Numerical Study on Direct Contact Condensation Phenomenon of Saturated Steam

A Direct Contact Condensation (DCC) of steam at low mass flux and the pressure oscillation induced by steam condensation was investigated and analyzed. Simulations using lumped-parameter codes have been considered as one option to model suppression pools. Pttikangas et al. simulated the water hammer due to a steam bubble collapse by using 2Daxisymmetric CFD (Computational Fluid Dynamics). Yadigaroglu and Lakehal suggested that the Volume Of Fluid methodology (VOF) simulation for the injection of steam/air-mixture from a vertical blowdown pipe into a water pool can exchange the rates for the DCC heat and mass transfer. This study is to evaluate condensation phenomena using the VOF methodology with condensation physics continuum and conjugated heat transfer in the chugging flow region. The Direct Contact Condensation was analyzed on the steam injected into the suppression pool. As a result of the influence of the pin holes in the suppression pool, it is possible to prevent the chugging flow under the low steam flow rate in the blowdown pipe, but the pressure in the pipe becomes lower than the atmospheric pressure, and the condensation occurs only in the blowdown pipe.