Energy consumption model and energy efficiency evaluation for CNC continuous generating grinding machine tools

Abstract

Machine tool, which is the basis energy consumed device in manufacturing system, its energy consumption model and energy efficiency evaluation are the prerequisites for energy saving in manufacturing. Considering the multi-energy-sources features，analysed the mathematical model of a CNC continuous generating grinding machine tool from the view of energy constitute. The energy sources of a CNC continuous generating grinding machine tool are classified into gear grinding system, grinding wheel dressing system and auxiliary system. Based on the power balance equations of energy flow, the energy flow system of a CNC continuous generating grinding machine tool is established. And then the energy consumption mathematical model of a CNC continuous generating grinding machine tool is set up by combining the power balance equations with the operating features of three kinds of energy sources. The case study shows that the proposed energy consumption model can provide fundamental support for energy consumption forecasting, energy efficiency analysis and energy-saving optimisation during the machine tool operation process.     

A methodology for electricity monitoring and targeting (M&T) in an Irish precision engineering SME

Abstract

Energy management in small to medium enterprises (SMEs) remains undeveloped due to competing priorities and a lack of specialist knowledge. However considerable savings can be demonstrated where companies take the time to investigate their energy use. Savings of over 20% can be achieved through changes to operational and behavioural practice. Additional benefits, such as improved production tracking and improved maintenance, can been seen which add to the value in undertaking an energy monitoring and targeting (M&T) plan. The method described involves the application of a series of ‘virtuous’ cycles of engagement and energy savings that can be applied from the highest factory level right down to a specific machine. The analysis of overall energy use from utility bills and the visualisation of typical machine power profiles aid in understanding the drivers of energy consumption and in engaging management in energy efficiency. The monitoring of specific machines in production highlights the significant consumption of electricity during non-productive times. The development of energy performance indicators is described for product variations which can be useful in tendering for business and selecting optimum production pathways. The approach is illustrated with data from a case study of a precision engineering SME based in Limerick, Ireland.     

Renewable energy potential in India and future agenda of research

ABSTRACT

Demand of electrical energy is exponentially increasing causing environmental problems due to extensive use of fossil fuels. Hence, research has been promoted in renewable energy technologies to mitigate environmental pollution. Indian subcontinent is rich in renewable energy sources (RES). This paper describes potential of RES and region-wise installed capacity in India. Estimated potential of RES is 57 GW which is targeted to be 175 GW by 2022. A logical framework for our future research work has been presented. This includes performance optimisation of solar pumping system and reliability assessments of the designed system using reliability indices.

Abbreviation: RES: Renewable energy resources; SHP: small hydro plants; GOI: Government of India; MNRE: Ministry of New and Renewable Energy; LHP: large hydropower; BCM: billion cubic metres; PEC: per-capita energy consumption; JNNSM: Jawaharlal Nehru National Solar Mission; DNI: direct normal irradiance; SPV: solar photovoltaic; UMPP: ultra mega green solar power project; GIS: geographic information systems; WMS: wind monitoring stations; MPWL: Madhya Pradesh windfarms Ltd.; MIB: mat river basin; SWAT: Soil and Water Assessment Tool; ROR: run of river; SMS: short message service; CDM: clean development mechanism; NIOT: national institute of ocean technology; LOLP: loss of load probability; CSO: Central Statistics Office; CEA: Central Electricity Authority; TERI: The Energy and Resources Institute; WPI: Wind Power India; IEA: International Energy Agency; EAI: Energy Alternatives India; BKP: Biomass Knowledge Portal; IRENA: International Renewable Energy Agency; GAIN: Global Agricultural Information Network; NITI: National Institution for Transforming India; NIWE: National Institute of Wind Energy; UP: Uttar Pradesh; J&K: Jammu and Kashmir; HP: Himachal Pradesh; NR: northern region; MP: Madhya Pradesh; WR: western region; TN: Tamil Nadu; AP: Andhra Pradesh; SR: southern region; ER: eastern region; NER: north eastern region; A&N: Andaman & Nicobar     

美国居民生活用能状况与趋势:30年微观调查数据分析

随着居民部门用能快速增长,各国都在致力于观察本国居民能源消费特征以减少碳排放,特别是发达国家。本文应用近30年的微观调查数据分析美国居民能源消费现状和趋势,为发展中国家提供一些借鉴意义。从总量上看,伴随着人口、家庭数量和建筑面积的上升,能源消费总量变化较小,趋于稳定;人均用能则呈下降趋势。从用能结构来看,以天然气和电力为主,2009年分别占比44%和41%;近30年来天然气占比小幅下降,电力占比上升明显;完善的天然气设施和电力服务体系使得能源可获得性高。从用途分类来看,取暖和家电占绝大比例,2009年分别占比41%和35%;取暖用能近30年来出现平缓下降趋势,燃料来源70%是天然气;家电设备用能占比明显上升,增长近1倍;制冷占比较小,近年出现小幅上升;热水用能则比较稳定。家庭炊事燃料以电力和天然气为主,2009年分别占比60%和34%。近30年,家用电器保有量和能源效率有显著提高。建筑用能方面,美国房屋服务时间长,后期建筑房屋在保温性能方面高于早期房屋,单位面积耗能下降。美国居民享受着较高水平的能源服务,能源消费总量在近30年没有明显变化,这和能源效率的提高有着密切关系;如完善的"能源之星"项目是一个强有力的措施,以及完善的能源统计制度为能源分析提供了有力的数据支撑。相比,中国存在居民炊事用能固体燃料占比较高、建筑服务周期短、建筑材料耗能比重大等问题。建议中国政府进一步完善能源统计制度、推行农村能源扶持项目和能源标识、加强建筑规划、落实建筑能耗标准。     

自主研发、技术引进与能源消耗强度——基于中国工业行业的实证分析

本文运用1998-2007年中国工业32个行业面板数据,将工业各行业研发总支出划分为自主研发、国外技术引进和国内技术转移三个部分,在估算自主研发存量和技术引进存量的基础上,研究了自主研发、技术引进对工业能源消耗强度的影响,并考察了能源相对价格、FDI的进入程度以及工业内部行业结构等因素.研究表明,自主研发和国外技术引进对能源强度的影响存在行业差异.自主研发对全工业行业和高能源强度行业的能源强度有显著负效应,对低能源强度行业的影响不显著;国内技术转移对全工业行业和低能源强度行业的能源强度有显著负的影响,对高能源强度行业的影响不显著;国外技术引进在所有样本中对能源强度的影响均不显著.研究还发现,在低能源强度行业中,自主研发并没有与国外技术引进互为补充共同促进能源强度的下降;在高、低能源强度行业样本中,自主研发没有与国内技术转移形成互补优势,有助于能源强度的下降.     

Which crop production system is more efficient in energy use: wheat or barley?

Efficient use of energy helps to achieve increased production and productivity and contributes to the economy, profitability, and competitiveness of agricultural sustainability of rural communities. Evaluation of wheat and barley production systems in view of energy balance was conducted in Khorasan Razavi Province, Iran. Data were collected by using a face-to-face questionnaire from wheat and barley fields in 2011. Results revealed that total energy input for wheat was 51,040 MJ ha^?1 and for barley 44,866; in wheat and barley systems, renewable energy was consumed by 25.43 and 23.53 %, while non-renewable energy was consumed by 74.57 and 76.47 %, respectively. Energy use efficiency, energy productivity, and net energy were 1.7 kg MJ^?1, 0.088 kg MJ^?1, and 35,987 MJ ha^?1 in wheat system and 1.83 kg MJ^?1, 0.092 kg MJ^?1, and 33,833 MJ ha^?1 in barley system, respectively. Energy intensiveness in wheat fields (61.84 MJ $^?1) was higher than in barley fields (58.71 MJ $^?1). Also, benefit-to-cost ratio in wheat system (1.59) was higher than in barley system (1.35). In general, production in barley fields was more sustainable than wheat production because, in view of ecological indices such as amount of energy use and renewable energy consumption, it was more environment-friendly production.     

Technological Progress,Structural Change and China’s Energy Efficiency

Abstract

China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption per unit of GDP, however, experienced continuous decrease. Theoretically, the change of energy efficiency can be attributed to industry structural change and technological change. In order to explain the transformation of Chinese energy efficiency, we adopt logarithmic mean Divisia index techniques to decompose changes in energy intensity in the period of 1994–2005. We find that technological change is the dominant contributor in the decline of energy intensity, but the contribution has declined since 2001. The change in industry structure has decreased the energy intensity before 1998, but raised the intensity after 1998. Decomposed technological effects for all sectors indicate that technological progresses in high energy consuming industries such as raw chemical materials and chemical products, smelting and pressing of ferrous metals, manufacture of non-metallic mineral products and household contribute are the principal drivers of China’s declining energy intensity.     

江苏、安徽能源强度比较分析与启示

能源在社会经济发展中具有重要作用。随着能源消耗量剧增，能源供需矛盾、环境问题日益突出，研究区域能源强度变化具有重要的现实意义。采用Laspeyres因素分解法，定量分析江苏省和安徽省的产业结构和产业效率对能源强度的影响。研究发现：（1）安徽省的能源强度高于江苏省的能源强度，不过差距在逐渐变小，利用重标极差法预测未来两省的能源强度会逐渐趋同；（2）江苏省的产业结构发展有减小能源强度的趋势，不过作用过程有波动；产业效率有利于降低能源强度；（3）安徽省的产业结构有助于增加能源强度，作用趋势还在增大，产业效率有利于降低能源强度，降低作用大于江苏省。因此本文提出目前同样的投入应该偏向欠发达地区或能源强度较高地区，这有利于快速取得降低能源强度的成效.     

Research on Energy Consumption Evaluation Combined with Endogenous Pollutants of China Based on Entropy-Topsis

Abstract

The traditional evaluation of energy consumption mostly introduces pollutants as a negative economic output into evaluating model, ignoring the configuration relationship among the energy input, pollutants as well as economic output. This paper considers the overall process of energy consumption and constructs an evaluation indication system of energy consumption level combined with endogenous pollutants based on entropytopsis method, then makes empirical research. The results show that China’s energy consumption level presents a fluctuant rise in the premise of emission. Energy consumption level depends on the relationship among energy input, pollutants and economic output. The raise of energy consumption level should not increase economic output and reduce pollutant emission at the expense of environment. Finally, the whole paper puts forward the countermeasures to improve the overall level of energy consumption.     

中国的能源工业及其污染防治

能源工业是我国的基础工业,也是经济发展的战略重点,同时又是重要的污染源。由于我国能源以煤炭为主,所以能源工业的污染主要是煤的开采利用带来的。因此,应当把煤炭开采、利用造成的污染作为防治重点,从节能降耗、提高燃烧效率、改善能源结构、消除煤炭开采、利用中产生的污染等几个方面入手,从根本上解决能源工业的环境问题,努力处理好经济发展和环境保护的关系,实现能源与环境的协调发展和经济的持续增长。     

Spatial and temporal variation of energy carbon emissions in Yantai from 2001 to 2011

In order to understand the characteristics of spatial and temporal variation, as well as provide effective ideas on carbon emissions and regulatory policy in Yantai, this article analyzed spatial and temporal variation of carbon emissions in Yantai based on energy consumption statistics for a variety of energy sorts together with industrial sectors from 2001 to 2011. The results were as following: First of all, Yantai’s carbon emissions grew by an average of 5.5% per year during the last 10 years, and there was a peak of 10.48 million carbon in the year of 2011. Second, compared with the gross domestic product (GDP) growth rate, the figures for energy carbon emissions growth rate were smaller; however the problem of carbon emissions were still more obvious. Furthermore, carbon emissions in Yantai increased rapidly before 2008; while after 2008, it increased more slowly and gradually become stable. Third, the energy consumption was different among regions in Yantai. For instance, the energy consumption in Longkou city was the largest, which occupied 50% of the total carbon emissions in Yantai; and the energy consumption in Chang Island was generally less than 1% of the Longkou consumption. Finally, there were relative close relationships among the spatial difference of carbon emissions, regional resources endowment, economic development, industrial structure, and energy efficiency.     

Energy analysis of algae-to-biofuel production chains integrated with a combined heat and power plant

ABSTRACT

This study examines the energy and mass balances of algae cultivation and different post-processing pathways. Flue gases and excess heat from a combined heat and power (CHP) plant are used in algae cultivation, with nutrients from municipal wastewater. In the studied pathways, algae are cultivated in open ponds and photobioreactors with or without artificial lighting. Algal mass is used for methane, biodiesel or ethanol production, or it is combusted in a boiler. Results show that in most process pathways energy output exceeds the energy consumption in processing, and the energy returns are approximately twice as large as the electricity input. A large fraction of input energy is low-temperature heat, while the products have a higher value. Energy outputs from different pathways are similar, but heat and electricity consumption in processing vary significantly. Supercritical water gasification pathway is identified as a possible future option, whereas lipid extraction pathways are suggested to be the most likely candidates for industrial scale operations.     

Prediction of primary energy demand in China based on AGAEDE optimal model

In this article,we present an application of Adaptive Genetic Algorithm Energy Demand Estimation(AGAEDE) optimal model to improve the efficiency of energy demand prediction.The coefficients of the two forms of the model(both linear and quadratic) are optimized by AGA using factors,such as GDP,population,urbanization rate,and RD inputs together with energy consumption structure,that affect demand.Since the spurious regression phenomenon occurs for a wide range of time series analysis in econometrics,we also discuss this problem for the current artificial intelligence model.The simulation results show that the proposed model is more accurate and reliable compared with other existing methods and the China's energy demand will be 5.23 billion TCE in 2020 according to the average results of the AGAEDE optimal model.Further discussion illustrates that there will be great pressure for China to fulfill the planned goal of controlling energy demand set in the National Energy Demand Project(2014—2020).     

Economic feasibility of autonomous hybrid wind–diesel power systems for residential loads in hot regions: a step to mitigate the implications of fossil fuel depletion

Today, energy occupies a pivotal position around which all socio-economic activities revolve. No energy means no life, and supply of energy in a cheap, plentiful, long-sustainable and environmentally safe form is a boon for everyone. In the light of rising cost of oil and fears of its exhaustion coupled with increased pollution, the governments worldwide are deliberating and making huge strides to promote renewable energy sources such as wind. Integration of wind machines with the diesel plants is pursued widely to reduce dependence on fossil-fuel-produced energy and to reduce the release of carbon gases that cause global climate change. The literature indicates that commercial/residential buildings in the Kingdom of Saudi Arabia (KSA) consume an estimated 10–40% of the total electric energy generated. The aim of this study is to analyse wind-speed data of Dhahran (East-Coast, KSA) to assess the economic feasibility of utilising autonomous hybrid wind–diesel power systems to meet the electrical load of 100 typical residential buildings (with annual electrical energy demand of 3512 MWh). The monthly average wind speeds range from 3.3 to 5.6 m/s. The hybrid systems simulated consist of different combinations of 600 kW commercial wind machines supplemented with diesel generators. The National Renewable Energy Laboratory's hybrid optimisation model for electric renewables software was employed to perform the techno-economic analysis.

The simulation results indicate that for a hybrid system comprising 600 kW wind capacity together with a 1.0 MW diesel system (two 500 kW units), the wind penetration (at 50 m hub-height, with 0% annual capacity shortage) is 26%. The cost of generating energy (COE, $/kWh) from this hybrid wind–diesel system was found to be 0.070 $/kWh (assuming diesel fuel price of 0.1 $/l). The study exhibits that for a given hybrid configuration, the number of operational hours of diesel generator sets (gensets) decreases with an increase in the wind-farm capacity. Concurrently, emphasis has also been placed on wind penetration, un-met load, effect of hub-height on energy production and COE, excess electricity generation, percentage fuel savings and reduction in carbon emissions (relative to diesel-only situation) of different hybrid systems, cost breakdown of wind–diesel systems, COE of different hybrid systems, etc.     

NEWS

Abstract

Co-integration theory has been employed in this paper and Granger causes are found between urbanization rate and GDP, between capital stock and GDP. Scenario analysis of GDP is performed using the GDP model established in the paper. The energy consumptions in Germany, Japan and other developed countries are analyzed and compared with the energy consumption in China. Environmental friendly scenario of energy demand and CO₂ emissions for sustainable China has been formed based on the results of comparison. Under environmental friendly scenario, the primary energy consumption will be 4.31 billion ton coal equivalence (tce) and CO₂ emissions will be 1.854 billion t-c in 2050; energy per capital will be 3.06 tce that is 1.8 times of energy consumed in 2005 in China and 51% of consumed energy per capital in Japan in 2003. In 2050, the energy requirement of unit GDP will be 20% lower than that of Germany in 2003, but will be still 37% higher than that in Japan in 2003. It is certain that to fulfill the environmental friendly Scenario of energy demand and CO₂ emissions is a difficult task and it needs long term efforts of the whole society, not only in production sectors but also in service and household sectors.     

中国碳排放的因素分解模型及实证分析:1995-2004

能源消费是碳排放的主要来源。随着中国经济的快速发展,能源消费的急剧增长以及以煤为主的能源结构在短期内很难改变,因此,碳排放不可避免地会出现一定幅度的增加。本文基于碳排放量的基本等式,采用对数平均权重Divisia分解法（Logarithmic mean weight Divisia method,LMD）,建立中国人均碳排放的因素分解模型,定量分析了1995-2004年间,能源结构、能源效率和经济发展等因素的变化对中国人均碳排放的影响,结果显示经济发展对拉动中国人均碳排放的贡献率呈指数增长,而能源效率和能源结构对抑制中国人均碳排放的贡献率都呈倒“U”。这说明能源效率对抑制中国碳排放的作用在减弱,以煤为主的能源结构未发生根本性变化,能源效率和能源结构的抑制作用难以抵销由经济发展拉动的中国碳排放量增长。     

Environmentally compatible energy resource production—consumption pattern (case study: Iran)

Like all rapidly developing countries, the government of Iran (GOI) has to integrate environment priorities into its energy sector. In order to integrate environmental concerns into energy sector, an Energy-Environment Review (EER) may be considered as the mainstreaming tool capable of examining the interface between energy and the environment. The results of the EER should be interpreted, in the light of the objective of the 4th Five Year Development Plan in Iran, to achieve fast and sustainable growth and accelerate the transition to a market economy. In particular, the suggested actions will promote economic efficiency use of energy resources through a proper allocation of scarce resources, including environmental resources, so as to achieve economic efficiency and environmental and social protection. This paper comprises: (A) an analysis of the current situation with regards to energy production and consumption; (B) an evaluation of the growth prospects with regard to energy production and consumption; (C) the identification of environmental issues induced by the generation and use of energy and estimation of the associated costs of damages; (D) the evaluation of the extent of contribution to the climate-change phenomenon through emission of greenhouse gases; (E) the evaluation of the proposed mitigation measures for the previously identified environmental problems; and (F) conclusions and recommendations. The EER-Iran assessed the total health damage from air pollution in 2001 at about 56  ×  10¹² Rials (US $ seven billion); equivalent to 8.4% of nominal GDP. In the absence of the price reform and control policies, the EER-Iran estimated that the damage in Iran in the money of 2001, will grow to 155  ×  10¹² Rials (US $ nine billion) by 2019. This is equivalent to 10.9% of nominal GDP, i.e., a large percentage of a larger GDP. Of this total, 107  ×  10¹² Rials (US $ 8.4 billion) come from transport sector. The damage cost to the global environment from the flaring of natural gas, assessed on the basis of a carbon price of US $ 10/ton CO₂, is found to be approximately US $ 600 million per year. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Sustainable gas turbine power generation by adopting green control technologies

Performance analysis of a gas turbine with two configurations (a parallel and series free turbine) is presented and analysed. A simple configuration is analysed here for comparison. The performance parameters are work output, specific fuel consumption (SFC) and efficiency. Off-design characteristics are based on two methods of control, the first (A) is fixing the compressor–turbine inlet temperature (TIT) and varying the power TIT, whereas the second (B) method is by varying the two turbine-inlet temperatures while keeping them equal. Conclusively the series configuration has higher work output (11%), whereas the parallel arrangement has higher efficiency and lower SFC (9%). Hence, as a compromise, it is more efficient and work-productive to use method A (TIT = const.) to control both series and parallel arrangements than using method B (TIT = T₅).     

中国农村能源正义的法律实现

为了厘清中国能源正义的现况,为《能源法》的制定提供直接参考,本文选择中国农村能源正义作为具体的研究对象,主要采用规范分析的研究方法,从能源正义和农村能源正义的概念界定入手,描述了中国农村能源不正义的事实现况和法律现况,指出了中国农村环境正义法律实现的路径,并阐释了法律实现的关键。本文认为,农村能源正义是指,能源的所有方、供给服务方、消费方等主体不因其农民的身份性质、农村的地域分布和农业的禀赋强弱等因素,而应在能源的勘探开发、加工转换、仓储运输、供给服务等领域享有平等的对待和实质的参与;农村能源不正义的事实现况主要表现为农村能源并未全面体现能源的自然、经济、安全和生态等多维价值,而其法律现况则主要表现为现有的能源立法并未对农村能源在分配、程序、矫正和社会正义上做系统的表达。本文指出,中国农村能源正义法律实现的路径,其逻辑起点在于保障农民的能源权,应首先从法律上正面规定公民的能源权,进而采用《能源法》的集中表达与相关法律部门的分散表达相结合的具体方式和步骤。本文建议,中国农村能源正义法律实现的关键是科学制定《能源法》,首先要明确其核心地位,处理好与《农业法》等法律部门之间的关系;其次要在总则中,重述立法目的、规定公民能源权、完善能源普遍服务;最后在《能源法》的分则中专设"农村能源"的章节,整合现有的《能源法(征求意见稿)》的内容,并从原则、规划、保障、生态化、公众参与、授权、救济、法律责任等方面进行优化。     

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.