节能降耗的电力计量技术的应用

电力能源的消耗是我国社会发展的重要组成部分,其对国民经济的增长和人民生活水平的提高具有十分重大的意义和作用.为了实现节能降耗的目的,就需要采用合理的措施来进行节能的计量工作,其中,供电计量的准确与否是影响电能质量的关键因素.因此,如何有效的控制电力的能耗就成为了必须要解决的问题.     

完全电力调度监控的可靠性问题与对策分析

当前的城市建设、区域规划过程中,电力产业的革新是非常重要的手段,所有的工作开展都要借此来得到卓越的成果,并且在一系列的问题处置上不能放松,必须在电力调度监控的可靠性方面积极的转变.电力行业的发展速度正不断的加快,所有的电力工程、电力项目,都要在监控的措施上不断的增加,发现任何问题都要快速的解决.电力调度监控的策略,在于...     

换热站控制策略优化与节能的探讨

节能技术的应用成为现阶段我国供热行业的热门话题和关注的焦点。换热站作为供热系统连接管网与用户的一个重要环节,换热站的自动化程度和换热站的控制策略对系统的运行有着至关重要的作用,同时对热网的节能也有很重要的影响。结合换热站自动控制国内外的发展现状,介绍供热系统的调节方式,对换热站的控制策略进行优化。优化换热站的控制策略不仅可以提高换热站的供热品质,还可以实现节能目标,提升经济效益。     

制冷剂环境影响及可持续发展浅析

论述了当前使用的制冷剂以及存在的问题,指出现行制冷剂对臭氧层的破坏作用及引起的温室效应,将严重影响环境的可持续发展。总结了当前制冷剂的替代工作及取得的成果。在论述可持续发展概念的基础上分析了制冷剂的替代研究与环境的可持续发展的关系,得出了环境的可持续发展的要求推动了制冷剂的替代研究工作,并为替代研究指明了方向,同时制冷剂的替代进一步促进了环境的可持续发展。总结了在环境可持续发展要求下的制冷剂的发展趋势。     

轻钢结构房屋在节能环保方面的分析研究

随着社会的发展和进步,我国的各行各业都处于快速发展当中.但同时迅速发展的经济也给生态环境造成了一定的破坏.为了未来更好的发展.我国开始走可持续发展的道路.即将节能环保作为我国发展的战略部署之一.住房一直是人们日常生活当中不可缺少的重要组成部分.传统的房地产开发行业会对周围的环境造成一定的损害.扬起的粉尘还有施工遗留下的...     

摩托车排放耐久劣化系数的误差分析

介绍了摩托车排放耐久的劣化系数DF的测试计算过程,分析了排放耐久过程的排放测试值的随机误差对最终计算的劣化系数DF的影响,给出了排放测试值设定随机误差范围下对应的劣化系数DF的分布范围及对应的概率,提出了减小测试值的随机误差对最终计算的劣化系数DF影响的方法。     

工业齿轮油的现状及发展趋势

随着齿轮设备的发展和使用环境的变化,机械设备对齿轮润滑的要求不断提高。齿轮油也随着工业设备的发展,质量不断提高。齿轮油的发展经历了从原来的低性能发展到现在的到高性能,从定期换油到免维护的发展过程。齿轮油的高性能离不开高性能添加剂和添加剂的复配,因此齿轮润滑油添加剂的发展是未来齿轮油高性能化的基础。随着齿轮油标准化的完善,齿轮油的使用更加规范。而随着环保的要求,可降解的合成油和植物油也开始在工业齿轮中应用。     

浅谈包头黄河水处理

近些年来,随着城市建设以及经济的发展,内蒙古行政区内的包头市人口不断增加,使得城市90％的饮用水来自黄河。因此,水的质量问题是非常重要的。随着工业生产的不断发展,大量的生产和生活污水的排放造成严重的土壤,地表水的污染以及地下水环境的破坏。     

城镇污水处理厂节能降耗研究现状及发展趋势

污水处理属于能耗密集型的行业,我国的污水处理能耗大约占用社会电能耗的0.3%,因此探究污水处理工艺的节能措施有利于节约社会资源。当前我国的污水处理厂的基础设施正在不断的完善,为来污水处理厂运行中的节能消耗需要构建全程优化和精细化的管理体系,实现污水处理的节能。城镇污水的处理与我国建设绿色低碳环保节能的家园有着密切的关系。在研究城镇污水处理节能措施的基础上,分析其节能技术的途径以及未来城镇污水处理的发展趋势。     

发动机气缸套深滚压强化处理技术研究

发动机气缸套支撑肩退刀槽部位是气缸套结构最薄弱的环节,支撑肩疲劳失效产生的掉台失效是发动机事故最严重的故障之一,气缸套瞬间断裂,高速运转的活塞及连杆击碎缸套的碎片有可能击穿机体,造成严重的事故。随着发动机向高速、高压方向的发展,对气缸套的疲劳强度提出更高的要求,如何利用有效的手段,在不增加气缸套成本的前提下提高气缸套的寿命,是气缸套厂家的重点研究方向。滚压技术作为一种提高金属疲劳强度的一种手段已在很多方面得到应用,目前存在的问题是如何针对不同的产品定量定性的生产、检测、指导气缸套的滚压效果,目前没有这方面具有指导意义的详细的数据及公式。我们根据长期、大量的对气缸套滚压试验生产数据总结出的一套指导生产的工艺参数、过程监测、效果评价体系,形成了一套指导生产实际的规范性文件,对气缸套的滚压技术具有较深的指导意义。     

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%.     

Contents in Volume 23,2014

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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。     

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.