Use of biporous wicks to remove high heat fluxes

Three monoporous wicks with average powder diameters 60 mu m, 300 mu m, and 600 mu m and five biporous wicks with average cluster (mu m) to powder (mu m) ratios and wick thickness (mm) 600/60/4, 300/60/4, 600/40/1, 300/60/1, and 300/40/1 were tested with degassed distilled water. Dryout values for monoporous wicks were: 223 W/cm(2) at 3 7 degrees C superheat (60 mu m), 209 W/cm(2) at 31 degrees C superheat (600 gm), and 222 W/cm(2) at 73 degrees C superheat (300 mu m). Dryout values for biporous wicks were 236.5 W/cm(2) at 45 degrees C superheat (300/40/1), 160 W/cm(2) at 18 degrees C superheat (600/40/1), and 150 W/cm(2) at 32.5 degrees C superheat (300/60/1). Dryout of thick wicks was not seen. They were able to remove 202 W/cm(2) at 81 degrees C superheat (300/60/4), and 494 W/cm(2) at 128 degrees C superheat (600/60/4). The 300/40/1 wick showed the highest heat transfer coefficient, 10.4 W/cm(2) K, at 180 W/cm(2). For high heat flux removal is most desired 600/60/4 wick, which can continuously remove heat at almost constant heat transfer coefficient, 4.2 W/cm(2) K, without seeing a dryout. All wicks were tested at a partial pressure of the water vapor 0.1 atm. (c) 2006 Elsevier Ltd. All rights reserved.