高放废液冷坩埚玻璃固化自适应负压调节系统的设计

Design of Adaptive Negative Pressure Regulating System for Glass Solidification of HLLW by Cold Crucible

在两步法冷坩埚玻璃固化冷台架运行过程中,冷坩埚和煅烧炉的压力控制十分重要。由于高放废液中盐分的周期性分解以及设备密封问题等,会导致设备内压力波动较大,如果压力控制不足,极易引发放射性泄漏或尾气系统堵塞和排放超标。本文针对现阶段高放废液冷坩埚玻璃固化冷台架关键设备负压控制存在的大惯性、非线性、大滞后以及不确定性等问题,利用模糊算法设计了一套自适应负压调节系统。本系统建立的模糊算法可根据采集到的数据来预测可能的压力波动,并结合PID控制主动通过调节电磁补气阀控制负压。通过Simulink仿真模块建立了自适应负压控制器仿真模型,并采用历史运行数据对本自适应负压调节系统计算得到的补气量能否维持煅烧炉内的负压稳定进行了实验验证,结果显示,负压偏差积累量降低了98.64%,表明采用自适应负压控制器能有效降低压力波动,并消除泄漏隐患。

During the operation of two-step cold crucible glass solidification device, the pressure control of cold crucible and calciner is very important. However, due to the periodic decomposition or sealing problem of calcined products, there will be large pressure fluctuation. If the pressure control is insufficient, it is easy to cause leakage or bring excessive radioactive substances into the tail gas system, resulting in excessive emissions. Therefore, aiming at the problems of large fluctuation, nonlinearity, large delay and uncertainty in the negative pressure control of glass solidification cold bench of HLLW based on cold crucible, an adaptive negative pressure control system was designed by using fuzzy algorithm. The fuzzy algorithm established in this system can predict the possible pressure fluctuation according to the collected data. Combined with PID control, the negative pressure can be controlled by adjusting the electromagnetic air supplement valve. The simulation model of the adaptive negative pressure controller was established through the Simulink module of MATLAB, and the historical operation data were used to verify whether the air replenishment calculated by the adaptive negative pressure regulation system can maintain the negative pressure stability in the calciner. The results show that the accumulation of negative pressure deviation is reduced by 98.64%, and it is proved that the adaptive negative pressure controller can effectively reduce the pressure fluctuation and eliminate the hidden danger of leakage.