Abstract:
Enhanced pool boiling critical heat fluxes (CHF) at reduced wall superheat on nanostructured
substrates are reported. Nanostructured surfaces were realized using a low temperature process,
microreactor-assisted-nanomaterial-deposition. Using this technique we deposited ZnO nanostructures
on Al and Cu substrates. We observed pool boiling CHF of 82.5 W/cm2 with water as
fluid for ZnO on Al versus a CHF of 23.2 W/cm2 on bare Al surface with a wall superheat
reduction of 25-38 C. These CHF values on ZnO surfaces correspond to a heat transfer
coefficient of ~ 23000 W/m2K. We discuss our data and compare the behavior with conventional
boiling theory.
