Integration of trigeneration in an indirect cascade refrigeration system in supermarkets

This article presents an energy and economic analysis of a trigeneration configuration for supermarket applications. The energy system in a supermarket is relatively complex, because it includes lighting, air conditioning, cabinets, refrigeration system, etc. A trigeneration system could be used to simultaneously satisfy heating, refrigeration and electricity demands in supermarkets. More specifically, this article studies the integration of a trigeneration system and an indirect refrigeration cascade compression system in a supermarket in Barcelona. The trigeneration system consists of a cogeneration engine and an ammonia/water absorption chiller unit. The results of simulating energy usage, life cycle costs and CO2 emissions have been compared with a conventional indirect refrigeration cascade compression system for the supermarket studied. Several trigeneration configurations have been studied. They all show a payback time of less than 6 years but the profitability of the investment depends strongly on the ratio between the prices of natural gas and electricity. This study shows that this novel trigeneration system is economically feasible and environmentally more viable than conventional supermarket systems.