Heat Transfer Characteristics of Evaporative Spray Cooling In a Closed Loop 2002-01-3198
A closed loop spray cooling test setup is established for the cooling of high heat flux heat sources. Eight miniature nozzles (in a multi-nozzle plate) are used to generate a spray array targeting at a 1×2 cm2 cooling surface. FC-87, FC-72, methanol and water are used as the working fluids. Thermal performance data for the multi-nozzle spray cooling in the confined and closed system are obtained at various operating temperatures, nozzle pressure drops (from 0.69 bar to 3.10 bar) and heat fluxes. It is exhibited that the spray cooler can reach the critical heat fluxes of 90 W/cm2 with fluorocarbon fluids and 490 W/cm2 with methanol. For water, the critical heat flux is higher than 500 W/cm2. The air purposely introduced in the spray cooling system with FC-72 fluid has a significant influence on heat transfer characteristics of the spray over the cooling surface.