Heat-transfer from horizontal tube bundles into fluidized beds with Geldart A lignite particles

Lechner, Stefan; Merzsch, Matthias; Krautz, Hans Joachim

doi:10.1016/j.powtec.2013.10.041

Cited by 31 publications

(15 citation statements)

References 12 publications

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“…Lechner et al investigated the heat transfer between the fluidized Geldart A lignite particles and horizontal heat tube bundles. The effects of tube diameter, particle diameter, and the arrangement of tube bundles on heat‐transfer coefficients were measured and correlated with heat‐transfer coefficient.…”

Section: Introductionmentioning

confidence: 99%

Systematic study on heat transfer and surface hydrodynamics of a vertical heat tube in a fluidized bed of FCC particles

Yao

Zhang

et al. 2014

AIChE Journal

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Bed-to-wall heat transfer properties of a vertical heat tube in a fluidized bed of fine fluid catalytic cracking (FCC) particles are measured systematically using a specially designed heat tube. Two important surface hydrodynamic parameters, i.e. the packet fraction (d pa ) and mean packet residence time (s pa ) based on the packet renewal theory, are determined by an optical fiber probe and a data processing method. The experimental results successfully reveal the axial and radial profiles of heat-transfer coefficient, the effects of superficial gas velocity, and static bed height on heat-transfer coefficient, most of which can be explained successfully by the measured s pa , an indicator of packet renewal frequency. s pa is found to play a more dominant role than d pa on bed-to-wall heat transfer. With a fitted correction factor, the modified Mickley and Fairbanks model is able to predict the heat-transfer coefficients with enough accuracy based on the determined packet parameters. Figure 23. Effect of static bed height on heat-transfer coefficients.

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Section: Introductionmentioning

confidence: 99%

Systematic study on heat transfer and surface hydrodynamics of a vertical heat tube in a fluidized bed of FCC particles

Yao

Zhang

et al. 2014

AIChE Journal

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“…Tube bundle factor Lechner et al [25] (Geldart type B) (11) Furthermore, a heat exchanger tube diameter factor model proposed by Petrie et al [11] can be multiplied to the model by Molerus et al [21,22] to consider the impact of tube diameters. Lechner et al [25] developed a tube bundle reduction factor for comparison theoretical and experimental heat transfer coefficients. Furthermore, a factor model which considers Geldart type B is introduced by Lechner et al [25], that can be applied to the model by Molerus et al [21,22] and Natusch et al [23].…”

Section: Modelmentioning

confidence: 99%

“…Lechner et al [25] developed a tube bundle reduction factor for comparison theoretical and experimental heat transfer coefficients. Furthermore, a factor model which considers Geldart type B is introduced by Lechner et al [25], that can be applied to the model by Molerus et al [21,22] and Natusch et al [23].…”

Section: Modelmentioning

confidence: 99%

“…To consider tube bundle configurations for heat exchanger design, some models are designed to calculate tube bundle reduction factors [11,25], which can be multiplied to the single tube models. According to Hofer et al [26], the particle diameter, tube diameter and tube bundle spacing have a significant influence on the heat transfer rates and furthermore, the models by Natusch et al [23] and Molerus et al [21,22] lead to qualitative and quantitative differences compared to the obtained results.…”

Section: Introductionmentioning

confidence: 99%

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Experimental and Numerical Investigations on Heat Transfer of Bare Tubes in a Bubbling Fluidized Bed with Respect to Better Heat Integration in Temperature Swing Adsorption Systems

2019

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In this paper experimental and numerical investigations on heat transfer within a bubbling fluidized bed will be presented with respect to better heat integration in continuous temperature swing adsorption (TSA) processes for biogas upgrading. In the literature, mainly heat transfer measurements with glass or sand particles are carried out, thus special reference measurements with adsorbent material in a fluidized bed are missing. Therefore firstly, a series of experiments were carried out in the fluidized bed test facility to obtain heat transfer coefficients between tube surface and bed which were then compared to calculated heat transfer coefficients to determine whether suitable models were available. Horizontal bare tubes with different arrangements (i.e., single tubes and especially tube bundles) are immersed in fluidized amine layered particles with a mean diameter of 650 μ m which are used in the adsorption industry as adsorbent. The test facility enables a cross-current flow of the solids and gas phase as it prevails in a multi-stage fluidized bed reactor for TSA-applications. The heat transfer measurements with different arrangements and adsorbent material show very similar values in the range of 200 W/m 2 K. The mathematical model for single tubes multiplied by a tube diameter factor shows approximate agreement with the experimental results. However, the mathematical models for tube bundles were not able to predict the measured heat transfer coefficients with the required accuracy. Secondly, a computer fluid dynamics (CFD) program was used to perform a numerical investigation of the test facility using the Euler–Euler method in order to describe the required two-phase characteristic of a fluidized bed. The results of the numerical simulation were compared and validated with the experimental results. Bubbling fluidized bed flow regimes could be reproduced well but the heat transfer coefficients between tube and bed were clearly underestimated. However, a numerical study for a bubbling fluidized bed with external circulation, as used in novel continuous TSA systems, could be carried out and thus a tool for better heat integration measures was developed.

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“…The bed was silica sand particles with diameter (200, 350 and 500) μm, the result showed increased heat transfer coefficient with increased air superficial velocity, and decreased by increased particle diameter. S. Lechner et al [18] examines the heat transfer by fluidized beds when used a cylindrical heater, for just one and also when used many of them, also study changing fluidize bed material effect on heat transfer. The bed area was 0.15m2, used (lignite) as a solid particle.…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Study the Effect of Solid Particles Flow on Heat Pipe Performance

Al-Ghazali¹,

Aljibory²,

Alkharasani³

et al. 2018

IJET

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A numerical work supported by experimental results was carried out to studying of passing a hot solid particle on heat pipe performance. used Ansys fluent 18.0 as a computer program, geometry was published using design modular engaged in it. 3Dimention model with the steady state was studied to knowing the temperature distributed inside the evaporator and condenser part domain, more clearly to particle behavior and streamline 2Dimention model with transient was studied also. Depended on particle of 105µm diameter and experimental measuring properties set with height range (2.5 to 5) cm inside evaporator part from box, velocity with range (0.8739 to 1.377) m/s was take in consideration, the result shown enhancement in Nusselt number by (58) % when the velocity 1.377 m/s and particle bed height 5 cm compared with the first state, pressure drop with acceptable range was measured not exceed (42) %

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Heat-transfer from horizontal tube bundles into fluidized beds with Geldart A lignite particles

Cited by 31 publications

References 12 publications

Systematic study on heat transfer and surface hydrodynamics of a vertical heat tube in a fluidized bed of FCC particles

Systematic study on heat transfer and surface hydrodynamics of a vertical heat tube in a fluidized bed of FCC particles

Experimental and Numerical Investigations on Heat Transfer of Bare Tubes in a Bubbling Fluidized Bed with Respect to Better Heat Integration in Temperature Swing Adsorption Systems

Numerical and Experimental Study the Effect of Solid Particles Flow on Heat Pipe Performance

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