ENERGY SAVINGS POTENTIAL USING THE THERMAL INERTIA OF A LOW TEMPERATURE STORAGE

摘要

50% of the energy consumed in food cold chain are for chilling, freezing and storage steps. For cold storagernfacilities, refrigeration is the main source of energy consumption with an average of 50 kWh/m3/year. Arnpossible strategy to reduce their energy consumption is to take advantage of the variation of performance ofrnthe refrigeration systems during a day due to external and internal temperature variations. Electricity cost canrnalso widely change during a day, depending on the local production. This strategy can be based on additionalrnstorage capacities to delay the refrigeration running period, but also on the use of the thermal inertiarnprovided by the storage warehouse itself and the products stored. An experimental test has been performed inrna frozen warehouse storage facility to evaluate the potential energy savings of such a strategy. Using coupledrnmodels of the building, products and refrigeration system, using weather forecasts and products fluxrnstatistics, a predictive control algorithm was developed and applied to determine periodically the optimal setpointsrnof the storage warehouse. Technical implementation of the control system is presented. Energyrnsavings potential and impact on products of the temperature fluctuations are also discussed.