Electrically conductive carbon nanofiber/paraffin wax composites for electric thermal storage

2012 ◽  
Vol 64 ◽  
pp. 62-67 ◽  
Author(s):  
Kun Zhang ◽  
Baoguo Han ◽  
Xun Yu
Author(s):  
Monica F. Bonadies ◽  
Son H. Ho ◽  
J. S. Kapat

When collecting the energy of the sun for domestic use, there are several options, which include photovoltaic cells and evacuated tube collectors. Arrays of evacuated tube collectors are used to heat water for domestic applications, supplementing the use of a typical hot water heater, while photovoltaic cells transform the sun’s radiation into electricity. The benefit of the tube collectors is that they supplement an appliance that uses a fairly large amount of electricity when compared to others in an average home. However, the collectors cannot operate during the night time and produce more hot water than needed at their peak operation point. A thermal storage unit can be used to even out the conversion of energy throughout the day to solve this problem. This study proposes a system using paraffin wax to store thermal energy collected during the day by melting the wax. The system makes use of a finned heat exchanger, with paraffin wax on the shell side, and glycol on the tube side as the heat transfer fluid. It also includes a separate loop for water to flow through and receive thermal energy from the melted wax. Although the wax used in the study is quite effective at storing thermal energy, it has the problem of low conductivity. So, fins are added to the storage and extraction loops to increase the wax’s thermal conductivity. The fins not only help to melt the wax more quickly but also act as nucleation sites when the wax freezes. Once all the wax is melted, energy can be exchanged from it to heat water. When creating such a unit, it is useful to have simulation tools to guide its design. One such tool is FLUENT, which will be used in this study to create a simulation of part of the unit. The simulation will be compared to experimental data from a prototype unit and evaluated based upon its strengths and weaknesses.


2008 ◽  
Vol 85 (8) ◽  
pp. 1105 ◽  
Author(s):  
Luyi Sun ◽  
Jonathan Y. O'Reilly ◽  
Chi-Wei Tien ◽  
Hung-Jue Sue

2018 ◽  
Author(s):  
Basant Singh Sikarwar ◽  
A. Chopra ◽  
Mohit Bhandwal ◽  
M. Kumar ◽  
D. K. Avasthi

2017 ◽  
Vol 9 (16) ◽  
pp. 14207-14215 ◽  
Author(s):  
Shuying Wu ◽  
Jin Zhang ◽  
Raj B. Ladani ◽  
Anil R. Ravindran ◽  
Adrian P. Mouritz ◽  
...  

Author(s):  
Seok Chang Kang ◽  
Ji Sun Im ◽  
Sei-Hyun Lee ◽  
Tae-Sung Bae ◽  
Young-Seak Lee

2015 ◽  
Vol 19 (5) ◽  
pp. 1699-1708 ◽  
Author(s):  
Hafiz Ali ◽  
Arslan Bhatti ◽  
Muzaffar Ali

The performance of a double pass solar air heater was experimentally investigated using four different configurations. First configuration contained only absorber plate whereas copper tubes filled with thermal storage medium (paraffin wax) were added on the absorber plate in the second configuration. Aluminum and steel rods as thermal enhancer were inserted in the middle of paraffin wax of each tube for configurations three and four respectively. Second configuration provided useful heat for about 1.5 hours after the sunset compared to first configuration. Configurations three and four provided useful heat for about 2 hours after the sunset. The maximum efficiency of about 96% was achieved using configuration three (i.e. using Aluminum rods in the middle of copper tubes filled with paraffin wax).


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