Experimental tests and modelization of a domestic-scale ORC (Organic Rankine Cycle)

The work deals with the realization, the experimental testing and the modelization of a small-size ORC (Organic Rankine Cycle) prototype. The main components of the circuit, filled with the refrigerant R245fa, are a plate condenser, an inverter-driven diaphragm pump, an electric boiler and a scroll expander. The latter is a hermetic device, derived from a commercial HVAC compressor, and expected to deliver a power of about 1.5 kW. Some performance parameters of the whole cycle and of the plant components have been investigated by means of a series of experimental tests, whose results are discussed in the paper. The registered working parameters and efficiencies are comparable with those expected from previous studies and reported in literature, even if the system is not yet optimized. These results are the basis for the numerical modelization of the cycle, realized with the simulation software LMS Imagine.Lab AMESim®, capable to simulate systems also in transient conditions. This model, calibrated on the basis of the experimental measurements, has revealed a good skill in predicting the main working parameters of the system, so it will be used to achieve a better knowledge of the physical system and to choose a more suitable control strategy for the prototype.