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Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough

Honglun YANG, Qiliang WANG, Jingyu CAO, Gang PEI, Jing LI

《能源前沿(英文)》 2020年 第14卷 第4期   页码 867-881 doi: 10.1007/s11708-020-0707-y

摘要: This paper proposes a comprehensive thermodynamic and economic model to predict and compare the performance of concentrated solar power plants with traditional and novel receivers with different configurations involving operating temperatures and locations. The simulation results reveal that power plants with novel receivers exhibit a superior thermodynamic and economic performance compared with traditional receivers. The annual electricity productions of power plants with novel receivers in Phoenix, Sevilla, and Tuotuohe are 8.5%, 10.5%, and 14.4% higher than those with traditional receivers at the outlet temperature of 550°C. The levelized cost of electricity of power plants with double-selective-coated receivers can be decreased by 6.9%, 8.5%, and 11.6%. In Phoenix, the optimal operating temperature of the power plants is improved from 500°C to 560°C by employing a novel receiver. Furthermore, the sensitivity analysis of the receiver heat loss, solar absorption, and freeze protection temperature is also conducted to analyze the general rule of influence of the receiver performance on power plants performance. Solar absorption has a positive contribution to annual electricity productions, whereas heat loss and freeze protection temperature have a negative effect on electricity outputs. The results indicate that the novel receiver coupled with low melting temperature molten salt is the best configuration for improving the overall performance of the power plants.

关键词: concentrated solar power     parabolic trough receiver     heat loss     solar energy     annual performance    

Corrigendum to “Multidecadal Trends in Large-Scale Annual Mean SATa Based on CMIP5 Historical Simulations Corrigendum

Nan Xing,Jianping Li,Lanning Wang

《工程(英文)》 2017年 第3卷 第3期   页码 428-428 doi: 10.1016/J.ENG.2017.03.015

Proposal of a probabilistic assessment of structural collapse concomitantly subject to earthquake and gas explosion

Gholamreza ABDOLLAHZADEH, Hadi FAGHIHMALEKI

《结构与土木工程前沿(英文)》 2018年 第12卷 第3期   页码 425-437 doi: 10.1007/s11709-017-0427-5

摘要:

In recent decades, many public buildings, located in seismic-prone residential areas, had to grapple with abnormal loads against which the structures were unguarded. In this piece of research, an ordinary three dimensional reinforced concrete building is selected as case study. The building is located in an earthquake-prone region; however, it is designed according to seismic building codes. Yet, it is not shielded against abnormal loads, such as blasts. It is assumed that the building suffers a blast load, due to mechanical/thermal installation failure during or after intense seismic oscillations. These two critical incidents are regarded codependent and compatible. So the researchers developed scenarios and tried to assess different probabilities for each scenario and carried out an analysis to ensure if progressive collapse had set in or not. In the first step, two analysis models were used for each scenario; a non-linear dynamic time history analysis and a blast local dynamic analysis. In the second step, having the structural destructions of the first step in view, a pushdown analysis was carried out to determine the severity of progressive collapse and assess building robustness. Finally, the annual probability of structural collapse under simultaneous earthquake and blast loads was estimated and offered.

关键词: gas blast     pushdown analysis     progressive collapse     annual probability of structural collapse     3D model of structure    

兴建年产一千吨电子级多晶硅工厂的思考

梁骏吾

《中国工程科学》 2000年 第2卷 第6期   页码 33-35

摘要:

文章简要评述了世界以及中国的电子级多晶硅的生产能力和市场需求。在2000年和2010年中国对多晶硅的需求分别是736 t/a和1304 t/a。但近几年中国的多晶硅生产仅达到80 t/a,所以在中国建设一座年产1000 t电子级多晶硅的工厂是很合理的。然而由最新统计数据可知,自1997年以来,世界多晶硅生产能力连年均超过市场需求,而且在最近的将来,这一趋势将会继续。为了占领国内多晶硅市场,未来的多晶硅工厂将面临挑战,产品质量和生产成本是应当考虑的最重要指标。为了占领国内市场,在保证多晶硅产品纯度的前提下,生产成本只能略微超过20美元/kg。

关键词: 多晶硅     半导体工业     规模生产    

Determination of a suitable index for a solvent via two-column extractive distillation using a heuristic method

Zhaoyou Zhu, Guoxuan Li, Yao Dai, Peizhe Cui, Dongmei Xu, Yinglong Wang

《化学科学与工程前沿(英文)》 2020年 第14卷 第5期   页码 824-833 doi: 10.1007/s11705-019-1867-3

摘要: The traditional approach to solvent selection in the extractive distillation process strictly focuses on the change in the relative volatility of light-heavy components induced by the solvent. However, the total annual cost of the process may not be minimal when the solvent induces the largest change in relative volatility. This work presents a heuristic method for selecting the optimal solvent to minimize the total annual cost. The functional relationship between the relative volatility and the total annual cost is established, where the main factors, such as the relative volatility of the light-heavy components and the relative volatility of the heavy-component solvent, are taken into account. Binary azeotropic mixtures of methanol-toluene and methanol-acetone are separated to verify the feasibility of the model. The results show that using the solvent with the minimal two-column extractive distillation index, the process achieves a minimal total annual cost. The method is conducive for sustainable advancements in chemistry and engineering because a suitable solvent can be selected without simulation verification.

关键词: heuristic method     solvent selection     extractive distillation     total annual cost    

Probabilistic safety assessment of self-centering steel braced frame

Navid RAHGOZAR, Nima RAHGOZAR, Abdolreza S. MOGHADAM

《结构与土木工程前沿(英文)》 2018年 第12卷 第1期   页码 163-182 doi: 10.1007/s11709-017-0384-z

摘要: The main drawback of conventional braced frames is implicitly accepting structural damage under the design earthquake load, which leads to considerable economic losses. Controlled rocking self-centering system as a modern low-damage system is capable of minimizing the drawbacks of conventional braced frames. This paper quantifies main limit states and investigates the seismic performance of self-centering braced frame using a Probabilistic Safety Assessment procedure. Margin of safety, confidence level, and mean annual frequency of the self-centering archetypes for their main limit states, including PT yield, fuse fracture, and global collapse, are established and are compared with their acceptance criteria. Considering incorporating aleatory and epistemic uncertainties, the efficiency of the system is examined. Results of the investigation indicate that the design of low- and mid-rise self-centering archetypes could provide the adequate margin of safety against exceeding the undesirable limit-states.

关键词: self-centering steel braced frame     mean annual frequency     safety assessment     confidence level     margin of safety    

Determining the optimum economic insulation thickness of double pipes buried in the soil for district heating systems

Fating LI, Pengfei JIE, Zhou FANG, Zhimei WEN

《能源前沿(英文)》 2021年 第15卷 第1期   页码 170-185 doi: 10.1007/s11708-020-0680-5

摘要: The insulation thickness (IT) of double pipes buried in the soil (DPBIS) for district heating (DH) systems was optimized to minimize the annual total cost of DPBIS for DH systems. An optimization model to obtain the optimum insulation thickness (OIT) and minimum annual total cost (MATC) of DPBIS for DH systems was established. The zero point theorem and fsolve function were used to solve the optimization model. Three types of heat sources, four operating strategies, three kinds of insulation materials, three buried depth (BD) values, and seven nominal pipe size (NPS) values were considered in the calculation of the OIT and MATC of DPBIS for DH systems, respectively. The optimization results for the above factors were compared. The results show that the OIT and MATC of DPBIS for DH systems can be obtained by using the optimization model. Sensitivity analysis was conducted to investigate the impact of some economic parameters, i.e., unit heating cost, insulation material price, interest rate, and insulation material lifetime, on optimization results. It is found out that the impact of sensitivity factors on the OIT and MATC of DPBIS for DH systems is different.

关键词: double pipes     optimization model     optimum insulation thickness     minimum annual total cost    

Functional trait differences between native bunchgrasses and the invasive grass

Huiqin HE, Thomas A. MONACO, Thomas A. JONES

《农业科学与工程前沿(英文)》 2018年 第5卷 第1期   页码 139-147 doi: 10.15302/J-FASE-2017175

摘要: We conducted 30- and 60-d greenhouse experiments to compare functional traits of (invasive annual grass) and four perennial bunchgrasses under well-watered or drought conditions. Even under drought, experienced significantly less stress (i.e., higher xylem pressure potential and greater shoot water content, water use per day and water-use efficiency) and biomass production than the perennial grasses after 30 d. However, after 60 d, its superiority was reduced under infrequent watering. Differences among perennial grasses were more pronounced for physiological traits under infrequent watering and for morphological traits under frequent watering. (fast-growing species) had a higher transpiration rate, lower leaf temperature, and lower water-use efficiency than the other grasses after 30 d. In contrast, (slow-growing) had lower xylem pressure potential and higher leaf temperature than all other grasses under infrequent watering. Under frequent watering, shoot dry mass and specific leaf area of was matched by (moderate-growing species). Our results indicate that multiple-species plantings or seedings are necessary to foster greater weed resistance against . We also emphasize that when choosing plant material for restoration, performance during both pulse (resource-rich) and inter-pulse (resource-poor) periods should be considered.

关键词: annual grass     comparative growth     drought response     invasive plant     native grass     specific leaf area     soil-water use    

Potential sources of unintentionally produced PCB, HCB, and PeCBz in China: A preliminary overview

Xiaotu Liu, Heidelore Fiedler, Wenwen Gong, Bin Wang, Gang Yu

《环境科学与工程前沿(英文)》 2018年 第12卷 第6期 doi: 10.1007/s11783-018-1036-9

摘要:

A preliminary analysis of potential sources for unintentionally produced PCB, HCB and PeCBz in China.

Activity rates of sources for reference years from 2000 to 2015 provided.

Emissions from a number of sources summarized and compared.

Implications for future research and regulation discussed.

关键词: Unintentionally produced POPs     Polychlorinated biphenyls     Hexachlorobenzene     Pentachlorobenzene     sources of releases     Annual production activities    

Performance-based and performance-driven architectural design and optimization

Xing SHI

《结构与土木工程前沿(英文)》 2010年 第4卷 第4期   页码 512-518 doi: 10.1007/s11709-010-0090-6

摘要: As the architecture, engineering, and construction (AEC) industry is marching into the sustainable and low-carbon era, the performance of architecture has drawn more attention than ever. Simulation technology has made quantified analysis of architectural performance possible and, therefore, directly enables architects and engineers to incorporate performance analysis into the design work flow. It is argued that performance-based and performance-driven architectural designs differ in that the latter involves computer-aided optimization technique so that the performance can be used as the criteria to truly “drive” the design. The paper starts with a brief introduction of performance issues in architectural design, followed by a review of the evolution of performance-based architectural design. The concept of performance-driven architectural design is presented, and some design projects and research work are reviewed. The driving engine, i.e., optimization technique, and its application in architectural design is discussed. Challenges to making performance-driven design a common practice are explained, and a schematic of integrated performance-based/driven architectural design software is proposed.

关键词: performance     optimization     architectural design     simulation     sustainability    

钢产量增长机制的解析及2000—2007年我国钢产量增长过快原因的探索

陆钟武,岳强

《中国工程科学》 2010年 第12卷 第6期   页码 4-11

摘要:

分两步解析钢产量的增长机制,首先在若干假设条件下提出了钢产量增长的基准模式,其主要特点是钢产量与GDP同步增长,分析了基准模式下的钢产量、在役钢量、GDP以及它们的年增长率;然后讨论偏离基准模式的各种可能性,及其对钢产量增速的影响。在此基础上得到了钢产量年增长率的基本计算式。分析了偏离基准模式对单位GDP钢产量的影响。在对钢产量增长机制进行解析的基础上,广泛联系全社会发生的各种现象,提出使我国钢产量增速远远超过GDP增速的16种现象,提出在宏观调控工作中,要区别对待这些现象。从中、日、美三国单位GDP钢产量数据对比可见,我国降低单位GDP钢产量的空间很大。文章为我国钢铁行业的宏观调控提供了新思路。

关键词: 钢产量     在役钢量     GDP     年增长率     机制     基准模式    

思维的两重性及其向创造性思维的转化 纪念钱学森院士《关于思维科学》发表15周年

梁桂明

《中国工程科学》 2003年 第5卷 第2期   页码 26-34

摘要:

进入21世纪的新时代,带来与思维相关的两个特征:创新与共融。关于创新,如何激发创造性思维?成为热门的话题。从唯物辩证法的哲学的认识论和真理的相对性的高度来探索,发现任何一种思维形式(包括演绎法思维和定势-习惯思维)都具有两重性,即非创造性与创造性并存,在一定条件下,非创造性思维可以转化或激发为创造性思维,产生新知识,获得创新成果。关于共融,如何进行思维的界定和分类,有许多种说法。笔者把心理学与生理学的成果融合起来,形成两大类,即左半脑主导的理性思维和右半脑主导的悟性思维。其基本的思维形式的分类与思维的大类结合,成为两大类7种。把辩证法和共融结合,得到下列结论:理性思维与感性思维的统一,原有知识与新知识的统一,设想与验证的统一,发现与发明的统一,科学(真感)与艺术(美感)的统一。对最后一个结论,笔者以工业产品造型设计原理的探索为例加以说明。此原理在工业设计上属首次推出。

关键词: 创造性思维     转化条件     知识的相对性     融合    

Flexural and longitudinal shear performance of precast lightweight steel–ultra-high performance concrete

《结构与土木工程前沿(英文)》 2023年 第17卷 第5期   页码 704-721 doi: 10.1007/s11709-023-0941-6

摘要: In this study, the flexural and longitudinal shear performances of two types of precast lightweight steel–ultra-high performance concrete (UHPC) composite beams are investigated, where a cluster UHPC slab (CUS) and a normal UHPC slab (NUS) are connected to a steel beam using headed studs through discontinuous shear pockets and full-length shear pockets, respectively. Results show that the longitudinal shear force of the CUS is greater than that of the NUS, whereas the interfacial slip of the former is smaller. Owing to its better integrity, the CUS exhibits greater flexural stiffness and a higher ultimate bearing capacity than the NUS. To further optimize the design parameters of the CUS, a parametric study is conducted to investigate their effects on the flexural and longitudinal shear performances. The square shear pocket is shown to be more applicable for the CUS, as the optimal spacing between two shear pockets is 650 mm. Moreover, a design method for transverse reinforcement is proposed; the transverse reinforcement is used to withstand the splitting force caused by studs in the shear pocket and prevent the UHPC slab from cracking. According to calculation results, the transverse reinforcement can be canceled when the compressive strength of UHPC is 150 MPa and the volume fraction of steel fiber exceeds 2.0%.

关键词: precast steel–UHPC composite beam     flexural performance     longitudinal shear performance     parametric study     transverse reinforcement ratio    

Experimental research on cyclone performance at high temperature

LI Wenqi, CHEN Jianyi

《机械工程前沿(英文)》 2007年 第2卷 第3期   页码 310-317 doi: 10.1007/s11465-007-0055-1

摘要: To predict the influence of operating temperatures on cyclone performance, an experimental investigation was conducted on particle separation in a reverse flow, tangential volute-inlet cyclone separator with a diameter of 300 mm and with air heated up to 973 K. The test powder silica has a mass median diameter of 10 um, while inlet velocity range was 12-36 m/s. Both the separation efficiency and pressure drop of the cyclone were measured as a function of the inlet velocity and operating temperature. At the same inlet velocity, both the separation efficiency and pressure drop decrease with increasing temperature. In addition, optimum inlet velocity, at which the cyclone has its highest separation efficiency, tends to increase with a rise in temperature. An analysis on our own data and published results has shown that the fractional efficiency of a cyclone is a definite function of dimensionless numbers such as the Stokes number, the Reynolds number, the Froude number, dimensionless cyclone inlet area, and dimensionless outlet diameter. A nondimensional experimental correlation of the cyclone performance, including the influence of temperature, was obtained on the basis of our own previous work. The prediction of the influence of temperature on separation efficiencies and pressure drops is in fairly good agreement with experimental results.

关键词: diameter     definite function     nondimensional experimental     cyclone performance     influence    

Comparison of indices for stiffness performance evaluation

Giuseppe CARBONE, Marco CECCARELLI,

《机械工程前沿(英文)》 2010年 第5卷 第3期   页码 270-278 doi: 10.1007/s11465-010-0023-z

摘要: This paper addresses the problem of a numerical evaluation of the stiffness performance for multibody robotic systems. An overview is presented with basic formulation concerning indices that are proposed in literature. New indices are also outlined. Stiffness indices are computed and compared for a case study. Results are used for comparing the effectiveness of the stiffness indices. The main goal is to propose a performance index describing synthetically the elastostatic response of a multibody robotic system and also for design purposes.

关键词: robotics     stiffness     performance indices    

标题 作者 时间 类型 操作

Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough

Honglun YANG, Qiliang WANG, Jingyu CAO, Gang PEI, Jing LI

期刊论文

Corrigendum to “Multidecadal Trends in Large-Scale Annual Mean SATa Based on CMIP5 Historical Simulations

Nan Xing,Jianping Li,Lanning Wang

期刊论文

Proposal of a probabilistic assessment of structural collapse concomitantly subject to earthquake and gas explosion

Gholamreza ABDOLLAHZADEH, Hadi FAGHIHMALEKI

期刊论文

兴建年产一千吨电子级多晶硅工厂的思考

梁骏吾

期刊论文

Determination of a suitable index for a solvent via two-column extractive distillation using a heuristic method

Zhaoyou Zhu, Guoxuan Li, Yao Dai, Peizhe Cui, Dongmei Xu, Yinglong Wang

期刊论文

Probabilistic safety assessment of self-centering steel braced frame

Navid RAHGOZAR, Nima RAHGOZAR, Abdolreza S. MOGHADAM

期刊论文

Determining the optimum economic insulation thickness of double pipes buried in the soil for district heating systems

Fating LI, Pengfei JIE, Zhou FANG, Zhimei WEN

期刊论文

Functional trait differences between native bunchgrasses and the invasive grass

Huiqin HE, Thomas A. MONACO, Thomas A. JONES

期刊论文

Potential sources of unintentionally produced PCB, HCB, and PeCBz in China: A preliminary overview

Xiaotu Liu, Heidelore Fiedler, Wenwen Gong, Bin Wang, Gang Yu

期刊论文

Performance-based and performance-driven architectural design and optimization

Xing SHI

期刊论文

钢产量增长机制的解析及2000—2007年我国钢产量增长过快原因的探索

陆钟武,岳强

期刊论文

思维的两重性及其向创造性思维的转化 纪念钱学森院士《关于思维科学》发表15周年

梁桂明

期刊论文

Flexural and longitudinal shear performance of precast lightweight steel–ultra-high performance concrete

期刊论文

Experimental research on cyclone performance at high temperature

LI Wenqi, CHEN Jianyi

期刊论文

Comparison of indices for stiffness performance evaluation

Giuseppe CARBONE, Marco CECCARELLI,

期刊论文