Experimental study of thermal-hydraulic performance of a printed circuit heat exchanger with straight channels

Abstract Experiments have been performed on a printed circuit heat exchanger (PCHE) with straight channels to examine its thermal-hydraulics performance. Heat transfer between carbon dioxide at a supercritical pressure (sCO2) in the primary side and cooling water in counter flow direction at the secondary side has been analyzed. The results showed an enhancement in convective heat transfer when sCO2 was cooled from the gas-like zone to the pseudo-critical zone. And it shows a minimum value of LMTD in the pseudo-critical zone, which implies a minimum temperature difference there between sCO2 and the cooling water. Correlations for friction factor and heat transfer coefficient have been developed using the experimental data. The new developed friction factor correlation predicts 100% of the data within ±20% error band, and the new developed heat transfer correlation predicts 92.4% of the data within ±30% error band. These correlations have been applied in an analytical code for designing PCHE. An assessment of the code against various experimental cases illustrates good agreements between predictions and experimental bulk-fluid temperature along the axis, as well as the predicted and observed locations of the pinch point.