Estimating Correlation of Effective Thermal Conductivity on the Spherical Packed Bed Porous Media

2014 ◽  
Vol 575 ◽  
pp. 282-286
Author(s):  
Rapeepong Peamsuwan ◽  
Bundit Krittacom
Keyword(s):  
Thermal Conductivity ◽  
Porous Media ◽  
Effective Thermal Conductivity ◽  
Electrical Power ◽  
Average Diameter ◽  
Packed Bed ◽  
Water Cooling ◽  
Experimental Procedure ◽  
Higher Temperature ◽  
Lower Temperature

The correlation of an effective thermal conductivity (keff) on spherical packed bed porous media with stagnant fluid was proposed. Alumina-Cordierite ceramic ball (Al-Co) having average diameter (d) of 2.1 cm and porosity (Φ) of 0.468 was examined. The experimental procedure was operated based on ASTM E1225. The tested porous sample was sandwiched by references materials (Solid Brass, 70%Cu, 30%Zn). A higher temperature (TH) on the top of test set was obtained from wire heater with a constant electrical power of 350 W. The water cooling set was installed at the bottom of to generate a lower temperature (TL). Four previous models established from geometrical structure were compared to validate the present correlation. From experiment, it was found that keff decreased with increasing TH. Thus, the relation between keff and TH was appropriately proposed by a correlating linear-equation (keff/kf = 329.2(1-0.1028(TH/100)). Agreement between the present correlation and literature models was satisfied particular.

The Effective Thermal Conductivity (ETC) of Spherical Packed-Bed Porous Media for Modification of the Color Surface as Black Color

2018 ◽  
Vol 911 ◽  
pp. 100-104
Author(s):  
Bundit Krittacom ◽  
Pornsawan Tongbai
Keyword(s):  
Thermal Conductivity ◽  
Porous Media ◽  
Effective Thermal Conductivity ◽  
Average Diameter ◽  
Packed Bed ◽  
Worst Case ◽  
Original Surface ◽  
Black Surface ◽  
Black Color ◽  
Stagnant Fluid

The effective thermal conductivity (ETC) of the spherical packed-bed porous media in stagnant fluid case is estimated by modifying the color surface of the porous media as black surface. The Alumina-Cordierite (Al-Co) ceramic balls having average diameter (d) of 5.0 cm is constructed as the porous media and, then, a porosity (f) has 0.398. For development of the porous media as black surface, the Al-Co ceramic balls are painted by black color and then it is composed of 600 °C × 8 hr. The experimental procedure to evaluate the ECT is based on ASTM E1225. A higher temperature (TH) is investigated in the range of 400 to 800 K at the constant power of 350 W. The ETC of three surfaces of the Al-Co ceramics ball, i.e., original surface (λorg), combined black-painted and original surface (λcom) and black surface (λblk), are examined. From experiment, it is found that all ETC of three surfaces decrease with increasing TH. The value of three ETCs are in the range of 6.2 to 27.1 W/(m K). The lblk gives highest for the present research and, exactly, the worst case is obtained by λorg. Thus, the ETC of spherical packed-bed porous media with stagnant fluid can be improved by developing the color surface as black color.

scholarly journals The effect of particle shape on the packed bed effective thermal conductivity based on DEM with polyhedral particles on the GPU

2020 ◽  
Vol 219 ◽  
pp. 115584 ◽  
Author(s):  
Nicolin Govender ◽  
Paul W. Cleary ◽  
Mehran Kiani-Oshtorjani ◽  
Daniel N. Wilke ◽  
Chuan-Yu Wu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Particle Shape ◽  
Packed Bed ◽  
Polyhedral Particles

scholarly journals Measurement of Thermal Conductivity along the Radial Direction in a Vertical Cylindrical Packed Bed

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Swaren Bedarkar ◽  
Nurni Neelakantan Viswanathan ◽  
Nidambur Bharatha Ballal
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Crucial Role ◽  
Iron Ore ◽  
Radial Direction ◽  
Thermal Response ◽  
Packed Bed ◽  
Lumped Parameter ◽  
Scientists And Engineers

Heat transfer in packed beds and their thermal response have been of great interest for scientists and engineers for the last several years, since they play a crucial role in determining design and operation of reactors. Heat transfer of a packed bed is characterised through lumped parameter, namely, effective thermal conductivity. In the present studies, experiments were performed to investigate the thermal conductivity of a packed bed in radial direction. The packed bed was formed using iron ore particles. To determine the effective thermal conductivity a new transient methodology is proposed. The results obtained were compared with the models proposed by ZBS and Kunii and Smith.

Experimental and Theoretical Modeling of the Effective Thermal Conductivity of Rough Steel Spheroid Packed Beds

2003 ◽  
Vol 125 (4) ◽  
pp. 693-702 ◽  
Author(s):  
G. Buonanno ◽  
A. Carotenuto ◽  
G. Giovinco ◽  
N. Massarotti
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Solid Mechanics ◽  
Packed Bed ◽  
Elementary Cell ◽  
Upper And Lower Bounds ◽  
Packed Beds ◽  
The Finite Element Method ◽  
Two Phase ◽  
Experimental Apparatus

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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