带管道铀床回收氘气过程分析  

Deuterium Absorbing Process Through Uranium Bed With a Small Pipe

作　　者：王伟伟[1] 龙兴贵[1] 陈绍华[1] 余铭铭[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《原子能科学技术》2010年第8期930-933,共4页Atomic Energy Science and Technology

摘　　要：在ICF实验用微球靶充气工艺系统中,通过测试管道中氘气压强p与时间t的变化关系,研究了室温下铀床回收氘气的动力学过程。用数据处理软件Origin拟合p-t曲线,得到了氘气吸收速率方程,讨论了速率方程中各参数的物理意义以及影响因素。9×10-4m3氘气罐中初始压强p0=0.6MPa的氘气通过长2.3m、孔径1～2mm不锈钢管道,与铀床反应30s后压强降为0。通过计算流体平均雷诺数Re发现,随着压强不断下降,氘气在管道中流动状态逐渐从湍流向层流转变。压强随时间的变化规律符合一次指数衰减曲线,t=0～12s时湍流状态下的速率方程满足p(t)=y0+A1exp(-t/t1)(y0=0.05～0.1MPa,为非湍流状态下铀床的吸氘量;A1=0.5～0.6MPa,为反应初始氘气量;t1=3.3～3.7s)。该过程可看作一级反应,决速步骤为氘气在管道中的扩散,反应速率常数k=1/t1,半衰期τ=t1ln2。在室温(20℃)下,减少铀床中初始氘含量可提高反应速率常数k。层流状态下的回收过程需进行进一步探讨。In the ICF micro-sphere target filling system,in order to study the recovery of hydrogen isotopes at room temperature by a uranium bed through a small pipe,deuterium pressure（p）in a stainless iron vessel vs time（t）was recorded.The p-t curve was fitted by software Origin,and the fitting curve was discussed.Deuterium gas in a 9×10-4 m3 vessel,flows through 2.3 m stainless iron pipe with inner diameter D=1-2 mm,and the pressure drops from p0=0.6 MPa to zero within 30 s.The gas flow state transits from turbulent flow to laminar flow,according to the calculated average Reynolds number（Re）.t=0-12 s,the relation between p and t satisfies first-order exponential decay curve,i.e.,p（t）=y0＋A1exp（-t/t1）,in which y0=0.05-0.1 MPa,A1=0.5-0.6 MPa,t1=3.3-3.7 s.y0 shows the deuterium uptake in the laminar flow state,A1 refers to initial deuterium pressure p0.The recovery process can be regarded as a first-order reaction,and the rate-determining step is deuterium diffusion through the gas pipe,reaction constant k=1/t1,the half-lige of the recovery process in turbulent flow state τ=t1ln 2.The reaction constant k rises with reduction of initial deuterium content in U-bed.The condition in the laminar flow state needs further investigation.

关 键 词：铀床 吸氘反应 一级反应 湍流 

分 类 号：O641.62[理学—物理化学]