Flow Structure of Subcooled Boiling Water Flow in a Subchannel of 3 x 3 Rod Bundles

摘要

In this paper, the interfacial flow structure of subcooled water boiling flow in a subchannel of 3 x 3 rodbundles is presented. The 9 rods are positioned in a quadrangular assembly with a rod diameter of 8.2mmand a pitch distance of 16.6 mm. Local void fraction, interfacial area concentration, interfacial velocity,Sauter mean diameter, and liquid velocity have been measured using a conductivity probe and a Pitot tubein 20 locations inside one of the subchannels. A total of 53 flow conditions have been considered in theexperimental dataset at atmospheric pressure conditions with a mass flow rate, heat flux, inlet temperature,and subcooled temperature ranges of 250–522 kg/m2 s, 25–185 kW/m2, 96.6–104.9ºC, and 2–11 K, respectively.The dataset has been used to analyze the effect of the heat flux and mass flow rate on the localflow parameters. In addition, the area-averaged data integrated over the whole subchannel have been usedto validate some of the distribution parameter and drift velocity constitutive equations and interfacial areaconcentration correlations most used in the literature