A CCHP system based on ORC cogenerator and adsorption chiller experimental prototypes: Energy and economic analysis for NZEB applications

In this work, the study of a novel solar driven Combined Cooling, Heating and Power (CCHP) system is carried out. In particular, the system is composed of a 60 m flat plate solar thermal collectors field, a 10 kW photovoltaic plant, a 2 m Thermal Energy Storage (TES), a 3 kW micro-Organic Rankine Cycle (micro-ORC) prototype, a 4.4 kW thermally driven Adsorption Chiller (AC) coupled with a 6 kW auxiliary Heat Pump (HP). It has been conceived for residential applications and has been integrated with a real bioclimatic nearly zero energy building (NZEB). The building-plant system has been modelled in TRNSYS environment and studied for three Italian locations, spread along the peninsula, with three different climates, Messina, Milano and Rome. An energy, environmental and economic analysis have been carried out. The system has been assessed on hourly basis and the sensitivity analysis has demonstrated that performances are sensitive to location. In particular, the effectiveness of the system is greatly affected by solar radiation and weather condition. The CCHP system works for about 2400 h during the whole year on average with global efficiencies ranging from 32% to 42%. The plant is generally suitable for air conditioning applications in residential sector only with a government's financial support. A medium value of Pay Back Time of 6 years has been found with a medium Net Present Value of 50 kEUR. In conclusion, this study has highlighted the potential of solar driven micro-CCHP systems based on advances technologies for residential applications.