Vapor separation application in minichannel heat sink flow boiling heat transfer

The large amount of vapor accumulation in minichannel is a crucial factor restraining the flow boiling performances of minichannel heat sink. Addressing this issue, we propose a novel idea to design minichannel heat sink based on the concept of vapor separation. The novel minichannel heat sink has dedicated vapor channels in addition to liquid channels. Micro-pore (diameter around 20 mu m) porous copper is employed as ribs, a critical component for achieving vapor separation. Vapor separation minichannel heat sink broadens the vapor discharge pathway, and the outlet is not the only pathway to discharge vapor out of vapor separation minichannel. Moreover, externally regulated vapor channel pressure can adjust the amount of separated vapor to actively adapt to the heat transfer requirements for different heat flux working conditions. Flow boiling experiment is conducted to investigate the thermal and hydrodynamic performances by employing water as the working fluid. Vapor separation significantly improves minichannel flow boiling performances. The heat transfer coefficients still improve around 1.3 times even for high heat flux conditions; system pressure and total pressure drop also significantly decrease, with a maximum 59.4 % reduction in system pressure and 25.5 % in total pressure drop obtained. This novel idea opens a new way to eliminate the accumulation of vapor in minichannel and improve thermal and hydrodynamic performances for minichannel heat sink.