Transverse heat transfer coefficient in the dual channel ITER TF CICCs. Part III: Direct method of assessment

• Transverse heat and mass transfer in ITER TF CICC is studied.
• Direct analysis based on mass and energy balance equations is performed.
• Heat transfer coefficient between bundle and central channel is determined.
• Enhancement of heat transfer in heated cable segment is observed.
• Correlations for heat transfer coefficients are discussed and a new one is proposed.

The data resulting from the thermal-hydraulic test of the ITER TF CICC are used to determine the flow partition and the overall effective heat transfer coefficient (hBC) between bundle and central channel in a direct way, i.e. by analysis of the heat transfer between both flow channels, based on the mass and energy balance equations and the readings of thermometers located inside the cable. In cases without a local heat source in the considered cable segment the obtained hBC values were consistent with those obtained in earlier studies by analysis of experimental data using indirect methods. It was also observed that the transverse heat transfer was strongly enhanced in a cable segment heated from outside. This phenomenon results from the mass transfer from the bundle region to the central channel. The experimental hBC data obtained for the case without a heat source in the considered segment were also compared with those calculated using various heat transfer correlations.