Heavy Duty Fuel Economy Program. Phase II. Evaluation of Emission Control Technology Approaches.

摘要

This report describes the laboratory effort toward reducing emission and fuel consumption in a heavy-duty gasoline engine,while retaining current durability performance. The goals were HC plus NOx of 6.7 g/kW-hr (5g/bhp-hr) CO of 33.5 g/kW-hr (25 g/bhp-hr), a ten percent reduction in specific fuel consumption and 1500hours of service accumulation,using the procedures proposed for the 1979model year. The initial laboratory evaluations involved standard carburetors, a Dresserator inductor, a Bendix electronic fuel injection system,exhaust manifold thermal reactors,exhaust gas recirculation along with a number of other engine emissions control components and operating parameters. Based on the project goals and the initial results, a system was selected to undergo final optimization and service accumulation. The system selected consisted of electronic fuel injection,thermal reactors with air injection,exhaust gas recirculation and a high energy ignition system with vacuum advance. This system met the emissions and specific fuel consumption goals and completed 1500hours of service accumulation. During the last 750hours of service accumulation, a heavy-duty oxidation catalyst was included in the exhaust system as an add-on to the optimized system. Subsequent to the 1500hours of service accumulation,this engine was installed into a heavy-duty truck for an evaluation of driveability and performance.