Research on the Heat Transfer Characteristics of Air-Atomized Water Spray Cooling by Experiment and Inverse Heat Conduction Method

The heat transfer characteristics of air-atomized water spray cooling on the hot metallic surface are presented and discussed in this paper. The controlling parameters mainly investigated are air pressure and spray height. The effects of these parameters on the important thermal characteristics such as interfacial heat transfer coefficient, cooling rate, and wetting layer evolution attained by experiment and inverse heat conduction method. The value of interfacial heat transfer coefficient is proportional to the air pressure and inversely proportional to the spray height. As the air pressure is 0.2 MPa, and the spray height is 40 mm, the maximum cooling rate is 85.08 ℃/s. There is no film boiling stage under this condition. At the spray height is 80 mm, and air pressure is 0.3 MPa, the maximum cooling rate is 62.6 ℃/s. In addition, transition boiling and nucleate boiling always exist, but their retention time is different under different conditions. The temperature-dependent interfacial heat transfer mechanism of air-atomized water spray cooling is explored according to the thermal characteristics and photographs taken by the high-speed camera. The results show that air pressure and spray height both have an influence on the interfacial heat transfer.