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A study of spray granulation in vibrated fluidized bed with internal heating tubes

Xiaoheng PAN, Shichao YE, Zeguang ZHANG, Li ZHANG, Xuejun ZHU

《化学科学与工程前沿（英文）》 2009年第3卷第1期页码 78-82 doi: 10.1007/s11705-009-0084-x

摘要： The granulation process in a vibrated fluidized bed with immersed horizontal heating tubes was studied in this paper, with small monoammonium phosphate particles as the initial particles and monoammonium phosphate solution sprayed on them. The concrete influences on the granulating performance of the immersed horizontal heating power, fluidizing gas velocity, vibration frequency and amplitude had been analyzed theoretically. The results show that appropriate vibration intensity is a preferred condition for the growth of partials, but the fine dust will become much more along with prolonged vibration. Increasing the heating power is beneficial to raise the growth rate. Particles will grow faster if the fluidizing gas velocity is higher, but this will cause more fine dust. The optimized condition of =0.002 m, =6.67 Hz, =1.4 m/s was given after the analysis of the experimental results. In the end, a semiempirical formula was derived from the experiment data, and the calculation results show good agreement with the experimental data.

关键词： vibrated fluidized bed immersed horizontal horizontal heating tubes spray granulation particle growth model

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Numerical simulation on flow of ice slurry in horizontal straight tube

Shengchun LIU,Ming SONG,Ling HAO,Pengxiao WANG

《能源前沿（英文）》 2021年第15卷第1期页码 201-207 doi: 10.1007/s11708-017-0451-0

摘要： Numerical simulation on flow of ice slurry in horizontal straight tubes was conducted in this paper to improve its transportation characteristics and application. This paper determined the influence of the diameter and length of tubes, the ice packing factors (IPF) and the flow velocity of ice slurry on pressure loss by using numerical simulation, based on two-phase flow and the granular dynamic theory. Furthermore, it was found that the deviation between the simulation results and experimental data could be reduced from 20% to 5% by adjusting the viscosity which was reflected by velocity. This confirmed the reliability of the simulation model. Thus, two mathematical correlations between viscosity and flow velocity were developed eventually. It could also be concluded that future rheological model of ice slurry should be considered in three sections clarified by the flow velocity, which determined the fundamental difference from single-phase fluid.

关键词： ice slurry horizontal tubes numerical simulation pressure drop viscosity model

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High-efficiency inspecting method for mobile robots based on task planning for heat transfer tubes in

《机械工程前沿（英文）》 2023年第18卷第2期 doi: 10.1007/s11465-022-0741-z

摘要： Many heat transfer tubes are distributed on the tube plates of a steam generator that requires periodic inspection by robots. Existing inspection robots are usually involved in issues: Robots with manipulators need complicated installation due to their fixed base; tube mobile robots suffer from low running efficiency because of their structural restricts. Since there are thousands of tubes to be checked, task planning is essential to guarantee the precise, orderly, and efficient inspection process. Most in-service robots check the task tubes using row-by-row and column-by-column planning. This leads to unnecessary inspections, resulting in a long shutdown and affecting the regular operation of a nuclear power plant. Therefore, this paper introduces the structure and control system of a dexterous robot and proposes a task planning method. This method proceeds into three steps: task allocation, base position search, and sequence planning. To allocate the task regions, this method calculates the tool work matrix and proposes a criterion to evaluate a sub-region. And then all tasks contained in the sub-region are considered globally to search the base positions. Lastly, we apply an improved ant colony algorithm for base sequence planning and determine the inspection orders according to the planned path. We validated the optimized algorithm by conducting task planning experiments using our robot on a tube sheet. The results show that the proposed method can accomplish full task coverage with few repetitive or redundant inspections and it increases the efficiency by 33.31% compared to the traditional planning algorithms.

关键词： steam generator transfer tubes mobile robot dexterous structure task planning efficient inspection

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Theoretical study on the confine-stiffening effect and fractal cracking of square concrete filled steel tubes

《结构与土木工程前沿（英文）》 2021年第15卷第6期页码 1317-1336 doi: 10.1007/s11709-021-0763-3

摘要： Tension stress in steel-concrete composite is widely observed in engineering design. Based on an experimental program on tension performance of three square concrete-filled tubes (SCFT), the tension theory of SCFT is proposed using a mechanics-based approach. The tension stiffening effect, the confining strengthening effect and the confining stiffening effect, observed in tests of SCFTs are included in the developed tension theory model. Subsequently, simplified constitutive models of steel and concrete are proposed for the axial tension performance of SCFT. Based on the MSC.MARC software, a special fiber beam-column element is proposed to include the confining effect of SCFTs under tension and verified. The proposed analytical theory, effective formulas, and equivalent constitutive laws are extensively verified against three available tests reported in the literature on both global level (e.g., load-displacement curves) and strain level. The experimental verification proves the accuracy of the proposed theory and formulations in simulating the performance of SCFT members under tension with the capability to accurately predict the tensile strength and stiffness enhancements and realistically simulate the fractal cracking phenomenon.

关键词： square concrete filled tubes confine-stiffening confine-strengthening fractal cracking fracture

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Civil and structural engineering applications, recent trends, research and developments on pultruded fiber reinforced polymer closed sections: a review

Alfred Kofi GAND, Tak-Ming CHAN, James Toby MOTTRAM

《结构与土木工程前沿（英文）》 2013年第7卷第3期页码 227-244 doi: 10.1007/s11709-013-0216-8

摘要： The objectives of this study are to review and evaluate the developments and applications of pultruded fiber-reinforced polymer composites in civil and structural engineering and review advances in research and developments. Several case applications are reviewed. The paper presents a state-of-the-art review of fundamental research on the behavior of pultruded fiber reinforced polymer closed sections and highlights gaps in knowledge and areas of potential further research.

关键词： fibre reinforced polymer composites behaviour of FRPs tubular sections pultruded FRP tubular profiles FRP tubes in bridges applications of pultruded FRP tubes new-build with FRP tubes

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A state-of-the-art review of solar passive building system for heating or cooling purpose

Arun Kumar NANDA,C K PANIGRAHI

《能源前沿（英文）》 2016年第10卷第3期页码 347-354 doi: 10.1007/s11708-016-0403-0

摘要： The major portion of energy in a building is consumed by heating, ventilating, and air-conditioning (HVAC). The traditional heating and cooling systems contribute greatly to the emission of greenhouse gases, especially carbon dioxide. Four different ways, i.e., Trombe wall, solar chimney, unglazed transpired solar façade, and solar roof, are adopted for solar heating. Similarly, two major ways, i.e., evaporative cooling and building integrated evaporative cooling are adopted for cooling of the building. Therefore, an attempt has been made in this paper to compile the developments of solar heating and cooling technologies in a building.

关键词： HVAC heating cooling solar heating carbon dioxide (CO₂) emissions

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A district heating system based on absorption heat exchange with CHP systems

Lin FU, Yan LI, Yi JIANG, Shigang ZHANG,

《能源前沿（英文）》 2010年第4卷第1期页码 77-83 doi: 10.1007/s11708-010-0022-0

摘要： In order to decrease the energy consumption of large-scale district heating systems with cogeneration, a district heating system is presented in this paper based on absorption heat exchange in the cogeneration system named Co-ah cycle, which means that the cogeneration system is based on absorption heat exchange. In substations of the heating system, the temperature of return water of primary heat network is reduced to about 25°C through the absorption heat-exchange units. In the thermal station of the cogeneration plant, return water is heated orderly by the exhaust steam in the condenser, the absorption heat pumps, and the peak load heater. Compared with traditional heating systems, this system runs with a greater circuit temperature drop so that the delivery capacity of the heat network increases dramatically. Moreover, by recovering the exhausted heat from the condensers, the capacity of the district heating system and the energy efficiency of the combined heat and power system (CHP system) are highly developed. Therefore, high energy and economic efficiency can be obtained.

关键词： cogeneration district heating absorption heat exchange Co-ah cycle

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Natural convection heat transfer of water in a horizontal circular gap

SU Guanghui, WU Yingwei, Kenichiro Sugiyama

《能源前沿（英文）》 2007年第1卷第2期页码 167-173 doi: 10.1007/s11708-007-0021-y

摘要： An experimental study on the natural convection heat transfer on a horizontal downward facing heated surface in a water gap was carried out under atmospheric pressure conditions. A total of 700 experimental data points were correlated using Rayleigh versus Nusselt number in various forms, based on different independent variables. The effects of different characteristic lengths and film temperatures were discussed. The results show that the buoyancy force acts as a resistance force for natural convection heat transfer on a downward facing horizontal heated surface in a confined space. For the estimation of the natural convection heat transfer under the present conditions, empirical correlations in which Nusselt number is expressed as a function of the Rayleigh number, or both Rayleigh and Prandtl numbers, may be used. When it is accurately predicted, the Nusselt number is expressed as a function of the Rayleigh and Prandtl numbers, as well as the gap width-to-heated surface diameter ratio; and uses the temperature difference between the heated surface and the ambient fluid in the definition of Rayleigh number. The characteristic length is the gap size and the film temperature is the average fluid temperature.

关键词： function diameter different independent different characteristic horizontal downward

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Numerical simulation of liquid falling film on horizontal circular tubes

Fengdan SUN, Songlin XU, Yongchuan GAO

《化学科学与工程前沿（英文）》 2012年第6卷第3期页码 322-328 doi: 10.1007/s11705-012-1296-z

摘要： The objective of this study is to investigate numerically the flow characteristics of falling film on horizontal circular tubes. Numerical simulations are performed using FLUENT for 2D configurations with one and two cylinders. The volume of fluid method is used to track the motion of liquid falling film and the gas-liquid interface. The effect of flow characteristics on heat and transfer coefficient may be remarkable, although it has been neglected in previous studies. The velocity distribution and the film thickness characteristics on the top tube, some special flow characteristics on the bottom tube, intertube flow modes and effect of liquid feeder height on flow characteristics have been studied. Our simulations indicate that 1) the velocity distributions of the upper and lower parts of the tube are not strictly symmetric and non-uniform, 2) the film thickness depends on flow rate and angular distributions, 3) the flow characteristics of the top tube are different from those of the bottom tube, 4) three principal and two intermediate transition modes are distinguished, and 5) the liquid feed height plays an important role on the formation of falling film. The numerical results are in a good agreement with the theoretical values by the Nusselt model and the reported results.

关键词： falling film horizontal tube flow characteristics film thickness liquid feeder height

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New technique of precision necking for long tubes with variable wall thickness

Yongqiang GUO, Chunguo XU, Jingtao HAN, Zhengyu WANG

《机械工程前沿（英文）》 2020年第15卷第4期页码 622-630 doi: 10.1007/s11465-019-0565-7

摘要： This study analyzed the deformation law of rear axles with variable wall thickness under bidirectional horizontal extrusion and found that necking was accompanied by upsetting deformation through theoretical calculation, numerical simulation, and experimental research. The sequence and occurrence of necking and upsetting deformations were obtained. A theory of deformation was proposed by controlling the distribution of temperature field. Effective processes to control the wall thickness of rear axle at different positions were also proposed. The ultimate limit deformation with a necking coefficient of 0.68 could be achieved using the temperature gradient coefficient. A new technology of two-step heating and two-step extrusion for a 13 t rear axle was developed, qualified test samples were obtained, and suggestions for further industrial application were put forward.

关键词： extrusion rear axle necking coefficient temperature gradient

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Numerical analysis of bearing behaviors of single batter piles under horizontal loads in various directions

《结构与土木工程前沿（英文）》 2023年第17卷第2期页码 224-237 doi: 10.1007/s11709-022-0914-1

摘要： The horizontal bearing behavior of a single batter pile (SBP) is vital to its application in practical engineering; however, the horizontal responses of SBPs change with the directions of horizontal loads, and this phenomenon is rarely investigated. Therefore, the directional differences in the horizontal bearing behaviors of SBPs are investigated in this study. Four model tests are conducted to preliminarily examine the effects of the skew angle of horizontal loads on the horizontal bearing capacities and distributions of the bending moments of the SBPs. Subsequently, the differences in the responses of the SBPs under horizontal loads in various directions at full scale are analyzed comprehensively via finite-element (FE) analysis. The effects of the skew angle on SBP-soil interaction are discussed. Moreover, an empirical design method is proposed based on the FE analysis results to predict the bearing ratios of SBPs in medium-dense and dense sand while considering the effects of the skew angle, batter angle, and pile diameter. The method is confirmed to be effective, as confirmed by the close agreement between the predicting results with the model test (reported in this study) and centrifuge model test results (reported in the literature).

关键词： single batter pile skew horizontal load model test finite-element analysis empirical design method

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Experimental study on shear behavior of reinforced concrete beams with web horizontal reinforcement

Dong XU,Yu ZHAO,Chao LIU

《结构与土木工程前沿（英文）》 2014年第8卷第4期页码 325-336 doi: 10.1007/s11709-014-0080-1

摘要： In determining the shear capacity of reinforced concrete beams, current codes do not provide any calculation method to evaluate the influence of web horizontal reinforcement, although they exist as structural reinforcements (or skin reinforcement). The present paper comprises results of 11 reinforced concrete beams in an effort to investigate the influence of web horizontal reinforcement on the shear behavior of reinforced concrete beams. The primary design variables are the shear-span-depth ratio, different reinforcement ratio of stirrups and web horizontal reinforcement. Influence of web horizontal reinforcement on crack patterns and failure mode was studied. It was found that web horizontal reinforcement can increase the shear capacity of the beams and restrain growth of inclined cracks effectively. Test results are very valuable, as very few references of shear tests can be found focusing on the effect of web horizontal reinforcement on the shear capacity of the beams.

关键词： reinforced concrete beam shear strength web horizontal reinforcement experiments

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钢坯加热的数值模拟

陈冠军

《中国工程科学》 2010年第12卷第2期页码 57-61

摘要：

借助CFD仿真手段，模拟蓄热式加热炉内钢坯加热的实际状况，研究了钢坯长度、宽度方向上下表面和中心温度的温度分布，提出钢坯存在上下温差、四角边缘温度高和靠近出钢口钢坯温度低等问题。同时，研究了炉内不同厚度钢坯与加热时间的基本关系，比较了仿真计算结果与实际炉内加热时间，通过数值拟合，得出钢坯厚度与加热时间的拟合公式，可在生产实际中使用。上述研究结果可为加热炉钢坯加热制度的制定和优化提供依据。

关键词：加热炉钢坯加热模拟

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Optimization model for rotor blades of horizontal axis wind turbines

LIU Xiong, CHEN Yan, YE Zhiquan

《机械工程前沿（英文）》 2007年第2卷第4期页码 483-488 doi: 10.1007/s11465-007-0084-9

摘要： This paper presents an optimization model for rotor blades of horizontal axis wind turbines. The model refers to the wind speed distribution function on the specific wind site, with an objective to satisfy the maximum annual energy output. To speed up the search process and guarantee a global optimal result, the extended compact genetic algorithm (ECGA) is used to carry out the search process. Compared with the simple genetic algorithm, ECGA runs much faster and can get more accurate results with a much smaller population size and fewer function evaluations. Using the developed optimization program, blades of a 1.3 MW stall-regulated wind turbine are designed. Compared with the existing blades, the designed blades have obviously better aerodynamic performance.

关键词： population extended algorithm developed optimization accurate

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Impact of climate change on building heating energy consumption in Tianjin

Cao XIANG, Zhe TIAN

《能源前沿（英文）》 2013年第7卷第4期页码 518-524 doi: 10.1007/s11708-013-0261-y

摘要： This paper investigated the variation of building heating energy consumption caused by global warming in Tianjin, China. Based on the hourly historical and monthly projected future (B1/A1B emissions scenarios) meteorological data, the variation of those relevant meteorological parameters was first analyzed. A TRNSYS simulation model for a reference building was introduced to investigate historical variation of office building energy consumption. The results showed that the 10-year-average heating energy consumption of 2001–2010 had reduced by 16.1% compared to that of 1961–1970. By conducting principal component analysis and regression analysis, future variation of building heating load was studied. For B1/A1B emissions scenarios, the multi-year-average heating load was found to decrease by 9.7% (18.1%)/10.2% (22.7%) compared to that of 1971–2010 by 2011–2050 (2051–2100).

关键词： global warming office building heating energy consumption

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标题作者时间类型操作

A study of spray granulation in vibrated fluidized bed with internal heating tubes

Xiaoheng PAN, Shichao YE, Zeguang ZHANG, Li ZHANG, Xuejun ZHU

期刊论文

Numerical simulation on flow of ice slurry in horizontal straight tube

Shengchun LIU,Ming SONG,Ling HAO,Pengxiao WANG

期刊论文

High-efficiency inspecting method for mobile robots based on task planning for heat transfer tubes in

期刊论文

Theoretical study on the confine-stiffening effect and fractal cracking of square concrete filled steel tubes

期刊论文

Civil and structural engineering applications, recent trends, research and developments on pultruded fiber reinforced polymer closed sections: a review

Alfred Kofi GAND, Tak-Ming CHAN, James Toby MOTTRAM

期刊论文

A state-of-the-art review of solar passive building system for heating or cooling purpose

Arun Kumar NANDA,C K PANIGRAHI

期刊论文

A district heating system based on absorption heat exchange with CHP systems

Lin FU, Yan LI, Yi JIANG, Shigang ZHANG,

期刊论文

Natural convection heat transfer of water in a horizontal circular gap

SU Guanghui, WU Yingwei, Kenichiro Sugiyama

期刊论文

Numerical simulation of liquid falling film on horizontal circular tubes