INVESTIGATION OF THE POTENTIAL FOR IMPROVING THE EFFICIENCY OF A SPARK-IGNITION ENGINE OPERATING ON NATURAL GAS FUEL

Since natural gas (mostly methane) is readily available and enjoys a favorable cost advantage through lower taxes and some price regulations, the popularity of conversion of gasoline engines to natural gas has increased significantly in recent years. However, fuel cost rather than energy efficiency has been the primary motivation behind these engine conversions, and little emphasis has been placed on the anti-knock, wide flammability, and emissions characteristics of methane. A data base was established in Phase I utilizing a wedge-shaped combustion chamber to show effects of equivalence ratio, ignition timing, and compression ratio for engine operation on natural gas whose primary component was methane. Baseline performance data were obtained for engine operation on research grade indolene and natural gas. The reoptimization process for the engine operating on natural gas fuel included determining minimum best torque spark timing as a function of equivalence ratio from 120% of the stoichiometric fuel rate to the lean limit fuel rate for a range of compression ratios from 8.4:1 to 18.5:1. The optimum compression ratio for the wedge-shaped combustion chamber was selected based on data for both part throttle and wide-open throttle operation. In Phase II, a hemispherical combustion chamber was used to show the effects of changing combustion chamber configuration on the pertinent engine operating parameters.

• Corporate Authors:

  Southwest Research Institute

  6220 Culebra Road, P.O. Drawer 28510
  San Antonio, TX  United States  78228-0510
• Publication Date: 1985-10

Media Info

• Pagination: 117 p.

Subject/Index Terms

• TRT Terms: Combustion chambers; Compression; Databases; Economic efficiency; Improvements; Methane; Natural gas; Shape; Spark ignition engines
• Uncontrolled Terms: Conversion; Efficiency; Ignition timing
• Old TRIS Terms: Compression ratio
• Subject Areas: Economics; Geotechnology; Highways; Materials; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00453544
• Record Type: Publication
• Source Agency: Energy Research Abstracts
• Report/Paper Numbers: DOE/CE/50072-1
• Contract Numbers: AC01-84CE50072
• Files: TRIS
• Created Date: Aug 27 2004 9:26PM