Steady-state pool boiling heat transfer experimental studies of horizontally-placed tubes

Abstract

In this study, the pool boiling heat transfer experimental results are obtained from horizontally-placed tubes for various materials including FeCrAl alloys, Zircaloys, Inconels and Stainless Steels. The experimental results show that FeCrAl-C26M has higher pool boiling critical heat flux (CHF) than Zircaloys while the experimental CHF values of other two FeCrAl variants, i.e., B126Y and B136Y, are lower than that of Zircaloys. Given that FeCrAl-C26M and FeCrAl-C36M are reported to have higher pool boiling CHF than the traditional claddings, those experimental results speak to that the CHF priority of FeCrAl alloys depends on the variant series of tube materials. The micro-scale surface characterization analyses clearly illustrate that three FeCrAl variants are less susceptible to surface temperature overshooting oxidization than three Zircaloy variants. In comparison with FeCrAl-C26M, Inconel 600 has the closest pool boiling CHF among four Stainless Steels and three Inconels. Experimental results of this study support that both surface hydrodynamics and solid thermal-physical properties can have influential impacts on pool boiling CHF. It is also confirmed that the sandblasted and oxidized samples can render higher CHF values than their as-received samples. Moreover, the effects of tubing wall thickness on pool boiling CHF are experimentally investigated in this study. It is found that the corresponding experimental results show that thicker tubes result in lower pool boiling CHF.