Design and analysis of compound structures integrated with bio-based phase change materials and lattices obtained through additive manufacturing

Abstract

Phase change materials (PCMs) are an interesting category of materials employed in latent heat thermal energy storage, such as ad hoc designed heat exchangers. Nowadays, there are several typologies of PCMs, which derive from the wastes of the agricultural industry, which could be used for this kind of design. Each material made of biological waste has a different melting/solidification point and latent heat of fusion/solidification, which means flexibility of design on the heat exchangers by considering the different thermal proprieties of the chosen material. Also, using recycled material from wastes can lead to an overall improvement of the resources and goes hand in hand with the need of today’s society to aim more and more at a Circular Economy. The industrial development of this kind of material is limited by its thermal properties, such as poor thermal conductivity both in liquid and solid phases, leading to low heat transfer effectiveness. To overcome these limitations, in this paper, the bio-based PCMs were integrated into a metallic reticular structure made of copper and aluminium and realised through Indirect-Additive Manufacturing, to improve the overall thermal conductivity of the system and increase the efficiency of the heat transfer. Four compound structures filled each time with four different PCMs were realised and tested, in order to thermally characterise each combination of materials used and choose which one has an overall better thermal behaviour. The results showed how the thermal storage/release was improved by 10% for the copper reticular structure, even if must be considered the tradeoff between better thermal management and the increase of the costs and the weight of the designed heat exchanger.

Advanced Materials and Additive Manufacturing for Phase Change Thermal Energy Storage and Management: A Review

“…[ 159 ] These efforts produce metal structures that are generally fabricated to be porous for backfilling with PCM and focus on optimizing geometries that encourage rapid charging/discharging of the PCM. [ 86–88,134–164,168 ] The backfilling of metallic AM devices with bulk PCM capitalizes on high thermal conductivities, leak‐resistant structures, and considerable PCM volumes for high energy capacity. A few AM metallic structures have sought to use the metal as the PCM.…”

“…[113,129,145] Other PCMs used include a sugar alcohol, fatty alcohol, fatty acid, and water. [116,132,137,146,147] Commercialized PCMs are routinely utilized given the variety of transition temperatures and are available both in neat [87,93,94,112,[148][149][150][151][152][153][154][155][156][157][158][159][160][161][162][163] and microencapsulated forms. [97,111,112] In an example of a metal PCM, researchers capitalized on the solid-state transition of a nickel titanium alloy from monoclinic Martensite configurations to a cubic Austenite lattice for AM metallic parts.…”

Open-Source Library of Tissue Engineering Scaffolds

“…In any case, joining forces with colleagues and working towards standardized sets of structures for tissue scaffolds and lightweight design in general is needed. Together with the pioneering CAD libraries of lattice geometries and scaffolding structures already introduced, important recent studies [52][53][54][55][56][57][58], dealing with additively manufactured high-performance structures in biomaterials, ceramics and alloys, also outline how to further progress in this fascinating field.…”

Structural, Electrical, and Mechanical Properties Investigation of Open-Cell Aluminum Foams Obtained by Spark Plasma Sintering and Replication on Polyurethane Template

“…A variety of fabrication processes have been developed to produce metal foams, in particular aluminum foams [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. The common processes are either via the addition of a foaming agent into molten aluminum alloy or through bubbling gas into a molten aluminum alloy.…”