Abstract:
The void fraction at different heights in the annular channel of moderator cell mockup was measured with a differential pressure transducer. The tests proved that the ratio of surface tension to density of liquid phase is the main factor that determines the physical properties on void fraction. The larger the ratio, the smaller the void fraction. The ratio of surface tension to density of Freon 113 is lower than that of liquid hydrogen. Therefore, Freon 113 can be used as working fluid to study the void fraction in the hydrogen two-phase thermo-siphon loop in the cold neutron source (CNS) of China Advanced Research Reactor (CARR)), and the results are conservative.