Modeling of Pulverized Coal Combustion in Turbulent Flow with the Consideration of Intermediate Reactions of Volatile Matter

Cui, Kai; Liu, Bing; Zhang, Hai; Wu, Yuxin; Matsumoto, Keigo; Takeno, Keiji

doi:10.1021/ef3017514

Cited by 11 publications

(5 citation statements)

References 36 publications

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“…Therefore, it was noticed that the lower value of residence time affected the flame temperature and caused higher flame temperature to reach the value of about 1950 𝐾. Hence, higher combustion rates and flame temperature were observed at lower turbulent mixing time scale of fuel and oxidizer species as described in [23][24][25][26][27]. It is realized that fuel-oxidizer mixing problems in burners are linked to the mechanics of aerodynamics.…”

Section: Discussionmentioning

confidence: 99%

Combustion modeling of bituminous coal using turbulence- chemistry interactions for sustainable fuel

Qureshi,

Manzoor,

Naseem

et al. 2024

Preprint

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Studies in the computational fluid dynamics (CFD) context have made it possible in short duration, to deliver the insights into complex combustion processes involved in solid fuel combustion such as, pyrolysis /evaporation, de-volatilization, char combustion as well energy exchange between gases, particles, and burner walls. In this work, computational investigation has been performed on a fluid dynamically stabilized pilot-scale oxy-coal burner at standard thermodynamic conditions. Turbulent combustion modeling was carried out with turbulence chemistry interaction model using Finite Rate / Eddy Dissipation model along with other sub-models. More specifically, the concept of CO2 recirculating oxy-fuel combustion technology is utilized to achieve the stable flame and air-coal combustion like flame parameter especially the flame temperature. The radial profiles of combustion parameters were observed at radial lines located at different axial distances downstream of combustor inlet. Effects of varying turbulent mixing time scale or mean residence time is studied owing to its importance in optimizing fuel-oxidizer mixing and sub-sequent combustion process. It is observed that stable flame in air like oxy-coal combustion is achieved, and flame temperature of 1850 K have been noticed. Lower turbulent mixing scale or residence time caused higher flame temperature of 1950 K. CO2 recirculating oxy-coal combustion process can be optimized by aerodynamic control strategies for efficient mixing while keeping the NOx emissions in control. Because of N2 replacement with CO2 in the oxy-fuel combustion environment, the dissociation of N2 species even at higher temperature can be avoided.

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Section: Discussionmentioning

confidence: 99%

Combustion modeling of bituminous coal using turbulence- chemistry interactions for sustainable fuel

Qureshi,

Manzoor,

Naseem

et al. 2024

Preprint

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“…Multi-step detailed chemical kinetic can be introduced in this approach. However finite rate model and Eddy dissipation model combination (FR/ED) are also used 86 to predict gas-phase combustion. The minimum rate out of two is considered as the reaction rate for chemistry calculation.…”

Section: Gas-phase Combustion Modelingmentioning

confidence: 99%

“…So many researchers used ED and EDU 70,90,91 for PCC gas-phase combustion modeling. Cui et al 86 made an intensive comparative study of gas-phase combustion model performance for the pulverized coal combustion process. EBU, ED, ED/FR, ED-cp, MF-PDF, EDC-G, EDC-R. where ED-cp means Eddy dissipation model with modified cp.…”

Section: Gas-phase Combustion Modelingmentioning

confidence: 99%

Pulverized coal combustion computational modeling approach: A review

Ghose

Sahoo

Sahu

2022

Proceedings of the Institution of Mechanical Engineers, Part A:

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CFD (Computational fluid dynamics) is a tool, through which, the entire combustion process for pulverized coal combustion (PCC) can be predicted. The solid fuel combustion modeling is not as simple as gaseous or liquid fuel combustion modeling. In the solid fuel combustion process, various physical transformations and chemical reactions occur simultaneously. Therefore in the computational modeling approach for PCC, basic physical and chemical processes such as; turbulence, radiation, devolatilization, gas-phase combustion, char reaction and soot formation/reduction are integrated to obtain the desired results. However, in order to reach the desired accuracy, different computational models should be chosen carefully. In this review, various common models that are widely used in PCC simulation are discussed scientifically along with their modeling aspects. The basic advantages and disadvantages of these models are also discussed in this study. Moreover, different models preferred by various authors for pulverized coal combustion simulation process are also summarized. From the review, it has been observed that the eddy viscosity based two-equation turbulent models and Eulerian-Lagrangian multiphase approach are mostly preferred due to better computational economy. Two competing rate devolatilization model from various finite rate models and FG-DVC devolatilization model from various phenomenological models are mostly used for PCC. Diffusion kinetic control and Intrinsic char combustion models are mostly chosen to predict the char reaction. Finite reaction rate models are preferred when the computational economy is a concern, whereas phenomenological models provide results with better accuracy because in phenomenological models realistic inputs are given as input for simulation whereas, in finite rate models, finite rate constants are mostly empirical. Most of the gas phase models are given almost equal importance. Discrete ordinate (DO) is mostly used for PCC due to its ability of volumetric radiation calculation and the ability to evaluate radiation effect on the particle phase.

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“…where m v (t) is the overall amount of volatiles in the fuel particle at time t after the devolatilization process (kg), TABLE 4 Governing conservation equations 21,43 Continuous Phase…”

Section: Model Description and Assumptionsmentioning

confidence: 99%

Development of a high‐temperature two‐stage entrained flow gasifier model for the process of biomass gasification and syngas formation

2019

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Summary This paper presents development of the Mitsubishi Heavy Industries (MHI) gasifier utilizing an analogy between a model with coal feedstock and the model with torrefied woody biomass. A computational fluid dynamics (CFD) model was primarily developed for coal gasification, and the simulation results were validated with similar published work and experimental measurements. The model was extended for the woody biomass to predict the gasifier performance under the gasification process. The results were used to compare the effect of fuel type on the gasifier performance and gaseous product compositions. The second‐level injection nozzles were modified tangentially, and the flow characteristics, species yields, and temperature were evaluated. The possibility of reducing the gasifier length from 13 to 8 m is also evaluated for different total length. The results revealed that using woody biomass leads to a decrease in the mole fraction of CO and H2 at the gasifier outlet compared with coal. An opposite trend was observed for CO2 and CH4 compositions. The contributions of modified second‐level nozzles to the total gas composition and exit temperature only account for less than 3%. Reducing the gasifier length from 13 to 8 m increased the exit temperature from 1289 to 1340 K, but the changes in the exit gas composition were less than 2%. The new design of the MHI gasifier can reduce the investment costs by reducing the gasifier length as well as using biomass instead of coal.

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Modeling of Pulverized Coal Combustion in Turbulent Flow with the Consideration of Intermediate Reactions of Volatile Matter

Cited by 11 publications

References 36 publications

Combustion modeling of bituminous coal using turbulence- chemistry interactions for sustainable fuel

Combustion modeling of bituminous coal using turbulence- chemistry interactions for sustainable fuel

Pulverized coal combustion computational modeling approach: A review

Development of a high‐temperature two‐stage entrained flow gasifier model for the process of biomass gasification and syngas formation

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