火花点火式天然气发动机燃烧系统的研究

本介绍了天然气发动机预燃室燃烧系统的研制过程，新设计的燃烧系统工作可靠、性能优良。试验结果表明：预燃室内混合气着火稳定、火焰传播迅速；主燃室燃烧速度高、持续期短、无后燃现象，整机性能比原机有较大的提高。     

A guide to the Kyoto protocol: a treaty with potentially vital strategic implications for the renewables industry

Why should renewables advocates care about the arcane business of multilateral climate negotiations? The answer is simple. Because these long-running and oft bogged-down talks have as their ultimate objective a goal with seismic implications for energy markets: substantial reductions in greenhouse gas emissions. Coming anywhere close to that goal would entail the creation of multi-hundred billion dollar markets in renewables in the years ahead. And in Kyoto last December, governments took a meaningful first step in that direction.This paper is a brief summary, and analysis of that first step. It concludes with some observations about immediate implications for the renewables industries.     

Expanding electricity capacity in Thailand to meet the twin challenges of supply security and environmental protection

Rapid growth in electricity demand in Thailand is a major challenge for electric utilities trying to ensure adequate supply. Continued reliance on natural gas for power supply makes the supply mix non-diversified and exposes the country to supply risks while a diversification to other fossil fuels imposes additional environmental burdens. To find an acceptable solution to this twin challenge, this paper assesses four scenarios of electricity capacity expansion planning for Thailand for the period between 2011 and 2025 under two different assumptions of fuel prices to reflect the case of international high oil price affecting cost of fuels for power generation in Thailand. It is found that the lowest environmental emissions are obtained from the scenario where power generation is highly dominated by natural gas. In contrast, the least cost electricity generation is achieved from the case if nuclear power plant is added into the Thai power system. Reliance on natural gas for power generation increases the spending on gas purchase as a share of the gross domestic product (GDP)—between 2.38% and 3.61% of (GDP). In addition, fuel import dependence, particularly for natural gas and coal, increases exposing the country to possible price volatility.     

排气门正时对柴油机冷起动性能的影响

通过在一台单缸直喷柴油机上进行实验,分析了不同排气门正时条件对柴油机冷起动过程燃烧及排放性能的影响.结果表明,通过调节排气门关闭正时,适当增大缸内残余废气量,可显著改善起动过程初始着火循环的着火燃烧性能和提高起动过程缸内燃烧的稳定性.不同排气门关闭条件对起动过程的排放有着非常重要的影响.适当提前排气门关闭时刻,可以显著降低冷起动过程的烟度排放,特别是降低冷起动过程初始阶段的烟度排放.而对于NO2排放,由于残余废气具有很强的热效应,随着排气门关闭时刻提前,Nox排放呈上升趋势.     

石化企业烟气脱硫技术及选择

介绍了石化企业常用的脱硫技术,并分析了各技术的优缺点。分析了石化企业烟气SO2排放及脱硫现状,指出石化企业在选择烟气脱硫技术时需考虑的因素有：企业所处地理环境和SO2排放要求,锅炉规模、建设年限及燃料结构,脱硫剂市场情况及品质要求,脱硫副产物利用情况,脱硫装置运行成本等。提出了有关石化企业减少SO2排放和烟气脱硫技术选择的建议。     

Semi-analytical proton exchange membrane fuel cell modeling

Mathematical techniques are presented which allow for analytical solutions of the catalyst layer transport and electrochemical problem in PEM fuel cells. These techniques transform the volumetric reaction terms to boundary flux terms, thereby eliminating the need for computational solving of the catalyst layer problem. The result is a semi-analytical fuel cell model—a computational model that entails analytical rather than computational catalyst layer solutions. This helps to alleviate the meshing difficulties inherent in the catalyst layers caused by large geometric aspect ratios, and hence reduce the computational requirements for fuel cell models.     

Experimental study of effect of hydrogen addition on combustion of low caloric value gas fuels

The effect of hydrogen on the premixed combustion of low calorific value gas in cylinder was carried out. The engine bench test system was built, and the effects of hydrogen on the pressure in cylinder, the characterization parameters of flame stability, flame shape, combustion cycle variation, flame surface structure and development were studied. The experimental results show that adding hydrogen to low calorific value gas fuels can increase laminar flame propagation rate, increase heat release rate, improve engine volumetric efficiency and reduce engine cycle variation. With the increase of hydrogen fraction, the maximum cylinder pressure of the engine rises, the corresponding crankshaft angle moves forward, and the flame development period and the rapid combustion period of the engine working cycle are reduced. The flame propagation rate of hydrogen blended low calorific value gas is larger, which enhances the strength of the vortex blob in cylinder to some extent. The increase of hydrogen fraction in mixture increases the flame propagation velocity, and enhances the effect of the combustion process on vortex intensity in cylinder, which increasing the effect of vortex blob on the flame surface structure. With the increase of hydrogen fraction, the vortices of the flow field in the cylinder increase, the time of which the flame surface reaches the same fold is in advance, and the flame development period is shortened.     

火电厂NOX污染排放控制方法探讨

NOx的排放控制将是火电厂未来环境保护的重要任务，减少NOx排放的一些方法。     

济钢顶燃式热风炉烟气分布研究

运用CFD软件对卡鲁金热风炉和ZSD热风炉的气体燃烧和流动进行了数值模拟,得到燃烧室出口烟气速度的分布,并对卡鲁金热风炉燃烧室出口烟气的压力和温度分布进行了测试,分析了两种炉型燃烧室的结构特点。结果表明,卡鲁金热风炉燃烧室出口烟气分布的均匀程度大大高于传统的ZSD热风炉,其结构特点对ZSD热风炉的改造有很大的参考价值。     

不同点火时刻下天然气掺氢缸内直喷发动机燃烧与排放特性

在缸内直喷火花点火发动机上开展了天然气掺混0％-18％氢气的混合燃料不同点火时刻下的试验研究。结果表明：对于给定的喷射时刻和喷射持续期,点火时刻对发动机性能、燃烧和排放有较大影响,喷射结束时刻与点火时刻的间隔对直喷天然气发动机极为重要,喷射结束时刻与点火时刻的间隔缩短时,混合气分层程度高,燃烧速率快,热效率高。最大放热率等燃烧特征参数随点火时刻的提前而增加。HC排放随点火时刻的提前而下降,CO2和NOx排放随点火时刻的提前而增加,NOx排放的增加在大点火提前角下更明显。掺氢可降低HC排放,对CO和CO2排放影响不大。掺氢量大于10％时可提高天然气发动机热效率。