V形板除尘设备的数值模拟和试验研究

研究了基于涡流理论的V形板除尘设备,利用数值模拟的方法确定了除尘器的基本尺寸之后,将除尘效率和压力损失作为本试验的主要考核指标,进行正交试验和后期数据处理。根据试验效果得出:对平均粒径为5μm的滑石粉,当V形角度为60°,前后两排V形板距离50mm,进口速度为3m/s时,除尘器整体性能最优,总除尘效率为61%,压力损失为40Pa。     

三级克劳斯工艺的应用及改造

介绍了普通三级克劳斯硫黄回收工艺流程及装置运行情况,阐述了试生产前期改造、试生产后的改造以及第1次大修时的改造情况。通过2年多的运行,该硫回收装置可满足连续生产的要求,排出的尾气中φ(H2S+SO2)基本能够达到≤0.6%的设计要求。     

除尘器滤料性能认证介绍

本文介绍了美国环保局（EPA）环境技术认证项目（ETV）中对袋式除尘器滤科性能的检测方法和结果，给国内外广大除尘设备用户在选择滤料时提供了数据上的参考。     

新型平板太阳能PV/T空气集热器传热特性的数值研究

文中设计了一款新型PV/T一体化空气集热器,建立了新型PV/T空气系统内部传热过程的一维非稳态数学模型,并利用差分法对模型进行了数值计算。根据计算结果对一体化系统的性能及影响因素进行了分析。结果表明:在一定的光照强度下,随着空气质量流量增加,电池板温度Tp逐渐下降,空气温升逐渐降低;而热效率、光电转化效率、联合效率随空气流量的增加有所升高。模型的建立为高性能太阳能PV/T一体化空气集热器的优化设计提供较好理论依据。     

隔声复合材料隔声性能的数值模拟及实验研究

根据隔声原理,制备了一种内部均布钢球的玻璃纤维增强树脂基隔声复合材料。分别使用数值模拟与实验研究的方法研究了复合材料的隔声效果。模拟数值结果和实验结果均显示了隔声复合材料有良好的隔声性能。针对阻抗管测量隔声方法,利用有限元方法得到了材料隔声量的数值模拟结果。均值材料计算结果与理论结果的比较以及隔声复合材料的计算结果与实验结果的比较,证明了该数值模拟方法在模拟材料隔声量的有效性与可行性。     

Design and Performance of a Low-Cost Micro-Channel Aerosol Collector

Aerosol sampling and identification is vital for assessment and control of particulate matter pollution, airborne pathogens, allergens and toxins, and their effect on air quality, human health, and climate change. Assays capable of accurate identification and quantification of chemical and biological airborne components of aerosol provide very limited sampling time resolution and relatively dilute samples. A low-cost micro-channel collector (μCC) which offers fine temporal and spatial resolution, high collection efficiency, and delivers highly concentrated samples in very small liquid volumes was developed and tested. The design and optimization of this μCC was guided by computational fluid dynamics (CFD) modeling. Collection efficiency tests of the sampler were performed in a well-mixed aerosol chamber using aerosolized fluorescent microspheres in the 0.5–6 μm diameter range. Samples were collected in the μCC and eluted into 100 μL liquid aliquots; bulk fluorescence measurements were used to determine the performance of the collector. Typical collection efficiencies were above 50% for 0.5 μm particles and 90% for particles larger than 1 μm. The experimental results agreed with the CFD modeling for particles larger than 2 μm, but smaller particles were captured more efficiently than predicted by the CFD modeling. Nondimensional analysis of capture efficiencies showed good agreement for a specific geometry but suggested that the effect of channel curvature needs to be further investigated.

Copyright 2014 American Association for Aerosol Research     

Studies on 3D Printability of Novel Impact Modified Nylon 6: Experimental Investigations and Performance Evaluation

The development of functional polymer parts with complex geometrical shape has been possible through additive manufacturing. In this research work, the issues such as warping, filament clogging, and layer delamination related to fused deposition modeling-based 3D printing of nylon 6 are focused and its poor printability is improved. Nylon 6 is toughened by blending with an impact modifier, ethylene terpolymer. Complex viscosity, storage, and loss moduli of modified nylon increase significantly, which help to improve 3D printability of nylon 6. 3D printing of modified nylon is performed at optimized conditions, such as printing temperature, print speed, bed temperature, and cooling speed. Izod impact strength of 3D printed nylon 6-based blend is observed ≈543 J m⁻¹, which is significantly higher than the value (48 J m⁻¹) available in literature for injection molded pristine nylon 6. Thermomechanical analysis of modified nylon shows higher coefficient of linear thermal expansion in normal direction as compared to that in flow direction, which is due to the orientation of polymer crystals during processing. The voids are observed on the cross-sectional surface of impact fractured sample, which are responsible to produce light-weight 3D printed specimens.     

复合杆式射流成型及威力性能的数值模拟及试验验证

为了阐明复合杆式射流的性能,设计了8种不同材料的复合球缺罩,包括聚乙烯/铜、铝/铜、钛/铜、铁/铜、铜/铜、钼/铜、钽/铜、钨/铜材料,并采用LS-DYNA软件对其杆式射流的成型过程进行三维数值模拟,分析了杆式射流威力性能,通过静破甲试验验证了数值模拟结果。结果表明,在保持内罩材料为紫铜的条件下,随着外罩材料密度的增大,射流整体速度减小,射流动能随外罩材料密度的增大而减小;在外罩为金属材料时,外罩材料冲击阻抗越大,内罩所受爆轰波透射压力越小,射流整体速度、射流动能随外罩冲击阻抗增大而减小;经对比发现,聚乙烯/铜复合杆式射流整体速度最高,动能最大,破甲威力较佳,铝/铜复合杆式射流次之。静破甲试验结果表明,聚乙烯/铜复合杆式射流对钢靶侵彻深度较铝/铜复合杆式射流有一定提高,与数值模拟结果一致。     

Comparison of Experimental and Numerical Studies of the Performance Characteristics of a Pumped Counterflow Virtual Impactor

Experiments and Computational Fluid Dynamic (CFD) simulations were performed to evaluate the performance characteristics of a Pumped Counterflow Virtual Impactor (PCVI). The diameter at which 50% of the particles were transmitted was determined for various flow configurations. Experimentally determined 50% cut sizes varied from 2.2 to 4.8 micrometers and CFD predicted diameters agreed within ±0.4 micrometers. Both experimental and CFD results showed similar transmission efficiency (TE) curves. CFD TE was always greater than experimental results, most likely due to impaction losses in fittings not included in the simulations. Ideal transmission, corresponding to 100% TE, was never realized in either case due to impaction losses and small-scale flow features such as eddies. Areas where CFD simulations showed such flow recirculation zones were also found to be the locations where particulate residue was deposited during experiments. CFD parametric tests showed that PCVI performance can be affected by the nozzle geometry and misalignment between the nozzle and collector orifice. We conclude that CFD can be used with confidence for counterflow virtual impactor (CVI) design. Modifications to improve the performance characteristics of the PCVI are suggested.     

阳离子捕收剂醚胺对硫铁矿的试验研究

通过浮选试验,比较了阳离子捕收剂醚胺FX-13,硫醚胺FX-15与丁基黄药和十二胺对硫铁矿捕收性能的影响。试验结果表明硫醚胺FX-15能在低碱度(p H=8~10)以较少用量(2.4 g/t)显著提高硫铁矿的回收率。用FX-15作捕收剂反浮选硫铁矿可获得硫品位为50.79%,回收率为95.54%的优质硫精矿,是实现常温浮选硫铁矿的理想的捕收剂。     

Performance Evaluation of a Two-Stage Entrained-Flow Coal Gasifier Using Numerical Simulation

An advanced air-blown two-stage entrained-flow coal Mitsubishi Heavy Industries (MHI) gasifier is numerically studied under actual conditions. The simulation results are verified first with actually measured data of an industrial MHI gasifier. Then, the effects of different parameters such as the sizes of pulverized coal particles, devolatilization parameters, and operating pressure on the gasifier performance are investigated. The results indicate that as the coal particle size increases, the syngas temperature at the gasifier exit rises while the reactivity of the coal particle decreases. Reducing the operating pressure can have a negative effect on the gasifier throughput while the opposite trend is observed for higher operating pressure.     

FAE 云雾形成过程的实验研究

描述了用高速摄影法研究ＦＡＥ形成过程云雾运动特性的实验，通过对实验记录数据的分析，给出了在爆炸抛撒过程中，燃料空气云团的形状随时间的变化及云雾膨胀速度－时间关系曲线，并对云雾运动特性作了定性分析。     

重油催化装置三级旋风分离器故障分析及改造

结合重油催化装置2005年停工和2006年三旋改造情况,从第一再生器风量、催化剂性质、单管内部流场等方面分析了PSC-250型单管的失效过程。阐述了单管改造原理,并提供改造前后数据对比,为三旋运行监控和故障判断提供了依据。     

新型旋风-布袋组合式除尘器的除尘机理及数值模拟

介绍了旋风-布袋组合式除尘器的结构及除尘机理,建立了数值模型并进行了模拟。认为旋风一布袋组合式除尘器有利于简化除尘结构、节省占地空间、延长滤袋使用寿命、提高除尘效率,利用数值模拟可以指导并优化旋风一布袋组合式除尘器的设计。     

集热式太阳能污泥干化系统能效评估与适应性分析

污泥集热式太阳能干化技术改变了太阳能利用形式,采用恒定的加热温度,相对于温室型太阳能干化技术能够提高干燥效率,保证系统稳定运行。文章通过对该系统的物料和热量衡算得出,在不采用辅助能源时,干化时间、单位面积处理能力、干化床占地面积均与太阳能辐射强度成反比例函数关系,集热器占地面积随着污泥处理量增加而增大,且均大于干化床的占地面积。结合系统投资与运行成本分析,随着干化时间延长处理费用增加,当干化时间为10~15天时,可使污泥日处理费用达到最低。因此,考虑到干化床和集热器的占地面积,该系统适用于处理规模小且所在地区太阳能辐射强度大的污水处理厂。     

海上D油田蒸汽泡沫驱提高采收率实验研究

中国海上稠油资源丰富,其高效开发意义重大.以渤海D油田特稠油为研究对象,通过室内实验,采用一维驱替实验与微观驱替实验研究了蒸汽泡沫驱提高采收率作用机理.结果表明:起泡剂F8具有优异的耐温性能,350℃条件下,仍能发挥较好的泡沫性能,能满足油田蒸汽开发需要;起泡剂不仅能降低油水界面张力还能降低残余油饱和度改变相渗曲线;温度与药剂之间存在互补的作用,随着温度升高,蒸汽的热作用处于主导,泡沫的作用减弱.通过本次实验研究,发现泡沫的主要作用机理是通过起泡剂降低油水界面张力,对岩壁原油进行剥离,同时通过乳化降低原油黏度,提高油相的流动能力,降低水相的流动能力,并通过贾敏效应对含水较高的高渗通道进行封堵,提高低渗层的动用,扩大波及,从而提高最终采收率.     

Experimental and Numerical Study of Serpentine Flow Fields for Improving Direct Methanol Fuel Cell Performance

Methanol crossover is an important issue as it affects direct methanol fuel cell (DMFC) performance. But it may be controlled by selecting a proper flow field design. Experiments were carried out to investigate the effect of single, double and triple serpentine flow field configurations on a DMFC with a 25 cm² membrane electrode assembly (MEA) with a constant open ratio. A three dimensional model was also developed for the anode of the DMFC to predict methanol concentration and cell current density distributions. Experimental and model results show that at lower methanol concentrations (0.25–0.5M), single serpentine flow field (SSFF) provides high peak power density, while a double serpentine flow field (DSFF) gives high peak power density at a high methanol concentration (1–2M). Single and double serpentine flow fields exhibit the same peak power density (33 mW cm⁻²) at 1M. But the cell efficiency of double serpentine flow field is 12.5% which is 3.5% point greater than single serpentine flow field. This is attributed to reduced mixed potential. triple serpentine flow field (TSFF) shows the lowest peak power density and cell efficiency, which is attributed to high mass transfer resistance.     

FAE燃料炸药抛散蹿火失效的实验研究

燃料空气炸药形成支雾时发生蹿火是燃料分散失效的一种重要模式,本文对模型弹的蹿火失效和发生的原因、点火源、点火位置及防止办法进行了实验分析。结果分析,对特定燃料,蹿火的点火源主要是中心分散药的高温产物,点火位置是模型弹结构的两个端部。     

高聚物黏结剂对RDX基含铝炸药性能影响的数值计算及实验验证

为研究乙烯-醋酸乙烯酯共聚物(EVA)对RDX基含铝炸药性能的影响,在A-IX-II炸药中添加EVA制备了含铝PBX炸药。用分子动力学(MD)方法计算了黏结剂EVA与A-IX-II炸药各组分的结合能以及作用方式、AIX-II炸药及含铝PBX炸药的力学性能。计算结果表明,EVA与A-IX-II炸药各组分的结合能均大于0,相互作用力以范德华力为主;EVA能够显著提升A-IX-II炸药的力学性能,使其弹性模量从20.58GPa升至33.27GPa。对A-IX-II炸药和含铝PBX炸药进行了静态力学性能试验,计算结果与试验结果一致性较好。     

Mathematical Model of Heat Transfer in a Solar Collector and Its Experimental Validation

A mathematical model is proposed for heat transfer in a system involving a solar collector and a heat exchanger. An analytical solution is obtained for the problem of heat conduction through the collector wall under the Cauchy boundary conditions with regard for internal heat sources due to the solar energy flux. A schematic of an experimental setup involving a Solahart solar collector is presented, in which solar radiation heats a heat-transfer medium flowing by gravity. The observed temperatures of the heat-transfer medium at the collector outlet agree satisfactorily with those calculated within the proposed model.