Phase Change Materials (PCM): An Innovative Solution for Heat Recovery

Materials PCM: an innovative solution for heat recovery

In the previous article, we introduced thermal batteries, outlining their definition, operation, and the advantages they can offer, especially in an energy context that is increasingly oriented towards alternative sources.

We discussed thermal batteries as heat accumulators, devices capable of absorbing and subsequently releasing thermal energy when needed. For example, to manage the demand for heating and cooling in residential and industrial settings.

Since these devices not only store thermal energy but also recover it when needed, they are often referred to as heat recovery systems. Let's delve deeper into this concept.

How does a heat accumulator work

As we've explained, a heat accumulator operates on a relatively simple yet effective principle. During periods when there is excess thermal energy available, such as during the day or when the energy demand is low, the system utilizes this energy to heat a material capable of absorbing heat. This material can consist of various substances, including stones, water, sand, or phase change materials like salts and paraffins, which we'll discuss further later on.

Once the material designated for heat accumulation has been heated to the desired temperature, its thermal energy is stored within the device. When it's necessary to release heat, such as during the night or in low temperature conditions, the heat accumulator gradually releases the stored heat into the surrounding environment. This process helps maintain a constant indoor temperature in buildings or provides heat for other purposes without the need for additional heating systems.

Why Heat Recovery is Important

Heat recovery is one of the fundamental actions to increase energy efficiency in end uses, with a direct impact on reducing CO2 emissions in the environment. In addition to recovery for direct use, in recent years, technologies have been developed to recover and reuse heat from industrial processes, especially when the quantities of energy involved and the thermal levels

Recovering Heat with PCM Materials

As heat recovery becomes increasingly important in various contexts, recovering heat through PCM (Phase Change Materials) or phase change materials offers significant advantages. Let's examine them.

As discussed in the previous article, "Complete Guide to Thermal Batteries: How They Work and What Benefits They Offer," one type of thermal battery available on the market utilizes latent heat storage thanks to PCM materials. These materials are composed of organic or inorganic substances with specific thermophysical properties. Common examples include paraffins, non-paraffins (such as fatty acids, alcohols, and glycols), hydrated salts, and metals. They are selected based on their melting temperature and thermal performance according to the desired application.

How do PCM Materials Work?

PCM materials leverage a fascinating and revolutionary property: they can undergo a phase change that transitions them from a solid state to a liquid state (and vice versa) at a specific temperature known as the melting or crystallization temperature. This temperature remains constant throughout the entire phase change process, and the heat absorbed or released during this process is referred to as latent heat, or briefly LHS (Latent Heat Storage).

As they change state, PCM materials absorb or release a considerable amount of thermal energy while maintaining a constant temperature, thereby offering significant advantages in terms of thermal management and temperature regulation.

An example we all know occurs with water. When it reaches a certain temperature (between 0 and 4°C), water undergoes a phase change: from liquid to solid (ice), or vice versa. Heat (latent heat) can be supplied to the ice without increasing its temperature: the supplied energy is only used to melt the solid, and only when it has all turned into liquid does the temperature of the water begin to rise.

The Advantages of Thermal Recovery with PCM Materials

PCM materials represent a promising technology for improving energy efficiency, temperature control, and sustainability in various sectors. For several years, phase change materials have been the subject of growing interest from multiple parties due to the benefits they offer, particularly regarding:

Efficient thermal energy storage: PCM enables the storage of large quantities of thermal energy efficiently, occupying less space compared to other energy storage solutions.
Precise temperature control: Thanks to their ability to maintain a constant temperature during the phase change process, PCM allows for precise temperature control in a variety of applications.
Reduction of energy costs: The use of PCM can help reduce energy costs associated with heating and cooling buildings and industrial systems.

In the upcoming articles, we will delve deeper into the topic of PCM materials, which represent the core business of i-TES. Learn more about i-TES's PCM thermal battery!

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