When methanol was used as fuel, hazardous unburned methanol, aldehyde were exhausted. To solve this, low heat rejection engine with ATAC (Active Thermo-Atmosphere Combustion) system was investigated. The characteristics of combustion process and emissions from ceramics methanol fueled ATAC engine were examined. Widening of ATAC operation region at low BMEP operation condition by use of methanol, and reduction of carbon monoxide emission was persuaded by experiment. By using ceramics for the combustion chamber, the surface temperature of combustion chamber wall was kept at high temperature by 100 to 250 degree C. When the temperature of combustion chamber wall became high, the thermal efficiency was reduced because to too early ignition timing in ATAC operation. Supplying a fuel lean mixture to the engine had a good result in both exhaust emissions and fuel consumption. The relationship between the surface temperature and both formaldehyde emission and instantaneous heat transfer was investigated. The instantaneous heat flux and/or the temperature swing increased with the increment of the time-averaged temperature. Sudden rise of the instantaneous heat flux was observed when the surface temperature was higher than about 700 K. It was expected that the frame quenching layer was destroyed. As a result, at the high surface temperature formaldehyde emission generated in the quenching layer decreased.
Combustion and emissions of low heat rejection ceramics methanol ATAC engine - surface temperature effect on aldehyde emission and heat transfer
Verbrennung und Abgase des Keramik/Methanol-ATAC-Motors mit geringen Wärmeverlusten. Auswirkung der Oberflächentemperatur auf die Aldehydemission und den Wärmeübergang
1994
8 Seiten, 22 Bilder, 6 Quellen
Conference paper
English
Combustion and emissions of low heat rejection ceramic methanol ATAC engines
Tema Archive | 1996
|Automotive engineering | 1994
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