A study compares HFC-245fa to two HFOs, HCFO-1233zd-E and HFO-1336mzz-Z, as a working fluid for ORCs (Organic Rankine Cycle).
HCFO-1233zd-E could reach up to 10.6% higher net cycle efficiencies, and HFO-1336mzz-Z up to 17 % than HFC-245fa over the range of cycle conditions examined.
Larger turbine sizes would however be required : about 7.5%10.2% with HCFO-1233zd-E and about 30.9%41.5% with HFO-1336mzz-Z.
The net cycle efficiency increases and the required turbine size decreases relative to HFC-245fa for HCFO-1233zd-E and for HFO-1336mzz-Z at higher evaporating and condensing temperatures.
Source: Science Direct