消除复合抛物面聚光器二次反射的设计研究

建立未截短的原复合抛物面聚光器(CPC)、1/2截短CPC以及消除二次反射设计CPC的数学模型,根据光线追踪法和蒙特卡罗法,在几何聚光比为2~10内,计算CPC高度与出射光孔宽度的比值,并依据该比值分析CPC的经济性,计算CPC最佳均匀面上的非均匀度和最大辐照度,进而分析CPC聚光均匀性.结果表明:在相同几何聚光比下,消除二次反射设计CPC的经济性和聚光均匀性最好.     

复合抛物面聚光器(CPC)光学分析研究

阐述了复合抛物面聚光器（CPC）的设计原理和光学原理，简单介绍了复合抛物面聚光器（CPC）与不同接收器的结合形式。主要介绍了平板型CPC和圆管型CPC的设计方法和相关量的计算公式的推导结果最后主要说明了截取比在CPC系统中对系统效率和系统的经济性的影响，认为合适的截取比可增加CPC的利用率并且可大大的节省材料，对CPC的推广应用很有利。     

Homogenization Function of Microchannel on Heat Absorber with Compound Parabolic Concentrator

Microchannels offer unique advantages on heat transfer performance. In this paper, microchannels are applied to the compound parabolic concentrator(CPC) system. A multi-physical field coupling model based on Finite Element Method is proposed to investigate the homogenization effect of the microchannel heat absorber on the CPC non-uniform concentration. The energy conversion process from optics to heat is simulated using TracePro software, and the heat transfer processes in the microchannel are c...     

太阳能槽式直接蒸汽发电系统集成方案的设计

以太阳能槽式直接蒸汽发电(简称DSG系统)为研究对象,根据南京全年辐射强度统计数据及全年辐射平均强度确定该系统汽轮机的型号、集热器的个数和给水流量等参数,给出了一个无储热的5MW太阳能槽式直接蒸汽发电系统的设计方案。     

废气复合透平系统的热技术经济学分析和设计优化

用热技术经济学原理与ＢＯＸ非线性约束（复合型）优化法相结合的方法,对大型柴油机动力系统中废气复合透平系统进行了热作设计优化计算。探讨的方法也可用作动力厂（站）可行性研究阶段方案设计时的参考。     

生物质型煤研究现状及发展

当前生物质型煤技术正在逐步发展,其应用的规模和范围正在不断扩大.本文讨论了发展生物质型煤的意义,详细介绍了国内外生物质型煤的发展历程及现状,介绍了一些目前采用的新技术和存在的问题.最后对生物质型煤的未来进行了展望,指出生物质型煤在节能及环保方面骀将大有作为.     

大位移井侧位抛物线剖面设计的数值计算

侧位抛物线剖面是大位移井轨道设计中常用的剖面类型。对侧位抛物线剖面设计求解过程中的求侧位抛物线初始点井斜角的数值方法和从段长求井斜角的数值方法进行了分析,指出其关键是求解侧位抛物线初始点井斜角所满足的一个三角函数方程。用倍角公式可将该三角函数方程转化成一个四次代数方程,然后用求根公式直接求出解析解。用解析解可简化侧位抛物线剖面设计过程,减少计算工作量,提高计算速度。侧位抛物线井段参数计算中需要通过段长公式来反求井斜角,给出了反求井斜角的二分法。本文的算法可应用于大位移井轨道设计的软件开发。     

Some Estimates of a System of Degenerate Parabolic Equations

The Dirichlet problem on a coupled system for degenerate parabolic equations is investigated in this paper. The aim is to show the existence, uniqueness of maximum solution, the continuity on the coupled functions, and time-dependent estimates.     

复合支护在松软地层中的开发及应用

针对张端井田地质构造复杂,构造应力及矿压显现,从现在巷道的支护理论出发,结合山西焦煤霍州煤电集团张端煤业有限公司在掘进主斜井穿越表土段与强风化基岩层不同岩性松动范围方面,分析了锚网喷及钢筋混土联合支护巷道、加固围岩的作用原理及施工技术,在现场取得了很好的技术经济效益.     

槽式太阳能直接蒸汽发生系统的热力特性研究

  [目的]  研究典型的槽式直接蒸汽循环系统的热力性能,给出该系统的结构组成和主要性能参数。针对DSG系统的两相区复杂的换热问题,结合两相区的实际流型,考虑分层现象对实际换热过程的影响,更加准确地对两相区的换热过程进行模拟研究。  [方法]  基于槽式集热器内的流动型态,建立槽式集热两相区内的传热模型,利用Matlab编程,针对槽式集热器内的DSG过程进行模拟。  [结果]  揭示了DSG技术沿着管长方向的换热特性变化规律,分层现象大约出现在两相流区域干度为0.7～0.8之间的位置,分层现象的出现降低了管内工质与金属管管壁之间的对流换热系数,减弱了换热效果。  [结论]  该研究为DSG电站的设计和运行提供了参考依据,验证了DSG集热场的最佳布置方式为再循环式。     

槽式太阳能聚光集热器传热性能研究

建立了槽式太阳能聚光集热器单侧吸收高热流密度的传热数学模型.该传热数学模型将金属吸热管壁面所能接受到的非均匀热流简化为矩形分布,考虑了金属吸热管管壁的周向导热,选取Dudley的试验数据验证了传热数学模型的可靠性并分析了影响集热器传热特性的主要因素.通过Fluent软件研究了槽式太阳能聚光集热器金属吸热管的周向温度分布规律.结果表明:该传热数学模型具有一定可靠性;流体温度、太阳辐射强度和流体体积流量是影响集热器管内换热特性和管壁周向温度分布的主要因素.     

Development of a Hydrogen Refueling Station Design Tool

In the last couple of decades, there has been a growing concern in what effects fossil fuels are having on the environment, resulting in governments and governing organizations issuing stringent emission standards in an effort to curve their environmental damage. To meet these new standards, the transportation industry has been conducting research into alternative fuels, such as hydrogen, but one critical problem utilizing hydrogen is that there is almost no infrastructure. A network of hydrogen refueling stations similar to modern gasoline stations will be required to be constructed to meet future demand. The hydrogen refueling station model was created to aid in designing hydrogen facilities, thus accelerating their development while reducing design cost. A model was created using Simulink consisting of an electrolyzer that generates hydrogen, a compressor, numerous storage tanks, a dispensing unit that transfers hydrogen, and a vehicle component that consumes hydrogen fuel. The model was validated using data from existing hydrogen refueling stations, and the data obtained from testing the previous version of the hydrogen refueling station model to determine model accuracy and if the model has improved. The model has demonstrated that it can produce reasonable results for a station's performance and has improved compared to the previous version.     

复合防水屋面设计和施工中的几个问题

复合防水屋面可以采用两种性质不同的防水材料复合使用,使其优点互补,达到提高屋面整体防水性能的目的。但若设计、施工不合理,很难取得预期效果。本文从复合防水屋面的材料、设计、施工几个方面,阐述应该注意的几个问题。     

Analysis of Thermal Stress in a Functionally Graded Coating on a Parabolic Substrate

The thermal stress field in a functionally graded coating on a parabolic substrate, where the material properties vary along the thickness direction, is considered. The closed-form solutions of thermal stresses related to compositional gradient, coating thickness and substrate curvature were obtained based on force and moment balances, and then numerical results are presented for several special examples. It is found that the magnitude and distribution of thermal stress in the functionally graded coating system with general geometrical shape can be designed properly by controlling the compositional gradient, coating thickness and substrate curvature.     

绝热涡轮复合发动机用动力涡轮结构设计和改进

通过试验和结构改进,研制成功了转子采用滚动轴承和浮动轴承共同支承的动力涡轮,它在工作范围内的任何转速下均运行平稳,且组成绝热涡轮复合发动机后,在配机调试时达到了安全运行的目标。     

Homogenization of a Micro-Periodic Helix with Parabolic or Hyperbolic Heat Conduction

We study thickness-shear vibrations of a crystal plate constrained by two elastic layers with initial deformations caused by a temperature change. The theory for small deformations superposed on finite biasing deformations in a thermoelastic body is used. It is shown that the resonant frequencies of the incremental shear vibration shift whentemperature changes. The temperature-induced frequency shift depends linearly on the temperature change and can be used for temperature sensing. The dependence of the temperature-induced frequency shift on various material and geometric parameters of the structure is examined.     

Hypergeometric Functions and Parabolic Partial Differential Equations

We investigate the summability of formal power series solutions of parabolic linear partial differential equations with exponential coefficients.2000 Mathematics Subject Classification. 35C10, 35C20.This research was supported by a Marie Curie Fellowship of the European Community program Improving Human Research Potential under contract number HPMF-CT-2002-01818.     

复合床式低倍率循环流化床锅炉的研制开发

本文全面分析了较高循环倍率循环流化床锅炉所存在的技术问题,提出采用设计经验成熟、运行稳定可靠、热效率高、电耗低的低循环倍率循环流化床锅炉技术来实现循环流化床锅炉的大型化的新技术思想,并据此研制开发出复合床式低倍率循环流化床锅炉新技术。通过介绍和分析复合床式低倍率循环流化床锅炉的技术原理及技术特点,展示新炉型所具有的锅炉主要部件的灵活布置方式,为循环流化床锅炉的大型化指出了新的发展方向。     

不对称盒形件落料拉伸复合T艺及其模具设计

通过工艺分析,对传统工艺进行了改进,采用了落料拉伸的复合结构应用于不对称的盒形零件的加工,解决了单工序模由于零件形状不规则而产生的定位不可靠、下料繁琐等问题.介绍了复合模具的结构设计及工作过程.经生产验证,该模具性能可靠,运行平稳,提高了产品质量和生产效率,降低了劳动强度和生产成本.