Results of an experimental investigation of critical heat flux (CHF) in forced convection boiling from small heat sources to a subcooled flow are presented. Tests were conducted using a heater patch which is flush-mounted in the wall of a rectangular channel. A Nichrome patch is used which has been designed to allow variation of heated length from 0.25 mm to 0.50 mm and 0.75 mm. A platinum heater patch extends the heated length to 1.0 mm and 3.0 mm. An inert fluorocarbon liquid (FC-72) is circulated through the channel at velocities from 2.46 m/s to 8.62 m/s with pressures from 129 kPa to 274 kPa and subcooling values from 13 to 46°C. The maximum CHF over the range of parameters investigated is 170 W/cm2. This is achieved without damage to the heater. Results show how CHF increases with increasing bulk velocity and subcooling. The dependency of CHF on pressure is weak. The CHF value decreases approximately as the 0.3 power of the heating length.
|Original language||English (US)|
|Number of pages||7|
|Journal||American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD|
|State||Published - Dec 1 1989|
|Event||Porous Media, Mixture, and Multiphase Heat Transfer: Presented at the Winter Annual Meeting of the ASME - San Francisco, CA, USA|
Duration: Dec 10 1989 → Dec 15 1989