Pollutant emissions analysis of a hybrid drive bus in a SORT 2 test

Abstract

The paper presents the results of emission tests of a city bus equipped with a series hybrid drive. The measurements were performed in accordance with the current guidelines of the standardized SORT 2 test (Standardized On-Road Test Cycles 2) reflecting the typical urban driving conditions. The analysis includes gaseous compounds (CO2, CO, THC and NOx). SEMTECH DS mobile device categorized as portable emissions measurement systems was used in the research. The test vehicle operating conditions were evaluated in relation to the operating parameters variability and the drive system. In addition, a comparison of the fuel consumption and travel velocity recorded during the test cycle have been shown. The research object was an 18-meter long city bus with a 6.7 dm3 displacement engine, meeting the current emission standards. The article discusses the issue related to the type approval of buses, which belong to the heavy vehicles group, but they are characterized by very specific operating conditions. Based on the obtained data, the ecological indicators of the tested vehicle were determined and compared with the limits in force in the current Euro VI standard.