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广州市公交车行驶工况与ETC城市工况的比较 总被引:2,自引:0,他引:2
为探讨重型汽车型式认证排放检测工况欧洲瞬态循环ETC工况与城市公交车实际行驶工况的符合性,对两辆典型的大型LPG公交车,沿广州市中心区两条典型公交线路运行,进行了公交车城市行驶逐秒的车速与变速挡位的测试,基于测试数据计算出对应的发动机转速与转矩,并将其与ETC城市工况比较.结果表明,相比ETC城市工况,LPG公交车实际运行工况中发动机怠速时间占比大1.4倍,零转矩占比大0.8倍,平均转速低38.34%,平均转矩低59.09%.在转速分布方面,实际行驶工况主要集中在低转速区,而ETC城市工况则主要分布在中、高转速区;至于转矩分布,实际行驶工况主要集中在低转矩区,而ETC循环则比较宽广地分布在整个转矩范围.总之,LPG公交车实际运行工况与ETC城市工况存在较明显的差异. 相似文献
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2012年8月7日环保部发布了制定国家环境保护标准《车用压燃式、气体燃料点燃式发动机与汽车冷启动排气污染物排放限值及测量方法》的通知,拟定2013年开始实施.因为现在执行的标准GB17691-2005《车用压燃式、气体燃料点燃式发动机与汽车排气污染物排放限值及测量方法》中的新车型式核准测试循环ETC对城市公交车(或城市车辆)的低速、低负荷工况不具备代表性,使得企业开发机型时基本没有考虑低速、低负荷的城市工况,导致城市车辆实际运行时尤其在低温工况时氮氧化物(NOx)排放严重超标,所以冷启动排放标准中可以考虑加入全球统一的重型发动机试验循环(World Harmonized Transient Cycle,WHTC),以完善标准GB17691-2005中ETC测试循环在低速、低负荷工况的缺陷. 相似文献
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分析了轻型车的排放转鼓循环试验和发动机台架试验之间的差异,进行了BJ1033轻型车转鼓试验和它装配的2.5 L排量4缸增压中冷柴油机台架试验,探讨了整车和发动机的CO,HC,NOx排放随时间和工况的变化关系。提出了整车排放分担率的指标,用整车分担率和发动机分担率表征各整车运行工况和发动机工况对排放的贡献。建立了整车运行工况与发动机台架试验工况之间的联系,运用灰色关联理论,分析了整车排放试验十五工况与发动机排放台架试验十三工况之间的关联度。结果表明:整车循环中,长时间的中高车速及加速工况下的排放分担率大;发动机台架试验中,中高转速、中高负荷工况点的排放分担率大;发动机怠速和高速低负荷点与整车循环排放关联度最高。 相似文献
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3 台排放控制技术路线相同但额定功率不同的非道路用挖掘机实际作业工况下的排放结果和台架工况下的排放结果之间存在较大的差异性,实际作业工况的氮氧化物(NOx)排放量为台架工况的 1.5~3.5 倍。为了研究产生排放差异性的原因,以 1 台满足非道路柴油移动机械第四阶段排放法规要求的柴油机和搭载该柴油机的挖掘机为研究对象,在台架上对该柴油机进行非道路稳态循环(NRSC)和非道路瞬态循环(NRTC)试验,实际作业工况试验则主要通过便携式排放检测系统(PEMS)设备对挖掘机进行排放试验,并利用功基窗口方法对挖掘机实际作业排放进行评估。结果表明:挖掘机实际作业工况主要分布在较高转速范围内,且扭矩变化剧烈,而台架工况的转速分布均匀,扭矩变化相对较小。因此,台架试验结果
并不能准确反映机械实际排放情况。 相似文献
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S. Soylu 《International Journal of Automotive Technology》2014,15(3):369-376
Engine load-speed frequency map of a hybrid city bus, which operates on the routes of Sakarya Municipality, was compared with that of European Transient Cycle (ETC) and World Harmonized Transient Cycle (WHTC), which are the certification test cycles. It was observed that the hybrid city bus engine operates mostly at three main regions, which are idling (30% load and 750 rpm), motoring (0% load and 1200 rpm) and high load (80% load and 1800 rpm) conditions under real world urban driving conditions. However, engine load-speed frequency maps of the certification test cycles are significantly different and cannot represent the real world urban driving conditions of the hybrid city bus. Therefore, the Particle Number (PN) emissions of the hybrid city bus were investigated under real world urban driving conditions. The aims of work were to examine the effects of city bus hybridization on the particle emissions and develop PN emission factors. The PN concentrations and size distributions together with engine operating conditions were measured with a Particle Measurement Program (PMP) compliant system, which involves a condensation particle counter (CPC) and a particle sizer (EEPS). The measurements under real world urban driving conditions indicated that the emission factors of the hybrid city bus for the PN and Total PN are 8.99E+12 and 2.51E+13 #/kW-h, respectively. The PN size distribution measurements indicated that the particles up to approximately 20 nm are not very sensitive to changes in engine power and they are exist even during motoring conditions. But, the particles in the size range from 20 to 200 nm are very sensitive to sudden changes of the engine power. 相似文献
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C. L. Myung J. Kim S. Kwon K. Choi A. Ko S. Park 《International Journal of Automotive Technology》2011,12(3):331-337
This study was conducted for the experimental comparison of particulate emission characteristics between the European and
World-Harmonized test cycles for a heavy-duty diesel engine as part of the UN/ECE PMP ILCE of the Korea Particulate Measurement
Program. To verify the particulate mass and particle number concentrations from various operating modes, ETC/ESC and WHTC/WHSC,
were evaluated. Both will be enacted in Euro VI emission legislation. The real-time particle emissions from a Mercedes OM501
heavy-duty golden engine with a catalyst based uncoated golden DPF were measured with CPC and DMS during daily test protocol.
Real-time particle formation of the transient cycles ETC and WHTC were strongly correlated with engine operating conditions
and after-treatment device temperature. The higher particle number concentration during the ESC #7 to #10 mode was ascribed
to passive DPF regeneration and the thermal release of low volatile particles at high exhaust temperature conditions. The
detailed average particle number concentration equipped for golden DPF reached approximately 4.783E+11 #/kWh (weighted WHTC),
6.087E+10 #/kWh (WHSC), 4.596E+10 #/kWh (ETC), and 3.389E+12 #/kWh (ESC). Particle masses ranged from 0.0011 g/kWh (WHSC)
to 0.0031 g/kWh (ESC). The particle number concentration and mass reduction of DPF reached about 99%, except for an ESC with
a reduction of 95%. 相似文献
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用于混合动力控制的汽油机动态转矩建模仿真 总被引:1,自引:0,他引:1
针对混合动力系统能量管理及动力平稳传递控制策略开发的需要,以MATLAB/SIMULINK仿真软件为工具,建立了发动机平均值模型,模型能够根据发动机转速和节气门开度实时计算出发动机的稳态和动态转矩。在发动机动态试验台上验证了该模型,表明模型达到了需要的计算精度和实时性要求。对给定的转矩曲线进行动态跟随时发动机的节气门开度变化情况进行了仿真分析。模型可用于混合动力控制策略开发中的仿真及在线转矩估计,为并联式混合动力系统能量分配和动态协调控制中的发动机转矩反馈提供了基础。 相似文献
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Recently, the demands for improved fuel economy have been continually rising because of environmental protection policies,
legislative pressures on emissions and increases in the price of oil. Reducing the friction power loss in a production engine
may be regarded as one of the most effective technologies for improving fuel economy because the technology is cost effective
and applicable to a great number of vehicles. This paper describes attempts to measure the torque needed to drive a camshaft
and to examine the sources of the torque fluctuations in order to analyze the friction in valvetrains. The measurements were
performed through a cam sprocket-type torquemeter, which was able to measure the torque of the valvetrain under actual engine
operating conditions. In the cam torque measured, the fluctuations were mainly dependent on the primary oscillations caused
by cam events and the secondary oscillations caused by the valvetrain natural frequency. The range of the fluctuations became
greater at high speed because of the inertial mass. The resulting FMEP (friction mean effective pressure) of the valvetrain
decreased, and the effective peak tension increased with an increase in the engine speed. 相似文献
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为评价总线电压对电机转矩以及效率的影响,在动态测功机试验台架上设计相应的试验,测量总线电压在400~455 V之间变化时某三相异步感应电机的输出转矩和效率。结果表明,在电机低效率区域,电机效率受总线电压影响较大。电机输出转矩相对于目标转矩有平均0.5 s的延时,在高总线电压、高电机转速区域,电机控制器启动自保护功能,输出转矩远小于目标转矩。中国城市公交典型工况测试表明,对经济性影响最大的前80%的电机工况点主要分布于受总线电压变化影响较小的高效率区,在城市公交工况下对电机效率的粗略分析可以忽略总线电压的变化。 相似文献
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为解决小功率柴油发电机组在高海拔环境使用过程中功率不足及冒黑烟问题,设计了一种小功率柴油发电机组电动增压装置。该装置由压气机和低压直流高速电机构成,电机可无级调速,由发动机充电机14V电源供电,设计在高海拔环境和额定工况下工作。为此,在试验的基础上进行理论设计,确定了增压装置主要参数以及增压装置主要尺寸等,为电动增压器选型提供依据。该装置可提高小功率柴油机的输出功率和扭矩,降低排放烟度,进而提高发电机组的输出功率,增强发电机组的高海拔适应性,降低发电机组的排放烟度。 相似文献
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基于发动机外特性和万有特性模型、汽车动力性模型以及汽车燃油经济性模型,使用Matlab语言设计汽车动力性、燃油经济性、模拟计算程序,并进行实车模拟计算,所得结果与实际相吻合。 相似文献