300MW、600MW火电汽轮机的寿命管理

阐述国内外300MW,600MW火电汽轮机制造厂的寿命分配及关键设备管理措施。     

600MW空冷汽轮机的设计开发

简要介绍了本公司新开发的三缸四排汽600MW空冷汽轮机.通过对系统、结构及新技术应用的介绍可知,该600MW空冷汽轮机结构合理,技术先进,性能优越,安全可靠,达到世界先进水平,填补了我公司600MW系列汽轮机的一个空白.     

300MW等级汽轮机通流部分改造综述

介绍了国内在役300MW等级汽轮机组存在的主要问题.对比了国内主要汽轮机制造厂及相关科研机构在汽轮机通流部分改造中使用的新的设计、制造技术,比较了已经完成的300MW等级通流改造项目的效果,为进一步节能降耗提供参考性意见.     

600 MW级超临界机组通流改造方案比较

分析了目前国内超临界600 MW级汽轮机存在的主要问题,论述了超临界汽轮机通流改造在进排汽、本体结构、密封技术、中低负荷提效优化方面的技术特点,比较了主要改造厂家改造效果,给出了600 MW超临界汽轮机通流改造的原则和改造范围以及通流改造在设计边界条件、保证热耗率选取等方面应注意的问题,为发电企业实施600 MW级超临界汽轮机通流改造工作提供参考。     

引进型300MW,600MW汽轮机低压缸优化设计

1、发展概况低压缸的设计直接决定了机组的经济性及功率等级,因此历来是技术发展的重点方面。近十几年来各国汽轮机制造公司,如日本日立、东芝、三菱、美国西屋、ABB、AA等都推出了新一代具有高经济性的大功率低压缸。目前引进型亚临界300MW、600MW汽轮机的低压缸是按美国西屋公司技术制造的,其积木块代号为BB074。该积木块是由     

600MW三缸四排汽直接空冷汽轮机的设计开发

简要介绍了东方600MW三缸、四排汽直接空冷汽轮机的特点，适当分析了空冷对汽轮机本体结构的影响，以及在汽轮机设计时所采取的一些措施，从而说明该600MW空冷汽轮机结构合理，技术先进，性能优越，安全可靠。     

高效新型220 MW亚临界汽轮机优化选型分析

以越南某2×220 MW火力发电厂工程的设计、采购、施工(EPC )合同要求为出发点,从技术、能耗方面进行分析,根据国内200 MW等级超高压汽轮机和300 MW等级亚临界汽轮机的特点,通过分析比较两者的差别,提出了220 MW等级汽轮机可采用亚临界参数方案,通过优化叶片型式,减少轴封漏气,提高汽轮机汽缸效率,汽轮机热耗降低至8 026 kJ/kWh,并最终在工程中顺利实施。机组投运后,每年可节约10 161.5 t标煤,提高了机组的经济性,创造了较大的经济效益,可为后续同类项目的汽轮机选型提供参考。     

吴泾第二发电厂600MW汽轮机的主要特点及动行概况

通过对吴泾第二发电厂600MW汽轮机的总体结构、通流部分、轴系与支承、优化项目介绍及电厂运行概况介绍,用数据说明我公司对引进型600MW汽轮机的优化设计是合理、成功的,机组的技术性能和经济性等不仅在国内处于领先水平,而且还达到了国际上同类机组的先进水平.     

亚临界600MW两缸两排汽直接空冷汽轮机的研制

介绍了东汽亚临界600MW两缸两排汽直接空冷汽轮机的特点,详细分析了34＂空冷末级叶片和两排汽空冷低压模块的性能特点。从而说明该600MW空冷汽轮机结构合理、技术先进、性能优越、安全可靠。     

大容量抽汽机组设计介绍

介绍了一款新型汽轮机——亚临界600MW可调整抽汽凝汽式汽轮机。通过对黄骅电厂600MW抽汽凝汽式汽轮机的介绍,阐述该大功率600MW亚临界可调整抽汽凝汽式汽轮机具有结构先进、布置合理、运行灵活、性能优越、安全可靠的特点。该机型的推出,为今后大功率抽汽汽轮机的研发积累了经验,同时为用户带来更多的选择机会。     

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.     

Contents in Volume 23,2014

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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.