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Investigation on available wind energy at Tungku beach

M. G. YAZDANI, M. A. SALAM

《能源前沿(英文)》 2012年 第6卷 第3期   页码 275-279 doi: 10.1007/s11708-012-0194-x

摘要: In this paper, wind velocities and directions (sea and land) are recorded in different days and times. The data collected were compared with the weather data from the Brunei Darussalam Meteorological Service (BDMS) and the findings of other researchers and were found to be in good agreement. The potential of wind energy is predicted from the available data collected. The average generated power (forenoon and afternoon) is found to be 25 (mean) and 18 W (median), 101 (mean) and 73 W (median), 912 (mean) and 660 W (median), 10137 (mean) and 7331 W (median) for a rotor with a diameter of 2.5, 5, 15 and 50 m, respectively. The power density for wind farming is found to be 0.26 (mean) and 0.19 (median), 0.31 (mean) and 0.22 (median) for the rotor whose diameter is 2.5 and 50 m, respectively, while the average values are found to be 0.28 (mean) and 0.2 (median) for the rotor whose diameter is 5 and 15 m.

关键词: wind velocity     temperature     tower height     power density     Raleigh distribution     electrical power    

Yield-height correlation and QTL localization for plant height in two lowland switchgrass populations

Shiva O. MAKAJU, Yanqi WU, Michael P. ANDERSON, Vijaya G. KAKANI, Michael W. SMITH, Linglong LIU, Hongxu DONG, Dan CHANG

《农业科学与工程前沿(英文)》 2018年 第5卷 第1期   页码 118-128 doi: 10.15302/J-FASE-2018201

摘要: Switchgrass ( L.), as a model herbaceous crop species for bioenergy production, is targeted to improve biomass yield and feedstock quality. Plant height is a major component contributing to biomass yield. Accordingly, the objectives of this research were to analyze phenotypic variation for biomass and plant height and the association between them and to localize associated plant height QTLs. Two lowland switchgrass mapping populations, one selfed and another hybrid population established in the field at Perkins and Stillwater, Oklahoma, were deployed in the experiment for two years post establishment. Large genetic variation existed for plant biomass and height within the two populations. Plant height was positively correlated with biomass yield in the selfed population ( = 0.39, <0.0001) and the hybrid population ( = 0.41, <0.0001). In the selfed population, a joint analysis across all environments revealed 10 QTLs and separate analysis for each environment, collectively revealed 39 QTLs related to plant height. In the hybrid population, the joint analysis across overall environments revealed 35 QTLs and the separate analysis for each environment revealed 38 QTLs. The findings of this research contribute new information about the genetic control for plant height and will be useful for future plant breeding and genetic improvement programs in lowland switchgrass.

关键词: yield-height     QTL localization     lowland switchgrass    

Influence of nozzle height to width ratio on ignition and NO

Liutao SUN, Yonghong YAN, Rui SUN, Zhengkang PENG, Chunli XING, Jiangquan WU

《能源前沿(英文)》 2021年 第15卷 第2期   页码 431-448 doi: 10.1007/s11708-021-0726-3

摘要: To improve the ignition behavior and to reduce the high NO emissions of blended pulverized fuels (PF) of semicoke (SC), large-scale experiments were conducted in a 300 kW fired furnace at various nozzle settings, i.e., ratios (denoted by / ) of the height of the rectangular burner nozzle to its width of 1.65, 2.32, and 3.22. The combustion tests indicate that the flame stability, ignition performance, and fuel burnout ratio were significantly improved at a nozzle setting of / = 2.32. The smaller / delayed ignition and caused the flame to concentrate excessively on the axis of the furnace, while the larger / easily caused the deflection of the pulverized coal flame, and a high-temperature flame zone emerged close to the furnace wall. NO emissions at the outlet of the primary zone decreased from 447 to 354 mg/m (O = 6%), and the ignition distance decreased from 420 to 246 mm when the / varied from 1.65 to 3.22. Furthermore, the ratio (denoted by / ) of the strong reduction zone area to the combustion reaction zone area was defined experimentally by the CO concentration to evaluate the reduction zone. The / rose monotonously, but its restraining effects on NO formation decreased as / increased. The results suggested that in a test furnace, regulating the nozzle / conditions sharply reduces NO emissions and improves the combustion efficiency of SC blends possessing an appropriate jet rigidity.

关键词: rectangular jet burner     nozzle height to width ratio     ignition characteristics     pyrolyzed semicoke (SC) and bituminous blend     NOx formation    

Safety and serviceability assessment for high-rise tower crane to turbulent winds

Zhi SUN, Nin HOU, Haifan XIANG

《结构与土木工程前沿(英文)》 2009年 第3卷 第1期   页码 18-24 doi: 10.1007/s11709-009-0009-2

摘要: Tower cranes are commonly used facilities for the construction of high-rise structures. To ensure their workability, it is very important to analyze their response and evaluate their condition under extreme conditions. This paper proposes a general scheme for safety and serviceability assessment of high-rise tower crane to turbulent winds based on time domain buffeting response analysis. Spatially correlated wind velocity field at the location of the tower crane was first simulated using an algorithm for generating the time domain samples of a stationary, multivariate stochastic process according to some prescribed spectral density matrix. The buffeting forces applied to the structure were computed according to the above-simulated wind velocity fluctuations and the lift, drag, and moment coefficients obtained from a CFD computation. Those spatially correlated loads were then fed into a well calibrated finite element model and the nonlinear time history analysis was conducted to compute structural buffeting response. Compared with structural on-site response measurement, the computed response using the proposed method has good precision. The proposed method is then adopted for analyzing the buffeting response of an in-use tower crane under the design wind speed and the maximum operational wind speed for safety and serviceability assessment.

关键词: tower crane     buffeting response     wind velocity     modeling    

Practice and Experience of Canton Tower Project Management

Rong-hua Yi

《工程管理前沿(英文)》 2016年 第3卷 第1期   页码 74-79 doi: 10.15302/J-FEM-2016013

摘要: This paper presents a brief introduction about the preliminary consulting and tender agent of Canton Tower, the basic situation of the whole-process supervision on the construction site, and a general summary of the Canton Tower project management. What’s more, the author suggests that some guidelines be formed for supervision enterprises involved in large-scale project management.

关键词: Canton Tower     consultation     tender agent     whole-process     supervision    

Power fluctuation and power loss of wind turbines due to wind shear and tower shadow

Binrong WEN, Sha WEI, Kexiang WEI, Wenxian YANG, Zhike PENG, Fulei CHU

《机械工程前沿(英文)》 2017年 第12卷 第3期   页码 321-332 doi: 10.1007/s11465-017-0434-1

摘要:

The magnitude and stability of power output are two key indices of wind turbines. This study investigates the effects of wind shear and tower shadow on power output in terms of power fluctuation and power loss to estimate the capacity and quality of the power generated by a wind turbine. First, wind speed models, particularly the wind shear model and the tower shadow model, are described in detail. The widely accepted tower shadow model is modified in view of the cone-shaped towers of modern large-scale wind turbines. Power fluctuation and power loss due to wind shear and tower shadow are analyzed by performing theoretical calculations and case analysis within the framework of a modified version of blade element momentum theory. Results indicate that power fluctuation is mainly caused by tower shadow, whereas power loss is primarily induced by wind shear. Under steady wind conditions, power loss can be divided into wind farm loss and rotor loss. Wind farm loss is constant at 3α(3α−1)R2/(8H2). By contrast, rotor loss is strongly influenced by the wind turbine control strategies and wind speed. That is, when the wind speed is measured in a region where a variable-speed controller works, the rotor loss stabilizes around zero, but when the wind speed is measured in a region where the blade pitch controller works, the rotor loss increases as the wind speed intensifies. The results of this study can serve as a reference for accurate power estimation and strategy development to mitigate the fluctuations in aerodynamic loads and power output due to wind shear and tower shadow.

关键词: wind turbine     wind shear     tower shadow     power fluctuation     power loss    

Impacts of solar multiple on the performance of direct steam generation solar power tower plant with

Yan LUO, Xiaoze DU, Lijun YANG, Chao XU, Muhammad AMJAD

《能源前沿(英文)》 2017年 第11卷 第4期   页码 461-471 doi: 10.1007/s11708-017-0503-5

摘要: Solar multiple (SM) and thermal storage capacity are two key design parameters for revealing the performance of direct steam generation (DSG) solar power tower plant. In the case of settled land area, SM and thermal storage capacity can be optimized to obtain the minimum levelized cost of electricity (LCOE) by adjusting the power generation output. Taking the dual-receiver DSG solar power tower plant with a given size of solar field equivalent electricity of 100 MW in Sevilla as a reference case, the minimum LCOE is 21.77 ¢/kWh with an SM of 1.7 and a thermal storage capacity of 3 h. Besides Sevilla, two other sites are also introduced to discuss the influence of annual DNI. When compared with the case of Sevilla, the minimum LCOE and optimal SM of the San Jose site change just slightly, while the minimum LCOE of the Bishop site decreases by 32.8% and the optimal SM is reduced to 1.3. The influence of the size of solar field equivalent electricity is studied as well. The minimum LCOE decreases with the size of solar field, while the optimal SM and thermal storage capacity still remain unchanged. In addition, the sensitivity of different investment in sub-system is investigated. In terms of optimal SM and thermal storage capacity, they can decrease with the cost of thermal storage system but increase with the cost of power generation unit.

关键词: direct steam generation     solar power tower     solar multiple     thermal energy storage capacity     levelized cost of electricity (LCOE)    

泰州大桥——世界首座千米级三塔悬索桥

钟建驰

《中国工程科学》 2010年 第12卷 第4期   页码 4-8

摘要:

2007年12月开工建设的泰州大桥位于江苏省中部,连接泰州与镇江,为世界首座千米级三塔连跨悬索桥,同时中塔采用世界首个纵向人字型钢塔,中塔基础采用世界上入土最深的水中沉井基础。为了建造这项宏伟的工程,针对众多技术挑战,建设者采取了一系列的创新技术:三塔悬索桥的设计技术,江中大型深井的定位着床、封底技术,人字型钢中塔的钢混结合连接技术、超厚钢板的焊接加工技术以及钢中塔异型节段的精确加工与控制技术等。

关键词: 三塔悬索桥     创新     设计     水中沉井     人字型钢塔    

Choosing configurations of transmission line tower grounding by back flashover probability value

Dmitry KUKLIN

《能源前沿(英文)》 2016年 第10卷 第2期   页码 213-226 doi: 10.1007/s11708-016-0398-6

摘要: There is a considerable number of works devoted to electrical characteristics of grounding. These characteristics are important in general. However, in application to grounding of transmission line towers they are not enough to determine what grounding construction is preferable in some particular case, because these characteristics are calculated or measured apart from the grounded object, and only limited number of current (or voltage) source waveforms is used. This paper indicates reasons in favor of the fact that to choose the optimum design of grounding, the calculation model should include the tower as it is. The probability of back flashover, which provides both qualitative and quantitative estimate of the grounding structure efficiency, can be taken as the criterion for the grounding design. The insulation flashover probability is calculated on the basis of engineering method, which evaluates breakdown strength of insulation for nonstandard waveshapes, and probability data on lightning currents. Different approaches are examined for identifying the back flashover probability, as not only amplitudes but also other parameters can be taken into account. Finite-difference time-domain method is used for calculations of transients. It is found that lightning current waveform can greatly influence calculated back flashover probability value.

关键词: grounding     transmission line tower     back flashover probability     FDTD method    

螺旋结构冷却塔的塔板设计方法

黄锐

《中国工程科学》 2008年 第10卷 第11期   页码 43-46

摘要:

针对冷却塔中螺旋结构类型的气液交换塔,提出其内部螺旋塔板形状的设计方法,包括塔壁上外螺旋线和塔中心轴管上内螺旋线的位置确定,以及两线之间螺旋曲面板在平面上的拓扑尺寸。通过塔的几何参数确定螺旋曲面板设计的关键参数,可实现扭曲状塔板与塔壁及内轴的准确配合。

关键词: 冷却塔     塔板设计     螺旋曲面     拓扑    

泰州大桥中间塔鞍座抗滑安全评估

阮欣,阮静,陈艾荣,郭济

《中国工程科学》 2012年 第14卷 第5期   页码 71-74

摘要:

在分析鞍座抗滑机理的基础上,建立了基于最大静摩擦系数的三塔悬索桥中间塔鞍座抗滑基本评估模型,并发展了多种鞍座抗滑评估方法。包括基于目前使用的设计规范评估鞍座抗滑安全的确定性方法;基于静态车辆数据合成随机车流,并利用Rice公式外推其荷载效应极值,进而研究鞍座抗滑安全性能的评估方法;以及基于车辆荷载效应和抗力概率模型的鞍座抗滑概率评估方法。用上述三种方法分别对泰州大桥鞍座抗滑安全性进行全面评估,表明泰州大桥中塔鞍座抗滑安全可靠。

关键词: 三塔两跨悬索桥     中间塔鞍座     确定性评估     概率评估    

设计创新对东方明珠和雅加达塔的贡献

江欢成

《中国工程科学》 1999年 第1卷 第1期   页码 30-35

摘要:

东方明珠,塔高463.85m,高居亚洲之二,世界第三,被公认为是上海最重要的城市标志。雅加达塔,高558m,建筑面积32万m2,均堪称世界之最。东方明珠的成功,雅加达塔的中标,在很大程度上要归功于设计创新。东方明珠设计者用一串明珠来标志上海,用带斜撑的巨型空间框架作为主体结构,打破了混凝土电视塔常用的单筒体结构模式,从而获得了很好的标志性。这种结构同时很有利于抗风抗震。该塔还采用了许多高新技术,如预应力混凝土壳、双重悬挂钢结构和攀升天线等设计,它们巧妙而合理地解决了复杂的结构构造和高难度施工的问题。设计者在雅加达塔上,继承和发扬东方明珠的长处,克服它的不足,并赋予许多新的创造。为了使新的创造建立在坚实科学基础上,设计者为东方明珠塔进行了大量的试验研究工作。

关键词: 创新     电视塔     空间框架     斜撑     球体     钢桅杆     悬挂结构    

Optimization design of anti-seismic engineering measures for intake tower based on non-dominated sorting

《结构与土木工程前沿(英文)》   页码 1428-1441 doi: 10.1007/s11709-023-0998-2

摘要: High-rise intake towers in high-intensity seismic areas are prone to structural safety problems under vibration. Therefore, effective and low-cost anti-seismic engineering measures must be designed for protection. An intake tower in northwest China was considered the research object, and its natural vibration characteristics and dynamic response were first analyzed using the mode decomposition response spectrum method based on a three-dimensional finite element model. The non-dominated sorting genetic algorithm-II (NSGA-II) was adopted to optimize the anti-seismic scheme combination by comprehensively considering the dynamic tower response and variable project cost. Finally, the rationality of the original intake tower antiseismic design scheme was evaluated according to the obtained optimal solution set, and recommendations for improvement were proposed. The method adopted in this study may provide significant references for designing anti-seismic measures for high-rise structures such as intake towers located in high-intensity earthquake areas.

关键词: intake tower     NSGA-II     mode decomposition response spectrum method     anti-seismic engineering measures     optimization design     variable project cost    

Numerical analysis of nonlinear dynamic behavior of earth dams

Babak EBRAHIMIAN

《结构与土木工程前沿(英文)》 2011年 第5卷 第1期   页码 24-40 doi: 10.1007/s11709-010-0082-6

摘要: A numerical study is conducted to investigate the dynamic behavior of earth dams. The numerical investigation employs a fully nonlinear dynamic finite difference analysis incorporating a simple elastic perfectly plastic constitutive model to describe the stress-strain response of the soil and the Rayleigh damping to increase the level of hysteretic damping. The extended Masing rules are implemented into the constitutive model to explain more accurately the soil response under general cyclic loading. The soil stiffness and hysteretic damping change with loading history. The procedures for calibrating the constructed numerical model with centrifuge test data and also a real case history are explained. For the latter, the Long Valley (LV) earth dam subjected to the 1980 Mammoth Lake earthquake as a real case-history is analyzed and the obtained numerical results are compared with the real measurements at the site in both the time and frequency domains. Relatively good agreement is observed between computed and measured quantities. It seems that the Masing rules combined with a simple elasto-plastic model gives reasonable numerical predictions. Afterwards, a comprehensive parametric study is carried out to identify the effects of dam height, input motion characteristics, soil behavior, strength of the shell materials and dam reservoir condition on the dynamic response of earth dams. Three real earthquake records with different levels and peak acceleration values (PGAs) are used as input motions. The results show that the crest acceleration decreases when the dam height increases and no amplification is observed. Further, more inelastic behavior and more earthquake energy absorption are observed in higher dams.

关键词: earth dam     numerical     nonlinear response     dynamic analysis     earthquake     dam height    

Analyzing the nonlinear vibrational wave differential equation for the simplified model of Tower Cranes

M.R. AKBARI,D.D. GANJI,A.R. AHMADI,Sayyid H. Hashemi KACHAPI

《机械工程前沿(英文)》 2014年 第9卷 第1期   页码 58-70 doi: 10.1007/s11465-014-0289-7

摘要:

In the current paper, a simplified model of Tower Cranes has been presented in order to investigate and analyze the nonlinear differential equation governing on the presented system in three different cases by Algebraic Method (AGM). Comparisons have been made between AGM and Numerical Solution, and these results have been indicated that this approach is very efficient and easy so it can be applied for other nonlinear equations. It is citable that there are some valuable advantages in this way of solving differential equations and also the answer of various sets of complicated differential equations can be achieved in this manner which in the other methods, so far, they have not had acceptable solutions. The simplification of the solution procedure in Algebraic Method and its application for solving a wide variety of differential equations not only in Vibrations but also in different fields of study such as fluid mechanics, chemical engineering, etc. make AGM be a powerful and useful role model for researchers in order to solve complicated nonlinear differential equations.

关键词: Algebraic Method (AGM)     tower crane     oscillating system     angular frequency    

标题 作者 时间 类型 操作

Investigation on available wind energy at Tungku beach

M. G. YAZDANI, M. A. SALAM

期刊论文

Yield-height correlation and QTL localization for plant height in two lowland switchgrass populations

Shiva O. MAKAJU, Yanqi WU, Michael P. ANDERSON, Vijaya G. KAKANI, Michael W. SMITH, Linglong LIU, Hongxu DONG, Dan CHANG

期刊论文

Influence of nozzle height to width ratio on ignition and NO

Liutao SUN, Yonghong YAN, Rui SUN, Zhengkang PENG, Chunli XING, Jiangquan WU

期刊论文

Safety and serviceability assessment for high-rise tower crane to turbulent winds

Zhi SUN, Nin HOU, Haifan XIANG

期刊论文

Practice and Experience of Canton Tower Project Management

Rong-hua Yi

期刊论文

Power fluctuation and power loss of wind turbines due to wind shear and tower shadow

Binrong WEN, Sha WEI, Kexiang WEI, Wenxian YANG, Zhike PENG, Fulei CHU

期刊论文

Impacts of solar multiple on the performance of direct steam generation solar power tower plant with

Yan LUO, Xiaoze DU, Lijun YANG, Chao XU, Muhammad AMJAD

期刊论文

泰州大桥——世界首座千米级三塔悬索桥

钟建驰

期刊论文

Choosing configurations of transmission line tower grounding by back flashover probability value

Dmitry KUKLIN

期刊论文

螺旋结构冷却塔的塔板设计方法

黄锐

期刊论文

泰州大桥中间塔鞍座抗滑安全评估

阮欣,阮静,陈艾荣,郭济

期刊论文

设计创新对东方明珠和雅加达塔的贡献

江欢成

期刊论文

Optimization design of anti-seismic engineering measures for intake tower based on non-dominated sorting

期刊论文

Numerical analysis of nonlinear dynamic behavior of earth dams

Babak EBRAHIMIAN

期刊论文

Analyzing the nonlinear vibrational wave differential equation for the simplified model of Tower Cranes

M.R. AKBARI,D.D. GANJI,A.R. AHMADI,Sayyid H. Hashemi KACHAPI

期刊论文