Heat recovery performance of an integrated CO2 commercial refrigeration system with dedicated mechanical subcooler

CO2 as a refrigerant can meet the strictest requirements in terms of safety and global warming. All-in-one plants, supplying refrigeration, heating and air conditioning simultaneously with carbon dioxide as working fluid are becoming more and more common. However, in mild and hot climates CO2 refrigeration plants need to implement strategies to provide an acceptable energy efficiency. Among the several possible solutions, dedicated mechanical subcooling is one of the most promising technologies. Nevertheless, the on-field monitoring of real plants which deploy these strategies is still scarce. The aim of this work is to present the results of monitoring a commercial refrigeration plant which uses CO2 as refrigerant evaluating its heat recovery ability, and developing and validating a numerical model to predict the performance of the plant at various control logics and configurations.