Introductory Numerical Study on Supersonic Ejector Working with R32

Department of Power Engineering Equipment, Faculty of Mechanical Engineering, Technical University of Liberec, Studentska 2, 46117, Liberec, the Czech Republic

^* Corresponding author: jan.kracik@tul.cz

Published online: 28 June 2019

Abstract

Nowadays, there is an increasing demand for devices which work efficiently with the smallest possible consumption of energy. In this regard, incorporating ejectors seems to be an interesting choice. This paper describes the numerical analysis of the flow in a supersonic ejector working with R32 (difluoromethane) as the working fluid. The ejector geometry under investigation in this paper has already been experimentally analysed, however, air was used as the working fluid. Therefore, this paper deals with a numerical analysis of the same geometry but with a different working fluid. Furthermore, the design of the ejector enabled the adjustment of a particular distance of the motive nozzle from the beginning of the mixing chamber, i.e. the nozzle exit position (NXP). This work examines the ejector numerically for eleven values of back-pressure with the NXP of two millimetres; consequently, the performance line of the ejector with fixed boundary conditions at both inlets was obtained. Finally, the obtained results are discussed and some recommendations for future research have been made.