VOID FRACTIONS IN VERTICAL-TO-HORIZONTAL COUNTER-CURRENT TWO-PHASE FLOWS

摘要

Results on the slugging phenomena in CCF carried out with a test section having vertical-to-horizontal legs, with different types of orifices installed at two locations in the horizontal leg have been presented. In general it is observed that the flow conditions required to produce the first slug correspond to the onset of flooding. These conditions are affected by the size of the orifice but it seems that they are not affected by the position of the orifice with respect to the elbow. For low gas velocities the average void fractions are affected by the gas velocity, however, for high gas velocity and for the cases having and orifice, an asymptotic void fraction value is observed. For the cases without orifice this value seems to be much higher. Moreover the present results show that the average void fractions do not depend on the orifice size nor on their position with respect to the elbow.