管道贯穿裂纹泄漏率预测

充分考虑入口为过冷水、两相和过热蒸汽等情况下的临界和非临界流动,对摩擦压降、拐角压降以及临界流模型Henry-Fauske中的相变起始点进行了修正,开发出破前泄漏(LBB)的管道贯穿裂纹泄漏率计算程序。与目前通用的裂纹泄漏率程序(PICEP和SQUIRT)分别就常规直管道、人工裂纹以及自然形成裂纹的泄漏率实验数据进行了对比。计算分析表明,该程序计算结果与实验结果吻合较好且精度高于PICEP和SQUIRT。此外,通过计算分析研究,获得了背压和滞止焓以及裂纹形貌(包括局部粗糙度、全局粗糙度及裂纹开口位移、裂纹拐角数目等)对泄漏率的影响规律。

Prediction of Leakage from Through Pipeline Crack

A code was developed to predict the leakage from through pipeline crack of the leak before break (LBB), and various stagnation conditions were considered, including the subcooled water, the two-phase fluid and the superheated steam. Both the critical and non-critical flows were studied. The Henry-Fauske critical flow model was revised by a new phase transition point and the pressure drops of friction and turns were modified. The code was verified by comparing with the experimental data of conventional straight pipe, artificial crack and naturally occurring crack, which shows a good agreement and the code has a higher precision than the existing codes PICEP and SQUIRT. The influence of crack morphology on LBB leakage was discussed, including the local roughness, the global roughness, the crack open displacement and the number of the corners. Besides, the dependence of the LBB leakage on stagnation enthalpy and back pressure was investigated.