Advanced Natural Gas Fueled Engine Development. Part 1: Design and Analyses. Final Report April 1985-July 1986

摘要

The objective of the research program was to design an advanced natural gas engine (NG 1990) to be produced in the 1990's which will have high termal efficiency and 40,000 hours durability of the valve train components before major engine overhaul. Preliminary design and feasibility of the NG 1990 advanced natural gas engine was completed. A natural gas engine simulation model predicts up to 43.6% brake thermal efficiency (5840 Btu/hp-hr BSFC) for the advanced engine with the advanced concepts like K-Miller cycle (early intake valve closing), lean burn combustion - A/F ratio = 24.5, high compression ratio up to 14:1, higher turbocharger efficiency of 63.2% overall, and axially stratified charge combustion system resulting in fast burning. The use of K-Miller cycle reduces the in-cylinder gas temperatures and allows engine operation at 14:1 compression ratio without knock tendencies. The design and analyses of the NG 1990 engine and its components like K-Miller system have been completed in the program.