compression process. A complex coupling between compression process and heat transfer occurs during the operation of the compressor. To analyze the compressor and the interaction between solid (i.e., rotors) and fluid phases (i.e., air and coolant), a CFD model with conjugate heat transfer has been developed and validated. The CFD model is used to predict compressor performance parameters such as isentropic efficiency, heat transfer rate, work input and pressure forces acting on the rotors. The performance of the twin-screw compressor with internal cooling channels is compared with a conventional twin-screw compressor.