In CO2 refrigerating system, one of the most effective techniques for the improvement of energy
efficiency is subcooling the fluid at the exit of the gas cooler. This can be achieved by taking
advantage of cooling capacity supplied by HVAC chillers or dedicated mechanical refrigeration units.
Furthermore, in the presence of subcooling the settings of the CO2 system can be modified in order
to further reduce the energy use of the plant. In this paper, the effect of Dedicated Mechanical
Subcooling on the performance of a CO2 booster system is investigated, and compared to a plant
scheme where subcooling is performed via the HVAC, at two different climate conditions. The effect
of optimisation of the gas cooler pressure is also investigated, and shows to be effective especially
at hot climate conditions.
