THE EXPERIMENTAL STUDY ON STRATIFICATION AND TRANSPORT OF HYDROGEN IN THE CONTAINMENT WITH LIGHT NON-CONDENSABLE GAS

This study was based on the passive containment thermal hydraulic facility, which locating in Beijing Key Laboratory of Passive Nuclear Power Safety and Technology, North China Electric Power University, Beijing. The platform was built in the year of 2010, Pro. Niue has carried out a series of studies about the thermal stratification and concentration stratification for air and water vapour and achieved remarkable results. In this paper, the experimental test is divided into two consecutive stages: phase A and phase B. Phase A is the injection phase of steam, however, phase B is divided into three steps, include hydrogen injection, no injection, opening the external spray, to study the stratification and transport of hydrogen (replaced with helium) in a cylindrical steel container which has ellipsoid dome, and also discussing the change of hydrogen concentration near the wall over time. Except for this, the distribution of hydrogen during the third step is also emphasized. For the transport of gas, it has not given the direct result of measuring in this paper, but it gave the analysis of transport which is based on the hydrogen concentration at different stages, different location of the containment over the time. It can be found that: 1) during the stages of hydrogen injection, no injection, the stratification is obvious, but, the helium concentration in the dome space is uniform, and the transport of the gas is mainly affected by the thermal buoyancy and jet, 2) near the wall-area, the trend of droplet entrainment is obvious, 3) during the stage of opening the external spray, the mixture of gas is intensified and the stratification is weakened.