ADU沉淀干燥过程DCS控制设计

The research about DCS controlled drying sediment process in recycle line

核电站燃料元件制造过程中产生的废弃UO2的循环再利用一直是核电制造领域面临的重要课题,由于核废物料含有的杂质不确定性,导致工艺控制参数的调整十分困难。它涉及:煅烧、溶解、萃取、沉淀干燥、还原、等工艺过程,2016年DCS控制系统进行了全面更新,采用浙大中控的ECS700集散控制系统,用光纤连接的分布式网络系统贯穿整个工艺过程。其中ADU沉淀干燥工序是UO2的循环再利用生产的一个重要环节,其产品是ADU粉末。ADU沉淀干燥工艺包括:硝酸铀酰与氨水的连续2级沉淀、1级均匀混合、固液分离、螺旋加热干燥、破碎处理、分装、称重等工序。为贯彻核安全生产法规提出的:核物料的体积重量必须小于物料临界体积重量的要求。在DCS设计中对关键工艺参数采用比例调节阀闭环PID控制调节方式,严格控制物料重量。针对新研制设备在控制方面的缺失,尝试不同的DCS设计方案,不断修改和完善,使设计解决方案达到最优。

the recycling use of waste uo2 in nuclear power station assembly manufacture is the key topic that have to face for. it is hard to predict the foreign substance in waste uo2, so the adjustment of process parameter is very difficulty, uo2 recycling line include：burning process, dissolution process,extraction process, drying sediment precess, reduction process, all this process to be called recycle line. in 2016 the recycle line control system is totallly reformed by ECS 700 system, the fibre optic network link eve- rywhere through out the recycle line. one of the most important process is. drying sediment process, it is an interal process in recycle inc. include ： two stages ADU sediment and one stage equality mixture, liquid solid separation, screw drying, Smashing, weighting, according to the nuclear security manufacture laws：volume and weight must less than the critical value, key parameter in uo2 recycling line is controlled by PID pattern, so material＇s weight is under strictly controlled, in case of defect in new design machine, continue improvement and optimize is needed, as a result reliable and stable control in recycling line to have come true.