Carbon weight analysis for machining operation and allocation for redesign

The objective of this research paper is to explore and develop a new methodology for computing carbon weight (CW) – often referred to as carbon footprint, in manufacturing processes from part level to assembly level. In this initial study, we focused on machining operations, specifically turning and milling, for computing CW. Our initial study demonstrates that CW can be computed using either actual measured data from process level information or from initial material and manufacturing process information. In mechanical design, tolerance analysis principles extend from design to manufacturing and tolerances accumulate for parts and processes. By extending this notion to CW, we apply mechanical tolerancing principles for computing worst case and statistical case CW of a product. We call this the CW tolerance approach (CWTA). Two case studies demonstrate the computation of CW. Based on the tolerance allocation concepts; CW allocation is also demonstrated through specific redesign examples. CWTA helps in identifying carbon intensive parts/processes and can be used to make appropriate design decisions.     

Construction of an optimum system design method considering product lifecycle

This paper proposes an optimum system design method that especially considers product lifecycles and aims to help designers make effective decisions during the product design phase. By considering and estimating all lifecycle factors of cost and environmental impact in addition to the product performance, this method facilitates development of optimum design solutions that incorporate requirements pertaining to the product's entire lifecycle. Furthermore, quantitative estimation of lifecycle factors enables the numerical expression of optimum solutions, rather than depending primarily on experiment and designer intuition. To demonstrate the effectiveness of the proposed method, this paper develops an optimum system design method for a milling machine as an example of a machine product designed for long term use. The lifecycle cost and the lifecycle environmental impact are generally expressed as the summation of each value during manufacturing phase, usage phase, disposal phase and recycling phase. In this example model, Eco-indicator 99 is used to evaluate environmental impact. In the proposed lifecycle design optimisation method, the relationships among the product performance, the lifecycle cost and the lifecycle environmental impact are evaluated as a multi-objective optimisation problem. Analysis of the obtained Pareto optimum solution sets subsequently enables designers to pursue breakthrough product design solutions.     

Multiobjective optimisation method for life-cycle design of mechanical products

Manufacturing that minimises the exhaustion of natural resources, energy used and deleterious environmental impact is increasingly demanded by societies that seek to protect global environments as much as possible. To achieve this, life-cycle design (LCD) is an essential component of product design scenarios; however, LCD approaches have not been well integrated in optimal design methods that support quantitative decision-making. This study presents a method that yields quantitative solutions through optimisation analysis of a basic product design incorporating life-cycle considerations. We consider two types of optimisation approaches that have different aims, namely, (1) to reduce the use of raw materials and energy consumption and (2) to facilitate the reuse of the product or its parts when it reaches the end of its useful life. We also focus on how the optimisation results differ according to the approach used, from the viewpoint of the 3R concept (Reduce, Reuse and Recycling). Our method obtains optimum solutions by evaluating objectives fitted to each of these two optimisation approaches with respect to the product's life-cycle stages, which are manufacturing, use, maintenance, disposal, reuse and recycling. As an applied example, a simple linear robot model is presented, and Pareto optimum solutions are obtained for the multiobjective optimisation problem whose evaluated objectives are the operating accuracy of the robot and the different life-cycle costs for the two approaches. The characteristics of the evaluated objectives and design variables, as well as the effects of using material characteristics as design parameters, are also examined.     

Synergico: a method for systematic integration of energy efficiency into the design process of electr(on)ic equipment

This paper presents an overall design method to better consider the energy consumption of electrical and electronic equipment during the use phase. This aspect is often considered as the most important environmental aspect in active electrical and electronic equipment during its life cycle. The proposed method, called ‘Synergico’, characterises the product energy efficiency according to its modes, its functions and its sub-assemblies. It also articulates three tools: one assessment tool, one improvement tool and one environmental check tool. These tools are integrated along a typical product design process. The method therefore helps designing more energy-efficient products without compromising other performances such as ergonomics, functional performances, security, recyclability or costs. The three tools and the overall method are presented. A case study illustrates the way it works and is discussed.     

CAD and DFM: enablers of sustainable product design

Sustainability has been regarded as an important concept for survival in the contemporary scenario. Modern design engineers are in need of approaches for creating sustainable products. In this context, this paper reports a case study carried out in an Indian modular switches manufacturing organisation. The existing handle of the switch has been modelled using computer-aided design (CAD). Then, the sustainability analysis has been carried out for determining the environmental impact. This is followed by the redesign of the handle using design for manufacturability (DFM) principles. The sustainability has been measured in terms of carbon footprint, energy consumption and air–water impacts. It has been found that the redesigned handle possesses minimal environmental impact. It could be inferred from the results of the case study that CAD and DFM could lead to the development of sustainable product design with minimal impact on the environment.     

An enhanced sustainable approach for design and manufacturing with an application to fuselages for mono-seat civil sailplanes

Abstract

A number of tools and software systems have been developed in order to reduce the time for the design and manufacturing of industrial products. Nowadays, virtual modelling by Computer Aided Design (CAD) systems and process simulation by the application of Finite Element Method (FEM) software is a standard routine in order to compress product design activities and to achieve the optimal solution before producing any real components. These developments provided not only a reduction in the time to market but a higher complexity of the project and an improved quality of the industrial products. With the aim to further improve the sustainability of this activity, the implementation of a tool that adds automatic operations into the design activity is demonstrated. This software can interact with any CAD and helps designers when the object dimension and shape can be affected by limits and constraints deriving from different features and targets, such as the spatial collocation of the component and the interaction with other limiting items, for examples the material and the manufacturing issues. The concept was developed into the software SFIDA (Sailplane Fuselage Integrated Design Application) that is a first attempt to automatically manage multiple relations and optimise their combination.     

A holistic approach to achieving energy efficiency for interoperable machining systems

In the twenty-first century, the continuous demand in energy resource has put sustainability on the agenda of many businesses. This is particularly true for the manufacturing industry, where a large amount of energy is consumed to sustain daily operations. This paper studies energy-efficient computer numerical control machining systems. To achieve overall energy efficiency in machining systems, several activities are involved as in the proposed research framework of a global energy-efficient machining system (GEMS). These activities are described as modules, i.e. energy monitoring, energy analysis and optimisation, energy-based optimal control and energy-enriched database. In a GEMS, one critical issue is data interoperability. Seamless data sharing enables collaboration for improving energy efficiency. Using the EXPRESS language, energy data models are proposed for each module in the GEMS, and integrated with the existing STEP-NC (STandard for Exchange of Produce-compliant Numerical Control) standards. Two case studies are presented to demonstrate how the proposed data models may be used. One study updates an existing production file to include general energy information for auditing or reviewing purposes; the other study maintains machine tool energy profiles in a database. Many other energy-efficient activities, e.g. online energy optimisation, can be realised with the proposed data models. The present study proved that interoperable energy information can enhance the energy-efficient performance of a machining system.     

Income Growth,Urbanization, Changing Life Style and Energy Requirements in China

Abstract

This paper aims to estimate the effects of changing life style and consumption demands driven by income growth and urbanization on increase of energy requirements in China, and estimate the impacts of improvement in household consumption on mitigating energy requirements towards 2020, based on input-output analysis and scenarios simulation approach. The result shows that energy requirement per capita has increased by 159% for urban residents and 147% for rural residents from 1995 to 2004. Growth in household consumption driven by income growth and urbanization may induce a successive increase in energy requirements in future. Per capita energy requirements of urban residents will increase by 240% during 2002–2015 and 330% during 2002–2020. Urbanization might lead to 0.75 billion ton of increment of energy requirements in 2020. About 45%–48% of total energy requirements in China might be a consequence of residents’ life styles and the economic activities to support consumption demands in 2020. Under low-carbon life style scenario, per capita energy requirements of urban residents may decline to 97% in 2015 and 92% in 2020 in contrast with baseline scenario. That implies that China needs to pay a great attention to developing green low-carbon life style in order to realize mitigation target towards 2020.     

Sustainable design of sprocket using CAD and Design Optimisation

The contemporary manufacturing organisations recognise sustainability as a vital concept for survival in the competitive scenario. The modern design engineers are in need of approaches for creating environmentally friendlier products. In this context, this project reports a case study carried out in an Indian sprocket manufacturing organisation. The existing sprocket has been created using Computer Aided Design (CAD). Then, the sustainability analysis has been performed for determining the environmental impact. This is followed by the optimisation of sprocket design using Design Optimisation. The environmental impact has been measured in terms of carbon footprint, energy consumption and air/water impacts. It has been found that the optimised sprocket design possess minimal environmental impact. The results of the case study indicated that CAD and Design Optimisation could lead to the development of sustainable design with minimal impact to the environment.     

Relative Assessment of Indicators in Sustainability Enhancement (RAISE): a first approach in the manufacturing stage of products

The estimation of the sustainability performance of products requires tools to provide systematic approaches to the definition of impacts, indicators and comparative scenarios from early design stages. This paper illustrates the Relative Assessment of Indicators in Sustainability Enhancement (RAISE) methodology that is based on the measure of negative impacts generated during any product life cycle stage. This approach includes a systematic process for the definition and evaluation of indicators to compare the sustainability performance of products considering each indicator individually and using a holistic index of sustainability to entail an overall comparison between products from manufacturing scenarios. The RAISE method is developed with the aim of assessing sustainability performance of product life cycle stages and incorporating this assessment into the decision-making process when comparing different manufacturing scenarios. A guitar capo manufactured in polymeric material is used as case study to demonstrate the use of the method. In this paper, only the manufacturing stage is considered; however, the method can also be employed in other stages of the life cycle.     

Income Growth, Urbanization, Changing Life Style and Energy Requirements in China

This paper aims to estimate the effects of changing life style and consumption demands driven by income growth and urbanization on increase of energy requirements in China, and es-timate the impacts of improvement in household consumption on mitigating energy requirements towards 2020, based on input-out-put analysis and scenarios simulation approach. The result shows that energy requirement per capita has increased by 159% for urban residents and 147% for rural residents from 1995 to 2004. Growth in household consumption driven by income growth and urbanization may induce a successive increase in energy require-ments in future. Per capita energy requirements of urban residents will increase by 240% during 2002-2015 and 330% during 2002-2020. Urbanization might lead to 0.75 billion ton of increment of energy requirements in 2020. About 45%-48% of total energy requirements in China might be a consequence of residents’ life styles and the economic activities to support consumption demands in 2020. Under low-carbon life style scenario, per capita energy requirements of urban residents may decline to 97% in 2015 and 92% in 2020 in contrast with baseline scenario. That implies that China needs to pay a great attention to developing green low-carbon life style in order to realize mitigation target towards 2020.     

Comparison of different methods for uranium determination in water

Photometry, laser photometry, liquid scintillation (LSC), gamma spectrometry and alpha spectrometry were used for estimating waterborne uranium concentration. The chemical procedures applied were pre-concentration, liquid extraction, chromatographic resin extraction and precipitation. Our results show that laser photometry is an easy and accurate method capable of estimating low uranium concentrations, parts of micrograms per litre. It is not applicable for higher concentrations, difficult water matrixes and isotope determination. The classical photometry is complementary, resolving the problem related to high concentrations, practically up to 10 mg/l. Alpha and gamma spectrometry resolve the problem of precise isotope determination, but with the disadvantage of hard chemical preparation and long measurement times. An intermediate method is LSC, with the problem of isotope estimation, due to poor energy resolution.     

江苏省能源消费与经济增长耦合关系研究

能源消费与经济增长之间的关系是环境经济学研究的重要领域。以江苏省为研究区域,基于1990～2005年的年度数据,运用“脱钩”和“复钩”理论,协整分析技术和Granger因果关系检验方法,辨识和分析了的能源消费总量、电力消费和地区生产总值之间的耦合关系,实证研究表明,1990～2000年,江苏能源消费与地区生产总值处于弱“脱钩”状态,进入2000年后,二者呈现出扩张性“复钩”趋势。研究同时还发现江苏的能源消费总量与GDP之间存在长期均衡关系,表现出能源消费促进经济增长的单向格兰杰因果关系。研究结果表明了当前能源是影响江苏经济增长的关键要素,江苏在经济增长和能源利用战略等方面应当采取更加积极有效的对策。〖     

Economic growth and energy consumption in Iran: an ARDL approach including renewable and non-renewable energies

Iran experiences a high level of energy consumption which is threatening not only economically but also politically and environmentally. This study aims to estimate the relationship between the economic growth with the various kinds of energies, non-hydroelectric, renewable, non-renewable, and total energies in Iran during 1967–2012, using an autoregressive distributed lags (ARDL) model. The results show the ineffective relationship between the economic growth and energy consumption in Iran, considering non-hydroelectric energy, renewable energy, non-renewable energy, and total energy, one by one as the energy proxy. It implies the ineffectiveness of both the quantitative and qualitative deflationary policies over the energy sector. In another word, neither decreasing energy consumption nor changing energy portfolio affects the economic growth. Therefore, the policy makers are advised to formulate those policies which reduce the quantity of energy consumption or increase the segment of renewable energies in the portfolio of energy consumption because they do not lead to the considerable negative consequence on the economic growth, while they increase both the environmental quality and energy security.     

Industrial energy efficiency potentials: an assessment of three different robot concepts

The rise in energy consumption and the associated costs instigate financial concerns among industrial energy consumers. For industrial processes addressing heating and cooling as well as material transformation, a wide range of energy efficiency measures have been developed and successfully implemented. In contrast to that, most robot-based operations such as pick-and-place motions or assembly tasks still use inefficient standard concepts causing high-energy consumption and high-energy costs. Thanks to a rather low payload-to-weight ratio of new robot designs, such as parallel kinematic or hybrid robot manipulators, a high potential for energy savings is expected. This article identifies potentials for energy saving concerning industrial consumers by assessing three different robot concepts. Based on a literature review, two existing designs for robots – the conventional serial robot and the parallel kinematic robot are analysed and compared with respect to the energy utilised during a typical item placement task. Afterwards, the concept of PARAGRIP, a hybrid of the two presented robot designs is introduced and examined based on simulation regarding its energy consumption. The final results demonstrate significantly different energy consumptions between the robot concepts, identifying potential savings of about 40% in a selected industrial application scenario.     

Environmental impact of two electrical products with reference to the energy-using products directive

High energy consumption is one of the major factors that contributes to global warming. Connected to this, a directive has been approved by the European Union for establishing a legal framework to govern eco-design of energy-using products. This technical note reveals life cycle analysis of two electrical products, which rely on the same rechargeable battery system (i.e. the same energy source) for operations, with respect to the requirements of the aforementioned directive. Results concur with the argument that energy consumption of this sort of product plays a dominant role in terms of a variety of environmental impacts (like emission to air). Based on the results of this study, eco-design alternatives can be derived accordingly so that energy consumption and the existing solution can be benchmarked, as required by the directive.     

城镇化对工业能源消费的门槛效应研究——以长江经济带省份为例

高效能源利用是推动工业发展,进而促使城镇格局演化的重要催化剂,同时城镇化的高速发展对工业能源的消费结构和利用效率提出了进一步的要求,这必将影响到低碳城市建设和环境保护等生态责任目标的实现。选取2003—2012年长江经济带11个省份(直辖市)的相关数据,运用门槛模型对城镇化率、城镇居民人均总收入、能源工业投资、工业总产值、城市人口密度、产业结构等影响工业能源消费的因素进行分析,重点研究城镇化率和工业能源消费的非线性关系和相应的地区差异。结果表明:(1)长江经济带城镇化发展存在着明显的地区差异,上海、浙江等东部地区城镇化发展速度和水平明显优于云南、贵州等中西部地区。云南和贵州2012年的城镇化率远远低于2003年上海、浙江的城镇化率,显示出长江上游和下游之间存在着巨大的发展水平差距。(2)城镇化对工业能源消费存在显著的门槛效应,以城镇化率为门槛变量,存在两个结构变化点,分别为36.9%和48.3%。(3)在第一个门槛点前,城镇化对工业能源消费起抑制作用,前期城镇化的发展导致资源和人口的集聚效应明显,资源的利用效率和配置效率得到提升,从而抑制工业能源消费。在越过第二个门槛点后,城镇化对工业能源消费起正向作用,此时工业的发展和生活消费水准的提升对能源消费提出了更多的要求。最后为促进长江经济带城镇化和工业低碳化的协调发展,提出以下建议:加快长江经济带沿线各省份联动发展,缩小城镇化发展差异;针对城镇化率和工业能源消费的非线性关系,采取相应的措施引导和控制工业能源消费的变化趋势;协调城镇化进程和地区工业能源消耗,促进城镇化的健康发展。     

基于情景分析法的中国馆碳减排效益评估

建筑部门的低碳发展已成为推进我国低碳经济至关重要的一个组成部分,因此正确客观地评价建筑的低碳水平具有重要的指导意义。本文以2010年上海世博会中国馆为研究对象,采用碳排放情景分析法,针对中国馆的基准建筑与实际建筑,计算其世博结束后正常运行条件下的碳排放水平,评估中国馆实际建筑的碳减排效益。使用建筑能耗模拟软件DesignBuilder对建筑全年能源消耗水平进行了模拟,并通过相应能源品种的碳排放因子分别计算了实际建筑和基准建筑的碳排放水平;同时应用全生命周期方法(LCA)分析了中国馆实际建筑应用太阳能光伏、LED照明技术相比于基准建筑所带来的减排效益。结果表明:世博结束后正常运行条件下,中国馆实际建筑年碳排放量为18 969 t CO2e,基准建筑年碳排放量为25 770 t CO2e,因此,相比基准建筑,中国馆实际建筑一年减排6 801 t CO2e,年碳减排率为26.4%;减排效益主要由节能设计及绿色技术贡献,分别占96.3%和3.7%。本文通过综合评估中国馆的碳减排效益,以期为我国公共建筑低碳工作的开展进行有益的探索。     

Climate change impacts,vulnerability and adaptive capacity of the electrical energy sector in Cyprus

The purpose of this study was to investigate the climate change impacts, vulnerability and adaptive capacity of the electrical energy sector in Cyprus. Spatial vulnerability of the island was assessed using the degree-day indicator to investigate heating and cooling demands in the near future using daily temperature projections from regional climate models (RCMs). Using daily electrical energy consumption data for the present climate, an impact model linking consumption and temperature was constructed and this relationship was projected to the future climate using the data from the RCMs and assuming the same technology use. Our impact model results showed that for the period between November and April (‘cold period’), a decreasing trend in electrical energy consumption is evident due to warmer conditions in the near future, while for the period between May and October (‘warm period’), an increasing trend in electricity consumption is evident as warmer conditions dominate by 2050. Regarding the spatial vulnerability assessment, the cooling degree-day indicator testified that major increases in cooling demand, between 100 and 200 degree-days, are expected in inland and southern regions during the summer in the near future. In addition, increases of about 20–50 degree-days are anticipated during autumn. Conversely, energy demand for heating is projected to decrease during spring and winter, especially in the higher elevation parts of the island. More precisely, reductions of about 30–75 degree-days are projected during spring, while greater reductions of about 60–90 degree-days are expected during winter in heating demand, especially for in the near future. The ability of the energy sector to adapt and follow these changes was deemed to be satisfactory reducing the overall vulnerability of the sector to future climate change.     

天津市工业行业全要素能源效率变动的影响因素分析

天津市作为一个典型的工业城市,工业行业能源效率水平决定了其能否完成"十二五"期间单位生产总值能耗比"十一五"末下降18%的国家节能降耗考核目标。正确把握影响工业行业能源效率变动的因素是天津市寻求节能降耗途径的关键。本文以1998-2008年天津市工业行业的能源消耗面板数据为样本,通过引入非参数Malmquist生产率指数,从技术进步、纯技术效率和规模效率指数角度分析天津市工业行业全要素能源效率变化情况,并运用Tobit模型估计工业化水平、工业内部结构、技术进步、产权结构、政府影响力、进出口贸易和能源消费结构等要素对工业行业全要素能源效率变化的影响程度。研究表明:1998-2008年期间,天津市工业行业间的能源效率差异显著,整体全要素能源效率不断提高,技术进步是其提高的主要原因,但技术效率表现为负增长;工业化水平、技术进步、进出口贸易和能源消费结构的调整对工业行业能源效率的提升具有不同程度的促进作用,但重工业和国有经济比重的增加及政府对能源市场的干预对能源效率的提升起负向作用。因此,天津市工业行业能源效率的进一步提高,需要大力开发、推广和使用先进技术及设备,加强对外开放力度,降低重工业和国有经济比重,充分发挥市场调节能源配置的优势。