Modeling and Simulation of Phase Change Heat Transfer in Spray Cooling

Spray cooling has attracted widespread attention due to its advantages in high heat flux removal and high heat transfer coefficient. Simulation method for spray cooling was studied in this paper to contribute to the design and application of spray cooling. A new simulation method for phase change heat transfer in spray cooling was suggested. It was based on the four heat transfer mechanisms from the literature, including film convection, pool boiling, secondary-bubble boiling, and high frequency mechanism of secondary-bubbles. Monte Carlo method was adopted to describe the impaction of spray droplets on film with different distributions of diameter and velocity and the form of secondary bubbles. Bubble growth rate was modelled with semi-analytical solutions of bubbles in liquid. Bubble evolvement was modelled with the puncture of bubbles by droplets, the collapse of bubbles due to film contaction, and the merge between bubbles. Both wall film convection and bubble phase-change heat transfer were considered, and then spray cooling was simulated. Spray cooling experiment was implemented. The agreement between simulation results and experimental data suggested that the new method could simulate spray cooling quite well. Additionally two groups of factors affecting the prediction accuracy were analyzed.