Fuel and Combustion

Fuel and Combustion

Numerical simulation of industrial gas turbine combustion chamber using FGM method

Document Type : Original Article

Authors
1 Faculty of Aerospace Engineering, University of Tehran, Tehran, Iran
2 Department of Aerospace Engineering, University of Tehran
3 Persian Gulf Turbine Company, Tehran, Iran
Abstract
In this paper, a numerical simulation of an industrial gas turbine combustor has been performed using two combustion models, FGM (Flamelet Generated Manifold) and EBU (Eddy Break-Up) along with a k-ε turbulence model. The main objective is to investigate the effect of the combustion model selection on the average stagnation temperature and the outlet temperature profile of the combustor, which are important from the perspective of performance and turbine component life. The simulations have been performed using Simcenter STAR-CCM+ software and a 3D meshing including fluid and solid domains. The numerical results have been compared with the reference data of the turbine manufacturer. Also, the effect of two turbulence sub-models, k-ε Realizable and k-ε Standard, on the simulation accuracy has been investigated. The findings show that the FGM model predicts the outlet temperature cooler and closer to the reference distribution with less error than the EBU. Also, the combination of the Standard k-ε turbulence model with the FGM combustion model provides a better match with the reference data.

Highlights

In this study, numerical simulation of the combustion chamber of an industrial gas turbine was performed with two combustion models, FGM and EBU, and the k-ε turbulence model. The results showed that the FGM model is more accurate in predicting the average outlet stagnation temperature than the EBU. Also, the outlet temperature profile obtained from the FGM model is closer to the reference distribution and provides a cooler temperature.

In examining the effect of the turbulence model, it was found that the k-ε Standard model has a better ability to simulate eddies, mixing of cold and hot flows, and a more uniform temperature distribution than the k-ε Realizable model. The average outlet stagnation temperature in the k-ε Standard model was calculated to be 1557.2 Kelvin (1% error) and in the k-ε Realizable model to be 1656.2 Kelvin (5.26% error), indicating the superiority of the k-ε Standard model.

Examination of the outlet chemical species showed that the most produced pollutant was NO, which is due to the high temperature of the combustion chamber. Also, the temperature distribution on the liner wall showed that the flame concentration occurs near the wall and before the first row of holes in the first zone of the chamber, which can reduce the liner life. Finally, it is suggested that by modifying the swirler and improving the DLE process, the flame will move away from the wall and the NO production rate will be reduced.

In summary, the combination of the k-ε Standard turbulence model with the FGM combustion model is considered a suitable option for accurate simulation of industrial gas turbine combustion chambers.

Keywords
Subjects

[1] J. A. Van Oijen, F. A. Lammers, and L. P. H. De Goey, "Modeling of complex premixed burner systems by using flamelet-generated manifolds," Combustion and Flame, vol. 127, no. 3, pp. 2124-2134, 2001.
[2] J. A. Van Oijen, A. Donini, R. J. M. Bastiaans, J. H. M. ten Thije Boonkkamp, and L. P. H. De Goey, "State-of-the-art in premixed combustion modeling using flamelet generated manifolds," Progress in Energy and Combustion Science, vol. 57, pp. 30-74, 2016.
[3] J. A. M. De Swart, R. J. M. Bastiaans, J. A. Van Oijen, L. P. H. De Goey, and R. S. Cant, "Inclusion of preferential diffusion in simulations of premixed combustion of hydrogen/methane mixtures with flamelet generated manifolds," Flow, Turbulence and Combustion, vol. 85, no. 3, pp. 473-511, 2010.
[4] R. L. G. M. Eggels and C. T. Brown, "Comparison of numerical and experimental results of a premixed DLE gas turbine combustor," in Turbo Expo: Power for Land, Sea, and Air, vol. 78514, p. V002T02A032, 2001.
[5] T. Cardoso de Souza, R. J. M. Bastiaans, B. J. Geurts, and L. P. H. De Goey, "LES and RANS of premixed combustion in a gas-turbine like combustor using the flamelet generated manifold approach," in Turbo Expo: Power for Land, Sea, and Air, vol. 54624, pp. 1119-1127, 2011.
[6] H. Mongia, "Gas turbine combustor liner wall temperature calculation methodology," in 37th Joint Propulsion Conference and Exhibit, p. 3267, 2001.
[7] F. L. G. Dias, M. A. R. do Nascimento, and L. de O. Rodrigues, "Reference area investigation in a gas turbine combustion chamber using CFD," Journal of Mechanical Engineering and Automation, vol. 4, no. 2, pp. 73-82, 2014.
[8] N. Rasooli, S. Besharat Shafiei, and H. Khaledi, "Combination of 1D code and CFD for performance analysis of a silo type gas turbine combustor," in Turbo Expo: Power for Land, Sea, and Air, vol. 43970, pp. 1015-1023, 2010.
[9] V. Rajabi and E. Amani, "A computational study of swirl number effects on entropy generation in gas turbine combustors," Heat Transfer Engineering, vol. 40, no. 3-4, pp. 346-361, 2019.
[10] C. Zong, Y. Lyu, D. Guo, C. Li, and T. Zhu, "Experimental and numerical study on emission characteristics of the double annular swirler under different pilot fuel ratios," in Turbo Expo: Power for Land, Sea, and Air, vol. 51067, p. V04BT04A001, 2018.
[11] S. Karuppannan, B. Mehul, G. Sivaramakrishna, R. D. Navindgi, and N. Muthuveerappan, "CFD analyses of flow in a gas turbine combustor swirl cup," in Gas Turbine India Conference, vol. 58509, p. V001T04A009, 2017.
[12] "Gas turbine unit GTD25HU80.09 engine DU80 combustion chamber characteristics," State Gas Turbine Research & Production Complex "ZORYA"-"MASHPROEKT", 89995ПР3С-1-2-3.