Experimental characterization of an Organic Rankine Cycle (ORC) for micro-scale CHP applications

Abstract

This work conducts an experimental characterization of an Organic Rankine Cycle (ORC) module along the operating conditions expected for micro Combined Heat and Power (CHP) applications. For this, a monitored test bench has been used and adapted to the planned test procedure, which consisted of varying the condensing conditions for a fixed low grade heat source. Thereby, 10 steady state points are achieved and analyzed according to thermal power input, useful heat production, gross and net electrical powers, electrical and thermal cycle efficiencies and expander effectiveness parameters. The results show the importance, for all the cited parameters, that takes to operate with a suited pressure ratio, associated with the expander built-in volume ratio, to each specific application. So, if the useful heat temperature requirements allow to operate with a moderate under-expansion in the expander, the module is optimized.