Numerical simulations of the condensing steam-water flow


Numerical simulations of the condensing steam-water flow

Apanasevich, P.; Lucas, D.; Seidel, T.

Gas-liquid two-phase flows including heat and mass transfer across a moving interface have become increasingly important in engineering equipment and technology. In recent decades, experimental and numerical investigations of condensation heat transfer have also been of major importance in connection with the safety analysis of nuclear reactors. Some scenarios for Small Break Loss Of Coolant Accidents (SB-LOCA) lead to an Emergency Core Cooling (ECC) water injection into the cold leg of a Pressurized Water Reactor (PWR). The cold water mixes there with the hot coolant present in the primary circuit. The mixture flows to the downcomer where further mixing of fluids takes place. Such a scenario may result in high thermal loads on the Reactor Pressure Vessel (RPV) wall, while the system pressure is still high. Such a situation is known as Pressurized Thermal Shock (PTS). In context of two-phase PTS situations direct contact condensation occurring in the cold leg and downcomer is one of the most important phenomena. Improvement and validation of CFD models for two-phase stratified condensing flows require high-resolution data in both space and time for the whole domain of interest. For this purpose, the TOPFLOW DENISE experimental program has been conceived at the Helmholtz-Zentrum Dresden-Rossendorf. Its objective is to provide an experimental database for both the validation of CFD modeling of the two-phase condensing flow and to improve the understanding of the direct contact condensation phenomena involved. The paper focuses on condensation of the steam on a subcooled water interface and describes the pre-test CFD simulations of the DENISE steam/water experiments. The simulations were performed to support the definition of the experimental test matrix and the procedure of experiments.

Keywords: Direct Contact Condensation; Stratified Two-phase flow; CFD

  • Contribution to proceedings
    The 15th International Topical Meeting on Nuclear Reactor Thermal - Hydraulics (NURETH-15), 12.-17.05.2013, Pisa, Italy
    Proceedings of NURETH-15
  • Poster
    The 15th International Topical Meeting on Nuclear Reactor Thermal - Hydraulics (NURETH-15), 12.-17.05.2013, Pisa, Italy

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Publ.-Id: 18827