Dryout Analysis of the WSGHWR (Winfrith Steam-Generating, Heavy-Water Reactor) Cluster Loop Post-Dryout Experiments of September 1976

摘要

A series of tests were made in the Winfrith SGHWR in-pile Loop to investigate post-dryout heat transfer. The results for the onset of dryout have been analyzed and are described; the post-dryout analysis will be the subject of another paper. With the exception of 8 anomalous data points, the onset of dryout was well correlated by the Bowring mixed flow cluster correlation at the two system pressures of 2.0 and 5.9 MPa. Also, at both pressures, the in-pile dryout power was 4% higher than that found in very similar out-of-pile tests. This small discrepancy may be accounted for by the marginal difference in the two tests. The 8 anomalous data points were part of a set of 12 runs, all at comparable conditions of low flowrate, low power at a pressure of 5.9 MPa. Four of the runs were consistent with the rest of the tests but in the other 8, premature dryout occurred at a channel power some 15% less than that of the 4 ''normal'' runs. The effect may be explained in terms of hydrodynamic flow oscillations, possibly triggered by ''soft-inlet'' conditions.