Experimental characterization of heat transfer in non-boiling spray cooling with two nozzles

Heat transfer in a non-boiling spray cooling system with de-ionized water as the working fluid is experimentally investigated. An open-loop test system with two full-cone spray nozzles used to generate water droplets to a heated surface is established for the cooling of high-power devices. The effects of the liquid volume flow rate, the nozzle-to-surface distance and the liquid inlet temperature on the heat transfer are scrutinized. It is found that the non-boiling spray cooling system can remove high heat flux from a small surface while maintaining the surface at desirable low temperature. Increasing the liquid volume flow rate or reducing the liquid inlet temperature increases significantly the heat transfer coefficient. There exists an optimal nozzle-to-surface distance under which the heat transfer coefficient is maximized. It is also found that adding a surfactant to the working fluid with an appropriate concentration will further improve the heat transfer.