抄録
In the reflux condensation, steam generated in the reactor core and water condensed in the pressurizer form a countercurrent flow in a surge line. The flow is highly complicated because the surge line consists of a vertical pipe, a vertical elbow and an inclined pipe including plural elbows. Detailed measurements of countercurrent flow limitation (CCFL), however, have not been reported. Therefore, in this study, CCFL characteristics in a scale-down model of the pressurizer surge line were measured using air and water as working fluids. As a result, the following conclusions were obtained. (1) Supplied water was limited at either the upper junction, the inclined pipe or the lower junction in the surge line, depending on the inclination angle and air flow rates. (2) The smaller the inclination angle of the surge line is, the stronger the limitation of falling water flow rates in the inclined pipe is.
