Experimental Thermal-hydraulic Analyis of a Super-critical CO₂ Natural Circulation Loop

Abstract

Experimental thermal-hydraulic studies of a rectangular supercritical CO2 natural circulation loop with a horizontal heated channel were conducted at different steady-state conditions. These included three different system pressures and three different inlet temperatures, with different inlet and outlet valve openings. Detailed information of friction-factor and local head loss coefficients were produced. Comparison shows that for the available experimental set-up, computed frictional pressure-drops fall within 1-1.2 of the Blasius formula. Moreover, flow oscillations were observed frequently when the CO2outlet temperature was higher than the pseudo-critical temperature on the negative slope part of the mass flow-rate versus power curve