[3G01-07] Boiling, Condensation, Heat Transfer

[3G04] Condensation Heat Transfer for Downward Flows of Superheated Steam-Air Mixture in a Circular Pipe

*Michio Murase¹, Yoichi Utanohara¹, Raito Goda², Shigeo Hosokawa³, Akio Tomiyama² (1. Institute of Nuclear Safety System, Inc., 2. Kobe University, 3. Kansai University)

Keywords:Vertical pipe, Steam-air mixture, Superheated steam, Condensation heat transfer, Heat transfer coefficient

Temperature distributions for downward flows of superheated steam-air mixture were measured in a vertical circular pipe with diameter of 49.5 mm, and heat fluxes q and condensation heat transfer coefficients hc were evaluated. The obtained hc,exp agreed well with hc,cal calculated from a correlation based on the diffusion layer model for saturated steam-air mixture. This showed that hc can be calculated as condensation from the saturated conditions near the condensation surface even in the superheated bulk conditions.