DNB heat flux in forced convection of liquid hydrogen for a wire set in central axis of vertically mounted flow channel

[摘要] Liquid hydrogen has excellent physical properties, high latent heat and low viscosity of liquid, as a coolant for superconductors like MgB2. The knowledge of Departure from Nucleate Boiling (DNB) heat flux of liquid hydrogen is necessary for designing and cooling analysis of high critical temperature superconducting devices. In this paper, DNB heat fluxes of liquid hydrogen were measured under saturated and subcooled conditions at absolute pressures of 400, 700 and 1100 kPa for various flow velocities. Two wire test heaters made by Pt-Co alloy with the length of 200 mm and the diameter of 0.7 mm were used. And these round heaters were set in central axis of a flow channel made of Fiber Reinforced Plastic (FRP) with inner diameters of 8 mm and 12 mm. These test bodies were vertically mounted and liquid hydrogen flowed upward through the channel. From these experimental values, the correlations of DNB heat flux under saturated and subcooled conditions are presented in this paper.

[发布机构] Department of Energy Science and Technology, Kyoto University, Kyoto, Japan^1;Facility for Rare Isotope Beams, Michigan State University, MI, United States^2;Institute of Space and Astronautical Science, JAXA, Kanagawa, Japan^3

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Absolute pressure;Cooling analysis;Departure from nucleate boiling;Experimental values;Fiber reinforced plastic(FRP);High critical temperature;Inner diameters;Liquid hydrogens