Hydrodynamic Characteristics of Two-Phase Flow Through Packed Bed with Spheres
The development of Light Water Nuclear Reactors with Micro-Fuel Elements (МFE) is a promising trend in nuclear-power engineering combining the traditional technology of Light Water Reactors (LWR) with the High-Temperature Reactor (HTR) fuel technology. There are considerable advantages of the MFE such as: the larger heat exchange surface, smaller thermal flux and temperature and void reactivity coefficients, etc. Thus Prior knowledge of Hydrodynamic characteristics is essential for the prediction of the flow in new nuclear reactor designs and safety analysis. The flow characteristics of two-phase flow in packed tube are much different than those in hollow tube. Two phase air-water flow regime and void fraction have been experimentally studied. Three vertical transparent tubes, 1m long, with an inside diameter of 0.05m which randomly packed with glass spheres of 2mm, 5mm and 8mm diameters respectively were used as three different types test section. The test runs were done at gas and liquid mass velocities ranging from 0.007 to 1.839 kg/m2s and from 5.093 to 45.837 kg/m2s, respectively. The measured void fractions ranged from 0.16 to 0.79. The flow pattern map was developed from the observed flow patterns I.e. Bubbly flow, slug flow, pulse flow and spray flow. The pulse flow was dominating in the wide rang of gas and liquid velocity. The influence of sphere size, gas and liquid mass flow rates on void fraction were also investigated. It is found that the drift flux data show a dependence on superficial gas velocities. Considering the effect of geometrical characteristic of packed bed on the void fraction, a new and simple correlation of predicting void fraction was proposed and compared with some existing correlations. The proposed provided the best prediction of the experimental void fractions.
Two-Phase Flow Packed Bed Flow Pattern Void Fraction
Nan Zhang Zhongning Sun
College of Nuclear Science and Technology Harbin Engineering University,
国际会议
上海
英文
793-801
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）