EXPERIENCE WITH EJECTOR WORK RECOVERY AND AUXILIARY COMPRESSORS IN CO_2 REFRIGERATION SYSTEMS. TECHNOLOGICAL ASPECTS AND APPLICATION PERSPECTIVES

摘要

A recent development of CO_2 booster commercial refrigeration systems, based on the adoption of ejectors forliquid pumping and suction vapour pre-compression in an economized cycle, has demonstrated to be a viableoption to overcome the main issue associated with the use of CO_2 in warm ambient conditions, thuspromoting the diffusion of CO_2 in Southern Europe.At least 20 systems using ejectors are in operation at the moment, with different layouts. Some of themincorporate both ejectors and auxiliary compressors. Data from the field are available to support expectedperformances; as a matter of fact, the adopted solution is gaining popularity.This paper summarises the experience acquired during the development of these innovations, also focusingon technological aspects, presents some results from the field and faces the issue of moving towards asimplified design. Simplification and standardisation of the high-efficiency CO_2 solution are consideredessential to successfully spread the proposal to countries where synthetic refrigerants are nowadays the firstchoice, also for economic reasons.