Emission and fuel consumption reduction in a two-stroke engine using delayed-charging
- L.M.P./Paris VI Univ. (France)
To reduce fuel losses during the gas-exchange-process in a two-stroke engine cylinder, a simple Delayed-Charging Device was developed to first scavenge burnt gases with fresh air and then introduce a fresh charge. This paper presents recent work done on a 50cc engine (i.e. through geometry changes of the delayed-charging circuit) to reduce torque losses and further improve fuel consumption and hydrocarbon emission reduction: a fuel trapping efficiency up to 87% (to be compared to the 74% production engine`s); a mean specific fuel consumption lower than 400 g/kW.h (a mean 200 g/kW.h reduction compared to the rich-carbureted production engine); a HC emission down to 45 g/kW.h (lower than 1.3%); a delivery ratio reduction, due to the device presence, less than 6%; a maximum torque loss of 8 % for the best delayed-charging circuit geometry. Moreover, an estimate of the delayed-charging device efficiency has been done by comparing the trapping efficiencies of delayed-charging modified engines equipped with either classical carburation or with delayed-charging-duct carburation. The further improvement potentialities have been studied through combustion-used trapped-air evaluation and through simulation of the triple-carburation due to the device-produced burnt-gas back-flow.
- OSTI ID:
- 253604
- Report Number(s):
- CONF-950942-; ISBN 1-56091-673-7; TRN: IM9630%%55
- Resource Relation:
- Conference: Small engine technology conference and exposition, Milwaukee, WI (United States), 13-15 Sep 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the 1995 small engine technology conference: Small engines and the environment. P-292; PB: 497 p.
- Country of Publication:
- United States
- Language:
- English
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