活塞式内燃机燃用沼气的研究

简要介绍了沼气的产生、成分、物理化学性能以及活塞式内燃机燃用沼气可能发生的燃烧速度慢、后燃严重、排气温度高与热负荷大等问题，提出了掺烧和快速全烧两大措施；并相应研制出沼气-柴油双燃料发动机和火花点火全沼气发动机发电机组来适应这两种燃烧方式，取得了较好效果。最后提出将沼气提纯、加压，使其性能接近压缩天然气来作为汽车燃料的方案。     

沼气肥养鱼一举两得

浙江省嘉善县农村能源办公室进行了用沼气肥养鱼的试验。试验用鸭粪投入沼气池发酵产气,用于照明和炊事用气,沼气肥自动流入鱼塘用于养鱼,这样做一方面节约了照明用电,消除了因夜间停电鸭棚无灯光鸭惊影响产蛋的不良因素;另一方面用沼气肥养鱼可提高产量降低成本。     

户用沼气系统运行效果的技术评价指标体系

用层次分析法构建了户用沼气系统的技术评价指标体系,通过德尔菲法构建了评价指标的判定方法学,从而为评价户用沼气系统的运行效果提供理论依据和技术支撑。将户用沼气系统分为5个子系统:构筑物系统、产气系统、沼气输送系统、沼气利用系统、沼液沼渣处理系统。将此评价体系用于评估某国户用沼气系统的运行效果,结果表明,如果仅以正常产气衡量,则正常运行的概率为76%;如果综合考虑沼气系统各个方面,则运行良好的概率仅为1%。     

联合节能技术的研究及现场应用

在对马五中转站锅炉燃气替代燃油的可行性进行详细分析的基础上,对韦庄接转站和马五中转站的集输流程及设备进行联合改造,将原油非密闭输送改为密闭输送方式,实现了马五中转站锅炉停油烧气的目标,经济效益和社会效益显著。     

污水处理场除臭系统的密闭与输送设计

近年来,国内各类污水处理厂陆续增设除臭系统,并收到良好效果,但人们对除臭工艺的重视一般高于收集系统,尤其是密闭和输送,因此除臭系统的密闭和输送就成为了制约整体除臭工艺发挥效能的关键因素。除臭系统的密闭和输送包括密闭装置、抽风口、进风口、输送管道、调节阀门以及风机等。密闭收集装置选型时要选择密闭程度高的密闭形式、并控制好密闭空间,根据臭气源的特点采取不同的收集方式。密闭效果好,采用单点或少点抽风口设计,密闭效果不好,采用多点抽风口设计,以确保密闭装置内气流组织均匀。依据设计的基本原则,输送管道要求主风管尽量位于负荷中心,各支风管的风量、长度相差不大。目前污水处理场除臭系统常用风机的安装方式有两种:密效果好,风机安装在除臭装置之前;密封效果不好,风机安装在除臭装置之后。污水处理厂常用的通风机分为离心式和轴流式,按以往工程项目经验,系统压力至多选到离心风机的中压区。     

±800kV换流变压器局部放电试验研究

在我国当前的电力工程中,特高压换流变压器凭借着超大的输送容量、较远的送电距离、先进的技术水平以及较高的电压等级,成为电力工程中重要的组成部分。特高压换流变压器的局部放电加压试验的质量至关重要,不仅要应对复杂的现场环境,还要具备强大的抗干扰能力。在试验的过程中,想要保证试验的准确性和顺利进行,就要严格地对试验方式进行约束。就特高压换流变压器的局部放电加压方法进行了研究,重点分析了如何加压流程、加压方法、试验设备和安全防护措施以及常用的干扰识别技术,旨在为相关领域试验提供参考。     

综采工作面矸石充填开采技术研究与现场应用

针对雄山五矿“三下”压煤量巨大、综合效益不高等问题,提出了综采工作面矸石充填及密闭挡墙支护技术,并在现场进行了试验。试验结果表明：模袋式快速成型密闭挡墙在经济效益、施工速度和运输车辆占用方面均优于传统的砖砌挡墙,每堵墙可节省资金8 128.55元,提高施工速度33%,材料运输改矿车运输与管道输送,提高了效率,降低了劳动强度。     

沼气在烤制工艺上的应用

沼气在烤制工艺上的应用平谷县农村能源办公室王宝财北京市新能源开发服务公司周静茹平谷县金海艺术品公司赵永才玻璃料器烤花是我国传统的民间工艺之一，基本是灯火烤制．１９９２年，我们考察了北京金海艺术品公司的生产．其生产方式是：双管煤油灯加适量气泵供气，烤制...     

沼气池沉渣可栽培蘑菇

沼气池沉渣,是人畜粪便,杂草秸秆等有机物质在密闭的沼气池内,经厌氧发酵产沼气的剩余物。用于栽培蘑菇可比常规的牛粪干增产10％～15％。其操作方法是:1.出沉渣:在种植蘑菇进行堆料前20天,即9月上旬,将沼气池内的结壳层,沉渣全部捞起,留下清液,出料前5天应停止向池内投     

冷凝水回收系统的改造及效益分析

本文针对离心水泵输送高温冷凝水时存在的汽蚀问题，提出了高温冷凝水的防汽蚀密闭回收方案，并对高温冷凝水的防汽蚀密闭回收产生的经济效益进行了分析。     

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.     

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。     

Exergetic analysis of solid oxide fuel cell and biomass gasification integration with heat pipes

This paper presents an exergetic analysis of a combined heat and power (CHP) system, integrating a near-atmospheric solid oxide fuel cell (SOFC) with an allothermal biomass fluidised bed steam gasification process. The gasification heat requirement is supplied to the fluidised bed from the SOFC stack through high-temperature sodium heat pipes. The CHP system was modelled in AspenPlus™ software including sub-models for the gasification, SOFC, gas cleaning and heat pipes. For an average current density of 3000 A m⁻² the proposed system would consume 90 kg h⁻¹ biomass producing 170 kW_e net power with a system exergetic efficiency of 36%, out of which 34% are electrical.