Hydrocarbon Reductions through Precombustion Chamber Design in a Natural Gas Lean-Burn Engine. Topical Report, February-October 1990

摘要

A study was conducted to evaluate the effects of various precombustion chamberdesign, operating, and control parameters on the exhaust emissions of a natural gas research engine. Analysis of the results showed that engine-out total hydrocarbons and oxides of nitrogen can be reduced, relative to conventional methods, through precombustion chamber design. More specifically, a novel staged prechamber yielded significant reductions in NOx and total hydrocarbon emissions by promoting stable ignition while operating with a high percentage of theoretical excess air. Relatively light load and fuel lean operation with the Staged Prechamber simultaneously reduced baseline NOx and hydrocarbons by 47 percent and 14 percent, respectively. Emissions reductions were realized at other loads and air/fuel ratios to lesser extents. The purpose of the report is to identify and explain positive and deleterious effects of natural gas prechamber design on exhaust emissions.