Thermal-Hydraulic Characteristics of Microchannel Heat Exchanger and Its Application to Solar Gas Turbines

Abstract

Incorporating “integral method” proposed here, a set of empirical correlations of local heat transfer coefficient and pressure loss coefficient are newly derived based on experiments using microchannel heat exchanger (MCHE) with supercritical carbon dioxide as heating medium and water as coolant. They are expressed in dimensionless forms of polynomial of Reynolds number and Prandtl number. The same correlation of Nusselt number is found applicable to both fluids and its value is almost two times larger than Dittus Boelter correlation. It was also shown that the above form is applicable to a wide range of geometry with the values of constants changed. Accuracy of both correlations is confirmed within 5% errors for MCHE with S-shaped fins in the range of pressures 9∼12.5MPa and temperatures 280∼390K. Based on the correlations, sizes of heat exchangers are evaluated contained in gas turbine cycle with super critical carbon dioxide as a working fluid applicable to solar power.

Process Intensification for Compact and Micro Heat Exchangers through Innovative Technologies: A Review

“…171 Nikitin et al 172 and Ngo et al 173 experimentally investigated the advantages of the S-shaped fin configuration in the recuperators for a CO 2 gas turbine and CO 2 heat pump system, respectively. Utamura and Nikitin 10,174 made a specific comparison between a recuperator 12 and a hot water supplier, 167 both with S-shaped fins. Good agreement (within an experimental error of 5%) between the numerical and experimental results was reported.…”