Claims:1. A thermal energy storage and heat transfer device (100) comprising:
an encapsulation (102) defining a monolithic structure enclosing a volume, the encapsulation (102) including:
a first flexible large face (104);
a second flexible large face (106) facing the first large face (104);
a plurality of small faces (108) coupled with the first flexible large face (104) and the second flexible large face (106); and
a phase changing material (PCM) enclosed within the encapsulation (102), the phase changing material (PCM) is charged or discharged based upon a thermal energy exchange, wherein the first flexible large face (104) and the second flexible large face (106) curve towards each other during discharge phase of the phase changing material (PCM), and wherein the first flexible large face (104) and the second flexible large face (106) curve away from each other during a charge phase of the phase changing material (PCM).
2. The device (100) as claimed in claim 1, wherein the discharged phase of the phase changing material (PCM) is a liquid phase, and charged phase of the phase changing material (PCM) is a solid phase.
3. The device (100) as claimed in claim 1 is a polymer based device.
4. The device (100) as claimed in claim 1, wherein the encapsulation (102) includes a plurality of ribs or stiffeners (112).
5. The device (100) as claimed in claim 1, wherein the volume of the encapsulation (102) increases upon solidification of the phase changing material (PCM).
6. The device (100) as claimed in claim 5, wherein the encapsulation (102) attains shape of a regular cuboid upon solidification of the phase changing material (PCM).
7. The device (100) as claimed in claim 1, wherein at least one of the plurality of small faces (108) includes a plurality of openings (114), the openings being configured for any or a combination of replenishment of the phase changing material (PCM), escapement of air.
8. The device (100) as claimed in claim 5, wherein the plurality of openings (114) are provided on an elevated head (116).
9. The device (100) as claimed in claim 1, wherein the encapsulation (102) includes a cooling circuit (110) immersed in the volume along with the phase changing material (PCM), the cooling circuit (110) being configured for charging or discharging of the phase changing material (PCM) based on a thermal energy exchange.
10. The device (100) as claimed in claim 9, wherein the cooling circuit (110) is a coolant tube defining an inlet (110a) and an outlet (110b) extending from at least one of the plurality of small faces (108).
11. The device (100) as claimed in claim 9, wherein the cooling circuit (110) is inserted in the encapsulation (102) through a cap structure (117), and wherein the cap structure (117) accommodates the inlet (110a) and the outlet (110b).
, Description:TECHNICAL FIELD
[0001] The present disclosure relates to the field of refrigeration, and more particularly to a polymer based thermal energy storage and heat transfer device provided with a phase changing material (PCM).

BACKGROUND
[0002] The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] A number of portable cooling or refrigeration devices exist in the market. The devices generally include a chemical for providing necessary cooling effect. However, there are several challenges faced by users of existing portable refrigeration devices. For example, the existing solutions have not been able to achieve a high surface to volume ratio while using a polymer instead of stainless steel as their material of encapsulation. Polymer based thermal energy storage devices offered in the market do not offer active cooling along with a high surface to volume ratio.
[0004] There is therefore a need in the art to provide a solution that overcomes the above-mentioned and other limitations of the existing solutions and utilize techniques, which are robust, accurate, fast, efficient, cost effective and simple.

SUMMARY
[0005] The present disclosure relates to the field of refrigeration, and more particularly to a polymer based thermal energy storage and heat transfer device provided with a phase changing material (PCM).
[0006] An aspect of the present disclosure relates to a thermal energy storage and heat transfer device that includes a monolithic encapsulation enclosing a volume. The encapsulation includes a first flexible large face; a second flexible large face facing the first large face; a plurality of small faces coupled with the first flexible large face and the second flexible large face; and a phase changing material (PCM) enclosed within the encapsulation (102), the phase changing material (PCM) is charged or discharged based upon a thermal energy exchange, wherein the first large face and the second large face curve towards each other during discharge phase of the phase changing material (PCM), and wherein the first large face and the second large face curve away from each other during a charge phase of the phase changing material (PCM).
[0007] In an aspect, the discharged phase of the phase changing material (PCM) is a liquid phase, and charged phase of the phase changing material (PCM) is a solid phase.
[0008] In an aspect, the device is a polymer based device.
[0009] In an aspect, the encapsulation includes a plurality of ribs or stiffeners.
[00010] In an aspect, the volume of the encapsulation increases upon solidification of the phase changing material (PCM).
[00011] In an aspect, the encapsulation attains shape of a regular cuboid upon solidification of the phase changing material (PCM).
[00012] In an aspect, at least one of the pluralities of small faces includes a plurality of openings, the openings being configured for any or a combination of replenishment of the phase changing material (PCM), escapement of air.
[00013] In an aspect, the pluralities of openings are provided on an elevated head.
[00014] In an aspect, the encapsulation includes a cooling circuit immersed in the volume along with the phase changing material (PCM), the cooling circuit being configured for charging or discharging of the phase changing material (PCM) based on a thermal energy exchange.
[00015] In an aspect, the cooling circuit is a coolant tube defining an inlet and an outlet extending from at least one of the plurality of small faces.
[00016] In an aspect, the cooling circuit is inserted in the encapsulation through a cap structure, the cap structure being configured to accommodate the inlet and the outlet.
[00017] In an aspect, the cuboidal encapsulation includes a plurality of dimple structures permitting holding of the cooling circuit.

BRIEF DESCRIPTION OF THE DRAWINGS
[00018] In the figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
[00019] FIGS. 1A-1F illustrates different views of a polymer based thermal energy storage and heat transfer device 100 in accordance with an embodiment of the present disclosure.
[00020] FIG. 2 illustrates a sectional view of the polymer based thermal energy storage and heat transfer device 100 of FIG. 1A in accordance with an embodiment of the present disclosure.
[00021] FIGS. 3A-3B illustrates different views of the polymer based thermal energy storage and heat transfer device 100 in accordance with an embodiment of the present disclosure.
[00022] FIGS. 4A-4C illustrates different views of the polymer based thermal energy storage and heat transfer device 100 in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[00023] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[00024] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
[00025] Embodiments of the present invention include various steps, which will be described below.
[00026] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[00027] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[00028] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
[00029] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[00030] All methods described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[00031] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[00032] The present disclosure relates to the field of refrigeration, and more particularly to a polymer based thermal energy storage and heat transfer device provided with a phase changing material (PCM).
[00033] An aspect of the present disclosure relates to a thermal energy storage and heat transfer device (100) includes a monolithic encapsulation (102) enclosing a volume. The encapsulation (102) includes a first flexible large face (104); a second flexible large face (106) facing the first large face (104); a plurality of small faces (108) coupled with the first flexible large face (104) and the second flexible large face (106); and a phase changing material (PCM) enclosed within the encapsulation (102), the phase changing material (PCM) is charged or discharged based upon a thermal energy exchange, wherein the first large face (104) and the second large face (106) curve towards each other during discharge phase of the phase changing material (PCM), and wherein the first large face (104) and the second large face (106) curve away from each other during a charge phase of the phase changing material (PCM).
[00034] In an aspect, the discharged phase of the phase changing material (PCM) is a liquid phase, and charged phase of the phase changing material (PCM) is a solid phase.
[00035] In an aspect, the device is a polymer based device.
[00036] In an aspect, the encapsulation (102) includes a plurality of ribs or stiffeners (112).
[00037] In an aspect, the volume of the encapsulation (102) increases upon solidification of the phase changing material (PCM).
[00038] In an aspect, the encapsulation (102) attains shape of a regular cuboid upon solidification of the phase changing material (PCM).
[00039] In an aspect, at least one of the plurality of small faces (108) includes a plurality of openings (114), the openings being configured for any or a combination of replenishment of the phase changing material (PCM), escapement of air.
[00040] In an aspect, the plurality of openings (114) are provided on an elevated head (116).
[00041] In an aspect, the encapsulation (102) includes a cooling circuit (110) immersed in the volume along with the phase changing material (PCM), the cooling circuit (110) being configured for charging or discharging of the phase changing material (PCM) based on a thermal energy exchange.
[00042] In an aspect, the cooling circuit (110) is a coolant tube defining an inlet (110a) and an outlet (110b) extending from at least one of the plurality of small faces (108).
[00043] In an aspect, the cooling circuit (110) is inserted in the encapsulation (102) through a cap structure (117), the cap structure (117) being configured to accommodate the inlet (110a) and the outlet (110b).
[00044] In an aspect, the encapsulation (102) includes a plurality of dimple structures (118) permitting holding of the cooling circuit (110).
[00045] FIGS. 1A-1F illustrates different views of a polymer based thermal energy storage and heat transfer device 100 in accordance with an embodiment of the present disclosure. In an embodiment, the thermal energy storage and heat transfer device 100 is a portable refrigeration device configured to be used with products or persons requiring a cool or low temperature. For example, the device 100 may be used with vegetables, medicines, beverages, or as cold packs for athletes, patients, etc. The device 100 may also be used to provide comfort cooling of air, providing thermal inertia to avoid temperature fluctuation for process control.
[00046] FIG. 2 illustrates a sectional view of the polymer based thermal energy storage and heat transfer device 100 of FIG. 1A in accordance with an embodiment of the present disclosure.
[00047] In an embodiment, the polymer used for manufacturing the thermal energy storage and heat transfer device 100 is high density polyethylene (HDPE). HDPE is chemically inert to brine, food grade, not attacked by (chemically reacts with) strong acids or strong bases and is resistant to gentle oxidants and reducing agents. HDPE provides necessary tensile strength, surface hardness, flexibility and durability for long term recurring usage. Such characteristics allow the device 100 to be utilized in multiple environments like medicines, chemicals, vegetables, etc.
[00048] In an embodiment, the device 100 includes an encapsulation 102 defining a volume. In an embodiment, the encapsulation 102 is cuboidal in shape. In another example, the encapsulation 102 may include any regular or irregular geometrical shape. The cuboidal encapsulation 102 includes a first flexible large face 104; a second flexible large face 106 facing the first large face 104; a plurality of small faces 108 coupled with the first flexible large face 104 and the second flexible large face 106 to achieve a monolithic structure enclosing the volume. In an example, the cuboidal outline shape provides high aspect ratio to maintain maximum possible volume to surface ratio. In an example, Ratio of dimension of the cuboidal encapsulation (102) may be 23.8:1:12.8. The monolithic structure of the encapsulation 102 has minimum sealing points, and is therefore leak proof.
[00049] In an embodiment, the first flexible large face 104 and the second flexible large face 106 are concave shaped, and curve towards each other. Further, the cuboidal encapsulation 102 is configured to hold a phase changing material (PCM) inside its volume. In an embodiment, the phase changing material (PCM) is configured to be charged or discharged based upon a thermal energy exchange. In an embodiment, the first flexible large face 104 and the second flexible large face 106 curves towards each other based upon a discharged phase of the phase changing material (PCM). In an example, the discharged phase of the phase changing material (PCM) is a liquid phase. The inward curve of the flexible faces (104, 106) allows for increase in volume during solidification of phase change material, as during a phase change / solidification of the phase changing material (PCM), an internal pressure will be developed that will push the flexible faces (104, 106) outwards. In an embodiment, the first flexible large face (104) and the second flexible large face (106) curve away from each other based upon a charged phase of the phase changing material (PCM), wherein the charged phase of the phase changing material (PCM) is a solid phase. In an example, the volume of the cuboidal encapsulation 102 increases upon solidification of the phase changing material (PCM), wherein the encapsulation 102 attains shape of a regular cuboid upon solidification of the phase changing material PCM. Post solidification, shape of the encapsulation 102 will not exceed a cuboid with planar faces (104, 106).
[00050] In an embodiment, the charging of the phase changing material (PCM) of the device 100 may be achieved by placing the device 100 in a cold environment like a refrigerator or freezer or any other cooling device. The phase changing material (PCM) would undergo a change of phase from a liquid state to a solid state upon receiving the cooling from the refrigerator or freezer. Upon being charged, the device 100 may be used as a portable cooling device, and can be used for multiple applications. Thus, the device 100 may be used as a standalone thermal energy storage panel with passive charging and passive discharging. The device 100 is capable of being charged without applying direct power, and can be used a cooling source when no electricity is available.
[00051] In an embodiment, the cuboidal encapsulation 102 includes a plurality of ribs or stiffeners 112. In an example, the ribs or stiffeners 112 provides necessary strength and flexibility. Further, the ribs 112 are hollow and allows the encapsulation 102 to sustain the internal pressure, for example 5 psig, during the change of phase from liquid to solid due to expansion in volume of the phase changing material (PCM).
[00052] In an embodiment, at least one of the plurality of small faces 108 includes a plurality of openings 114, the openings 114 being configured for any or a combination of replenishment of the phase changing material (PCM), and escapement of air present in the encapsulation. In an example, the openings 114 may be provided on an elevated head 116, and may be used for filling of uncharged phase change material (PCM), where one opening 104 is being used for filling while the other facilitates an escape / vent for air and permits smooth flow at its highest mass flux capacity, hence a quicker assembly process. The elevated head 116 is to eliminate and/or reduce the air trapped during filling of phase changing material (PCM). Escapement of air from the device 100 allows for high thermal energy exchange and increased effectiveness.
[00053] In another embodiment, the cuboidal encapsulation 102 may further include a cooling circuit 110 (Refer FIGS. 3A-3B) immersed in the volume along with the phase changing material (PCM). The cooling circuit 110 provides an active charging of the phase changing material (PCM). In an example, a low temperature coolant or liquid may be allowed to flow through the cooling circuit 110 such that a thermal energy exchange occurs between the cooling circuit and the phase changing material (PCM). The thermal energy exchange provides for charging of the phase changing material (PCM). In another example, a high temperature coolant may be allowed to flow through the cooling circuit 110 for discharging the phase changing material (PCM) from a solid state to a liquid state. In an embodiment, the cooling circuit 110 is a coolant tube defining an inlet 110a and an outlet 110b extending from at least one of the plurality of small faces 108. Further, similar to the earlier embodiment, the first large face 104 and the second large face 106 curve away from each other upon solidification of the phase changing material (PCM), wherein the solidification of the phase changing material (PCM) depends upon thermal energy exchange between the cooling circuit 110 and the phase changing material (PCM). In an example, the volume of the cuboidal encapsulation 102 increases upon solidification of the phase changing material (PCM), wherein the encapsulation 102 attains shape of a regular cuboid upon solidification of the phase changing material (PCM). Post solidification, shape of the encapsulation 102 will not exceed a cuboid with planar faces (104, 106).
[00054] Referring to FIGS. 3A-B and 4A-C, the device 100 further provides that the plurality of openings 114 are provided on a cap structure 117, the cap structure 117 being sealing secured to the cuboidal encapsulation 102, for inlet of PCM and an escape valve for excess air. The cap structure 116 may also be provided with the elevated head 116 to eliminate and/or reduce the air trapped during filling of PCM.
[00055] Further, in an embodiment, the cooling circuit 110 is inserted in the encapsulation 102 through the cap structure 117, the cap structure 117 accommodates the inlet 110a and the outlet 110b. In an example, the cap structure 117 may be welded or snap-fitted with a gasket on to the encapsulation 102 to ensure a leak proof environment.
[00056] Further in an embodiment, the cuboidal encapsulation 102 includes a plurality of dimple structures 118 permitting holding of the cooling circuit 110. The dimple structures 118 may include a spherical or hemi-spherical geometry. In an example, the dimple structures 118 may be provided on the first flexible large face 104 and the second flexible large face 106 to locate the cooling circuit 110 inside the encapsulation 102.
[00057] The device 100 solves the physical problem of structural integrity of using HDPE as an encapsulation for latent heat storage. With the use of hollow ribs and concave shape the obstacle of expanding encapsulation at the time of solidifying of phase change material is overcome while also staying inert to the stored material and keeping an optimal surface to volume ratio for maximum efficiency. Cuboidal shape with minimal possible thickness ensures optimal heat transfer efficiency. The design shape and structure allow for active charging via cooling coils while maintaining a leak proof and airtight constitution.
[00058] As used herein, and unless the context dictates otherwise, the term "coupled to" is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms "coupled to" and "coupled with" are used synonymously. Within the context of this document terms "coupled to" and "coupled with" are also used euphemistically to mean “communicatively coupled with” over a network, where two or more devices are able to exchange data with each other over the network, possibly via one or more intermediary device.
[00059] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C …. and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
[00060] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable people having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES
[00061] The device 100 may be used for air cooling, when charged using cooling coils inside the encapsulation, or an external cooling source.
[00062] The device 100 may be used for cooling of secondary refrigerant in circulation using the coils inside the encapsulation.
[00063] The device 100 may be used as a standalone thermal energy storage panel with passive charging and passive discharging.
[00064] The device 100 may be used for providing cooling when no power source for cooling is present - can be used in areas with erratic electricity, for providing backup in renewable energy (solar and wind) powered devices, for transport of temperature sensitive commodities.
[00065] Use of monolithic cuboidal encapsulation with hollow ribs made of plastic polymer overcomes the challenge of providing strength and robustness enough to overcome the internal pressures generated during solidification of the phase change material, while significantly minimizing the thickness of the encapsulation to improve heat transfer efficiency.
[00066] The device 100 provides encapsulation that permits 100% volume filling with phase change material and is leak-proof and sealed airtight.
[00067] The device 100 includes concave faces of the walls with highest surface area permits change in internal volume without compromising the strength and robustness.
[00068] Use of cuboidal shape provides maximized surface to volume ratio.
[00069] The device 100 is cost effective and easy to implement.