Theoretical analysis of a novel liquid-vapor separation condensation ejector refrigeration cycle with zeotropic mixtures

This paper presents a novel liquid-vapor separation condensation ejector refrigeration cycle (LERC). The zeotropic mixture (R245fa/R134a) is used as the working fluid. And the fluid composition of primary and secondary flow are controlled by a heat exchanger and liquid-vapor separator. A constant pressure ejector model is established to evaluate the influence of fluid composition, vapor quality and other parameters on the cycle performance. Then the cycle performance is compared with the traditional ejector refrigeration cycle (ERC). It is found that COP achieves a maximum of 0.13 with mixture R245fa/R134a (0.5/0.5), and the exergy efficiency achieves a maximum of 10.53% with mixture R245fa/R134a (0.6/0.4). As the vapor quality increases from 0.1 to 0.2, the cycle COP increases from 0.08 to 0.19, the exergy efficiency increases from 7.78% to 12.49% and the area ratio decrease from 5.18 to 4.53 with mixture R245fa/R134a (0.5/0.5). The parametric analysis shows that the cycle performs better in higher vapor quality, lower generating temperature and lower condensing temperature.