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Optimal dispatch of multi energy system using power-to-gas technology considering flexible load on user

Zi LING, Xiu YANG, Zilin LI

《能源前沿(英文)》 2018年 第12卷 第4期   页码 569-581 doi: 10.1007/s11708-018-0595-6

摘要:

The relation between power-to-gas technology (P2G) and energy interconnection becomes increasingly close. Meanwhile, the participation of flexible load on user side in system optimization has attracted much attention as an efficient approach to relieve the contradiction between energy supply and energy demand. Based on the concept of energy hub, according to its series characteristic, this paper established a generic multi-energy system model using the P2G technology. The characteristic of flexible load on user side was considered and optimal dispatch analysis was made, so as to reduce the cost, to reasonably dispatch the flexible load, to reduce the discharge, to enhance the new energy output, and to increase the power-to-gas conversion efficiency. Finally, a concrete analysis was made on the optimal dispatch result of the multi-energy system using the P2G technology considering flexible load on user side in the calculating example, and optimal dispatch of the system was verified via four different scenarios. The results indicate that cooperative dispatch of multi-energy system using the P2G technology considering flexible load on user side is the most economic, and can make a contribution to absorption of new energy and P2G conversion. In this way, environmental effects and safe and stable operation of the system can be guaranteed.

关键词: multi-energy system     energy hub     series characteristic     optimal dispatch     flexible load    

柔性材料对爆炸载荷的缓冲效应研究

于少娟,李永池,刘颢文,孙宇新,胡秀章

《中国工程科学》 2007年 第9卷 第4期   页码 75-78

摘要:

建立了柔性材料桙钢复合壳体在爆炸载荷作用下应力波传播问题的完备方程组;使用有限元方法完成 了对复合壳体在爆炸载荷作用下应力波传播规律的系列数值模拟,并着重讨论了不同炸药层和柔性材料层厚度 对柔性材料与钢交界面载荷的影响。

关键词: 柔性材料     爆炸载荷     载荷改造     数值模拟    

Impact of renewable energies on the operation and economic situation of coal fired power stations: Actual situation of coal fired power stations in Germany

Hans-Joachim KRAUTZ, Alexander LISK, Joachim POSSELT, Christian KATZER

《能源前沿(英文)》 2017年 第11卷 第2期   页码 119-125 doi: 10.1007/s11708-017-0468-4

摘要: Due to the fluctuating character of the renewable energy sources the demand of conventional power plants for flexibility is increasing. In the recent years, in Germany there has been a fast rise of production capacity of renewable energies, especially from wind turbines, photovoltaic installations, and biomass plants. The installed nominal power of wind turbines is actually (December 2016) 42 GW and of photovoltaic installations 40?GW. The renewable electric energy production in Germany is about 190?TWh/a, which represents a share of 33% of the yearly demand. The increased need for flexibility affects both the power gradients as well as the minimum load of conventional power plants. Due to this flexibility behaviour, conventional power plants are faced with problems concerning the durability of power plant components, corrosion, more maintenance effort and consequently the overall life expectancy. Another consequence of the increasing share of renewable energies is the decreasing full load operating hours, especially of coal fired and gas power plants. Along with decreasing revenues from the energy exchange market, coal fired power plants are faced with new economically challenges.

关键词: flexible load operation     minimal load     power gradients     power plant maintenance     corrosion     life expectancy    

Piezoelectric pump with flexible venous valves for active cell transmission

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0712-4

摘要: The development of organ-on-a-chip systems demands high requirements for adequate micro-pump performance, which needs excellent performance and effective transport of active cells. In this study, we designed a piezoelectric pump with a flexible venous valve inspired by that of humans. Performance test of the proposed pump with deionized water as the transmission medium shows a maximum output flow rate of 14.95 mL/min when the input voltage is 100 V, and the pump can transfer aqueous solutions of glycerol with a viscosity of 10.8 mPa·s. Cell survival rate can reach 97.22% with a yeast cell culture solution as the transmission medium. A computational model of the electric-solid-liquid multi-physical field coupling of the piezoelectric pump with a flexible venous valve is established, and simulation results are consistent with experimental results. The proposed pump can help to construct the circulating organ-on-a-chip system, and the simple structure and portable application can enrich the design of microfluidic systems. In addition, the multi-physical field coupling computational model established for the proposed piezoelectric pump can provide an in-depth study of the characteristics of the flow field, facilitating the optimal design of the micro-pump and providing a reference for the further study of active cell transport in organ-on-a-chip systems.

关键词: venous valve     flexible venous valve     cell transmission     organ-on-a-chip system     piezoelectric device    

Creation and integration mechanism of instrumentation flexible developing system

Xiaoli XU, Qiushuang LIU

《机械工程前沿(英文)》 2011年 第6卷 第2期   页码 235-240 doi: 10.1007/s11465-011-0122-5

摘要:

To solve many key technical problems during the development of modern instrumentation system integration and provide a new mode and fundamental technical equipment for the research and development (R&D) of modern instrumentation products, based on the concept of an instrumentation flexible developing system (IFDS), this paper discusses the creation and open flexible integration mechanism, perfects the integrated supporting environment and integrated system of the flexible interconnection, and constructs the new flexible integrated system. Based on the operation mechanism of the modern instrumentation developing system and the research and optimization of the rapid integration design method, the paper emphasizes the dynamic integrating method of multiple types of knowledge in a modern instrument R&D system, to effectively utilize the rich integrated resource and achieve rapid integration of the system. Applications show that the new IFDS can improve the integration level and efficiency of R&D of the modern instrumentation system, enforce the reliability of the system, shorten the R&D period, and reduce the development costs.

关键词: modern instrumentation developing     flexible interconnection     flexible integration mechanism     rapid integration system     dynamic integrating method    

Review on flexible perovskite photodetector: processing and applications

《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-023-0749-z

摘要: Next-generation optoelectronics should possess lightweight and flexible characteristics, thus conforming to various types of surfaces or human skins for portable and wearable applications. Flexible photodetectors as fundamental devices have been receiving increasing attention owing to their potential applications in artificial intelligence, aerospace industry, and wise information technology of 120, among which perovskite is a promising candidate as the light-harvesting material for its outstanding optical and electrical properties, remarkable mechanical flexibility, low-cost and low-temperature processing methods. To date, most of the reports have demonstrated the fabrication methods of the perovskite materials, materials engineering, applications in solar cells, light-emitting diodes, lasers, and photodetectors, strategies for device performance enhancement, few can be seen with a focus on the processing strategies of perovskite-based flexible photodetectors, which we will give a comprehensive summary, herein. To begin with, a brief introduction to the fabrication methods of perovskite (solution and vapor-based methods), device configurations (photovoltaic, photoconductor, and phototransistor), and performance parameters of the perovskite-based photodetectors are first arranged. Emphatically, processing strategies for photodetectors are presented following, including flexible substrates (i.e., polymer, carbon cloth, fiber, paper, etc.), soft electrodes (i.e., metal-based conductive networks, carbon-based conductive materials, and two-dimensional (2D) conductive materials, etc.), conformal encapsulation (single-layer and multilayer stacked encapsulation), low-dimensional perovskites (0D, 1D, and 2D nanostructures), and elaborate device structures. Typical applications of perovskite-based flexible photodetectors such as optical communication, image sensing, and health monitoring are further exhibited to learn the flexible photodetectors on a deeper level. Challenges and future research directions of perovskite-based flexible photodetectors are proposed in the end. The purpose of this review is not only to shed light on the basic design principle of flexible photodetectors, but also to serve as the roadmap for further developments of flexible photodetectors and exploring their applications in the fields of industrial manufacturing, human life, and health care.

关键词: photodetector     perovskite     flexible     processing     application    

A review of the scalable nano-manufacturing technology for flexible devices

Wenbin HUANG,Xingtao YU,Yanhua LIU,Wen QIAO,Linsen CHEN

《机械工程前沿(英文)》 2017年 第12卷 第1期   页码 99-109 doi: 10.1007/s11465-017-0416-3

摘要:

Recent advances in electronic and photonic devices, such as artificial skin, wearable systems, organic and inorganic light-emitting diodes, have gained considerable commercial and scientific interest in the academe and in industries. However, low-cost and high-throughput nano-manufacturing is difficult to realize with the use of traditional photolithographic processes. In this review, we summarize the status and the limitations of current nano-patterning techniques for scalable and flexible functional devices in terms of working principle, resolution, and processing speed. Finally, several remaining unsolved problems in nano-manufacturing are discussed, and future research directions are highlighted.

关键词: flexible nano-manufacturing     flexible devices     nanofabrication     scalability    

Analytical dynamic solution of a flexible cable-suspended manipulator

Mahdi BAMDAD

《机械工程前沿(英文)》 2013年 第8卷 第4期   页码 350-359 doi: 10.1007/s11465-013-0271-9

摘要:

Cable-suspended manipulators are used in large scale applications with, heavy in weight and long in span cables. It seems impractical to maintain cable assumptions of smaller robots for large scale manipulators. The interactions among the cables, platforms and actuators can fully evaluate the coupled dynamic analysis. The structural flexibility of the cables becomes more pronounced in large manipulators. In this paper, an analytic solution is provided to solve cable vibration. Also, a closed form solution can be adopted to improve the dynamic response to flexibility. The output is provided by the optimal torque generation subject to the actuator limitations in a mechatronic sense. Finally, the performance of the proposed algorithm is examined through simulations.

关键词: parallel robot     flexible cable     suspended robot     dynamic    

Possible role of power-to-heat and power-to-gas as flexible loads in German medium voltage networks

Mark KUPRAT, Martin BENDIG, Klaus PFEIFFER

《能源前沿(英文)》 2017年 第11卷 第2期   页码 135-145 doi: 10.1007/s11708-017-0472-8

摘要: Germany’s energy transition triggered a rapid and unilateral growth of renewable energy sources (RES) in the electricity sector. With increasing shares of intermittent RES, overcapacities during periods of strong wind and photovoltaic electricity generation occur. In the face of insufficient transmission capacities, due to an inhibited network extension, the electricity generation has to be curtailed. This curtailment of RES leads to economic losses and could be avoided through flexible loads. As an option to cope with those problems, the technologies of power-to-gas (PtG) and power-to-heat (PtH) are presented in this paper. First, the alkaline electrolyzer (AEL), polymer electrolyte membrane electrolyzer (PEMEL), and solid oxide electrolyzer cell (SOEC) are investigated regarding their operational parameters. Second, the electric boiler, electrode heating boiler, and heat pumps are considered. Ultimately, the network-supporting abilities and the potential to provide ancillary services, such as control power, load sequence operation, cold start and part load capability, are compared among one another.

关键词: power-to-gas     power-to-heat     flexible loads     ancillary services     coherent energy systems    

复合柔性结构航天器动力学建模研究

曲广吉,程道生

《中国工程科学》 1999年 第1卷 第2期   页码 52-56

摘要:

柔性航天器动力学建模的传统方法是采用混合坐标法,针对中心刚体带大型柔性附件类的航天器,这种方法在理论建模和工程应用方面都获得了极大的成功。在中心刚体加柔性附件类航天器柔性动力学研究成果基础上,通过计及柔性体与柔性体连接点间的复合位移变形,利用混合坐标法建立了复合柔性结构航天器动力学模型,其软件系统DASFA 2.0已初步用于工程分析设计。

关键词: 航天器     复合柔性结构     柔性动力学     混合坐标法    

Estimation of flexible pavement structural capacity using machine learning techniques

Nader KARBALLAEEZADEH, Hosein GHASEMZADEH TEHRANI, Danial MOHAMMADZADEH SHADMEHRI, Shahaboddin SHAMSHIRBAND

《结构与土木工程前沿(英文)》 2020年 第14卷 第5期   页码 1083-1096 doi: 10.1007/s11709-020-0654-z

摘要: The most common index for representing structural condition of the pavement is the structural number. The current procedure for determining structural numbers involves utilizing falling weight deflectometer and ground-penetrating radar tests, recording pavement surface deflections, and analyzing recorded deflections by back-calculation manners. This procedure has two drawbacks: falling weight deflectometer and ground-penetrating radar are expensive tests; back-calculation ways has some inherent shortcomings compared to exact methods as they adopt a trial and error approach. In this study, three machine learning methods entitled Gaussian process regression, M5P model tree, and random forest used for the prediction of structural numbers in flexible pavements. Dataset of this paper is related to 759 flexible pavement sections at Semnan and Khuzestan provinces in Iran and includes “structural number” as output and “surface deflections and surface temperature” as inputs. The accuracy of results was examined based on three criteria of , , and . Among the methods employed in this paper, random forest is the most accurate as it yields the best values for above criteria ( =0.841, =0.592, and =0.760). The proposed method does not require to use ground penetrating radar test, which in turn reduce costs and work difficulty. Using machine learning methods instead of back-calculation improves the calculation process quality and accuracy.

关键词: transportation infrastructure     flexible pavement     structural number prediction     Gaussian process regression     M5P model tree     random forest    

Estimation of composite load model with aggregate induction motor dynamic load for an isolated hybrid

Nitin Kumar SAXENA,Ashwani Kumar SHARMA

《能源前沿(英文)》 2015年 第9卷 第4期   页码 472-485 doi: 10.1007/s11708-015-0373-7

摘要: It is well recognized that the voltage stability of a power system is affected by the load model and hence, to effectively analyze the reactive power compensation of an isolated hybrid wind-diesel based power system, the loads need to be considered along with the generators in a transient analysis. This paper gives a detailed mathematical modeling to compute the reactive power response with small voltage perturbation for composite load. The composite load is a combination of the static and dynamic load model. To develop this composite load model, the exponential load is used as a static load model and induction motors (IMs) are used as a dynamic load model. To analyze the dynamics of IM load, the fifth, third and first order model of IM are formulated and compared using differential equations solver in Matlab coding. Since the decentralized areas have many small consumers which may consist large numbers of IMs of small rating, it is not realistic to model either a single large rating unit or all small rating IMs together that are placed in the system. In place of using a single large rating IM, a group of motors are considered and then the aggregate model of IM is developed using the law of energy conservation. This aggregate model is used as a dynamic load model. For different simulation studies, especially in the area of voltage stability with reactive power compensation of an isolated hybrid power system, the transfer function of the composite load is required. The transfer function of the composite load is derived in this paper by successive derivation for the exponential model of static load and for the fifth and third order IM dynamic load model using state space model.

关键词: isolated hybrid power system (IHPS)     composite load model     static load     dynamic load     induction motor load model     aggregate load    

Design and applications of morphing aircraft and their structures

《机械工程前沿(英文)》 2023年 第18卷 第3期 doi: 10.1007/s11465-023-0750-6

摘要: Morphing aircraft can adaptively regulate their aerodynamic layout to meet the demands of varying flight conditions, improve their aerodynamic efficiency, and reduce their energy consumption. The design and fabrication of high-performance, lightweight, and intelligent morphing structures have become a hot topic in advanced aircraft design. This paper discusses morphing aircraft development history, structural characteristics, existing applications, and future prospects. First, some conventional mechanical morphing aircraft are examined with focus on their morphing modes, mechanisms, advantages, and disadvantages. Second, the novel applications of several technologies for morphing unmanned aerial vehicles, including additive manufacturing for fabricating complex morphing structures, lattice technology for reducing structural weight, and multi-mode morphing combined with flexible skins and foldable structures, are summarized and categorized. Moreover, in consideration of the further development of active morphing aircraft, the paper reviews morphing structures driven by smart material actuators, such as shape memory alloy and macro-fiber composites, and analyzes their advantages and limitations. Third, the paper discusses multiple challenges, including flexible structures, flexible skins, and control systems, in the design of future morphing aircraft. Lastly, the development and application of morphing structures in the aerospace field are discussed to provide a reference for future research and engineering applications.

关键词: morphing aircraft     additive manufacturing     lattice structure     smart material     flexible structure     flexible skin    

A pseudocapacitive molecule-induced strategy to construct flexible high-performance asymmetric supercapacitors

《化学科学与工程前沿(英文)》 2023年 第17卷 第9期   页码 1208-1220 doi: 10.1007/s11705-023-2304-1

摘要: The combination of high-voltage windows and bending stability remains a challenge for supercapacitors. Here, we present an “advantage-complementary strategy” using sodium lignosulfonate as a pseudocapacitive molecule to regulate the spatial stacking pattern of graphene oxide and the interfacial architectures of graphene oxide and polyaniline. Flexible and sustainable sodium lignosulfonate-based electrodes are successfully developed, showing perfect bending stability and high electronic conductivity and specific capacitance (521 F·g−1 at 0.5 A·g–1). Due to the resulting rational interfacial structure and stable ion-electron transport, the asymmetric supercapacitors provide a wide voltage window reaching 1.7 V, outstanding bending stability and high energy-power density of 83.87 Wh·kg–1 at 3.4 kW·kg–1. These properties are superior to other reported cases of asymmetric energy enrichment. The synergistic strategy of sodium lignosulfonate on graphene oxide and polyaniline is undoubtedly beneficial to advance the process for the construction of green flexible supercapacitors with remarkably wide voltage windows and excellent bending stability.

关键词: molecular synergy     pseudocapacitive lignosulfonate     flexible electronic devices     asymmetric supercapacitor     wide voltage windows    

Implementation of a flexible Major Vacation Toll-free Program for small passenger vehicles in China

Meng XU, Ziyou GAO

《工程管理前沿(英文)》 2017年 第4卷 第4期   页码 498-499 doi: 10.15302/J-FEM-2017111

标题 作者 时间 类型 操作

Optimal dispatch of multi energy system using power-to-gas technology considering flexible load on user

Zi LING, Xiu YANG, Zilin LI

期刊论文

柔性材料对爆炸载荷的缓冲效应研究

于少娟,李永池,刘颢文,孙宇新,胡秀章

期刊论文

Impact of renewable energies on the operation and economic situation of coal fired power stations: Actual situation of coal fired power stations in Germany

Hans-Joachim KRAUTZ, Alexander LISK, Joachim POSSELT, Christian KATZER

期刊论文

Piezoelectric pump with flexible venous valves for active cell transmission

期刊论文

Creation and integration mechanism of instrumentation flexible developing system

Xiaoli XU, Qiushuang LIU

期刊论文

Review on flexible perovskite photodetector: processing and applications

期刊论文

A review of the scalable nano-manufacturing technology for flexible devices

Wenbin HUANG,Xingtao YU,Yanhua LIU,Wen QIAO,Linsen CHEN

期刊论文

Analytical dynamic solution of a flexible cable-suspended manipulator

Mahdi BAMDAD

期刊论文

Possible role of power-to-heat and power-to-gas as flexible loads in German medium voltage networks

Mark KUPRAT, Martin BENDIG, Klaus PFEIFFER

期刊论文

复合柔性结构航天器动力学建模研究

曲广吉,程道生

期刊论文

Estimation of flexible pavement structural capacity using machine learning techniques

Nader KARBALLAEEZADEH, Hosein GHASEMZADEH TEHRANI, Danial MOHAMMADZADEH SHADMEHRI, Shahaboddin SHAMSHIRBAND

期刊论文

Estimation of composite load model with aggregate induction motor dynamic load for an isolated hybrid

Nitin Kumar SAXENA,Ashwani Kumar SHARMA

期刊论文

Design and applications of morphing aircraft and their structures

期刊论文

A pseudocapacitive molecule-induced strategy to construct flexible high-performance asymmetric supercapacitors

期刊论文

Implementation of a flexible Major Vacation Toll-free Program for small passenger vehicles in China

Meng XU, Ziyou GAO

期刊论文