What is a heat exchanger used for?

Heat exchangers exchange heat in the thermal storage which is stored and retrieved later or can be used as a pre-heating or post-heating devices to save energy. Criteria of design of heat exchangers for various thermal energy storage applications along with their various components are being elaborated.

What is a heat exchanger in thermal energy storage?

On the other hand, the heat exchanger in thermal energy storage corresponds to the structure obtained after morphing through which energy flows from a source, usually the thermal fluid, to the storage material (e.g. a solid or a phase-change material, PCM).

Why are heat exchangers a problem in thermal energy storage?

Still, the main challenge is the design of heat exchangers, as the engineering system that enables the flow of energy from the sources (renewable and non-renewable) to the TSM, disregarded in recent comprehensive reviews on thermal energy storage [ 6, 7 ].

How effective is a heat exchanger?

As mentioned in Section 2.5, the effectiveness of heat exchanger is usually regarded as an ideal value in previous studies, that is, it is set to be equal in energy storage and energy release phases and is not affected by other parameters.

How do thermal energy storage systems work?

Thermal energy storage systems follow two thermodynamic processes using the sensible heat of the energy storage material, or, besides the sensible heat, also the latent heat, as in Phase-Change Material (PCM).

What are the different approaches to thermal energy storage?

There are two basic approaches to thermal energy storage. One using the sensible heat without phase-change (SHS - Sensible Heat Storage), and another using the sensible heat and phase-change (LHS - Latent Heat Storage), as depicted in Figure 1. The thermal balance describing each approach is given by Figure 1.