Technical-economic feasibility of CHP systems in large hospitals through the Energy Hub method: The case of Cagliari AOB

Multi-energy systems satisfy different energy uses of a building such as space heating, space cooling, DHW, etc. by using different energy converters and energy sources simultaneously. These systems, if properly designed and operated, have high efficiency in the production of energy. This paper presents a method based on the Energy Hub model for the energy and economic analysis of a large hospital complex placed in Sardinia (Italy). The Energy Hub model allows dynamic simulations results and experimental data to be coupled. First of all, the model was calibrated according to real data and information obtained during an energy audit carried out by the University of Cagliari in collaboration with the Brotzu Hospital staff. Then, since cogeneration is recognised as one of the most effective ways to efficiently convert energy, the integration of a CHP system (internal combustion engine), within the multi-energy system of the hospital, was studied. The results obtained are useful to identify benefits that might be obtained by the CHP system, depending on its regulation and on the economic variables. The presented model represents a valuable tool to evaluate possible energy and economic savings and to design and to optimise every kind of multi-energy systems of a generic building.