太阳能干燥系列讲座(1)太阳能干燥——太阳能热利用中不可忽视的领域

一物料干燥的能耗与环境污染 干燥作业涉及国民经济的广泛领域,是许多行业不可缺少的工序.在粮食、食品、果品、药材、木材、皮革、橡胶和陶瓷等许多产品的加工处理过程中,干燥作业对产品的质量和成本影响很大.     

第二讲认识太阳利用太阳

一、太阳与太阳能 众所周知,在浩翰的宇宙中有一颗离我们最近的恒星--太阳.现代科学表明太阳距离我们相当遥远,达到1.5亿km,虽然太阳光的传播速度为30万km/s,但我们在地球上所见到的光线已经是8min之前从太阳发出的光线了.太阳的直径为139万km,而地球直径仅为1.27万km,太阳的直径约为地球直径的109倍,其体积则比地球大130多万倍.尽管如此,由于距离遥远,太阳张角仅仅为32′.     

燃料电池技术的发展现状

燃料电池是不经燃烧过程直接把燃料的化学能转化为电能的装置,具有能量转换效率高、污染物排放量少的独特优点.简述燃料电池工作原理,比较各类燃料电池的特性,并介绍目前燃料电池在国内外的应用现状,同时指出目前影响燃料电池商品化的主要因素.     

水资源对我国工业发展的影响及对策建议

党的十六大提出了全面建设小康社会的奋斗目标,十六届三中全会又强调指出,要树立全面、协调、可持续的发展观,促进经济社会和人的全面发展.树立和贯彻科学的发展观,很重要的一个方面,就是要坚持人与自然的和谐,正确处理发展与资源、环境的关系.水是人类的生命线,因此,水不仅是重要的自然资源,而且是战略资源.     

基于CFD技术的迷宫式油气分离器优化设计

应用计算流体动力学软件FLUENT对汽车发动机气门室罩内的迷宫式油气分离器进行三维两相流场和油滴颗粒分离效率的数值模拟.通过计算四种分离器结构参数(出口位置、出口直径、V型槽间距和V型槽宽度)下的分离器的分离效率和压降损失,分析了各参数对分离效率的影响,得到分离器性能的规律性结论和分离器的最佳结构参数,用于指导迷宫式油气分离器的设计.     

壳牌基金会在中国

壳牌基金会是荷兰皇家/壳牌集团设立的全球非赢利机构,旨在为由于能源生产和消费而产生的社会和环境问题制定可持续的解决方案,并充分开发全球化的潜能,以改善弱势群体的发展前景.为了将社会投资与壳牌的核心业务及其作为跨国公司的特点明确联系起来,基金会确定了三大核心领域--可持续能源、可持续社会和可持续交通.(如需了解有关壳牌基金会的更多信息,请访问www.shellfoundation.org)     

济钢煤气资源利用走节约型之路

"十一五"期间钢铁工业的发展,要从人、自然资源、生态环境和科学技术更大的系统内来实现发展,在资源投入、生产、消费及废弃物处理的全过程中,不断提高资源的利用效率,把资源消耗、环境负荷的线性增加,转变为依靠科技进步、生态资源的循环来实现钢铁工业的发展,这种发展是可持续的、是符合科学发展观的本质要求的,济钢从"充分利用煤气资源"寻找到了突破口.     

第四讲 绿色的生物质能

一、生物质能概述 生物质能是人类使用的最古老的能源.随着世界经济持续快速地发展和人口数量迅速地增长,人类对能源的需求必然不断地增加,然而目前人类赖以生存的化石能源却正在迅速地减少.据预测,地球上蕴藏的可以开发利用的煤和石油化石能源将分别在200年、40年内耗竭,而天然气也只能用60年左右.     

光合光量子传感器校准的一些问题

介绍了光合光量子传感器的校准方法,只要有符合国家标准的辐照度标准灯,并用标准灯对适当级别的光谱辐射计进行校准后,就可在日光下供此类仪器定期校准之用.并证明了所介绍方法的实际可行性.由于LI-COR公司随LI-190型仪器发放的使用说明书中有关量子传感器的光谱响应曲线图前后不相一致,且未加说明,文中对此进行了重点论证和讨论.当前并不存在真正意义上的光量子传感器,实际所用的也只有能量传感器,以光量子单位表示的测量结果是经公式计算得出的.此外,还证明了量子单位测量结果与能量单位测量结果关系的一致性,如有需要,在校准时就可同时得出量子的和能量的两种灵敏度,从而免除了由于单位互换带来的误差.     

数据仓库中实体化视图联机维护一致性研究

在分析传统实体化视图连接算法的基础上,对EVM算法进行了改进,提出了分布连接算法,加入了选择性批处理思想并在限定时间内实现当DB中源数据发生变化时实体化视图得到相应的更新,确保DW能及时反映DB的现状及OLAP查询的一致性,达到对DW联机维护的目的.     

Drainage and economic utilization of methane from coal seams in the Jastrzebie mining-field

The paper presents the resources and present status of coal-seam methane from the mining field of JSW S.A., as well as trends in its application both in JSW S.A. plants and elsewhere. For the period 1999–2001, the dynamics of growth of methane utilization are shown. Perspectives of methane drainage are considered, with regard to both work and the realization of restructuring programs in the mining industry. Demand and supply of methane are discussed, taking into account real and potential opportunities. An assessment was made of the emissions to the atmosphere both of methane and of other pollutants. An evaluation of the influence exerted by these measures on the performance of cogeneration of heat and electricity has been prepared. Several projects in progress are described, namely the increase of gas-firing in existing boiler installations, investment projects referring to the installation of gas engines for cogeneration of heat and electricity, utilization of the distribution network for the maximum utilization of gas and the designs of power-generation systems (using methane) for air conditioning in the mines.     

Statistical modeling of particles relative motion in a turbulent gas flow

On the base of modern probability approach the theoretical model of turbulent relative motion of particles in the turbulent flow is developed. Closed equation for probability density function of coordinates and velocities of two particles in turbulent flow is obtained. The system of equations for balance of mass, averaged velocities and intensities of turbulent chaotic motion of particles with account of correlated motion of particles are deduced. The closed expressions for intensity of relative chaotic motion between particles are obtained on the base of probability density function of particles displacement with correlation effects. The correlation functions, intensity of relative turbulent motion and relative diffusion coefficients of particles are numerically investigated. The calculation results are compared with data of large eddy simulations. The results of calculation intensity of droplets relative motion in atmospheric conditions are presented.     

Computer simulation of the performance of a solar pond in the southern part of Iran

In this study a computer model of a solar pond to be built in the southern part of Iran is developed. The input to the program is the daily solar radiation, ambient temperature, evaporation rate, etc. The temperature rise of the pond for various rates of energy removal is the output of the program. A parametric study on such a computer simulation for optimization of performance of the actual solar pond is quite economical. Several computer experiments are carried out for various conditions of interest of the area around Shiraz in the southern part of Iran. Temperature rise of the bottom of the pond is calculated for different rates of energy removal. It is observed that after a few months of operation, the temperature of the bottom of the pond becomes sufficiently high to allow energy extraction from the pond. The temperature variation of the pond for different overall efficiencies of the pond under various conditions are also obtained and discussed. The response of the pond to several consecutive days of cloudiness is also studied. It is concluded that solar ponds are also reliable solar collector-storage systems for this part of the world.     

管理激励在企业中的创新

为了探索符合时代发展要求的企业管理激励机制,首先从管理激励的必要性与重要性方面,探索了管理激励的一般理论;其次对上海易初通用公司实践的基础上,提出的具有操作性、创新性的企业管理激励机制新模式——M管理模式进行分析;第三,M管理模式的形成或思想来源,可以从当代经济理论与现代管理理论中找到其若干理论依据;最后,对上海汽车股份有限公司实施M管理模式的背景、具体做法、产生的效果及各界人士对M管理模式的评价进行了分析。实施M管理模式都取得了重大成果,表明M管理模式具有重要的推广价值。     

1992年夏季珠穆朗玛峰地区的太阳直接辐射和总辐射

用１９９２年夏季珠穆朗玛峰地区考察的多通道有线遥测辐射观测资料，对珠峰地区的太阳直接辐射和总辐射特征进行了研究。结果表明。１９９２年珠峰地区夏季中午前后的大气透明度状况与１９５９年没有明显差异。夏季在珠峰绒布寺地区最大总辐射大于太阳常数现象的出现十分频繁。本次考察时，在有完整资料的１６天中，１４天观测到了瞬时总辐射大于太阳常数的现象；这种现象从地方时９时到１４时都可出现，有时竟连续出现５个时欢。瞬时总辐射的最大值为１６８８Ｗｍ－２，超出了太阳常数２３％。考察期间记录到的总辐射时累计值的最大值为４．７１ＭＪｍ－２，平均强度１３０８Ｗｍ－２，达太阳常数的９５．７％。青藏高原地区持续出现总辐射大于太阳常数的现象对近地面辐射平衡及生态环境的影响尚有待进一步研究。     

U.S. oil dependence 2014: Is energy independence in sight?

The importance of reducing U.S. oil dependence may have changed in light of developments in the world oil market over the past two decades. Since 2005, increased domestic production and decreased oil use have cut U.S. import dependence in half. The direct costs of oil dependence to the U.S. economy are estimated under four U.S. Energy Information Administration Scenarios to 2040. The key premises of the analysis are that the primary oil market failure is the use of market power by OPEC and that U.S. economic vulnerability is a result of the quantity of oil consumed, the lack of readily available, economical substitutes and the quantity of oil imported. Monte Carlo simulations of future oil market conditions indicate that the costs of U.S. oil dependence are likely to increase in constant dollars but decrease relative to U.S. gross domestic product unless oil resources are larger than estimated by the U.S. Energy Information Administration. Reducing oil dependence therefore remains a valuable goal for U.S. energy policy and an important co-benefit of mitigating greenhouse gas emissions.     

Particulate formation in power station boiler furnaces

The review covers some of the more fundamental aspects of the production of particulate pollutants by fossil-fired power station boilers. The presence of soot is essential for efficient radiant heat transfer in oil-fired and to a lesser extent in p.f. fired boilers, in addition to its potential as a pollutant, thus its formation and burning has been intensively studied. Consequently, the section on soot is the most comprehensive section.Further less detailed sections deal with the nature of inorganic constituents of coals and oils burnt in C.E.G.B. power stations, cleaning of such fuels, ashes produced from the inorganic matter, and novel burning techniques which have recently been attracting extensive attention, for reducing the formation both of gaseous and particulate pollutants.Some interesting aspects of the potential interactions of particulate pollutants with gaseous ones are outlined. For instance, the reactions of compounds of alkali and alkaline earth metal in the form of fumes with oxides of sulphur, leading to the trapping of oxides of sulphur in deposits within the boiler is discussed. In addition, modification of combustion by recirculating flue gas through the coal mills in order to reduce pollutant formation would help to reduce the hazard of coal dust explosions in the burner feed pipelines.     

Mass and energy-capital conservation equations to study price evolution of non-renewable energy resources,Part III – Energy supply curve

The price evolution of non-renewable resources versus the consumption rate is investigated with the aim of constructing the energy supply curve. The case studied is without accumulation nor depletion of the resources and the mass and energy-capital conservation equations are solved under the condition of the same mass flow rate of extraction and sale. The energy supply curve of extracted resource is dependent on the newly defined parameter, RINE, Rate of Interest of Non-extracted resources on the Extraction rate. The energy supply curve of sold resource is dependent on the newly defined parameter, RISE, Rate of Interest of Sold resources on the Extraction rate, in case the rate of interest of non-extracted resources, r_N, is nil. In general, the energy supply curve of sold resource is dependent also on two dimensionless parameters, Dimensionless Critical Initial Price of Sold resources_, i.e. DCIPS, and Dimensionless Critical Initial Price Extreme of Sold resources, i.e. DCIPES. The energy supply curve of sold resources is investigated under different relations between three parameters, i.e. extraction rate and interest rates of non-extracted and extracted/sold resources. New trends are observed in the economic market of non-renewable energy resources. The energy supply curve of the difference between sold and extracted resource is also obtained and is dependent on two dimensionless parameters, Critical Initial Price Difference_, i.e. CIPD, and Critical Extreme of the Initial Price Difference, i.e. CEIPD. Finally, the predictions obtained with the present approach are compared to the real evolution of the world price of oil and the European price of gas versus the world consumption during the last three decades, i.e. from 1980 until 2005 for oil and from 1984 until 2005 for gas, taking into account inflation, discount and prime rates of the economic market. The agreement is acceptable but, more important, the trend is correctly predicted. The price difference between sold and extracted resources is also investigated versus the dimensionless mass flow rate of extraction. The evolution is dependent on four parameters: RINE, RISE, DCIPS, and DCIPES.     

Carbon materials in composite bipolar plates for polymer electrolyte membrane fuel cells: A review of the main challenges to improve electrical performance

The technology of polymer electrolyte membrane (PEM) fuel cells is dependent on the performance of bipolar plates. There is a strong relationship between the material used in the manufacturing of the bipolar plate and its final properties. Graphite-polymer composite bipolar plates are well-established commercial products. Several other carbon based fillers are tested. Carbon nanotubes, carbon fibers, carbon black, graphite nanoplatelets and expanded graphite are examples of such materials. Structural characteristics of these particles such as morphology and size have decisive influence on the final properties of bipolar plates. Furthermore, the volumetric fraction of the filler is of prime importance. There is plenty of information on individual aspects of specific composite bipolar plates in the literature. Notwithstanding, the analysis of structure-property relationship of these materials in a comprehensive source is not found. In this paper, relevant topics on the structural aspects of carbon based fillers and how they influence the final electrical performance of composite bipolar plates are discussed. It is intended that this document contribute to the development of new and maximized products to the PEM fuel cell industry.