无保护失流条件下SFR液体悬浮式PSS移动体的运动及动力特性研究

分析了钠冷快堆（SFR）液体悬浮式非能动停堆组件（PSS）移动体在下落过程中所受水力阻力及其计算方法。根据PSS内部流体网络，对移动体悬浮及下落过程中的流量分配和水力阻力分布进行了分析和建模，使用准稳态结合瞬态修正的方法对移动体运动过程进行了计算。分析了移动体在无保护失流条件下下落运动的时程。结果表明：移动体在下落过程中的速度和加速度逐渐增大、所受水力阻力减小；移动体下落0.588 m的时间为6.68 s。移动体下落时间的计算结果满足初步设计要求，可作为分析计算PSS落棒时间的参考。

Performance Study of Moving Body Dynamics in Hydraulic Suspended PSS for SFR under Unprotected Loss of Flow Accident

The hydraulic resistance of the moving body within hydraulic suspended passive shutdown subassembly (PSS) for sodium cooled fast reactor (SFR) in the process of falling and its calculation method were analyzed. Based on the internal flow path of PSS, the flow rate distribution and hydraulic resistance distribution during PSS moving body suspension and falling process were analyzed and modeled. The motion process of the moving body was calculated by using quasi-steady state combined with transient correction method. Based on the above calculation method, the time course analysis of the falling motion of the moving body during the unprotected loss of flow accident was completed. The result shows that during the falling of the moving body, the velocity and accelerated velocity rise, and the hydraulic resistance drops. The moving body which drops for 0.588 m needs 6.68 s. The calculation result of moving body falling time meets the preliminary design requirement and can be used as a reference for PSS design.