液相生化法烟气脱硫的研究--微生物的培养及脱硫实验

首先进行了脱硫微生物的培养以及粉煤灰上清液的制备.通过正交实验获得了粉煤灰的最佳浸泡条件,以获得最大浓度的Fe3+离子.并在内径为65mm,高1 500mm的有机玻璃实验台上进行了冷态脱硫实验,研究了不同吸收液、pH值、气液比对脱硫效率的影响.结果显示,在相同的条件下,粉煤灰上清液的脱硫效率高于蒸馏水;加入Fe3+的吸收液脱硫效率高于粉煤灰上清液;加入Fe3+,同时加微生物DYB1脱硫效率最高.气液比相同时,加入微生物DYB1的Fe3+溶液脱硫效率最高.     

循环流化床锅炉烟气脱硫技术研究与应用

正我国最新颁布的《火电厂大气污染物排放标准》(GB13223-2011)中规定,新建锅炉SO2最高允许排放浓度为100mg/m3,现有锅炉SO2最高允许排放浓度为200mg/m3。因此加大燃煤电厂SO2的控制力度就显得非常紧迫和必要。1脱硫技术发展现状截止目前,已开发出200多种SO2控制技术。这些技术按脱硫控制途径可分为:燃烧前脱硫(如洗煤、微生物脱硫);燃     

液相生化法烟气脱硫的研究--原理及前景

概述生物法脱硫的历史及现状以及微生物法脱硫和过渡金属Fe3+/Fe2+的催化氧化脱硫机理,提出了液相生化法烟气脱硫的崭新构想,即合理地把微生物代谢和Fe3+催化氧化脱硫结合起来,可以有效地降低SO2的排放量.     

沼气微氧发酵过程硫转化及微生物群落

以水稻秸秆与猪粪为原料,探究微氧发酵过程中S元素的转化与微生物群落特征以及通氧量的影响。结果表明,厌氧发酵过程中原料的S元素约有65.7%转化为H2S进入沼气,19.0%进入发酵后的沼液,15.3%残留在沼渣中。微氧条件下,沼液中S2-的浓度(100 mg/L)远低于厌氧条件的250 mg/L,约71.8%的S元素转化为H2S然后被氧化成为S单质和少量SO42-。H2S去除效率随通氧量的增大而增大,当通氧量为11.85 L/m3沼气时,约96%的H2S被氧化脱除。根据高通量测序结果,与厌氧发酵相比,在微氧条件下,沼液中微生物多样性仅有轻微变化,比较稳定;硫氧化菌明显增多,而产甲烷菌无明显变化。较高浓度硫氧化菌的存在,有利于沼气中H2S的及时转化,可减轻H2S对产甲烷菌活性的抑制,从而促进厌氧发酵的进行。     

自养微生物反硝化法去除沼气中H2S工艺研究

通过将营口污水处理厂二沉池的泥水混合物进行静置沉淀,取上清液进行稀释筛选得到一株革兰氏阴性菌D-12。然后采用生物反应器内的营养液(Na OH+驯化液)对沼气中的H_2S进行洗脱,再采用筛选菌株D-12对含有H_2S的营养液进行反硝化脱硫(试验周期为38 d)。以初始S~(2-)浓度、微生物添加量和NO_3~-浓度为自变量,以降解试验中的S~(2-)去除率为因变量,采用响应曲面法Box-Behnken设计实验,研究各自变量及其交互作用对S~(2-)去除率的影响,并得到二次多项式回归方程预测模型。研究结果表明:NO_3~-在反应体系中可以作为有效电子受体,促进微生物将S~(2-)氧化为单质硫;优化后的试验条件为S~(2-)浓度为1 258.61 mg/L,NO_3~-浓度为843.96mg/L,微生物添加量为219.96 mg/L,此时S~(2-)去除率为98.38%,与S~(2-)预测去除率的相对误差为1.62%。     

船舶尾气臭氧氧化-海水吸收的脱硫脱硝新工艺研究

通过模拟试验研究了臭氧氧化结合海水吸收同时脱除船用发动机排气中SO2和NO2的新工艺.在管式反应器内研究了反应温度、n(O3)/n(NO)(物质的量之比)、碳氢、SO2等对臭氧氧化NO的影响,并对模拟尾气进行了臭氧氧化结合海水吸收的脱硫脱硝试验.结果表明,n(O3)/n(NO)对臭氧氧化NO影响很大,NO氧化率随n(O3)/n(NO)呈线性增长,n(O3)/n(NO)为1,反应温度分别为常温、150℃和200℃时,NO氧化率分别达到99.0%、98.3%和98.1%;反应温度低于200℃时,温度对臭氧氧化NO影响很小,而当反应温度升至275℃时,NO氧化率明显下降,这与臭氧在较高温度下分解有关;SO2在O3/NO/SO2/N2/O2体系和O3/NO/C2H4/SO2/N2/O2体系中对臭氧氧化NO都没有影响;200℃以下,C2H4对臭氧氧化NO影响很小,而在275 ℃时,C2H4对臭氧氧化NO有一定促进作用;模拟尾气经臭氧氧化-海水吸收后,脱硫率为98.5%,n(O3)/n(NO)为1时的脱硝率为91.05,NO能耗为56.4 g、(kW·h).     

亚硫酸钠循环法烟气脱硫工艺实验研究

以处理量为1800m3/h的亚硫酸钠循环法烟气脱硫装置为实验对象,着重研究吸收液pH值、液气比L/G、吸收液成份和脱硫剂初始浓度等因素对脱硫效率的影响,并对脱硫剂再生过程和再生清液的脱硫特性进行研究。结果表明:吸收液pH值决定硫成份在溶液中的状态,从而影响脱硫效率,当pH>6时,脱硫效率高且随pH增大变化平缓;当pH<6时,脱硫效率随pH减少急剧降低;该工艺可以在较低的液气比(L/G=0.25~1.25L/m3)下保持较高的脱硫效率(η>90%);同等条件下,与NaOH和Na2CO3相比较,Na2SO3的脱硫能力稍低;吸收液Na2SO3浓度在5%~10%范围内脱硫效率大于90%;脱硫剂再生反应过程能很快完成,再生脱硫剂脱硫效率稳定,与新鲜脱硫剂相比脱硫效率略低。     

氧化亚铁硫杆菌烟气脱硫实验研究

研究利用氧化亚铁硫杆菌和Fe离子协同脱除烟气中的SO2,考察了液气比、反应温度、初始Fe2＋浓度等因素对脱硫率的影响。研究表明氧化亚铁硫杆菌和Fe3＋体系对SO2具有循环催化氧化吸收的作用,并且提高初始Fe2＋浓度,保持适宜的温度（30～40℃）,有利于维持此循环效果而得到持久高效的脱硫率。     

海水烟气脱硫技术及其在电站上的工程应用

利用纯海水呈弱碱性且具有吸收酸性气体的天然特点,开发了海水烟气脱硫(SWFGD)技术.SO2采用钢制喷淋空塔高效吸收,吸收塔酸性海水以重力流方式排出,吸收塔海水输送采用母管制与单元制相结合的方式,脱硫海水水质恢复系统采用以曝气池中层曝气为主和/或吸收塔海水池曝气为辅的措施.该技术在300 MW机组的电站工程运行结果表明:烟气SO2浓度在1300~1700 mg/m3工况下,脱硫效率>95%,脱硫排放海水PH值>6.8,饱和溶解氧(DO)>5 mg/L,化学需氧量(COD)增量<0.20 mg/L.     

长三角燃煤电厂烟气脱硫对二氧化硫污染的改善效果

结合2004年长三角地区燃煤电厂SO2排放清单以及"十一五"期间的脱硫计划,测算了2010年长三角地区燃煤电厂的SO2排放量,并利用美国CALUFF模型模拟了脱硫前后大气中SO2的年均浓度变化.研究结果表明,到2010年长三角地区SO2排放总量将从2004年的1 850 kt下降到1 430 kt,其中燃煤电厂的排放量将从2004年的1 260 kt下降到840 kt;电厂排放在长三角地区造成的SO2年均浓度将从11.1μg/m3下降到9.9μg/m3,下降比例达11%,受益城市广泛,环境改善效果明显,其中上海和宁波削减量最大,受益亦最大.     

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。