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 (such as Organic Rankine Cycles and Proton Exchange Membrane Fuel Cells), 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.
1. Introduction
Large scale power production and transmission with high power density network is currently the predominant solution to cover the distributed users power demand in many industrialized countries. Remarkable performance values could be achieved with further improvements of such large scale power plants in the near future [1]. Nevertheless, micro-CHP (Combined Heat and Power) systems are under investigation in the framework of a distributed generation approach, allowing for a reduction in the network losses and for the fulfillment of both thermal and electricity demand of local consumers [2]. Micro-CHP systems have natural potential suitability for different civil, tertiary and industrial applications, such as residential buildings, hospitals, supermarkets, sporting centers, etc., where a significant thermal demand is associated to the user electricity demand, reducing primary energy consumption and also environmental impact [3]. A large market potential for Micro-CHP has been identified since more than ten years ago, as highlighted for example by Dentice d’Accadia et al. in [4].
Conclusion
A complex multi-source micro-CHP system has been implemented in our laboratory. The system is available and it will be further improved, as described here, for different test campaigns The management system is under development, in order to define the optimum operating logic. A preliminary performance investigation has been carried out and limited results here shown will be extended in the near future.
