Pressure Effect on Nucleate Boiling and Critical Heat Flux of R1233zd(E) on a Smooth Copper Surface

Abstract

This study examines the impact of pressure on the nucleate pool boiling performance of the sustainable refrigerant R1233zd(E), with a focus on the Heat Transfer Coefficient (HTC) and Critical Heat Flux (CHF). Experiments on a smooth copper surface with an average roughness (Ra) of 0.03 μm, under pressures of 1 to 2.5 bar reveal that both HTC and CHF improve with increasing pressure due to greater nucleation site density, smaller bubble sizes, and higher detachment frequencies. However, the HTC enhancement with pressure is not constant in the range studied. Comparison with existing HTC correlations and CHF models shows partial agreement, highlighting the need for correlations based on a bank of data covering a wider range of fluids. The results facilitate the use of R1233zd(E) in energy-efficient thermal systems and sustainable heat transfer technologies.