Abstract：According to volume of fluid model and user defined function, the numerical simulation was performed to predict the flow boiling of water in 0.2 mm×20.0 mm microchannel with V grooves. The effects of the ratio of groove depth to width h/R and the groove number n on critical heat flux of flow boiling were analyzed. The results show that under the working conditions with inlet water temperature Tin of 369.00 K, velocity v of 0.2 m·s-1 and a certain number of grooves n of 30, the critical heat flux(CHF) in microchannels is different by varying h/R with R of 0.02 mm. Setting h/R with different values of 1, 2, 3 and 4, the critical heat fluxes are 400, 375, 500 and 450 kW·m-2, respectively, and the highest CHF is 500 kW·m-2 for h/R of 3. When h/R is given as 3, the critical heat flux is increased with the increasing of groove number. While n values are taken as 30, 90 and 150, the critical heat fluxes are 500, 525, 575 kW·m-2, respectively. Under a certain condition, suitable groove structure with h/R of 3 and much more V grooves on heating wall can improve the critical heat flux in microchannel, which is helpful to maintain the reliability of flow boiling heat transfer.
2018, Vol. 39 
