Experimental investigations on turbulent heat transfer of carbon dioxide in a helically coiled tube

Abstract

Experimental investigations on turbulent heat transfer of carbon dioxide in a helically coiled tube were performed under constant wall heat flux conditions. A computational program was compiled in a helical coordinate system to calculate the inner wall temperatures based on the directly measured outer wall temperatures by thermocouples. It was found that the wall temperatures increased with the increasing heat flux and the decreasing mass flux, while the heat transfer coefficients increased with the increasing heat flux and mass flux. The circumferential temperature and heat transfer coefficient distributions for a fixed cross section displayed the non-uniform character. Generally, the outer side had a relatively lower temperature and higher heat transfer coefficient than the inner side due to the secondary flow induced by the centrifugal force.

Heat transfer of supercritical pressure water in helical tubes

“…Yang et al (2021) used the RNG k-ε turbulent model with an enhanced wall function to investigate the mechanisms of deterioration and oscillation of the inner wall temperature during SCW cooling in horizontal tubes with sections of various non-circular shapes. Huang et al (2018) studied the HTCs of SCW and CO 2 in a helical tube using a numerical calculation model, and discovered that the SST k-ω turbulent model agreed well with the experimental results of Wang et al (2014), who demonstrated that the maximum wall temperature was at a certain angle in the circumferential direction under the effects of centrifugal force and buoyancy in the helical tube. Wang et al (2015) studied the applicability of various turbulence models for heat transfer calculations in helical tubes using the experimental data from convective heat transfer of supercritical CO 2 in helical tubes.…”