控制棒水压驱动系统冷态性能实验研究

Experimental Study on Cold State Performance of Control Rod Hydraulic Drive System

控制棒水压驱动系统是清华大学为低温核供热堆NHR200发明的新型的内置式控制棒驱动技术,该驱动系统由水压驱动机构、组合阀、控制棒和缓冲器等组成。控制棒水压驱动系统冷态性能是控制棒步进时间和系统驱动压力选取的基础。本文分析了控制棒水压驱动系统的组成和工作原理,完成了全尺寸控制棒水压驱动系统冷态性能实验,包括水压缸最小落棒压力实验、提升缸带载步进实验和快速落棒实验等。在实验结果的基础上分析了关键特性参数的变化规律和机理。结果表明:最小落棒压力是保持驱动机构销爪正常工作所需的最小驱动压力,其对应于压力时程曲线上峰值波动过程的变化起点;步升和步降过程压力拐点分别对应位移到位点,随着驱动水压的增加,水压缸充压拐点压力逐渐增加,步升时间、充压拐点时间逐渐减少。实验研究成果为控制棒水压驱动系统的设计、优化和工程应用奠定基础。

Control rod hydraulic drive system(CRHDS),which is invented by Institute of Nuclear and New Energy Technology,Tsinghua University for the nuclear heating reactor NHR200,is a new type of internal control rod drive technology.CRHDS is composed of control rod hydraulic drive mechanism(CRHDM),integrated valve,control rod and hydraulic buffer,etc.The cold state performance of CRHDS is the basis to determine control rod stepping time and system driving pressure.The composition and working principle of CRHDS were analyzed in the paper.The full scale CRHDS performance experiments,which include the minimum rod drop pressure test of hydraulic cylinder,step motion test of lifting cylinder and the scram performance test,were carried out under room temperature.Based on the experimental results,the changing laws of the key characteristic parameters of CRHDS were analyzed.The research results show that,the minimum rod drop pressure is the minimum driving pressure for CRHDM to work normally,and it corresponds to the starting point of the peak wave process on the time history curve of cylinder pressure.The inflection points of the pressure curves in the step-up and step-down processes of the control rod correspond to the end points of the step motion respectively.With the increase of the driving pressure,the inflection pressure of the hydraulic cylinder increases gradually,the step-up time and the time of the turning point decrease during the step-up process.The experimental results lay the basis for the design,optimization and engineering application of the CRHDS.