Improved spark ignition engine efficiency through turbosupercharged lean operation. Final report

Technical Report · Sun Nov 01 04:00:00 EST 1981

OSTI ID:6282857

Johnson, R T

A comprehensive test program to evaluate Lean Supercharged Operation (LSO) of the spark ignition engine for improved efficiency was conducted. The evaluation involved two major experimental programs: an initial study of the power, emissions and efficiency of a single cylinder engine, followed by a series of tests using a turbocharged multicylinder engine to verify results. The relationships between engine power, efficiency, and emissions and the engine operating variables such as absolute intake manifold pressure, Exhaust Gas Recirculation rates, and spark timing were studied. Results from both phases of the experimental program indicated that LSO can provide significant improvements in engine efficiency for NO/sub x/ emissions comparable to, or lower than, the naturally aspirated engine. For equal power output from the single cylinder engine, efficiency increases of 2.25 points (14%) were accompanied by reductions in Brake Specific NO/sub x/ (BSNO/sub x/) emissions of approximately 76%. For a case at equal BSNO/sub x/ emissions, an efficiency improvement of 6.4 points or over 40% was observed. Although not as dramatic, similar improvements were obtained from the turbocharged multicylinder engine. In both cases, the improvements were significant only at higher values of absolute intake manifold pressure. A smaller displacement engine operating at higher mean effective pressures will be needed to utilize the benefits of Lean Supercharged Operation.

• Research Organization: Missouri Univ., Rolla (USA). Dept. of Mechanical Engineering
• DOE Contract Number: FG19-78ET12236
• OSTI ID: 6282857
• Report Number(s): DOE/ET/12236-1; ON: DE85003671
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330101* -- Internal Combustion Engines-- Spark-Ignition
CHALCOGENIDES
COMPRESSORS
EFFICIENCY
ENGINES
EXHAUST GASES
FLUIDS
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
NITROGEN COMPOUNDS
NITROGEN OXIDES
OPERATION
OXIDES
OXYGEN COMPOUNDS
SPARK IGNITION ENGINES
SUPERCHARGERS
TESTING
WASTES