Public energy performance policy and the effect on diffusion of solar thermal systems in buildings: A Dutch experience

Energy performance policy is an important element in the European Energy Performance of Buildings Directive (Directive 2002/91/EC—in short: EPBD, published 4 January 2003), which the European Commission is now urging all European member states to introduce for the building sector by 2006. One of the expected benefits of energy performance policy is that it can help to introduce innovations such as solar thermal systems. However, few studies have analysed this so far. This paper describes the extent to which the penetration of solar thermal systems in the residential building sector is directly related to energy performance policy in the Netherlands. The concept of energy performance policy is explained and the effects of using energy performance policy for several years in the Netherlands are described, through the results of an empirical study. Statistical analysis appears to show no association between Dutch energy performance policy and the application of solar thermal systems in the domestic sector.     

上海市合同能源管理项目实施信息化管理的经验与启示

节能服务公司和合同能源管理项目近年来在我国发展迅速,为促进合同能源管理机制的进一步完善,建立一个科学、适用的管理平台,实现合同能源项目的报备、国家相关优惠补助政策和合同能源管理知识的宣传等等,都是很必要的。上海市合同能源指导委员会办公室通过管理信息系统,配合政府主管部门开展节能管理和监察工作,有效地促进了合同能源管理项目的信息共享,优化了资金审批流程,并为合同能源管理统计和分析工作提供了便利。     

宝钢合同能源管理的应用潜力与实践

宝钢作为大型高耗能国有企业,肩负着节能减排的重任。自建厂30多年来,通过技改、科研、维修工程等多种渠道在节能减排方面取得了显著成效。合同能源管理这一新的节能机制,作为公司现有节能项目实施渠道的扩展,为节能减排工作注入新的活力与潜力。文章在概述宝钢合同能源管理工作基础上,重点对宝钢开展过程中遇到的问题进行分析总结,并对其它钢铁企业合同能源管理工作提出建议。     

Does the production of Belgian bioethanol fit with European requirements on GHG emissions? Case of wheat

This paper undertakes an environmental evaluation of bioethanol production, using wheat cultivated in Belgium. Cultivation steps are modelled using Belgian specific data. Wheat transformation in ethanol relies on industrial data. GHG emissions of the whole life cycle are calculated and compared with the default values given by the European Renewable Energy Directive. Belgian wheat bioethanol achieves a 5% higher GHG reduction than the one mentioned in the European directive but impact repartition is different with a higher importance of cultivation step in our case. Belgian wheat bioethanol complies with the current sustainability criteria but is also able to conform to further ones. Sensitivity analyses are performed on the importance of N fertilizers and associated emissions known as main important parameters. These analyses reveal non negligible variations and then a range of available GHG reduction when using wheat bioethanol.     

万物互联视角下的能源物联网：现状、技术和案例分析

目的 万物互联(IoE)时代酝酿着的新一代物联网（IoT）的发展,正在通过选择和组合其中的新信息、新功能、新应用,来实现其多样化发展。基于物联网技术的能源物联网,将物理事物之间的信息交换和能源交换,在同一张动态网络中连接起来。能源物联网催生着新的服务模式和能源的组织、交换、管理方式;它不仅涵盖能源即服务（Energy-as-a-service）和产销者（Prosumer）等新概念,还引领智慧建筑、智能抄表、智慧电网、分布式能源、虚拟电厂等创新应用。 方法 文章分析了能源物联网的现状,包括其关键的行业驱动因素、潜在的技术和应用,及其相关的研究进展。 结果 从学术和行业应用的角度讨论和比较了能源互联网与能源物联网的定义,并分析了面向能源物联网演进的一些主要阶段和需要关注的问题。 结论 文章为能源物联网的进一步研究和实践提供有益的参考。     

Meta-analysis of net energy return for wind power systems

This analysis reviews and synthesizes the literature on the net energy return for electric power generation by wind turbines. Energy return on investment (EROI) is the ratio of energy delivered to energy costs. We examine 119 wind turbines from 50 different analyses, ranging in publication date from 1977 to 2007. We extend on previous work by including additional and more recent analyses, distinguishing between important assumptions about system boundaries and methodological approaches, and viewing the EROI as function of power rating. Our survey shows an average EROI for all studies (operational and conceptual) of 25.2 (n = 114; std. dev = 22.3). The average EROI for just the operational studies is 19.8 (n = 60; std. dev = 13.7). This places wind in a favorable position relative to fossil fuels, nuclear, and solar power generation technologies in terms of EROI.     

Optimization design of BCHP system to maximize to save energy and reduce environmental impact

The energetic and environmental performances of building cooling heating and power (BCHP) system are closely dependent on its design and operation strategy. This paper analyzes the energy consumptions of a conventional separation production (SP) system and a BCHP system respectively and constructs their corresponding environmental impact models. Furthermore, three energy-related environmental issues, global warming, acid precipitation and stratospheric ozone depletion, are assessed in the proposed emission model. To maximize the benefits (energy-saving and emission-reducing) achieved by the BCHP system in comparison to the SP system, genetic algorithm (GA) is employed to optimize the capacity of BCHP system in consideration of its operation mode. A numerical case of BCHP system for a hotel building is applied to ascertain the effectiveness of the optimal method and demonstrate the performances of the optimal BCHP system.     

七国集团与金砖四国能源结构变化特征及启示

七国集团和金砖四国在全球经济、政治和能源领域有着重要地位。本文分析了这些主要国家的一次能源生产和消费结构、终端能源消费结构、使用结构(按行业)、发电能源结构等的变化特征。资源禀赋、国际贸易的发展、技术进步、发展阶段等因素对各类能源结构的变化有着不同程度的影响或制约。环境恶化和全球气候变暖加快了低碳清洁能源的发展进程。     

节能服务 持续发展——中国节能协会节能服务产业委员会宗旨

本文介绍了中国节能协会节能服务产业委员会(简称EMCA)的筹备和成立的背景和基本情况,重点介绍了EMCA的宗旨和今后的主要工作设想。在世界银行和全球环境基金等国际机构的支持下,引进、示范和推广国外的基于市场的《合同能源管理》节能新机制,发展更多的节能服务公司(EMCo),形成中国的节能服务产业,这对中国的节能领域是一种新的理念、新的尝试。特别是近年来,我国电力、石油等能源供需矛盾比较突出,节能的必要性和重要性逐步为更多的人们所真正认识,EMCA的成立,适应了这种新形势的要求。让我们共同努力,办好EMCA,实现EMCA的宗旨,促进更多的新节能服务公司涌现出来,同时,节能服务的内容更加丰富多样,真正形成健康的可持续发展的中国节能服务产业。     

极小展弦比跨音速汽轮机叶片非定常流动机理研究

随着能源效率需求的不断提升,汽轮机叶片的设计在不同应用场景中展现出显著的多样性。大展弦比叶片因端壁损失较低、流动效率较高,广泛用于传统燃气轮机和工业汽轮机。然而,在空间受限或特殊工况下,例如航空发动机的高负荷小型化设计、船舶推进系中的高压级和调节级的应用场景,小展弦比叶片因其紧凑设计成为首选。尽管如此,小展弦比叶片在性能上仍存在明显短板。端壁二次流和混合损失等问题显著增加了能量损失,严重影响整体性能。本文基于跨音速条件下的极小展弦比汽轮机叶片,采用延迟脱体涡模拟（DDES）方法,深入研究了小展弦比叶片的流动特性,重点分析了涡流结构、激波与边界层干扰引发的流动分离及其对性能的影响。研究发现,小展弦比叶片虽然具有结构紧凑的优势,但其能量损失主要集中在尾缘区域,且尾迹涡、端壁涡与激波的相互作用是损失增加的关键因素。结果表明,DDES方法在捕捉小展弦比叶片中小尺度涡流和瞬时现象方面表现出显著优势,能够更准确地反映激波的平均扰动效应及涡流对整体性能的影响。此外,本文还提出了针对极小展弦比叶片性能优化的未来方向,包括优化尾缘形状、调整端壁区域设计、减少激波干扰以及控制边界层分离等略。本研究为小展弦比叶片的性能优化提供了理论支持,同时展示了DDES方法在复杂流动模拟中的巨大优势。未来研究将进一步验证这些优化方案的可行性,以有效降低能量损失并提升汽轮机的整体效率。     

应用冷冻机控制减少TEWI

介绍了制冷剂对环境影响的综合评价指标ODP及TEWI,从使用电力的角度考虑,提出冷冻机控制对于减少TEWI的有效性。     

新能源项目LCOE度电成本与IRR内部收益率的等效性分析

 随着国内新能源发电行业的发展,补贴退坡和资源竞争配置等政策的实施,全生命周期平准化发电成本（LCOE）越来越被大家关注和使用,但行业内对LCOE的计算标准不一,文章主要为了解析其与内部收益率（IRR）的关系,来提高大家对LCOE度电的认识以及规范LCOE度电成本的使用。  文章先对两者的特点和应用场景做了分析,然后通过两者计算公式的简化和转换,分析固定IRR反算电价和LCOE度电成本在模型上的差异和联系。最后通过某海上风电的实例分析,计算两者结果的实际差距,并分析造成这些差异的因素及敏感性。  从结果来看,简化条件后两者的计算模型十分接近,两者差异仅为所得税。通过实例分析,造成IRR反算电价和LCOE度电成本差异的因素有建设期增值税抵扣、增值税和所得税的税后优惠、附加税、融资情况,且这些因素的影响方向和程度都不同。可以认为,IRR内部收益率反算电价与LCOE度电成本在原理上是近似的,但受到国内财税制度的影响,输入参数、边界条件的增加使得两者出现了差异。  建议通过主管部门、行业协会等对LCOE进行适当的本地化修正,并结合环境影响成本和电力系统影响成本,使其可以横向比较不同发电形式的经济性,也可以在特定工程中,实现不同方案的经济性快速比较。     

A novel optimization sizing model for hybrid solar-wind power generation system

This paper develops the Hybrid Solar-Wind System Optimization Sizing (HSWSO) model, to optimize the capacity sizes of different components of hybrid solar-wind power generation systems employing a battery bank. The HSWSO model consists of three parts: the model of the hybrid system, the model of Loss of Power Supply Probability (LPSP) and the model of the Levelised Cost of Energy (LCE). The flow chart of the HSWSO model is also illustrated. With the incorporated HSWSO model, the sizing optimization of hybrid solar-wind power generation systems can be achieved technically and economically according to the system reliability requirements. A case study is reported to show the importance of the HSWSO model for sizing the capacities of wind turbines, PV panel and battery banks of a hybrid solar-wind renewable energy system.     

Cascade utilization of chemical energy of natural gas in an improved CRGT cycle

In this paper three advanced power systems: the chemically recuperated gas turbine (CRGT) cycle, the steam injected gas turbine (STIG) cycle and the combined cycle (CC), are investigated and compared by means of exergy analysis. Making use of the energy level concept, cascaded use of the chemical exergy of natural gas in a CRGT cycle is clarified, and its performance of the utilization of chemical energy is evaluated. Based on this evaluation, a new CRGT cycle is designed to convert the exergy of natural gas more efficiently into electrical power. As a result, the exergy efficiency of the new CRGT cycle is about 55%, which is 8 percentage points higher than that of the reference CRGT cycle. The analysis gave a better interpretation of the inefficiencies of the CRGT cycle and suggested improvement options. This new approach can be used to design innovative energy systems.     

利用含水层储能的水源热泵工程及其对环境影响的评估

含水层储能系统(ATES)作为一项节能技术,其发展始于20世纪60年代的上海,是当今世界缓解能源短缺的方法之一。将其与水源热泵联合运转,同传统的夏季用制冷机、冬季用供暖锅炉的系统相比,不但可节约大量能源,还可减少燃料燃烧产生的CO2、SO2等气体的排放,具有节能与环保双重效益。文章从开发ATES工程项目的角度出发,结合应用实例介绍了ATES系统,以及如何就ATES系统对环境的影响进行全面的评估。     

Thermodynamic analysis of waste heat power generation system

In the present work, a waste heat power generation system is analyzed based on the criteria with and without considering the heat/exergy loss to the environment. For the criteria without considering the heat/exergy loss to the environment, the first- and second-law efficiencies display different tendencies with the variations of some system parameters. When the heat/exergy loss to the environment is taken into consideration, the first and second law efficiencies display the same tendency. Thus, choosing the appropriate expressions for the performance criteria is crucial for the optimization design of the waste heat power generation system. It is found that there are two approaches to improving the system performance: one is to improve the heat/exergy input; the other is to enhance the heat-work conversion ability of the system. The former would deteriorate the environment if the heat-work conversion ability of the system remains unchanged; the latter could reduce the environmental impact but it’s restricted by the heat/exergy input. Therefore, the optimal operation condition should be achieved at the trade-off between the heat/exergy input and the heat-work conversion ability of the system.