Numerical investigation of the internal flue gas recirculation system applied to methane powered gas microturbine combustor

Abstract

The gas microturbines gain significance in various industry sectors. One of their most crucial advantages is the capability of utilizing variety of fuels. At the same time, the emissions regulations become increasingly strict. This is why there is a need to look for a new technological solution to limit the emissions of selected substances, like carbon monoxide (CO) and nitrogen oxides (NOx). The internal recirculation of the flue gases is well known to limit the temperature peak and for the homogenization of the temperature field gradient in different combustion chambers. This paper presents a numerical investigation of a novel internal flue gas recirculation system applied to gas microturbine combustors. The ability to perform an internal exhaust gases recirculation by adding a combustor internal pipe system was verified numerically. This paper exposed the numerical investigation methods and obtained results. The study presents the concept and results performed on three cases of internal exhaust gases recirculation systems applied to a reference combustor. The work permitted to demonstrate numerically that it is possible to perform an autonomous exhaust gases recirculation inside gas microturbine combustor at a maximum global rate of 0.51%, and that the recirculation system has an impact on the combustion processes without specially modifying the combustor work parameters.

Computational Fluid Dynamics (CFD) Assessment of the Internal Flue Gases Recirculation (IFGR) Applied to Gas Microturbine in the Context of More Hydrogen-Enriched Fuel Use

“…Each of the evaluations was conducted for the hydrogen mass fraction in the reference fuel (here, methane) ranging from 0 to 0.5. This numerical investigation of the IFGR system applied to the gas microturbine is an extension of preliminary studies performed previously and described in [23,24].…”

Effects of hydrogen addition on NO<i>_x</i> formation in a non-premixed methane low-NO<i>_x</i> combustor

“…An FGR rate higher than 20% may cause unstable combustion. FGR is classified as external flue gas recirculation (EFGR) (Pan et al, 2022) and internal flue gas recirculation (IFGR) (Fąfara and Modliński, 2022), depends on whether part of flue gas is recirculated outside or inside of the furnace. Due to the inconvenient transformation, IFGR has not received sufficient focus in contrast to EFGR.…”

Improving the Efficiency of Fuel Combustion with the Use of Various Designs of Embrasures

“…Since the first computational experiment, a wide range of applications has appeared for modeling the flow of liquids and gases, interfacial interactions, flows with chemical reactions, and heat transfer using CFD. These include: Ansys (Fluid/CFX) [22][23][24], Star CCM+ [25,26], SigmaFlame [27,28], CEDRE [29,30], and Fire 3D [31].…”