CO2 chillers for industrial applications: a theoretical study.

EDF (Electricity of France) needs high capacity chillers for its own nuclear plants, as well as for its customers (e.g. food processing or chemistry factories). Manufacturers are looking for reliable and sustainable solutions. They are waiting for high capacity CO2 chillers with good efficiencies. EDF and Le Cnam have conducted a theoretical study, calculating the EER, SEER and TEWI of different architectures of CO2 chillers, for different condensing conditions. When possible, heat exchangers and compressors manufacturers’ real efficiencies have been used. Calculations demonstrated that a CO2 transcritical or subcritical cycle including an expansion turbine is the most efficient. In Eurovent conditions, this cycle does not reach the minimum EER required for class A but is close to it, so it means that it may be interesting to carry on the study. But the SEER of this cycle is better than the R134a basic one.