A general correlation for evaporative heat transfer in micro/mini-channels

Experimental results of the saturated-flow boiling heat transfer in micro/mini-channels for both multi- and single-channel configurations were obtained from the literature. The collected database contains more than 3700 data points, covering a wide range of working fluids, operational conditions, and different micro-channel dimensions. The whole database was analyzed by using various existing correlations to verify their respective accuracies. However, none of the existing correlations could predict the data sets precisely. Using the boiling number, Bond number and Reynolds number, a general correlation for evaporative heat transfer in micro/mini-channels was established. In addition, the Bond number in predicting heat-transfer coefficients can be used as a criterion to classify a flow path as a micro-channel or as a conventional macro-channel.