Phase Change Energy Storage Materials - Phase Change Heat Storage

There are two types of phase change heat storage methods: sensible heat energy storage and latent heat energy storage.

Sensible heat energy storage：

The process of storing or releasing heat by raising or decreasing the temperature of a material by using the heat capacity of a material.

--Heat capacity

For a closed system with no phase change or chemical change, and the non-volumetric work is equal to zero, the heat absorbed by the system per increase in unit thermodynamic temperature (1K).

Characteristics of sensible thermal energy storage：

1.Advantages

• The principle is simple, the material source is abundant, the cost is low, the system structure is simple, and the operation is convenient

2.Disadvantages

• The energy storage density is small and the energy storage device is large

Latent heat energy storage:

It is carried out by using the energy absorption and release that accompanies the transition of the state of matter.

Latent heat of phase change:

The absorption or release of the energy that accompanies the phase transition process is called the latent heat of phase transition.

Advantages of latent heat energy storage:

Much higher energy storage density than sensible thermal energy storage.

• Such as: water

When water boils at atmospheric pressure, its latent heat is about 2260kJ/kg, and when the ice melts, its latent heat is 355kJ/kg.

The sensible heat of water heated from 20°C to 40°C at a pressure of 1 atmosphere with a temperature difference of 20°C is only 84 kJ/kg

Phase transformation forms of energy storage materials