Cost efficient optimization based supervisory controller for supermarket subsystems with heat recovery

In this paper, we present a simple modelling approach for a thermal system, which consists of heating, ventilation, air conditioning system (HVAC) and a vapour compression cycle (VCC) system, with one loop heat recovery. In addition a simple model for water tank is presented, in which the reclaimed heat is stored and/or which can be used for heating purposes of the building. We present a dynamic optimization algorithm that according to the received price signal, occupancy information and ambient temperature minimizes the operation cost of the whole system and distributes set points to local controllers of supermarkets subsystems. We find that when reliable information about the high price period is available, it is profitable to use the refrigeration system to generate heat during the low price period, store it and use it to substitute the conventional heater during the high price period.