Table of Contents
What are phase change materials examples?
There are two principal classes of phase change material: organic (carbon-containing) materials derived either from petroleum, from plants or from animals; and salt hydrates, which generally either use natural salts from the sea or from mineral deposits or are by-products of other processes.
What are PCMs used for?
Phase change materials (PCMs) are able to absorb, store and release large amounts of latent heat over a defined temperature range when the material changes phase or state. A fabric containing a PCM can act as a transient thermal barrier which regulates the heat flux.
What is organic phase change material?
An organic phase change material (PCM) possesses the ability to absorb and release large quantity of latent heat during a phase change process over a certain temperature range. The use of PCMs in energy storage and thermal insulation has been tested scientifically and industrially in many applications.
What is the use of phase change materials?
Today, the application of phase change materials (PCMs) has developed in different industries, including the solar cooling and solar power plants, photovoltaic electricity systems, the space industry, waste heat recovery systems, preservation of food and pharmaceutical products, and domestic hot water.
What are different phase changes?
Melting, freezing, vaporization, condensation, sublimation, and deposition are six common phase changes.
What are the advantages of phase change material?
The advantages of these materials are: high latent heat values, non-flammable, low-cost and readily available. However, the disadvantages of inorganic PCMs have led to the investigation of organic PCMs. Some of these disadvantages are corrosiveness; instability, improper re-solidification, and a tendency to super cool.
What are organic PCMs?
Organic PCMs include paraffins, fatty acids and polyethylene glycol (PEG). They present a congruent phase change, they are not dangerous, and they have a good nucleation rate. Table 13.1 presents the thermal properties of organic materials found in the literature, which may meet the specifications listed above.
Does phase change material work?
Phase change materials work because of the curious physics of materials around their melting point. Take water for example. It will only take about 4.2kJ of heat to raise the temperature of one litre of liquid water by one degree.
What is the importance of phase change?
Phase changes, such as the conversion of liquid water to steam, provide an important example of a system in which there is a large change in internal energy with volume at constant temperature.
Who invented phase change material?
Stanford Ovshinsky
While Stanford Ovshinsky is generally credited as the inventor of phase change materials for information storage, the discovery of phase changing electrical char- acteristics dates back to the early 1900s in the little known and seldom cited pio- neering work of Alan Tower Waterman of Yale University.