Modeling convective boiling flow with in-situ local vapor extraction

Graduation date: 2010The pressure drop of convective boiling flow may be reduced by extracting vapor locally since the entire generated vapor does not have to travel through the entire channel length. In this study, the theoretical model was developed to simulate a convective boiling flow through a fractal-like branching microchannel network with vapor extraction. The fractal-like branching microchannel network has a porous membrane forming one wall of the channels. Vapor extraction occurs by applying a vacuum across the membrane. Sample predictive local conditions and global results are presented and discussed. The predicted results are classified into two groups: low inlet flow rate-low heat flux and high inlet flow rate-high heat flux. The results show that to increase extracted vapor mass flow rate, either decreasing the absolute extracting pressure or increasing permeability of the porous membrane must occur. As the amount of vapor extracted increases, the reduction in pressure drop across the channel and the exit vapor quality is achieved