Effect of active pulsing air flow on gas-vibro fluidized bed for fine coal separation

Dong, Liang; Zhang, Yong; Zhao, Yuemin; Peng, Liping; Zhou, Enhui; Liu, Cai; Zhang, Bo; Chen, Duan

doi:10.1016/j.apt.2016.08.012

Cited by 32 publications

(22 citation statements)

References 34 publications

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“…The most complete picture of the preparation of coal dust at thermal power plants can be obtained in the article [1]. One of the main obstacles for efficient and high-quality solid fuel combustion is its polyfractional composition, which is confirmed by the mathematical models of the authors [2]. Here the most important condition for complete combustion is the presence of a sufficient amount of air as an oxidizing agent and the fineness of grinding coal dust, as noted by the researchers [3].…”

Section: Introductionmentioning

confidence: 84%

“…It is noteworthy that the standard deviation as a generalizing argument uniquely determines function (3) and the values u = 1 and u = -1 correspond to inflection points on the curve plotted according to the dependence (3). σ 2 = (δξ) 2 /(ξ•и) 2 . Furthermore, the curve φ(u) plotted in accordance with the particle-size distribution makes it possible to easily determine the dispersion σ 2 = (δ -ξ) 2 /(ξ•и) 2 .…”

Section: Development Of Fundamental Mathematicsmentioning

confidence: 99%

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Analysis of the calculated and experimental dependencies of the combustion of coal dust on the basis of a new methodological base of theoretical studies of heat exchange processes

Toropov¹,

Осинцев²,

Aliukov³

2018

IJHT

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The methodology of theoretical studies of heat exchange processes in boiler units based on the mathematical model of burning coal dust has been developed. For the first time, the continuous curve of the fractional composition of an ensemble of coal particles is presented. The mathematical model is consistent with the aeromechanical and thermal characteristics of the torch, obtained on the basis of calculated and experimental data. The concept of a torch continuum is introduced as a continuous medium in which the processes of combustion and heat exchange are investigated. The methods of dividing the combustion chamber into zones, the equations of stationary and non-stationary heat conduction, radiation and convective heat exchange are used. These methods have been tested on a number of high-temperature installations, including boilers with natural circulation, for example, E-220 at the CHP plant in Bishkek, Kyrgyz Republic in the Central Asian region. In the course of the experiments, coals with different thermal characteristics were burned. In a special computer program obtained a 3D image of burning coal dust. Analysis of the calculated and experimental data showed a discrepancy between them of 4-5%. Analysis of computer simulation data showed a discrepancy with the calculated data of 3-4%, and with experimental 5-6%. Thus, the dependence of the parameters of the heterogeneous flame on the mathematical description of the fractional composition of coal dust is substantiated and the characteristics of the combustion process, previously not taken into account in the theory of heat transfer, are revealed. The task was solved-theoretically confirmed new methodological approaches to the theory of heat transfer in the furnace of the boiler unit.

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Section: Introductionmentioning

confidence: 84%

Section: Development Of Fundamental Mathematicsmentioning

confidence: 99%

Analysis of the calculated and experimental dependencies of the combustion of coal dust on the basis of a new methodological base of theoretical studies of heat exchange processes

Toropov¹,

Осинцев²,

Aliukov³

2018

IJHT

View full text Add to dashboard Cite

show abstract

“…It is noteworthy that the standard deviation as a generalizing argument uniquely determines function (3) and the values u = 1 and u = −1 correspond to inflection points on the curve plotted according to the dependence (3). σ 2 = (δ − ξ) 2 /(ξ•u) 2 . Furthermore, the curve ϕ(u) plotted in accordance with the particle size distribution makes it possible to easily determine the dispersion σ…”

Section: Development Of Fundamental Mathematicsmentioning

confidence: 99%

“…In [19] a solution was proposed to solve similar problems using computer simulation, and in [20,21] values u = 1 and u = −1 correspond to inflection points on the curve plotted according to the dependence (3). 2 . Furthermore, the curve φ(u) plotted in accordance with the particle size distribution makes it possible to easily determine the dispersion σ The authors calculated the correlation coefficient ry1,y2 that characterizes the tightness of the close linear connection between у1 and у2 to determine how reliable the equation of the Gaussian curve (3), plotted according to the proposed technique уcalc ≡ у2, was for the description of the practical particle size distribution of fuel dust уpr ≡ у1.…”

Section: Development Of Fundamental Mathematicsmentioning

confidence: 99%

“…Fuel combustion and heat transfer in the sections of a boiler unit (BU) are optimized and harmful emissions are minimized at the input of the BU gas path and in the combustion preparation system [1][2][3][4]. In turn, the BU arrangement and the fuel type must be adjusted to the system for preparing and supplying combustion components, the design of fuel-burning appliances (FBA), and the design of the intense combustion zone (ICZ).…”

Section: Introductionmentioning

confidence: 99%

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New Theoretical and Methodological Approaches to the Study of Heat Transfer in Coal Dust Combustion

2019

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The existing theories of heat transfer in combustion chambers of boiler units fail to take into account a number of important factors that affect the reliability of results, and the methodological approaches to optimizing combustion processes can be revised in view of the spatial and temporal parameters of flame. Hence, the research aimed to improve the fundamental theoretical and methodological principles of studying heat transfer in coal dust combustion in the combustion chambers of industrial steam generators. The authors proposed to extend the theory of heat transfer with the mathematical description of particle size distribution of coal dust. In addition, the authors used the developed mathematical model of coal dust combustion based on a continuous curve of the particle size distribution in the ensemble. The mathematical model is consistent with the aeromechanical and thermal characteristics of flame. This work introduced a concept of flame continuum as a continuous medium, where the processes of combustion and heat transfer are studied. To achieve the research aim, in this paper, the methods of combustion chamber zoning, the equations of stationary and non-stationary heat conduction, radiation, and convective heat transfer, were used. These methods were tested on a number of high-temperature units.

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Dynamics of partially collapsing pulsed fluidized bed

2021

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The use of flow pulsation as an effective assisted fluidization technique has been suggested in a number of applications, such as drying of food and pharmaceutical products, dry beneficiation of coal, and deagglomeration of nanopowders, owing mainly to its cost‐effectiveness and ease of implementation. The efficacy of this technique is, however, greatly affected by the frequency of pulsation since it controls the collapse dynamics of the fluidized bed. In this study, using ultrafine hydrophilic nanosilica with strong agglomeration tendencies, the pulsation frequency was controlled to allow only partial collapse of the bed between two successive pulsations while the global and local dynamics in different bed regions were carefully monitored. Besides the usual advantages associated with assisted fluidization techniques, such as lower minimum fluidization velocity, higher bed expansion, and elimination of bed non‐homogeneities, the continuous and intense solid motion imparted by the partial bed collapse caused a more substantial increase in the overall pressure drop than the one obtained with the conventional unassisted fluidization. The results of the frequency domain analysis highlighted the fact that the effect of pulsation event was felt differently in different regions of the bed depending upon the amplitude of the pulsation. These results were further corroborated by the similarity analysis.

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Effect of active pulsing air flow on gas-vibro fluidized bed for fine coal separation

Cited by 32 publications

References 34 publications

Analysis of the calculated and experimental dependencies of the combustion of coal dust on the basis of a new methodological base of theoretical studies of heat exchange processes

Analysis of the calculated and experimental dependencies of the combustion of coal dust on the basis of a new methodological base of theoretical studies of heat exchange processes

New Theoretical and Methodological Approaches to the Study of Heat Transfer in Coal Dust Combustion

Dynamics of partially collapsing pulsed fluidized bed

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