Eco-friendly temperature system
11713908 · 2023-08-01
Assignee
Inventors
Cpc classification
F25B21/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
H10N19/101
ELECTRICITY
F25B2321/023
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
H10N10/855
ELECTRICITY
F25B2321/0251
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F25B21/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
H10N10/855
ELECTRICITY
Abstract
The present disclosure is related to thermoelectric panels and their use in cooling and heating systems. The cooling/heating systems may include a plurality of thermoelectric panels. The panels may include thermoelectric devices embedded between a housing formed by heat conductive layers and edge structures for preserve a low thermal conductivity volume.
Claims
1. A thermoelectric apparatus, the apparatus comprising: a plurality of thermoelectric panels, each of the thermoelectric panels comprising: a first layer having an inner side and an outer side, wherein the first layer is thermally conductive; a plurality of thermoelectric devices disposed on the inner side of the first layer; a second layer having an inner side and an outer side, wherein the second layer is thermally conductive, and wherein the plurality of thermoelectric devices is disposed on the inner side of the second layer; a plurality of edge structures connected to the first layer and the second layer to form a volume between the first layer, the second layer, and the plurality of edge structures, wherein each of the edge structures comprises: a u-shaped housing of thermal insulation; a gas diffusion resistant layer disposed on the u-shaped housing; and a plurality of thermally non-conductive pillars disposed within the u-shaped housing between parallel sides of the u-shaped housing; an insulated bottom supporting the plurality of thermoelectric panels; and an insulated top supported by the plurality of thermoelectric panels; wherein the plurality of thermoelectric panels and the plurality of edge structures form a closed system.
2. The thermoelectric apparatus of claim 1, wherein the thermoelectric device comprises: a first substrate layer; a first set of metal links disposed on one side of the first substrate layer; a first stage of thermoelements disposed on and in electrical and thermal communication with the first set of metal links and comprising: a first plurality of n-type thermoelements; and a first plurality of p-type thermoelements alternating with the first plurality of n-type thermoelements; a second stage of thermoelements disposed on and in electrical and thermal communication with the first stage of thermoelements and comprising: a second plurality of n-type thermoelements; and a second plurality of p-type thermoelements alternating with the second plurality of n-type thermoelements; a second set of metal links disposed on and in electrical and thermal communication with the second stage of thermoelements; and a second substrate layer disposed on the second set of metal links.
3. The apparatus of claim 2, wherein the apparatus has a front end and a back end and wherein the first stage thermoelement closest to the front end is the same type as the second stage thermoelement closest to the front end.
4. The apparatus of claim 3, wherein the first stage thermoelement closest to the back end is the same type as the second stage thermoelement closest to the back end.
5. The apparatus of claim 2, wherein the thermoelements of the second stage have greater electrical resistances than the thermoelements of the first stage.
6. The apparatus of claim 2, wherein the n-type thermoelements comprise an n-type thermoelectric material comprising at least one of: alloys of Bismuth Telluride and Bismuth Selenide, Bi.sub.2Te.sub.2.7Se.sub.0.3, P-doped SiGe, YbAl.sub.3, P-doped Si, SiGe nanowires, rare earth tellurides, La.sub.3Te.sub.4, Pr.sub.3Te.sub.4, skutterudites, Ba—Yb—CoSb.sub.3, chacogenides, Pb—Sb—Ag—Te, Pb—Te—Se, Mg—Ag—Sb, half-Heusler alloys, and Hf—Zr—Ni—Sn—Sb.
7. The apparatus of claim 2, wherein the p-type thermoelements comprise a p-type thermoelectric material comprising at least one of: alloys of bismuth telluride and antimony telluride, Bi.sub.0.5Sb.sub.1.5Te.sub.3, B-doped SiGe, B-doped Si, SiGe nanowires, Zn.sub.4Sb.sub.3, skutterudites, CeFe.sub.3.5Co.sub.0.5Sb.sub.12, Zintl compounds, Yb.sub.14MnSb.sub.11, rare earth tellurides, Ce.sub.3Te.sub.4, MnSi.sub.1.73, SnSe, PbSbAgSnTe, CePd.sub.3, NaCo.sub.2O.sub.4, half-Heusler alloys, and Nb—Ti—Fe—Sb—Sn.
8. The apparatus of claim 2, wherein the n-type thermoelements comprise Bi.sub.2-xSb.sub.xTe.sub.3 and the p-type thermoelements comprise Bi.sub.2Te.sub.3-ySe.sub.y, where x is between about 1.4 and 1.6 and y is between about 0.1 and 0.3.
9. The apparatus of claim 2, wherein the substrate layer comprises a ceramic.
10. The apparatus of claim 9, wherein the ceramic comprises at least one of: alumina Al.sub.2O.sub.3, aluminum nitride (AlN), berylium oxide (BeO), boron nitride (BN), diamond (C), silicon nitride (SiN), and sapphire (SiC).
11. The apparatus of claim 2, wherein each of the first set of metal links and the second set of metal links comprise at least one of: 1) copper, 2) copper with a coating of nickel, gold, platinum/gold alloy, or silver, 3) nickel with a coating of gold, platinum/gold alloy, or silver.
12. The apparatus of claim 2, wherein each of the n-type and p-type thermoelements comprises: a pair of metal layers; a pair of coating layers disposed between the metal layers; and one of an n-type and p-type thermoelectric material disposed between the pair of coating layers.
13. The apparatus of claim 12, wherein the coating layers comprise at least one of: titanium tungsten (TiW), tantalum nitride (TaN), tantalum (Ta), and nickel (Ni).
14. The thermoelectric apparatus of claim 1, wherein each of the thermoelectric devices further comprises: at least one thermally conductive spacer disposed between the thermoelectric unit and the inner side of at least one of the first inner layer and the second layer.
15. The thermoelectric apparatus of claim 14, wherein a thermal interface layer is disposed between the at least one thermally conductive spacer and the inner face.
16. The thermoelectric apparatus of claim 1, further comprising: a plurality of cooling structures disposed on the outer side of the first layer.
17. The thermoelectric apparatus of claim 1, further comprising: a plurality of cooling structures disposed on the outer side of the second layer.
18. The thermoelectric apparatus of claim 1, further comprising: an air mover positioned to direct air flow over the surface of at least one of the plurality of thermoelectric panels.
19. The thermoelectric apparatus of claim 1, wherein the first layer and the second layer prevent diffusion of gasses.
20. The thermoelectric apparatus of claim 1, further comprising: a thermal insulation layer disposed between and in contact with the first layer and the second layer and that does not obstruct the heat flow across the plurality of thermoelectric devices.
21. The thermoelectric apparatus of claim 20, wherein the thermal insulation layer is made of one of: a vacuum, an aerogel, and air in closed non-convective cells.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) For a detailed understanding of the present disclosure, reference should be made to the following detailed description of the embodiments, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals, wherein:
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
(23)
DETAILED DESCRIPTION OF THE DISCLOSURE
(24) Generally, the present disclosure relates to apparatuses and methods for a refrigeration system, and, in particular, using thermoelectric devices for refrigeration. The present disclosure is susceptible to embodiments of different forms. They are shown in the drawings, and herein will be described in detail, specific embodiments of the present disclosure with the understanding that the present disclosure is to be considered an exemplification of the principles of the present disclosure and is not intended to limit the present disclosure to that illustrated and described herein.
(25)
(26) The apparatus 100 has an interior 140, which may be maintained at a colder temperature than the ambient air as the heat is drawn out through the thermoelectric panels 110. The apparatus 100 may include one or more supports 150 that support the insulated bottom layer 130 and facilitate ambient air flow below the insulated bottom layer 130. The apparatus 100 may include an air mover 160, such as a fan or syn-jet, to direct a flow of air 170 across the outer surface of the thermoelectric panels 110 to enhance the cooling effect by removing heat. In some embodiments, the air mover 160 may be powered by the power supply 180.
(27)
(28) A plurality of cooling structures 240 may be disposed on the outer surface of the first layer 210. Optionally, a plurality of heat absorbing structures 250 may be disposed on the outer surface of the second layer 220. The heat absorbing structures 250 may be of the same or different shape as the outer surface and may include hydrophobic coatings to avoid dew drops and condensates at the surface. The flow of heat into the second layer 220 and out of the first layer 210 are shown by arrows 260. The edge structures 270 enclose the ends of the first layer 210 and the second layer 220 and preserve the vacuum with in volume 280. While the first layer 210 and the second layer 220 are shown in a side view, they are three-dimensional, and the edge structures 270 may surround the layers 210, 220 around their respective edges in order to seal the volume 280 from ambient.
(29) In operation, power is applied from the power source 180 to the panels 110. The thermoelectric devices 230 in the panels 110 produce a temperature differential. The heat 260 is drawn of the second layer 220 and transmitted to the first layer 210, where it is released into the ambient environment, either directly or by way of the cooling structures 240. In some embodiments, heat 260 may follow a pathway to the second layer 220 through a set of heat removal structures 250 on the outer surface 227 of the second layer 220. The vacuum is in the volume 280 is maintained by the layers 210, 220 and the edge structures 270. Heat leakage from the ambient environment back across the panels 110 is reduced or prevented by the vacuum or insulation within the volume 280.
(30)
(31) The edge structure 270 may also include one or more pillars 330 supporting the edge housing 320. The pillars 330 may be made of a material with a high strength to mass ratio and low thermal conductivity. In some embodiments, the pillars may be made of an aerogel, such as Airloy. In some embodiments, the pillars 330 may be about 2 to 3 millimeters in diameter each. The edge housing 320 may be inserted between the first layer 210 and the second layer 220 and joined with a vacuum epoxy layer 340 to prevent an exchange of atmosphere or gases with the volume 280. In some embodiments, the vacuum epoxy layer 340 may be made of an epoxy formulated to meet NASA ASTM E595 low outgassing standards, such as 3M Scotch Weld and Thorlab's Vacuum Epoxy.
(32) The thermoelectric device 230 may include a heat conductive spacer 360 and a thermoelectric converter unit 370. The heat conductive spacer 360 is sized so that the thermoelectric device 230 makes thermal contact with the inner surfaces of both the first layer 210 and the second layer 220. The heat conductive spacer 360 may be made of any suitable thermally conductive material with a compressive yield strength that is the same or greater than the compressive yield strength of the thermoelectric converter unit 370. In some embodiments, the heat conductive spacer 360 is metal. In some embodiments, the heat conductive spacer 360 is copper. A layer of thermal interface material 350 may be disposed between the heat conductive spacer 360 and the first layer 210 to improve thermal conduction between the heat conductive spacer 360 and the first layer 210. The thermal interface material 350 may include a silicone oil. In some embodiments, the thermal interface material 350 may include a silicone oil with embedded nanoparticles of silver or boron nitride.
(33)
(34) The n-type thermoelements 420 may be made of, but are not limited to, alloys of Bismuth Telluride and Bismuth Selenide such as Bi.sub.2Te.sub.2.7Se.sub.0.3, P-doped SiGe, YbAl.sub.3, P-doped Si and SiGe nanowires, rare earth tellurides such as La.sub.3Te.sub.4 and Pr.sub.3Te.sub.4, skutterudites such as Ba—Yb—CoSb.sub.3, chacogenides such as Pb—Sb—Ag—Te, Pb—Te—Se, and Mg—Ag—Sb, and half-Heusler alloys such as Hf—Zr—Ni—Sn—Sb. The p-type thermoelements 430 may be made of, but are not limited to, alloys of Bismuth Telluride and Antimony Telluride such as Bi.sub.0.5Sb.sub.1.5Te.sub.3, B-doped SiGe, B-doped Si and SiGe nanowires, Zn.sub.4Sb.sub.3, skutterudites such as CeFe.sub.3.5Co.sub.0.5Sb.sub.12, Zintl compounds such as Yb.sub.14MnSb.sub.11, rare earth tellurides such as Ce.sub.3Te.sub.4, MnSi.sub.1.73, SnSe, PbSbAgSnTe, CePd.sub.3, NaCo.sub.2O.sub.4, half-Heusler alloys such as Nb—Ti—Fe—Sb—Sn. In some embodiments, the n-type and p-type thermoelements 420, 430 may include different ratios of Bismuth Telluride, Antimony Telluride, and Bismuth Selenium (Bi.sub.2Te.sub.3:Sb.sub.2Te.sub.3:Bi.sub.2Se.sub.3 in the ratio of, for example, 1:3:0 or 10:0:1). In some embodiments, a p-type thermoelement 430 may include Bismuth Antimony Telluride alloy (Bi.sub.2-xSb.sub.xTe.sub.3) and an n-type thermoelement 420 may include a Bismuth Tellurium Selenide alloy (Bi.sub.2Te.sub.3-ySe.sub.y), where x and y vary between about 1.4-1.6 and about 0.1-0.3 respectively. The substrate layer 410 may include one of: a ceramic, an insulator and metal combination, and an insulator and semiconductor combination. Suitable ceramics may include, but are not limited to, one or more of: alumina Al.sub.2O.sub.3, aluminum nitride (AlN), berylium oxide (BeO), boron nitride (BN), diamond (C), silicon nitride (SiN), and sapphire (SiC). Suitable insulator and metal combinations may include, but are not limited to, an insulator made of one of: polymide, parylene, anodized aluminum, anodized molybdenum, CVD alumina, plated ceramics, and parylene or polymide-coated anodized alumina combined with a metal made of one of: aluminum, copper, nickel, molybdenum, molybdenum-copper alloy, tungsten-copper alloy, and copper-aluminum composite. In some embodiments, the insulator layer may have a thickness of less than 10 micrometers. Suitable insulator and semiconductor combinations may include, but are not limited to, an insulator made of one of: thermal silicon oxide, CVD silicon oxide, and silicon nitride (SiN) combined with a semiconductor made of one of: silicon and silicon carbide (SiC). The selection of a substrate layer material may impact performance and reliability of the thermoelectric converter cell 370 due to heat expansion coefficients of the materials used. The metal links 440 may be made of one of: copper, a copper or nickel layer with nickel/gold coating, a copper or nickel layer with platinum/gold alloy, gold, or silver.
(35) The p-type thermoelements 430 include thermoelement 433, thermoelement 435, and thermoelement 437, each of which have different electrical resistance. In some embodiments, the different electrical resistances are achieved by the thermoelements 433, 435, 437 having different cross-sectional areas (which appears a difference in width in the side view). As shown, the cross-sectional area of the thermoelement 433 is greater than the cross-sectional area of the thermoelement 435. The cross-sectional area of thermoelement 437 is less than the cross-sectional area of either thermoelements 433 and 435. Likewise, the n-type thermoelements 420 include thermoelement 423, thermoelement 425, and thermoelement 427, each of which have different electrical resistance. In some embodiments, the different electrical resistances are achieved by the thermoelements 423, 425, 427 having different cross-sectional area (which appears a difference in width in the side view). The cross-sectional area of the thermoelement 423 is greater than the cross-sectional area of the thermoelement 425. The cross-sectional area of thermoelement 427 is less than the cross-sectional area of either thermoelements 423 and 425. The different cross-sectional areas of the thermoelements 423, 425, 427, 433, 435, 437 correspond to the different resistances, and, thus, amounts of electrical currents passing through the respective elements. The thermoelements 423, 433 may be sized larger for higher COPs and ΔT.sub.max. Also, the ratio of cross-sections of p-type elements 425, 427 and n-type elements 435, 437 may be changed to increase or decrease the COPs and ΔT.sub.max. In some embodiments, the different resistances in thermoelements 423, 425, 427, 433, 435, 437 may be achieved by varying the thicknesses of the thermoelements 423, 425, 427, 433, 435, 437 as would be understood by a person of skill in the art.
(36)
(37)
(38)
(39)
(40) In operation, the air flow path 170 moves parallel to the surface of the first layer 210 gathering heat conducting or radiating from the surface of the first layer 210. When the air flow path 170 intersects a fin 700, the warmer air is redirected away from the first layer 210, thus removing heat. Cooler air then replaces the warmer air in the air flow 170 path to both cool the first layer 210 and to remove more heat.
(41)
(42)
(43)
(44)
(45)
(46) In operation, electrical power supplied to the thermoelectric devices 230 causes a temperature differential between the first layer 1110 and the second layer 1120. In the case of refrigeration, the cold outer surface 1127 of the second layer 1120 removes heat 260 from the volume 1130. The heat 260 is transmitted to the first layer 1110, where it may be removed to ambient, either through direct convection or through transmission to the cooling structures 240. Heat leakage back into the volume 1130 from ambient is reduced or prevented by the low thermal conductivity of the volume 1140 either by the presence of a vacuum or the thermal insulation.
(47)
(48) While the disclosure has been described with reference to exemplary embodiments, it will be understood that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications will be appreciated to adapt a particular instrument, situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.