Correlations for Saturated Critical Heat Flux in Microchannels

Experimental results of the saturated-flow boiling critical heat flux (CHF) in microchannels for both multi- and single-channel configurations were obtained from the literature. The collected database contains 629 data points, covering 5 refrigerants, nitrogen, and water, for a wide range of operational conditions, and different micro-channel dimensions. The whole database was analyzed by using four empirical correlations to verify their respective accuracies. However, none of the existing correlations could predict the entire database precisely. A saturated CHF correlation was proposed by using boiling number, length-to-diameter ratio, and exit quality. The new correlation can predict the overall micro-channel database accurately on the whole. It predicts almost 97.0% of the non-aqueous data (except R12 data points located in the macro-scale region) and 94.0% of the water data within the ± 30% error band.