Study Of The Contact Interaction Between Coolant Water And High Temperature Molten Metal

The fuel-coolant interaction (FCI) may occur when the molten corecontacts coolant water during sever accidents. Rapid heat transfer leads toquick evaporation and the pressure loads it produces may endanger thesurrounding structures and cause radiation leak. Since the FCI process iscomplicated, the mechanism of it and the consequence it brings are still notvery clear. Further study is still necessary.To observe the interaction of coolant and molten metal, a smallexperimental facility is designed and established at first. The interaction ofwater and melt tin is recorded with high speed camera system after waterdrop falls into a melt tin pool. The water temperature, melt temperature andthe water drop velocity have been varied to study the effect of them on theinteraction process. To simulate the direct liquid-liquid contact process afterthe vapor film between water and melt tin collapses, a calculation code isdeveloped in the second half. The variation of convective heat transfercoefficient with time and the distributions of pressure, temperature and velocity in the coolant are analyzed.It shows that the variation of water drop temperature has no significanteffect on the interaction process since the water drop is too small. Theviolence of the interaction increases with increasing melt temperature at firstand then decreases with increasing melt temperature. The violence of theinteraction increases with increasing water drop velocity. The interface goestowards the liquid with greater density when the direct liquid-liquid contactoccurs, so the interface is unstable because of Rayleigh-Taylor instability. Inthe direct contact process, the convective heat transfer coefficient remains ata high level and the variation of melt tin temperature from250oC to350oChas no significant effect on it.