Parallel CO2 refrigeration system compared to state-ofthe-art solution in supermarket application

Abstract: This thesis compares the performance of two trans-critical CO2 refrigeration systems, the state-of-the-art booster system and the standard parallel system. The main goal is to quantify the efficiency difference between these two systems. By using computer assisted calculations both systems are modelled, then energy results are obtained. Different configurations for the parallel solution are considered. Adding direct expansion sub-cooling or using indirect sub-cooling, gives a significant improvement in the performance of the system. Also, a heat recovery control system is considered to operate when a heat load is demanded. The calculations indicate that standard parallel system with the assumptions given, become a more efficient solution with a COP of 6,8 and 3 for the MT level and LT level respectively. This translate in energy saving of 9% and 7,6% when the heat recovery control system is used in comparison with the state-of-the-art booster system.