Effects of Pressure and a Microporous Coating on HFC-245fa Pool Boiling Heat Transfer

A study was conducted to experimentally characterize the pool boiling performance of hydrofluorocarbon HFC-245fa at pressures ranging from 0.15 MPa to 1.1 MPa (reduced pressure range: 0.04–0.31). Pool boiling experiments were conducted using horizontally oriented 1-cm2 heated surfaces to quantify the effects of pressure and a microporous-enhanced coating on heat transfer coefficients and critical heat flux (CHF) values. Results showed that the coating enhanced heat transfer coefficients and CHF by 430% and 50%, respectively. The boiling heat transfer performance of HFC-245fa was then compared with the boiling performance of HFC-134a and hydrofluoroolefin HFO-1234yf.