抄録
In a natural circulation loop, flow instability, such as density wave oscillation, occurs under a certain operating condition, while the influence of flow oscillation on the heat transfer is not well understood so far. Experiment was conducted by using a natural circulation loop of liquid nitrogen with test tubes of dimensions of 3.0mm/5.0mm I.D., and 900mm heated length. It was indicated that the heat transfer correlation of Schrock-Grossman was in good agreement with experimental results in the saturated boiling region even under oscillatory flow condition, and that the correlation of Roko was in good agreement with the experimental results of post-dryout heat transfer even under oscillatory flow condition. On the other hand, the CHF was well predicted using the lumped-parameter model, taking account of the circulation rate, oscillation frequency and amplitude of mass flux in the natural circulation loop.
