Heat Transfer Performance of EVAPORON-3 Developed for an Enlarged Heat Transfer Surface of Divertor

• Published in: Plasma and Fusion Research 2017/04/17, Vol.12, pp.1405015-1405015
• Main Authors: TAKAI, Kio, YUKI, Kazuhisa, SAGARA, Akio
• Format: Article
• Language: English
• Subjects: boiling; Discharge; divertor; evaporation; Flow velocity; Heat flux; Heat transfer; high heat flux removal; Porous materials; Porous media; Pressure loss; Thermal conductivity; Vapors; water cooling; Water flow
• ISSN: 1880-6821; 1880-6821
• DOI: 10.1585/pfr.12.1405015

In this study, we newly propose two types of water-cooled divertor devices called EVAPORON-3 using high thermal conductivity porous media that could be applicable especially to an enlarged heat transfer surface such as the divertor plate. Each device has a liquid-vapor separating plate (LVS plate) on the top surface of the porous medium. The LSV plate of the Type-1 device has 9 inlet holes for liquid supply and 12 outlet holes for vapor discharge against a heat transfer surface with the diameter of 30 mm. On the other hand, the LSV plate of the Type-2 device has just one liquid inlet hole at the center of the plate and 12 outlet holes for the vapor discharge. The diameter of each hole is 2.6 mm. The introduced porous medium is a particles-packed bed with the particle diameter of 1.0 mm. In order to reduce pressure loss of the liquid and vapor flows in the porous medium, two layers of the particle are set between the heat transfer surface and the LSV plate. The thickness of the porous bed is 1.82 mm. The result showed that each device enabled a high heat removal of over 5 MW/m2 and, in particular, the Type-2 device succeeded in the heat flux removal of approximately 11 MW/m2 at the water flow rate of 2 L/min, although the pressure loss increased by decreasing the number of the inlet holes.