宝鸡峡渠首加坝加闸工程坝段岩基L_0缓倾角裂隙处理

宝鸡峡渠首加坝加闸工程 坝段基岩存在L0缓倾角裂隙,针对其特点,提出两种处理方法;根据工程进度计划、工程投资经济性、和工程质量的要求进行技术经济分析,采用大开挖的处理方法。     

宝鸡峡渠首加坝加闸工程Ⅲ坝段岩基L0缓倾角裂隙处理

宝鸡峡渠首加坝加闸工程Ⅲ坝段基岩存在L0缓倾角裂隙,针对其特点,提出两种处理方法;根据工程进度计划、工程投资经济性、和工程质量的要求进行技术经济分析,采用大开挖的处理方法.     

轴流压气机前加级设计

为提高轴流压气机的性能,可以在现存压气机通流部分前加级,这是一种行之有效的方法。本文描述了前加级的设计方法,介绍了两台轴流压气机的设计计算,在国内民用机组方面,其设计参数是较高的.经一台机组的初步试验表明,设计是成功的。     

全保护自动加氧技术的研究及应用

国内超临界火力发电机组常规采用传统加氧方式,经常在加氧处理后出现过热器、再热器氧化皮大面积脱落,进而导致机组出现堵管、爆管事故,国内热力发电机组加氧设备经常处于停止运行状态。全保护加氧技术通过在凝结水水泵入口前、除氧器下降管两侧、1#高压加热器汽侧分别加氧,解决了给水系统腐蚀问题,同时避免了传统加氧处理技术引发的再热器、过热器氧化皮脱落的风险,解决了高加疏水系统的腐蚀问题。     

加弯叶型在轴流风机噪声控制中的应用研究

在风机叶轮直径不变的条件下,利用叶型加弯方法对轴流风机进行改型设计,可在较低转速下获得设计全压,从而达到控制风机气动噪声的设计目标。根据轴流风机的设计参数设计了一个基于原始叶型、转速为9 000 r/min的风机模型和一个基于加弯叶型、风机转速为8 000 r/min的风机模型,两者的叶型升力系数分别为0.72和1.02。通过数值模拟和试验对两风机的流场与性能进行研究。结果表明:在设计工况附近,原始叶型风机与加弯叶型风机的性能基本相近,全压误差约为6%。在半转速运行条件下,加弯叶型风机模型的气动噪声比原始叶型风机降低了1.4 d B,而气动性能基本不变。     

蒸汽加氧冲管在彭城发电厂的应用

徐州彭城发电厂＃１炉在省内首次采用加氧冲管新工艺，＃２炉在总结＃１炉加氧冲管经验的基础上，进一步提高加氧浓度，取得了明显的效果。本文阐述了蒸汽加氧冲管的基本原理，同时介绍了彭城发电一期工程两台锅炉采用蒸汽加氧冲管的实际应用情况，实践表明，无论在冲管能耗及工期方面，还是冲管效果方面，采用适当的加氧浓度对蒸汽加氧冲管都具有显著的影响。     

恒惠渠渠首加闸与恒河水资源利用

本文通过对恒惠渠渠首加闸工程介绍、分析,揭示了该工程建设的必要性和可行性,在流域水资源利用方面所发挥的作用。     

钢筋混凝土结构裂缝的预防与处理

根据设计及施工中的工程实践,提出了钢筋混凝土结构中容易出现裂缝的部位,并对裂缝产生的原因进行了分析,指出在设计、施工以及使用过程中预防裂缝的措施;并提出了处理裂缝的四种方法:低压注浆法、表面涂抹覆盖法、涂抹加玻璃丝布法、开槽填充法。     

浅析高加解列中的若干问题

通过对华能大连电厂二期美国西屋公司350MW汽轮发电机组负荷210MW时手动逐一解列高加,定性分析工况要点,总结出了一些经验,优化了高加保护动作的处理措施。     

十四级亚音速轴流压气机加级设计与整台调整试验

利用优良的母型压气机,用加级方法发展高性能的压气机是国内外广为采用的方法。本文详细的介绍了一台十四级压气机的加级设计思想,设计计算方法及整台压气机的调整试验,并给出了调整后的压气机试验特性曲线。试验证明该压气机设计是成功的,压气机的全面技术指标符合设计要求。     

Review of theory of distortion and disintegration of liquid streams

Linear and nonlinear analyses of the instabilities and distortion of liquid streams injected into a gaseous media are discussed. The various fundamental mechanisms and the predictive capabilities for the distortions are emphasized. Round jets, planar sheets, annular sheets, and conical sheets are discussed in detail. The balance between capillary and inertial forces is primarily examined. The method for simplifying the analyses in the case of thin liquid sheets is discussed. The capabilities for representing the droplet size distribution that follows the stream disintegration are outlined.     

石油化学工业炼油化工一体化技术的进展

炼油化工一体化体系的运行需要炼化一体化技术的支撑。介绍了炼油化工一体化技术的进展,包括：①多产型炼化一体化技术,如多产石脑油技术、多产芳烃技术、多产低碳烯烃技术;②节约型炼化一体化技术,如干气中C2分离作乙烯原料技术、FCC干气中的乙烯与C4烯烃歧化制丙烯技术;③炼化一体化生产优化组合技术,如多产裂解料的炼油-乙烯一体化组合技术、节省石脑油的炼油-化肥一体化氢气链组合技术等。     

Development of Prometey local approach and analysis of physical and mechanical aspects of brittle fracture of RPV steels

In the present paper, the probabilistic model for brittle fracture toughness prediction proposed by the authors earlier and known as the Prometey model, is formulated with two stochastic parameters—the critical stress for microcrack nucleation σ_d and the critical stress for microcrack propagation S_C The stochastic dependence of the critical stress for microcrack propagation S_C is experimentally studied for an RPV steel. The Prometey model with two stochastic parameters is applied to model the effect of irradiation on the fracture toughness transition curve and to predict the loss of constraint associated with shallow cracks.     

Overview of the modeling of lithium-ion batteries

简述了锂离子电池等效电路模型和电化学模型的研究进展。由于具有耗时短、技术开发效率高等优点,仿真模型被广泛应用于锂离子电池衰减机制分析、状态诊断及寿命预测。锂离子电池仿真模型主要包括等效电路模型和电化学机理模型。等效电路模型主要应用于锂离子电池荷电状态诊断。电化学机理模型主要应用于锂离子电池衰减机制分析和健康状态诊断,并为寿命预测提供技术支持。等效电路模型的结构过于单一,在锂离子电池寿命后期适用性降低。电化学机理模型结构复杂,计算量大,在线性应用能力较差。总结了现阶段常用的锂离子电池等效电路模型和电化学模型的建模原理及模型结构,阐述了每种模型在电池研究中的具体应用,并分析了其各自的优势及局限性。通过以上分析,并结合最新的建模理论,对建立具有高精度、高适用性锂离子电池仿真模型的研究方向进行了展望。     

Code of practice for high-temperature testing of weldments

The present paper reports on a code of practice (CoP) for high-temperature testing of weldments for industrially relevant specimens. Novel aspects of the CoP include advice for testing weldment zones using different specimen geometries. Those specimens differ from the standard compact tension C(T) specimen recommended in the only available creep crack growth (CCG) testing standard ASTM E1457. Recommendations for the required number of tests, techniques for testing, treatment of test records, reduction of test data and data analysis are presented. Associated specimen selection guidelines for industrial creep crack initiation (CCI) and growth testing are also described. Validation tests carried out on P22 and P91 weldments, and base metals of 316H steel and C-Mn steel using relevant specimen geometries are briefly described. The CoP contains recommended K and C* solutions, Y functions and η factors, which are used to determine values of the fracture parameters K and C* for the specimen geometries considered. Information from these new tests, together with a review of previous CCG tests on non-standard geometries, have been used in recommending the best method of analysis for CCI and CCG data for a range of creep brittle to creep ductile welded materials.     

柴油机下置式凸轮配气机构动力学分析

针对下置式凸轮配气机构建立多质量动力学分析模型,以MATLAB软件为平台编制了下置式凸轮轴配气机构动力学分析程序,对6V150柴油机配气机构进行动力学分析,所得计算结果与实际情况比较吻合,为配气机构进一步优化设计奠定了基础。     

Impact of nanostructuring on the enthalpy of formation of metal hydrides

High-energy ball milling has been shown to decrease the release temperature, increase the reaction kinetics, and lower the enthalpy of formation of metal hydrides in certain cases. This paper discusses several potential mechanisms for the reduction of the enthalpy of formation. Although the increased surface and grain boundary energy could play a role in reducing the enthalpy of formation, the predicted magnitude is too small to account for experimental observations. Structural deformation and the associated volume change provide another mechanism for the change in this thermodynamic property. We employed three equations of state models to characterize the excess energy present in the deformed regions and found that the excess volume provides a plausible explanation for the experimentally observed change in thermodynamic properties.     

Application of MLP-ANN as a novel predictive method for prediction of the higher heating value of biomass in terms of ultimate analysis

In the recent years, the energy issue is known as one of the main entries for economic and social development of human. So the biomass fuels as one of the approaches for supplying energy become the attractive topic for investigation. The higher heating value (HHV) is a key parameter for evaluation of energy of biomasses; so in the present study, a novel work was done to predict HHV as a function of ultimate analysis by utilization of multi-layer perceptron artificial neural network (MLP-ANN). To this end, a total number of 78 actual data were extracted from reliable references for training and validation of the model. The predicted HHVs were compared with the experimental data graphically and statistically, and the obtained results expressed that the MLP-ANN has a great potential for estimation of HHV of biomasses; so this approach can be used as a simple and accurate tool for forecasting HHV in terms of ultimate analysis. Based on the obtained results, this approach becomes one of the applicable softwares in industries.     

Effect of orientation on thermal performance of a building

The effect of aspect ratio and orientation of a non-airconditioned building on its thermal performance has been analysed in terms of discomfort index for hot-dry and composite climates. It is shown that the discomfort index for east-west orientation is smaller than that for north-south orientation but the difference even for the largest aspect ratio considered is not more than 10%.     

柴油机低排放设计技术的发展及关键接术分析

介绍柴油机低排放设计技术的发展现状；分析了低排放设计所涉及的主要研究内容和关键技术，为提高现有柴油机产品的设计水平指明了改进方向。