发动机台架模拟汽油车冷启动排放特性研究

在发动机模拟实验台架上研究了采用不同的催化转化器和不同布置方案的后处理系统对低温启动过程中排放特性的影响。研究结果表明：-7℃冷启动过程中,催化转化器前移、选用较高活性的催化转化器和加装前级催化转化器都会不同程度地降低冷启动排放。其中采用低起燃温度催化转化器近距离布置,可以使两循环内的THC（总HC排放物）排放量减少约38％;采用两级催化转化器,可使THC排放量减少约47％。     

码头作业费问题的法律分析

立足我国航运竞争法的相关法律法规,从法律的角度对码头作业费问题做了实证分析,最后得出了班轮公司收取码头作业费并不违法的结论。     

论码头作业费纠纷的法律性质

有关码头作业费的纠纷在中国已经持续了四年多,自宣布收取该费用之日始,它就一直是航运界的热点问题。最近负责调查此事的有关部门作出了最终的调查结论,但并未对问题做出充分的解释和说明,以至于没能彻底解决班轮公会到底能否向货主收取码头作业费这一关键问题。本文试图通过对码头作业费纠纷法律性质的分析,为解决码头作业费的收取问题奠定基础。     

在发动机台架上模拟欧Ⅲ低温冷启动排放特性的探索

为使汽油车满足欧Ⅲ排放法规，必须解决-7℃条件下的催化器快速起燃和抑制排放物陡增的问题。作者研究设计了试验系统和探讨了模拟方法，并在台架上模拟和测试带有三效催化器的汽油车电喷发动机的低温启冷动特性。     

基于AT89S52和TLC0834的数据采集系统

基于单片机的数据采集系统在工业控制和实验室研究方面的应用相当广泛,模数转换是以单片机为核心的数据采集系统中关键环节之一。本文介绍了AT89S52单片机和串行A/D芯片TLC0834的主要特点,设计了基于AT89S52单片机和串行A/D芯片TLC0834接口电路并利用C语言进行了软件程序设计。该系统适用于多种数据采集场合,支持ISP技术,具有精度高、速度陕、体积小的特点。     

Combustion stability analysis during engine stop and restart in a hybrid powertrain

A cycle-resolved analysis system was designed with the specified measurement instruments to investigate the characteristics of combustion stability in a mild gasoline hybrid powertrain. A Fast Response Flame Ionization Detector (FFID), cylinder pressure transducer and engine torque transducer were used to observe both the engine-out THC emissions and engine performance during a brief moment of engine restart. This research aimed to improve combustion stability and was performed by varying the battery State Of Charge (SOC), injection duration and ignition timing. The results indicate that engine combustion tends to be more stable with longer fuel injection durations and advanced ignition timing, while the effect of the battery SOC is negligible. Also, peculiar differences in the catalyst conversion efficiency at the front and rear of the catalyst during engine restart and deceleration were revealed, with the degree of HC oxidation being the suspected cause. This study not only analyzed the engine control and engine-out total hydrocarbon (THC) emission characteristics, but also implemented control strategies that allowed for combustion stability during engine stop and restart operation.     

Isocyanic acid and ammonia in vehicle emissions

Vehicles are considered to be an important source of ammonia (NH₃) and isocyanic acid (HNCO). HNCO and NH₃ have been shown to be toxic compounds. Moreover, NH₃ is also a precursor in the formation of atmospheric secondary aerosols. For that reason, real-time vehicular emissions from a series of Euro 5 and Euro 6 light-duty vehicles, including spark ignition (gasoline and flex-fuel), compression ignition (diesel) and a plug-in electric hybrid, were investigated at 23 and −7 °C over the new World harmonized Light-duty vehicle Test Cycle (WLTC) in the Vehicle Emission Laboratory at the European Commission Joint Research Centre Ispra, Italy. The median HNCO emissions obtained for the studied fleet over the WLTC were 1.4 mg km⁻¹ at 23 °C and 6 mg km⁻¹ at −7 °C. The fleet median NH₃ emission factors were 10 mg km⁻¹ and 21 mg km⁻¹ at 23 and −7 °C, respectively. The obtained results show that even though three-way catalyst (TWC), selective catalytic reduction (SCR), and NOx storage catalyst (NSC) are effective systems to reduce NOx vehicular emissions, they also lead to considerable emissions of the byproducts NH₃ and/or HNCO. It is also shown that diesel light-duty vehicles equipped with SCR can present NH₃ emission factors as high as gasoline light-duty vehicles at both, 23 and −7 °C over the WLTC. Therefore, with the introduction in the market of this DeNOx technology, vehicular NH₃ emissions will increase further.