Towards a generic, reliable CFD modelling methodology for waste-fired grate boilers

Boštjan Rajh, Chungen Yin, Niko Samec, Matjaž Hriberšek, Matej Zadravec

Research output: Contribution to conference without publisher/journalPaper without publisher/journalResearchpeer-review

Abstract

Computational Fluid Dynamics (CFD) is increasingly used in industry for detailed understanding of the combustion process and for appropriate design and optimization of Waste–to–Energy (WtE) plants. In this paper, CFD modelling of waste wood combustion in a 13 MW grate-fired boiler in a WtE plant is presented. To reduce the risk of slagging, optimize the temperature control and enhance turbulent mixing, part of the flue gas is recycled into the grate boiler. In the simulation, a 1D in–house bed model is developed to simulate the conversion of the waste wood in the fuel bed on the grate, which provides the appropriate inlet boundary condition for the freeboard 3D CFD simulation. Additionally, a refined WSGGM (weighted sum of gray gases model) of greater accuracy, completeness and applicability is proposed and implemented into the CFD model via user defined functions (UDF) to better address the impacts of the increased CO2 and H2O vapour concentrations on radiative heat transfer in the boiler. The impacts of full buoyancy on turbulence are also investigated. As a validation effort, the temperature profiles at different ports inside the furnace are measured and the experimental values are compared with the CFD results.
Original languageEnglish
Publication dateSep 2015
Number of pages16
Publication statusPublished - Sep 2015
Event10th Conference on Sustainable Development of Energy, Water and Environment Systems - Dubrovnik, Croatia
Duration: 27 Sep 20143 Oct 2014

Conference

Conference10th Conference on Sustainable Development of Energy, Water and Environment Systems
CountryCroatia
CityDubrovnik
Period27/09/201403/10/2014

Fingerprint

Boilers
Computational fluid dynamics
Wood wastes
Buoyancy
Flue gases
Temperature control
Dynamic models
Furnaces
Turbulence
Vapors
Boundary conditions
Heat transfer
Computer simulation
Gases
Industry
Temperature

Keywords

  • Waste–fired grate boiler
  • Bed model
  • Radiation modelling
  • Computational Fluid Dynamics (CFD)

Cite this

Rajh, B., Yin, C., Samec, N., Hriberšek, M., & Zadravec, M. (2015). Towards a generic, reliable CFD modelling methodology for waste-fired grate boilers. Paper presented at 10th Conference on Sustainable Development of Energy, Water and Environment Systems, Dubrovnik, Croatia.
Rajh, Boštjan ; Yin, Chungen ; Samec, Niko ; Hriberšek, Matjaž ; Zadravec, Matej. / Towards a generic, reliable CFD modelling methodology for waste-fired grate boilers. Paper presented at 10th Conference on Sustainable Development of Energy, Water and Environment Systems, Dubrovnik, Croatia.16 p.
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Rajh, B, Yin, C, Samec, N, Hriberšek, M & Zadravec, M 2015, 'Towards a generic, reliable CFD modelling methodology for waste-fired grate boilers' Paper presented at, Dubrovnik, Croatia, 27/09/2014 - 03/10/2014, .

Towards a generic, reliable CFD modelling methodology for waste-fired grate boilers. / Rajh, Boštjan; Yin, Chungen; Samec, Niko; Hriberšek, Matjaž; Zadravec, Matej.

2015. Paper presented at 10th Conference on Sustainable Development of Energy, Water and Environment Systems, Dubrovnik, Croatia.

Research output: Contribution to conference without publisher/journalPaper without publisher/journalResearchpeer-review

TY - CONF

T1 - Towards a generic, reliable CFD modelling methodology for waste-fired grate boilers

AU - Rajh, Boštjan

AU - Yin, Chungen

AU - Samec, Niko

AU - Hriberšek, Matjaž

AU - Zadravec, Matej

PY - 2015/9

Y1 - 2015/9

N2 - Computational Fluid Dynamics (CFD) is increasingly used in industry for detailed understanding of the combustion process and for appropriate design and optimization of Waste–to–Energy (WtE) plants. In this paper, CFD modelling of waste wood combustion in a 13 MW grate-fired boiler in a WtE plant is presented. To reduce the risk of slagging, optimize the temperature control and enhance turbulent mixing, part of the flue gas is recycled into the grate boiler. In the simulation, a 1D in–house bed model is developed to simulate the conversion of the waste wood in the fuel bed on the grate, which provides the appropriate inlet boundary condition for the freeboard 3D CFD simulation. Additionally, a refined WSGGM (weighted sum of gray gases model) of greater accuracy, completeness and applicability is proposed and implemented into the CFD model via user defined functions (UDF) to better address the impacts of the increased CO2 and H2O vapour concentrations on radiative heat transfer in the boiler. The impacts of full buoyancy on turbulence are also investigated. As a validation effort, the temperature profiles at different ports inside the furnace are measured and the experimental values are compared with the CFD results.

AB - Computational Fluid Dynamics (CFD) is increasingly used in industry for detailed understanding of the combustion process and for appropriate design and optimization of Waste–to–Energy (WtE) plants. In this paper, CFD modelling of waste wood combustion in a 13 MW grate-fired boiler in a WtE plant is presented. To reduce the risk of slagging, optimize the temperature control and enhance turbulent mixing, part of the flue gas is recycled into the grate boiler. In the simulation, a 1D in–house bed model is developed to simulate the conversion of the waste wood in the fuel bed on the grate, which provides the appropriate inlet boundary condition for the freeboard 3D CFD simulation. Additionally, a refined WSGGM (weighted sum of gray gases model) of greater accuracy, completeness and applicability is proposed and implemented into the CFD model via user defined functions (UDF) to better address the impacts of the increased CO2 and H2O vapour concentrations on radiative heat transfer in the boiler. The impacts of full buoyancy on turbulence are also investigated. As a validation effort, the temperature profiles at different ports inside the furnace are measured and the experimental values are compared with the CFD results.

KW - Waste–fired grate boiler

KW - Bed model

KW - Radiation modelling

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M3 - Paper without publisher/journal

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Rajh B, Yin C, Samec N, Hriberšek M, Zadravec M. Towards a generic, reliable CFD modelling methodology for waste-fired grate boilers. 2015. Paper presented at 10th Conference on Sustainable Development of Energy, Water and Environment Systems, Dubrovnik, Croatia.