Development of low-pressure-loss steam separator with design by analysis and test (I) validation of analysis method and design of low-pressure-loss steam separator

The purpose of this study is to develop a steam separator for BWR with low pressure loss by CFD and a scale model test. The swirler is the key component for the separation performance and pressure loss. Therefore, we have focused on the improvement of the swirler and tried to improve the swirler geometry to reduce the swirler pressure loss while maintaining the separation performance. This study consists of two stages. In the first stage, we measure pressure loss and water discharge ratio using the 1/2.22-scale test under BWR operating pressure, and then validate the CFD method by comparison with the scale test results. In the second stage, we improve the swirler geometry by the survey of some geometry factors using CFD. We predict that the inlet and outlet pressure losses of the swirler are dominant in the separator. By improving the geometry at the inlet and outlet of the swirler, we show from the results of CFD and a scale test that the improved swirler can reduce pressure loss by about 50% compared with the conventional swirler.