Effect of Geometry on the Performance of Co2 Gas Cooler/Condenser and its associated

As a natural working fluid, CO2 is increasingly being used in refrigeration systems in which an air cooled CO2 gas cooler or condenser is employed on the system to reject heat to the ambient. Depending on the application and design, the CO2 refrigeration system can be a single-stage or multi-stage. Whatever the design, the CO2 gas cooler or condenser plays an important role in maximising system performance. To understand and facilitate the effect of CO2 gas cooler or condenser on refrigeration system performance and controls, two CO2 finned-tube gas coolers/condensers with different geometric designs were built, instrumented, connected to an existing CO2 booster refrigeration system and tested extensively. Models of the finned-tube CO2 gas coolers/condensers have been developed and validated with the measurements. The models are used to investigate the effect of geometric parameters on the performance of the CO2 heat exchangers and associated refrigeration system.The authors would like to acknowledge the support received from GEA Searle and Research Councils UK (RCUK) for this research project