Phase-change materials (PCMs) can be used for thermal energy storage. PCMs absorb and release large amounts of energy as they change phase from solid to liquid and back. This latent heat storage allows PCMs to store more energy per unit volume compared to sensible heat storage methods. Effective PCMs for thermal energy storage applications should have suitable melting temperatures, heat of fusion, thermal and mechanical stability over repeated phase changes, and acceptable costs. However, challenges remain regarding material compatibility, conditioning, safety, and cost-effectiveness compared to other thermal energy storage options.

1. A (BRIEF) PREVIEW OF PHASE-CHANGE MATERIAL
AS THERMAL ENERGY STORAGE
MD.FAZLA RABBI
ROLL: 1405113
Dr. Mohammad Ariful Islam
Professor
Department of mechanical
engineering
Submitted By Submitted To
Khulna University of Engineering & Technology

2. Thermal energy storage –Why do we need it ?
Energy demands vary on daily, weekly and seasonal bases. TES is helpful for balancing
between the supply and demand of energy.
Thermal energy storage (TES) is defined as the temporary holding of thermal energy in
the form of hot or cold substances for later utilization.
TES systems deal with the storage of energy by cooling, heating, melting, solidifying or
vaporizing a material and the thermal energy becomes available when the process is
reversed.
TES system for a particular application depends on storage duration, economics, supply
and utilization temperature requirements, storage capacity, heat losses and available
Space.

3. Thermal Energy Storage types

4. Latent Heat Storage
Latent heat is energy released or absorbed by a body during a constant-temperature process.
An example is latent heat of fusion for a phase change, melting, at a specified temperature and
pressure.
 Q is the amount of energy released or absorbed during the change of
phase of the substance
 L is the specific latent heat for a particular substance
Specific latent heats of Fusion = 334
KJ/Kg
specific heat CP =4.18 KJ/(kg⋅K)

5. • Definition
A phase-change material (PCM) is a substance presenting a high heat of fusion, and capable of storing and
releasing large amounts of energy. Heat energy is absorbed or released when the material changes from
solid to liquid phase and vice versa, thus, being classified as latent heat storage (LHS) units.

6. • Latent heat

7. Phase change material-Classification

8.  Melting temperature
 latent and sensible heat capacities
 Thermal stability, mechanical stability
 Cyclic property degradation
 Heat transfer characteristics
 Cost
 Corrosiveness
 Ozone depleting potential
 Fire hazard
 Ease of encapsulation
Selection Criteria for PCM material

9. Challenges with Phase change materials
 Material Compatibility
 Material Properties and Thermal Performance
 Packaging for Use
 Conditioning for Use
 Cost and Availability
 Health, Safety and Disposal