Numerical Analysis and Optimization of Syngas Flow Rates for Gas Turbine for Low Heating Value Fuel

Abstract An engineering thermodynamic model has been developed to study the phenomena that large discrepancies found among the different temperature sensors monitoring the exhaust of the gas turbine designed for syngas. The mathematical model utilized large amounts of industrial operation data at different typical power loads for validation and good agreements were found between the measured and calculated exhaust temperature using input boundary conditions not in the training sets. The reason for the large temperature discrepancies of exhaust corresponding to different combustion chambers has been attributed to the deviation between the flow rates of the compressed air from single compressor to different combustion chambers through analysis with the mathematic model. Finally, a method to reduce the temperature discrepancies has been proposed with the mathematic model using industrial operation data from various power loads. The proposed method can quickly calculate the required syngas flow rates to different combustion chambers based on measured differences of exhaust temperatures. The scheme of varying syngas flow rates to different combustion chambers according to the proposed method has been verified by simulation. The impacts to the stability of combustion and NOx emission by the scheme of varying syngas flow rates to different combustion chambers according to the proposed method have also been studied via computational fluid dynamics (CFD) simulations and found that there is little impact on the stability of combustion and it may lead to slightly lower NOx emission for all power loads.