Abstract

Despite the extensive use of CO 2 in food retail refrigeration units, it has never been implemented, tested or simulated in Cuba. This work aims to evaluate by simulation a Booster and Parallel compression system in twelve Cuban cities using two different semi-empirical approaches to model the compressors and the gas cooler/ condenser. The compressors are modeled with a semi-empirical model and the gas cooler/condenser is modeled with a lumped model based on the epsilon-NTU method, discretizing the gas cooler in a one-zone model and the condenser into a three zones model. According to the results, the Booster and Parallel average consumptions are 640 MWh and 540 MWh, respectively. Both systems are less efficient than the conventional R404A refrigeration system. The lower capital costs of transcritical systems make them cost-effective solutions compared to the conventional system. Moreover, the Parallel system is an economically feasible alternative compared to the Booster one. The payback period of the Booster system is 10 to 12 years by considering the environmental and operating costs savings respect the Direct eXpansion System, while for the Parallel system the payback period is between 8 and 8.5 years. Both transcritical systems are excellent environmental alternatives to the R404A conventional system.