Numerical Studies of a Hybrid Cycle for Power Production and Cooling
Abstract
This work aims at studying and developing a thermodynamic heat recovery cycle for the combined production of cold energy and low power electricity (5 kW of cold, 1 kW of electricity) using water/ammonia as working fluid. The target temperature range is low enough (80 to 160 °C) to adapt not only to industrial heat recovery applications, but also to heat networks and non-concentrated solar thermal energy. Thermodynamic modeling of the cycle was carried out and a parallel architecture was proposed, in which the refrigerant vapor at the output of the generator can be used to feed the expander (production of electricity) and/or the condensation-expansion-evaporation part (production of cold). For accurate prediction of the power production, a semi-empirical model of a scroll-type expander was developed based on experimental testing of an organic Rankine cycle (ORC). The numerical data were analyzed in order to identify the key parameters influencing the performance of the present hybrid cycle.