Investigation of the scroll compressor porting process. Part I: global flow physics and behaviour of gas pockets

Abstract

The three-dimensional time-dependent porting process of a scroll compressor is investigated numerically. In the first part of the investigation, the porting flow is examined in the background of an integrated compressor working process. The compressor studied includes the upper bearing housing, scrolls, check valve, and discharge plenum. The Navier-Stokes equations with a k-ɛ turbulence model are solved at the standard operating condition of the scroll compressor. Refrigerant-22 is used as the working fluid. The thermodynamic and transport properties of the refrigerant gas are modelled by the Martin-Hou equation of state and power laws, respectively. Global flow physics is investigated first to lay a foundation to understand the working mechanisms that control the porting process before averaging techniques are applied. The behaviour of the gas pockets in the porting process is characterized in both geometric and dynamic nature. The time-dependent variation of volume, mass, energy, and volume-averaged field quantities inside the gas pockets is studied throughout the porting process. The performance of the given compressor design during the porting process is defined.