Modelling and calibration of multi-energy system in a chocolate industry

The possibility to reduce energy consumption is becoming an important issue to encourage and promoting energy efficiency also in the food industry. For this reason, it is important to study multi- energy systems where different energy sources are used to produce hot water for space heating and domestic uses. The case study presented in this paper is referred to a chocolate factory. Domestic hot water is available through a storage tank installed in the boiler room. The tank is loaded by solar collectors and by a gas back-up boiler. The cold aqueduct water, used for filling the storage tank, is first preheated recovering waste heat from the condensers of the chillers units. This system was equipped with flow meters and temperature probes. Recorded data were used to calibrate the numerical model developed using TRNSYS software. The thermal model was developed to analyse from energetic point of view the described heating system. The numerical model and the monitoring system constitute a useful decision tools for assessing potential energy savings because simulation results and real data monitored can be compared in order to establish energy and economic savings that may be achieved.