Modular micro-trigeneration system for a novel rotatory solar Fresnel collector: A design space analysis

Abstract The aim of this paper is to study a new modular micro-scale trigeneration system based on a rotary Fresnel collector, named “SunDial”, under a restricted design space. This system is based on the integration of an organic Rankine cycle with a vapor compression heat pump using miniaturized turbomachinery. Four layouts areoed to maximize the energy supply according to different heat management strategies, as requested by potential end-users. In addition, a working fluid screening is carried out which has lead to the selection of two candidates: isobutane and propane. A consistent system performance metric has been defined in order to coherently asses the configurations conceived. Different degrees of integration between the power cycle and the heat pump are analyzed. The influence of power, heating and cooling supply on the global metrics are studied for each design. Finally, an energy flow sizing is presented for a 15 kWth solar thermal input SunDial module applied to different industrial end-users. Results show that isobutane is preferable when high shares of heating and cooling are required, whereas propane leads to higher power outputs.