高效三功能层单晶薄膜太阳电池的研究

讨论了ZnSe/GaAs/Ge等三功能层梯度掺杂异质单晶薄膜复合光电极的结构,分析了把它用于光电化学太阳电池、光伏太阳电池、肖特基光伏太阳电池时的工作机理及优点.实验结果验证了理论分析.在进一步提高太阳电池转换效率方面,该复合光电极值得进一步研究.     

高效非晶硅叠层太阳电池的优化设计

研究了高效ａ－Ｓｉ／ａ－Ｓｉ／ａ－Ｓｉ－ＳｉＧｅ三结太阳电池的优化设计。电流匹配是影响二端子叠层太阳电池填充因子的关键因素，在内电极的ｐ／ｎ界面外附加载流子复合是由少数载流子浓度、界面态和ｐ／ｎ界面处材料的几何因素匹配决定的。利用适当的带隙匹配和ｉ层厚度匹配来实现ａ－Ｓｉ／ａ－Ｓｉ／ａ－ＳｉＧｅ三结太阳电池结构的最佳化，同时采用改善ｎ／ｉ界面特性的缓冲层技术，获得了Ｖｏｃ＝２．４８Ｖ，Ｊｓｃ＝６．     

国际发展态势─砷化镓太阳电池实用化

国际发展态势─砷化镓太阳电池实用化于培诺ＧａＡｓ／ＧａＡｓ太阳电池许多光伏专家先后开展了以砷化锌（ＧａＡｓ）单晶材料为基底的太阳电池研制工作。根据太阳辐射光谱和各种半导体材料的带隙可以计算出最佳光电转换效率所对应的材料最佳带隙是１．ｓｅＶ。现在已开发...     

n—CdS／p—CulnSe2异质结二极管电流传输机制的研究—计算机模拟分析

应用Ｓｃｈａｒｆｅｔｔｅｒ－Ｇｕｍｍｅｌ解法数值求解电子、空穴连续性方程和泊松方程，对ＣｄＳ／ＣｕＩｎＳｅ２异质结的伏安特性进行计算机数值模拟。基于材料、器件参数的实验数据，我们的计算结果支持了ＣｕＩｎＳｅ２中的Ｓｈｏｃｋｌｅｙ＝Ｒｅａｄ空间电荷复合是控制ＣｄＳ／ＣｕＩｎＳｅ２异质结二极管正向电流主导的物理机制，进一步说明在提高ＣＩＳ太阳电池性能的努力中开展ＣｕＩｎＳｅ２化学缺陷研究的重要性。     

减反射膜玻璃对光伏组件光增益的分析

完善光伏组件光学模型,并根据模型理论模拟减反射膜玻璃和普通玻璃对光伏组件光增益的大小,通过分析发现当太阳光垂直光伏组件入射时,普通玻璃封装后,单晶硅太阳电池封装后光增益小于多晶硅太阳电池,减反射玻璃对多晶硅太阳电池片的光增益大于对单晶硅太阳电池的光增益。     

n－CdS／p－CulnSe_2异质结二极管电流传输机制的研究──计算机模拟分析

应用Ｓｃｈａｒｆｅｔｔｅｒ－Ｇｕｍｍｅｌ解法数值求解电子、空大连续性方程和泊松方程，对ＣｄＳ／Ｃｕｌｎｓｅ。异质结的伏安特性进行计算机数值模拟。基于材料、器件参数的实验数据，我们的计算结果支持ＴＣｕＩｎＳｅ。中的Ｓｈｏｃｋｌｅｙ－Ｒｅａｄ空间电荷（ＳＲＳＣ）复合是控制ＣｄＳ／ＣｕＩｎＳｅ。异质结二极管正向电流主导的物理机制，进一步说明在提高ＣＩＳ太阳电池性能的努力中开展ＣｕＩｎＳｅ。化学缺陷研究的重要性。     

关于发布《太阳能户用光伏电源系统和风-光互补发电系统的技术条件》和开展部件检测及提供设计咨询技术服务的通知

为使读者了解“国家经贸委、全球环境基金／世界银行中国可再生能源商业化发展促进项目”进展情况,现将该项目办公室发布的通知作一报道,供大家参考。———编者———为做好全球环境基金（ＧＥＦ）／世界银行中国可再生能源商业化发展促进项目（以下简称世行项目）实施准备,保证太阳能户用光伏电源系统产品质量,国家经贸委世界银行项目办公室组织中外专家编制了《太阳能户用光伏电源系统和风光互补发电系统的技术条件》（以下简称《技术条件》）和《太阳能户用光伏电源系统用太阳电池组件质量认证检验实施细则》、《太阳能户用光伏电…     

小面积染料敏化纳米薄膜太阳电池的优化研究

论述了对小面积染料敏化纳米薄膜太阳电池各个组成部分优化实验的研究,主要包括纳米TiO2多孔薄膜、染料光敏化剂、电解质、反电极及其它工艺的优化选择。通过对电池各种参数的优化和实验,获得了8.73%的光电转换效率。实验结果表明,小面积电池的实验是研究染料敏化纳米薄膜太阳电池光伏性能的一种极好的途经,将为保证大面积DSCs的光伏性能和将来的产业化打下良好的基础。     

p／i界面的缓变层对大面积（2790cm^2）a—Si：H太阳电池性能影响的研究

报道了在大面积（２７９０ｃｍ２）ｐ－ｉ－ｎ型ａ－Ｓｉ∶Ｈ异质结太阳电池ｐ／ｉ界面之间引入缓变层（ＣＧＬ∶Ｃ，ＣＧＬ∶Ｂ∶Ｃ）对电池性能影响的研究结果。实验发现，带有ＣＧＬ∶Ｃ的ａ－Ｓｉ∶Ｈ太阳电池性能的改善主要来源于开路电压的提高，带有ＣＧＬ∶Ｂ∶Ｃ的ａ－Ｓｉ∶Ｈ太阳电池性能的提高主要来源于填充因子ＦＦ的增加。提出了带有缓变层ａ－Ｓｉ∶Ｈ电池的能带模型，据此分析了ｐ／ｉ结附近载流子的复合动力学过程，从理论上解释了实验中所发现的现象。     

浅析非晶硅太阳电池优势及其在路灯上的应用

从年发电量、能量回收期和应用范围三大方面分析非晶硅太阳电池相对于晶体硅太阳电池的优势,并对非晶硅太阳电池较晶体硅太阳电池年发电量多的原因进行了分析。最后提出在太阳能路灯中采用非晶硅-晶体硅复合光伏组件供电方式,可降低太阳能路灯光伏组件的功率配置,减小蓄电池容量配置和放电深度,缩短欠压后恢复期,延长蓄电池的使用寿命。     

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。     

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.