NEW SUPERCRITICAL HFC-134A ORC SYSTEM WITH INCREASED ENERGY EFFICIENCY

A new two-stage supercritical HFC-134a ORC (Organic Rankine Cycle) technology has been demonstrated to be 15-20 % more efficient than commonly installed single stage subcritical turbines.

The supercritical system was first tried in a 500 kW (electrical production) test turbine, and, after confirmation of its expected energy improvement, scaled up to a 10 MW geothermal power unit, transforming heat into electrical power from hot brine at 152 °C.

The working fluid HFC-134a did not decompose during the turbine operation and, being non flammable, was appreciated for simplifying the authorization and design phases, compared to hydrocarbon fluids.

Source: ENEL