Simulation of Effective Thermal Conductivity of Metal Hydride Packed Beds

The upper and lower bounds of the effective thermal conductivity of packed beds of rough spheres are evaluated using the theoretical approach of the elementary cell for two-phase systems. The solid mechanics and thermal problems are solved and the effects of roughness and packed bed structures are also examined. The numerical solution of the thermal conduction problem through the periodic regular arrangement of steel spheroids in air is determined using the Finite Element Method. The numerical results are compared with those obtained from an experimental apparatus designed and built for this purpose.

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Numerical analysis of effective thermal conductivity with thermal conduction and radiation in packed beds

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2017.06.083 ◽

2017 ◽

Vol 114 ◽

pp. 402-406 ◽

Cited By ~ 6

Author(s):

Yusuke Asakuma ◽

Itsuro Honda ◽

Tsuyoshi Yamamoto

Keyword(s):

Thermal Conductivity ◽

Numerical Analysis ◽

Effective Thermal Conductivity ◽

Thermal Conduction ◽

Packed Beds

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Influence of Contact Mechanics in the Prediction of the Effective Thermal Conductivity of Spheroid Packed Beds

Heat Transfer: Volume 1 ◽

10.1115/ht2003-47351 ◽

2003 ◽

Cited By ~ 1

Author(s):

G. Buonanno ◽

A. Carotenuto ◽

G. Giovinco ◽

L. Vanoli

Keyword(s):

Thermal Conductivity ◽

Effective Thermal Conductivity ◽

Statistical Approach ◽

Thermal Contact ◽

Peak Height ◽

Thermal Contact Conductance ◽

Curvature Radius ◽

Packed Beds ◽

Wide Range ◽

Thermal Phenomena

Thermal contact conductance is an important parameter in a wide range of thermal phenomena, and consequently a large number of experimental, numerical and statistical investigations have been carried out in literature. In the present paper an analysis of thermal contact resistance is carried out to predict heat transfer between spherical rough surfaces in contact, by means of a statistical approach. The micro-geometry of the surface is described through a probabilistic model based on the peak height variability and invariant asperity curvature radius. The numerical model has been applied to evaluate the effective thermal conductivity of packed beds of steel spheroids and validated through the comparison with the experimental data obtained by means of an apparatus designed and build up for this purpose.

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Numerical Simulation of Heat and Mass Transfer in Metal Hydride Hydrogen Accumulators of Different Complex Designs

2010 14th International Heat Transfer Conference, Volume 6 ◽

10.1115/ihtc14-22561 ◽

2010 ◽

Author(s):

Dmitriy Lazarev ◽

Valeriy Artemov ◽

Georgiy Yankov ◽

Konstantin Minko

Keyword(s):

Thermal Conductivity ◽

Mass Transfer ◽

Effective Thermal Conductivity ◽

Heat And Mass Transfer ◽

Metal Hydride ◽

Solid Phase ◽

Three Dimensional ◽

Calculated Data ◽

Sorption Rate ◽

Gas Admixtures

A three-dimensional mathematical model of unsteady heat and mass transfer in porous hydrogen-absorbing media, accounting for presence of “passive” gas admixtures, is developed. New technique for evaluation of effective thermal conductivity of porous medium, which consists of microparticles, is suggested. Effect of “passive” gas admixtures on heat and mass transfer and sorption rate in metal hydride reactor is analyzed. It is shown that decrease of effective thermal conductivity and partial hydrogen pressure under decrease of hydrogen concentration effect on the hydrogen sorption rate considerably. It is disclosed that an intensive 3D natural convection takes place in a gas volume of reactor under certain conditions. Numerical analysis of heat and mass transfer in metal-hydride reactor of hydrogen accumulation systems was done. Sorption of hydrogen in cylindrical reactors with external cooling and central supply of hydrogen are analyzed including reactors with finned active volume and tube-shell reactor with external and internal cooling cartridge matrix. Unsteady three dimensional temperature and concentration fields in solid phase are presented. Integral curves representing the dynamic of sorption and desorption are calculated. Data on efficiency of considered reactors are presented and compared.

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