Environment-friendly refrigeration packs for Indian supermarkets: experimental investigation of energy performance of a multiejector-driven R744 integrated compressor rack.

An integrated CO2 refrigeration facility is designed for hot climate conditions to improve the basic knowledge of the CO2 refrigeration in India, especially in the supermarket sector. The operational modes can be adapted to simulate different applications as well as the gas cooler outlet temperature can be regulated to simulate various ambient conditions. For Southern India, a parallel compression configuration with ejectors for expansion work recovery is the most efficient mode (mode 4). It can deliver freezing, refrigeration and air conditioning loads, and has a heat reclaim option. The different operation configurations help to understand the behavior of CO2 refrigeration for a wide range of applications as well as reveal the respective influences between components. A first test phase running mode 4 for an ambient temperature of 46°C and various receiver pressures in a range of 44 bar - 50bar, proves the feasibility of R744 transcritical systems as a non-HFC based alternative to HCFC-22 in retail applications in countries with high ambient temperature. The CO2 refrigeration test facility is a preparation and demonstration site for a full-scale replacement of existing commercial refrigeration installations in India.