Speaker
Hui Bao
(School of Nuclear Science and Technology)
Description
Square channel is widely used in the conceptual design of water cooled blanket of fusion reactor for cooling and providing appropriate inner temperature field for tritium breeding. Thermal hydraulic design of blanket directly determines the heat transfer efficiency and safety characteristics of fusion reactor. Therefore, thermal-hydraulic characteristics of square channel should be investigated. The appearance of subcooled boiling greatly affects flow instability of coolant channels in blanket and safety characteristics of fusion reactor. Onset of nucleate boiling(ONB) is the cut-off point of single-phase flow and two-phase flow, and the flow and heat transfer characteristics will change a lot after ONB. For 8×8 mm22 square channel in blanket, the experimental study of subcooled boiling has been conducted. Experimental results showed that onset of nucleate boiling was strongly affected by system pressure and heat flux, while the effect of inlet supercooling temperature of the experimental channel was not very significant. Comparing the experimental results with Bergles-Rohsenow correlation and other correlations, it can be found that the correlations which had been developed by other researchers could not represent subcooled boiling characteristics in square channel. Therefore, a new empirical experimental correlation was developed on the foundation of experimental data. The new correlation can predict the relationship between the wall superheat and heat flux at ONB with the maximum relative error of 35%.
Co-authors
Changhong Peng
(School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, China)
Hui Bao
(School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, China)
Yun Guo
(School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, China)
