A MATHEMATICAL MODEL OF A MICRO-COGENERATION SYSTEM COUPLED TO A HEAT PUMP FOR RESIDENTIAL APPLICATIONS: AN ENERGETIC PERFORMANCE ASSESSMENT

This paper describes a mathematical model of a micro-cogeneration system made up of an internal combustion engine, mechanically coupled to a reversible heat pump (GHP unit). The small-scale cogenerator model is based on the experimental performance maps of the engine, that have been normalized, in order to allow the model to be scaled for the simulation of a large range of plant in the very small sizes (1-10 kWel). The electricity produced by the cogenerator feeds the heat pump, which is able to provide both heating and cooling power. The natural gas fired heat pump model is integrated in a novel software platform for dynamic simulation of the whole building-HVAC system called ODESSE (Optimal DEsign Smart Energy System). ODESSE platform has been developed by the Italian National Agency for New Technologies, Energy and Environment (ENEA) using MATLAB/Simulink software, and is aimed at assessing the technical-economic feasibility of interventions for the energy improvement of existing buildings. This platform is supposed to be an interesting tool also for the analysis of performances of CHP systems in polygeneration and district-heating configuration. The GHP model, within the ODESSE platform, is employed for the simulation of the energetic performance of micro-cogeneration systems, when applied in residential air conditioning applications, such as the household energy demands of small block of family users. This research is carried out by Politecnico di Torino and ENEA (Italy) in the framework of “R&D activities of general interest for the National Electric System” funded by Ministry of Economic Development (MSE). The main results of the study are thoroughly presented in the paper.