Green’s function solution for transient heat conduction in annular fin during solidification of phase change material

2012 ◽  
Vol 33 (10) ◽  
pp. 1265-1274 ◽  
Author(s):  
A. H. Mosaffa ◽  
F. Talati ◽  
M. A. Rosen ◽  
H. Basirat-Tabrizi
Keyword(s):  
Heat Conduction ◽  
Phase Change ◽  
Green’S Function ◽  
Phase Change Material ◽  
Green's Function ◽  
Transient Heat Conduction ◽  
Function Solution ◽  
Annular Fin ◽  
Change Material

Reducing Heat Conduction of Autoclaved Aerated Concrete Wall Using Phase Change Material

2013 ◽  
Vol 807-809 ◽  
pp. 2779-2783
Author(s):  
Atthakorn Thongtha ◽  
Somchai Maneewan ◽  
Chantana Punlek ◽  
Yothin Ungkoon
Keyword(s):  
Heat Conduction ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Source ◽  
Concrete Wall ◽  
Autoclaved Aerated Concrete ◽  
Thermal Delay ◽  
Aerated Concrete ◽  
Change Material ◽  
Minimum Heat

In this work, the effect of the salt hydrated phase change material (PCM) on microstructure and heat conduction of the autoclaved aerated concrete (AAC) was studied. The microstructure in the AAC and AAC with composed phase change material was imaged by scanning electron microscopy (SEM). The ability in heat conduction was compared among AAC (AAC1), AAC with composed phase change material (0.417 (AAC2) and 0.833 (AAC3) kg/m2 in contents), and AAC which was composed by PCM (0.417 (AAC4) and 0.833 (AAC5) kg/m2 in contents) and was coated by the cement in 2 sides. These ones were tested the thermal delay at 40, 50 and 60 °C using the heater that was the thermal source. It was found that the optimum content of PCM on top surface was found at 0.417 kg/m2 because the minimum heat conduction and the lowest average temperatures of inside wall and inside room were shown in this sample at 40, 50 and 60 °C.

Study on the heat conduction of phase-change material microcapsules

2013 ◽  
Vol 22 (3) ◽  
pp. 257-260 ◽  
Author(s):  
Gangtao Zhao ◽  
Xiaohui Xu ◽  
Lin Qiu ◽  
Xinghua Zheng ◽  
Dawei Tang
Keyword(s):  
Heat Conduction ◽  
Phase Change ◽  
Phase Change Material ◽  
Change Material

Green’s Function Solution of Dual-Phase-Lag Model

2009 ◽  
Author(s):  
Yung-Ming Lee ◽  
Pei-Chi Lin ◽  
Tsung-Wen Tsai
Keyword(s):  
Heat Conduction ◽  
Heat Source ◽  
Green’S Function ◽  
Green's Function ◽  
Phase Lag ◽  
Micro Scale ◽  
Function Solution ◽  
Lag Model ◽  
Temperature Solution ◽  
Good Agreement

In this study, the micro-scale heat conduction solution in a finite rigid slab computed with and without heat source is investigated. The analytical solution is derived by Laplace transform (LT) technique and Green’s function solution (GFS) method. The effect of heat source on the micro-scale heat conduction solution is also included in this paper. It is found that the temperature solution obtained by GFS method is smaller than that obtained by LT technique, and the GFS is in very good agreement with the solution obtained by the conventional Fourier’s law when τq = τT. Moreover, the temperature distributions computed by the LT technique are always overestimated in this study owing to the absence of the G2 effect. Hence, it is believed that the temperature solutions predicted by the GFS-LT method are more accurate than those evaluated by the LT technique. When time is increasing, the discrepancies of temperature solutions among various methods for τT > τq is increasing.

Temperature Moderation in a Real-Size Room by PCM-Based Units

2005 ◽  
Vol 128 (2) ◽  
pp. 178-188 ◽  
Author(s):  
S. Mozhevelov ◽  
G. Ziskind ◽  
R. Letan
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Forced Convection ◽  
Radiation Effects ◽  
Phase Change Materials ◽  
Transient Heat Conduction ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Real Size ◽  
Change Material

The objective of this work is to study the feasibility of temperature moderation inside a room using a phase-change material (PCM) which is stored in storage units. A real-size room which is at temperature conditions typical in a desert region in summer is considered. The idea is to use a phase change material which could melt during the day hours, absorbing heat from the room, while at night it solidifies due to a low night temperature. The heat from the room air to a PCM unit is free or forced-convected. The numerical model includes the transient heat conduction inside the walls/ceiling, free/forced convection of air, and radiation inside the room. The processes inside the PCM are modeled by the effective heat capacity (EHC) method. The PCM is assumed to melt and solidify within a certain temperature range, which represents the true situation for most commercial-grade phase-change materials. The numerical calculations are performed for the transient temperature fields inside the three-dimensional room, including PCM in the units, walls/ceiling, and the interior of the room. The boundary conditions for the room are chosen according to the experimental data which were obtained in previous works. The basic conservation equations of continuity, momentum, and energy are solved numerically, using the FLUENT 6.1 software. The numerical simulations are performed for at least one full 24-hcycle. Effect of different parameters on the behavior of the system is discussed, including the mass of the PCM and radiation effects inside the room. The night cooling by free and forced convection is analyzed. It is shown that a complete 24-hcycle is feasible in a properly designed configuration with a suitable PCM.

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