A problem in large-bore, slow-speed, natural gas two-stoke cycle engines is poor incylinder mixing processes caused by ineffective fuel delivery. Engines in this class are used primarily for power generation and gas compression on natural gas pipelines. Poor in-cylinder mixing can cause elevated oxides of nitrogen emissions due to thermal stratification, high carbon monoxide and unburned hydrocarbon emissions due to partial combustion, and low engine efficiency.
To address the mixing problem, a visualization technique is needed to image the fuel in the cylinder, or combustion chamber. Fuel visualization in the combustion chamber enables the advancement of current understanding of fuel injection and mixing in combustion chambers. A well-suited technique for this is Planar Laser Induced Fluorescence (PLIF). PLIF allows the user to visualize injected fuel flow and the ensuing fuel and air mixing process. A seeded gas (acetone tracer) is used such that, when irradiated with laser light, it fluoresces, enabling the gas mixture to be visible for highspeed photography within an optically accessible combustion chamber.
SOURCE: PCO-TECH Inc.