Parameters Affecting Critical Heat Flux Of Nanofluids: Heater Size, Pressure Orientation And Anti-freeze Addition

Abstract

This research aims at investigating the effect, heater size, pressure, heater orientation and effect of anti-freeze addition on critical heat flux of nanofluids which have shown large potentials as coolants for high power generating uses. Nanofluids have shown about ~180 - 200% enhancement in the critical heat flux values. The effect of heater size employing three different sized heaters yielded about ~180% enhancement over pure water. The effect of pressure on critical heat flux investigated by testing nanofluids at three pressures showed ~240% increase in critical heat flux. Surface orientation effect on critical heat flux carried out for a 2 × 2 cm heater at five orientations revealed about ~120% enhancement at 150°. Two commercially used antifreezes, ethylene glycol and propylene glycol were used to study the effect of anti-freeze addition to nanofluids. Alumina -water nanofluid of 0.025 g/L concentration mixed with the antifreezes at five compositions by volume showed a maximum enhancement of about ~120% for ethylene glycol and ~70% for propylene glycol.