基于TRIZ的冲击剪切式秸秆微粉机概念设计

农作物秸秆微粉碎后可实现高品质精细化利用,文章基于发明问题解决理论（TRIZ）进行了秸秆微粉机的概念设计,提出了多层动定刀冲击、剪切、摩擦的复合粉碎方式,应用系统功能分析、物场分析、技术矛盾、物理矛盾、最终理想解、聪明小人法、功能导向搜索等TRIZ工具对秸秆微粉机的粉碎机构、喂入机构和分离收集机构进行创新设计,研究成果为提高秸秆微粉碎效率和降低粉碎粒度提供了参考。     

基于TRIZ的秸秆皮穰分离机概念设计

文章以提高秸秆皮穰分离效率,实现皮、穰、叶分类收集且不破坏秸秆强度为目标,基于发明问题解决理论(TRIZ)进行秸秆皮穰分离机设计,提出了去除秸秆叶-切开秸秆皮-刮除秸秆穰-分类收集的作业方式,并应用最终理想解、系统功能分析、物场分析、发明原理、功能裁剪、进化法则、功能导向搜索、金鱼法等TRIZ工具分别对喂入机构、除叶机构、定位机构、切割结构、夹持机构、去穰机构、收集机构进行创新设计。在产品概念设计阶段应用TRIZ理论,可以克服传统经验、类比设计的局限,提升设计效率和设计质量。     

TRIZ创新方法在EGR阀布置设计中的应用

基于TRIZ创新方法,分析废气再循环(EGR)阀布置中面临的矛盾和问题,并进行概念设计。在EGR布置概念设计完成后,进行概念设计验证,确认EGR阀布置设计的开发结果。     

风光储互补微网系统集成技术的研究与设计

为提高微电网的运行效率,从系统层面统一协调控制各分布式电源及负荷,提出了基于风光储互补的微网系统的集成技术。介绍了基于风光储互补的微网系统方案,提出了微网运行模式和微网离网、并网以及离并网切换的协调控制策略,设计了基于DSP 28335芯片的能量协调控制器,实现了风光储微网系统控制管理功能的集成。工程实践验证了该设计方案的有效性。     

基于数据库的共轨系统正向设计开发

介绍了基于产品结构、产品开发过程和学科领域3个维度的共轨知识数据库的建立方法和主要建立过程,为积累共轨系统的知识和提高共轨零部件开发效率提供了有效的方法手段,从实例出发介绍了共轨产品结构数据库分类、主要产品正向开发阶段和共轨相关学科领域的分类方法,对如何应用这种数据库为共轨系统正向设计开发提供支持进行了分阶段阐述,对优劣势分析(SWOT)、质量功能展开(QFD)、失效风险分析(FEMA)、工作分解结构(WBS)和发明问题的解决理论(TRIZ)等工具在共轨产品开发过程中的应用进行了实例分析。     

TRIZ在生物质平模成型机安全设计中应用

应用TRIZ对传统生物质平模成型机中存在的工作效率低,工作性能不稳定,安全性低等问题进行分析,建立矛盾矩阵,对矛盾矩阵进行求解。首先对平模成型机的机构及工作原理做了简单介绍,分析了目前存在的不安全因素及影响工作效率的因素。针对存在的问题,以人机工程学原理为基础,以低功耗、高效率、高安全可靠性为目标,对生物质平模成型机进行安全设计。提出了设计方案,以提高设计效率和安全性,具有极大的实用价值。     

材料和喷口直径对多孔介质微燃烧的影响

为了进一步优化微燃烧室的设计,以最大化提高微燃烧室的能量转换效率及微热光电系统的整体工作效率,在前期工作的基础上设计了不同多孔介质材料及喷嘴/燃烧室内径比的多孔介质微燃烧室.通过实验验证,针对多孔介质微燃烧室内的氢氧预混燃烧进行了数值模拟计算,研究结果表明,多孔介质材料,喷嘴/燃烧室内径比对微燃烧室内的微尺度燃烧有重要影响,微燃烧室在多孔介质材料为SiC, 喷嘴/燃烧室内径比为0.27时燃烧效率最高,有利于提高微热光电系统的整体效率.     

超微玉米秸秆的沉降稳定性及产氢能力研究

以红螺菌科光合细菌为实验菌种,以超微玉米秸秆为产氢底物,研究超微玉米秸秆的沉降稳定性及产氢能力,结果表明超微粉碎时间越长,颗粒度越小,超微玉米秸秆的比重和沉降速度越大,且超微粉碎技术可增大光合细菌和玉米秸秆的接触面积,提高光合细菌的产氢能力,但粉碎粒度太小,超微秸秆内部具有较强的凝聚作用,玉米秸秆的稳定性降低,超微玉米秸秆沉积于反应器底部,难以及时被分解利用,最佳粉碎时间60~80 min。     

基于TRIZ理论的机油盘改进设计研究

针对某四驱乘用车主减速器输出轴贯穿机油盘的特殊布置需求,分析整车发动机舱的布置空间限制、主减速器输出轴孔及机油盘出模空间之间的矛盾,基于TRIZ理论进行矛盾分析,找出推荐解,根据推荐解制定了备选技术方案,并最终寻找出最优方案,结论表明,基于TRIZ理论改进设计的机油盘具有结构简单、轻质、铸造工艺性优异的特点,TRIZ理论对零部件的结构设计优化具有指导意义。     

基于Android的户用微网EMS客户端软件

户用微网EMS（能量管理系统）主要是针对小型的、单用户的微电网系统。结合户用微网的特性,软件主要监控分布式电源、负载和储能单元的实时运行数据,综合分析各单元发用电数据,同时协调与控制各单元的工作。采用基于集操作系统、中间件和关键应用为一体的Android系统所设计的智能手机软件平台,改变了传统的微网EMS基于B／S结构设计,采用标准的JavaEE平台进行开发的特点,克服了必须有独立的PC机来支持运行和访问的弊端。建立了户用微网能量管理系统客户端软件的基础功能模型。总结了便携式终端设备可随时方便灵活地进行数据访问和远程控制的特点,提出了智能户用微网业务管理的新方法和建议。     

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%.     

Performance assessment of some ice TES systems

In this paper, a performance assessment of four main types of ice storage techniques for space cooling purposes, namely ice slurry systems, ice-on-coil systems (both internal and external melt), and encapsulated ice systems is conducted. A detailed analysis, coupled with a case study based on the literature data, follows. The ice making techniques are compared on the basis of energy and exergy performance criteria including charging, discharging and storage efficiencies, which make up the ice storage and retrieval process. Losses due to heat leakage and irreversibilities from entropy generation are included. A vapor-compression refrigeration cycle with R134a as the working fluid provides the cooling load, while the analysis is performed in both a full storage and partial storage process, with comparisons between these two. In the case of full storage, the energy efficiencies associated with the charging and discharging processes are well over 98% in all cases, while the exergy efficiencies ranged from 46% to 76% for the charging cycle and 18% to 24% for the discharging cycle. For the partial storage systems, all energy and exergy efficiencies were slightly less than that for full storage, due to the increasing effect wall heat leakage has on the decreased storage volume and load. The results show that energy analyses alone do not provide much useful insight into system behavior, since the vast majority of losses in all processes are a result of entropy generation which results from system irreversibilities.     

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.     

Effect of co-cultivation of Chlamydomonas reinhardtii with Azotobacter chroococcum on hydrogen production

Chlamydomonas reinhardtii cc124 and Azotobacter chroococcum bacteria were co-cultured with a series of volume ratios and under a variety of light densities to determine the optimal culture conditions and to investigate the mechanism by which co-cultivation improves H₂ yield. The results demonstrated that the optimal culture conditions for the highest H₂ production of the combined system were a 1:40 vol ratio of bacterial cultures to algal cultures under 200 μE m^?2 s^?1. Under these conditions, the maximal H₂ yield was 255 μmol mg^?1 Chl, which was approximately 15.9-fold of the control. The reasons for the improvement in H₂ yield included decreased O₂ content, enhanced algal growth, and increased H₂ase activity and starch content of the combined system.     

Natural-gas fueled spark-ignition (SI) and compression-ignition (CI) engine performance and emissions

Natural gas is a fossil fuel that has been used and investigated extensively for use in spark-ignition (SI) and compression-ignition (CI) engines. Compared with conventional gasoline engines, SI engines using natural gas can run at higher compression ratios, thus producing higher thermal efficiencies but also increased nitrogen oxide (NO_x) emissions, while producing lower emissions of carbon dioxide (CO₂), unburned hydrocarbons (HC) and carbon monoxide (CO). These engines also produce relatively less power than gasoline-fueled engines because of the convergence of one or more of three factors: a reduction in volumetric efficiency due to natural-gas injection in the intake manifold; the lower stoichiometric fuel/air ratio of natural gas compared to gasoline; and the lower equivalence ratio at which these engines may be run in order to reduce NO_x emissions. High NO_x emissions, especially at high loads, reduce with exhaust gas recirculation (EGR). However, EGR rates above a maximum value result in misfire and erratic engine operation. Hydrogen gas addition increases this EGR threshold significantly. In addition, hydrogen increases the flame speed of the natural gas-hydrogen mixture. Power levels can be increased with supercharging or turbocharging and intercooling. Natural gas is used to power CI engines via the dual-fuel mode, where a high-cetane fuel is injected along with the natural gas in order to provide a source of ignition for the charge. Thermal efficiency levels compared with normal diesel-fueled CI-engine operation are generally maintained with dual-fuel operation, and smoke levels are reduced significantly. At the same time, lower NO_x and CO₂ emissions, as well as higher HC and CO emissions compared with normal CI-engine operation at low and intermediate loads are recorded. These trends are caused by the low charge temperature and increased ignition delay, resulting in low combustion temperatures. Another factor is insufficient penetration and distribution of the pilot fuel in the charge, resulting in a lack of ignition centers. EGR admission at low and intermediate loads increases combustion temperatures, lowering unburned HC and CO emissions. Larger pilot fuel quantities at these load levels and hydrogen gas addition can also help increase combustion efficiency. Power output is lower at certain conditions than diesel-fueled engines, for reasons similar to those affecting power output of SI engines. In both cases the power output can be maintained with direct injection. Overall, natural gas can be used in both engine types; however further refinement and optimization of engines and fuel-injection systems is needed.     

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.     

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.     

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。