OPERATION AND PERFORMANCE OF A MONOFUELED COMPRESSION IGNITION, DIRECT INJECTION, NATURAL GAS HEAVY DUTY ENGINE

Document Type

Conference Proceeding

Publication Date

12-2-2024

Department

Department of Mechanical Engineering-Engineering Mechanics

Abstract

The Compression Ignition of Directly Injected Natural Gas (CIDI NG) offers a potential 25% reduction in CO2 emissions due to its high hydrogen-to-carbon ratio compared to diesel, while achieving ultra-low PM formation with high efficiencies and load capability. The primary challenge of a CIDI NG engine is achieving suitable ignition temperatures, upwards of 1150K, and in-cylinder conditions required for the stable ignition and combustion of late cycle high pressure direct injection of the fuel over a wide operating range. This experimental study investigates CIDI NG combustion in a heavy-duty Single Cylinder Research Engine (SCRE). The SCRE uses a combination of ignition-enhancing technologies targeting the required conditions, including an increased compression ratio, intake charge heating, thermal barrier coatings, EGR, and NG pilot injection. Additionally, charge mixing is promoted through the refinement of the piston bowl geometry, resulting in improved efficiency and reduced soot formation. This study shows the effect of the implemented hardware technology (CR, Bowl Geometry, Thermal Barrier Coating) on the combustion at key operating conditions (low, medium, high load, high-efficiency operation, low emissions) of the NG CIDI engine. Stable combustion and engine operation were demonstrated over a wide load from 5.5 bar to a peak load of 25 bar IMEPg, and a maximum indicated thermal efficiency (ITE) of 48.8% at a load of 15.2 bar IMEPg was achieved. The work conducted with the single cylinder research engine shows that this operation is feasible and can become commercially available in the future.

Publication Title

American Society of Mechanical Engineers, Internal Combustion Engine Division (Publication) ICE

ISBN

[9780791888520]

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