Particle size distribution from a GTL engine.

Measurements of exhaust particle number concentration and size distribution from an engine fueled with GTL at different engine loads and speeds were carried out by using a two-stage dilution system. The results for GTL were compared with those from the original engine fueled with diesel. The fuel composition and engine operation condition had significant effects on the exhaust particle size distribution, the total exhaust particle number and volume concentrations. For both fuels, the load had no significant influence on the total exhaust particle number concentration at middle speed, while the total exhaust particle number concentration increased with the increase of the load at high speed. At 1400 rpm and 2200 rpm, the total exhaust particle volume concentration increased as the load increased for both fuels. GTL was found to be a "cleaner" fuel. Compared with diesel, under the same operation conditions, the total exhaust particle number concentrations decreased 18-92%, and the total exhaust particle volume concentrations for GTL decreased 21-59%.