节能工作需要明确理论基础避免战略误区

为落实单位GDP能耗在未来5年内降低20%的目标,我国开始了大规模节能工作。本文认为我国的节能工作可能在几个方面存在误区,比如对能源的特殊性缺乏了解,节能政策的制定与实施缺少针对性,过分偏重产业部门而忽视其他非产业能源消费部门,过分强调产业结构的调整,而忽视整体结构,特别是消费结构的调整等。我国的节能工作需要明确理论基础,在市场化、工业化、城市化和国际化的大背景下,开展有效的工作。因为能源消耗既是一个物理现象又是一个经济活动,本文首先从物理学和经济学两方面对节能的理论基础做了探讨。从物理学的角度,本文通过对“信息不遵守热力学定律”这一被物理学界称为“麦克斯韦妖”的现象的分析,为节能工作提出了用“无限的信息替代有限的能源资源,尽量降低熵增率”的物理学理论依据。文章继而通过单元生产过程的“能源-信息-材料”三要素模型,单位GDP能耗变化分解方法等,从经济学的角度阐述了以信息代替能源,经济增长应从能源资源密集型的旧模式向信息知识密集型的新模式转变的原理,为我国“以信息化带动工业化,走新型工业化道路”,通过单位GDP能耗的“隧道战略”赶上发达国家的战略设想提供了理论基础。最后,基于理论上的探讨和对中国节能实践的观察,本文为我国的节能工作提出了8个方面的建议。     

我国能源科技发展思路

能源是国民经济和社会发展的不可缺少的生产要素和物质基础。当前我国正处在工业化过程中,能源科技的发展将强有力的支撑国家能源安全。我国已成为世界能源生产和消费大国,预测2020年中国一次能源的需求为29亿tce,有可能继续实现能源翻一番,GDP翻两番。根据我国资源情况及国内外形势,笔者提出"节能优先,以煤为主,保障安全,多元发展"的可持续发展能源战略。能源科技发展的思路主要包括:要坚决贯彻节能优先的方针,加强煤炭的清洁、高效开发与利用研究,加强以油气为主的能源安全保障体系研究,实施多元化科技发展战略。据此战略思路,最后笔者尝试性的提出能源科技方面重点研究方向。     

《德国2050年能源效率战略》对我国的启示

德国政府十分重视通过节能和发展可再生能源实现能源转型。为进一步推进其能源转型,实现其气候中和目标,德国出台了《德国2050年能源效率战略》,提出了节能提高能效中长期目标,并在工业、建筑、交通等各个行业作出具体部署。德国作为全球能源转型的典范,其在节能上的相关举措对我国有一定借鉴意义。重点分析研究了《德国2050年能源效率战略》及其相关举措,从强化“能效优先”理念、制定中长期战略、出台奖惩措施、利用科技手段,推动节能降碳发展四个方面对我国的节能发展提出了相关政策建议。     

国务院关于加强节能工作的决定

各省、自治区、直辖市人民政府,国务院各部委、各直属机构:为深入贯彻科学发展观,落实节约资源基本国策,调动社会各方面力量进一步加强节能工作,加快建设节约型社会,实现“十一五”规划纲要提出的节能目标,促进经济社会发展切实转入全面协调可持续发展的轨道,特作如下决定:1、充分认识加强节能工作的重要性和紧迫性(一)必须把节能摆在更加突出的战略位置。我国人口众多,能源资源相对不足,人均拥有量远低于世界平均水平。由于我国正处在工业化和城镇化加快发展阶段,能源消耗强度较高,消费规模不断扩大,特别是高投入、高消耗、高污染的粗放型…     

构建城市低碳能源体系的国际经验与中国行动

本文探讨了构建城市低碳能源体系的理论基础,提出生态经济学是重要的理论支撑。随后,以英国、丹麦和日本等先行发展低碳经济国家为例,介绍了国际上构建低碳城市的有益经验,包括节能减排、优化能源结构、开发利用新能源和可再生能源等方面的经验。论文最后提出了中国构建城市低碳能源体系的三大行动:1)最大限度地利用"零排放"的新能源、可再生能源,推进能源结构低碳化;2)常规能源开发、输送、加工转换过程的低碳化;3)立足于能源供给端与能源需求端主动配合,加强节能减排的监管。     

回顾和展望——十年节能成就和今后任务

能源是发展社会经济的重要物质基础,是提高和改善人民生活的必要条件,能源利用程度是反映人类科学技术水平进步的一个重要标志。我国是一个能源生产大国,能源的生产建设和消费将直接制约着我国国民经济的发展速度,关系到本世纪末能否实现第二步战略目标使国民经济翻两番的重要因素。要保证国民经济长期持续、稳定、协调的发展,必须认真贯彻“开发和节约并重,近期把节约放在优先地位”的方针,最近江泽民同志为“全国节能宣传周”题词:“节约能源,保护资源,造福子孙”;李鹏同志题词:“节约能源是我国经济发展的一项长远战略方针”。中央领导同志从战略高度,提出对节能工作的指示,为我们今后工作更明确的指出了方向。     

从经济学角度看山西能源的可持续发展

可持续发展经济学的理论观点将自然因素纳入了经济学研究的范围 ,力图构建实现可持续发展的理论体系 ,以确立可持续发展观。以山西省能源资源为研究对象 ,从可持续发展的经济学理论观点入手 ,分析了能源发展所面临的现实情况 ,从经济学角度提出了实现我省能源可持续发展的思路 ,并给出了一些具体的建议     

欢迎订购《节能手册2013》

正本书以全新的节能理念和视角,在广泛收集国内外信息和总结我国节能工作实践的基础上,提供大量最新事实和数据,介绍节能新思想、新机制和新技术,从经济、社会、资源、环境等方面系统阐述了我国能源供应和消费,工业、交通运输、建筑等部门的节能现状,节能政策措施,并附有能源数据、低碳技术、国际组织和能源计量     

欢迎订购《节能手册2013》

正本书以全新的节能理念和视角,在广泛收集国内外信息和总结我国节能工作实践的基础上,提供大量最新事实和数据,介绍节能新思想、新机制和新技术,从经济、社会、资源、环境等方面系统阐述了我国能源供应和消费,工业、交通运输、建筑等部门的节能现状,节能政策措施,并附有能源数据、低碳技术、国际组织和能源计量     

欢迎订购《节能手册2013》

正本书以全新的节能理念和视角,在广泛收集国内外信息和总结我国节能工作实践的基础上,提供大量最新事实和数据,介绍节能新思想、新机制和新技术,从经济、社会、资源、环境等方面系统阐述了我国能源供应和消费,工业、交通运输、建筑等部门的节能现状,节能政策措施,并附有能源数据、低碳技术、国际组织和能源计量及换算。是从事节能环保行业科研、教     

Ash-forming elements in four Scandinavian wood species. Part 1: Summer harvest

Woody biomass in Finland and Sweden comprises mainly four wood species: spruce, pine, birch and aspen. To study the ash, which may cause problems for the combustion device, one tree of each species were cut down and prepared for comparisons with fuel samples. Well-defined samples of wood, bark and foliage were analyzed on 11 ash-forming elements: Si, Al, Fe, Ca, Mg, Mn, Na, K, P, S and Cl. The ash content in the wood tissues (0.2–0.7%) was low compared to the ash content in the bark tissues (1.9–6.4%) and the foliage (2.4–7.7%). The woods’ content of ash-forming elements was consequently low; the highest contents were of Ca (410–1340 ppm) and K (200–1310), followed by Mg (70–290), Mn (15–240) and P (0–350). Present in the wood was also Si (50–190), S (50–200) and Cl (30–110). The bark tissues showed much higher element contents; Ca (4800–19,100 ppm) and K (1600–6400) were the dominating elements, followed by Mg (210–2400), P (210–1200), Mn (110–1100) and S (310–750), but the Cl contents (40–330) were only moderately higher in the bark than in the wood. The young foliage (shoots and deciduous leaves) had the highest K (7100–25,000 ppm), P (1600–5300) and S (1100–2600) contents of all tissues, while the shoots of spruce had the highest Cl contents (820–1360) and its needles the highest Si content (5000–11,300). This paper presented a new approach in fuel characterization: the method excludes the presence of impurities, and focus on different categories of plant tissues. This made it possible to discuss the contents of ash element in a wide spectrum of fuel-types, which are of large importance for the energy production in Finland and Sweden.     

NEXT GENERATION ENGINEERED MATERIALS FOR ULTRA SUPERCRITICAL STEAM TURBINES

正1 ABSTRACT To reduce the effect of global warming on our climate,the levels of CO2emissions should be reduced.One way to do this is to increase the efficiency of electricity production from fossil fuels.This will in turn reduce the amount of CO2emissions for a given power output.Using US practice for efficiency calculations,then a move from a typical US plant running at 37%efficiency to a 760℃/38.5 MPa(1 400/5 580 psi)plant running at 48%efficiency would reduce CO2emissions by 170kg/MW.hr or 25%.     

Aerodynamic performance effects of leading-edge geometry in gas-turbine blades

The purpose of this paper is to illustrate the advantages of the direct surface-curvature distribution blade-design method, originally proposed by Korakianitis, for the leading-edge design of turbine blades, and by extension for other types of airfoil shapes. The leading edge shape is critical in the blade design process, and it is quite difficult to completely control with inverse, semi-inverse or other direct-design methods. The blade-design method is briefly reviewed, and then the effort is concentrated on smoothly blending the leading edge shape (circle or ellipse, etc.) with the main part of the blade surface, in a manner that avoids leading-edge flow-disturbance and flow-separation regions. Specifically in the leading edge region we return to the second-order (parabolic) construction line coupled with a revised smoothing equation between the leading-edge shape and the main part of the blade. The Hodson–Dominy blade has been used as an example to show the ability of this blade-design method to remove leading-edge separation bubbles in gas turbine blades and other airfoil shapes that have very sharp changes in curvature near the leading edge. An additional gas turbine blade example has been used to illustrate the ability of this method to design leading edge shapes that avoid leading-edge separation bubbles at off-design conditions. This gas turbine blade example has inlet flow angle 0°, outlet flow angle −64.3°, and tangential lift coefficient 1.045, in a region of parameters where the leading edge shape is critical for the overall blade performance. Computed results at incidences of −10°,   −5°,   +5°,   +10° are used to illustrate the complete removal of leading edge flow-disturbance regions, thus minimizing the possibility of leading-edge separation bubbles, while concurrently minimizing the stagnation pressure drop from inlet to outlet. These results using two difficult example cases of leading edge geometries illustrate the superiority and utility of this blade-design method when compared with other direct or inverse blade-design methods.     

Hydrogen production by steam-gasification of carbonaceous materials using concentrated solar energy – V. Reactor modeling,optimization, and scale-up

A chemical reactor for the steam-gasification of carbonaceous particles (e.g. coal, coke) is considered for using concentrated solar radiation as the energy source of high-temperature process heat. A two-phase reactor model that couples radiative, convective, and conductive heat transfer to the chemical kinetics is applied to optimize the reactor geometrical configuration and operational parameters (feedstock's initial particle size, feeding rates, and solar power input) for maximum reaction extent and solar-to-chemical energy conversion efficiency of a 5 kW prototype reactor and its scale-up to 300 kW. For the 300 kW reactor, complete reaction extent is predicted for an initial feedstock particle size up to 35 μm at residence times of less than 10 s and peak temperatures of 1818 K, yielding high-quality syngas with a calorific content that has been solar-upgraded by 19% over that of the petcoke gasified.     

汽轮机数字电液调节系统挂闸异常的技术完善

分析了200MW汽轮机数字电液调节系统在运行中存在的挂闸异常问题,采取了相应的技术处理措施,且运行实践效果良好。     

新型高压共轨ECU升压模块的数字化开发与优化

为了提高喷油器电磁阀的响应速率,提出了一种基于CPLD(复杂可编程逻辑器件)应用于高压共轨ECU的数字升压模块。鉴于该升压电路结构参数多,其升压电压的恢复响应要求高等特征,基于Pspice建立了升压电路的仿真模型,研究了不同电路参数下升压模块的输出特性,全面优化了该升压模块的性能。结果显示,该升压模块的最大转换效率可以达90%以上。在柴油发动机上对ECU的试验表明,升压电压最大波动不超过10%,其恢复时间仅为1.3ms,功率管最大温升仅为41℃,满足整机运行范围内ECU的需求。     

Contents in Volume 23,2014

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Trace metal chemistry and silicification of microorganisms in geothermal sinter, Taupo Volcanic Zone, New Zealand

As part of a pilot study investigating the role of microorganisms in the immobilisation of As, Sb, B, Tl and Hg, the inorganic geochemistry of seven different active sinter deposits and their contact fluids were characterised. A comprehensive series of sequential extractions for a suite of trace elements was carried out on siliceous sinter and a mixed silica-carbonate sinter. The extractions showed whether metals were loosely exchangeable or bound to carbonate, oxide, organic or crystalline fractions. Hyperthermophilic microbial communities associated with sinters deposited from high temperature (92–94°C) fluids at a variety of geothermal sources were investigated using SEM. The rapidity and style of silicification of the hyperthermophiles can be correlated with the dissolved silica content of the fluid. Although high concentrations of Hg and Tl were found associated with the organic fraction of the sinters, there was no evidence to suggest that any of the heavy metals were associated preferentially with the hyperthermophiles at the high temperature (92–94°C) ends of the terrestrial thermal spring ecosystems studied.     

Assessment methods of material ageing using Sdobyrev''s creep rupture model

The physical aspects of the activation energy, in higher and high temperatures, of the metal creep process were examined. The research results of creep-rupture in a uniaxial stress state and the criterion of creep-rupture in biaxial stress states, at two temperatures, are then presented. For these studies creep-rupture, taking case iron as an example the energy and pseudoenergy activation was determined. For complex stress states the criterion of creep-rupture was taken to be Sdobyrev's, i.e. σ_red = σ₁ β + (1 − β)σ_i, where: σ₁-maximal principal stress, σ_i-stress intensity, β-material constant (at variable temperature β = β(T)). The methods of assessment of the material ageing grade are given in percentages of ageing of new material in the following mechanical properties: 1) creep strength in uniaxial stress state, 2) activation energy in uniaxial stress state, 3) criterion creep strength in complex stress states, 4) activation pseudoenergy in complex stress states. The methods 1) and 3) are the relatively simplest because they result from experimental investigations only at nominal temperature of the structure work, however, for methods 2) and 4) it is necessary to perform the experimental investigations at least at two temperatures.     

Production of hydrogen from sewage biosolids in a continuously fed bioreactor: Effect of hydraulic retention time and sparging

Hydrogen was produced from primary sewage biosolids via mesophilic anaerobic fermentation in a continuously fed bioreactor. Prior to fermentation the sewage biosolids were heated to 70 °C for 1 h to inactivate methanogens and during fermentation a cellulose degrading enzyme was added to improve substrate availability. Hydraulic retention times (HRT) of 18, 24, 36 and 48 h were evaluated for the duration of hydrogen production. Without sparging a hydraulic retention time of 24 h resulted in the longest period of hydrogen production (3 days), during which a hydrogen yield of 21.9 L H₂ kg⁻¹ VS added to the bioreactor was achieved. Methods of preventing the decline of hydrogen production during continuous fermentation were evaluated. Of the techniques evaluated using nitrogen gas to sparge the bioreactor contents proved to be more effective than flushing just the headspace of the bioreactor. Sparging at 0.06 L L min⁻¹ successfully prevented a decline in hydrogen production and resulted in a yield of 27.0  L H₂ kg⁻¹ VS added, over a period of greater than 12 days or 12 HRT. The use of sparging also delayed the build up of acetic acid in the bioreactor, suggesting that it serves to inhibit homoacetogenesis and thus maintain hydrogen production.