微流体惯性撞击器气溶胶过滤行为研究

微流体惯性撞击器可作为安全壳过滤排放系统的第一级过滤装置,实现严重事故后安全壳快速泄压并对壳内放射性气溶胶进行初效过滤。为了探究惯性撞击器内气溶胶的过滤行为,开展可视化实验对气溶胶在惯性撞击器内的沉积分布进行研究。研究表明,可视化实验能反映撞击器内气流流向及气溶胶运动轨迹。气溶胶在过滤单元处的沉积位置主要集中在过滤单元的上表面及微流道的内壁面,过滤效率可达60%以上。同时,由于撞击器通道表面特性随气溶胶的沉积而改变,容尘条件下的气溶胶过滤效率逐渐增加。而当惯性撞击器内载气流速大于临界值时,过滤效率会因气溶胶的再悬浮而降低。     

不锈钢过滤材料的过滤特性

利用混合标准粒子和邻苯二甲酸二辛酯（DOP）多分散气溶胶,采用扫描迁移粒径仪分析气溶胶全粒径谱,作为测定各级粒径过滤效率的方法,对几种不锈钢过滤材料进行过滤特性研究。研究结果表明,对于多分散气溶胶,不同孔径和性质的金属滤材的最大透过粒径D_max是不同的,D_max随滤材过滤孔径的增大而变大;在1～3cm/s滤速区间内,滤材的效率随滤速的增加而降低,且滤材的D_max随滤速的增加向小粒径方向移动。不锈钢滤材串级过滤时表现出各级滤材的效率依次降低,但串级过滤的总过滤效率仍随级数的增加而增大;实验还证明,滤速一定时,相同滤材串级过滤并不会改变过滤器的D_max,但观察到串级过滤各级单级效率的D_max有随级数的增加向大粒径方向移动的现象。     

PP-K_2型丙纶过滤材料性能的研究

为了研究放射性作业条件下高效的呼吸道个人防护用具,对过滤材料除应具有过滤效率高、呼吸阻力小、抗拉强度好以及价格便宜外,根据现场的复杂条件,还应具有耐温、湿、酸、碱、有机溶剂以及耐辐照等理化特性。为此,我们于1979年在上海纺织科学院的大力协助下,开展了对丙纶过滤材料的小样研制工作,在1980年和上海第一制毡厂进行了丙纶过滤材料的大样研制工作。经一年多的努力,初步研制出一种“PP-K_2”型丙纶过滤材料。     

核反应堆用除雾器过滤效率的数学模型

通过数值模拟方法计算了除雾器对于5～10μm水滴的过滤效率。针对玻璃纤维的结构特点以及除雾器过滤水滴的实际情况,将混合丝网的网孔分为标准型、毛刺型和中间型;对于金属丝和标准型网孔的竖直丝,使用描述绕圆柱体气流流动的桑原(Kuwabara)流场模型,其余情况的网丝,使用描述绕平板气流流动的平板流场模型。通过计算粒子在流场中的运动轨迹,获得整体除雾器对水滴的过滤效率。将数值模拟结果与实验测量结果进行了分析对比,两者的吻合程度在合理的范围之内。     

同步辐射X射线荧光微探针对单个流体包裹体的探测分析

本简述流体包裹体研究的意义。介绍在BSRF的实验条件下，用同步辐射X射线荧光微探针对单个流体包裹体作无损成分分析实验探索，包括样品的制备、流体包裹体鉴别和选择及在工作平台上对它们作显微对光，进行探测等。在20×10μm^2和10×10μm^2束斑下对几种类型流体包裹体作了测试分析，并对结果作了讨论。     

塑料微球强度和渗氘性能测量

摘要：针对激光惯性约束聚变物理实验打靶所需的氘氚燃料塑料微球靶进行微球强度和渗氘性能初步研究,测量了塑料微球球壳在20（室温）、40、60℃下的压缩强度,并实验测得了塑料微球在20、60℃下的氘气渗透率。     

用大涡模拟计算流致振动的流体激励力

本文对湍流大涡模拟理论的脉动过滤和Smagorinsky亚格子模型进行了介绍,并用大涡模拟对秦山II期反应堆1∶5模型压力容器和吊篮的环腔内流场进行了数值模拟,计算了吊篮表面压力的时间分布和空间分布,其压力脉动的功率谱密度计算值和实验值在同一个量级内.因此,可以用计算所得的压力作为吊篮振动的激励载荷.     

柴达木盆地油砂层中两组典型单个流体包裹体的SRXRF微束分析

油砂是储层中显示油气的主要矿物之一。本描述了柴达木盆地油砂中油气层组N12/N^2 1单个流体包裹体特征．给出了它们的SRXCRF微束无损分析的结果。对同一层位的共同性及不同层位间的变化特点作出了讨论．     

激光惯性约束聚变裂变混合能源包层中子学数值模拟

对三维输运与燃耗耦合程序MCORGS进行了适应性改造,并对利弗莫尔实验室提出的激光惯性约束聚变裂变混合能源(LIFE)概念进行了分析和改进。输运计算采用MCNP程序,燃耗计算采用ORIGENS程序,增加氚控制模块和功率控制模块。建立了与LIFE等价的以贫化铀为燃料、Be为中子增殖剂的包层方案,通过数值模拟验证了MCORGS程序的可靠性。针对Be资源短缺及冷却复杂问题,设计了以贫化铀为燃料、Pb为中子增殖剂的包层方案,包层能量放大了4倍,可在55a内稳定输出2 000 MWt功率。     

Calibration of Cascade Impactor by Two-Stage Method

A simple method of calibrating the cascade impactor has been developed by applying Hongo et al.'s two-stage method to evaluate the particle-size distribution. The constants ψ and σfor a function representing the impaction efficiency were determined for the UNICO cascade impactor, using the test particles produced by a spinning-disc aerosol generator. The values were ψ=0.35, σ=1.46, respectively.

The validity of the method for the UNICO cascade impactor was confirmed from microphotographic observation of a sample artificial aerosol containing different sizes of uranine methylene-blue particles. Both the mass median aerodynamic diameter and the geometric standard deviation obtained with the method agreed with the microphotographie measurements with relative errors not exceeding 10%.     

Modeling analyses of radioactive aerosol flow and collection in mesoscopic impactor filters

The concentration of radioactive aerosols in the containment increases rapidly during the serious nuclear accidents. The common aerosol filters use mesh structures or filter papers, which can significantly increase the flow resistance due to the aerosol deposition and retard the containment pressure relief following the nuclear accidents. This paper proposes and studies a MEMS (Micro Electro Mechanical Systems) inertial impactor filters which can filtrate and collect 1 to 3 microns aerosol particles without filter papers. It can significantly reduce the flow resistance in filtering micron-size aerosol particles. The modeling method is given and the simulation results are analyzed.     

Structure of Flow Fields in Low Pressure Impactor

In order to clarify the detailed flow fields of impinging jets in a low pressure impactor, nitrogen and argon flow fields are investigated experimentally and numerically at a relatively small range of P _down/P _up, where P _down is the downstream stagnation pressure and P _up the upstream stagnation pressure. The pressure at the center of collection plate, P _c, is measured in addition to the flow visualization by Laser Induced Fluorescence (LIF) technique, which is used in previous study. Furthermore, the flow fields in a low pressure impactor have been simulated by solving the axisymmetric Euler equation through Harten-Yee TVD method. The effects of P _down/P _up and H/D on flow fields are examined in detail, where H is the jet-to-plate distance and D the nozzle diameter. The calculated shock wave position on jet axis and the pressure at the center of collection plate are in reasonable agreement with the experimental results. It is found that the structure of flow fields changes drastically at a certain value of P _down/P _up and there exist hysteresis phenomena in the relationship between the value of P _c/P _up and that of P _dowb/P _up for both gases. The formation of the separation bubble at a certain value of H/D is discussed.     

Flow in Low Pressure Impactor and Collection Efficiency of Particles

An effect of specimen size on the Charpy impact property was evaluated in the ferritic-martensitic 11Cr-0.5Mo-2W, Nb, V stainless steel (PNC-FMS). The upper shelf energy (USE) is expressed by the power law equation as USE[J]=m(Bb) ⁿ where m is the material constant (m=0.277 in PNC-FMS), B[mm] is the specimen thickness and b[mm] is the ligament size. The normalizing exponent n was empirically derived using the USE of the full size specimen as n=1.38×10^–3USE_full+1.20. The n value varies in the range of 1.2 to 1.7, which is affected by the fracture volume below the notch. The PNC-FMS wrapper takes n=1.42. The ductile-to-brittle transition temperature (DBTT) of PNC-FMS is correlated as DBTT=115(log₁₀ BKt)—158 using an elastic stress concentration factor Kt that represents the effects of notch size, e.g. notch depth, notch root radius and notch angle.     

惯性约束聚变低温冷冻氘氚靶制备技术

低温冷冻氘氚靶对于惯性约束聚变研究至关重要,主要有塑料微球靶、金属铍球靶、泡沫球壳靶等。根据微球球壳材质的不同,采用不同的低温冷冻氘氚靶制备技术。塑料微球靶采用“高压充氘氚-冷冻法”或“充气管充气法”;金属铍球靶采用“低温、低压冷凝法”或“高温、高压扩散连接半球壳法”;多孔泡沫球壳靶采用“球壳材料吸附氘氚液体法”。本文简述上述技术和方法的发展状况和趋势。     

主循环泵惯性飞轮完整性分析

核反应堆主循环泵上安装储能飞轮，能够为反应堆在断电事故下提供冷却剂，避免堆芯损坏。储能系统的结构完整性直接关系到反应堆的安全。本文采用非线性接触算法，利用有限元软件对主循环泵飞轮进行完整性分析。考虑过盈、额定转速和超速等载荷工况，从结构强度和断裂力学两方面进行了分析。计算结果表明，飞轮的结构强度及假想缺陷处应力强度因子均满足标准要求，在规定工况下能够保证其结构完整性。     

可加工SiO2气凝胶及其惯性约束聚变靶微柱制备

以正硅酸乙酯（TEOS）为前驱体，采用酸碱两步催化法制备SiO₂醇凝胶。醇凝胶分别经TEOS母液、六甲基二硅胺烷（HMDSA）处理后，采用CO₂超临界干燥法制备出密度在30～100mg/cm³的SiO₂气凝胶。用傅立叶变换红外光谱（FTIR）对疏水性SiO₂气凝胶进行了表征，并用扫描电镜图研究了气凝胶改性前后的微观网络结构。改性后的气凝胶微观骨架变大，部分细小的网络结构消失。改性后的气凝胶在潮湿环境中具有极好的尺寸稳定性和疏水性能。用精密车床加工出了满足惯性约束聚变物理试验要求的ICF靶微柱。