Arctic Biodiesel Performance and PM Number Emissions

抄録

The use of renewable fuels such as biodiesel continues to increase to assist in meeting greenhouse gas emissions targets. These biodiesels must operate in all environments, as is expected of standard Diesel fuel, such as the prolonged periods of cold experienced in Scandinavia. There are a number of biodiesel fuels and additives available to ensure adequate operation in these cold conditions. With the Euro 6 legislation already in place attention is turning to its replacement with an understanding that the testing cycles and the targets will change. Particular attention is being paid to NOx and PM as the levels of these emissions experienced in lab vehicle tests has not translated to real world reduction. Concern about the particulate size and number, not just total mass emitted is likely to be reflected in any new legislation. There is evidence that biodiesel use results in higher PM number emissions and higher ultrafine emissions. This study presents the results examining the performance and emissions of an arctic biodiesel. The engine is a CI, 6 cylinder, 3.2 liter with variable geometry turbo, common rail injection utilizing an operator controllable ECU allowing full control over injection timing, injection pressure and the turbo geometry. The engine makes no use of any manufacture provided maps. All emissions control (EGR, filters) have been removed from engine to investigate fuel impacts alone. Tests have been conducted at three engine speeds at up to 4 loads and 5 injection timings advancing before TDC. Particular attention has been paid to the PM size distribution emitted using a Cambustion DMS500 spectrometer along with specific NOx. Engine thermal efficiency, specific fuel consumption , in-cylinder pressure and heat release have also been collected and analyzed. Comparison has been made against a petroleum based Diesel fuel.