Abstract
In order to simulate the seismic vibration effect on the Boiling Water Reactor (BWR), vibration experiments of subcooled boiling two-phase flow in an annulus have been performed and visualized. The annulus test section was scaled down from a fuel assembly sub-channel of a BWR and attached to a vibration beam driven by an eccentric cam operating at low frequency to simulate seismic vibration effects on two-phase flow. The inner and outer diameters of the annulus test section are 19.1 and 38.1mm respectively, and the height of the test section is 2.75m. Subcooled boiling two-phase flow with a mass flux of 499.96 kg/m2s and inlet subcooling of 5.5 to 6.4oC were performed with eccentric cam rotation speed up to 270RPM and maximum displacement 19mm (d=±9.5mm). Vibration acceleration and area-averaged void fraction are acquired and analyzed to show the effects of low frequency vibration on subcooled boiling two-phase flow. Experimental results reveal that area-averaged void fraction will be affected by the variation of vibration frequency and displacement