Implementable Changes to a Large-Bore Single Cylinder Natural Gas Engine for Improved Emissions Performance

Abstract

In the midst of a controversial time in the energy industry, it is hard to deny the fact that petroleum-based combustion will be a mainstay for many years to come. In light of this reality, it is the task of the engineering community to make natural gas combustion as safe, efficient, and environmentally conscious as possible. This study considers the implementable changes of variable spark timing and reduced cooling fan loads on a natural gas reciprocating-piston internal combustion engine. Emissions are observed over a range of engine speed, engine load, and spark timing conditions.

While active engine controls reduce fuel consumption and emissions, many natural gas pipeline engines in service today operate at set conditions. Each engine can then only be designed to have a small range of optimum performance for a given configuration. While installing controls is possible, it is an expensive endeavor, creating interest in optimizing an engine to its specific operating conditions. This investigation explores emissions and other engine performance data over three engine speeds, three engine loads, and five spark timing configurations on an Ajax E-565 natural gas engine.

In addition to the spark timing study, an investigation into the cooling system is performed to see if and when the engine is exerting wasted energy into cooling itself. The study shows that the engine is in fact supplying too much energy to its fan for moderate climates, warranting further investigation into ways to reduce this parasitic loss.