在现实条件下轻型卡车拖车运行的排放率.
Bumsik Kim1, Rohit Jaikumar1, Rodolfo Souza1
1Texas A&M Transportation Institute, College Station, TX, USA.
概括
使用轻型卡车 (LDT) 拖车增加了CO2,CO,HC和NOx排放. 现实世界的测量显示与当前的排放模型存在差异,这表明需要更新模拟以进行准确的LDT拖拉影响评估.
科学领域:
- 环境科学 环境科学
- 汽车工程 汽车工程
- 大气化学 大气化学
背景情况:
- 轻型卡车 (LDT) 经常用于拖.
- 现有的拖影响研究主要集中在重型车辆上,为LDT留下了数据缺口.
- 拖车显著增加发动机负载,可能改变排气排放.
研究的目的:
- 为了量化拉操作期间LDT的使用过程中的废气排放量.
- 为了比较现实世界的LDT拖车排放量与EPA的MOVES模型的预测.
- 确定用于LDT拖拉场景的排放建模的改进领域.
主要方法:
- 使用便携式排放测量系统 (PEMS) 来从三个常见的低温测试仪收集实时数据.
- 基于EPA的MOVES模型中定义的操作模式的特征排放率.
- 与MOVES默认值比较测量的排放率.
主要成果:
- 拖操作通常导致 CO2 , CO , HC 和 NOx 的排放量增加,与大多数运输方式的非拖操作相比.
- 在拖车时在更高的操作模式下观察到CO和HC排放的显著增加.
- 测量排放量和MOVES预测之间的差异被发现,特别是在高速和高运行模式下.
- 个别的LDT在相似的运行条件下也表现出不同的排放配置文件.
结论:
- 使用LDT的现实世界拖车导致排放量高于典型的模拟.
- 环保署的MOVES模型需要改进,以准确预测拖拉过程中的LDT排放,特别是在苛刻的条件下.
- 了解这些拖动影响对于准确的空气质量评估和LDT的监管合规至关重要.
相关概念视频
Turnover Number and Catalytic Efficiency
10.7K
The turnover number of an enzyme is the maximum number of substrate molecules it can transform per unit time. Turnover numbers for most enzymes range from 1 to 1000 molecules per second. Catalase has the known highest turnover number, capable of converting up to 2.8×106 molecules of hydrogen peroxide into water and oxygen per second. Lysozyme has the lowest known turnover number of half a molecule per second.
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion....
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion....
10.7K
Work Done in an Adiabatic Process
3.5K
Consider the adiabatic compression of an ideal gas in the cylinder of an automobile diesel engine. The gasoline vapor is injected into the cylinder of an automobile engine when the piston is in its expanded position. The temperature, pressure, and volume of the resulting gas-air mixture are 20 °C, 1.00 x 105 N/m2, and 240 cm3 , respectively. The mixture is then compressed adiabatically to a volume of 40 cm3. Note that, in the actual operation of an automobile engine, the compression is not...
3.5K
Multiple Voltage Sources
1.3K
Generally, a single battery is not enough to power some devices. In such cases, batteries can be combined in two ways: in series or in parallel.
In series, the positive terminal of one battery is connected to the negative terminal of another battery. Hence, the voltage of each battery is added to give the net voltage, which is increased because each battery boosts the electrons that enter it. The same current flows through each battery because they are connected in series.
Batteries are...
In series, the positive terminal of one battery is connected to the negative terminal of another battery. Hence, the voltage of each battery is added to give the net voltage, which is increased because each battery boosts the electrons that enter it. The same current flows through each battery because they are connected in series.
Batteries are...
1.3K
Distributed Loads
613
Distributed loads are a common type of load that engineers and scientists encounter in various practical situations. Distributed loads often refer to a type of load spread over a surface or a structure and can be modeled as continuous force per unit area.
For example, consider a bookshelf filled with books stacked vertically adjacent to each other. The weight of the books is evenly distributed over the length of the shelf. As a result, the pressure at different locations on the surface of the...
For example, consider a bookshelf filled with books stacked vertically adjacent to each other. The weight of the books is evenly distributed over the length of the shelf. As a result, the pressure at different locations on the surface of the...
613
Design of Transmission Shafts
459
The design of a transmission shaft is governed by two primary specifications: the power it transmits and its rotational speed. These parameters guide the selection of the shaft's material and cross-sectional dimensions, ensuring that the material's maximum shearing stress remains within the elastic limit while transmitting the desired power at the given speed. The system's power is intrinsically linked to the applied torque. The torque applied to the shaft can be calculated by...
459
Eccentric Loading
500
Eccentric loading is a crucial concept in the study of structural engineering and mechanics, particularly when analyzing the stability and stress distribution in columns. Unlike centric loading, where the force is applied along the centroidal axis, causing uniform compression, eccentric loading occurs when a force is applied off-center. This off-center application introduces not only direct compressive stress but also bending stress, significantly influencing the column's behavior under...
500


