Effect of Water Injection into Aero-derivative Gas Turbine Combustors on NOx Reduction

Oxides of Nitrogen (NOx) generated from gas turbines causes enormous harm to human health and the environment. As a result, different methods have been employed to reduce NOx produced from gas turbine combustion process. One of such technique is the injection of water or steam into the combustion chamber to reduce the flame temperature. A twin shaft aero-derivative gas turbine was modelled and simulated using GASTURB simulation software. The engine was modelled after the GE LM2500 class of gas turbine engines. Water injection into the gas turbine combustor was simulated by implanting water-to-fuel ratios of 0 to 0.8, in an increasing order of 0.2. The results show that when water-to-fuel ratio was increased, the Nox severity index reduced. While heat rate and fuel flow increased with water-to-fuel ratio (injection flow rate).