MODELLING INTEGRATED HVAC AND REFRIGERATION SYSTEMS IN A SUPERMARKET

摘要

Decision makers in the supermarket chains ask with ever increasing strength for a comparison betweenrndifferent HVAC and refrigeration plant solutions, not only in terms of investment costs, but also of energyrnneeds. The option of heat recovery from the refrigeration plant in favour of the HVAC system for spacernheating is being more and more considered, thus requiring the simulation of a complex system where controlrnstrategies play a crucial role. This topic is of great importance also in the view of the reduction of CO_2rnemissions, because supermarkets are intensive users of energy.rnIn this paper the preliminary results of a comprehensive model of the HVAC and refrigeration systems in arnsupermarket are presented. This model is developed in the framework of the EU project CommONEnergy,rnand is based on the Trnsys platform.rnA cascade refrigeration system to supply various display cabinets and walk-in coolers is considered forrnrefrigeration, while a Water Loop Heat Pump (WLHP) system is considered for HVAC. Heat recovery isrnperformed by collecting heat from the condensers of the refrigeration systems in favour of the WLHP in therncold season. The effect of a water reservoir is evaluated, as heat storage device for the water loop. Therncapabilities of such a plant scheme are discussed in the view of energy savings for the whole supermarket.rnTwo locations, representative of as many different European climatic zones, are considered. Optimal valuesrnof the activation temperatures for heat recovery, auxiliary heating system and cooling towers are discusses asrnwell as the most convenient size of the reservoirs in order to minimize the primary energy consumption.