Analysis of an advanced R744 cycle and its impact on green house gas emissions by climate zone.

Transport (mobile) refrigeration applications offer designers unique application and hardware challenges in selecting new refrigerants. These systems are mobile and have to work efficiently and reliably in a wide range climatic conditions to include adapting to changing climate zone conditions as they move in country, in region and globally. A previous paper presented at the Gustav Lorentzen Conference by Finckh et al. (2016) provided a new evaluation methodology utilizing global climate zone data and a transport refrigeration products efficiency versus ambient profile to understand the impacts on the life cycle climate greenhouse gas (GHG) emission by climate zone. This paper presents a manufacturers analysis of testing of an advanced two stage compression R744 refrigeration unit. A simple thermodynamic model was developed to model this unit’s performance and to handle R744 transcritical operation and various cycle improvements. The R744 test unit performance data was used to calibrate the model and to validate various cycle improvements. The GHG emissions profiles of various R744 duty cycles and future potential cycle improvements will be provided and compared to R452A by climate zone using the methodology provide by Finckh.