Numerical simulation of pool boiling with special heated surfaces

In present work, numerical simulation of the pool boiling at normal environment pressure is performed. Heated surfaces with different geometries, including the plain heated surface and the modified heated surfaces with 36 hemispheres in different orientations, are both investigated. The reliability and accuracy of the present numerical method is verified by comparing the present result with that of the previous experimental one. Then, the relationship between the heat flux (q) and wall superheat (ΔT) is obtained. Moreover, the critical heat flux (CHF) of different surface is obtained as well. It is found that the vessel with modified heated surface has a better heat transfer performance compared to that of plain heated surface. Furthermore, the modified heated surface with downward facing hemispheres has the best heat transfer performance and the lowest critical heat flux (CHF) among the present three heated surfaces, which results from the increasing buoyancy component along the curved surface and the excessive crowded hemispheres at the heated surface, as well as the rough release of vapor bubbles under the condition of higher heat flux.