Experimental investigation of subcooled void growth for upflow and downflow at low velocities and low pressure

• Main Author: Bibeau, Eric Louis
• Language: English
• Published: University of British Columbia 2010
• Subjects: Heat > Transmission; Nuclear reactors > Design and construction
• Online Access: http://hdl.handle.net/2429/28365

A two-phase experimental loop was designed and built to simulate the operating conditions of the SLOWPOKE reactor. Void growth was measured for both upflow and downflow for velocities between 0.07 to 0.46 m/s and at a pressure of 155 kPa. The buoyancy effect causes the Onset of Significant Void, OSV, to occur at higher subcooling for downflow than for upflow. This effect is maximum close to the bubble rise velocity (0.23 m/s) and decreases at higher velocities. The results indicate that bubble detachment is not the only critical parameter affecting OSV. The OSV correlations from the literature did not predict the experimental results well. Investigation of the heat transfer mechanisms indicates that fully developed sub cooled boiling occurs prior to OSV. === Applied Science, Faculty of === Mechanical Engineering, Department of === Graduate