Study of a Solar Booster Assisted Ejector Refrigeration System With R134a

A parametric study for a booster assisted ejector refrigeration system in steady state is carried out employing Lu’s ejector model in transition regime. The range of generator and condenser temperatures is considered for a solar powered system. Conceiving the ejector geometry, through the area ratio φ and the main throat area A*, and the system behavior, through the energy efficiency COP_s, the exergy efficiency ε_s and energy ratio Er, it was found that their extreme values, lowest for A* and highest for the remainder, are reached at the highest generator temperature, T_GE, and booster discharge pressure, p_DIS, with the lowest condenser temperature, T_CO, for the considered evaporator temperature, T_EV, of −10°C. In regard to the ejector behavior, its maximum efficiency value, η_EJ, is reached for the highest T_GE and the lowest T_CO for an intermediate p_DIS. If T_CO is increased, the maximum η_EJ value is achieved at a higher p_DIS. In spite of that the maximum η_EJ value is not reached at the highest p_DIS, its influence is not reflected in system behavior because U always increases and its maximum value agrees with theory. The most important system and ejector parameters are presented as a reference.