Numerical simulation of critical heat flux of flow boiling under overload

Abstract In this paper, the numerical simulation of boiling heat transfer of two-phase flow under overload is described in detail, including the selection of grid division and calculation format, the determination method of CHF is discussed in detail, the VOF multiphase flow model is selected for the calculation, and the surface tension characteristics of distilled water are fully considered. After discussing the simulation results, the phase distribution characteristics of the boiling flow in the rectangular channel are obtained, and the effects of overload, mass inlet temperature, and heating orientation on the CHF are analyzed in turn. The results show that: the overload significantly increases the CHF of the boiling flow, which is similar to that of the experimental results; the effect of the mass inlet temperature on the critical heat flow is very small, which is different from that of the experimental results, but is in line with the prediction of the previous work. Different from the experimental results, but in line with the prediction of previous authors, the oversized overload will increase the flow boiling CHF, which is of some reference significance for the safe operation of engineering design.