Measurement and Prediction of Dryout Front Movement During Rapid Depressurisation

摘要

As part of the study of safety of water cooled reactors, a series of steady state and transient depressurisation dryout tests were performed using a 3.658 m long, 12.7 mm ID electrically heated tube at pressures of up to 7 MNm exp -2 m and mass velocities up to 2200 kgm exp -2 s exp -1 . During the transient experiments the dryout front allowed to propagate down the heated section and its progress was monitored by a series of thermocouples fitted to the outside wall of the tube. Inlet conditions of temperature and flow remained reasonably steady throughout the transient. The data from both steady state and transient tests were compared with predictions from an annular flow model and a correlation. Both the model and the correlation were able to predict the general form of the dryout front movement, although the model gave the more accurate predictions. Steady state calculation techniques seem to be applicable to this type of transient, and the accuracy of the results is largely determined by the steady state prediction accuracy at the same fluid conditions. (Atomindex citation 15:070146)