The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Hari B Vuthaluru - One of the best experts on this subject based on the ideXlab platform.
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a kinetic empirical model for particle size distribution evolution during Pulverised Fuel combustion
Fuel, 2010Co-Authors: Kalpit Shah, Christine I. Betrand, Mariusz K. Cieplik, Willem L Van De Kamp, Hari B VuthaluruAbstract:Particle size is an essential parameter in Pulverised Fuel (PF) combustion as many of the problems or further areas of development in these systems are strongly influenced by the Fuel and ash size distribution. This is particularly true for dynamic processes like pollutant formation, corrosion, erosion, slagging and fouling and the related decrease of the combustion and boiler efficiency. The evolution of particle size distribution (PSD) is a complex interaction of various competing chemical and physical transformations. Char oxidation, devolatilization and fragmentation, etc. represent first line physical and chemical transformations which can amend the particle size in the radiation zone. The evolution of the PSD represents the convolution of all of these physical and chemical transformations, operating over the entire size distribution. As a consequence, it is difficult to extract the relative importance of all competing size altering processes from the experiments. Various models such as break-up, thermal stress, shrinking core, percolation and particle-population model have been developed by incorporating numerous ash transformation mechanisms to predict the particle size evolution during the Pulverised Fuel combustion. The present work describes an adaptation of the numerical kinetic-based particle-population balance for predicting particle size evolution during PF combustion developed by Dunn-Rankin and Mitchell. The model is further simplified analytically and validated against experimental results. Several empirical parameters derived from the experiments are incorporated into the model. The resulting simplified PSD evolution model shows good agreement with literature and experimental results, with maximum 10% absolute standard deviation.
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A kinetic-empirical model for particle size distribution evolution during Pulverised Fuel combustion
Fuel, 2010Co-Authors: Kalpit V. Shah, Christine I. Betrand, Willem L. Van De Kamp, Mariusz K. Cieplik, Hari B VuthaluruAbstract:Particle size is an essential parameter in Pulverised Fuel (PF) combustion as many of the problems or further areas of development in these systems are strongly influenced by the Fuel and ash size distribution. This is particularly true for dynamic processes like pollutant formation, corrosion, erosion, slagging and fouling and the related decrease of the combustion and boiler efficiency. The evolution of particle size distribution (PSD) is a complex interaction of various competing chemical and physical transformations. Char oxidation, devolatilization and fragmentation, etc. represent first line physical and chemical transformations which can amend the particle size in the radiation zone. The evolution of the PSD represents the convolution of all of these physical and chemical transformations, operating over the entire size distribution. As a consequence, it is difficult to extract the relative importance of all competing size altering processes from the experiments. Various models such as break-up, thermal stress, shrinking core, percolation and particle-population model have been developed by incorporating numerous ash transformation mechanisms to predict the particle size evolution during the Pulverised Fuel combustion. The present work describes an adaptation of the numerical kinetic-based particle-population balance for predicting particle size evolution during PF combustion developed by Dunn-Rankin and Mitchell. The model is further simplified analytically and validated against experimental results. Several empirical parameters derived from the experiments are incorporated into the model. The resulting simplified PSD evolution model shows good agreement with literature and experimental results, with maximum 10% absolute standard deviation. Crown Copyright © 2009 Published by Elsevier Ltd. All rights reserved.
Mariusz K. Cieplik - One of the best experts on this subject based on the ideXlab platform.
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ash formation slagging and fouling in biomass co firing in Pulverised Fuel boilers
2011Co-Authors: Mariusz K. Cieplik, Lydia Fryda, W L Van De Kamp, J H A KielAbstract:This chapter gives an overview of the main ash formation and deposition mechanisms for various relevant biomass Fuels, also in blends with selected coals, in Pulverised-Fuel (PF) boilers. The chapter is divided into three sections. In the first, a general outline of the ash formation mechanisms is given. The second section gives a review of experimental and analytical techniques for the (lab-scale) characterisation of Fuels, with the emphasis on the ash-forming elements contents and fate during the combustion. Fuel reactivity and burnout, devolatilisation behaviour, N-release and slagging and fouling propensity are discussed. Also, a detailed overview of the experimental conditions and their relevance for the existing as well as the future technologies is given. Further an outline of diagnostic techniques for the in-boiler characterisation of slagging and fouling is issued. In the third section, key ash-formation phenomena are discussed for various pure biomass Fuels and selected typical coals. This is done on the basis of exemplified results, generated with the techniques discussed in the foregoing section. For slagging and fouling this is also backed up with data from full-scale diagnostic measurements.
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a kinetic empirical model for particle size distribution evolution during Pulverised Fuel combustion
Fuel, 2010Co-Authors: Kalpit Shah, Christine I. Betrand, Mariusz K. Cieplik, Willem L Van De Kamp, Hari B VuthaluruAbstract:Particle size is an essential parameter in Pulverised Fuel (PF) combustion as many of the problems or further areas of development in these systems are strongly influenced by the Fuel and ash size distribution. This is particularly true for dynamic processes like pollutant formation, corrosion, erosion, slagging and fouling and the related decrease of the combustion and boiler efficiency. The evolution of particle size distribution (PSD) is a complex interaction of various competing chemical and physical transformations. Char oxidation, devolatilization and fragmentation, etc. represent first line physical and chemical transformations which can amend the particle size in the radiation zone. The evolution of the PSD represents the convolution of all of these physical and chemical transformations, operating over the entire size distribution. As a consequence, it is difficult to extract the relative importance of all competing size altering processes from the experiments. Various models such as break-up, thermal stress, shrinking core, percolation and particle-population model have been developed by incorporating numerous ash transformation mechanisms to predict the particle size evolution during the Pulverised Fuel combustion. The present work describes an adaptation of the numerical kinetic-based particle-population balance for predicting particle size evolution during PF combustion developed by Dunn-Rankin and Mitchell. The model is further simplified analytically and validated against experimental results. Several empirical parameters derived from the experiments are incorporated into the model. The resulting simplified PSD evolution model shows good agreement with literature and experimental results, with maximum 10% absolute standard deviation.
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A kinetic-empirical model for particle size distribution evolution during Pulverised Fuel combustion
Fuel, 2010Co-Authors: Kalpit V. Shah, Christine I. Betrand, Willem L. Van De Kamp, Mariusz K. Cieplik, Hari B VuthaluruAbstract:Particle size is an essential parameter in Pulverised Fuel (PF) combustion as many of the problems or further areas of development in these systems are strongly influenced by the Fuel and ash size distribution. This is particularly true for dynamic processes like pollutant formation, corrosion, erosion, slagging and fouling and the related decrease of the combustion and boiler efficiency. The evolution of particle size distribution (PSD) is a complex interaction of various competing chemical and physical transformations. Char oxidation, devolatilization and fragmentation, etc. represent first line physical and chemical transformations which can amend the particle size in the radiation zone. The evolution of the PSD represents the convolution of all of these physical and chemical transformations, operating over the entire size distribution. As a consequence, it is difficult to extract the relative importance of all competing size altering processes from the experiments. Various models such as break-up, thermal stress, shrinking core, percolation and particle-population model have been developed by incorporating numerous ash transformation mechanisms to predict the particle size evolution during the Pulverised Fuel combustion. The present work describes an adaptation of the numerical kinetic-based particle-population balance for predicting particle size evolution during PF combustion developed by Dunn-Rankin and Mitchell. The model is further simplified analytically and validated against experimental results. Several empirical parameters derived from the experiments are incorporated into the model. The resulting simplified PSD evolution model shows good agreement with literature and experimental results, with maximum 10% absolute standard deviation. Crown Copyright © 2009 Published by Elsevier Ltd. All rights reserved.
Christine I. Betrand - One of the best experts on this subject based on the ideXlab platform.
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a kinetic empirical model for particle size distribution evolution during Pulverised Fuel combustion
Fuel, 2010Co-Authors: Kalpit Shah, Christine I. Betrand, Mariusz K. Cieplik, Willem L Van De Kamp, Hari B VuthaluruAbstract:Particle size is an essential parameter in Pulverised Fuel (PF) combustion as many of the problems or further areas of development in these systems are strongly influenced by the Fuel and ash size distribution. This is particularly true for dynamic processes like pollutant formation, corrosion, erosion, slagging and fouling and the related decrease of the combustion and boiler efficiency. The evolution of particle size distribution (PSD) is a complex interaction of various competing chemical and physical transformations. Char oxidation, devolatilization and fragmentation, etc. represent first line physical and chemical transformations which can amend the particle size in the radiation zone. The evolution of the PSD represents the convolution of all of these physical and chemical transformations, operating over the entire size distribution. As a consequence, it is difficult to extract the relative importance of all competing size altering processes from the experiments. Various models such as break-up, thermal stress, shrinking core, percolation and particle-population model have been developed by incorporating numerous ash transformation mechanisms to predict the particle size evolution during the Pulverised Fuel combustion. The present work describes an adaptation of the numerical kinetic-based particle-population balance for predicting particle size evolution during PF combustion developed by Dunn-Rankin and Mitchell. The model is further simplified analytically and validated against experimental results. Several empirical parameters derived from the experiments are incorporated into the model. The resulting simplified PSD evolution model shows good agreement with literature and experimental results, with maximum 10% absolute standard deviation.
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A kinetic-empirical model for particle size distribution evolution during Pulverised Fuel combustion
Fuel, 2010Co-Authors: Kalpit V. Shah, Christine I. Betrand, Willem L. Van De Kamp, Mariusz K. Cieplik, Hari B VuthaluruAbstract:Particle size is an essential parameter in Pulverised Fuel (PF) combustion as many of the problems or further areas of development in these systems are strongly influenced by the Fuel and ash size distribution. This is particularly true for dynamic processes like pollutant formation, corrosion, erosion, slagging and fouling and the related decrease of the combustion and boiler efficiency. The evolution of particle size distribution (PSD) is a complex interaction of various competing chemical and physical transformations. Char oxidation, devolatilization and fragmentation, etc. represent first line physical and chemical transformations which can amend the particle size in the radiation zone. The evolution of the PSD represents the convolution of all of these physical and chemical transformations, operating over the entire size distribution. As a consequence, it is difficult to extract the relative importance of all competing size altering processes from the experiments. Various models such as break-up, thermal stress, shrinking core, percolation and particle-population model have been developed by incorporating numerous ash transformation mechanisms to predict the particle size evolution during the Pulverised Fuel combustion. The present work describes an adaptation of the numerical kinetic-based particle-population balance for predicting particle size evolution during PF combustion developed by Dunn-Rankin and Mitchell. The model is further simplified analytically and validated against experimental results. Several empirical parameters derived from the experiments are incorporated into the model. The resulting simplified PSD evolution model shows good agreement with literature and experimental results, with maximum 10% absolute standard deviation. Crown Copyright © 2009 Published by Elsevier Ltd. All rights reserved.
H S Mukunda - One of the best experts on this subject based on the ideXlab platform.
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part ii computational studies on a Pulverised Fuel stove
Biomass & Bioenergy, 2006Co-Authors: C Bhaskar S Dixit, P J Paul, H S MukundaAbstract:This paper presents computational and analytical studies made on the Pulverised Fuel stove reported in part I (Dixit CSB, Paul PJ, Mukunda HS. Experimental studies on a Pulverised Fuel stove. Biomass and Bioenergy, to be published). An analysis has been carried out on the condensed phase thermal profile with moving pyrolysis front for this stove. This unsteady thermal analysis that accounts for moving pyrolysis front has provided the predictions for the rate of movement of the pyrolysis front. The comparison of the predicted temperature profiles and pyrolysis front movement rates with the measured data is excellent. The single port configuration was computationally analysed with an aim to understand the aero-thermo-chemical behaviour of the stove operation in combustion and gasification modes. The g-phase of tangential entry stove was subjected to a three-dimensional analysis using a commercial CFD code CFX TASCflow with combustion modelled using single step overall reaction. It was possible to obtain combustion and gasification modes of stove operation computationally also by varying the Fuel release pattern. A Fuel release pattern biased towards the bottom of the port as seen in the experiments, when used for the calculations, resulted in gasification mode operation while uniform Fuel release pattern induced combustion mode operation. Comparison of g-phase temperature profiles in combustion mode seems satisfactory. The comparison of g-phase temperature profiles in the gasification mode appears intriguing. An explanation for the behaviour is sought in faster hydrogen combustion compared to carbon monoxide, something not accounted for in the calculations with single step chemistry.
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part i experimental studies on a Pulverised Fuel stove
Biomass & Bioenergy, 2006Co-Authors: C Bhaskar S Dixit, P J Paul, H S MukundaAbstract:This paper is concerned with development of a Pulverised Fuel stove with improved conversion efficiency and minimal emissions at near constant power level without the use of external power. The design originates from a cylindrical sawdust stove with a central porthole being lit from the bottom. Such a stove will have a flame in port with enhanced sooting tendency. For similar configuration, stable premixed combustion behaviour of the combustible gases from the port of the Fuel block (known as the gasification mode) has been achieved by use of air supply through a thin slot at the bottom, for at least 30 min of stove operation. In order to ensure stable combustion of the gases at exit, a metal device is used. In an attempt to extend gasification duration, studies are conducted in single port configuration having air entry from the bottom with a horizontal baffle to control the flow rate. This configuration worked in gasification mode for about 20 min but there have been problems of flame extinction. To overcome these drawbacks multi-port design with vertical air entry is employed with success. The stove has exhibited conversion efficiency in excess of 37% due to well focused nature of flame at exit. CO emission factors are about 12 g (kg Fuel) � 1 , a performance superior to conventional biomass stoves (� 45 g kg � 1 ). NOx emission factors are about 1 g kg � 1 Fuel which falls in the range of reported data for NOx. Studies with different Pulverised leafy Fuels have indicated these Fuels have lower volatile release rates and therefore exhibit lower power level operation for a given port configuration compared to sawdust Fuel. r 2006 Elsevier Ltd. All rights reserved.
Kalpit Shah - One of the best experts on this subject based on the ideXlab platform.
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a kinetic empirical model for particle size distribution evolution during Pulverised Fuel combustion
Fuel, 2010Co-Authors: Kalpit Shah, Christine I. Betrand, Mariusz K. Cieplik, Willem L Van De Kamp, Hari B VuthaluruAbstract:Particle size is an essential parameter in Pulverised Fuel (PF) combustion as many of the problems or further areas of development in these systems are strongly influenced by the Fuel and ash size distribution. This is particularly true for dynamic processes like pollutant formation, corrosion, erosion, slagging and fouling and the related decrease of the combustion and boiler efficiency. The evolution of particle size distribution (PSD) is a complex interaction of various competing chemical and physical transformations. Char oxidation, devolatilization and fragmentation, etc. represent first line physical and chemical transformations which can amend the particle size in the radiation zone. The evolution of the PSD represents the convolution of all of these physical and chemical transformations, operating over the entire size distribution. As a consequence, it is difficult to extract the relative importance of all competing size altering processes from the experiments. Various models such as break-up, thermal stress, shrinking core, percolation and particle-population model have been developed by incorporating numerous ash transformation mechanisms to predict the particle size evolution during the Pulverised Fuel combustion. The present work describes an adaptation of the numerical kinetic-based particle-population balance for predicting particle size evolution during PF combustion developed by Dunn-Rankin and Mitchell. The model is further simplified analytically and validated against experimental results. Several empirical parameters derived from the experiments are incorporated into the model. The resulting simplified PSD evolution model shows good agreement with literature and experimental results, with maximum 10% absolute standard deviation.
