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Preparation of TiO_2-MoO_3 nano-composite photo-catalyst by supercritical fluid dry method 被引量:6
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作者 ZHANGJing-chang LIQing CAOWei-liang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第2期350-352,共3页
A series of TiO 2-MoO 3 nano-composite photocatalysts were prepared by supercritical fluid dry method(SCFD) and an impregnation technique with TiCl 4 and (NH 4) 6Mo 7O 24 ·4H 2O as the starting materia... A series of TiO 2-MoO 3 nano-composite photocatalysts were prepared by supercritical fluid dry method(SCFD) and an impregnation technique with TiCl 4 and (NH 4) 6Mo 7O 24 ·4H 2O as the starting materials. The catalysts were characterized by the means of XRD, TEM and UV-Vis. Methyl orange was used as model compound for the evaluation of their catalytic activities. The results indicated that the photo-catalyst prepared by SCFD had the advantages of small size(12.84 nm), narrow distribution and good dispersivity. The presence of small amount of Mo in composite catalyst gives rise to the red shift of its absorbance wavelength, decrease of its energy gap and increase of the utility of visible light. Furthermore, higher surface acidity of the photo-catalyst was obtained as the result of the addition of MoO 3. Compared with pure TiO 2, the catalytic activity of the TiO 2-MoO 3 nano-composite photo-catalyst was improved significantly. As the doping concentration of the composite catalysts was controlled at 0.6%(molar percentage), 100% degradation of methyl orange was achieved with in 1.2 h irradiation time. 展开更多
关键词 TiO 2 MoO 3 PHOTOCATALYTIC supercritical fluid dry method
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Synthesis of Ti-Ce-Si Binary and Ternary Nanocomposite Photocatalyst by Supercritical Fluid Drying Technology 被引量:2
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作者 张敬畅 高玲玲 曹维良 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第2期182-187,共6页
Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce(NO3)3·6H2O as precursors by supercritical fluid drying ... Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce(NO3)3·6H2O as precursors by supercritical fluid drying (SCFD) technology. The catalysts were characterized by means of XRD and TEM. The particle size of nanocomposite oxide photocatalysts synthesized by SCFD method is about 6 - 11 nm, which is smaller than those obtained by common drying method (CD). The phase transformation from anatase to rutile was inhibited by SCFD technology. The peaks of SiO2 and CeO2 in XRD patterns indicate that a SiO2 amorphorous phase exists in all the samples and CeO2 is well dispersed on the surface of TiO2. The orthogonal test was designed to optimize the preparing conditions. It is found that ceria dop;.ng enhances the photocatalyric activity markedly, and the optimum doping of CeO2 is 0.1%. The thermal stability of photocatalyst can be improved ; the growth of particle-size and the decrease of surface area can be prohibited by doping of SlOe. Heat-treatment is a necessary factor to induce chemistry change of Ti-Si surface. The optimum heat-treating temperature is 600℃. A novel and efficient Ti-Ce-Si ternary nanocomposite was prepared by SCFI) method with strong thermal stability and high photoactivity in the photodegratation of phenol. 展开更多
关键词 TITANIA SILICA CERIA nanocomposite photocatalysts supercritical fluid dried rare earths
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Synthesis and Characterization of TiO_2-CeO_2 Nanocomposite by Supercritical Fluid Drying 被引量:2
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作者 张敬畅 高玲玲 曹维良 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第S1期134-137,共4页
TiO_2-CeO_2 nanocomposite particles were prepared with Ce(NO_3)_3·6H_2O and TiCl_4 as precursors by the codeposition method and supercritical fluid drying (SCFD) technology. The particles prepared were characteri... TiO_2-CeO_2 nanocomposite particles were prepared with Ce(NO_3)_3·6H_2O and TiCl_4 as precursors by the codeposition method and supercritical fluid drying (SCFD) technology. The particles prepared were characterized by means of XRD, TEM and FTIR. The results show that SCFD can give rise to the direct synthesis of the anatase TiO_2-CeO_2,and the particle size is 6~11 nm under 500 ℃ thermal-treated,smaller than that by common drying (CD). The phase transformation from anatase to rutile is inhibited by supercritical fluid drying technology. The peak of CeO_2 is not observed in XRD patterns,Ce-O band vibration was present in FTIR spectrum,which indicates that CeO_2 is well dispersed on the surface of TiO_2. 展开更多
关键词 TITANIA CERIA supercritical fluid dried NANOCOMPOSITE rare earths
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Preparation of (Ti, Sn)O_2 Nano-Composite Photocatalyst by Supercritical Fluid Dry Combination Technology 被引量:1
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作者 Jingchang ZHANG, Qing LI and Weiliang CAO Institute of Modern Catalysis, The Key Laboratory of Science and Technology of Controllable Chemical Reactions, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2005年第2期191-195,共5页
A series of TiO2-SnO2 nano-sized composite photo-catalysts containing Sn (9.3%-30.1%) were prepared from TiCI4 and SnCl4·5H2O by using sol-gel, supercritical fluid dry and solid-phase reaction (SCFD) combination ... A series of TiO2-SnO2 nano-sized composite photo-catalysts containing Sn (9.3%-30.1%) were prepared from TiCI4 and SnCl4·5H2O by using sol-gel, supercritical fluid dry and solid-phase reaction (SCFD) combination technology. Characterizations with X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR) showed that, in addition to anatase type TiO2, a new active phase (Ti, Sn)O2 (with particle size of 2.0-4.3 nm) formed, and there were no SnO2 crystals observed in the range of the doping concentration studied. Photo-catalytic reaction of phenol was used as a model reaction to evaluate the catalytic activities of the obtained catalysts. Compared with pure TiO2 or Ti-Sn catalyst prepared with general sol-gel method, Ti-Sn nano-composite photo-catalyst thus obtained showed significant improvement in catalytic activity. The photo-catalytic degradation rate of phenol could reach as high as 93.5% after 7 h. The preparation conditions of the new phase (Ti, Sn)O2 were investigated and its catalytic mechanism was proposed. The photo-catalytic particles prepared using SCFD combination technology exhibited small particle size, large surface area and high activity. 展开更多
关键词 Anatase TiO2 (Ti Sn)O2 Photo-catalytic Supercritical fluid dry method Solid-phase reaction
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复杂边界条件下液体管路球阀流致振动建模及特性分析
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作者 孙燕 尹莎莎 +3 位作者 靳国永 靳淼 孙凯浪 叶天贵 《船舶力学》 北大核心 2025年第2期321-335,共15页
球阀流致振动是液体管路系统振动噪声的主要来源之一,掌握球阀流致振动特性是液体管路系统振动噪声分析、低噪声设计及控制的关键前提。本文以球阀为研究对象,采用三向弹簧与梁单元模型模拟球阀进出口法兰端面弹性边界条件,以实测干湿... 球阀流致振动是液体管路系统振动噪声的主要来源之一,掌握球阀流致振动特性是液体管路系统振动噪声分析、低噪声设计及控制的关键前提。本文以球阀为研究对象,采用三向弹簧与梁单元模型模拟球阀进出口法兰端面弹性边界条件,以实测干湿模态数据为基准进行边界约束刚度反演与修正,建立实际安装条件下球阀边界约束模型。在此基础上,基于有限元方法和计算流体力学理论进一步建立球阀流致振动计算模型,研究不同质量流量与不同开度瞬态工况下球阀流场与结构振动特性。结果表明:采用三向弹簧与梁单元模型能够较好地模拟液体管路球阀实际安装边界条件;随着球阀开度减小或质量流量增加,流场的扰动更加明显,各测点位置的振动加速度级均有所增大。 展开更多
关键词 球阀 流致振动 约束边界 干湿模态
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EcoDry污泥干燥技术在欧洲的应用 被引量:2
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作者 周玉文 胡伟 +1 位作者 John Kerbbers Helmut G Hohnecker 《给水排水》 CSCD 北大核心 2009年第8期36-39,共4页
EcoDry工艺是一种以污泥粒渣为燃料的新型污泥干燥技术,分析了该工艺的原理、特性、优缺点,着重介绍其在德国Obrigheim污水处理厂和匈牙利Pecs污水处理厂扩建工程中的应用,并对运行结果和排放标准进行了比较。研究结果表明,EcoDry工艺... EcoDry工艺是一种以污泥粒渣为燃料的新型污泥干燥技术,分析了该工艺的原理、特性、优缺点,着重介绍其在德国Obrigheim污水处理厂和匈牙利Pecs污水处理厂扩建工程中的应用,并对运行结果和排放标准进行了比较。研究结果表明,EcoDry工艺的干污泥和废气排放符合欧盟标准,可以为我国新建、扩建现有污泥干燥处置系统提供参考。 展开更多
关键词 Ecodry 污泥干化 流化床干燥机 转鼓式干燥机 欧盟标准 污水处理厂
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CO_(2)压裂液的研究进展、挑战与未来展望
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作者 张舵 《科技创新与应用》 2025年第2期106-109,共4页
水基压裂液污染环境,水资源浪费严重,甚至引发液相圈闭等,而CO_(2)压裂液可有效规避此类弊端。该文综述3种CO_(2)压裂液的基础研究进展,分析其在油气田现场的应用效果,指出其在工业化应用过程中所面临的挑战,并对其未来的研究方向提出... 水基压裂液污染环境,水资源浪费严重,甚至引发液相圈闭等,而CO_(2)压裂液可有效规避此类弊端。该文综述3种CO_(2)压裂液的基础研究进展,分析其在油气田现场的应用效果,指出其在工业化应用过程中所面临的挑战,并对其未来的研究方向提出相关建议。 展开更多
关键词 CO_(2)干法压裂液 CO_(2)泡沫压裂液 超临界CO_(2)压裂液 应用效果 研究方向
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基于神经网络和CFD的规整填料塔流体力学计算
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作者 李邢 曾爱武 《化学工业与工程》 北大核心 2025年第1期130-137,共8页
提出一种结合计算流体力学(CFD)和BP(Back Propagation)人工神经网络的多尺度计算方法,计算规整填料塔上的流体力学行为。根据最小特征单元实际尺寸建立小尺度三维CFD模型,研究了填料塔单气相和气液两相流体流动分布方式,弥补了在研究... 提出一种结合计算流体力学(CFD)和BP(Back Propagation)人工神经网络的多尺度计算方法,计算规整填料塔上的流体力学行为。根据最小特征单元实际尺寸建立小尺度三维CFD模型,研究了填料塔单气相和气液两相流体流动分布方式,弥补了在研究塔壁单元和层间转换单元产生压降方面的缺陷。建立了结点网络模型,计算全塔的流体分布等宏观信息。以CFD计算收集到的数据集训练了2组神经网络模型,分别以结点流量为输入计算干塔压降和持液量。计算结果与相关实验数据比较,干塔压降计算模型的平均相对偏差为8.63%,最大相对偏差为14.02%。持液量计算模型的平均相对偏差约为9.63%,最大相对偏差为13.97%。这表明该训练好的人工神经网络模型具备较好的预测能力,结果较为可信。 展开更多
关键词 规整填料 计算流体力学 BP神经网络 干塔压降 持液量
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Solidworks Flow Simulation在干燥箱设计中的仿真分析和应用
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作者 侯彦凯 李鹏 +1 位作者 孙建军 周文健 《煤炭加工与综合利用》 2025年第1期20-23,共4页
干燥箱是煤炭全水分测定中制样的核心设备,针对新设计的干燥箱缺乏实际工况验证,需要结合现场应用情况进行优化的问题,提出了通过Solidworks Flow Simulation对干燥箱的整体结构进行流体仿真分析,力求缩短干燥箱的生命设计周期,减小成... 干燥箱是煤炭全水分测定中制样的核心设备,针对新设计的干燥箱缺乏实际工况验证,需要结合现场应用情况进行优化的问题,提出了通过Solidworks Flow Simulation对干燥箱的整体结构进行流体仿真分析,力求缩短干燥箱的生命设计周期,减小成本投入,达到最优的设计效果,根据仿真结果,对干燥箱的结构,尤其对其中的风道结构进行了调整,并再次根据新的风道结构,进行了仿真验证,证明了结构的可靠性。 展开更多
关键词 干燥箱 风道结构 流体仿真分析 仿真验证
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Drying Drop Technology as a Possible Tool for Detection Leukemia and Tuberculosis in Cattle 被引量:1
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作者 Tatiana A. Yakhno Anatoly A. Sanin +6 位作者 Robert G. Ilyazov Gulusa V. Vildanova Rafat A. Khamzin Nadezhda P. Astascheva Mikhail G. Markovsky Vadim D. Bashirov Vladimir G. Yakhno 《Journal of Biomedical Science and Engineering》 2015年第1期1-23,共23页
Usual response of organism to viral or bacterial invasion represents antibodies production, qualitative and quantitative changes in composition of biological fluids. These changes influence conformation and surface ch... Usual response of organism to viral or bacterial invasion represents antibodies production, qualitative and quantitative changes in composition of biological fluids. These changes influence conformation and surface characteristics of macromolecules (proteins), which become apparent in sessile drying drops, when they form aggregates due to salting-out effect and sediment. The bottom adsorption layers change their adhesive and viscoelastic properties in time depending on fluid composition and structure. The aim of this study was verification the idea of using this phenomenon in rapid vet diagnostics. Milk, blood and serum samples of 183 cows were tested using Drop Drying Technology (DDT). A drop of tested fluid dried on a polished quartz plate, oscillated with constant frequency—60 kHz. Mechanical properties of the drop changed during drying, influenced the electrical conductivity of the quartz plate. This signal was converted to the Acoustical- Mechanical Impedance (AMI) and displayed as a curve in coordinates AMI vs. Time. Shape of the AMI curve reflected this dynamics, and was used as a target for quantitative comparison between control and infected animals. Frequency analysis of the estimated parameters of the curves was performed using features of the Excel program. Powerful method of artificial neural network processing of the experimental data was also tested in this work as a possible tool for future development. Significant differences between control, Bovine leucosis virus positive (BLV+) and Bovine tuberculin positive (BTub+) cattle groups were obtained using all biological fluids—blood, serum and milk. We fixed also a season shift of the data, but distinction between groups still remained. In serum and milk some features of the AMI curves were more stable, and retained diagnostic properties when combined winter and spring databases. Further development of DDT is proposed. 展开更多
关键词 Sessile dryING DROPS Biological fluids Dynamics of Mechanical Properties Acoustical Impedancemetry VET Diagnostics
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The Inferior Vena Cava Diameter as a Marker of Dry Weight in Chronic Hemodialyzed Patients
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作者 Yasuhiro Ando Satoru Yanagiba Yasushi Asano 《中国血液净化》 2002年第9期3-4,共2页
We have previously reported that the diameter of the inferior vena cava(IVC) reflects the amount of body fluid in hemodialyzed (HD) patients. The present study was undertaken to depict the criteria of IVC diameters fo... We have previously reported that the diameter of the inferior vena cava(IVC) reflects the amount of body fluid in hemodialyzed (HD) patients. The present study was undertaken to depict the criteria of IVC diameters for determining dry weight (DW) in anuric HD patients. In healthy subjects, the maximal diameters during quiet expiration (IVCe) and the minimal diameters during quiet inspiration (IVCi) were (16.7±3.2) and (5.7±5.4)mm,respectively (mean±SD).The collapsibility index (CI,1-IVCi/IVCe), which inversely correlates with the central venous pressure,was 0.68±0.29. In anuric HD patients,the IVCe/CI values before and after HD were 14.9±3.2/0.68±0.24 and 8.2±2.3/0.94±0.09, respectively. IVCe decreased proportionally to the amount of ultrafiltration. In HD patients with hypervolemic pulmonary edema, the IVCe and CI values were 22.4±2.9 and 0.22±0.11, respectively. We proposed that IVCe/CI after HD is (8±3)mm/0.9 ± 0.1 as the markers of DW in anuric HD patients and that an IVCe value≥22mm together with a CI≤0.22 implies the warning level of body fluid retention. 展开更多
关键词 HEMODIALYSIS ULTRASONOGRAPHY Inferior vena cava dry weight Body fluid volume.
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蒸汽烫漂与热风干燥箱流场优化设计及仿真
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作者 陈忠加 赵宇轩 +2 位作者 卢丰源 孙敏 王青春 《农业工程学报》 EI CAS CSCD 北大核心 2024年第6期60-71,共12页
农产品的烫漂与干燥是农产品加工的关键技术。农产品蒸汽烫漂与热风干燥箱是集烫漂与干燥一体的新型农产品绿色保质低碳智能干燥技术装备。农产品蒸汽烫漂与热风干燥箱内部流场均匀性直接影响着农产品烫漂与干燥效果。为提高其内部速度... 农产品的烫漂与干燥是农产品加工的关键技术。农产品蒸汽烫漂与热风干燥箱是集烫漂与干燥一体的新型农产品绿色保质低碳智能干燥技术装备。农产品蒸汽烫漂与热风干燥箱内部流场均匀性直接影响着农产品烫漂与干燥效果。为提高其内部速度均匀性与温湿度均匀性,同时减少冷凝现象发生,采用计算流体力学(computational fluid dynamics,CFD)方法建立蒸汽烫漂与热风干燥箱模型,对其送风方式和送风口数量进行研究。结果表明:侧送侧回的送风方式在速度场以及温湿度场的均匀性总体优于上送下回,能量利用系数提高约18%,箱内壁面冷凝面积小于上送下回。仿真研究表明,当送风口数量为4个时,箱内的温度场和相对湿度场均匀性更好,能量利用系数最高。试验表明,蒸汽烫漂与热风干燥箱的试验值和仿真值最大温度偏差为2.3℃,相对湿度误差不超过1.3%,误差在合理范围内,仿真结果可靠,研究结果可为农产品低碳智能干燥新技术的研究提供参考。 展开更多
关键词 农产品 干燥设备 蒸汽烫漂 热风干燥 计算流体力学
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An Energy Production System Powered by Solar Heat with Biogas Dry Reforming Reactor and Solid Oxide Fuel Cell
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作者 Akira Nishimura Ryotaro Sato Eric Hu 《Smart Grid and Renewable Energy》 CAS 2023年第5期85-106,共22页
In this paper, an energy system consisting of solar collector, biogas dry reforming reactor and solid oxide fuel cell (SOFC) has been proposed. The heat produced from the concentrating solar collector is used to drive... In this paper, an energy system consisting of solar collector, biogas dry reforming reactor and solid oxide fuel cell (SOFC) has been proposed. The heat produced from the concentrating solar collector is used to drive a biogas dry reforming reactor in order to produce H<sub>2</sub> as a fuel for SOFC, in such as system. The aim of this study is to clarify the impact of climate data on the performance of solar collector with various sizes/designs. The temperature of heat transfer fluid produced by the solar collector is calculated by adopting the climate data for Nagoya city in Japan in 2021. The amount of H<sub>2</sub> produced from the biogas dry reforming reactor and the power generated by SOFC were simulated. The results show the temperature of heat transfer fluid (T<sub>fb</sub>) and T<sub>fb</sub> ratio (a) based on the length of absorber (dx) = 1 m have a peak near the noon following the trend of solar intensity (I). Results also revealed that a increases with increase in dx. It is found that the differences of T<sub>fb</sub> and a between dx = 2 m and dx = 3 m are larger than those between dx = 1 m and dx = 2 m. It is revealed that T<sub>fb</sub> and a are higher in spring and summer. dx = 4 m is the optimum length of solar absorber. The amount of H<sub>2</sub> produced from the biogas dry reforming reactor as well as the power generated by SOFC is the highest in August, resulting that it is prefer to produce H<sub>2</sub> and to generate SOFC in summer. 展开更多
关键词 Solar Collector fluid Temperature Climate Data Biogas dry Reforming H2 Production SOFC
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基于Workbench的瑞利台阶干气密封流固耦合分析
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作者 张伟政 任娅南 +1 位作者 韩东民 姜娥 《甘肃科学学报》 2024年第5期96-103,共8页
为了研究瑞利台阶在干气密封中的性能表现,建立了瑞利台阶干气密封计算模型,采用Workbench流-固耦合分析模块对动、静环在整体气膜作用下的受力与变形进行模拟计算,探究了不同工况参数和密封环材料对动、静环的变形及应力影响规律。结... 为了研究瑞利台阶在干气密封中的性能表现,建立了瑞利台阶干气密封计算模型,采用Workbench流-固耦合分析模块对动、静环在整体气膜作用下的受力与变形进行模拟计算,探究了不同工况参数和密封环材料对动、静环的变形及应力影响规律。结果表明:在槽根处的气膜压力最大,形成的动压效应最强,气膜力也较大,故动、静环的最大应力和形变均位于槽根处。在入口压力和旋转速度增大时,气膜力也会随之增大,从而使动、静环的应力值和形变量增大。动环材料相对于静环材料有更高的弹性模量,所以动环的应力变化相对于静环要更大,而较大应力变化有利于抵消流体力耦合引起的变形应力,进而达到减小密封环变形的目的。 展开更多
关键词 瑞利台阶 干气密封 模拟计算 流固耦合
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热泵干燥室的流场模拟及结构优化 被引量:2
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作者 康宏彬 邓先奋 +3 位作者 肖波 王雷 荆磊 盛斌 《农机化研究》 北大核心 2024年第10期15-20,共6页
为解决陈皮在热泵干燥过程中干燥不均匀、效率低等问题,运用计算流体力学(Computational Fluid Dynamics,CFD)对陈皮热泵干燥室的内部气流分布进行模拟仿真,并对导风板的排布方式进行优化模拟仿真分析。研究结果表明:有导风板时,干燥室... 为解决陈皮在热泵干燥过程中干燥不均匀、效率低等问题,运用计算流体力学(Computational Fluid Dynamics,CFD)对陈皮热泵干燥室的内部气流分布进行模拟仿真,并对导风板的排布方式进行优化模拟仿真分析。研究结果表明:有导风板时,干燥室的内部气流分布较均匀;当倾斜角度为30°、侧边间距为80mm、垂直间距为260mm时,能够有效提高陈皮热泵干燥室的气流分布均匀性和干燥效率。 展开更多
关键词 陈皮 热泵干燥室 计算流体力学 流场模拟
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超临界二氧化碳螺旋槽干气密封热流耦合润滑临界阻塞特性研究 被引量:1
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作者 朱芝 许恒杰 +3 位作者 陈维 毛文元 邓强国 孙雪剑 《化工学报》 EI CSCD 北大核心 2024年第2期604-615,共12页
在密封稳定运行的前提下,促成密封端面出口形成阻塞流动以提升气膜开启力、降低端面泄漏不失为干气密封性能优化的有效途径。以超临界二氧化碳(CO_(2))螺旋槽干气密封为研究对象,综合考虑实际气体、离心惯性、湍流和阻塞流效应,采用有... 在密封稳定运行的前提下,促成密封端面出口形成阻塞流动以提升气膜开启力、降低端面泄漏不失为干气密封性能优化的有效途径。以超临界二氧化碳(CO_(2))螺旋槽干气密封为研究对象,综合考虑实际气体、离心惯性、湍流和阻塞流效应,采用有限差分法耦合求解压力和温度控制方程,定性研究了热流耦合润滑下的临界阻塞特性(临界阻塞进口压力po_(cir)、临界阻塞转速N_cir、临界阻塞膜厚h0_cir和阻塞临界失稳膜厚hsc)。结果表明:等温流动和绝热流动模型下超临界CO_(2)干气密封端面间隙出口均存在阻塞发生工况区间,进口压力、膜厚、转速对应的阻塞发生区间分别为po>po_(cir)、h0_cir<h0<hsc和N<N_cir;转速升高可以对临界阻塞进口压力和临界阻塞膜厚产生持续增强作用,增大膜厚则会导致临界阻塞压力降低、临界阻塞转速上升,高压进口将使阻塞零刚度对应的膜厚(阻塞临界失稳膜厚hsc)下行;相较于等温流动假设,气膜热效应对超临界CO_(2)干气密封临界阻塞特性参数的影响程度较为显著,且影响规律各有不同。 展开更多
关键词 超临界二氧化碳 干气密封 热流耦合 临界阻塞特性 阻塞发生区间
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采用干工质的补气增焓高温热泵循环热力学分析
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作者 刘佳昕 陈健勇 +4 位作者 陈颖 罗向龙 梁颖宗 何嘉诚 杨智 《制冷学报》 CAS CSCD 北大核心 2024年第6期41-49,共9页
利用高温热泵回收工业余热具有巨大的节能潜力。高温热泵要求高临界温度,可选工质以干工质居多,但干工质从饱和气相开始压缩时,压缩过程在两相区,带来液击风险,不利于压缩机和高温热泵运行。提出了2种改进的补气增焓热泵循环(循环A和循... 利用高温热泵回收工业余热具有巨大的节能潜力。高温热泵要求高临界温度,可选工质以干工质居多,但干工质从饱和气相开始压缩时,压缩过程在两相区,带来液击风险,不利于压缩机和高温热泵运行。提出了2种改进的补气增焓热泵循环(循环A和循环B),以Isohexane、R1336mzz(Z)和R1233zd(E)为工质,分析了压缩机等熵效率、蒸发温度和冷凝温度对最小过热度及热泵性能的影响。结果表明:对于循环B,蒸发温度自50℃升至80℃,对于R1336mzz(Z),COP最高可提高2.56%,VHC(单位容积制热量,volumetric heating capacity)最高可提高3.18%;对于R1233zd(E),COP最高可提高0.44%,VHC最高可以提高0.54%。循环A对等熵效率的适应性较好;对于循环B,当等熵效率超过0.6时,不宜采用Isohexane作为工质,而当等熵效率超过0.95时,R1336mzz(Z)也不宜采用。 展开更多
关键词 高温热泵 干工质 补气增焓 最小过热度
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高压干气密封三体双向流固耦合模型及端面力变形规律研究
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作者 翁文豪 胡航领 +4 位作者 江锦波 彭旭东 林志民 王林涛 孟祥铠 《摩擦学学报(中英文)》 CSCD 北大核心 2024年第11期1540-1557,共18页
本文中综合考虑影响密封环端面力变形的流体膜压力、密封环结构和环座作用力这3个关键要素及其交互影响,提出了干气密封三体双向流固耦合模型,通过求解湍流修正的雷诺方程获得气膜压力场,并应用ANSYS求解密封环端面力变形,研究了不同结... 本文中综合考虑影响密封环端面力变形的流体膜压力、密封环结构和环座作用力这3个关键要素及其交互影响,提出了干气密封三体双向流固耦合模型,通过求解湍流修正的雷诺方程获得气膜压力场,并应用ANSYS求解密封环端面力变形,研究了不同结构参数和运行工况条件下密封环端面力变形规律,对比分析了3种流固耦合模型以及流态模型、密封环轴向厚度和辅助密封径向位置对密封环端面变形和稳态性能的影响,获得了上述结构参数优选值范围.结果表明:相较于三体双向模型,忽略流体膜与密封环交互影响的三体单向模型和忽略环座作用力的双体双向模型获得的平均膜厚和泄漏率均显著偏小;流态模型选取对密封间隙形状影响不大,但会使平衡膜厚和泄漏率明显偏低;改变静环轴向厚度和动环辅助密封径向位置均会使对应密封环端面变形方向发生变化,且通过与动环轴向厚度和静环辅助密封圈径向位置取值的合理组合,可实现较低泄漏率和近平行间隙的目标. 展开更多
关键词 干气密封 流固耦合 力变形 湍流 数值模拟
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废弃秸秆等生物质低能耗非相变秒级干燥
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作者 张香港 常玉龙 +1 位作者 汪华林 江霞 《化工学报》 EI CSCD 北大核心 2024年第7期2433-2445,F0001,共14页
自主研发并设计搭建了生物质非相变旋流干燥的小试和中试实验装置。小试实验结果表明,在最佳干燥条件下秸秆含水率可从68%降至15%左右,脱水效率可达70%以上,放大规模的实验在中试装置上进行了验证。仿真模拟研究揭示了旋流场内切向、径... 自主研发并设计搭建了生物质非相变旋流干燥的小试和中试实验装置。小试实验结果表明,在最佳干燥条件下秸秆含水率可从68%降至15%左右,脱水效率可达70%以上,放大规模的实验在中试装置上进行了验证。仿真模拟研究揭示了旋流场内切向、径向和轴向速度对固液分离的影响。理论计算结果表明干燥过程脱除的水分中有64.81%以非相变液滴形式脱离,说明非相变在干燥过程中占主要地位。机理研究表明水分可从生物质孔道中分离,这是由于生物质在旋流场中发生自公转耦合运动,导致其表面形成孔道,使水分以微液滴形式脱除。此外还对玉米胚芽、酒糟、木屑等生物质进行了实验,均达到接近70%的脱水效率,证明了该技术对生物质种类的普适性。 展开更多
关键词 生物质 干燥 旋风分离器 计算流体力学 低能耗
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计算流体力学在果蔬干燥领域的研究进展
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作者 李孟卿 耿智化 +2 位作者 朱丽春 张茜 杨旭海 《食品科学》 EI CAS CSCD 北大核心 2024年第6期294-305,共12页
干燥是延长果蔬保质期的主要方法之一。随着计算机技术的发展,计算流体力学在果蔬干燥领域中得到广泛的应用。该技术可以对果蔬干燥过程中的流体流动、传热传质等动力学现象进行模拟和预测,并输出可视化结果。与传统实验相比,计算流体... 干燥是延长果蔬保质期的主要方法之一。随着计算机技术的发展,计算流体力学在果蔬干燥领域中得到广泛的应用。该技术可以对果蔬干燥过程中的流体流动、传热传质等动力学现象进行模拟和预测,并输出可视化结果。与传统实验相比,计算流体力学技术拥有节能、低成本、模拟速度快、灵活度高等优点。本文详细介绍了计算流体力学在果蔬干燥领域的工作原理,并对其在不同果蔬干燥方式中的研究进展进行综述,报道了耦合收缩的数值模型研究进度,并对计算流体力学在果蔬干燥领域的发展方向进行展望,以期为研究者提供新的见解和参考。 展开更多
关键词 计算流体力学 果蔬干燥 模拟 收缩
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