乙醇汽油与普通汽油非常规污染物排放特性对比研究

在一台满足国Ⅴ排放标准的双喷射(气口喷射+缸内直喷)汽油机上开展了燃用E10乙醇汽油(乙醇体积比为10%)对发动机非常规排放特性影响的试验研究.使用傅里叶变换红外分析仪(FTIR)测量了饱和烃、不饱和烃、芳香烃及醇、醛等非常规污染物排放量,对比分析了双喷射模式时各工况下E0和E10两种燃料的非常规排放水平.结果表明,双喷射模式下,加入乙醇有效降低了乙烯、1,3-丁二烯、苯和甲苯的排放量,但会导致乙醛排放升高.双喷射模式下,随着负荷增加,两种燃料下的1,3-丁二烯和甲苯排放呈现先升高后降低的趋势,乙烯、甲醛和苯排放则先降低后升高.乙醇能抑制1,3-丁二烯、乙烯生成,抑制效果为PFI模式优于双喷射模式,GDI模式抑制量最低.PFI和GDI模式下E10的甲醛排放均显著升高,但双喷射模式有效抑制了甲醛排放的增加.     

Investigation to meet China II emission legislation for marine diesel engine with diesel methanol compound combustion technology

In order to reduce the pollutant emission and alleviate the pressure of petroleum resources shortage and greenhouse gas emission at the same time, the use of clean and renewable alternative fuel for marine engines is a promising option. In this study, a marine diesel engine, which was modified to run in diesel methanol compound combustion (DMCC) mode, was investigated. After the diesel injection parameters were calibrated, and combined with a sample after-treatment device DOC (diesel oxidation catalyst), the engine could meet the requirements of China II legislation. The overall MSP (methanol substitute percent) reached 54.1%. The value of each pollutant emission was much lower than that in China II emission legislation, and there was almost no methanol and formaldehyde emissions. When methanol was injected into the inlet manifold, the intake air temperature decreased a lot, as well as the exhaust gas temperature, which were beneficial to increase engine thermal efficiency and improve engine room environment. Compared with the engine running in pure diesel mode, when the engine ran in diesel/methanol dual fuel mode, the combustion phase was advanced, and the combustion duration became shorter. Therefore, the engine thermal efficiency increased, and fuel consumption decreased significantly.     

Potential of secondary aerosol formation from Chinese gasoline engine exhaust

Light-duty gasoline vehicles have drawn public attention in China due to their significant primary emissions of particulate matter and volatile organic compounds(VOCs). However,little information on secondary aerosol formation from exhaust for Chinese vehicles and fuel conditions is available. In this study, chamber experiments were conducted to quantify the potential of secondary aerosol formation from the exhaust of a port fuel injection gasoline engine. The engine and fuel used are common in the Chinese market, and the fuel satisfies the China V gasoline fuel standard. Substantial secondary aerosol formation was observed during a 4–5 hr simulation, which was estimated to represent more than 10 days of equivalent atmospheric photo-oxidation in Beijing. As a consequence, the extreme case secondary organic aerosol(SOA) production was 426 ± 85 mg/kg-fuel, with high levels of precursors and OH exposure. The low hygroscopicity of the aerosols formed inside the chamber suggests that SOA was the dominant chemical composition. Fourteen percent of SOA measured in the chamber experiments could be explained through the oxidation of speciated single-ring aromatics. Unspeciated precursors, such as intermediate-volatility organic compounds and semi-volatile organic compounds, might be significant for SOA formation from gasoline VOCs. We concluded that reductions of emissions of aerosol precursor gases from vehicles are essential to mediate pollution in China.     

柴油机尾气中PAH_s的分析

本文概述了柴油机尾气中ＰＡＨｓ的分析方法，着重论述了采样及预处理方法，特别对预处理方法进行了深入的探讨。另外，通过对柴油机两种不同工况下产生的尾气进行分析后发现，柴油机转速越高，其排放尾气中ＰＡＨｓ的含量就越低。     

Multipoint source method in air pollution modelling of cold start emission

The paper presents a new method of air pollution modelling on a micro scale. For estimation of concentration of car exhaust pollutants, each car is treated as an instantaneous moving emission source. This approach enables us to model time and spatial changes of emission, especially during cold and cool start of an engine. These stages of engine work are a source of significant pollution concentration in urban areas. In this work, two models are proposed: one for the estimation of emission after cold start of the engine and another for the prediction of pollutant concentration. The first model (defined for individual exhaust gas pollutants) enables us to calculate the emission as a function of time after the cold or cool start, ambient temperature and average speed of motion. This model uses the HBEFA database. The second mathematical model is developed in order to calculate the pollutant dispersion and concentrations. The finite volume method is applied to discretise the set of partial differential equations describing wind flow and pollutant dispersion in the domain considered. Models presented in this paper can be called short-term models on a small spatial scale. The results of numerical simulation of pollutant emission and dispersion are also presented.     

A comparison of hydrocarbons emission from engine running 85# gasoline and M-100 methanol fuel

Increasing global interest in methanoi fuel has led us to investigate the exhaust emissionsof its engine. Analysis of its inorganic and organic emissions. such as CO. NO_x and hydrocarbons(total HC) have been widely reported. This paper presents an analysis of more than 20 kinds ofhydrocarbons in the emissions obtained from a spark-ignition Shanghai car running 85^# gasoline anda comparison with emission from a Santana test car running M-100 methanol fuel. A set ofenrichment method has also been described. Test results show that at the current stage of methanolengine development the concentration of individual hydrocarbon including some poisonous substancesis lower than those of normal gasoline engine.     

船舶柴油机NOx后处理技术的进展

根据国内外的降低NOx排放方面最新的成果和科研动态，主要介绍了当前正在研究或者已经应用于实际的有效降低柴油机NOx排放的技术措施，并分析了各种技术方法的特点和在实际应用过程中面临的问题。     

柴油发动机隔振方面的仿真研究

本文主要研究模糊控制技术在柴油发动机隔振系统中的应用，将模糊控制技术引入柴油发动机隔振主动控制系统，针对柴油发动机隔振模拟实验台架的振动特点，建立了控制系统数学模型，进行了柴油发动机隔振模拟实验台架垂直方向的仿真研究。     

柴油汽车掺烧LPG降低黑烟排放技术

研究了柴油机掺烧液化石油气(LPG)以降低黑烟排放的技术方案，并开发出了一种以独特型板调节装置为特征的机械控制式柴油/LPG双燃料供给系统。发动机不改变原有结构加装该系统后即成为柴油/LPG双燃料发动机，可以同时燃烧柴油和LPG两种燃料，并且在整个工作范围内，随着工况变化能够按照预先优化设定的型板型线规律而自动调节柴油／LPG供给量比例，使烟度降低50％以上，同时满足经济性、动力性以及操作性能等要求，此外，也可以切换为单独燃烧柴油，而不改变发动机的原有性能。该系统结构简单、成本低廉，非常适合于改装城市在用公交车，降低其黑烟排放。     

高原铁路机车乘务人员生理选拔指标研究

为了研究高原铁路机车乘务员生理选拔指标,确定生理指标鉴定标准值,选择西宁铁路分局西格段机车司机500人进行指标体系鉴定试验。其结果表明:西格段机车司机总体合格率为31.6%,年龄、行车线路高度差对合格率有较大影响;确认红细胞压积、白细胞计数、血小板计数、血氧饱和度、血糖、谷草转氨酶、总胆红素、直接胆红素、尿蛋白和尿红细胞为较敏感的高原低氧生理代偿指标;可作为生理适应性筛检指标。提出选拔青藏铁路机车乘务员应采用基础体检、高原适应性体检二级结构模型;制定了高原机车乘务员体检鉴定医学标准、测试方法、合格判定标准。