Experimental Study on Low-velocity Flow Boiling Heat Transfer in a 3×3 Rod Bundle

Taking deionized water as the working medium, experimental studies were conducted on flow boiling heater transfer in a 3×3 rod bundle at an inlet temperature of 80-100 ℃, a mass flow rate of 0-100 kg/(m²·s), and an inlet pressure of 0.1 MPa, so as to analyze the effects of mass flow rate and heat flux on the flow boiling heat-transfer coefficient, and to investigate the heat-transfer characteristics in various sub-channels. Four correlations were adopted to predict the flow boiling heat-transfer coefficient, including Liu-Winterton, Kandlikar, Gungor-Winterton and Chen, etc., and subsequently their prediction results were compared with experimental data, which were simultaneously evaluated using three statistic indicators. Results show that the predicted values of Liu-Winterton, Kandlikar, and Chen correlation are relatively lower than the experimental data, in which the error of Chen correlation is the highest, while Gungor-Winterton correlation is the most accurate one among all the four correlations.