Technical assessment of thermal-hydraulics for high heat flux fusion components

A technical assessment of three possible thermal-hydraulic high heat flux (HHF) heat removal techniques which will result in adequate heat removal from fusion components with minimum penalty is presented. The heat removal alternatives discussed are: (1) subcooled flow boiling (SFB) with water; (2) high velocity helium gas convection (HGC); and (3) liquid metal (LM) heat transfer in the presence of a transverse magnetic field (TM). Each heat removal technique is examined for a case study applicable to near-term fusion components such as limiters and divertors. The results can be used, along with other fusion component performance constraints, to determine the research and development direction of generic problems such as HHF removal from fusion components in both near-term or existing fusion reactors and long-term or proposed reactors. Specifically, comparisons are made for the selected case study of heat removal from a 1.5 m long, 1.0 cm diameter (inside) coolant channel which is subjected to a uniform steady-state heat flux of 0.5 kW/cm(2). The results show that SFB has the greatest heat removal capability, with the lowest coolant channel wall temperature and pumping power, followed by HGC and LMTM.