Heat transfer characteristics of subcooled water in a hypervapotron under high mass fluxes and high heat fluxes

• Published in: International journal of heat and mass transfer 2019-02, Vol.129, p.580-590
• Main Authors: Zhu, Ge, Bi, Qincheng, Yan, Jianguo, Wang, Teng, Zhao, Jinle
• Format: Article
• Language: English
• Subjects: Boiling; CHF; Correlation; Fusion; Heat flux; Heat transfer; Heat transfer coefficients; High heat flux; Hypervapotron; ITER; Parameters; Reactors; Side heating; Subcooled flow boiling; Tubes
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2018.09.102

•An electrically heated method was used to simulate one-side heating conditions.•The effects of the parameters on the heat transfer coefficients have been discussed in detail.•A serious of correlations of subcooled flow boiling were assessed with the experimental results.•The experimental CHF data were discussed and used to assess subcooled CHF correlations for smooth tubes. In order to investigate the heat transfer characteristics of hypervatron in the divertor dome of the International Thermonuclear Experimental Reactor (ITER), the off-center electrically heating method was used simulate the one-side heating condition in the engineering application. The heat transfer experiments of subcooled water were carried out in a vertically upward hypervapotron under the system parameters as follows: system pressure P = 2.7, 3.2, 3.7 MPa, mass flux G = 2000–5000 kg·m−2·s−1, and equivalent one-side radiating heat flux qe = 2–5 MW·m−2. The effects of parameters on heat transfer were discussed in detail. The results show that the heat transfer coefficient h is significantly affected by G in the single phase (SP) region; the h is synthetically influenced by P, G, q in the partially boiling (PB) region; the h is only affected by q in the fully developed boiling (FDB) region. The experimental data were compared with the typical correlations in single phase region and subcooled boiling region, respectively. The results show that the Dittus-Boelter correlation and the modified Shah correlation have good agreement with the experimental data. The typical CHF correlations for smooth tubes were assessed by the CHF data, the results indicate that experimental Bocr are overpredicted by most CHF correlations, so it can be speculated that the hypervapotron can obtain higher CHF values than smooth tubes.