An experimental study on high pressure pure steam condensation in a PRHRS condensation heat exchanger tube of SMART

Abstract

An experimental investigation of local condensation heat transfer on high pressure pure steam was conducted in a Passive Residual Heat Removal System (PRHRS) condensation heat exchanger tube of System-integrated Modular Advanced ReacTor (SMART). SMART is a Korean type small nuclear reactor for dual purpose small scaled power generation and seawater desalination, and is an integrated pressurized water reactor. PRHRS is a system for removing residual heat of core at accident situation. The heat generated in reactor core transfer to condensation heat exchanger, so condensation heat transfer occurs in condensation heat exchanger. Thus, in this study, condensation heat transfer characteristics in a vertical tube, which is same as actual condensation heat exchanger tube, size were studied. The test section material is SUS 316L. The experiments were conducted for steam mass flux 22.47 kg/m2s and 52.87 kg/m2s to investigate the mass flux effect on heat transfer coefficient, and for steam pressure 2, 4, and 6 MPa to investigate the pressure effect on heat transfer coefficient. The obtained heat transfer coefficients increase as the steam mass flux increases or steam pressure decreases. The obtained heat transfer coefficients were compared with previous correlations: Nusselt’s (1916) theory equation, Shah’s (1974) correlation, Lee and Kim (2008) correlation. The correlations could not estimate the experimental data, but the Shah’s correlation underestimate or well estimate almost whole experimental data except for low quality ( - 0.1) region. Thus, Shah’s correlation was good for safety analysis code in conservative aspect.