Flamelet LES of a semi-industrial pulverized coal furnace

Rieth, Martin; Proch, Fabian; Rabaçal, M.; Franchetti, Benjamin; Marincola, F. Cavallo; Kempf, Andreas

doi:10.1016/j.combustflame.2016.07.013

Cited by 87 publications

(36 citation statements)

References 62 publications

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“…The simulations are carried out with the in-house code PsiPhi that has been developed at Imperial College in London and at the university of Duisburg-Essen by Kempf and coworkers (Lipkowicz et al 2019;Inanc and Kempf 2019;Cifuentes et al 2019;Rieth et al 2016). PsiPhi solves the fully compressible set of Favre-filtered conservation equations for mass, momentum, total absolute internal energy and partial densities to simulate reactive flow problems:…”

Section: Codementioning

confidence: 99%

Numerical Investigation of Remote Ignition in Shock Tubes

Lipkowicz

Nativel

Cooper

et al. 2020

Flow Turbulence Combust

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Highly resolved two- and three-dimensional computational fluid dynamics (CFD) simulations are presented for shock-tube experiments containing hydrogen/oxygen (H2/O2) mixtures, to investigate mechanisms leading to remote ignition. The results of the reactive cases are compared against experimental results from Meyer and Oppenheim (Proc Combust Inst 13(1): 1153–1164, 1971. 10.1016/s0082-0784(71)80112-1) and Hanson et al. (Combust Flame 160(9): 1550–1558, 2013. 10.1016/j.combustflame.2013.03.026). The results of the non-reactive case are compared against shock tube experiments, recently carried out in Duisburg and Texas. The computational domain covers the end-wall region of the shock tube and applies high order numerics featuring an all-speed approximate Riemann scheme, combined with a 5th order interpolation scheme. Direct chemistry is employed using detailed reaction mechanisms with 11 species and up to 40 reactions, on a grid with up to 2.2 billion cells. Additional two-dimensional simulations are performed for non-reactive conditions to validate the treatment of boundary-layer effects at the inlet of the computational domain. The computational domain covers a region at the end part of the shock tube. The ignition process is analyzed by fields of localized, expected ignition times. Instantaneous fields of temperature, pressure, entropy, and dissipation rate are presented to explain the flow dynamics, specifically in the case of a bifurcated reflected shock. In all cases regions with locally increased temperatures were observed, reducing the local ignition-delay time in areas away from the end wall significantly, thus compensating for the late compression by the reflected shock and therefore leading for first ignition at a remote location, i.e., away from the end wall where the ignition would occur under ideal conditions. In cases without a bifurcated reflected shock, the temperature increase results from shock attenuation. In cases with a bifurcated reflected shock, the formation of a second normal shock and shear near the slip line is found to be crucial for the remote ignition to take place. Overall, the two- and three-dimensional simulations were found to qualitatively explain the occurrence of remote ignition and to be quantitatively correct, implying that they include the correct physics.

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Section: Codementioning

confidence: 99%

Numerical Investigation of Remote Ignition in Shock Tubes

Lipkowicz

Nativel

Cooper

et al. 2020

Flow Turbulence Combust

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“…Classically, turbulence closures for coal flames have been obtained in the Reynolds-Averaged Navier Stokes (RANS) framework [2]. More recently the potentially higher predictive capability of LES approaches for turbulence modelling has been investigated, where mostly flamelet approaches have been employed to model subgrid scale turbulence-chemistry interactions [3][4][5]. However, flamelet-LES modelling of PCC flames is not straightforward, since the mixing of several fuel (volatiles and char off-gases) and oxidiser streams needs to be accurately described [6] and because strong enthalpy changes due to gas-solid heat transfer must be considered [7].…”

Section: Recent Work On Pcc Modellingmentioning

confidence: 99%

Detailed simulations for flamelet modelling of SO_x formation from coal

Wen

Stein

Debiagi

et al. 2019

Proc Appl Math and Mech

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“…The in-house code PsiPhi [18,25,[39][40][41][42][43] was used to solve the implicitly filtered, low-Mach number Navier Stokes equations for a variable density flow. PsiPhi ensures continuity by a pressure-correction scheme using a projection method.…”

Section: Numerical Setupmentioning

confidence: 99%

A Large Eddy Simulation Study on the Effect of Devolatilization Modelling and Char Combustion Mode Modelling on the Structure of a Large-Scale, Biomass and Coal Co-Fired Flame

Rabaçal

Costa

Vascellari

et al. 2018

Journal of Combustion

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This work focuses on the impact of the devolatilization and char combustion mode modelling on the structure of a large-scale, biomass and coal co-fired flame using large eddy simulations. The coal modelling framework previously developed for the simulation of combustion in large-scale facilities is extended for biomass capabilities. An iterative procedure is used to obtain devolatilization kinetics of coal and biomass for the test-case specific fuels and heating conditions. This is achieved by calibrating the model constants of two empirical models: the single first-order model and the distributed activation energy model. The reference data for calibration are devolatilization yields obtained with predictive coal and biomass multistep kinetic mechanisms. The variation of both particle density and diameter during char combustion is governed by the conversion mode, which is modelled using two approaches: the power law using a constant parameter that assumes a constant mode during char combustion and a constant-free model that considers a variable mode during combustion. Three numerical cases are considered: single first-order reaction with constant char combustion mode, distributed activation energy with constant char combustion mode, and single first-order reaction with variable char combustion mode. The numerical predictions from the large eddy simulations are compared with experimental results of a high co-firing rate large-scale laboratory flame of coal and biomass. Furthermore, results from single particle conversion under idealised conditions, isolating the effects of turbulence, are presented to assist the interpretation of the predictions obtained with large eddy simulations. The effects of the devolatilization and conversion mode modelling on the flame lift-off, flame length, and spatial distribution and radial profiles of O2 and CO2 are presented and discussed. Both the devolatilization and conversion mode modelling have a significant effect on the conversion of particles under idealised conditions. The large eddy simulations results show that the devolatilization model has a strong impact on the flame structure, but not on the flame lift-off. On the other hand, for the tested numerical conditions, the char combustion mode model has a marginal impact on the predicted results.

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Flamelet LES of a semi-industrial pulverized coal furnace

Cited by 87 publications

References 62 publications

Numerical Investigation of Remote Ignition in Shock Tubes

Numerical Investigation of Remote Ignition in Shock Tubes

Detailed simulations for flamelet modelling of SO_x formation from coal

A Large Eddy Simulation Study on the Effect of Devolatilization Modelling and Char Combustion Mode Modelling on the Structure of a Large-Scale, Biomass and Coal Co-Fired Flame

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Flamelet LES of a semi-industrial pulverized coal furnace

Cited by 87 publications

References 62 publications

Numerical Investigation of Remote Ignition in Shock Tubes

Numerical Investigation of Remote Ignition in Shock Tubes

Detailed simulations for flamelet modelling of SOx formation from coal

A Large Eddy Simulation Study on the Effect of Devolatilization Modelling and Char Combustion Mode Modelling on the Structure of a Large-Scale, Biomass and Coal Co-Fired Flame

Contact Info

Product

Resources

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Detailed simulations for flamelet modelling of SO_x formation from coal