Numerical investigation on the thermal performance of a new cooling unit for refrigerated transport using CO2 as the working fluid.

Refrigerated trucks are an essential link in the cold chain, since they are in charge of guaranteeing the delivery to the market of perishable freights in safe and high-quality conditions. The choice of the refrigerant in transport refrigeration is undergoing a though revision, as an indirect consequence of the phase down of synthetic refrigerants imposed by the F-gas regulation. In order to explore natural refrigerant options, a refrigerated unit with CO2 as working fluid was designed, with the possibility of using a new configuration with a two-phase ejector in place of an expansion valve. This paper presents a modelling approach to predict the system performance identified by the expected COP curves at different ambient conditions.