Thermal Energy storage system with enhanced transition array

Abstract

This invention describes the design and applications of a thermal storage system with desirable thermo physical and kinetic properties for various applications including architectural design, increasing thermal mass of building envelops and climate control.

Description

CROSS REFERENCES OF RELATED APPLICATION[0001]This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 261,959, filed on Dec. 2, 2015, the specifications of which are hereby incorporated.FIELD OF THE DISCLOSURE[0002]This disclosure relates to a phase change thermal energy storage system for climate control environments, building structures, energy management and safe transport of temperature sensitive materials and application thereof.BACKGROUND[0003]The present invention relates to the field of thermal energy storage and use of materials that can capture and release energy upon phase transition.[0004]Phase change materials (PCMs) or phase change energy receptors are materials that store / release heat during phase transition without a rise in their own temperature. These features make PCMs ideal to capture and store heat for many applications including architectural design, increasing thermal mass of building envelops, thermal underlayment, climate cont...

AI Technical Summary

Benefits of technology

[0020]Another advantage of the invention is the high loading of phase change material receptor in the large area network of the holding media matrix where neat liquid PCM is directly loaded forming an array of crystallization islands within the media layer. Furthermore, the high density and higher stability of pure PCM compositions (without thickening agents, polymerization and molecular modification) provide high thermal storage per unit volume and reduces volume changes during the melting and solidification cycles at reduced cost.

[0021]The 3-D media member is an inert media matrix of large surface area and high absorption affinity towards aqueous and non-aqueous compositions and is used to contain PCMs of varying temperatures ranging from subzero to 150° C. FIG. 1A illustrates one fiber network 1 made from fibers selected from cellulosic ingredients, bamboo fibers, polypropylene, melt blown synthetic polymers and the like. Alternatively, FIG. 1B shows the networking for two or more fibers 2, 3 and formation scheme while FIG. 1C shows the integration of a high absorbing capacity component 4 or an air blown fibrous composition sandwiched between layers of fine fibers 1 and 3 used as the holding matrix for the phase change material. FIG. 2 illustrates one media matrix 4 loaded with phase change energy composition and crystal cores 5, and the layers 1-5 are encapsulated in a sealed flexible barrier film 6, 7 forming thermal energy storage Cell. The cell configuration may be replicated over various lengths and widths as energy storage panels. Selected temperatures of phase change materials are generally designed to create a cooling effect of a few degrees Celsius as heat storage medium. In some embodiments and as mere examples, the preferred transition temperatures include 4, 6, 10, 15, 18, 21, 23, 25, 27, 28, 29, 32, 35, 37, 49° C.

[0022]A simplified representation of the invention comprises a absorbent support or continuous three dimensional fibrous media member impregnated with additive crystal core nucleating sites and PCM selected from inorganic salts and crystalline hydrates, molten salts, inorganic eutectic mixtures, fatty acids/esters, alcohols, organic eutectics, aliphatic hydrocarbons and combinations thereof. Various compositions may be loaded into the media's matrix separately or as mixtures of the phase change material. Alternatively, PCM additives may be added with the phase change material and within the support media matrix. The addition of nucleating agents serves as crystal core and anchoring sites for crystal growth while distributed within the media microstructures as well as within the fibrous ma

Problems solved by technology

Organic PCMs have low density per volume, low thermal conductivity and are generally flammable.

Inorganic phase change materials such as salt hydrates are known for their heat of high fusion and storage density but suffer from congruent melting and irreversible processes.

Most have slow or poor nucleating properties which result in subcooling where they solidify at much lower temperature than their general melting point.

Unfortunately the formation of lower hydrate forms lead to severe stratification and water phase separation causing solid salts to fall to the bottom of the enclosure.

Such undesired process deprives the top layer from the useful phase change material originally introduced and induces subcooling

Images