冷静对待热点

内燃机排放这个技术热点，经过一个漫长的冷清，终于成为社会热点。虽然“来迟了”，但总比不来好。人们虽然更多地从汽车尾气排放认识它，但总比不认识好。在“运动”惯了的中国，它又象“运动”起来了．在“浮躁”流行的今天，又似乎看到了“浮躁”．“有关部门齐出动”，“高标准”， “严要求”，“砸车毁机”，好不热闹，一夜间一批车辆和动力突然变“绿”，绿得让人难以理解． 我们曾千呼万唤，我们曾千期万盼，希望“有关方面”，把这项工作提到日程上，放到议程中，并及早付诸行动。唤来了，盼来了，然而，面对今天的现实，想想还是…     

焦化气发电技术的应用

兖州矿业(集团)公司焦化厂利用剩余的煤气作能源，建立了焦化厂自备电站发电自用，减少了环境污染，降低了生产成本，保护了生态环境，取得了较好的经济效益和社会效益。     

YC6108ZQ 4气门柴油机的开发及性能研究

根据YC6108ZQ柴油机的结构特点和工艺性要求，确立了4气门柴油机气门和气道的布置方案，气门尺寸和位置，选定了气道参数，设计了4气门柴油机气缸盖和摇臂机构，重新匹配了燃烧系统与供油系统，开发成功了YC6108ZQ4气门柴油机。发动机台试验结果表明，该4气门柴油机的功率提高了9%，最大转矩提高了12.7%，柴油机的经济性能有较大程度的改善，燃油经济区域的工况范围扩大，最低燃油消耗率降低。开发的4气门柴油机能够满足亚洲I号排放标准的要求，尤其是CO和NOx排放降低效果明显。所开发成功的YC6108ZQ4气门柴油机进气系统，供油系统和燃烧系统等匹配较好，达到了良好的燃烧效果，其动力性，经济性和排放水平达到了较高的水平。     

赞美太阳神

赞美太阳神姚彭生你洒向大地万丈光芒你是众神之神，你是众神之神，有了你，地球上才有风云变幻，有了你，才有生命发祥、万物生长，有了你，地球上才有能源矿藏，有了你，地球上才有绿色植物，有了你，才有粮食增产，丰收在望，有了你，地球上才有热源光亮。啊，太阳神啊...     

弹塑性本构模型研究及在燃气轮机叶轮中应用

弹塑性本构模型的研究是一门关于材料处于弹塑性变形状态下其应力－奕变关系的科学，它在能源工程中得到了广泛应用，国内外学者对此进行了大量研究，以此为基础通过值计算，完成了一系列能源装置的强度和变形分析，但尚存在不足之处，在以往的有关模型中，当应力处于特殊的状态下时，本构模型的算式失去意义，这直接影响了结构设计的可靠性，本文提出了解决方法，并将其用于燃气轮机叶轮的应力分析，得到了有用的结论。     

螺旋鳍片管束传热与阻力特性研究的现状与发展

螺旋鳍片管束因具有一系列优点，在常规锅炉及余热锅炉中得到了广泛的应用，为此，国内外有关学者对其传热与和特性进行了长期的研究，并取得了大量的成果，但是，因各种原因，现有研究成果存在局限性，不能满足实际需要，根据对现有成果的分析与比较，指出了有待进一步研究之处。     

卷烟厂空调系统节能控制策略的研究及应用

针对空调系统巨大的节能空间，进行节能控制策略的研究和应用，并对应用效果在理论上进行分析。实际运行结果表明，节能控制策略的应用，满足了工艺的温湿度要求，减少了能源浪费，降低了生产成本，取得了良好的效果。     

大峡水电站的控制爆破施工

大峡水电站工程施工中应用控制爆破技术，采取多钻孔，多分段，分散装药的措施，对处于环境条件复杂、干扰大的部位进行了拆除和爆破，有效地保护了附近建筑物及其它设施，使邻近工作面未受干扰，缩短了工期，为后续工序的提前进行创造了条件。     

标准化与企业的生存和发展

为了发展社会主义商品经济．促进技术进步，改进产品质量，提高社会和企业经济效益，维护国家和人民的利益，使标准化工作适应社会主义现代化建设和发展对外经济关系的需要，国家制定了标准化法。以法律的形式确定了标准化工作的地位和重要性，对各行各业、对企业和个人明确了其法律责任，对违法者必予以追究。国家及有关部门制定了各种各样的标准，从而保障了人民生命财产的安全，保护了消费者的利益，保护了环境。使国家资源能合理地利用，科学技术成果得到了推广，提高了经济效益，使许多产品能通用互换，做到了技术上先进，经济上合理，…     

ASP在城市燃气信息管理系统中的应用

主要阐述了ASP在城市燃气信息系统中的应用，介绍了ASP提供的动态面面技术，详细论述了使WebServe与后端数据库结合的关键技术及方法方法，从而使在WEB上对数据库进行增，删，改，查操作成为可能，也介绍了利用ASP实用户安全管理，口令管理，关键字检索等功能。     

燃料电池船舶舱内氢气泄漏爆炸的数值模拟研究

以燃料电池客船“Water-Go-Round”号为对象,利用FLUENT软件模拟燃料电池客船舱内管道发生氢气泄漏并引发爆炸的情况,研究不同舱室氢气点火爆炸事故的影响规律。结果表明：可燃氢气云被点燃后,爆炸超压波自点火位置向四周迅速传播,点火位置对超压波的分布影响较大;控制舱爆炸时,超压强度最大,对船体超压危害最大;乘客舱爆炸强度最小,但超压中心分布在乘客舱,超压对乘客造成的危害最大;船舶舱室燃烧火焰温度主要由可燃氢气云的分布决定,燃料电池舱的火焰衰减趋势基本相同;乘客舱受到的高温危害较低,船艏舱无燃烧火焰的高温危害。     

Identifying the Effect of Tidal Height on Offshore Wind Speed Profiles

The rise and fall of the sea surface due to the tide effectively moves an offshore wind turbine hub through the wind shear profile. Offshore wind farms are being built around the coasts of Europe, including in the Baltic and the North Sea. Tidal ranges in the North Sea are greater than those in the Baltic, and the potential effect on the wind shear profile of the change in sea surface height is likely to be more significant. This article seeks to identify the effect of tidal height on the shear profile at a mast off the east coast of the UK where the maximum tidal range is 7 m. Definite evidence for the effect of tidal height on wind shear is presented, though the effect is small and there is considerable scatter in the data. Copyright © 2003 John Wiley & Sons, Ltd.     

Effect of cellulose and lignin content on pyrolysis and combustion characteristics for several types of biomass

Fundamental pyrolysis and combustion behaviors for several types of biomass are tested by a thermo-gravimetric analyzer. The main compositions of cellulose and lignin contents for several types of biomass are analyzed chemically. Based on the main composition results obtained, the experimental results for the actual biomass samples are compared with those for the simulated biomass, which is made of the mixture of the cellulose with lignin chemical. The morphological changes before and after the reactions are also observed by a scanning electron microscope. The main compositions in the biomass consisted of cellulose and lignin. The cellulose content was more than lignin for the biomass samples selected in this study. The reaction for the actual biomass samples proceeded with the two stages. The first and second stage corresponded to devolatilization and char combustion during combustion, respectively. The first stage showed rapid mass decrease caused by cellulose decomposition. At the second stage, lignin decomposed for pyrolysis and its char burned for combustion. For the biomass with higher cellulose content, the pyrolysis rate became faster. While, the biomass with higher lignin content gave slower pyrolysis rate. The cellulose and lignin content in the biomasses was one of the important parameters to evaluate the pyrolysis characteristics. The combustion characteristics for the actual biomass depends on the char morphology produced.     

Theory and experimental investigation of a weir-type inclined solar still

A weir-type solar still is proposed to recover rejected water from the water purifying systems for solar hydrogen production. This consists of an inclined absorber plate formed to make weirs, as well as a top basin and a bottom basin. Water is flowed from the top basin over the weirs to the bottom collection basin. A small pump is used to return the unevaporated water to the top tank. Hourly distillate productivity of the still with double- and single-pane glass covers was measured and the latter showed higher production rates. The average distillate productivities for double- and single-pane glass covers are approximately 2.2 and 5.5 l/m²/day in the months of August and September in Las Vegas, respectively. Mathematical models that can predict the hourly distillate productivity are developed. These compared well with the experimental results. Productivity of the weir-type still with a single-pane glass was also compared with conventional basin types tested at the same location. The productivity of the weir-type still is approximately 20% higher. The quality of distillate from the still is analyzed to verify the ability of the still to meet the standards required by the electrolyzers.     

可变偏心距风力机应力应变特性研究

针对新型可变偏心距风力机,通过数值模拟及实验测试的方法,研究偏心距离对风轮、塔筒及侧偏调节机构受力的影响。结果表明,在来流风速增大的条件下,可变偏心距风力机通过增大偏心距可减小叶片受力,风轮向右侧偏心100 mm时叶片最大应力是未偏心工况的86%;随着偏心距离的增大,塔筒在俯仰方向受力增长趋势放缓,受风轮偏转角增大的影响,塔筒在侧弯方向受力处于持续增大的状态;在向右偏心距离增大的过程中,风轮侧偏调节机构应力及应变逐渐向右侧集中,最大应力、应变始终处于中间部位,结果验证了偏心距调节方式的可行性及安全性。     

Dendritic heat convection on a disc

In this paper we develop the optimal tree-shaped flow paths for cooling a disc-shaped body by convection. Heat is generated uniformly over the disc area. The coolant enters through the center of the disc, and exits through ports positioned equidistantly along the perimeter. The unknown is the flow architecture. The constraints are the disc size and the total volume occupied by the ducts. It is assumed that the ducts are narrow enough so that the flow is hydrodynamically and thermally fully developed. The ultimate goal is to determine flow architectures that reach simultaneously two objectives: (i) minimal global fluid flow resistance (or pumping power), and (ii) minimal global thermal resistance. When the architecture is optimized for (i), the result is a dendritic structure in which every geometric feature is uniquely determined. The corresponding thermal resistance decreases as the total mass flow rate and the pumping power increase. When the objective is (ii), the optimal architecture has radial ducts, not dendrites. The corresponding fluid-flow resistance increases as the flow rate increases and the global thermal resistance decreases. Put together, these geometric results show that methods (i) and (ii) lead to nearly the same combined performance (thermal and fluid). Examined more closely, the dendrites produced by method (i) perform progressively better as the length scales become smaller. Optimized increasing complexity is the route to high thermal and fluid-flow performance in the limit of decreasing scales.     

Simulation of small-scale releases from liquid hydrogen storage systems

Knowledge of the concentration field and flammability envelope from small-scale leaks is important for the safe use of hydrogen. These small-scale leaks may occur from leaky fittings or o-ring seals on liquid hydrogen-based systems. The present study focuses on steady-state leaks with large amounts of pressure drop along the leak path such that hydrogen enters the atmosphere at near atmospheric pressure (i.e. Very low Mach number). A three-stage buoyant turbulent entrainment model is developed to predict the properties (trajectory, hydrogen concentration and temperature) of a jet emanating from the leak. Atmospheric hydrogen properties (temperature and quality) at the leak plane depend on the storage pressure and whether the leak occurs from the saturated vapor space or saturated liquid space. In the first stage of the entrainment model ambient temperature air (295 K) mixes with the leaking hydrogen (20-30 K) over a short distance creating an ideal gas mixture at low temperature (∼65 K). During this process states of hydrogen and air are determined from equilibrium thermodynamics using models developed by NIST. In the second stage of the model (also relatively short in distance) the radial distribution of hydrogen concentration and velocity in the jet develops into a Gaussian profile characteristic of free jets. The third and by far the longest stage is the part of the jet trajectory where flow is fully developed. Results show that flammability envelopes for cold hydrogen jets are generally larger than those of ambient temperature jets. While trajectories for ambient temperature jets depend solely on the leak densimetric Froude number, results from the present study show that cold jet trajectories depend on the Froude number and the initial jet density ratio. Furthermore, the flammability envelope is influenced by the hydrogen concentration in the jet at the beginning of fully developed flow.     

Performance assessment of some ice TES systems

In this paper, a performance assessment of four main types of ice storage techniques for space cooling purposes, namely ice slurry systems, ice-on-coil systems (both internal and external melt), and encapsulated ice systems is conducted. A detailed analysis, coupled with a case study based on the literature data, follows. The ice making techniques are compared on the basis of energy and exergy performance criteria including charging, discharging and storage efficiencies, which make up the ice storage and retrieval process. Losses due to heat leakage and irreversibilities from entropy generation are included. A vapor-compression refrigeration cycle with R134a as the working fluid provides the cooling load, while the analysis is performed in both a full storage and partial storage process, with comparisons between these two. In the case of full storage, the energy efficiencies associated with the charging and discharging processes are well over 98% in all cases, while the exergy efficiencies ranged from 46% to 76% for the charging cycle and 18% to 24% for the discharging cycle. For the partial storage systems, all energy and exergy efficiencies were slightly less than that for full storage, due to the increasing effect wall heat leakage has on the decreased storage volume and load. The results show that energy analyses alone do not provide much useful insight into system behavior, since the vast majority of losses in all processes are a result of entropy generation which results from system irreversibilities.     

Extended Oberbeck-Boussinesq approximation study of convective instabilities in a porous layer with horizontal flow and bottom heating

A study of the onset of convective instabilities in a porous layer with a horizontal basic flow is performed by including the effects of viscous dissipation and pressure work in the energy balance. Firstly, the so-called extended Oberbeck-Boussinesq approximation, i.e. the model based on the enthalpy formulation of the energy balance, is adopted. Then, the results for the marginal stability condition are compared with those obtained by the so-called Chandrasekhar approximation, i.e. the model based on the internal-energy formulation of the energy balance. It is shown that a marked discrepancy occurs between the two approaches, that becomes specially evident for high values of the Gebhart number. According to the extended Oberbeck-Boussinesq approximation, the effects of the viscous dissipation and of the pressure work result in a stabilization of the basic flow. On the contrary, the Chandrasekhar approximation predicts a destabilization of the basic flow induced by the viscous dissipation. The destabilization can be so intense that the onset of convective rolls may occur even in the absence of a boundary temperature difference, i.e. with a vanishing Darcy-Rayleigh number.