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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

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Whole-life Thinking and Engineering the Future

Roger Flanagan

《工程管理前沿（英文）》 2014年第1卷第3期页码 290-296 doi: 10.15302/J-FEM-2014040

摘要： Whole-life thinking for engineers working on the built environment has become more important in a fast changing world. Whole-life thinking is not new, every project attempts to balance the initial capital cost with the operating and maintenance cost of an asset. Engineers are increasingly concerned with complex systems, in which the parts interact with each other and with the outside world in many ways — the relationships between the parts determine how the system behaves. Systems thinking provides one approach to developing a more robust whole-life approach. Systems thinking is a process of understanding how things influence one another within a wider perspective. Complexity, chaos, and risk are endemic in all major projects. New approaches are needed to produce more reliable whole-life predictions. Best value, rather than lowest cost, can be achieved by using whole-life appraisal as a part of the design and delivery strategy.

关键词： whole-life thinking systems thinking complexity chaos risk management through life

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基于飞机结构寿命包线的飞机结构单机寿命监控

何宇廷

《中国工程科学》 2006年第8卷第6期页码 23-27

摘要：

在分析基准使用条件下飞机结构寿命包线的基础上，给出飞机结构在非基准使用条件下的寿命包线的绘制方法，阐明了在非基准使用条件下对飞机结构进行单机寿命监控的原理与方法。最后以飞机首翻后进行第二次大修的大修间隔期监控为例进行了分析说明。

关键词：飞机结构寿命包线寿命监控大修间隔期

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Comparison on End-of-Life strategies of WEEE in China based on LCA

Bin Lu, Xiaolong Song, Jianxin Yang, Dong Yang

《环境科学与工程前沿（英文）》 2017年第11卷第5期 doi: 10.1007/s11783-017-0994-7

摘要： As the Electrical and Electronic Equipment (EEE) are upgraded more frequently in China, a large quantity of Waste Electrical and Electronic Equipment (WEEE) was and will be generated. It becomes an urgent issue to develop and adopt an effective End-of-Life (EoL) strategy for EEE in order to balance the resource recovery and environmental impacts. In an EoL strategy hierarchy for EEE, reuse strategy is usually deemed to be prior to materials recovery and other strategies. But in practice, the advantages and disadvantages of different strategies are always context-dependent. Therefore, main EoL strategies for EEE in China need to be evaluated in environment and resources aspects from the life cycle perspective. In this study, the obsolete refrigerator and Power Supply Unit (PSU) of desktop PC are both taken as the target products. Life Cycle Assessment (LCA) is applied to assess the environmental impacts of different EoL scenarios in China: Unit Reuse Scenario (URS), Component Reuse Scenario (CRS) and Materials Recovery Scenario (MRS). The LCA results show that the EoL strategies hierarchy is reasonable for the part of computer, but not necessarily suitable for obsolete refrigerators. When the policy makers promote or demote one EoL strategy especially reuse, it is necessary to take subsequent impacts into consideration.

关键词： End-of-Life Waste electrical and electronic equipment Life cycle assessment Reuse

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Bayes estimation of residual life by fusing multisource information

Qian ZHAO, Xiang JIA, Zhi-jun CHENG, Bo GUO

《工程管理前沿（英文）》 2018年第5卷第4期页码 524-532 doi: 10.15302/J-FEM-2018034

摘要：

Residual life estimation is essential for reliability engineering. Traditional methods may experience difficulties in estimating the residual life of products with high reliability, long life, and small sample. The Bayes model provides a feasible solution and can be a useful tool for fusing multisource information. In this study, a Bayes model is proposed to estimate the residual life of products by fusing expert knowledge, degradation data, and lifetime data. The linear Wiener process is used to model degradation data, whereas lifetime data are described via the inverse Gaussian distribution. Therefore, the joint maximum likelihood (ML) function can be obtained by combining lifetime and degradation data. Expert knowledge is used according to the maximum entropy method to determine the prior distributions of parameters, thereby making this work different from existing studies that use non-informative prior. The discussion and analysis of different types of expert knowledge also distinguish our research from others. Expert knowledge can be classified into three categories according to practical engineering. Methods for determining prior distribution by using the aforementioned three types of data are presented. The Markov chain Monte Carlo is applied to obtain samples of the parameters and to estimate the residual life of products due to the complexity of the joint ML function and the posterior distribution of parameters. Finally, a numerical example is presented. The effectiveness and practicability of the proposed method are validated by comparing it with residual life estimation that uses non-informative prior. Then, its accuracy and correctness are proven via simulation experiments.

关键词： residual life estimation Bayes model linear Wiener process

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A comparison of production system life cycle models

Rajesh ATTRI, Sandeep GROVER

《机械工程前沿（英文）》 2012年第7卷第3期页码 305-311 doi: 10.1007/s11465-012-0332-5

摘要：

Companies today need to keep up with the rapidly changing market conditions to stay competitive. The main issues in this paper are related to a company’s market and its competitors. The prediction of market behavior is helpful for a manufacturing enterprise to build efficient production systems. However, these predictions are usually not reliable. A production system is required to adapt to changing markets, but such requirement entails higher cost. Hence, analyzing different life cycle models of the production system is necessary. In this paper, different life cycle models of the production system are compared to evaluate the distinctive features and the limitations of each model. Furthermore, the difference between product life cycle and production life cycle is summarized, and the effect of product life cycle on production life cycle is explained. Finally, a production system life cycle model, along with key activities to be performed in each stage, is proposed specifically for the manufacturing sector.

关键词： production system life cycle model product

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General framework for bridge life cycle design

Junhai MA, Airong CHEN, Jun HE

《结构与土木工程前沿（英文）》 2009年第3卷第1期页码 50-56 doi: 10.1007/s11709-009-0004-7

摘要： Based on a detailed illustration for bridge life cycle design which comprises the processes of service life design, aesthetics design, performance design, environmental and ecological design, inspection, maintenance and repair design as well as cost analysis, this paper presented a general framework for bridge life cycle design comprising three design phases and six design processes.

关键词： bridge whole life design design phase design process general framework

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Chemically triggered life control of “smart” hydrogels through click and declick reactions

《化学科学与工程前沿（英文）》 2022年第16卷第9期页码 1399-1406 doi: 10.1007/s11705-022-2149-z

摘要： The degradation of polymeric materials is recognized as one of the goals to be fulfilled for the sustainable economy. In this study, a novel methodology was presented to synthesize multiple highly cross-linked polymers (i.e., hydrogels) through amine–thiol scrambling under mild conditions. Amine-terminated poly(ethylene glycol) (PEG-NH₂) was reacted with the representative conjugate acceptors to synthesize hydrogels in organic and aqueous solutions, respectively. The materials above exhibited high water-swelling properties, distributed porous structures, as well as prominent mechanical strengths. It is noteworthy that the mentioned hydrogels could be degraded efficiently in hours to release the original coupling partner, which were induced by ethylene diamine at ambient temperature through amine-amine metathesis. The recovered PEG-NH₂ reagent could be employed again to regenerate hydrogels. Due to the multiple architectures and functions in polymeric synthesis, degradation and regeneration, a new generation of “smart” materials is revealed.

关键词： hydrogels degradation synthesis regeneration

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State-of-the-art applications of machine learning in the life cycle of solid waste management

《环境科学与工程前沿（英文）》 2023年第17卷第4期 doi: 10.1007/s11783-023-1644-x

摘要：

● State-of-the-art applications of machine learning (ML) in solid waste (SW) is presented.

关键词： Machine learning (ML) Solid waste (SW) Bibliometrics SW management Energy utilization Life cycle

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Service life prediction of fly ash concrete using an artificial neural network

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 793-805 doi: 10.1007/s11709-021-0717-9

摘要： Carbonation is one of the most aggressive phenomena affecting reinforced concrete structures and causing their degradation over time. Once reinforcement is altered by carbonation, the structure will no longer fulfill service requirements. For this purpose, the present work estimates the lifetime of fly ash concrete by developing a carbonation depth prediction model that uses an artificial neural network technique. A collection of 300 data points was made from experimental results available in the published literature. Backpropagation training of a three-layer perceptron was selected for the calculation of weights and biases of the network to reach the desired performance. Six parameters affecting carbonation were used as input neurons: binder content, fly ash substitution rate, water/binder ratio, CO₂ concentration, relative humidity, and concrete age. Moreover, experimental validation carried out for the developed model shows that the artificial neural network has strong potential as a feasible tool to accurately predict the carbonation depth of fly ash concrete. Finally, a mathematical formula is proposed that can be used to successfully estimate the service life of fly ash concrete.

关键词： concrete fly ash carbonation neural networks experimental validation service life

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An updated review and conceptual model for optimizing WEEE management in China from a life cycle perspective

Xiaolong Song, Jingwei Wang, Jianxin Yang, Bin Lu

《环境科学与工程前沿（英文）》 2017年第11卷第5期 doi: 10.1007/s11783-017-0985-8

摘要： Waste electrical and electronic equipment (WEEE) is a rapidly growing category of solid waste. China is now facing WEEE problems from both growing domestic generation and illegal imports. Currently, the amount of WEEE formally treated has increased steadily in China. The layout of the formal sector has been basically completed. Meanwhile, by controlling illegal disassembly activities, the informal sector has been gradually transformed to formal one. Beginning with the overview of the WEEE recycling industry in China, this paper first lists the latest progress in WEEE management from such aspects as the new edition of China RoHS Directive (Restriction of Hazardous Substances Directive), the updated WEEE Treatment List, the updated WEEE fund standard, the revised National Hazardous Waste List, and a brand-new plan on extended producer responsibility. In so doing, we elucidate the current challenges on WEEE management in detail: the imbalance between fund levies and subsidies, the gap in the supervision scope, the homogenization of recycling industry and the lack of life cycle approaches. Finally, a conceptual framework for integrated management of WEEE is proposed from a life cycle perspective. Overall, the life cycle management of WEEE includes three aspects: developing life cycle information for decision-making, implementing life cycle engineering with life cycle tools, and improving WEEE legislation based on life cycle thinking. By providing specific operating strategies, this life cycle framework should help to optimize WEEE management in developing countries where legislation is imperfect and the recycling system is relatively immature.

关键词： Waste electrical and electronic equipment E-waste Life cycle management China

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Creep life assessment of aero-engine recuperator based on continuum damage mechanics approach

《机械工程前沿（英文）》 2022年第17卷第4期 doi: 10.1007/s11465-022-0702-6

摘要： The creep life of an aeroengine recuperator is investigated in terms of continuum damage mechanics by using finite element simulations. The effects of the manifold wall thickness and creep properties of brazing filler metal on the operating life of the recuperator are analyzed. Results show that the crack initiates from the brazing filler metal located on the outer surface of the manifold with the wall thickness of 2 mm and propagates throughout the whole region of the brazing filler metal when the creep time reaches 34900 h. The creep life of the recuperator meets the requirement of 40000 h continuous operation when the wall thickness increases to 3.5 mm, but its total weight increases by 15%. Decreasing the minimum creep strain rate with the enhancement of the creep strength of the brazing filler metal presents an obvious effect on the creep life of the recuperator. At the same stress level, the creep rupture time of the recuperator is enhanced by 13 times if the mismatch between the minimum creep rate of the filler and base metal is reduced by 20%.

关键词： creep life assessment brazed joint continuum damage mechanics aeroengine recuperator

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Accelerated life-time test of MEA durability under vehicle operating conditions in PEM fuel cell

Tian TIAN, Jianjun TANG, Wei GUO, Mu PAN

《能源前沿（英文）》 2017年第11卷第3期页码 326-333 doi: 10.1007/s11708-017-0489-z

摘要： In this paper, a novel accelerated test method was proposed to analyze the durability of MEA, considering the actual operation of the fuel cell vehicle. The proposed method includes 7 working conditions: open circuit voltage (OCV), idling, rated output, overload, idling-rated cycle, idling-overload cycle, and OCV-idling cycle. The experimental results indicate that the proposed method can effectively destroy the MEA in a short time (165 h). Moreover, the degradation mechanism of MEA was analyzed by measuring the polarization curve, CV, SEM and TEM. This paper may provide a new research direction for improving the durability of fuel cell.

关键词： polymer electrolyte membrane fuel cell accelerated life-time test load cycling test durability

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Clustering economic sectors in China on a life cycle basis to achieve environmental sustainability

Sai LIANG, Tianzhu ZHANG, Xiaoping JIA

《环境科学与工程前沿（英文）》 2013年第7卷第1期页码 97-108 doi: 10.1007/s11783-012-0402-2

摘要： To improve material efficiency, industrial structure optimization becomes a focal point in Chinese industrial and environmental policies. It is crucial to cluster economic sectors and determine their priority for industrial and environmental policy implementation. Integrating a set of criteria, a hybrid input-output model and the hierarchical cluster analysis, this study clusters China’s economic sectors and determines their priority on a life cycle basis. China’s economic sectors are clustered into three clusters. Industrial structure changes (industrial policy) should encourage the development of sectors in cluster 1 and limit the development of sectors in cluster 2. Technology development and materials recycling (two environmental policies) should mainly focus on sectors in clusters 1 and 2. Future industrial policies in China should limit the development of two sectors named and . Instead of limiting some industries by command-and-control, the best policy option is to remedy environmental standards and law enforcement. Enterprises belonging to the identified key sectors from the viewpoint of direct production impacts should be concerned to achieve enterprise sustainability. To achieve sustainable production chains, the identified key sectors from the viewpoint of accumulative production impacts should be concerned. For sustainable consumption, the identified key sectors from the viewpoint of consumption impacts should be concerned to transform consumption styles. Most of environmental pressure can be alleviated not only by technical improvements and material recycling, but also by the development of economic sectors in cluster 1.

关键词： cluster analysis input-output model life cycle material flow analysis sustainable development

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Assessment of fatigue life of remanufactured impeller based on FEA

Lei XU,Huajun CAO,Hailong LIU,Yubo ZHANG

《机械工程前沿（英文）》 2016年第11卷第3期页码 219-226 doi: 10.1007/s11465-016-0394-x

摘要：

Predicting the fatigue life of remanufactured centrifugal compressor impellers is a critical problem. In this paper, the S-N curve data were obtained by combining experimentation and theory deduction. The load spectrum was compiled by the rain-flow counting method based on the comprehensive consideration of the centrifugal force, residual stress, and aerodynamic loads in the repair region. A fatigue life simulation model was built, and fatigue life was analyzed based on the fatigue cumulative damage rule. Although incapable of providing a high-precision prediction, the simulation results were useful for the analysis of fatigue life impact factors and fatigue fracture areas. Results showed that the load amplitude greatly affected fatigue life, the impeller was protected from running at over-speed, and the predicted fatigue life was satisfied within the next service cycle safely at the rated speed.

关键词： remanufactured impeller fatigue life impeller failures finite element analysis (FEA)

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标题作者时间类型操作

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

Whole-life Thinking and Engineering the Future

Roger Flanagan

期刊论文

基于飞机结构寿命包线的飞机结构单机寿命监控

何宇廷

期刊论文

Comparison on End-of-Life strategies of WEEE in China based on LCA

Bin Lu, Xiaolong Song, Jianxin Yang, Dong Yang

期刊论文

Bayes estimation of residual life by fusing multisource information