The difference between real driving emissions of heavyduty vehicle and the approval emission results of engine bench test was caused mainly by the discrepancy of both test conditions. Taking a LNGelectricity hybrid bus in Guangzhou as the research object, the operation data such as vehicle speed, engine speed and torque were collected in real time by PEMS and CANbus when the bus ran along a typical bus line. The distribution characteristics of actual working conditions for the bus engine were analyzed statistically and compared with those of ETC and WHTC conditions. Due to the power control strategy, speed limit, bus running rules and so on, actual operating conditions of this hybridbus engine were mainly in the low and middle speed region with a long duration at the small and medium torque, which was different from the distribution of medium and high speed and torque for ETC set conditions. In addition, the distribution was also different from that of medium speed and medium and small torque for WHTC set conditions. Compared with ETC, the characteristic parameters such as average engine speed, average power and idling ratio for WHTC were more close to those of actual operating conditions in Guangzhou.
PENG Meichun
,
ZENG Longlong
,
ZHANG Weilun
. Analysis of Real Driving Conditions for LNG-Electricity Hybrid Bus Engine[J]. Vehicle Engine, 2017
, 0(6)
: 36
-42
.
DOI: 10.3969/j.issn.1001-2222.2017.06.007
