CHF comparison of an attached-fin hypervapotron and porous-coated channels

Critical heat flux experiments were undertaken on two medium-scale, bare copper, mock-ups of the ITER vertical target. One was an attached-fin hypervapotron made of CuNiBe and manufactured by Boeing Company, and the other contained two round porous-coated channels made of CuCrZr and manufactured by the Efremov Institute. All the experiments were performed in the EB-1200 electron beam facility at Sandia and used ITER relevant flow conditions of 100/spl deg/C inlet subcooling, 4 MPa, 10 m/s water. Both the flat ITER nominal, and the highly peaked, ITER transient, heat flux profiles were used, For both mock-ups, we maintained a near constant exit subcooling by fixing the total beam power and decreasing the heated length from 360 mm to 150 mm and 140 mm, respectively. Results are compared to finite element model predictions and to data obtained on swirl tubes and helical wire mock-ups tested under similar conditions. Local CHF was detected at 21.3 MW/m/sup 2/ for the hypervapotron and 24.5 MW/m/sup 2/ for the porous coated -up mock when subjected to the flat heat flux profile. New Global CHF/burnout data are presented for the attached-fin hypervapotron for better comparison to global CHF values obtained on swirl tapes and helical wires.