以挖掘数据替代测点失效值的热力系统性能研究

为解决机组热力系统测点参数失效致使其性能计算模型不能作出正常评估的问题,基于相似性原理,利用某600MW机组热力系统历史正常运行数据建立了其动态超球预测模型,获得了该机组热力系统性能计算模型所需的预测值及相似度曲线,验证了性能计算模型预测值的可靠性,并以测点预测值作为挖掘数据替换其失效值.结果表明:合理选择和适当补入历史正常运行数据,可降低预测值的相对误差,并将其控制在工程允许范围内,提高其替代失效值的可靠性;当输入的热力系统测点参数因测量系统等引起随机波动甚至个别参数失效时,该方法仍可实现对机组热力系统运行性能的正常实时评估和故障诊断.     

火电机组一次调频性能实时监测系统

为了实时监测和评价火电机组一次调频性能,开发了火电机组一次调频性能实测监测系统。该系统具有一次调频参数异动感知、一次调频性能量化预测及自适应校正等关键功能。某机组的实际应用表明,该系统能够实现火电机组一次调频关键参数的实时监测和调频性能的准确预测。     

风电机组塔筒在线监测技术的应用研究

以塔筒形态在线监测系统的研究为切入点,将倾斜传感器和加速度传感器的数据代入塔体变形的参数方程式,通过方程求解、现场工程实践等方法较准确地得到塔体的变形数据。该系统可以广泛应用于风电机组塔体等高塔的倾斜及变形测量,实现在线安全监控。     

350MW汽轮发电机组性能监测系统

】针对３５０ＭＷ汽轮发电机组的热力性能介绍了一种性能监测系统,该系统选用常规测点作为机组性能监测的基本数据,采用了易于评价机组性能和指导运行调整的性能分析方法。现场运行情况表明,整个系统的设计和实施是合理的,对指导现场的机组运行发挥了重要作用。     

基于非线性模型的燃气轮机热参数故障诊断及仿真

燃气轮机气动部件故障的发生会导致机组性能参数的变化,且为复杂的非线性变化。在建立燃气轮机标准模型的基础上,研究了系统的故障性能参数的变化及建立了系统的故障模型。首先通过标准模型仿真数据和机组故障运行数据的对比分析,初步定位机组的故障部件,进而提出了修正部件特征性能参数的方法,通过模块实现机组故障的非线性表达,在EASY5仿真平台上建立了燃气轮机系统的故障模型。利用该模型可通过机组非线性模型定量表达部件性能参数的变化,准确地实现机组的故障定位和仿真。以某联合循环机组的燃气轮机为例对此方法进行了验证,实现了机组故障工况的重现,为机组性能特性研究、故障诊断和故障分析奠定了一定的基础。     

大型汽轮发电机组轴系扭振响应在线监测仿真计算的研究

大型汽轮发电机组扭转振动的在线监测系统可以连续监测机组的部分电气和蒸汽参数，机端测点的扭角等，并在某些参数的变化超标时采集数据和报警同时启动上位计算机，实时分析该时刻机组的扭振情况及其引起扔疲劳寿命损耗。着重讨论了利用实测数据和轴系结构模型，快速计算轴系各危险截面扭振响应的方法，并给出了利用该方法计算的部分实测扭振响应的曲线。     

基于性能仿真模型的燃驱压缩机组数据调和的方法及应用

由于测量误差的存在,测量参数不能正确反映燃驱压缩机组的真实状态,而用数据调和方法来降低测量误差提高数据的准确度又常面临着缺少冗余度的问题。本文提出一种基于性能仿真模型的数据调和新方法,通过建立机组仿真模型,建立监测参数之间的相互关系,以增加系统的解析冗余度,结果表明其有提高数据准确度的作用;分析影响数据调和质量的各种因素,得出压气机出口温度、燃料量、动力涡轮和高压涡轮出口温度等因素对数据调和质量影响较大。     

50 MW背压机组冷态启动的暖缸状态实时监测方法

为满足对机组冷态启动时暖缸状态进行实时、全方位监测的需求,提出了一种暖机状态的实时监测方法:首先,通过对机组进行三维建模及热应力分析,获取可充分表征整个缸体温度场的温度测点;然后,在原有DCS蒸汽测点参数的基础上,加入新的缸体局部温度测点;最后,开发了暖缸状态实时监测系统,利用上述温度测点数据对暖缸状态进行可视化,让工作人员可直观判断暖机效果。这既改善了机组整体运行安全系数,避免因暖缸不充分带来的轴振超限(甚至碰摩)等安全问题,又提高了暖机效率,避免因长时间暖机带来大量蒸汽的消耗及对机组并网发电的影响,提高机组整体运行经济性,此外,该方法具有普适性,具有较高推广价值。     

相似规则建模方法在火电机组设备状态监测中的应用研究

以火电机组的主要设备为研究对象,研究按相似性规则建模的方法在设备状态监测中的应用。针对火电机组存储数据的高维、体量大等特征,引入K均值聚类方法提取设备运行的典型工况,结合设备的具体参数模型构建出其相似性规则模型中的动态矩阵,进而可以对设备参数值进行实时估计。利用国内某600 MW机组的实际运行数据,选取给水泵和高压加热器两种典型的主要设备对相似性规则的建模过程进行阐述,实际运行数据的计算结果表明,方法能够对设备参数值进行实时的准确估计,仿真结果还进一步表明,在测点故障和异常工况下,该方法能够及时发现并给出预警。     

火电机组节能减排在线监测系统的研究与应用

介绍了火电机组节能减排在线监测系统的研究与应用。利用节能减排在线监管系统实现火电机组污染物减排的实时监控,为火电厂污染物运行优化提供参考。系统基于火电厂生产实时数据采集、数据压缩存储原理、数据校验,按有关标准进行能耗和污染物指标的在线计算。实现机组的煤耗分析排序和污染指标的统计分析,为机组节能减排提供基础数据,同时展示生产数据及分析指标,报表系统实现分析指标的统计。通过实际比较,系统计算准确,监测内容全面,满足分析和统计要求。     

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。