An Experimental Study of Critical Heat Flux for Low Flow of Water in Vertical Round Tubes Under Low Pressure

Abstract

An experimental study has been performed on the critical heat flux (CHF) for stable low flow of water in vertical round tubes under low pressure. Experiments have been performed with a test section of diameter 0.01m (heated length = 0.9and 0.6m) under atmospheric pressure. Test results are discussed in the aspects of parametric effects of the following parameters: mass flux, flow direction, inlet subcooling, inlet throttling, heated length-to-diameter ratio and natural circulation. The test data are compared with those of the authors' previous experiments with different test sections and existing correlations.