Encapsulation of thermal energy storage media

• US 9,879,166 B1
• Filed: 06/16/2015
• Issued: 01/30/2018
• Est. Priority Date: 06/16/2014
• Status: Active Grant

• Current Assignee: University of South Florida (State University System of Florida)
• Original Assignee: University of South Florida (State University System of Florida)
• Inventors: Goswami, Dharendra Yogi, Stefanakos, Elias K., Jotshi, Chand K., Dhau, Jaspreet
• Primary Examiner(s): Stanley, Jane L
• Application Number:
  US14/741,427
• Time in Patent Office: 959 Days
• Field of Search: 252 71
• CPC Class Codes: C04B 2235/3201 Alkali metal oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3427 Silicates other than clay, e.g. water glass
• CPC Class Codes: C04B 2235/94 Products characterised by their shape
• CPC Class Codes: C04B 33/34 combined with glazing
• CPC Class Codes: C04B 35/00 Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: C04B 35/10 based on aluminium oxide
• CPC Class Codes: C04B 35/14 based on silica
• CPC Class Codes: C04B 38/009 Porous or hollow ceramic granular materials, e.g. microballoons C04B18/027, C04B20/002 take precedence
• CPC Class Codes: C09K 5/04 the change of state being from liquid to vapour or vice versa
• CPC Class Codes: C09K 5/06 the change of state being from liquid to solid or vice versa
• CPC Class Codes: C09K 5/063 Materials absorbing or liberating heat during crystallisation; Heat storage materials
• CPC Class Codes: F28D 20/00 Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00

Abstract

In one embodiment, a method for fabricating a ceramic phase change material capsule includes forming a hollow ceramic capsule body having a filling hole, filling the ceramic capsule body with one or more phase change materials via the filling hole, and closing and sealing the filling hole.

Claims

1. A method for fabricating a ceramic phase change material capsule, the method comprising:

forming a hollow ceramic capsule body having a filling hole;

heating the ceramic capsule body to at least partially sinter the ceramic capsule body;

filling the ceramic capsule body with one or more phase change materials via the filling hole;

closing the filling hole with a plug to form a closed capsule; and

heating the closed capsule to a temperature above a melting point of the plug but below a melting point of the one or more phase change materials so as to melt the plug and seal the capsule without melting the one or more phase change materials.

2. The method of claim 1, wherein forming a ceramic capsule body comprises immersing the ceramic capsule body in a solution comprising a sealing material.

3. The method of claim 2, wherein the sealing material comprises an alkali metal silicate, a borate, or a mixture thereof.

4. The method of claim 1, wherein forming a ceramic capsule body comprises mixing a sealing material with a ceramic material to form a material used to form the ceramic capsule body.

5. The method of claim 1, wherein forming a ceramic capsule body comprises coating interior surfaces of the ceramic capsule body with a solution comprising a sealing material.

6. The method of claim 5, wherein the sealing material comprises an alkali metal silicate, a borate, or a mixture thereof.

7. The method of claim 1, wherein closing and sealing the filling hole comprises closing the filling hole with a plug of sealing material.

8. The method of claim 1, wherein closing and sealing the filling hole comprises closing the filling hole with a plug of ceramic material.

9. The method of claim 1, wherein filling the ceramic capsule body with one or more phase change materials comprises filling the ceramic capsule body with two phase change materials in a manner in which they do not mix with each other.

10. The method of claim 9, wherein filling the capsule body comprises first filling the capsule body with a first phase change material to form a first layer of phase change material and then filling the capsule body with a second phase change material to form a second layer of phase change material that overlies the first layer.

11. The method of claim 10, further comprising physically manipulating the sealed capsule so as to mix the first and second phase change materials together and form a eutectic phase change material.

12. The method of claim 11, wherein the temperature to which the closed capsule is heated is higher than a melting point of the eutectic phase change material.

13. A method for fabricating a ceramic phase change material capsule, the method comprising:

forming a hollow, green ceramic capsule body having a filling hole;

heating the green ceramic capsule body to at least partially sinter the ceramic capsule body;

filling the ceramic capsule body with two or more phase change materials via the filling hole in a manner in which the phase change materials do not mix with each other within the ceramic capsule body;

closing the filling hole with a plug to form a closed capsule; and

heating the closed capsule to a temperature above a melting point of the plug, below melting points of the two or more phase change materials, and above a melting point of a eutectic phase change material that results when the two or more phase change materials are mixed together, so as to melt the plug and seal the capsule without melting the two or more phase change materials; and

physically manipulating the sealed capsule so as to mix the two or more phase change materials together and form the eutectic phase change material.

14. The method of claim 13, further comprising sealing the ceramic capsule body using a sealing material that is either mixed with ceramic material that is used to form the ceramic capsule body or is applied to the ceramic capsule body.

15. The method of claim 14, wherein the sealing material comprises an alkali metal silicate, a borate, or a mixture thereof.