The Experts below are selected from a list of 4305 Experts worldwide ranked by ideXlab platform
Mohamed Pourkashanian - One of the best experts on this subject based on the ideXlab platform.
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Pulverised Coal and biomass co-combustion: particle flow modelling in a swirl burner
Journal of the Energy Institute, 2013Co-Authors: K.j. Larsen, Mohamed Pourkashanian, A. D. Burns, Sreenivasa Rao Gubba, Derek B. Ingham, Alan WilliamsAbstract:The co-combustion of Pulverised Coal and biomass is increasingly being used for environmental reasons, and a number of computational fluid dynamic investigations are being undertaken to understand the details of the combustion process. These investigations assume that the particle flow entering the burner is uniformly distributed across the burner mouth or inlet. In this paper, this assumption is examined for an industrial burner by numerically simulating the fuel particle flows in the tube leading to the burner mouth. While there is evidence of maldistribution of the particles at the burner mouth, it is concluded from the flame data that this effect does not significantly influence the combustion flame in the furnace for the cases investigated.
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Numerical modelling of the co-firing of Pulverised Coal and straw in a 300 MWe tangentially fired boiler
Fuel Processing Technology, 2012Co-Authors: Sreenivasa Rao Gubba, Alan Williams, Mohamed Pourkashanian, K.j. Larsen, Db B. Ingham, Houzhang Tan, Hao ZhouAbstract:Abstract The co-firing of Pulverised Coal/biomass in power generation plants is receiving considerable attention due to its influence in reducing all forms of emissions. Unlike Coal, milled biomass, such as straw, may contain large particles of different sizes and shapes, which can have an impact on the combustion characteristics and emissions. Computational fluid dynamics (CFD) is often used to understand the influence of large biomass particles in a furnace. However, most CFD sub-models simplify heat transfer effects within the particles during combustion. In this paper a particle heat-up model, which considers the influence of thermal gradients within large biomass particles, is applied to a co-firing Coal/biomass simulation in a tangentially fired furnace with up to 12% thermal biomass loading. Different sizes of biomass particles of non-spherical shape and their impact on the combustion behavior have been investigated. The influence of the particle size and shape distribution on the combustion characteristics and emissions was found to be significant. The computed results were found to be in good agreement with the experimental data.
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Pulverised Coal/biomass co-fire modelling in a full scale corner-fired boiler
2011Co-Authors: Gubba, Mohamed Pourkashanian, K.j. Larsen, Db B. Ingham, Houzhang Tan, Allan P. O. WilliamsAbstract:The practice of co-firing biomass in full-scale Coal utility plants is gradually increasing. This is mainly because of the benefits associated in reducing the Coal based CO2 and biomass based SOx and NOx emissions. Significant numbers of existing Coal power stations are suitable for co-firing with small/no changes in the original infrastructures. In order to demonstrate this, combustion modelling of a 300MWe, widely used tangentially fired furnace for Pulverised Coal has been undertaken in this work. Typical Chinese fuels, Huating Coal and wheat straw, were burned at 100% Coal and under Coal/wheat straw co-firing (up to ≈12.5% on a thermal basis). In the experiments, wheat straw has been handled by the existing Coal mills and feeding system to a set of dedicated burners. CFD predications are in good agreement in general with the measured data such as temperature, furnace exit oxygen, unburnt carbon in the ash and NOx emissions.
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les modelling of air and oxy fuel Pulverised Coal combustion impact on flame properties
Proceedings of the Combustion Institute, 2011Co-Authors: P J Edge, Sreenivasa Rao Gubba, Mohamed Pourkashanian, R Porter, Alan WilliamsAbstract:Abstract Large eddy simulations (LES) are used in a CFD model to simulate air- and oxy-fired Pulverised Coal combustion in a 0.5 MWth combustion test facility. Simulations are carried out using two different burners, namely, a triple-staged low-NOx wall fired burner and an IFRF Aerodynamically Air-Staged Burner (AASB). Non-gray radiation is considered in order to deal with the spectral nature of absorption and emission by high levels of combustion products in oxy-fuel combustion. Predictions using LES are compared with Reynolds-averaged Navier–Stokes (RANS) calculations using variants of the k-e model for turbulence and against available experimental measurements. The results suggest that LES can offer improvements over RANS in predicting recirculation zones and flame properties of the Pulverised combustion systems investigated. Flame flickering frequencies from the LES simulations are calculated and validated against available measurements. The work presented demonstrates the potential importance of using LES turbulence models for Coal combustion.
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LES modelling of air and oxy-fuel Pulverised Coal combustion—impact on flame properties
Proceedings of the Combustion Institute, 2011Co-Authors: P J Edge, Mohamed Pourkashanian, Sreenivasa Rao Gubba, R Porter, Allan P. O. WilliamsAbstract:Abstract Large eddy simulations (LES) are used in a CFD model to simulate air- and oxy-fired Pulverised Coal combustion in a 0.5 MWth combustion test facility. Simulations are carried out using two different burners, namely, a triple-staged low-NOx wall fired burner and an IFRF Aerodynamically Air-Staged Burner (AASB). Non-gray radiation is considered in order to deal with the spectral nature of absorption and emission by high levels of combustion products in oxy-fuel combustion. Predictions using LES are compared with Reynolds-averaged Navier–Stokes (RANS) calculations using variants of the k-e model for turbulence and against available experimental measurements. The results suggest that LES can offer improvements over RANS in predicting recirculation zones and flame properties of the Pulverised combustion systems investigated. Flame flickering frequencies from the LES simulations are calculated and validated against available measurements. The work presented demonstrates the potential importance of using LES turbulence models for Coal combustion.
Allan P. O. Williams - One of the best experts on this subject based on the ideXlab platform.
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LES modelling of air and oxy-fuel Pulverised Coal combustion—impact on flame properties
Proceedings of the Combustion Institute, 2011Co-Authors: P J Edge, Mohamed Pourkashanian, Sreenivasa Rao Gubba, R Porter, Allan P. O. WilliamsAbstract:Abstract Large eddy simulations (LES) are used in a CFD model to simulate air- and oxy-fired Pulverised Coal combustion in a 0.5 MWth combustion test facility. Simulations are carried out using two different burners, namely, a triple-staged low-NOx wall fired burner and an IFRF Aerodynamically Air-Staged Burner (AASB). Non-gray radiation is considered in order to deal with the spectral nature of absorption and emission by high levels of combustion products in oxy-fuel combustion. Predictions using LES are compared with Reynolds-averaged Navier–Stokes (RANS) calculations using variants of the k-e model for turbulence and against available experimental measurements. The results suggest that LES can offer improvements over RANS in predicting recirculation zones and flame properties of the Pulverised combustion systems investigated. Flame flickering frequencies from the LES simulations are calculated and validated against available measurements. The work presented demonstrates the potential importance of using LES turbulence models for Coal combustion.
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Pulverised Coal/biomass co-fire modelling in a full scale corner-fired boiler
2011Co-Authors: Gubba, Mohamed Pourkashanian, K.j. Larsen, Db B. Ingham, Houzhang Tan, Allan P. O. WilliamsAbstract:The practice of co-firing biomass in full-scale Coal utility plants is gradually increasing. This is mainly because of the benefits associated in reducing the Coal based CO2 and biomass based SOx and NOx emissions. Significant numbers of existing Coal power stations are suitable for co-firing with small/no changes in the original infrastructures. In order to demonstrate this, combustion modelling of a 300MWe, widely used tangentially fired furnace for Pulverised Coal has been undertaken in this work. Typical Chinese fuels, Huating Coal and wheat straw, were burned at 100% Coal and under Coal/wheat straw co-firing (up to ≈12.5% on a thermal basis). In the experiments, wheat straw has been handled by the existing Coal mills and feeding system to a set of dedicated burners. CFD predications are in good agreement in general with the measured data such as temperature, furnace exit oxygen, unburnt carbon in the ash and NOx emissions.
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Prediction of NOx and unburned carbon in ash in highly staged Pulverised Coal furnace using overfire air
Journal of the Energy Institute, 2010Co-Authors: Julian R. Jones, Mohamed Pourkashanian, D. J. Waldron, Allan P. O. WilliamsAbstract:Abstract Abstract NOx emissions from power plants burning Pulverised Coal are subject to increasingly stringent regulations, and this has a consequential effect on the amount of unburned carbon (UBC) produced. The prediction of both is important, and a number of modelling techniques are available, but there could be difficulties especially under highly staged combustion. This is because these regions have low oxygen concentrations where char gasification reactions might take place in addition to the normal combustion. The present paper discusses the role of these reactions mainly within a staged tangentially T fired furnace, which uses overfire air for NOx reduction, but it also considered a wall fired case. Predictions for UBC and NOx in these furnaces, which are represented by a series of slices, were made with and without the gasification equations and are compared with test data from furnaces. These results indicate that the char gasification reactions play only a small role even under highly staged c...
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Co-firing Pulverised Coal and biomass: a modeling approach
Proceedings of the Combustion Institute, 2005Co-Authors: R.i. Backreedy, Mohamed Pourkashanian, Jenny M. Jones, L. M. Fletcher, Allan P. O. WilliamsAbstract:Abstract A CFD modelling study has been undertaken to examine the co-firing of Pulverised Coal and biomass with particular regard to the burnout of the larger diameter biomass particles. Computations were based on a research combustion facility that replicates an industrial Coal-fired power station. Three percent, by mass, of pinewood was blended with a bituminous UK Coal, and the effects of the wood particle size and shape on the burnout of the combined wood and Coal char were investigated. The effect of varying the devolatilisation and char combustion rate constants for the biomass component in the blend was also investigated. It was concluded that the combustion of small (200 μm) wood particles was rapid but the rate of combustion of larger particles was dependent on their composition, size, and shape.
Alan Williams - One of the best experts on this subject based on the ideXlab platform.
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Pulverised Coal and biomass co-combustion: particle flow modelling in a swirl burner
Journal of the Energy Institute, 2013Co-Authors: K.j. Larsen, Mohamed Pourkashanian, A. D. Burns, Sreenivasa Rao Gubba, Derek B. Ingham, Alan WilliamsAbstract:The co-combustion of Pulverised Coal and biomass is increasingly being used for environmental reasons, and a number of computational fluid dynamic investigations are being undertaken to understand the details of the combustion process. These investigations assume that the particle flow entering the burner is uniformly distributed across the burner mouth or inlet. In this paper, this assumption is examined for an industrial burner by numerically simulating the fuel particle flows in the tube leading to the burner mouth. While there is evidence of maldistribution of the particles at the burner mouth, it is concluded from the flame data that this effect does not significantly influence the combustion flame in the furnace for the cases investigated.
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Numerical modelling of the co-firing of Pulverised Coal and straw in a 300 MWe tangentially fired boiler
Fuel Processing Technology, 2012Co-Authors: Sreenivasa Rao Gubba, Alan Williams, Mohamed Pourkashanian, K.j. Larsen, Db B. Ingham, Houzhang Tan, Hao ZhouAbstract:Abstract The co-firing of Pulverised Coal/biomass in power generation plants is receiving considerable attention due to its influence in reducing all forms of emissions. Unlike Coal, milled biomass, such as straw, may contain large particles of different sizes and shapes, which can have an impact on the combustion characteristics and emissions. Computational fluid dynamics (CFD) is often used to understand the influence of large biomass particles in a furnace. However, most CFD sub-models simplify heat transfer effects within the particles during combustion. In this paper a particle heat-up model, which considers the influence of thermal gradients within large biomass particles, is applied to a co-firing Coal/biomass simulation in a tangentially fired furnace with up to 12% thermal biomass loading. Different sizes of biomass particles of non-spherical shape and their impact on the combustion behavior have been investigated. The influence of the particle size and shape distribution on the combustion characteristics and emissions was found to be significant. The computed results were found to be in good agreement with the experimental data.
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les modelling of air and oxy fuel Pulverised Coal combustion impact on flame properties
Proceedings of the Combustion Institute, 2011Co-Authors: P J Edge, Sreenivasa Rao Gubba, Mohamed Pourkashanian, R Porter, Alan WilliamsAbstract:Abstract Large eddy simulations (LES) are used in a CFD model to simulate air- and oxy-fired Pulverised Coal combustion in a 0.5 MWth combustion test facility. Simulations are carried out using two different burners, namely, a triple-staged low-NOx wall fired burner and an IFRF Aerodynamically Air-Staged Burner (AASB). Non-gray radiation is considered in order to deal with the spectral nature of absorption and emission by high levels of combustion products in oxy-fuel combustion. Predictions using LES are compared with Reynolds-averaged Navier–Stokes (RANS) calculations using variants of the k-e model for turbulence and against available experimental measurements. The results suggest that LES can offer improvements over RANS in predicting recirculation zones and flame properties of the Pulverised combustion systems investigated. Flame flickering frequencies from the LES simulations are calculated and validated against available measurements. The work presented demonstrates the potential importance of using LES turbulence models for Coal combustion.
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les modelling of air and oxy fuel Pulverised Coal combustion impact on flame properties
Proceedings of the Combustion Institute, 2011Co-Authors: P J Edge, Sreenivasa Rao Gubba, Mohamed Pourkashanian, R Porter, Alan WilliamsAbstract:Abstract Large eddy simulations (LES) are used in a CFD model to simulate air- and oxy-fired Pulverised Coal combustion in a 0.5 MWth combustion test facility. Simulations are carried out using two different burners, namely, a triple-staged low-NOx wall fired burner and an IFRF Aerodynamically Air-Staged Burner (AASB). Non-gray radiation is considered in order to deal with the spectral nature of absorption and emission by high levels of combustion products in oxy-fuel combustion. Predictions using LES are compared with Reynolds-averaged Navier–Stokes (RANS) calculations using variants of the k-e model for turbulence and against available experimental measurements. The results suggest that LES can offer improvements over RANS in predicting recirculation zones and flame properties of the Pulverised combustion systems investigated. Flame flickering frequencies from the LES simulations are calculated and validated against available measurements. The work presented demonstrates the potential importance of using LES turbulence models for Coal combustion.
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Combustion of Pulverised Coal and biomass
Progress in Energy and Combustion Science, 2001Co-Authors: Alan Williams, Mohamed Pourkashanian, Jenny M. JonesAbstract:This review paper is concerned with the current status of the understanding of the combustion of Pulverised Coal and Pulverised biomass from the viewpoint of computer modelling. Whilst a knowledge of the underpinning science is of vital importance it's translation into applicable computer useable equations or computer data base libraries is of vital importance. A review is given of the current status of sub-models for the combustion of Pulverised Coal. Much of the information available for Coal is transferable to biomass combustion although there are still areas where there is a lack of information.
Sreenivasa Rao Gubba - One of the best experts on this subject based on the ideXlab platform.
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Pulverised Coal and biomass co-combustion: particle flow modelling in a swirl burner
Journal of the Energy Institute, 2013Co-Authors: K.j. Larsen, Mohamed Pourkashanian, A. D. Burns, Sreenivasa Rao Gubba, Derek B. Ingham, Alan WilliamsAbstract:The co-combustion of Pulverised Coal and biomass is increasingly being used for environmental reasons, and a number of computational fluid dynamic investigations are being undertaken to understand the details of the combustion process. These investigations assume that the particle flow entering the burner is uniformly distributed across the burner mouth or inlet. In this paper, this assumption is examined for an industrial burner by numerically simulating the fuel particle flows in the tube leading to the burner mouth. While there is evidence of maldistribution of the particles at the burner mouth, it is concluded from the flame data that this effect does not significantly influence the combustion flame in the furnace for the cases investigated.
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Numerical modelling of the co-firing of Pulverised Coal and straw in a 300 MWe tangentially fired boiler
Fuel Processing Technology, 2012Co-Authors: Sreenivasa Rao Gubba, Alan Williams, Mohamed Pourkashanian, K.j. Larsen, Db B. Ingham, Houzhang Tan, Hao ZhouAbstract:Abstract The co-firing of Pulverised Coal/biomass in power generation plants is receiving considerable attention due to its influence in reducing all forms of emissions. Unlike Coal, milled biomass, such as straw, may contain large particles of different sizes and shapes, which can have an impact on the combustion characteristics and emissions. Computational fluid dynamics (CFD) is often used to understand the influence of large biomass particles in a furnace. However, most CFD sub-models simplify heat transfer effects within the particles during combustion. In this paper a particle heat-up model, which considers the influence of thermal gradients within large biomass particles, is applied to a co-firing Coal/biomass simulation in a tangentially fired furnace with up to 12% thermal biomass loading. Different sizes of biomass particles of non-spherical shape and their impact on the combustion behavior have been investigated. The influence of the particle size and shape distribution on the combustion characteristics and emissions was found to be significant. The computed results were found to be in good agreement with the experimental data.
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les modelling of air and oxy fuel Pulverised Coal combustion impact on flame properties
Proceedings of the Combustion Institute, 2011Co-Authors: P J Edge, Sreenivasa Rao Gubba, Mohamed Pourkashanian, R Porter, Alan WilliamsAbstract:Abstract Large eddy simulations (LES) are used in a CFD model to simulate air- and oxy-fired Pulverised Coal combustion in a 0.5 MWth combustion test facility. Simulations are carried out using two different burners, namely, a triple-staged low-NOx wall fired burner and an IFRF Aerodynamically Air-Staged Burner (AASB). Non-gray radiation is considered in order to deal with the spectral nature of absorption and emission by high levels of combustion products in oxy-fuel combustion. Predictions using LES are compared with Reynolds-averaged Navier–Stokes (RANS) calculations using variants of the k-e model for turbulence and against available experimental measurements. The results suggest that LES can offer improvements over RANS in predicting recirculation zones and flame properties of the Pulverised combustion systems investigated. Flame flickering frequencies from the LES simulations are calculated and validated against available measurements. The work presented demonstrates the potential importance of using LES turbulence models for Coal combustion.
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LES modelling of air and oxy-fuel Pulverised Coal combustion—impact on flame properties
Proceedings of the Combustion Institute, 2011Co-Authors: P J Edge, Mohamed Pourkashanian, Sreenivasa Rao Gubba, R Porter, Allan P. O. WilliamsAbstract:Abstract Large eddy simulations (LES) are used in a CFD model to simulate air- and oxy-fired Pulverised Coal combustion in a 0.5 MWth combustion test facility. Simulations are carried out using two different burners, namely, a triple-staged low-NOx wall fired burner and an IFRF Aerodynamically Air-Staged Burner (AASB). Non-gray radiation is considered in order to deal with the spectral nature of absorption and emission by high levels of combustion products in oxy-fuel combustion. Predictions using LES are compared with Reynolds-averaged Navier–Stokes (RANS) calculations using variants of the k-e model for turbulence and against available experimental measurements. The results suggest that LES can offer improvements over RANS in predicting recirculation zones and flame properties of the Pulverised combustion systems investigated. Flame flickering frequencies from the LES simulations are calculated and validated against available measurements. The work presented demonstrates the potential importance of using LES turbulence models for Coal combustion.
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les modelling of air and oxy fuel Pulverised Coal combustion impact on flame properties
Proceedings of the Combustion Institute, 2011Co-Authors: P J Edge, Sreenivasa Rao Gubba, Mohamed Pourkashanian, R Porter, Alan WilliamsAbstract:Abstract Large eddy simulations (LES) are used in a CFD model to simulate air- and oxy-fired Pulverised Coal combustion in a 0.5 MWth combustion test facility. Simulations are carried out using two different burners, namely, a triple-staged low-NOx wall fired burner and an IFRF Aerodynamically Air-Staged Burner (AASB). Non-gray radiation is considered in order to deal with the spectral nature of absorption and emission by high levels of combustion products in oxy-fuel combustion. Predictions using LES are compared with Reynolds-averaged Navier–Stokes (RANS) calculations using variants of the k-e model for turbulence and against available experimental measurements. The results suggest that LES can offer improvements over RANS in predicting recirculation zones and flame properties of the Pulverised combustion systems investigated. Flame flickering frequencies from the LES simulations are calculated and validated against available measurements. The work presented demonstrates the potential importance of using LES turbulence models for Coal combustion.
K.j. Larsen - One of the best experts on this subject based on the ideXlab platform.
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Pulverised Coal and biomass co-combustion: particle flow modelling in a swirl burner
Journal of the Energy Institute, 2013Co-Authors: K.j. Larsen, Mohamed Pourkashanian, A. D. Burns, Sreenivasa Rao Gubba, Derek B. Ingham, Alan WilliamsAbstract:The co-combustion of Pulverised Coal and biomass is increasingly being used for environmental reasons, and a number of computational fluid dynamic investigations are being undertaken to understand the details of the combustion process. These investigations assume that the particle flow entering the burner is uniformly distributed across the burner mouth or inlet. In this paper, this assumption is examined for an industrial burner by numerically simulating the fuel particle flows in the tube leading to the burner mouth. While there is evidence of maldistribution of the particles at the burner mouth, it is concluded from the flame data that this effect does not significantly influence the combustion flame in the furnace for the cases investigated.
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Numerical modelling of the co-firing of Pulverised Coal and straw in a 300 MWe tangentially fired boiler
Fuel Processing Technology, 2012Co-Authors: Sreenivasa Rao Gubba, Alan Williams, Mohamed Pourkashanian, K.j. Larsen, Db B. Ingham, Houzhang Tan, Hao ZhouAbstract:Abstract The co-firing of Pulverised Coal/biomass in power generation plants is receiving considerable attention due to its influence in reducing all forms of emissions. Unlike Coal, milled biomass, such as straw, may contain large particles of different sizes and shapes, which can have an impact on the combustion characteristics and emissions. Computational fluid dynamics (CFD) is often used to understand the influence of large biomass particles in a furnace. However, most CFD sub-models simplify heat transfer effects within the particles during combustion. In this paper a particle heat-up model, which considers the influence of thermal gradients within large biomass particles, is applied to a co-firing Coal/biomass simulation in a tangentially fired furnace with up to 12% thermal biomass loading. Different sizes of biomass particles of non-spherical shape and their impact on the combustion behavior have been investigated. The influence of the particle size and shape distribution on the combustion characteristics and emissions was found to be significant. The computed results were found to be in good agreement with the experimental data.
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Pulverised Coal/biomass co-fire modelling in a full scale corner-fired boiler
2011Co-Authors: Gubba, Mohamed Pourkashanian, K.j. Larsen, Db B. Ingham, Houzhang Tan, Allan P. O. WilliamsAbstract:The practice of co-firing biomass in full-scale Coal utility plants is gradually increasing. This is mainly because of the benefits associated in reducing the Coal based CO2 and biomass based SOx and NOx emissions. Significant numbers of existing Coal power stations are suitable for co-firing with small/no changes in the original infrastructures. In order to demonstrate this, combustion modelling of a 300MWe, widely used tangentially fired furnace for Pulverised Coal has been undertaken in this work. Typical Chinese fuels, Huating Coal and wheat straw, were burned at 100% Coal and under Coal/wheat straw co-firing (up to ≈12.5% on a thermal basis). In the experiments, wheat straw has been handled by the existing Coal mills and feeding system to a set of dedicated burners. CFD predications are in good agreement in general with the measured data such as temperature, furnace exit oxygen, unburnt carbon in the ash and NOx emissions.
