Experimental Drop-In Replacement of HFC-245fa by HCFO-1224yd(Z), A Low-GWP Working Fluid Candidate for Low-Temperature Organic Rankine Cycles

摘要

The Organic Rankine Cycle (ORC) has gained prominence due to the urgent need to preserve the environment.This technology contributes to reduce the carbon footprint through the generation of electric power fromrenewable energy sources and low-grade waste heat. HFC-245fa is commonly used as working fluid in lowtemperatureORCs, despite its zero Ozone Depletion Potential, its Global Warming Potential (GWP) is 858.With increasing restrictions on greenhouse gases, the price of those fluids with high GWP has risen. In thiscontext, HCFO-1224yd(Z) has been recently presented as potential candidate for HFC-245fa replacement.Therefore, this work aims to experimentally test the suitability of using this low-GWP candidate in an existinglow-temperature and small-scale HFC-254fa designed ORC. The drop-in replacement tests show similarbehaviour between HFC-245fa and HCFO-1224yd(Z) and although HFC-245fa provides higher expanderpower output, net cycle efficiencies are similar, and several adjustments can be introduced to compensate thelower electrical output.