Enhancement in Active Thermal Management Efficiency of Micro/Mini-Pipes Based on Phase Change to Consider Pressure Drop

The efficient heat dissipation capacity of phase-change cooling offers a reliable solution for cooling high heat flux devices. Nevertheless, the evolution of phase-change fluid frequently encounters volatile states, resulting in considerable pressure fluctuations. This paper seeks to enhance the pipes active cooling efficiency of phase change by examining the weight ratios of pipe structural parameters on heat transfer, pressure drop, and comprehensive performance. Simulation model based on the Volume of Fluid (VOF) methodology was constructed to investigate the heat transfer and pressure reduction performance of the pipes. A comprehensive performance factor that considering both pressure drop and heat transfer characteristics was developed. The contributions of pipe structural parameters to the objective functions of pressure drop, heat transfer, and comprehensive performance are evaluated using a combination of orthogonal experiments and the Signal-to-Noise ratio (SNR) function. The accuracy of the numerical model was validated using quartz lamp thermal experiments. The findings suggest that when formulating the objective function based on comprehensive performance, the principal influencing factor for micro-pipe is wall thickness, accounting for up to 42.7 %. Conversely, for mini-pipes, the primary influencing factor is coolant flow velocity, contributing 43 %. Due to the effects related to size, the factors influencing the overall performance of micro/mini-pipes differ. They are primarily influenced by alterations in vapor volume fraction generated by phase change inside the pipeline. This study proposes an evaluation method considering multiple factor levels, furnishing crucial technical support for phase-change heat transfer technology.