新型高效脱硫泵的研制

基于固液两相流泵设计方法,采用叶片进口超长延伸及叶片极大扭曲的方法来设计叶轮,压水室设计为螺旋形双流道;结构上创新地设计了压水室耐磨板间隙自动补偿装置和叶轮轴向位移调节装置,机械密封采用集装式结构,轴承箱设计为可放气式结构,进而设计了一种新型高效的脱硫泵。采用自行研制的M26-23V合金钢,用熔模铸造工艺进行加工,并对脱硫泵的性能进行了检测。结果表明,泵的各项指标都满足设计要求,泵的额定点效率达到85.28%,该泵设计合理,效率高,性能曲线平坦,高效率区宽,有无过载特性,且耐磨性能好,使用寿命比同类产品提高了25%以上。该泵的研制成功,对于促进我国脱硫泵的国产化、电力行业的节能减排以及行业的经济效益和社会效益的提高具有重要的现实意义。     

重型汽车钢板弹簧的热处理

研究了代替52 CrMnBA钢用于重型汽车少片钢板弹簧的50 CrV钢的热处理工艺。研究结果表明,50 CrV钢板弹簧用PAG水溶性淬火介质淬火可明显提高淬透性和硬度均匀性;弹簧总成的疲劳寿命大于12万次,符合技术要求。道路试验表明,采用50 CrV钢制造的重型汽车少片钢板弹簧性能完全满足使用要求,且成本明显降低。     

Influence of radial and axial runouts on surface roughness in face milling with round insert cutting tools

In face milling processes, the surface quality of the machined part depends on many factors, including feed, cutting tool geometry and tool errors. In this work, a numerical model for predicting the surface profile and surface roughness as a function of these factors is presented, incorporating a random values generation algorithm that makes it possible to determine the variation in surface roughness from the values that can be adopted by tool errors. This work is focused on round insert cutting tools and the influence of tool errors such as radial and axial runouts. The results that correspond to a number of teeth equal to 4, insert diameter of 12 mm, depth of cut of 0.5 mm, cutting speed of 120 m/min and feed of 0.4–1.4 mm/rev are analysed. Milling experiments are made to verify the validity of the model and the discrepancies between the experimental and theoretical surface profiles are assumed to be a consequence of different factors such as the variation in undeformed chip thickness along the surface profile.     

FRP海水珊瑚混凝土与普通钢筋混凝土结构的全寿命周期成本比较

以海洋工程为例,从全寿命周期成本的视角出发,在一定简化条件下对FRP海水珊瑚混凝土结构和普通钢筋混凝土结构的成本进行对比,并对影响成本的因素进行分析。计算结果表明,在施工方案及工程量相同而材料运输、维护方案不同的条件下,FRP海水珊瑚混凝土结构的全寿命周期成本较普通钢筋混凝土结构具有优势,且在具有一定特性的结构中优势相当显著,因而具有良好的经济性。     

Round robin on accelerated life testing of solar absorber surface durability

As degradation by ageing of solar absorber surfaces was identified to be an important quality factor, the Working Group MSTC (‘Materials in Solar Thermal Collectors') of the IEA-SHCP (International Energy Agency-Solar Heating and Cooling Programme) worked out a general test procedure for accelerated lifetime testing (ALT) of these materials, based on methods established by the former Task X of the IEA SHCP. The qualification test procedure was adopted by ISO and is presently dealt within ISO/TC 180 ‘Solar Energy'. The standard proposal in detail describes a procedure how to test the long-term stability of an absorber surface for the use in flat plate collectors for domestic hot water systems. The collectors service lifetime is assumed to be 25 years, at least. Degradation caused by thermal loads, high humidity and condensation and sulphur dioxide are regarded. In order to examine the feasibility and reproducibility of the test method the Working Group MSTC initiated a round robin test in accelerated life testing of solar absorber surfaces. The test was performed according to the ISO standard proposal dated January 1997. In total, five different industrially manufactured absorber coatings were available to the three participating laboratories. Tests concerning the thermal stability as well as the resistance to high humidity and condensation were performed by all three laboratories. The test for determining absorber surface corrosion resistance to air of high humidity containing sulphur dioxide was carried out by one lab only. The outcome of the round robin test shows very good agreement of the results of the different coatings tested for all of the laboratories. The feasibility and reproducibility of the method was fully confirmed.     

Qualification test procedure for solar absorber surface durability

A general test procedure for the qualification of solar absorber surface durability has been developed based on the results of a comprehensive case study performed within the framework of the IEA Solar Heating and Cooling Programme Task X. It was assumed, in the development of the qualification procedure, that the intended use of the absorber surface to be qualified, was in single-glazed flat plate solar collectors for domestic hot water production. The absorber surface should be considered qualified if it met the requirement of a design service life of 25 years with maximum loss in the optical performance of the absorber surface corresponding to a 5% relative reduction in the performance of a solar domestic hot water system. The testing procedure, consisting of three kinds of constant load-accelerated life-time tests, was limited to simulation of the following three kinds of absorber surface degradation processes: (a) high-temperature degradation, e.g. oxidation, (b) degradation by the action of moisture or condensed water on the absorber surface, e.g. hydration or hydrolysis, and (c) degradation caused by high humidity air containing a small concentration of sulphur dioxide as an airborne pollutant, e.g. atmospheric corrosion. To quantify expected environmental stress on the absorber surface related to the environmental factors of interest, microclimate data, representing typical service conditions for absorbers in single-glazed flat plate collectors for domestic hot water production were used.     

基于高级Petri网的仿真剧情正规校核方法

针对仿真剧情主观校核不理想这一问题,提出了基于高级Petri网的仿真剧情正规校核方法．首先给出仿真剧情的形式化定义,并分析仿真剧情可能存在的错误类型;其次给出仿真剧情到高级Petri网的映射途径,并给出基于高级Petri网的仿真剧情校核准则和算法,此外,还给出实现仿真剧情动态校核的推理规则和机制;最后给出了一个正规校核工具框架．实际应用已经证明了该方法的有效性．     

Durability of polymeric glazing materials for solar applications

The economic viability of solar collector systems for domestic hot water (DHW) generation is strongly linked to the cost of such systems. Installation and hardware costs must be reduced by 50% to allow significant market penetration. An attractive approach to cost reduction is to replace glass and metal parts with less expensive, lighter weight polymeric components. Weight reduction decreases the cost of shipping, handling, and installation. The use of polymeric materials also allows the benefits and cost savings associated with well established manufacturing processes, along with savings associated with improved fastening, reduced part count, and overall assembly refinements. A key challenge is to maintain adequate system performance and assure requisite durability for extended lifetimes. Results of preliminary and ongoing screening tests for a large number of candidate polymeric glazing materials are presented. Based on these results, two specific glazings with moderate and poor weathering stability are selected to demonstrate how a service lifetime methodology can be applied to accurately predict the optical performance of these materials during in-service use. A summary is given for data obtained by outdoor exposure and indoor testing of polyvinyl chloride (PVC) and high temperature modified polycarbonate copolymer (coPC) materials, and an initial risk analysis is given for the two materials. Screening tests and analyses for service lifetime prediction are discussed. A methodology that provides a way to derive correlations between degradation experienced by materials exposed to controlled accelerated laboratory exposure conditions and materials exposed to in-service conditions is given, and a validation is presented for the methodology based upon durability test results for PVC and coPC.     

数控机床运动误差检测与仿真

本文介绍了一种测量数控机床和加工中心运动误差的新装置－双球规的结构特点，测试原理及测试方法，给出数控机床常见的各种运动误差矢量表达式特征模型，并进行了计算机仿真研究。     

导弹阵地战场抢修统一过程模型

针对导弹阵地当前决策中过分依赖经验决策的现象,提出导弹阵地战场抢修统一过程模型。从导弹阵地内的保障装备和弹药全寿命过程出发,发掘其中的战场抢修统一过程,将其分解为装备战伤评估、战场抢修方案决策、战场抢修备件组织、战场抢修实施和战场抢修效果评估5个子过程。同时,通过应用IDEFO建立了上述过程的过程模型。该研究可为今后进行战场抢修决策平台的快速开发提供参考。