Volume 5: Innovative Solutions for Energy Transitions: Part IV

Analysis of a Low-Temperature Heat Driven Vapour Compression Cooling System Incorporating a Super-Sonic Ejector Fahid Riaz, Poh Seng Lee, Ravi Ranjan, Siaw Kiang Chou

Abstract

Vapour compression cycle (VCC) is widely used technology of cooling and air-conditioning. Low-qualityindustrial-waste-heat driven ejector refrigeration systems (ERS) are promising solutions but limited by lower efficiency and larger system sizes. This paper presents the analysis of a new system which enhances the electrical-COP of the VCC by incorporating supersonic ejectors driven by heat. This new system, ejector-enhanced-vapour-compression-cycle (EVCC), increases the electrical-COP of the whole system while harnessing low-grade-waste-heat. Engineering Equation Solver (EES) has been used to model the system equations and the system performance is compared with VCC, Enhanced-ERS, and ejection-compression-system. In the analysis, R245fa has been used as the working fluid. The proposed system gives lower global-COP value as compared to conventional-VCC and ejectioncompression-system because this system is designed to be able to extract as much heat as possible from waste stream, therefore, higher electrical-COP is the focus of this proposed system. It is concluded that, for the base case, the proposed EVCC gives higher value of electricalCOP as compared to all the other three systems.

Keywords Vapour Compression, Ejector, Energy, Waste Heat, Refrigeration, Efficiency