Season change significantly influences the cooling requirement and electricity consumption of supermarket refrigeration systems. Monthly total equivalent warming impact (TEWI) and system performance parameters (COP, discharge gas temperature-pressure, work of compression etc.) have been assessed for a typical supermarket refrigeration system of Tokyo, Japan. A medium temperature (–7 °C, 200 kW) and a low temperature (–25 °C, 50 kW) cooling load have been considered for the assessment. The results indicate that the monthly lowest TEWI is found in February and highest is in July for single cycle refrigeration system. The possibility of cascading for low temperature cooling load is also considered for smooth operation and longer lifetime. TEWI of past twenty years is presented to give an overview of how much global warming is originated by a mid-size supermarket.
Keywords: climate, COP, GWP, Japan, R404A, R410A, supermarket, TEWI.