Experimental study on ignition behavior of pulverized coal particle clouds in a turbulent jet

Xu, Ke; Wu, Yuxin; Wang, Zhennan; Yang, Yanmei; Zhang, Hai

doi:10.1016/j.fuel.2015.11.027

Cited by 32 publications

(27 citation statements)

References 22 publications

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“…However, in a turbulent coal particle cloud, the flame propagation velocity is not much different for the various coal concentrations at a given turbulence intensity. According to Xu et al [20], in the pulverized coal particle turbulent jet flame, eddies in the particle-loading turbulent jet strongly affect the ignition process, shortening the ignition delay time. However, there was no obvious effect of coal concentration on the ignition distance [20].…”

Section: Flame Propagation Velocitymentioning

confidence: 99%

Spherical turbulent flame propagation of pulverized coal particle clouds in an O2/N2 atmosphere

Hadi

Ichimura

Hashimoto

et al. 2019

Proceedings of the Combustion Institute

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This study aimed to clarify the effects of turbulence intensity and coal concentration on the spherical turbulent flame propagation of a pulverized coal particle cloud. A unique experimental apparatus was developed in which coal particles can be dispersed homogeneously in a turbulent flow field generated by two fans. Experiments of spherical turbulent flame propagation of pulverized coal particle clouds in a constant volume spherical chamber in various turbulence intensities and coal concentrations were conducted using the new experimental apparatus. A common bituminous coal was used in this study.Flame propagation velocity was obtained based on the analysis of flame propagation images taken using a high-speed camera. It was found that the flame propagation velocity increased with increasing flame radius. For various turbulence intensities, the flame propagation velocity increases as the turbulence intensity increases. Similar trends were observed in spherical flames using gaseous fuel.The coal concentration has a weak effect on the flame propagation velocity, which is a feature that is unique to pulverized coal flames in a turbulent field. Experimental results of a spherical flame propagation behavior of turbulent pulverized coal particle cloud have been reported for the first time.The results obtained in this study are obviously different from previous pulverized coal combustion studies and any other results of gaseous fuel combustion research.

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Section: Flame Propagation Velocitymentioning

confidence: 99%

Spherical turbulent flame propagation of pulverized coal particle clouds in an O2/N2 atmosphere

Hadi

Ichimura

Hashimoto

et al. 2019

Proceedings of the Combustion Institute

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show abstract

“…The ignition points located exactly where the continuous flame zones started as showed in Figure . The measured ignition distance was around 0.06 m referring to Xu et al When the initial particle sizes were determined by the quadrature‐based method, the ignition distances were poorly predicted with one QN which only resolved the first‐order moment. However, coal particles with a diameter of D 32 could successfully capture the ignition distance.…”

Section: Resultsmentioning

confidence: 99%

“…The high‐temperature zones formed around the central jet act as heat sources, which can help to decrease the ignition delay. As for high‐volatile coal, the ignition of coal cloud is mainly regarded as a homogeneous process . Therefore, the ignition behaviors of coal cloud are combined results of particle dispersion, heat transfer, and devolatilization processes, which correspond to momentum, energy, and mass exchanges between gas and discrete phases, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…The representative particle streams defined by the quadrature‐based method were set as the initial conditions in the LES simulations which were conducted for the pulverized coal jet flame in a Hencken‐type entrained‐flow reactor. The experiments were carried out by Xu and his co‐workers . One set of operating conditions was chosen for the simulations.…”

Section: Model Validationmentioning

confidence: 99%

“…Based on the theoretical analysis of coal combustion, D 32 was chosen as the only QN in S6 in consideration of the mass and energy exchange processes. The kinetic parameters of devolatilization and char combustion processes were optimized by comparing the predicted ignition distances with the experimental data under different operating conditions . All the simulation cases in this study adopted the same kinetic parameters.…”

Section: Model Validationmentioning

confidence: 99%

See 2 more Smart Citations

Identification of the initial particle size distribution for coal combustion simulations

Shen

Zhou

et al. 2019

AIChE Journal

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Pulverized coal generally features wide particle-size distributions (PSD). How to set an initial PSD in coal combustion simulation remains an open question. To answer this, the Gaussian-quadrature theory was applied to provide a discrete reconstruction of the PSD described by Rosin-Rammler and Upper-Limit functions. From the perspective of the moments of PSD, a theoretical analysis was conducted for mass, momentum, and energy exchange terms between gas and particle phases in pulverized coal jet flame. The analysis presented that the first, the second and the third moments of PSD were the most important to capture the flame ignition behavior. The large eddy simulations showed that the proposed method with two or more particle sizes could provide good predictions of flame ignition distances. And Sauter mean diameter (D 32 ) could represent the complete PSD when predicting the ignition behavior of pulverized coal jet flame. K E Y W O R D Scoal combustion, Gaussian quadrature, initial particle size distribution, large eddy simulation, moments

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Ignition Characteristics of Coal/Air Jets from Rectangular Nozzles

Liu

Yang

et al. 2021

Clean Coal and Sustainable Energy

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Experimental study on ignition behavior of pulverized coal particle clouds in a turbulent jet

Cited by 32 publications

References 22 publications

Spherical turbulent flame propagation of pulverized coal particle clouds in an O2/N2 atmosphere

Spherical turbulent flame propagation of pulverized coal particle clouds in an O2/N2 atmosphere

Identification of the initial particle size distribution for coal combustion simulations

Ignition Characteristics of Coal/Air Jets from Rectangular Nozzles

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