טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentFleischman Rafael
SubjectNanoparticle emissions and performance of a bus retrofitted
with Diesel Particle Filter
DepartmentDepartment of Mechanical Engineering
Supervisor Dr. Leonid Tartakovsky
Full Thesis textFull thesis text - English Version


Abstract

Abatement of particle emissions by road transport is considered one of the main challenges in the quest for better air quality. Studies released in the last decades have indicated that particles produced by diesel engines represent serious urban air pollution problem and cause adverse health effects.

Because of the long service life of heavy-duty diesels (approximately 15 years for buses), there is a large number of older-technology vehicles on the road. Cleaning up exhaust gases from these older vehicles presents an opportunity to improve air quality. Thus, retrofitting older buses with diesel particulate filter (DPF) is a cost-effective measure to quickly and efficiently reduce particulate matter emissions.

This study experimentally analyses the impact of DPF retrofitting on particulate emissions and engine performance aspects of in-use diesel buses. For the purpose of this research, 18 in-use interurban and urban diesel buses of Euro III technology generation were retrofitted with DPFs from three different manufacturers.

The influence of DPF on engine emission particle number concentrations and size distribution were measured and evaluated at various engine operating modes. Engine-out and tailpipe particle emissions were measured three times during a period of 12 months of buses operation after DPF retrofit installation. Moreover, buses fuel economy, backpressure build-up, lubricating oil quality, as well as maintenance and drivability aspects were investigated.

DPF retrofitting was found to cause an increase of 1.8% to 0.6% in fuel consumption, depending on the bus type. However, it also reduces in average by 96% the total number based particle emissions. Mass based particle emission reductions are found to be 96% as well.