被动式太阳房

第一讲一、被动式太阳房的原理和分类所谓太阳房是指利用太阳的辐射能量代替部分常规能源、使建筑物达到一定温度环境的一种建筑。太阳房有主动式和被动式之分,被动式太阳房不需要任何主动式太阳房所必须的部件(太阳集热器,热交换设备、管道、水泵、风机等),仅仅依靠建筑方位的合理布置和通过窗、墙、屋顶等建筑物本身构件,以自然热交换方式(辐射、对流、传导)来获得太阳能。如果获得的太阳能达到建筑采暖、空调所需能     

太阳电池材料的极限参数

本文从能带理论出发,讨论了各种太阳电池材料的光电转换极限参数。依据普遍采用的AMO和AM1.5太阳光谱数据,用电子计算机计算了各种太阳电池材料所能获得的极限光电流密度、极限输出功率密度和极限光电转换效率。最后列表讨论了硅(包括非晶硅)、砷化镓、硫化镉、磷化铟等数种重要光电材料的极限参数。     

基于EMD-TCN的多能供热系统太阳辐照度预测模型

针对太阳辐照度的非平稳性和非线性影响多能供热系统运行效率和可靠性问题,该文提出一种基于经验模态分解（EMD）和时间卷积网络（TCN）的太阳辐照度混合预测模型EMD-TCN,更精准地从气象数据中提取太阳辐照度非线性和非平稳的隐含特征,获得更佳的预测精度。该研究利用逐时气象数据对所提出的EMD-TCN模型进行不同时间尺度的太阳辐照度预测实验,并与4种主流深度学习预测算法进行对比分析,结果表明该太阳辐照度预测模型具有更高的预测精度和泛化能力。     

硅电池辐照计非线性模型与散射模型的修订

文章针对高、低太阳辐照度情况下,硅电池辐照计测量数据失真,以及太阳散射辐照度计算模型中水平面与倾斜面太阳辐照度比值系数较为单一,不能满足多种天气情况下太阳散射辐照度的测量需求,提出了电压与非线性太阳辐照度计算模型的修订方法,以及适应多种天气情况的太阳散射辐照度修正系数的修订方法。实验结果表明,对于修订后的非线性太阳辐照度计算模型以及太阳散射辐照度修正系数得到的实验数据,其中,80%的实验数据的误差在±10%之间,因此,文章的模型和修正系数均比较合理,可适应多种天气情况,并提高了硅电池辐照计测量结果的可靠性。     

86’太阳能旅行和梅林大奖赛

被称为“太阳能旅行”的太阳车竞赛的创始人是瑞士的约瑟夫·廷尼。1985年在瑞士举行了第一次“太阳能旅行”大赛。它对于热情的太阳车制造者和公众来说,已经成为一种有力的推动。按照延尼的想法,参加竞赛的车大部分动力应来自太阳能光电流。“86’太阳能旅行”分为六段进行。第一段从西德布赖斯高的弗赖堡开始,到瑞士的巴塞尔市。第二段     

窗户型多重温室太阳能热水系统

提出一种可从阳台窗户上同时供给家庭所需的开水和热水两种水的太阳能开水热水系统.将太阳热水器同时与日光温室和建筑物相结合,将日光温室改造成多重温室,并安装在建筑物窗户外面下端的墙壁上,在热性能、成本、安装维修、使用方便、使用寿命等绝大多数方面,都优于真空管太阳热水器.     

太阳能的能源

太阳能的能源是来自地球外部天体的能源（主要是太阳能），是太阳中的氢原子核在超高温时聚变释放的巨大能量，人类所需能量的绝大部分都直接或间接地来自太阳。     

太阳能地面采暖系统蓄热水箱容积分析

通过分析太阳能采暖系统所需蓄热鼍与建筑热负荷、太阳能集热量日变化规律之间的关系,得出太阳能采暖系统所需蓄热水箱容积的理论算式.根据拉萨、银川、西宁、西安等地的太阳辐射强度及建筑热负荷的日变化规律,模拟得出系统所需蓄热量变化规律;并对各种蓄热温差下对应的蓄热水箱容积进行了模拟分析,结果表明:太阳能采暖系统所需蓄热量随太阳集热器的集热量与建筑热负荷之间的差值增大而增加;蓄热水箱容积随蓄热温差增大而减小,当蓄热水温达到80℃时,在各种地面采暖系统取水温度下,单位集热器面积所需蓄热水箱容积趋于相等.     

太湖山丘区典型小流域AnnAGNPS模型数据库建立研究

以太湖流域山丘区宜兴梅林小流域为例,采用物理机理模型 AnnAGNPS与ArcView交互界面获得模型运行所需的地理参数,并将较易获得的数据转换成模型所需气象、土壤、作物等参数形式,建立了模型运用数据库,可供类似研究借鉴.     

基于时频分析法的智能电网电压闪变分量运算

为获得电网电压闪变治理中设备参数调整和控制策略制定过程中所需的准确可靠电压闪变数据,将一种非线性和非平稳信号时频分析法(HHT变换)成功引入电压闪变低幅调制信号瞬时相位、瞬时幅值、瞬时频率等特性参数的检测中,可从时域和频域两方面对信号进行同时分析。将电压闪变信号调制获得的低频信号,先用EMD分解算法分解成若干IMF分量,再做HHT变换。算例仿真分析表明,该优化算法提取电压闪变信号数据可行有效,数据准确,能满足工程需求。     

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.