Numerical investigation on combustion characteristics and emissions of methane/biogas blends in in a swirling flow gas turbine combustor

Utilizing biogas in gas turbines for power generation offers a promising strategy for mitigating pollutants from combustion and reducing our dependence on nonrenewable fuels. The paper presents a numerical simulation of the combustion of methane and biogas mixtures in a single standard Siemens SGT-۱۰۰ dry low emission (DLE) combustor under actual engine operating conditions. The investigations were conducted using five different fuels: pure methane (۱۰۰% ), ۱۰% biogase (۹۰% + ۱۰% ), ۲۰% biogase (۸۰%+ ۲۰% ), ۳۰% biogase (۷۰% + ۳۰% ), ۴۰% biogase (۶۰% + ۴۰% ) with a constant equivalence ratio value ( = ۰.۷). A numerical approach was adopted, utilizing the K-ε turbulence model, EDC combustion model, DO radiation model, GRI۳.۰ chemical mechanism, and ۱۵,۰۰۰ computational cells. As the percentage of biogas increases, the flame temperature, which is the most significant parameter, decreases, resulting in a decrease in emissions. On the other hand, reducing the flame temperature leads to increased incomplete combustion and, consequently, higher production of emissions. The findings of the study clearly indicate the feasibility of utilizing such fuels in combustion systems.

Keywords:

Numerical simulation , Gas turbine , Methane , Biogas , Combustion , Emissions.