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.     

Reducing carbon emissions in Portugal: the relative roles of fossil fuel prices,energy efficiency,and carbon taxation

We assess the role of fossil fuel prices, energy efficiency, and carbon taxation in achieving climate policy goals using a dynamic general-equilibrium model of the Portuguese economy. Given the forecasts for international fossil fuel prices, improving energy efficiency and implementing a new carbon tax have significantly different economic and budgetary effects. Greater energy efficiency reduces emissions and has a positive economic effect, but increases public and foreign debt. A carbon tax reduces emissions at a cost for the economy, but leads to positive effects on public and foreign debt. Thus, it is important to pursue both strategies. We estimate that under the reference-price scenario, a steady energy efficiency gain of 2%–2.5% per year and a carbon tax of at least 35 € per tCO₂ are needed to achieve the stated goal of reducing carbon dioxide emissions by 2030 by an amount equivalent to 40% of the emissions in 1990. These views were fully integrated in a proposal presented by the Commission for Environmental Tax Reform to the Portuguese Government in September 2014, and then discussed in Parliament in November 2014, before enacting a new carbon tax on 1 January 2015.     

SSI效应对粘弹性阻尼结构减震效果的影响分析

本文以一单跨7层框架结构为研究对象,对不同场地和地震波输入条件下的粘弹性阻尼结构进行了二维有限元时程分析,探讨了SSI(土-结构动力相互作用)效应对粘弹性阻尼结构减震效果的影响。分析结果表明:①在硬土和稍硬土地基条件下,SSI效应明显降低了结构的楼层位移峰值,若在抗震设计中对客观存在的SSI效应加以考虑,设置较少数量的阻尼器(与刚性地基假定条件下确定的阻尼器数量相比)就能使结构的实际地震位移反应满足基于刚性地基假定的地震位移控制目标;②粘弹性阻尼结构的减震效果与场地条件、输入地震动特性密切相关;③与刚性地基相比,SSI效应使粘弹性阻尼结构的减震效果明显降低,且地基越软,降低幅度越大。因此,在实际的工程设计中,应当充分考虑SSI效应,对粘弹性阻尼结构的减震控制效果进行合理的评价,并针对不同的场地条件选用合适的阻尼器类型和性能参数,才有可能达到预期的减震控制效果。     

Effects of low concentrations of the phenylurea herbicide diuron on biofilm algae and bacteria

A system of recirculating channels was used in this study to examine the long-term effects (29 d) of environmentally realistic concentrations of the herbicide diuron (from 0.07 to 7 μg L⁻¹) on biofilm communities. The autotrophic activity of biofilms was affected by this herbicide, as reflected by a marked decrease in the photosynthetic efficiency. Diuron exposure also increased chlorophyll-a content and reduced the biovolume of diatom taxa at low concentrations. The effects on bacteria were also remarkable. Bacterial abundance was reduced after a week of exposure to the herbicide at a range of concentrations. Effects were on the number of live bacteria and on the increase in the leucine-aminopeptidase activity. It is suggested that inputs of herbicides to the river ecosystem at low concentrations may cause a chain of effects in the biofilm, which include inhibitory effects on algae but also indirect effects on the relationships between biofilm components.     

Effects of ozone on inter- and intra-species competition and photosynthesis in mesocosms of Lolium perenne and Trifolium repens

Trifolium repens and Lolium perenne were exposed as both monocultures and two-species mixtures to an episodic rural ozone regime in large, well-watered containers within solardomes for 12 weeks. There were reductions in biomass for T. repens, but not L. perenne, and the proportion of T. repens decreased in ozone-exposed mixtures compared to the control. In addition, leaf biomass of T. repens was maintained at the expense of biomass partitioning to the stolons. The decreased growth corresponded with decreased photosynthetic capacity for T. repens, however, by the end of the exposure there was also decreased photosynthetic capacity of L. perenne, a species previously considered insensitive to ozone. The observed decreases in photosynthetic efficiency and capacity in elevated ozone indicate that the ability of such ubiquitous vegetation to act as a sink for atmospheric carbon may be reduced in future climates.     

Elasticity Ratio of Resource Consumption and the Resource Consumption

Today the resources are becoming scarcer, which should not be regarded as unexhausted any more. Correspondingly, the production would be constrained by the scarcity of resources clearly. Then the economic researchers would pay much more attention to reducing the consumption of natural resources in the future. Therefore this paper brings foreword the conception of elasticity ratio of resource consumption based on the concept of elasticity and analyzes the relationship between the parameters. For the certain relationships between the elasticity ratio of resource consumption and resource consumption, this paper will try to reveal, to keep economy growing while resource consumption reducing, what conditions should be met as to the relationships among resource productivity, its growth rate, energy saving efficiency, economic growth rate and elasticity ratio of resource consumption. This paper proves the relationship between the China＇s energy consumption and economy growth using statistic data from 1978 to 2003.     

基于物质流分析的江苏省区域生态效率评价

物质流分析被认为是适用于生态效率评价的重要工具和方法之一,但应用于区域生态效率评价的研究尚较少。根据生态效率理论、物质流分析理论与方法,建立了基于物质流账户的3个层面的区域生态效率评价指标：区域直接生态效率、区域总生态效率、整体生态效率。以江苏省为例,全面评价了 1995~2005年江苏省不同层面的生态效率,结果表明：（1）江苏省区域直接生态效率远高于我国同期水平。区域总生态效率和整体生态效率相对较低,分别仅为区域直接生态效率 15%~22%和 7%~8%左右;（2）1995~2005年,区域直接生态效率呈先上升后下降趋势,原因在于物质生产率未有显著提高以及近年来重工业在产业结构中比重的增加;（3）整体生态效率的变化趋势与区域直接生态效率类似,原因主要是近年江苏省对区外物质和资源的进口量显著增加;（4）区域总生态效率则表现为先快速上升后缓慢上升的趋势。在对研究结果及成因进行分析和讨论的基础上,提出了提高区域生态效率的建议.     

长江流域能源利用效率研究

考察长江流域四川、重庆、湖南、湖北 、江西、安徽、浙江、江苏、上海七省二市能源利用效率,比较分析其差异以及原因,寻求提高能源利用效率的途径。首先定义能源利用效率为能源通过要素优化配置产生的技术效率,然后利用数据包络DEA和全要素效率SFA方法进行测度,最后通过比较拉氏指数与迪氏指数的优劣,采用迪氏指数法对能源利用效率影响因素进行分解。计算出七省二市及六部门1997~2006年GDP能耗、能源技术效率和能源利用效率,并分析了结构调整、技术进步和制度进化对能源效率的影响程度。研究表明：（1）结构调整是提高能源利用效率的有力措施;（2）技术进步和制度进化是提高能源利用效率的关键;（3）能源利用效率研究方法应尽量统一并不断改进.     

颗粒层非稳态过滤捕集效率的研究

为计算颗粒层非稳态过滤效率,通过改进经典过滤理论模型,考虑颗粒在过滤介质中的沉积,理论推导得出非稳态过滤效率的计算公式,而经典颗粒层过滤效率计算公式仅为此计算公式的特例。因为理论计算公式是隐函数,不便于工程实际应用,所以,在常温条件下,对非稳态过滤时的过滤时间、过滤风速、过滤层厚度、粉尘浓度和颗粒层滤料均粒径等五个因素进行了正交实验研究。采用多元回归的方法得出各影响因素与过滤效率呈显性关系的效率关联计算公式,其计算结果与实验测试结果基本吻合。