太阳方位角的公式求解及其应用

基于对通过"天球理论"所推导出的太阳方位角与经纬度、时间等参量关系曲线特征的分析,提出了太阳方位角的求解条件,并最终确定了求解公式.经过检验,证明该公式能够真实反映太阳的运行轨迹.同时介绍了该公式在一项太阳能利用工程设计中的应用方法.     

综合节水灌溉技术研究与应用

针对水稻灌溉全过程的每一环节,总结,分析当今国内外水稻灌溉先进技术,提出了水稻综合节水灌溉技术优选模型,并结合湖南省的具体情况,建立了现状条件下灌区渠系利用系数测算的理论模型,研究提出了一种新的水稻节水灌溉制度－“控灌中蓄”     

钌基氨合成催化剂工业化应用的模拟与分析

上世纪90年代,KBR将新型钌基催化剂成功应用于氨合成工业生产,并且形成以钌基催化剂为核心的KAAP工艺。钌基催化剂由于其远高于铁基催化剂的活性特征,已经在提高产量、降低能耗方面显示出无可比拟的优越性能。钌基催化剂作为氨合成第二代催化剂,与铁基催化剂相比,具有活性高,使用寿命长,操作条件相对缓和等优点,国内已经开发成功,但未见工业化应用报道。针对某大型氨厂氨合成回路扩能改造,提出对现有3个合成塔中的第三塔进行改造,改造后第三塔装填钌基催化剂,催化剂床层由一个增加为两个,床层之间有换热器。应用模拟软件Aspen Plus对该方案进行模拟研究,并与现有改造方案进行对比分析。结果表明,本方案在不新增合成塔数量的前提下,即可实现提高液氨产能35%的目标;改造后的3个合成塔运行参数满足工业生产要求,钌基催化剂在较高氨含量下仍然表现出优异的活性;与现有新增合成塔的改造方案相比,本改造方案在成本方面具有较大的经济优势。     

柴油发电机组整机振动及防振

简要分析了柴油发电机组的振动对外界和电站内部零部件的影响,及外部振动同样会引起电站振动和电站内部零件的损坏,在此基础上提出柴油发电机组的防振措施。叙述了隔振器的性能特点以及选择隔振器的方法和步骤,给出隔振弹性支承的主要参数和计算方法,最后指出隔振弹性支承的布置力求对称以减少独立和耦合振动型式。     

Overall performance of a heat sink-fan/pump unit and its optimum design

The forced-convection-cooling performance of a fin array is dependent on its pressure-loss characteristics as well as on the pressure-discharge characteristics of fans/pumps driving the working fluid. From this point of view, the overall performance of the forced-convection fin array has been analyzed, considering these characteristics and introducing a new dimensionless parameter F, which governs the overall performance. Based on the results, optimum design methods for forced-convection-cooling fin arrays in practical use are proposed. © 1998 Scripta Technica, Heat Trans Jpn Res, 26(8): 515–527, 1997     

Overall design optimization of wind farms

An Evolutive Algorithm (EA) for wind farm optimal overall design is presented. The algorithm objective is to optimize the profits given an investment on a wind farm. Net Present Value (NPV) will be used as a figure of the revenue in the proposed method. To estimate the NPV is necessary to calculate the initial capital investment and net cash flow throughout the wind farm life cycle. The maximization of the NPV means the minimization of the investment and the maximization of the net cash flows (to maximise the generation of energy and minimise the power losses). Both terms depend mainly on the number and type of wind turbines, the tower height and geographical position, electrical layout, among others. Besides, other auxiliary costs must be to keep in mind to calculate the initial investment such as the cost of auxiliary roads or tower foundations. The difficulty of the problem is mainly due to the fact that there is neither analytic function to model the wind farm costs nor analytic function to model net generation. The complexity of this problem arises not only from a technical point of view, due to strong links between its variables, but also from a purely mathematical point of view. The problem consists of both discrete and continuous variables, being therefore an integer-mixed type problem. The problem exhibits manifold optimal solutions (convexity), some variables have a range of non allowed values (solutions space not simply connected) and others are integers. This fact makes the problem non-derivable, preventing the use of classical analytical optimization techniques.     

Investigation of a Process Scheme for Overall Recovery and Bioconversion of Lignocellulosic Biomass Components

It is shown that enzymatic hydrolysis of biomass can decisively contribute to supplement indigenous sources of fuels and chemicals. The utilization of hemicellulose and cellulose requires preliminary pretreatment of biomass which can be efficiently accomplished and references are given for the optimization of recovery procedures. Bioconversion of both hemicellulose and cellulose is discussed and the effects of temperature, pH, substrate concentration and product inhibition are shown on the basis of experimental evidence. Process by-products-low molecular weight chemicals formed during biomass pretreatment - were fully characterized and details are reported of the analytical methods which were employed. It was found that higher sugar yields are reached when hydrolysis is performed making use of enzymic composites from different strains.     

整机环境下的风扇_增压级叶片气动优化

采用自主研发的三维粘性气动优化设计平台对某双涵道风扇/增压级进行了气动设计优化;采用NURBS技术对该风扇/增压级各排叶片进行了参数化造型,包括二维叶型的参数化表达以及基选线的弯、扭联合造型;采用NUMECA商用软件进行了风扇/增压级三维内外涵联算作为气动性能评估指标;基于该风扇/增压级三维内外涵联算,采用iSIGHT优化软件对风扇/增压级各排叶片进行了气动优化设计.在整机流量降低0.342 8%的情况下,内涵增压级效率提高了1.43%;对风扇优化,在整机流量基本不变的情况下,整机效率提高了1.566%,并扩大了增压级的稳定工作范围.     

CKD7B型机车的总体设计

介绍了出口缅甸的CKD7B型机车的总体设计。该机车车体采用轻量化设计,动力装置采用美国卡特皮勒公司生产的CAT3516B型柴油机,装车功率1 360 kW,采用交-直流电传动,转向架采用3台结构相同的可互换的两轴转向架,轴重为12.7 t,可通过62 m的最小曲线半径,最高运行速度为100 km/h。     

输电线路铁塔整体移位

从现场布置、受力计算、施工步骤等方面,介绍了330kV双回路直线塔整体移位的施工方法。实践证明,其具有成本低、施工程序简化、工期短、安全可靠等优点,从而减少了停电时间,实现了多供电。经济效益显著。     

双层壁冷却结构综合冷却效率和相对压力损失多目标优化

在典型燃烧室工作环境下,针对特定双层壁冷却结构,以综合冷却效率和相对压力损失为优化目标,采用径向基神经网络构建数学模型,通过遗传优化算法实现多目标优化,旨在提高其气动和传热性能。在给定的双层壁冷却结构参数范围内,优化后双层壁冷却结构的最大综合冷却效率为0.89,而相对压力损失可降至0.17%。