Article ID: 2019.011
The development of the molten core cooling system without the electric power based on a lesson of Fukushima daiichi nuclear power plant accident is carried out over the world. Many researchers reported that the nano-fluid had the capability of critical heat flux enhancement and the nano-fluid could be applied to cool the molten core in combination with natural circulation flow. The purpose of this study is to obtain the better understanding of the flow characteristics of multiphase flow, which mix air and nano-fluid (water and TiO2 nano particle) under natural circulation condition. Experiments were carried out at atmospheric pressure and room temperature. Seven kinds of vertical test section are used; three circular tubes, two rectangular channels and two tapered tubes. The following conclusions can be obtained. (1) As the two-phase flow, the multiphase fluid was found to have stable natural circulation without problems. (2) There was approximately no great difference between the flow characteristics (void fraction, flow rate and pressure drop) of the natural circulation of multiphase flow and the air-water two phase flow.
