Integration of particulated encapsulated phase change materials in a conventional flat-plate solar collector for the production of domestic hot water

A group of materials that can be used as latent heat storage media are the phase change materials (PCMs). PCMs are substances designed to undergo a nearly isothermal phase transition at specific temperatures and thus, releasing or absorbing thermal energy to and from the environment. PCMs according to their chemical nature, are classified as: i) Organic: paraffins or non-paraffins such as fatty acids, esters, glycols, and alcohols; ii) Inorganic, which includes alloys and metals but mainly salt hydrates, and finally iii) Eutectics, which are mixtures of PCMs either organic-organic, inorganic-inorganic or inorganic-organic. Organic PCMs, such as paraffins, are widely studied and applied due to their high thermal conductivity, high heat of fusion, low volume change, and low-cost production. Organic PCMs are in general thermally and chemically stable. However, on the negative side, they are flammable, volatile, and have low thermal conductivity. In some cases, their chemical inertness is questionable when in contact with engineering polymer containers. Inorganic phase change materials may have higher thermal conductivity and latent heat of fusion but can be more corrosive in nature, lack thermal stability, and often undergo phase segregation and separation. In order to overcome these problems, encapsulation of PCMs is being successfully developed, providing decreased subcooling, large heat transfer area, and controlling the volume change of the storage materials when the phase transition occurs. The current invention refers to the technical conceptual approach of using encapsulated PCMs in particulated form to fill a compartment thermal storage tank- which envelopes a heat exchanger integrated into a flat-plate solar collector for the production of domestic hot water. The encapsulated PCMs applied in this flat-plate solar collector are either microencapsulated of various types or shape stabilized of various types. The encapsulated PCMs applied we refer to are of particulated or powder form with particle size 5mm and under 5mm capable to flow and effectively fill in the tank. Thus, an effective contact with the elements of the enveloped heat exchanger is achieved improving the efficiency of flat-plate solar collector with integrated LHS tanks for the production of domestic hot water. The as claimed encapsulated PCMs will be of the following types: organic, inorganic, eutectic. The encapsulated phase change material is configured to exchange thermal energy as latent heat involving a phase transformation within the temperature range of 25 degrees Celsius to 90 degrees Celsius.