写在新财年到来时——2009，MI为你支招拼经济

自从那复杂的“次贷危机”开了头,金融海啸也跟着来了,中国GDP指数从两位数跌到个位数了,企业倒闭了,某某又被裁员了……面对这场“浩劫”,考验企业们的“抵抗力”的时候到了,而除了防守外,企业经营者们更应该主动出击。     

1341材料在循环水泵上的应用

对热电厂发电机的三台循环水泵的运行状况进行了分析,并用BELZONA1341材料对水泵叶轮的表面进行了处理,减少了叶轮表面与水流的阻力和涡流的产生,降低了电机的有功电流,节约了电能,并且延长设备的寿命,效果十分明显.     

750 kV两站两线科研项目管理

针对兰州超高压输变电公司科研项目管理模式进行了研究与分析,提出了科研项目分解的方案,通过本方案明确了基本课题,可以较为全面、系统指导科研工作的开展,增强了科研项目实施的可操作性。构建了矩阵式科研项目管理组织结构,优化配置了公司各科研资源,明确了科研项目的各主要责任主体。确立了科研项目管理流程,做到闭环控制,加强了科研项目过程管理。     

柴油机缸套三维温度场有限元分析与试验研究

建立了柴油机气缸套数学和几何模型,确定了合理的边界条件,利用MSC有限元分析软件,进行了缸套的温度场三维有限元分析,实测了柴油机的缸套温度,验证了有限元计算的准确性。     

电弧炉工作层耐材砌衬技术改造及其经济效益

阐述了根据生产实际情况,改造了宁夏恒力集团有限公司炼钢分厂18t电弧炉工作层耐材砌衬的材质及砖型,从而降低了工人的劳动强度,提高了工作效率,降低了企业生产成本,提高了经济效益。     

真空除氧冷凝系统技术改进

真空除氧冷凝系统原采用混合式冷凝器,给系统运行带来许多问题,重新设计计算后,系统改用表面式换热器,不但完全达到了原要求的工艺指标,而且,停用了新鲜水,回收了蒸汽的余热,改善了工人的劳动条件,取得了较好的经济效益和社会效益.     

两轮摩托车振动耐久试验台的设计

阐述了摩托车振动耐久试验台的设计方案。方案中描述了两轮摩托车振动耐久试验台的结构组成,详细介绍了系统的关键硬件电路,提出了车速控制策略,给出了车速的实时测量和控制流程图。实验表明,摩托车振动耐久试验台为摩托车的振动耐久检测提供了方便,高效,节能的试验平台。     

蓄热式加热炉燃烧系统的改造

针对轧钢加热炉加热能力不足,自动化控制水平落后的情况,对加热炉进行了改造,更换了单蓄热式空气烧嘴,并对自动控制系统进行了升级改造,从而提高了加热能力和自动控制水平,降低了煤气消耗,取得了良好的经济效益。     

水轮发电机组电气制动的应用实践

大唐石泉水电厂水轮发电机组采用电气制动停机系统,缩短了停机时间,大大改善了机组的停机工况,消除了机械制动时,制动块与制动环因摩擦而引起的机械疲劳,同时洁净了环境,提高了机组控制的自动化水平,为电站"少人值班,无人值守"的发展提供了可能,同时提高了发电机的安全运行水平.     

采用喷射泵疏水方式的回热系统热经济性分析

介绍了目前凝汽式汽轮机组回热系统的基本疏水方式,分析了其优缺点。介绍了喷射泵的工作原理,建立了喷射泵工作流体流量的计算模型。提出了采用喷射泵的回热系统疏水方式,拟定了采用喷射泵疏水方式后机组的原则性回热系统简图。基于常规热平衡法,确定了喷射泵出口混合焓,并建立了机组热经济性指标的计算模型。以某300MW机组为例,计算了喷射泵的喷射系数,并对采用不同疏水方式机组的热经济性进行了比较。结果表明,采用喷射泵疏水方式机组的热经济性明显高于采用逐级自流疏水方式机组的热经济性。     

Comparative studies on Ar and He closed-cycle MHD power plants combined with fossil fuel

Comparative studies on Ar and He closed-cycle MHD power plants combined with fossil fuel are performed. The sizes of a regenerative heat exchanger and a boiler are expected to be smaller for He than for Ar. The pressure loss of a working gas in a regenerative heat exchanger is reduced for He. The purification subsystem for He is expected to be more compact and economical than that for Ar; but a larger compressor is required for He than for Ar.     

太阳电池组件自然通风冷却的数值模拟

建立了光伏建筑一体化系统中太阳电池组件自然通风冷却的理论模型,在运行环境、系统结构变化等情况下利用模型对太阳电池温度进行了数值模拟。模拟结果表明,适宜的环境风速对太阳电池的散热能起到积极效果;0．30m的通风流道宽度在上海地区是BIPV中太阳电池一个合适的安装宽度。     

Damage mechanics based design methodology for tidal current turbine composite blades

A material model based on the Puck phenomenological failure criteria for fibre and inter-fibre failure of glass-fibre and carbon-fibre reinforced polymer composites is presented. The model is applied through a user-defined material subroutine for 3D shell elements. Sub-modelling is used for detailed analysis of the highest stressed regions in the blades. The material model is incorporated into a methodology for the design and analysis of composite tidal current turbine blades. The methodology employs an iterative design process with respect to a number of failure criteria to ensure optimal structural and material performance of the blade. The methodology is automated using the Python programming language to enable efficient variation of model parameters for various design conditions. The forces acting on the blades are determined from blade element momentum theory for a number of turbine operating conditions. The results of a design case study for a typical horizontal axis device are presented to demonstrate the methodology.     

Effect of cellulose and lignin content on pyrolysis and combustion characteristics for several types of biomass

Fundamental pyrolysis and combustion behaviors for several types of biomass are tested by a thermo-gravimetric analyzer. The main compositions of cellulose and lignin contents for several types of biomass are analyzed chemically. Based on the main composition results obtained, the experimental results for the actual biomass samples are compared with those for the simulated biomass, which is made of the mixture of the cellulose with lignin chemical. The morphological changes before and after the reactions are also observed by a scanning electron microscope. The main compositions in the biomass consisted of cellulose and lignin. The cellulose content was more than lignin for the biomass samples selected in this study. The reaction for the actual biomass samples proceeded with the two stages. The first and second stage corresponded to devolatilization and char combustion during combustion, respectively. The first stage showed rapid mass decrease caused by cellulose decomposition. At the second stage, lignin decomposed for pyrolysis and its char burned for combustion. For the biomass with higher cellulose content, the pyrolysis rate became faster. While, the biomass with higher lignin content gave slower pyrolysis rate. The cellulose and lignin content in the biomasses was one of the important parameters to evaluate the pyrolysis characteristics. The combustion characteristics for the actual biomass depends on the char morphology produced.     

Blind-prediction: Estimating the consequences of vented hydrogen deflagrations for homogeneous mixtures in 20-foot ISO containers

This paper summarises the results from a blind-prediction study for consequence models used for estimating the reduced explosion pressure and structural response in vented hydrogen deflagrations. The work is part of the project Improving hydrogen safety for energy applications through pre-normative research on vented deflagrations (HySEA). The scenarios selected for the blind-prediction entailed vented explosions with homogeneous hydrogen-air mixtures in a 20-foot ISO (International Organization for Standardization) container. The test program included two configurations and six experiments, i.e. three repeated tests for each scenario. The comparison between experimental results and model predictions reveals reasonable agreement for some of the models, and significant discrepancies for others. The results from the first blind-prediction study in the HySEA project should motivate developers to improve and validate their models, as well as to update documentation and guidelines for users of the models.     

Disquisition of thermophoresis and chemical reaction sketch in viscous stream over a wedge

A computative exploration is engraved on synchronized heat and mass transmission in a stream across a wedge. The problem has been executed for MHD incompressible viscous fluid, which annexes the impact of thermophoresis. The sequels of chemical reactions and energy sources have also been encountered. The resulting equations are transmuted as nondimensional forms and a numerical method is executed to solve the same. The numerical results for velocity, temperature, and concentration distributions are illustrated in the form of graphs for various dimensionless parameters affecting the problem. Numerical data are computed for skin friction coefficient, Nusselt number, and Sherwood number for different parameters. The results have been depicted for possible cases by means of pictorial visualizations. The present study has importance in various sectors of industrial and engineering applications.     

Energy software programs for educational use

A package of six fully interactive energy software programs was developed for educational use. The first three programs can be used to simulate energy systems, while the rest three can be used to calculate some characteristic values, which can be used separately or in conjunction with the first three programs. The first one is a multimedia program for an active solar hot water system. It accounts for a large number of parameters and can be used to investigate their effect on the thermal efficiency of the system. The second program is a transient simulation for thermal behavior of a building. It can be used to predict the temperature and relative humidity inside a building along with the heating/cooling load required to keep the temperature at a preset point. The third program has been developed for sizing solar thermal systems. The fourth program is a graphical representation of the apparent motion of the sun on the celestial vault. The fifth program calculates the thermophysical properties of a number of gases and liquids for a desired temperature. The sixth program represents graphically the psychrometric chart. The above-mentioned programs, are useful tools for education in energy, suitable for high school students and Universities. It can also be used for an extensive set of exercises in the tertiary education sector.     

风力机叶片检测中的机器视觉技术

风力机叶片是风力机接收风能的关键构件。作者采用激光投影法实现叶片型面的非接触全型面测量。对叶片视觉图像进行预处理，提高测量系统对图像的识别精度。利用数学方法构造叶片翼型曲线函数，设计动态视觉跟踪算法加快图像处理速度，提高测量效率。提出智能化机器视觉快速测量策略。对叶片加工的自动化和数字化具有一定的意义。     

配125MW机组锅炉技术改造的研究

论述了锅炉热风温度偏低 ,排烟温度偏高的原因 ,研究分析了各种可能的改造方案 ,介绍了黄岛发电厂锅炉管式空气预热器采用螺旋槽管及回转式空气预热器波形板的改造方案 ,给出了改造后的试验结果。     

Sizing optimisation of stand-alone photovoltaic generators for irrigation water pumping systems

This paper mainly presents an efficient non-conventional direct method for sizing optimisation of stand-alone photovoltaic (PV) generators for supplying AC-motor-based irrigation pumping systems. The efficiencies of various elements comprising a PV pumping system and the effects of PV-array tilt are taken into account. The strong impact of the tilt angle on the optimal sizing of a PV generator is demonstrated. Extensive analysis of the meteorological conditions of the study site is performed. An appropriate solar correlation model for the design site is determined. The optimality of the determined capacity and tilt angle for a PV generator is evaluated by calculating several optimality indicators. The proposed method is compared with the Kenna and Gillett method and the RETScreen method for suggesting the nominal power for PV generators. The results show the capability and accuracy of the proposed method in optimally sizing stand-alone PV generators for irrigation water pumping systems.