ICONE23-1406 EXPERIMENTAL MEASUREMENT OF TWO-PHASE FLOW PARAMETERS IN LARGE CHANNEL

抄録

Two-phase flow parameters were obtained for air-water flow in a rectangular channel which is 15 cm in hydraulic diameter. The test section includes horizontal, inclined and vertical channel sections in a loop test facility. A double conductivity probe method was employed to measure the flow parameters. Air was injected from the top side of the channel which induced the natural circulation of water inside the test section. The natural circulation flow rate of liquid was measured by a paddle type flow meter installed at the downcomer side in which only a single phase liquid flow existed. The probes mounted on the top of the test section were set at various locations along the channels. From the raw probe data, the experimental results are presented on the statistical averaged data of local void fraction, gas velocity and bubble chord length distribution. In addition, the turbulence intensity was deduced from fluctuation of gas velocity. The flow regime observed through high speed camera indicated the existence of elongated bubble flow in the inclined section and bubbly or transition from bubbly to churn turbulent flow in the vertical section. The data on flow parameters associated with its behavior in the channels facilitates the understanding of twophase flow in large diameter pipes which has an extensive application in nuclear engineering.