scholarly journals Experimental analysis of the effective thermal conductivity enhancement of PCM using finned tubes in high temperature bulk tanks

2018 ◽  
Vol 142 ◽  
pp. 736-744 ◽  
Author(s):  
Antoni Gil ◽  
Gerard Peiró ◽  
Eduard Oró ◽  
Luisa F. Cabeza
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Effective Thermal Conductivity ◽  
Experimental Analysis ◽  
Thermal Conductivity Enhancement ◽  
Conductivity Enhancement ◽  
Finned Tubes

Estimation and optimisation of effective thermal conductivity for polymer matrix composites with hybrid inclusions

2017 ◽  
Vol 52 (16) ◽  
pp. 2139-2148 ◽  
Author(s):  
MU Siddiqui ◽  
Abul Fazal M Arif
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Polymer Matrix Composites ◽  
Effective Medium Theory ◽  
Thermal Conductivity Enhancement ◽  
Single Type ◽  
Model Parameters ◽  
Matrix Composites ◽  
Optimum Ratio ◽  
Conductivity Enhancement

Composites with hybrid inclusions have shown remarkable thermal conductivity enhancement over composites with a single type of inclusion. However, to achieve maximum thermal conductivity enhancement, the optimum ratio of inclusions in the hybrid mix needs to be determined. In this communication, an effective medium theory based model for the estimation of effective thermal conductivity of composites with hybrid inclusions is presented. The proposed model accurately captures the synergic effect of hybrid inclusions within the composite and can be used to optimise the filler ratio in the hybrid mix. The model has been validated against several published experimental results and is found to be in good agreement with them. Parametric studies have also been carried out to study the effect of material and model parameters on the optimum ratio of hybrid inclusions.

scholarly journals Enhanced Thermal Conductivity of Water With Surfactant Encapsulated and Individualized Single-Walled Carbon Nanotube Dispersions

2012 ◽  
Author(s):  
S. Harish ◽  
Kei Ishikawa ◽  
Erik Einarsson ◽  
Taiki Inoue ◽  
Shohei Chiashi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotube ◽  
Effective Thermal Conductivity ◽  
Volume Fraction ◽  
Thermal Conductivity Enhancement ◽  
Optical Absorption Spectroscopy ◽  
Single Walled Carbon Nanotube ◽  
Conductivity Enhancement ◽  
Single Walled Carbon ◽  
Higher Temperature

In the present work, the effective thermal conductivity of single walled carbon nanotube dispersions in water was investigated experimentally. Single-walled carbon nanotubes (SWNTs) were synthesized using the alcohol catalytic chemical vapour deposition method. The diameter distribution of the SWNTs was determined using resonance Raman spectroscopy. Sodium deoxycholate (SDC) was used as the surfactant to prepare the nanofluid dispersions. Photoluminescence excitation spectroscopy (PLE) reveals that majority of the nanotubes were highly individualized when SDC was employed as the surfactant. The nanofluid dispersions were further characterized using transmission electron microscopy, atomic force microscopy (AFM) and optical absorption spectroscopy (OAS). Thermal conductivity measurements were carried out using a transient hot wire technique. Nanotube loading of up to 0.3 vol% was used. Thermal conductivity enhancement was found to be dependent on nanotube volume fraction and temperature. At room temperature the thermal conductivity enhancement was found to be non-linear and a maximum enhancement of 13.8% was measured at 0.3 vol% loading. Effective thermal conductivity was increased to 51% at 333 K when the nanotube loading is 0.3 vol%. Classical macroscopic models fail to predict the measured thermal conductivity enhancement precisely. The possible mechanism for the enhancement observed is attributed to the percolation of nanotubes to form a three-dimensional structure. Indirect effects of Brownian motion may assist the formation of percolating networks at higher temperature thereby leading to further enhancements at higher temperature.

THERMAL CONDUCTIVITY ENHANCEMENT OF MATERIAL FOR CALCIUM CHLORIDE/WATER THERMOCHEMICAL ENERGY STORAGE

2018 ◽  
Author(s):  
Takuma Ohtaki ◽  
Maho Mitsuo ◽  
Takayuki Terauchi ◽  
Hiroshi Iguchi ◽  
Keiko Fujioka ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Calcium Chloride ◽  
Thermal Conductivity Enhancement ◽  
Conductivity Enhancement ◽  
Chloride Water

scholarly journals Anomalous thermal conductivity enhancement in low dimensional resonant nanostructures due to imperfections

Nanoscale ◽  
2021 ◽  
Author(s):  
Hongying Wang ◽  
Yajuan Cheng ◽  
Zheyong Fan ◽  
Yangyu Guo ◽  
Zhongwei Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Energy Conversion ◽  
Thermal Conductivity Enhancement ◽  
Heat Management ◽  
Thermoelectric Energy Conversion ◽  
Conductivity Enhancement ◽  
Thermoelectric Energy ◽  
Low Dimensional

Nanophononic metamaterials have broad applications in fields such as heat management, thermoelectric energy conversion, and nanoelectronics. Phonon resonance in pillared low-dimensional structures has been suggested to be a feasible approach...

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