A/O膜生物反应器处理炼油污水试验研究

通过A/O膜生物反应器处理炼油污水模型试验,研究A/O膜生物反应器去除炼油污水氨氮的可行性。结果表明,A/O膜生物反应器能有效去除炼油污水中氨氮。氨氮(NH3-N)和CODcr容积负荷分别在0.04～0.08kg/m3.d范围内和0.30～0.84kg/m3.d范围内时,出水中NH3-N浓度小于5mg/L;NH3-N及CODcr达标排放。     

C/N值对A/O生物滤池性能影响分析

通过分析C/N值对A/O生物滤池性能的影响,为污水回用提供有效的处理工艺及参数。对模拟污水进行动态试验,研究不同的C/N比值对氨氮、总氮及COD去除效果的影响。试验表明,在当A/O生物滤池C/N比值为4.6~5.5、水力负荷为2~3m/h,回流比为1∶2,好氧段气水比为1∶3时,原水中的NH3-N、TN和COD都得到了较好的去除,去除率最高分别能达到92.1%,92%,95%。A/O生物滤池能够有效地去除污水中的氨氮、总氮及COD等,在适当的C/N比值的情况下,可有效提高去除效率,降低运行成本。     

复合人工湿地对大连地区污染河水的净化效果

为研究大连地区复合人工湿地对污染河水的净化效果,在大连复州河河滩上构建了4种不同组合的复合人工湿地。一年多的试验结果表明,组合1对COD、NH+4-N、TP的去除效果优于其他组合,对应平均去除率分别为46%、35%、28%;4种组合对TN去除效率差别不大,平均去除率为18%~20%;温度与TN和NH+4-N去除率之间呈正相关,其变化对两者去除效果影响较大;水力负荷对人工湿地的COD、NH+4-N、TP去除效果有较大影响,适当的水力负荷能保证人工湿地系统好的处理效果。     

IC反应器处理低浓度有机废水的启动实验研究

对内循环厌氧反应器(IC反应器)在(33±O.5)℃下处理低浓度有机废水的启动特性进行了实验研究.结果表明:反应器经过59 d启动成功:当进水COD浓度为411.6 mg/L,HRT为0.8 h.相应的有机负荷COD为12.3 kg/(m3·d)时,其COD去除率能稳定在87%左右,日产气率15 m3/(m3·d)左右,出水VFA浓度HAc为41.2～43.6 mg/L;污泥床反应区COD去除量占总COD去除量的77%以上,远大于精细处理区;启动完成后,反应器底部形成了颗粒污泥,镜检发现颗粒污泥表面分布着丝状菌,内部则以杆菌和球菌为主.     

后置反硝化滤池脱氮除磷技术研究

针对沙营污水厂提标改造,研制了反硝化生物滤池工艺中试装置,对污水厂现状出水进行深度处理,经中试试验研究,工艺对COD、TN、TP的去除效果较好,出水能达到国标一级A标准。同时试验得出:较高的水力负荷,有利于提高脱氮速率,控制适宜的C/B对后置反硝化滤池运行非常重要。     

循环载体生物膜SBR反应器处理生活污水实验研究

采用中试规模,利用循环栽体生物膜SBR反应器处理某高校生活污水,实验结果表明:在反应时间4小时,容积负荷1.24～1.48kg CODm-3·d-1,转笼转速2min/r时,系统时COD、SS、NH3-N、TN、TP去除率分别达到90.4%、89.4%、87.5%、75.3%、83.2%,出水COD、SS、NH3-N、TN、TP分别为33mg/L、13.5 mg/L、7.6 mg/L、13.5 mg/L、0.55 mg/L.     

中低温下ABR-HCW处理农村生活污水的效能研究

在中低温条件下,研究了ABR(厌氧折流板反应器)-HCW(复合人工湿地)组合工艺对农村生活污水的处理效果。结果表明:当ABR(厌氧折流板反应器)的HRT(水力停留时间)约为5h(HCW的HLR(水力负荷)约为1.2m/d),温度为15～25℃和5～15℃时,系统对COD(化学需氧量)、NH4+-N(氨氮)和TP(总磷)平均去除率分别为90%、74%、76%和82%、61%、86%。此外,通过增加HCW(复合人工湿地)的HRT(水力停留时间)以增强系统的脱氮能力,其效果并不明显。     

进水水力负荷对植被浅沟雨水径流控制效果的影响

为揭示植被浅沟对雨水径流的控制效果,通过实验室尺度模拟试验,分析不同进水水力负荷条件下植被浅沟对雨水径流水文特征的影响。结果表明,当进水水力负荷为1～4 m3/h、进水时间为30min时,植被浅沟对雨水径流峰值和径流总量的削减率分别为4.54%～13.49%、10.32%～35.38%,对应的削减量分别为0.14～0.18m3/h、0.18～0.21m3,径流峰现延后时间则介于9.40～20.37min;随进水水力负荷的减小,植被浅沟对雨水径流峰值和径流总量的控制效果呈上升趋势,径流峰现延后时间也随之增大;采取减小水力负荷(或增大浅沟断面尺寸)的方式,从削减量指标判断,对提升植被浅沟的雨水径流峰值控制和总量控制效果意义不大;因径流峰值延后时间的增大而产生的良好削峰和错峰效果,可有效缓解雨水排放系统的行洪压力。     

连续流生物制氢反应器中有机负荷对产氢的影响

采用连续流搅拌槽式反应系统(CSTR)作为反应装置,以红糖水为发酵底物,污水处理厂剩余污泥为反应的启动污泥,在进水p H值为7.0±0.1、氧化还原电位(ORP)为-420 m V、温度(35±1)℃、水力停留时间(HRT)为6 h等影响因子调控下,达到稳定产氢(主要为乙醇型发酵)。在其他参数不变的条件下,通过改变有机负荷,着重研究其对产氢能力的影响,同时调节p H值使微生物保持较高活性。结果表明,当有机负荷从12 kg/(m3·d)上升为32 kg/(m3·d)时,产气和产氢速率均有持续增大的趋势。当有机负荷为32 kg/(m3·d)时,达最大产气速率(18.6 L/d),产氢速率为6.4 L/d,较初始有机负荷12 kg/(m3·d)时分别提高89%和87%。在系统运行过程中,进水p H值降低至5.85时,厌氧发酵微生物活性受到抑制,产氢速率有所下降,ORP上升至-328 m V。此时,向反应器内投加一定量的Na OH调节p H值,使反应器保持较高产氢速率的乙醇型发酵类型。     

A/O生物滤池处理生活污水的挂膜启动试验研究

本试验中,A/O生物滤池挂膜启动分为两个阶段进行:第一阶段,好氧柱利用活性污泥接种后循环曝气培养生物膜;第二阶段,缺氧柱通入待处理的水及从挂膜完成后好氧柱回流的水,并逐步提高滤速启动,进行缺氧微生物的培养和驯化。本试验二级好氧滤柱采用沈阳北部污水处理厂回流污泥接种,以待处理的原水启动挂膜。试验结果表明,当滤速8.8L/h(2m/h)小流量进水,回流比1:1,二级好氧柱曝气量25L/h时,在25天内,能在填料表面形成较稳定的生物膜,出水COD、NH3-N及浊度能分别稳定到12mg/L、5.22mg/L及10NTU以下。     

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%.     

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。     

Contents in Volume 23,2014

<正>~~     

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.     

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.