High Performance Microchannel Heat Sink with Hybrid Micro/Nano Structured Mesh

Description

Enhancing energy efficiency and reducing CO2 emission is crucial for the sustainable development of the world. The promotion of electric vehicles is one of the important measures to meet the goal of reducing carbon intensity, such as in China or Hong Kong, as electric or hybrid vehicles demonstrate high-energy efficiency and potential for low CO2 emission. Thermal management of power electronic inverter module, such as the Insulated Gate Bipolar Transistors (IGBT), is one of the technology challenges for further development of electric vehicles. An IGBT may produce a very high heat intensity, while it must be kept below a relatively low temperature to warrant its function. Such a high demand in heat intensity with a relatively low temperature limit requires efficient liquid/vapor phase-change cooling with rationally engineered structures.The proposed study will develop a high performance microchannel heat sink with hybrid micro/nano structured mesh on both bottom and sidewalls and active feed of liquid from a manifold at demand-based flow rate. In the heat sink, intensive thin-film evaporation/boiling heat transfer will take place for the cooling of electronics with very high heat intensity. Specifically, a twodimensional manifold provides uniform liquid distribution to the porous mesh in each channel with a demand-based flow rate to remove the heat imposed through thin-liquid-film evaporation/boiling. To further enhance the liquid wicking ability, robust and multiscale micro/nano features will be fabricated on the porous mesh with chemical coating followed by another sintering process. This microchannel heat sink with hybrid micro/nanostructured mesh will be promising to demonstrate highly efficient thin-film evaporation/boiling performance due to the enhanced capillary liquid flow. This well-designed heat sink may reach an unprecedented critical heat flux with a relatively low superheat to meet the cooling requirement of electronics with very high heat intensity, such as the next generation inverter module in an electric vehicle.The present study will explore the thin-liquid-film evaporation/boiling heat transfer mechanisms in the microchannel heat sink with novel hybrid micro/nano structured mesh. Furthermore, the heat transfer coefficient, critical heat flux, and evaporation/boiling visualization as a function of liquid flow rate for the heat sink developed will be acquired. The results of the present study may promote the development of electric vehicles or other electronics with high heat dissipation rate.