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′.     

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.     

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.     

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.     

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.     

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)     

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.     

Investigation of the temperature oscillations in the cylinder walls of a diesel engine with special reference to the limited cooled case

This work investigates the interesting phenomenon of the temperature (cyclic) oscillations in the combustion chamber walls of a diesel engine. For this purpose, a comprehensive simulation code of the thermodynamic cycle of the engine is developed taking into account both the closed and the open parts of it. The energy and state equations are applied, with appropriate combustion, gas heat transfer, and mass exchange with the atmosphere sub‐models, to yield cylinder pressure, local temperatures and heat release histories as well as various performance parameters of the engine. The model is appropriately coupled to a wall periodic conduction model, which uses the gas temperature variation as boundary condition throughout the engine cycle after being treated by Fourier analysis techniques. It is calibrated against measurements, at various load and speed conditions, from an experimental work carried out on a direct injection (DI), naturally aspirated, four‐stroke, diesel engine located at the authors' laboratory, which has been reported in detail previously. After gaining confidence into the predictive capabilities of the model, it is used to investigate the phenomenon further, thus providing insight into many interesting aspects of transient engine heat transfer, as far as the influence that engine wall material properties have on the values of cyclic temperature swings. These swings can take prohibitive values causing high wall thermal fatigue, when materials of specific technological interest such as thermal insulators (ceramics) are used, and may lead to deterioration in engine performance. Copyright © 2004 John Wiley & Sons, Ltd.     

车用汽油机废气涡轮增压存在障碍及对策

本文简要介绍了汽油机废气涡轮增压的，重点分析了汽油机废气涡轮增压存在的障碍，即汽油机增压易发生爆燃、汽油机增压热负荷大、汽油机与增压器匹配困难等及解决障碍的措施。     

高性能中速柴油机开发可行性分析

本文主要介绍国外中速柴油机的发展情况及我国中速柴油机的状况,简单介绍了国外中速柴油机发展所采取的技术措施,论证了国产高性能中速柴油机的意义及可行性。     

运转参数对双燃料发动机性能影响的预测

文中模拟计算了运转参数如进气温度、喷油定时等对双燃料发动机性能的影响,简要分析了改善发动机性能的措施。结果表明,燃用双燃料需适当提前喷油;而缸内存在适当涡流,有益于提高输出功率。     

Experimental study of the effect of fuel types on the performance of spark ignition engine

Different fuels are being used daily in the city of Kirkuk, Iraq for operating vehicles with spark-ignition internal combustion engines. Aiming to address the effects of these fuels on both engines and the environment, this work conducts an experimental study where a single-cylinder, four-stroke small spark ignition engine is employed. Three types of benzene with different octane ratings (low with an additive [85.8%], medium [89.2%], and high [95.6%]) are utilized in the study as they are the most consumed fuel in the area of the study. Moreover, the low-octane fuel will be addressed with a commercial additive. In addition to engine performance, the exhaust gases and sound levels are analyzed as well. Through the outcomes, it is observed that the fuel with higher octane numbers relatively produces better engine performance and pollution. At normal engine speed, the fuel with a medium octane rating, however, has close engine performance results but with worse pollution effects. On the other hand, the engine fails to start with low-octane fuel without the additive. The additive improves the engine performance with the low octane fuel and surprisingly produces fewer pollution gases than the fuel with medium octane number. However, the engine still behaves worse than with the other fuels at normal engine speed.     

微燃烧发动机应用于微型飞行器的性能分析

阐述了目前微燃烧发动机的研究进展．以现有的材料和加工技术,微燃烧发动机的实现是完全可行的．对比评价了微燃烧发动机和锂电池两种微型飞行器动力源的航程、续航时间和飞行机动性等性能．结果表明,采用微燃烧发动机的飞行器航程最高可达到相同条件下普通锂电池飞行器的29．5倍,续航时间可达到普通锂电池飞行器的39倍,并且微燃烧发动机能大大提高飞行器的飞行机动性．     

CA6102汽油／LPG双燃料发动机动力性能的研究

为了解决解放CA6102发动机改装双燃料后动力性下降的问题,作者对LPG供气系统,点火系统,进气系统和燃烧系统进行了改进和优化,在不影响发动机经济性和排放的情况下,以实现发动机燃用LPG理动力性能下降不超过5％的目的。     

船舶柴油机载荷测试技术应用分析

应用船舶柴油机载荷测试技术,在固定航线上进行船舶柴油机载荷测试试验,为确定主机运行状态及船舶运营状态提供有效试验数据。实船测试及应用情况表明:船舶柴油机载荷测试技术可对船舶的船、机、桨匹配性以及船舶运营的经济性状态做出有效的评价,可为后续船舶柴油机产品性能优化、技术营销等提供依据。     

The impact of heat exchanger fouling on the optimum operation and maintenance of the Stirling engine

This paper focuses on the effect of heat exchanger fouling on the performance of the Stirling engine in combined heat and power (CHP) application. Fouling results from using biomass fuels and affects the heat exchanger that transfers heat into the engine. This heat exchanger is referred to as the heater. The heat exchanger that recovers heat from the flue gases is also affected by fouling. To determine the performance of the Stirling engine, a commercial Stirling analysis tool is applied together with models that have been developed for the heat transfer in the heater, regenerator and cooler of the engine. The Stirling engine model uses constant temperatures for the heat addition and rejection, with the theory of displacement engine as a basis. The fouling in the heat exchanger is taken into account by using a fouling factor that corresponds with the degradation in the total heat transfer coefficient. The Stirling engine model together with the model for heat exchanger fouling makes it possible to estimate the effect of fouling on the performance of the Stirling engine. A cost model is developed for the engine to translate changes in performance into economy in CHP operation. In the studied application, the Stirling engine is operated by the heat demand. Together with the selected control method, performance and cost models compose a tool for the simulation and optimization of the system. The use of the models to determine the optimal cleaning interval of the heat exchanger surfaces is considered.     

生物能利用技术探讨

能源开发格局，动力机的系统结构对人类社会的发展起着至关重要的作用，以石油为主的第三代能源正面临着枯竭的危险，生物能作为一种储量丰富．可经济开发的清洁能源越来越受到人们的重视。作为动力机主力军的内燃机也在经受能源危机、环境的考验，鉴于目前状况，从生物技术和仿生技术的角度，结合生物质能的开发利用途径，提出了生物动力机这个概念，并对其做了较为详细的限定描述，阐明了生物动力机和内燃机的本质区别，分析了生物动力机的优点和开发途径。