الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The use of a latent heat storage system by Phase Change Materials (PCMs) is an
effective method of storing thermal energy. This work is carried out to study the
melting behavior of pure PCMs and Nano Composite-Enhanced Phase-Change
Materials (NEPCMs) experimentally.
The PCM used in the present study is paraffin wax and the heat transfer fluid,
HTF is water. A test rig is designed and constructed to store thermal energy in
PCM contained in a vertical cylinder of 300 mm inner diameter and 600mm
height. A copper coil of 100 mm outer diameter and 300mm height is fitted
concentrically inside the cylinder and HTF is passed upward through the coil.
Experiments are performed for different inlet temperatures of HTF of 70⁰C, 80⁰C
and 90⁰C and for different volume flow rates 5 LPM, 10 LPM and 15 LPM. The
temperature distribution in both liquid and solid phases is measured. Melting
volume fraction with time is estimated. The transient temperature distribution
inside the test material during the phase change process is obtained. A significant
effect of the inlet HTF temperature and volume flow rate on the paraffin melting
process is observed.
The production of NEPCMs by mixing paraffin wax with alumina (Al2O3), are
dispersed into three concentrations of 5.0, 7.5 and 10.0 wt%. Experiments
performed to evaluate the effects of varying concentrations of the Nano-additives
on the thermal energy storage characteristics of NEPCMs. The experimental
results demonstrate that 10.0 wt% concentration is more effective than the other
additives concentrations in enhancing both the heat conduction and thermal
storage performance of paraffin for most of the experimental parameters. The
molten volume fraction (MF) and thermal energy stored percentage (TES%) is
correlated with Fourier number (Fo), Stefan number (Ste), Rayleigh number (Ra)
and volume fraction of Nano particles in the PCM (x).