Prediction of PF-5060 Spray Cooling Heat Transfer and Critical Heat Flux

Abstract

Spray cooling heat transfer measurements of PF-5060 on smooth flat surfaces were obtained using a microheater array operated at constant temperatures using two nozzles (hollow cone and full cone), three nozzle-to-heater standoff distances (3, 5, and 7 mm), four nozzle operating pressures (207 kPa, 345 kPa, 483 kPa, and 689 kPa), and three subcooling levels (11 °C, 21 °C, 31 °C). A separate test setup was used to measure the local normal pressures produced by the sprays. The critical heat flux was found to depend primarily on the local normal pressure and the liquid subcooling. Furthermore, the temperature at which CHF occurred was within a narrow temperature band (about ±5 °C) for smooth flat surfaces over a wide range of spray conditions. The single-phase correlation previously proposed by the authors and the CHF correlation presented in this work were then combined to predict local spray cooling curve within ±25% of the measured values in the spray impingement zone.