Search Results

The exhaust emissions from a gasoline direct injection (GDI) engine were sampled using the bottle in bag method and analysed using gas chromatography/mass spectrometry (GC/MS). The GDI engine was run two times using two specially mixed fuels: a typical European base fuel containing additive and a fuel representing worst-case of European gasolines, which is a standardized European fuel, CEC RF 86-A-96, prone to form deposits. The engine was run 60 h for each fuel simulating city driving. Emissions were taken at times 0 h (at the start of the engine), 30 h and 60 h. As a complement, particulate emissions derived from the additized base fuel were sampled on a glass filter during the first 30 h engine run. The extractable organics contained in the filter were analysed using GC/MS analysis. Generally, the emissions were dominated by gasoline components with similar relations as in the gasoline.

This work investigates the influence of fuel parameters on deposit formation and emissions in a four-cylinder direct injection stratified charge (DISC) SI engine. The engine tested is a commercial DISC engine with a wall-guided combustion system. The combustion chamber deposits (CCDs) were analyzed with gas chromatography / mass spectrometry as well as thickness and mass measurements. Intake valve deposits (IVDs) were analyzed for mass, while internal injector deposits were evaluated using spray photography. The CCD build-up was obtained with the CEC1 F-020-A-98 performance test for evaluation of the influence of fuels and additives on IVDs and CCDs in port fuel injected SI engines. The 60 h test is designed to simulate city driving. Four fuels were compared in the study: a base gasoline, with and without a fuel additive, a specially blended high volatility gasoline, and a fuel representing the worst case of European gasolines; neither of the latter two had additives.

Combustion products, exhaust emissions and engine exhaust deposits formed on thermocouples, positioned after the heat exchanger of an engine power plant, were analyzed chemically. The engine was a lean burn 18W28SG 50 Hz (Wärtsilä NSD, Trollhättan Sweden) fuelled with natural gas equipped with a catalyst (Süd-Chemie NMHC catalyst). The exhaust emissions were sampled using the off-line bottle-in-bag (BiB) method and were analyzed by gas chromatography/flame ionization (GC/FID). Heavier organic compounds and aldehydes were separately collected using adsorption cartridges. The combustion products measured in the emissions were mainly ethene, propene and formaldehyde indicating normal combustion of the fuel in the engine. Organics contained in the engine exhaust deposits were extracted using three different extraction methods: thermal desorption (TD), liquid extraction (LE) and super critical fluid extraction (SFE). The extracts were analyzed by GC/MS.