Time filter

Source Type

Wang S.X.,Chinese Research Institute of Highway | Wang S.X.,China Agricultural University | Zhang L.,Chinese Research Institute of Highway | Zhang L.,China Agricultural University | And 4 more authors.
Applied Mechanics and Materials | Year: 2014

In order to study the fatigue reliability of taxis, a test method that correlated typical user road with proving ground reliability road is proposed. According to the result of investigation, after taking the road test on the user road, the load spectrum of taxis on the condition of typical user road is obtained. Then the rain flow counting method is used to obtain the load distribution matrixes through analyzing the two groups of data that are tested above, and with pseudo damage as a quantitative basis for the calculation of taxis fatigue damage that generated from load spectrum, an equivalent relationship is established between the two. The calculation results indicate that the ratio of damage of the typical user road to proving ground reliability road is 1 to 148.8, if regarding 600,000 km as total scrapped mileage of a taxi, 4,000 km reliability test on proving ground can achieve the same damage. © (2014) Trans Tech Publications, Switzerland.

Liang B.,Beijing Institute of Technology | Liang B.,Beijing Automotive Research Institute Co. | Ge Y.,Beijing Institute of Technology | Tan J.,Beijing Institute of Technology | And 5 more authors.
Journal of Aerosol Science | Year: 2013

Two Euro 4 gasoline passenger vehicles (one gasoline direct injected vehicle and one port fuel injected vehicle) were tested over the cold start New European Driving Cycle (NEDC). Each vehicle was respectively fueled with gasoline and M15 methanol gasoline. Particle number concentrations were measured by the electrical low pressure impactor (ELPI). Particle masses were measured by gravimetric method and estimated from the number distributions using two density distributions (one is constant with the particle size and one is power law related with the size). The first 7 stages of ELPI were used for estimation. The results show that for each vehicle, PM masses measured by gravimetric method, the total PM numbers measured by ELPI and estimated PM masses for M15 are lower than those for gasoline. For each kind of fuel, PM masses by two methods and total PM numbers from the GDI vehicle are higher than those from the PFI one. PM number distribution curves of the four vehicle/fuel combinations are similar. All decline gradually and the maximum number of each curve occurs in the first stage. More than 99.9% numbers locate in the first 8 stages of which diameters are less than 1 μm. PM number emissions correlate well with the acceleration of the two vehicles. The estimated particle masses were much lower than the gravimetric measurements. © 2012 Elsevier Ltd.

Wang A.,Beijing Institute of Technology | Ge Y.,Beijing Institute of Technology | Tan J.,Beijing Institute of Technology | Fu M.,Beijing Institute of Technology | And 7 more authors.
Journal of Environmental Sciences | Year: 2011

On-road emission and fuel consumption (FC) levels for Euro III and IV buses fueled on diesel and compressed natural gas (CNG) were compared, and emission and FC characteristics of buses were analyzed based on approximately 28,700 groups of instantaneous data obtained in Beijing using a portable emissions measurement system (PEMS). The experimental results revealed that NOx and PM emissions from CNG buses were decreased by 72.0% and 82.3% respectively, compared with Euro IV diesel buses. Similarly, these emissions were reduced by 75.2% and 96.3% respectively, compared with Euro III diesel buses. In addition, CO2, CO, HC, NOX, PM emissions and FC of Euro IV diesel buses were reduced by 26.4%, 75.2%, 73.6%, 11.4%, 79.1%, and 26.0%, respectively, relative to Euro III diesel buses. The CO2, CO, HC, NOx, PM emissions and FC factors all decreased with bus speed increased, while increased as bus acceleration increased. At the same time, the emission/FC rates as well as the emission/FC factors exhibited a strong positive correlation with the vehicle specific power (VSP). They all were the lowest when VSP < 0, and then rapidly increased as VSP increased. Furthermore, both the emission/FC rates and emission/FC factors were the highest at accelerations, higher at cruise speeds, and the lowest at decelerations for non-idling buses. These results can provide a base reference to further estimate bus emission and FC inventories in Beijing. © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.

Liang B.,Beijing Institute of Technology | Liang B.,Beijing Automotive Research Institute Co. | Ge Y.,Beijing Institute of Technology | Tan J.,Beijing Institute of Technology | And 5 more authors.
Qiche Gongcheng/Automotive Engineering | Year: 2014

A comparative study on unregulated emissions from a direct injection gasoline vehicle fueled with gasoline and M15 methanol-gasoline is conducted. Test cycles include a regulated cycle and three unregulated cycles simulating traffic conditions in Beijing. The results show that for each fuel, emissions of total aldehydes and ketones, major aldehydes and ketones and total BTEX (Benzene, Toluene, Ethylbenzene and Xylenes) over regulated cycle at hot start mode are lower than those at cold start mode. For each test cycle, formaldehyde emission with M15 is higher than that with gasoline. Emissions of total aldehydes and ketones, major aldehydes and ketones, formaldehyde and total BTEX with high speed cycle are the lowest among the four cycles at hot start mode.

Fu M.,Beijing Institute of Technology | Ding Y.,Vehicle Emission Control Center | Ge Y.,Beijing Institute of Technology | Yu L.,Beijing Institute of Technology | And 4 more authors.
Atmospheric Environment | Year: 2013

Ship emissions are widely recognized as a relevant source of the total air pollution and have a remarkable impact on air quality of the sea, territorial waters and coastal areas. To assess this impact, various emission models have been developed to calculate the emission inventory of ship based on ship activity data. However, few studies in China have collected the emission factors of local ship which are decisive factors in accurate assessment of ship emission inventory. This study intends to obtain emission data of inland ships on the Grand Canal of China by conducting on-board emission tests. We measured CO, HC NOx and PM emission from 7 inland ships of different engine powers, and derive distance-based and fuel-based emission factors on the basis of the cruise and manoeuvring (including port departure and port arrival) operating modes. The results show that average distance-based emission factors of CO, HC and PM for manoeuvring mode are higher than those for cruise mode. For NOx, average distance-based emission factors for cruise mode are higher than those for port arrival mode but lower than those for port departure mode. Particular number (PN) distribution analysis indicates that larger amounts of small size PM (Dp<0.01μm) appeared on manoeuvring mode, which can affect regional air quality and human health. The average fuel-based emission factor of NOx in this study is 1.4-4.3 times higher than those in on-board studies. When compared with estimated Tier 1 standard limit (in unit of gkg-1 fuel), NOx in this study is nearly twice of Tier 1. The higher NOx emission indicates that stricter emission strategies and policies should be implemented to control ship emission in China. It is noticeable that distance-based emission factors of four pollutants are higher with the increase of engine loads. © 2013.

Discover hidden collaborations