Design and Performance Analysis on CO<sub>2</sub> Combined System in Supermarket

Abstract

This paper reports a combined space cooling, space heating, water heating and food refrigeration system (named CO2 combined system) in supermarket. This system using CO2 as the working fluid consists of a two-stage CO2 transcritical cycle used for food refrigeration, a single-stage CO2 transcritical cycle for space cooling in summer and space heating in winter. The waste heat emitted from the CO2 gas cooling in food refrigeration cycle and space cooling and space heating cycles is recovered by heat recover exchanger and is used to provide hot water for space heating and for general usage, such as the catering, the washing and the toilet facilities in the supermarket. So this CO2 combined system improves the coefficient of performance, decreases the energy consumption as well as reduces the heat pollution. Moreover, this CO2 combined system is compared with typical conventional supermarket technology, the results show that the energy consumption of CO2 combined system is reduced largely and energy efficiency is increased obviously. It can be concluded that the CO2 combined system has a good future for protecting environment and saving energy.