关键词: 流动沸腾, 液氮, 两相流, 传热, 汽化

Abstract: This paper presents an experimental investigation on the heat transfer characteristics of liquid nitrogen flow boiling in a vertical tube. The variations of wall temperature, fluid temperature, quality, and heat transfer coefficient in the flow direction were analyzed. The effect of heat flux, inlet pressure and mass flux on the flow boiling heat transfer coefficients was examined. Four correlations by Chen, Klimenko, Shah, and Liu-Winterton were adopted to predict the flow boiling heat transfer coefficient. The relative errors in different ranges of heat transfer coefficients were calculated and analyzed to evaluate the correlations under the experimental conditions. The predicted results show that the results calculated with the four correlations are generally lower than the experimental data. The Klimenko correlations are more adaptable under the whole experimental conditions.

Key words: flow boiling, liquid nitrogen, two-phase flow, heat transfer, vaporization