Contact

Dr. Dirk Lucas

Head Computational Fluid Dynamics
d.lucasAthzdr.de
Phone: +49 351 260 2047

Condensing flow

Promising results for adiabatic flows encouraged to extent the HZDR baseline model for other conditions, for example, with phase change, chemical reaction, as well as material systems other than air-water , e. g. Argon-GaInSn. In the present work, it is applied for condensing steam-water flows inside a large vertical pipe.

Figure 1 shows the simulated steam distribution during its condensation in sub-cooled water under different pressure p, inlet sub-cooling degree ΔT as well as orifice size rorifice.

Saturated steam condensing in sub-cooled water
Figure 1: Saturated steam condensing in sub-cooled water (a) p=10bar, ΔT=3.9K, rorifice=1mm; (b) p=10bar, ΔT=5.0K, rorifice=1mm; (c) p=20bar, ΔT=3.7K, rorifice=1mm; (d) p=20bar, ΔT=6.0K, rorifice=1mm; (e) p=20bar, ΔT=6.0K, rorifice=4mm; (f) p=40bar, ΔT=5.0K, rorifice=1mm

Modelling of interphase heat transfer coefficient is another active research topic. Figure 2 show the evolution of steam volume fraction along the pipe obtained by using the Tomiyam and the Ranz-Marshall correlations.

Wirkung von Zwischenphasen-Wärmeübertragungskorrelationen auf die Evolution des Dampfvolumenanteils entlang des Rohres
Figure 2: Effect of interphase heat transfer correlations on the evolution of steam volume fraction along the pipe, symbol: experiment, red line: Tomiyama correlation, green line: Ranz-Marshall correlation, (a) p=10bar, ΔT=3.9K, rorifice=1mm; (b) p=10bar, ΔT=5.0K, rorifice=1mm; (c) p=20bar, ΔT=6.0K, rorifice=1mm

The poly-disperse iMUSIG-approach is used to capture the change of Sauter mean diameter of steam bubbles at condensation.

Evolution of Sauter mean diameter along the pipe
Figure 3: Evolution of Sauter mean diameter along the pipe, symbol: experiment, red line: calculation, (a) p=10bar, ΔT=3.9K, rorifice=1mm; (b) p=10bar, ΔT=5.0K, rorifice=1mm; (c) p=20bar, ΔT=6.0K, rorifice=1mm

Selected publications

  • Liao, Y., Lucas, D.
    Poly-disperse simulation of condensing steam-water flow inside a large vertical pipe.
    International Journal of Thermal Sciences, 104, 194-207
  • Liao, Y., et al.
    Application of new closure models for bubble coalescence and breakup to steam-water vertical pipe flow.
    Nucl. Eng. Des., 279, 126-136
  • Liao, Y. et al.
    Interfacial heat transfer models for flashing flows: a review.
    13th international conference Multiphase Flow in Industrial Plant, Sept.17-19, Genova, Italy
  • Liao, Y., et al.
    New coalescence and breakup kernels for air-water and steam-water pipe flows.
    5th Population Balance Modeling Conference (PBM2013), Bangalore, Indian, Sept. 11-13
  • Lucas, D.; Frank, T.; Lifante, C.; Zwart, P.; Burns, A.
    Extension of the inhomogeneous MUSIG model for bubble condensation.
    Nucl. Eng. Des., 24, 4359-4367
  • Krepper, E.; Beyer, M.; Lucas, D.; Schmidtke, M.
    A population balance approach considering heat and mass transfer e experiments and CFD simulations.
    Nucl. Eng. Des., 241, 2889-2897
  • Lucas, D.; Prasser, H.-M.
    Steam bubble condensation in sub-cooled water in case of co-current vertical pipe flow.
    Nucl. Eng. Des., 237, 497-508