Particulate Matter Emissions and the Role of Catalytic Converter During Cold Start of GDI Engine

This work aimed to study nano-scale particulate matter originating from gasoline direct injection engine during cold start and warm up operating conditions and to identify the role of the three-way catalytic converter on nano-scale particulate during cold-start and warm-up operating conditions. This work used a 4-stroke, 1.6 litre, wall guided gasoline direct injected, turbocharged and intercooled SI engine equipped with a three-way catalytic converter for this investigation. It used a fast particle spectrometer for the measurement of exhaust nano-scale particles upto 1000 nm diameter. This work identified that about 98% of the particles during cold-start are in the size range below 25 nm diameter; the particle count during cold-start measured upstream of the catalytic converter is three orders of magnitude higher than the downstream measurement; the difference observed for the particles in the size range 5-25 nanometer diameter seems to follow the trend of the conversion characteristics of CO in the catalytic converter during the warm-up period at low load and low speed engine operating conditions.