Abstract:
In order to overcome the increasing demand-supply energy gap due to the rapid
urbanization, labor productivity, consumerism, and depletion of fossil fuel resources,
there is a need for the development of technologies with renewable energy sources.
Thermal energy demand can be met by utilizing thermal energy storage (TES) systems
which are capable of storing the thermal energy from waste heat and renewable energy
resources such as solar energy. Integration of TES in existing systems can help to
decrease the carbon footprints, as well as, in order to overcome the intermittency of
renewable energy resources. Phase change materials (PCMs) are one of the most
appropriate materials for effective utilization of thermal energy from the renewable
energy resources. As evident from the literature, development of PCMs is one of the
most active research fields for TES with higher efficiency. Therefore, multiple fatty
acids based eutectic phase change materials (EPCMs) are developed for low- to
moderate-temperature applications. In particular, palmitic acid, myristic acid, stearic
acid, lauric acid, and commercial bio-based PCM; PureTemp68 are used for preparing
eutectic mixtures. The eutectic point of each eutectic mixture is determined using
Schrader equation along with its thermophysical properties. Ten different eutectic
mixtures are prepared in accordance with eutectic point obtained from the phase
diagrams by melt blending followed by ultrasonication. The latent heat, melting point
as well as the specific heat capacity of the EPCMs are determined by Differential
Scanning Calorimetry (DSC). Chemical structure of these EPCMs is determined by
using Fourier Transformation Infrared Spectroscopy (FT-IR). Latent heat thermal
energy storage (LHTES) system comprising of commercial grade paraffin wax as a
PCM is designed and fabricated. A test bench is developed for studying the charging
and discharging cycles with effect to the operating parameters. Some approaches have
been studied in the past to enhance the thermal conductivity with the goal to shrink the
charging time of the particular PCMs. A novel approach is adopted in the design of the
LHTES system comprising of the copper coil with fins, to meet the requirements
considering stability, and the safety in the operation of system.
