褐煤造气锅炉的设计特点

文章主要介绍褐煤气化的产生机理，燃褐煤煤气锅炉的设计构想、设计特点、经济价值。     

燃用印尼褐煤的循环流化床锅炉设计与运行

印尼褐煤在发电行业的市场需求广阔。以印尼某项目为例,分析了燃用印尼褐煤的CFB锅炉的方案设计,介绍针对煤种低灰分、高水分等特点采取的一系列应对措施,总结了锅炉运行特点,为其他燃用印尼褐煤CFB锅炉的设计和运行提供参考。     

超临界燃褐煤塔式锅炉技术

针对褐煤广泛应用于我国电站锅炉的市场前景,介绍了哈尔滨锅炉厂有限责任公司采用自主技术设计的国内首台660 MW等级超临界塔式褐煤锅炉技术特点。同时,针对塔式褐煤锅炉运行数据,结合性能,进行经济分析;该技术也为今后燃褐煤发电机组高效率、低NOx排放设计提供了宝贵的经验;通过对比分析,此技术各项指标已经达到国内领先水平,并实现国内燃褐煤塔式锅炉零的突破,为将来更好地利用国内褐煤奠定了基础。     

燃用褐煤的大容量CFB锅炉运行实绩

对国产首台燃用褐煤的135MW等级循环流化床锅炉的设计特点及运行实绩进行了较详细的介绍,并结合燃用褐煤及高海拔低气压等设计条件进行了分析研究。     

大容量褐煤锅炉技术的最新发展

本文介绍国内褐煤锅炉的技术情况以及最新的技术发展,简要介绍了近期几个典型褐煤炉型的结构及技术特点,初步分析了高参数燃用褐煤电站锅炉今后的技术发展方向。     

大容量褐煤锅炉

随着电力需要不断增长,燃褐煤锅炉容量从500/时增加到1000吨/时,最近将达2000吨/时。当褐煤燃烧时由于燃料中含高的水价,烟气容积几乎比同容量燃石煤锅炉大二倍,60万瓩的燃褐煤锅炉外形尺寸约等于100万瓩的燃石煤锅炉外形尺寸。但对燃褐煤锅炉来说,炉膛热负荷具有很重要意义,同时应仔细地设计炉膛和燃烧装置(如燃烧     

220t／h高温,高压,纯燃高炉煤气锅炉设计

随着高炉的大型化使高炉煤气的产量成倍增加，原有的中、低参数燃用高炉煤气的锅炉已不能适应煤气产量增加的需要。因此，开发高温、高压、纯燃高炉煤气已成必要。该文作者就杭州锅炉厂在设计、制造２２０ｔ／ｈ高温、高压锅炉中遇到的高炉煤气的燃烧特性、燃用高炉煤气对锅炉整体布置的影响等问题作了介绍，并提出了解决问题的措施和方法。     

全燃和掺燃高炉煤气炉的比较研究

由于高炉煤气中含有大量的惰性气体 ,可燃成分少 ,发热值低 ,燃料产物的体积流量大 ,因而使大容量高压燃煤气锅炉各受热面的传热特性与燃煤锅炉相比发生很大的变化。针对 5 0MW高压锅炉全燃和掺燃高炉煤气2种炉型的特点进行了详细的分析讨论 ,并与燃煤锅炉进行了比较研究 ,阐述了燃用高炉煤气锅炉的热工参数、传热特性以及受热面布置的特点 ,为研究和设计燃用高炉煤气炉提供了可靠的实践数据和理论依据。     

燃用超低热值褐煤大容量锅炉的设计与开发

本文介绍了燃用超低热值褐煤锅炉的主要方案,阐述了该方案在技术参数、结构布置等方面的技术特点。     

高炉煤气蓄热稳燃技术在锅炉中的运用

文章介绍了高炉煤气的燃烧反应机理,以及高炉煤气锅炉炉内蓄热稳燃装置的结构和工作原理,并通过工程实例对蓄热稳燃技术加以说明,在锅炉中运用高炉煤气蓄热稳燃技术,有利于高炉煤气的燃烧和燃烬.     

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。     

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.     

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.