Convective heat transfer from molten salt droplets in a direct contact heat exchanger

• Published in: Heat and mass transfer Vol. 46; no. 8-9; pp. 999 - 1012
• Main Authors: Jaber, O., Naterer, G. F., Dincer, I.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2010; Springer
• Subjects: Alternative fuels. Production and utilization; Applied sciences; Energy; Engineering; Engineering Thermodynamics; Exact sciences and technology; Fuels; Heat and Mass Transfer; Hydrogen; Industrial Chemistry/Chemical Engineering; Original; Thermodynamics; Drag Coefficient; Heat Transfer; CuCl; Heat Exchanger; Drag Force; Thermochemical cycle; Hydrogen; Heat exchanger; Numerical simulation; Droplet; Modeling; Convection; Hydrogen production; Heat recovery; Heat transfer; Molten salt; Solidification
• ISSN: 0947-7411; 1432-1181
• DOI: 10.1007/s00231-010-0630-6

This paper presents a new predictive model of droplet flow and heat transfer from molten salt droplets in a direct contact heat exchanger. The process is designed to recover heat from molten CuCl in a thermochemical copper–chlorine (Cu–Cl) cycle of hydrogen production. This heat recovery occurs through the physical interaction between high temperature CuCl droplets and air. Convective heat transfer between droplets and air is analyzed in a counter-current spray flow heat exchanger. Numerical results for the variations of temperature, velocity and heat transfer rate are presented for two cases of CuCl flow. The optimal dimensions of the heat exchanger are found to be a diameter of 0.13 m, with a height of 0.6 and 0.8 m, for 1 and 0.5 mm droplet diameters, respectively. Additional results are presented and discussed for the heat transfer effectiveness and droplet solidification during heat recovery from the molten CuCl droplets.