Simulation and optimization of a R744 two- temperature supermarket refrigeration system with an ejector

Abstract

In order to make R744 two-temperature supermarket refrigeration system operate effectively in countries with higher ambient temperatures such as China, a conventional booster refrigeration system was modified by adding an ejector into the system. Simulations were performed to investigate and optimize the new system under different ambient temperatures and compared with the conventional booster refrigeration system. Results showed that the compressor's work of the booster refrigeration system with an ejector can be reduced by more than 10% compared to the conventional booster refrigeration system at tamb=35oC, resulting in an increase of COP more than 11%. However, it is worse than the conventional booster refrigeration system when the ambient temperature is low. In order to solve this problem, a further improved booster refrigeration system with an ejector by adding different control strategies was proposed, which can ensure that the system operates with a high COP at all ambient temperatures.