球床反应堆燃料元件成组串列管路气力提升方法研究

摘要

为了满足球床高温气冷堆利用气力输送方法实现球形燃料元件多次通过堆芯的循环运行方式的运行经济性和控制可靠性要求,提出了一种成组串列气力提升燃料元件的方法,并从动力学特性、提升效率及压降等方面研究了其具体实现方法.该方法可使燃料元件短暂时间间隔地顺次进入提升管路,并由气力提升至堆芯,在同一时刻,燃料元件组成队列共同占用提升管路.研究结果表明,在燃料元件成组串列气力提升过程中,组内各元件运行平稳,间距可控,可以避免因碰撞导致元件破损.与燃料元件逐一完成气力提升方法相比,采用成组串列气力提升方式有利于在必要时实现反应堆燃料快速循环,而且在维持正常循环时,可以降低提升气体流速和每个燃料元件的运行速度,进而减小元件对堆芯的冲击,并且可以减小系统压降,使球床反应堆更加经济可靠地运行.%To meet the requirements of operational economy and control reliability of a pebble-bed high-temperature gascooled reactor characterized by its fuel elements' repeated pneumatic moving through the reactor core,a scheme for grouped tandem pneumatic lifting (GTPL) of fuel elements in pipelines was proposed,and its corresponding implementation was researched in the aspects of dynamic characteristics,lifting efficiency and pressure drop.By this method,fuel elements are sequentially added to the lifting pipelines with short time interval,and then pneumatically lifted to the reactor core,so the lifting pipelines are occupied by a quene of fuel elements at the same time.The results of the simulation and the experiment show that the new method can make fuel elements move steadily with the controllable spacing between each two fuel elements in GTPL,so the breakage of the elements caused by elementselement collision can be avoided.Compared with the method of lifting the elements one by one,the GTPL scheme has obvious advantages.On one hand it can achieve the rapid fuel cycle if necessary,on the other hand,it can help to reduce the gas flow rate and the moving velocity of each fuel element in normal fuel cycle,and then descend the impact on the core as well as the pressure drop of the operation system.