自然循环两相漂移流理论分析模型的建立

以5MW核供热堆试验回路（HRTL－5）为物理原型，从理论上推导了加热段欠热沸腾，上升段入口附近的冷凝，上升段闪蒸以及气空间压力平衡等关系式，并考虑了热力不平衡等因素的影响，建立了一个完整的四方程漂移流模型，该模型适用于分析低压低干度自然循环系统的流动问题，通过引入凝边界层，首次解决了两相流动过程中汽泡在过冷水中的冷凝问题，对汽空间则推导了压力及液位的约束方程，方程组可采用积分方法求解，并利用Rung-Kutta-Verner方法求解所得的微分方程组。

Theoretical Model of Two-Phase Drift Flow on Natural Circulation

Some expressions, such as sub-cooled boiling in the heating section, condensation near the riser inlet, flashing in the riser, and pressure balance in the steam-space, have been theoretically deduced from the physical model of 5MW heating reactor test loop. The thermodynamics un-equilibrium etc have been considered too. A entire drift model with four equations has been formed, which can be applied to natural circulation system with low pressure and low steam quality. By means of introducing the concept of condensation layer, condensing of bubbles in the sub-cooled liquid has been formulated for the first time. The restrictive equations of the steam space pressure and liquid level have been offered. The equations can be solved by means of integral method, then by using Rung-Kutta-Verner method the final results is obtained.