Multidimensional thermal structures in the singularly perturbed stationary models of heat and mass transfer with a nonlinear coefficient of thermal conductivity

2021 ◽  
pp. 113731
Author(s):  
M.A. Davydova ◽  
S.A. Zakharova
Keyword(s):  
Thermal Conductivity ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Nonlinear Coefficient ◽  
Singularly Perturbed ◽  
Thermal Structures ◽  
Coefficient Of Thermal Conductivity

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

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.

Permeability and Thermal Conductivity of Compact Adsorbent of Salts for Sorption Refrigeration

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
L. Jiang ◽  
L. W. Wang ◽  
Z. Q. Jin ◽  
B. Tian ◽  
R. Z. Wang
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Transfer Performance ◽  
Natural Graphite ◽  
Heat Transfer Intensification

Properties, such as thermal conductivity and permeability, are important for the heat and mass transfer performance in sorption refrigeration. This Technical Brief investigates the thermal conductivity and permeability of eight types of chlorides, which are consolidated with expanded natural graphite (ENG) for the heat transfer intensification.

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