Investigations on a test bench for integrated ORC-FC Micro-CHP energy systems

Micro-CHP (Combined Heat and Power) energy systems are potentially suitable for residential and tertiary utilities, typically characterized by low-grade heat demand and limited electric-to-thermal energy demand ratio values. Different innovative and under development CHP technologies are currently investigated in small scale units, but a standard has not been identified till now. Moreover, depending on the load request, the produced electricity can be used, stored in electric accumulator or in the external net, or integrated with other external sources. Contextually, the available heat can be used, accumulated inside the system or dissipated. The actual convenience of small size CHP systems depends on the demand profiles and the operation management logic. A test facility is being developed, at the University of Bologna, for the experimental characterization of the cogenerative performance of small scale hybrid power systems, composed of micro-CHP systems of different technologies: a Micro Rankine Cycles (MRC), a Proton Exchange Membrane (PEM) Fuel Cells (FC), a battery and a heat recovery subsystem. The test set-up is also integrated with an external load simulator, in order to generate variable load profiles. This report describes the main characteristics of the implemented test bench, the selection procedure of the adopted micro-CHP unit and expected performance. Further the development of a calculation code able to simulate the performance of the considered systems will be described. This calculation code has been applied to design the components of the test bench. More in details, in this paper the sizing of the electrical energy storage system, and of the thermal and H2 storage tanks will be presented and discussed.