附加阳光间型被动式太阳房供暖实验研究

通过对青岛地区附加阳光间型太阳房及相同结构的对比房室内温度及室外温度参数的监测,研究了寒冷季节室内温度随室外气象条件变化的情况。通过分析发现,在室内无热源及辅助热源条件下,附加阳光间型太阳房室内平均空气温度比对比房室内平均空气温度高3.8℃,最高温差达7.2℃,最低温差1.1℃。通过对附加阳光间型太阳房供暖节能率ESF分析计算得出其节能率较高的结论,证明了该地区改造被动式太阳房建筑的可行性和经济性。     

太阳能集热墙与地下室复合系统冬季供暖试验研究

提出一种适用于被动式太阳能空气供暖的地下室蓄热系统,并对西北严寒地区采用该系统的农村住宅进行供暖试验研究。通过试验,分析太阳能集热墙与地下室复合系统对室内热环境的影响。试验结果表明:有太阳能集热墙与地下室复合系统的房间内平均空气温度比对比房的室内空气平均温度高7.5℃,最高温差达13.6℃,最低温差为2.5℃。通过对太阳房供暖节能率的分析计算得出其节能率为62.3%,验证在该地区建立太阳能集热墙与地下室复合系统建筑的可行性和经济性。     

阿拉善牧区附加阳光间式太阳房模拟研究

用DeST-h软件建立附加阳光间被动式太阳房模型、模拟并得出该太阳房住宅一个采暖期室内逐时温度;整理、计算、对比太阳房与对比房室内平均温度,认为附加阳光间被动式太阳房在阿拉善牧区的应用是可行的。     

介绍一幢高寒地区农用被动式太阳房

一幢由附加阳光间,直接、间接受益型相结合的农用被动式太阳房于1988年初在青海省平安县落成。该地区海拔2244m,北纬36°35′,东经101°55′,属于高原较寒冷地区。当地气候干燥,年风沙量很大,太阳能辐射强度为586kJ/cm~2·a。冬季采暖期在室内完全无辅助热源的情况下,对该太阳房测试平均室温为11.7℃,太阳房平均室温高出对比房8.2℃,高出室外环境温度14.7℃,昼夜温度波动小,太阳能采暖效果明显,且宽敞明亮,受到了当地农户的普遍欢迎。     

浅谈被动式太阳房的应用

太阳房是直接利用太阳辐射能进行供暖。供热水或供冷的住宅。我们的祖先,将房屋砌向朝阳,开设大窗户,将阳光自然地引入室内取暖,这是最简单的太阳房;现代建筑利用太阳能进行供暖、空调、供热水、照明等,即成为现代的太阳房。１太阳房的种类 太阳房通常分为两大类。被动式和主动式,被动式太阳房,就是不用任何机械动力,将吸收的太阳能,通过空气自然循环向室内供暖。被动式太阳房具有清洁、自然舒适、构造简单、不消耗动力、造价低、故障少、维护容易等优点,但昼夜温差大,通常有直接阳光受益式、或南墙集热。蓄热墙式。主动式太阳…     

用热泵作被动式太阳房辅助热源的研究

北方寒冷地区，农村直接受益式被动式太阳房在采暖季节室内温度较低，舒适性差。本研究采用热泵辅助供暖的方式对被动式太阳房在采暖季节进行供暖实验。通过与煤炉、电加热器、分散式锅炉供暖的比较，验证了该方法的可行性。同时对热泵供暖进行优化，找出影响热泵供暖性能及年成本价格的因素，并对其在小城镇的推广做了分析。结果表明，热泵作为被动式太阳房在北方寒冷地区及电力充沛而集中供暖有困难地区的辅助热源是可行的。     

新型集热蓄热被动式太阳房

介绍了一种用蓄热材料建成的南向集热蓄热被动式太阳房结构和和特性,利用平板式空气太阳能集热器的特性方程分析,得出了室内温度分布的瞬态方程,并分析了该太阳房在沈阳地区24h室温及室内壁温的平均波动,根据计算,该太阳房比传统房节能96％。     

西北新农村建筑太阳能主动供暖试验研究

为了降低西北新农村建筑采暖的能耗,改善室内生活环境,通过试验研究了太阳能主动供暖和传统小型燃煤锅炉供暖的西北新农村建筑的室内热环境、空气质量和采暖能耗的差异。研究结果表明:在室外环境最低温度为-16.2℃条件下,太阳能主动供暖建筑室内平均温度和平均辐射温度分别高出对比建筑5.4℃和3.3℃;在天气晴朗情况下,当室外环境的平均温度高于4.2℃且室外环境的最低温度高于-1.6℃时,仅利用太阳能进行供暖即可满足西北新农村建筑的供暖需求;太阳能主动供暖建筑室内CO,NO2,SO2,CO2及可吸入颗粒物PM10的浓度分别是对比建筑的0.45倍、0.48倍、0.56倍、0.59倍和0.5倍;经过分析得到太阳能主动供暖时室内环境温度与散热片内热水温度以及室外环境温度的二元线性关系;太阳能主动供暖的节能率为86.6%。     

拉萨地区被动太阳能传统民居测试研究

针对拉萨地区某一经过被动太阳能改造典型藏族单层民居,分别在冬、夏季测试了室外气温、太阳辐射强度和不同房间的室内温度.分析测试结果后发现:在拉萨的典型天气条件下(冬季室外平均气温约为0℃,日照时间内太阳总辐射平均强度约为0.45kW/m2),采用大面积南向单玻外窗的被动太阳房室内最低温度与其他房间接近.平均温度和最高温度分别比其他房间提高约3℃和7℃;而被动太阳房在夏季并未出现明显的过热现象.针对该地区被传统民居室内温度整体偏低、被动太阳房室内温度波动大的现状,提出了加强建筑保温和蓄热性能的改造建议.     

严寒地区太阳能-空气源热泵系统供暖实验研究

针对严寒地区所构建的太阳能-空气源热泵系统供暖实验装置,进行热泵独立运行及蓄热水箱-热泵双热源联合运行的供暖特性研究。结果表明:使用空气源热泵单独供暖时,当室外温度低于-12℃时系统COPs达到最低,无法满足室内采暖需求;当室外温度在-12～-7℃之间时,室内采暖需求虽可得到满足,但系统COPs仅为1.10～1.44,节能效果不明显;当室外温度大于-7℃时,室内平均温度可达到20℃以上,系统节能性较好;蓄热水箱的加入会影响运行初期机组的稳定性,但可使室温得到快速提升并提高系统的制热性能,在相同运行条件下,蓄热水箱-热泵混合供暖期间室内平均温度为24.61℃,系统COPs为2.01,较蓄热水箱与空气源热泵交替供暖及单一空气源热泵供暖模式分别提高6.90%、21.08%,供暖效果最佳。     

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.     

Wind power for pumping: The development of the ITP windpump

Water pumping has been one of the main applications for wind power in the past and despite the spread of mains-electric pumps, more than a million windpumps remain in regular use. This paper reviews the general technical and economic requirements for pumping water using wind energy and by way of example gives an overview of the development of the new ITP wind-pump. It then considers the future prospects for this kind of technology.     

Methods of creating solar-reflective nonwhite surfaces and their application to residential roofing materials

We describe methods for creating solar-reflective nonwhite surfaces and their application to a wide variety of residential roofing materials, including metal, clay tile, concrete tile, wood, and asphalt shingle. Reflectance in the near-infrared (NIR) spectrum (0.7–2.5 μm) is maximized by coloring a topcoat with pigments that weakly absorb and (optionally) strongly backscatter NIR radiation, and by adding an NIR-reflective basecoat (e.g., one colored with titanium dioxide rutile white) if both the topcoat and the substrate weakly reflect NIR radiation. Coated steel and glazed clay-tile roofing products achieved NIR reflectances of up to 0.50 and 0.75, respectively, using only cool topcoats. Gray-cement concrete tiles achieved NIR reflectances as high as 0.60 with coatings colored by NIR-scattering pigments. Such tiles could attain NIR reflectances of up to 0.85 by overlaying a white basecoat with a topcoat colored by NIR-transparent organic pigments. Granule-surfaced asphalt shingles achieved NIR reflectances as high as 0.45 when the granules were covered with a white basecoat and a cool color topcoat.     

Thermal decay of an initially hot isothermal water body with application to thermal energy storage

The thermal decay of an initially hot isothermal water body contained in a tank was studied. Analytical solutions (including a group-theoretic solution) were obtained for the one-dimensional heat conduction equation with heat loss from the sides of the tank. The convective heat transfer coefficient was assumed not to be constant over the surface of the tank but to vary with space and time. A very good agreement was obtained between the group-theoretic solution and a numerical solution using the Crank-Nicholson finite difference scheme. The analytical results are discussed in terms of the underlying physical mechanisms.     

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.     

秸秆燃烧中温度对钾转化与释放的影响

通过对稻秆原料进行常规特性分析和EDX元素含量分析,发现钾在稻秆无机元素中占有重要地位。参考原料化学分馏法和土壤中钾的分类与测试方法,给出了对生物质原料及其燃烧产物中钾的定性与定量简易方法。通过程序控温型固定床对稻秆先进行缓慢氧化,然后以100℃为间隔从400～900℃进行成灰,并分别测试其成灰率、有效钾和全钾的份额。结合稻秆原料及其灰中钾的份额分析,进行了稻秆灰中有效钾转化与释放的计算,发现有效钾在700～800℃之间有快速的释放和形态转变。稻秆灰的XRD分析结果表明秸秆灰中钾主要以KCl、K_2SO_4形式存在,得到了钾以盐的形式进行转化与释放的机理。该文中燃烧温度对钾转化与释放的影响规律对设计秸秆电厂时的炉型选择和燃烧参数确定有一定参考价值。