Intensification of heat transfer at propane pool boiling on single horizontal tubes.

A set of experiments was carried out with propane pool boiling on the smooth and porous surfaces of horizontal tubes in different saturation pressure ranges, temperature intervals -10 to +40 °C, and heat flux ranges 100 to 100,000 watt/m2. Three modes of heat transfer were determined: free convection, a transitional mode and developed boiling. Remarkable heat transfer enhancement of up to 2.5-3 times was observed for propane pool boiling or porous horizontal tubes, in comparison with that on smooth and small roughness tubes over the heat flux intervals tested.