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A numerical study of helium-heated inorganic membrane reformer coupling to HTGR

YIN Huaqiang, JIANG Shengyao, JU Huaiming, ZHANG Youjie

《能源前沿(英文)》 2007年 第1卷 第4期   页码 446-450 doi: 10.1007/s11708-007-0065-3

摘要: Based on one-dimensional quasi-homogeneous model, a steady-state model and its computer program were developed for helium-heated inorganic membrane reformer coupling to high temperature gas-cooled reactor (HTGR). The results show

关键词: temperature gas-cooled     one-dimensional quasi-homogeneous     steady-state     helium-heated    

Comparison of combustion characteristics of petroleum coke and coal in one-dimensional furnace

Qulan ZHOU, Qinxin ZHAO, Guangjie ZHOU, Huiqing WANG, Tongmo XU, Shien HUI,

《能源前沿(英文)》 2010年 第4卷 第3期   页码 436-442 doi: 10.1007/s11708-009-0059-0

摘要: The effect of primary air fraction , outer secondary air swirl strength and excess oxygen coefficient on the combustion characteristics of petroleum coke, Hejin lean coal and Shenmu soft coal are researched on a one-dimensional furnace using a dual channel swirl burner. The results show that with the increase in primary air fraction , the NO emission concentrations of both Hejin lean coal and petroleum coke increase, and the combustion worsens in the earlier stage, but the burn-out rate of Shenmu soft coal is improved. The NO emission concentration obtains a minimum value with an increase in . The ignition and burn-out rate of petroleum coke and Shenmu soft coal are optimal when Ω is minimum and Ω=0.87, respectively. However, both the NO emission concentration of petroleum coke and Shenmu soft coal are minimum when Ω=1.08. The increase in excess oxygen coefficient delays the ignition of petroleum coke, worsens the combustion condition and increases the NO emission concentration, but it greatly decreases the NO emission concentration of Shenmu soft coal.

关键词: petroleum coke     Shenmu soft coal     Hejin lean coal     combustion characteristics     experimental research    

Fictitious soil pile model for dynamic analysis of pipe piles under high-strain conditions

《结构与土木工程前沿(英文)》   页码 915-934 doi: 10.1007/s11709-023-0907-8

摘要: A fictitious soil pile (FSP) model is developed to simulate the behavior of pipe piles with soil plugs undergoing high-strain dynamic impact loading. The developed model simulates the base soil with a fictitious hollow pile fully filled with a soil plug extending at a cone angle from the pile toe to the bedrock. The friction on the outside and inside of the pile walls is distinguished using different shaft models, and the propagation of stress waves in the base soil and soil plug is considered. The motions of the pile−soil system are solved by discretizing them into spring-mass model based on the finite difference method. Comparisons of the predictions of the proposed model and conventional numerical models, as well as measurements for pipe piles in field tests subjected to impact loading, validate the accuracy of the proposed model. A parametric analysis is conducted to illustrate the influence of the model parameters on the pile dynamic response. Finally, the effective length of the FSP is proposed to approximate the affected soil zone below the pipe pile toe, and some guidance is provided for the selection of the model parameters.

关键词: fictitious soil pile     soil plug     pipe piles     high-strain dynamic analysis     one-dimensional wave theory     pile dynamics    

基于一维纳米结构阵列的质子交换膜燃料电池电极设计的研究进展 Review

杜尚峰

《工程(英文)》 2021年 第7卷 第1期   页码 33-49 doi: 10.1016/j.eng.2020.09.014

摘要:

一维(1D)铂基电催化剂对氧还原反应(ORR)展现出了良好的催化活性和稳定性。基于一维铂基纳米结构阵列的三维(3D)有序电极的研究进展表明,它们在解决现有铂/碳(Pt/C)纳米颗粒电极在高性能质子交换膜燃料电池(PEMFC)的传质特性和持久性挑战方面具有巨大的潜力。本文综述了该领域的最新进展,重点介绍了基于独立的铂纳米线阵列的三维有序结构电极,讨论了纳米结构薄膜(NSTF)催化剂以及沉积在聚合物纳米线、碳和二氧化钛纳米管阵列上的铂基纳米颗粒电极,并回顾了铂基纳米管阵列电极的研究进展。本文指出了一维催化剂纳米结构的尺寸、表面性质和分配控制的重要性。最后,讨论了一维纳米结构阵列电极在增大电化学比表面积(ECSA)和氧传质阻力定量研究方面面临的挑战和未来的发展机遇。

关键词: 质子交换膜燃料电池(PEMFC)     电极     一维(1D)     氧还原反应(ORR)     催化剂     有序化    

One-dimensional consolidation of over-consolidated soil under time-dependent loading

XIE Kanghe, WANG Kun, CHEN Guohong, HU Anfeng

《结构与土木工程前沿(英文)》 2008年 第2卷 第1期   页码 67-72 doi: 10.1007/s11709-008-0009-7

摘要: The problem of one-dimensional consolidation of over-consolidated saturated soil under time-dependent loading was studied based on semi-analytical method. The relevant computer code was developed by FORTRAN programming, and one-dimensional consolidation behavior of over-consolidated soil was investigated. It is shown that, unlike this described by traditional Terzaghi’s consolidation theory, the rate of excess pore water pressure dissipation is different from that of settlement developing. The magnitude of load and that of pre-consolidation pressure as well as the loading rate has all significant influence on consolidation. With the increasing of pre-consolidation pressure and loading rate, the rate of consolidation increases correspondingly. However, an increase in load will slow down the consolidation rate.

关键词: different     FORTRAN programming     Terzaghi ’     pre-consolidation     magnitude    

Simplified analytical solution for free vibration characteristics of Hardfill dam

XIAO Wei, HE Yunlong, ZHANG Yanfeng

《结构与土木工程前沿(英文)》 2008年 第2卷 第3期   页码 219-225 doi: 10.1007/s11709-008-0037-3

摘要: Formulas for computing natural frequencies and modes of Hardfill dams are derived based on one-dimensional shear wedge theory, in which the influences of the upstream concrete face and hydrodynamic pressure of water on the dams’ natural frequencies and modes are discussed. Furthermore, the seismic responses of Hardfill dams are calculated using response spectrum method. An example is analyzed to compare the differences of natural frequencies and modes between shear wedge method and FEM. Then the applicability and accuracy of shear wedge method to analyze free vibration characteristics of Hardfill dams are proven.

关键词: upstream concrete     hydrodynamic pressure     vibration     one-dimensional     applicability    

Experimental study for the stratified to slug flow regime transition mechanism of gas-oil two-phase flow in horizontal pipe

LIU Yiping, YANG Weilin, WANG Jing

《能源前沿(英文)》 2008年 第2卷 第2期   页码 152-157 doi: 10.1007/s11708-008-0012-7

摘要: Theoretical relations that predict the transition from a stratified pattern to a slug pattern, including a one-dimensional wave model that contains less empiricism than the commonly used Taitel-Dukler model, and the ideal model for stratified flow for the gas-liquid flow in horizontal pipes are presented. Superficial velocities of each phase, as the onset of slugging occurs, were predicted, and theoretical analysis was conducted on the stratified to slug flow regime transition. The friction, existing between the fluid and pipe wall, and on the interface of two phases, was especially taken into account. A theoretical model was applied to an experiment about air-oil two-phase flow in a 50 mm horizontal pipe. The effect of pipe diameter on the transition was also studied. The results show that this approach gives a reasonable prediction over the whole range of flow rates, and better agreement has been achieved between predicted and measured critical parameters.

关键词: two-phase     Superficial     reasonable prediction     one-dimensional     gas-liquid    

Modeling and simulation of biomass air-steam gasification in a fluidized bed

KONG Xiaoying, WU Chuangzhi, YUAN Zhenhong, MA Longlong, CHANG Jie, LÜ Pengmei

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 209-213 doi: 10.1007/s11705-008-0039-7

摘要: By considering the features of fluidized-bed reactors and the kinetic mechanism of biomass gasification, a steady-state, isothermal, one-dimensional and two-phase mathematical model of biomass gasification kinetics in bubbling fluidized beds was developed. The model assumes the existence of two phases – a bubble and an emulsion phase – with chemical reactions occurring in both phases. The axial gas dispersion in the two phases is accounted for and the pyrolysis of biomass is taken to be instantaneous. The char and gas species CO, CO, H, HO, CH and 8 chemical reactions are included in the model. The mathematical model belongs to a typical boundary value problem of ordinary differential equations and its solution is obtained by a Matlab program. Utilizing wood powder as the feedstock, the calculated data show satisfactory agreement with experimental results and proves the effectiveness and reliability of the model.

关键词: satisfactory agreement     two-phase mathematical     one-dimensional     pyrolysis     calculated    

Simulation of cottonseed cake melt flow in metering zone of a single screw extruder

Hong HE, Jianguo ZHOU,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 263-269 doi: 10.1007/s11705-009-0276-4

摘要: Research on the extrusion of natural polymers (food, feed, etc.) is relatively new due to the complex physicochemical transformations of raw materials, although plastics melt conveying and transport have been well studied. The structure and composition, rheological behavior as well as extrusion processing of natural polymer are much more complicated. In this study, a quasi-three-dimensional (3D) fluid flow model for non-Newtonian, non-isothermal and undeveloped temperature was developed, the model prediction being in reasonably good agreement with the experiment. Results show that the influence of moisture content, among other process variables, is the most significant, followed by screw speed. Some interaction exists between these two variables and the screw speed effect becomes marginal at high moisture contents. In addition, viscosity change in the channel was studied.

关键词: quasi-three-dimensional     rheological     viscosity     processing     influence    

Free vibration analysis of cracked thin plates by quasi-convex coupled isogeometric-meshfree method

Hanjie ZHANG,Junzhao WU,Dongdong WANG

《结构与土木工程前沿(英文)》 2015年 第9卷 第4期   页码 405-419 doi: 10.1007/s11709-015-0310-1

摘要: The free vibration analysis of cracked thin plates via a quasi-convex coupled isogeometric-meshfree method is presented. This formulation employs the consistently coupled isogeometric-meshfree strategy where a mixed basis vector of the convex B-splines is used to impose the consistency conditions throughout the whole problem domain. Meanwhile, the rigid body modes related to the mixed basis vector and reproducing conditions are also discussed. The mixed basis vector simultaneously offers the consistent isogeometric-meshfree coupling in the coupled region and the quasi-convex property for the meshfree shape functions in the meshfree region, which is particularly attractive for the vibration analysis. The quasi-convex meshfree shape functions mimic the isogeometric basis function as well as offer the meshfree nodal arrangement flexibility. Subsequently, this approach is exploited to study the free vibration analysis of cracked plates, in which the plate geometry is exactly represented by the isogeometric basis functions, while the cracks are discretized by meshfree nodes and highly smoothing approximation is invoked in the rest of the problem domain. The efficacy of the present method is illustrated through several numerical examples.

关键词: meshfree method     isogeometric analysis     quasi-convex isogeometric-meshfree method     free vibration     cracked thin plate    

Effect of a less permeable stronger soil layer on the stability of non-homogeneous unsaturated slopes

Nabarun DEY, Aniruddha SENGUPTA

《结构与土木工程前沿(英文)》 2020年 第14卷 第6期   页码 1462-1475 doi: 10.1007/s11709-020-0674-8

摘要: Slope failure occurs due to an increase in the saturation level and a subsequent decrease in matric suction in unsaturated soil. This paper presents the results of a series of centrifuge experiments and numerical analyses on a 55° inclined unsaturated sandy slope with less permeable, stronger silty sand layer inclusion within it. It is observed that a less permeable, stronger silty sand layer in an otherwise homogeneous sandy soil slope hinders the infiltration of water. The water content of the slope just above the stronger layer increases significantly, compared to elsewhere. No shear band is found to initiate in a homogeneous sandy soil slope, whereas for a non-homogeneous slope, they initiate just above the less pervious, stronger layer. A discontinuity of the shear zone is also observed for the case of a non-homogeneous soil slope. The factor of safety of a non-homogeneous, unsaturated soil slope decreases because of the less permeable, stronger layer. It decreases significantly if this less permeable, stronger soil layer is located near the toe of the slope.

关键词: non-homogeneous slope     stronger soil layer     factor of safety     centrifuge model test     unsaturated soils    

Control of homogeneous charge compression ignition combustion in a two-cylinder gasoline direct injection

WANG Zhi, WANG Jianxin, SHUAI Shijin, MA Qingjun, TIAN Guohong

《能源前沿(英文)》 2007年 第1卷 第3期   页码 311-315 doi: 10.1007/s11708-007-0045-3

摘要: Homogeneous charge compression ignition (HCCI) has challenges in ignition timing control, combustion rate control, and operating range extension. In this paper, HCCI combustion was studied in a two-cylinder gasoline direct injection (GDI) engine with negative valve overlap (NVO). A two-stage gasoline direct injection strategy combined with negative valve overlap was used to control mixture formation and combustion. The gasoline engine could be operated in HCCI combustion mode at a speed range of 800–2 200 r/min and load, indicated mean effective pressure (IMEP) range of 0.1–0.53 MPa. The engine fuel consumption is below 240 g/(kW

关键词: Homogeneous     control     combustion     consumption     extension    

埋地热油管道运行参数的准周期变化

崔慧

《中国工程科学》 2006年 第8卷 第1期   页码 51-53

摘要:

从理论上分析了在大气温度变化的影响下埋地热油管道的运行参数以及周围土壤环境均随季节变化而呈现准周期变化规律,在分析大量实际运行数据的基础上,进一步验证了该规律的合理性,建议在有关管道的节能降耗、优化运行以及经济清蜡等问题的研究中,应该考虑运行参数的滞后影响。

关键词: 热油管道     大气温度     土壤环境     准周期    

Rare-earth separation based on the differences of ionic magnetic moment via quasi-liquid strategy

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1584-1594 doi: 10.1007/s11705-022-2189-4

摘要: The separation of rare earth elements is particularly difficult due to their similar physicochemical properties. Based on the tiny differences of ionic radius, solvent extraction has been developed as the “mass method” in industry with hundreds of stages, extremely intensive chemical consumption and large capital investments. The differences of the ionic magnetic moment among rare earths are greater than that of ionic radius. Herein, a novel method based on the large ionic magnetic moment differences of rare earth elements was proposed to promote the separation efficiency. Rare earths were firstly dissolved in the ionic liquid, then the ordering degree of them was improved with the Z-bond effect, and finally the magnetic moment differences between paramagnetic and diamagnetic rare earths in quasi-liquid system were enhanced. Taking the separation of Er/Y, Ho/Y and Er/Ho as examples, the results showed that Er(III) and Ho(III) containing ionic liquids had obvious magnetic response, while ionic liquids containing Y(III) had no response. The separation factors of Er/Y and Ho/Y were achieved at 9.0 and 28.82, respectively. Magnetic separation via quasi-liquid system strategy provides a possibility of the novel, green, and efficient method for rare earth separation.

关键词: rare earth element     different magnetic moment     magnetic separation     ionic liquid    

Liquid discharge plasma for fast biomass liquefaction at mild conditions: The effects of homogeneous

Sen Wang, Shiyun Liu, Danhua Mei, Rusen Zhou, Congcong Jiang, Xianhui Zhang, Zhi Fang, Kostya (Ken) Ostrikov

《化学科学与工程前沿(英文)》 2020年 第14卷 第5期   页码 763-771 doi: 10.1007/s11705-019-1896-y

摘要: Non-thermal plasma exhibits unique advantages in biomass conversion for the sustainable production of higher-value energy carriers. Different homogeneous catalysts are usually required for plasma-enabled biomass liquefaction to achieve time-and energy-efficient conversions. However, the effects of such catalysts on the plasma-assisted liquefaction process and of the plasma on those catalysts have not been thoroughly studied. In this study, an electrical discharge plasma is employed to promote the direct liquefaction of sawdust in a mixture of polyethylene glycol 200 and glycerol. Three commonly used chemicals, sulfuric acid, nitric acid and sodium -toluene sulfate, were selected as catalysts. The effects of the type of catalyst and concentration on the liquefaction yield were examined; further, the roles of the catalysts in the plasma liquefaction process have been discussed. The results showed that the liquefaction yield attains a value of 90% within 5 min when 1% sulfuric acid was employed as the catalyst. Compared with the other catalysts, sulfuric acid presents the highest efficiency for the liquefaction of sawdust. It was observed that hydrogen ions from the catalyst were primarily responsible for the significant thermal effects on the liquefaction system and the generation of large quantities of active species; these effects directly contributed to a higher efficacy of the plasma-enabled liquefaction process.

关键词: discharge plasma     biomass liquefaction     catalyst     homogeneous catalysts    

标题 作者 时间 类型 操作

A numerical study of helium-heated inorganic membrane reformer coupling to HTGR

YIN Huaqiang, JIANG Shengyao, JU Huaiming, ZHANG Youjie

期刊论文

Comparison of combustion characteristics of petroleum coke and coal in one-dimensional furnace

Qulan ZHOU, Qinxin ZHAO, Guangjie ZHOU, Huiqing WANG, Tongmo XU, Shien HUI,

期刊论文

Fictitious soil pile model for dynamic analysis of pipe piles under high-strain conditions

期刊论文

基于一维纳米结构阵列的质子交换膜燃料电池电极设计的研究进展

杜尚峰

期刊论文

One-dimensional consolidation of over-consolidated soil under time-dependent loading

XIE Kanghe, WANG Kun, CHEN Guohong, HU Anfeng

期刊论文

Simplified analytical solution for free vibration characteristics of Hardfill dam

XIAO Wei, HE Yunlong, ZHANG Yanfeng

期刊论文

Experimental study for the stratified to slug flow regime transition mechanism of gas-oil two-phase flow in horizontal pipe

LIU Yiping, YANG Weilin, WANG Jing

期刊论文

Modeling and simulation of biomass air-steam gasification in a fluidized bed

KONG Xiaoying, WU Chuangzhi, YUAN Zhenhong, MA Longlong, CHANG Jie, LÜ Pengmei

期刊论文

Simulation of cottonseed cake melt flow in metering zone of a single screw extruder

Hong HE, Jianguo ZHOU,

期刊论文

Free vibration analysis of cracked thin plates by quasi-convex coupled isogeometric-meshfree method

Hanjie ZHANG,Junzhao WU,Dongdong WANG

期刊论文

Effect of a less permeable stronger soil layer on the stability of non-homogeneous unsaturated slopes

Nabarun DEY, Aniruddha SENGUPTA

期刊论文

Control of homogeneous charge compression ignition combustion in a two-cylinder gasoline direct injection

WANG Zhi, WANG Jianxin, SHUAI Shijin, MA Qingjun, TIAN Guohong

期刊论文

埋地热油管道运行参数的准周期变化

崔慧

期刊论文

Rare-earth separation based on the differences of ionic magnetic moment via quasi-liquid strategy

期刊论文

Liquid discharge plasma for fast biomass liquefaction at mild conditions: The effects of homogeneous

Sen Wang, Shiyun Liu, Danhua Mei, Rusen Zhou, Congcong Jiang, Xianhui Zhang, Zhi Fang, Kostya (Ken) Ostrikov

期刊论文