Modification of Ternary Nitrate Mixture's Thermal Properties

<p>The purpose of this research is to determine whether the addition of multiwalled carbon nanotubes (MWCNT) and an aluminum dopant to a ternary nitrate mixture will result in favorable properties for use in a concentrated solar power system as a heat transfer fluid (HTF) or thermal energy storage (TES) material. The properties that were investigated were latent heat, average specific heat capacity and rate of heat flow. The study reviews the changes during heating and cooling cycles and heat capacity of the sample. A ternary nitrate salt mixture (Ca(NO3)2 ·4H2O+KNO3+ NaNO3) at equal ratio embedded with MWCNTs and doped with Sol-gels were prepared and tested. The weight percentage of MWCNTs and aluminum dopant was approximately 1-2% each. After the samples were mixed together, they were placed in a vacuum furnace for eighty minutes at 450°C and then cooled down to room temperature. In order to minimize the moisture absorption the samples were kept in a sealed desiccator. These hybrid phase change materials were then tested using a differential scanning calorimeter (DSC) through heating and cooling cycles in the range of 0°C to 390°C. The latent heat of the samples was measured from the cooling exothermic curve from the DSC. Scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS) and Raman spectroscopy were used to analyze the nitrate mixtures as to their composition and surface appearance. From the DSC data it appears as though the rate of heat flow decreases with the addition of MWCNTs and Aluminum dopant. The average specific heat capacity also was reduced by the addition of MWCNTs according to the average data from 5 samples. The EDS analysis confirmed the composition of the mixtures. SEM analysis revealed the distribution of MWCNTs and the structure of the nitrates.</p>

Name thesis:degree_name

Master of Science in Applied Engineering (M.S.A.E.)

Level thesis:degree_level

Thesis (restricted to Georgia Southern)

Discipline thesis:degree_discipline

Department of Mechanical Engineering

Year dc:date.available

2015

Author dc:creator

• Hood, Richard W

Contributors dc:contributor

• Gustavo Molina
• David Calamas
• Rafael Quirino

• ETD
• Nanocomposites
• Nitrate mixture
• Latent heat
• Specific heat capacity
• Rate of heat flow
• Carbon nanotubes
• Nanoscience and Nanotechnology

Repository record dc:identifier

https://digitalcommons.georgiasouthern.edu/etd/1309

OAI identifier oai:identifier

oai:digitalcommons.georgiasouthern.edu:etd-2383