Examination of Ejector Parameters in Solar Powered Refrigeration Systems

The effect of the design parameters on the performance of solar powered ejector refrigeration systems is investigated for typical values of the heat input and condenser temperatures. Seven different hydrocarbon fluids and water are investigated as potential working fluids. The hydrocarbon fluids have thermodynamic characteristics which allow the primary fluid to enter the ejector at its maximum pressure for a specified heat input temperature. The ejector performance is increased by a factor of two when the primary fluid velocity is increased from a Mach number of 0.1 to 0.9. One advantage of using these fluids is the small size of the system. Based on these results, a system with a constant pressure mixing ejector which uses isobutane will produce the best performance for a heat input temperature and condenser pressure of 355 K and 728 KPa, respectively. The results are summarized in a set of graphs that can be used to choose the working fluid and ejector configuration for a particular application.