水力驱动控制棒极限落棒冷态原理实验

Experiments on Scram for Hydraulic Control Rod Driving System in Utmost Accident at Normal Temperature

针对控制棒水力驱动系统在摩擦力卡棒和倒置等极限工况下的停堆问题,根据控制棒水力驱动系统的工作原理,提出了步进缸内腔卸压的解决方法,并在200MW低温核供热堆控制棒水力驱动系统的1∶1实验台架上进行了冷态实验。结果表明:控制棒的落棒速度明显提高,棒外与棒内差压在卸压一定时间后能够达到较高的数值。说明水力驱动控制棒在冷态摩擦力卡棒和倒置等极限条件下,能够克服一定量的摩擦阻力或能够克服重力插入堆芯。

Based on the principle of hydraulic control rod driving system (HCRDS), the paper gives a new scram method, which makes the inside pressure of step cylinder discharge, to solve the scram problem of HCRDS in control rod hang up accident and inversion conditions, and some experiments were carried out with the 1:1 experimental loop of the HCRDS for the 200 MW nuclear heating reactor (NHR-200). The results show that the control rod falls much quickly than that in normal condition. The differential pressure between the outside and inside of step cylinder can reach a large value after the inside pressure of step cylinder discharge. In other word, the hydraulic control rod, which can overcome certain frictional resistance in control rod hang up accident of its gravity in inversion condition, can insert the nuclear reactor core.