漂移模型参数对两相流分析的影响

Effect of parameter in drift model on two phase flow analysis

分析了５ＭＷ核供热堆热工水力学模拟实验回路ＨＲＴＬ－５中的两相流及两相流稳定性特性。指出在采用带有质量，蒸汽质量，能量及动量守恒方程的一维两相流漂移模型分析时，空泡份额分布参数Ｃｏ及漂移速度Ｖｖｊ的选择对系统稳态及动态分析结果都会产生很大的影响。其中Ｃｏ对稳态流量的计算结果影响不大，通常可以忽略。在Ｖｖｊ为０．０～０．６ｍ／ｓ的范围内，Ｖｖｊ对稳态流量的计算结果有６％的影响，但对加热段出口空泡份额的影响却有５３％。均匀流模型（Ｃｏ＝０．０，Ｖｖｊ＝０．０）与漂移流模型（Ｃｏ＝１．１，Ｖｖｊ＝０．４８）对两相流稳定边界的预测相差１５％。本研究选用Ｃｏ＝１．１，Ｖｖｊ＝０．４８。漂移模型对系统稳态及动态的分析结果都与实验值相吻合。

This paper investigates the behavior of two phase flow and flow instability in a 5 MW nuclear heating reactor test loop HRTL 5, which simulates the grometry and system design of the 5 MW reactor. It points out that the chose of distribution parameter C o and drift velocity V vj may have significant effect on the result of static and dynamic analysis of the system, when one dimensional two phase flow drift model with conservation equations for mass, steam, energy and momentum was used. C o has no great effect on the steady mass flow rate, usually it can be ignored. In the range of V vj =0.0￣0.6 m/s, V vj has about 6% effect on the steady mass flow rate, but has 53% effect on the void fraction at the exit of the heated section. The result by drift model ( C o=1.1, V vj =0.48) shows 15% difference from that by homogeneous model ( C 0=1.0, V vj =0.0) on the predicting of instability boundary. In this analysis C o=1.1 and V vj =0.48 are used. Calculated results of both static and dynamic states by drift model agree with experimental data well under the 5 MW nuclear reactor conditions.