Variations in natural gas composition not only change bulk properties like heating value and adiabatic flame temperature, but also affect the reactivity of the gas during combustion in legacy compressor engines. Gas blends with high amounts of non-methane hydrocarbons are more reactive and alter combustion phasing in ways which can negatively affect engine operation and NOx emissions. These issues have and will continue to become more prevalent as natural gas production continually shifts towards shale resources.
This work investigates the impacts of changing fuel composition on engine operation...
This work investigates the impacts of changing fuel composition on engine operation and emissions, as well as on fundamental fuel properties. Several fuel sweep datasets from different legacy engines are used to help draw broad conclusions about the impact of fuel speciation depending on engine type and operating condition. Further, the relationship between this engine behavior and fundamental fuel properties is explored. The response of engine operation and emissions to changing fuel reactivity is also observed in the context of the trapped equivalence ratio control method. A correction to the method which accounts for fuel reactivity effects on NOx is proposed and assessed with available data.