Experimental Study of Two Types of Pressure Nozzles in Spray Cooling

In this study, two types of pressure nozzles including a pressure swirl nozzle and a jet-swirl nozzle were tested in an open loop spray cooling platform. In particular, the pressure swirl nozzle is a typical commercial pressure swirl nozzle that is supplied by Danfoss and the jet-swirl nozzle is in-house fabricated. The flow rate of the in-house nozzle is about 60% of the commercial nozzle. The heat transfer results show that although the flow rate of the in-house nozzle is much lower, its heat transfer performance is competitive with that of the commercial nozzle, especially in the high temperature regime. By increasing the pressure drop, the heat transfer performance is enhanced. While by increasing the spray height, the heat transfer performance is weakened probably due to the reduced impact energy of the spray droplets. The results suggests the superiority of the jet-swirl nozzle in spray cooling applications and further study is encouraged to explore the heat transfer characteristics of jet-swirl nozzles in future.