US20240263844A1

US20240263844A1 - Heat exchangers, systems and methods of using the same

Info

Publication number: US20240263844A1
Application number: US18/410,702
Authority: US
Inventors: Pranay Asai; Pratik Asai; John McLennan; Milind Deo
Original assignee: University of Utah Research Foundation Inc
Current assignee: University of Utah Research Foundation Inc
Priority date: 2023-02-03
Filing date: 2024-01-11
Publication date: 2024-08-08

Abstract

An example heat exchanger includes an outer housing defining an outer chamber. The heat exchanger also includes an inner housing disposed in the outer chamber. The inner housing defines an inner chamber and at least one opening allowing the outer and inner chambers to be in fluid communication with each other. The heat exchanger further includes a first connector in fluid communication with the outer chamber and a second connector in fluid communication with the inner chamber. The first and second connectors are configured to allow a fluid to flow into or out of the heat exchanger. In some embodiments, the heat exchanger may also at least one of exhibit a generally conical shape, a truncated generally conical shape, or a generally cylindrical shape; include at least one helical structure disposed in the outer chamber; or exhibit a modular design.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent Application No. 63/483,112 filed on Feb. 3, 2023, the disclosure of which is incorporated herein, in its entirety, by this reference.

BACKGROUND

The temperature of the ground a certain distance below the surface maintains a substantially constant temperature year round. Ground source, geoexchange, borehole thermal energy systems and similar nomenclature describe heat exchangers disposed in the ground, configured to leverage the substantially constant temperature of the ground to heat or cool individual buildings or complexes. These heat exchangers may extract thermal energy from the ground, use the extracted thermal energy to enable heating a home during winter, and may dispose thermal energy extracted from the home into the ground during summer.

SUMMARY

Embodiments are directed to heat exchangers, systems including the same, and methods of using and manufacturing the same. In an embodiment, a heat exchanger is disclosed. The heat exchanger includes an outer housing defining an outer chamber and an inner housing disposed in the outer chamber. The inner housing defining an inner chamber. The inner chamber is in fluid communication with the outer chamber via at least one opening at least partially defined by the inner housing. The heat exchanger also includes a first connector in fluid communication with the outer chamber and a second connector in fluid communication with the inner chamber. At least one of the outer housing exhibits a generally conical shape or a truncated generally conical shape or the heat exchanger further comprises at least one helical structure disposed in the outer chamber. The at least one helical structure extending at least substantially between the outer housing and the inner housing. A pitch of at least a portion of the at least one helical structure varies along at least a portion of a length of the outer housing.
In an embodiment, a system is disclosed. The system includes at least one heat exchanger. The at least one heat exchanger includes an outer housing defining an outer chamber and an inner housing disposed in the outer chamber. The inner housing defining an inner chamber. The inner chamber is in fluid communication with the outer chamber via at least one opening at least partially defined by the inner housing. The at least one heat exchanger also includes a first connector in fluid communication with the outer chamber and a second connector in fluid communication with the inner chamber. At least one of the outer housing exhibits a generally conical shape or a truncated generally conical shape or the at least one heat exchanger further comprises at least one helical structure disposed in the outer chamber. The at least one helical structure extending at least substantially between the outer housing and the inner housing. A pitch of at least a portion of the at least one helical structure varies along at least a portion of a length of the outer housing. The system also includes a pump and at least one pipe fluidly connecting the at least one heat exchanger and the pump together. The pump is configured to flow a fluid through the at least one pipe and the at least one heat exchanger.
In an embodiment, a method of using a heat exchanger is disclosed. The method includes providing the at least one heat exchanger that is disposed in an outer environment. The at least one heat exchanger includes an outer housing defining an outer chamber and an inner housing disposed in the outer chamber. The inner housing defines an inner chamber. The inner chamber is in fluid communication with the outer chamber via at least one opening at least partially defined by the inner housing. The at least one heat exchanger also includes a first connector in fluid communication with the outer chamber and a second connector in fluid communication with the inner chamber. At least one of the outer housing exhibits a generally conical shape or a truncated generally conical shape or the at least one heat exchanger further comprises at least one helical structure disposed in the outer chamber. The at least one helical structure extending at least substantially between the outer housing and the inner housing. A pitch of at least a portion of the at least one helical structure varies along at least a portion of a length of the outer housing. The method also includes flowing a fluid through the outer chamber to transfer thermal energy between the outer environment and the fluid and flowing the fluid through the inner chamber.
Features from any of the disclosed embodiments may be used in combination with one another, without limitation. In addition, other features and advantages of the present disclosure will become apparent to those of ordinary skill in the art through consideration of the following detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate several embodiments of the present disclosure, wherein identical reference numerals refer to identical or similar elements or features in different views or embodiments shown in the drawings.

FIG. 1A is an isometric view of a heat exchanger, according to an embodiment.

FIG. 1B is a cross-sectional view of the heat exchanger taken along plane 1B-1B.

FIG. 2 is a cross-sectional view of a heat exchanger that includes an outer housing exhibiting a different shape than the inner housing, according to an embodiment.

FIG. 3A is an isometric view of a heat exchanger including an outer housing exhibiting a generally cylindrical shape, according to an embodiment.

FIG. 3B is a cross-sectional view of the heat exchanger taken along plane 3B-3B, according to an embodiment.

FIG. 4A is an isometric view of a heat exchanger including an outer housing exhibiting a truncated generally conical shape, according to an embodiment.

FIG. 4B is a cross-sectional view of the heat exchanger taken along plane 4B-4B, according to an embodiment.

FIG. 5A is a cross-sectional view of a heat exchanger, according to an embodiment.

FIG. 5B is an enlarged cross-sectional view of a portion of the heat exchanger taken from the circle 5B shown in FIG. 5A.

FIG. 6 is a cross-sectional view of a heat exchanger including a helical structure, according to an embodiment.

FIG. 7 is an isometric view of a heat exchanger including one or more surface features, according to an embodiment.

FIG. 8 is a cross-sectional view of a portion of a wall of an outer housing, according to an embodiment.

FIG. 9 is a cross-sectional view of a heat exchanger, according to an embodiment.

FIG. 10 is a cross-sectional view of a heat exchanger including an insulating material, according to an embodiment.

FIG. 11A is an isometric view of a heat exchanger exhibiting a modular design, according to an embodiment.

FIG. 11B is a cross-sectional view of the heat exchanger taken along plane 11B-11B.

FIG. 11C is an exploded cross-sectional view of the heat exchanger.

FIG. 12 is a diagram of a geothermal system that may include any of the heat exchangers disclosed herein, according to an embodiment.

DETAILED DESCRIPTION

Embodiments are directed to heat exchangers, systems including the same, and methods of using and manufacturing the same. An example heat exchanger includes an outer housing defining an outer chamber. The heat exchanger also includes an inner housing disposed in the outer chamber. The inner housing defines an inner chamber and at least one opening allowing the outer and inner chambers to be in fluid communication with each other. The heat exchanger further includes a first connector in fluid communication with the outer chamber and a second connector in fluid communication with the inner chamber. The first and second connectors are configured to allow a fluid to flow into or out of the heat exchanger. In some embodiments, the heat exchanger may also at least one of exhibit a generally conical shape, a truncated generally conical shape, or a generally cylindrical shape; include at least one helical structure disposed in the outer chamber; or exhibit a modular design, as discussed in more detail below. It is noted that the shape of the heat exchanger may refer to the shape of at least one of the outer housing (e.g., the shape of the outer surface and/or inner surface of the outer housing) or the inner housing (e.g., the shape of the outer surface and/or inner surface of the inner housing).
The heat exchanger is disposed in an outer environment (e.g., ground). During use, fluid flows into the heat exchanger. In an example, the fluid flows into the heat exchanger via the first connector and out of the heat exchanger via the second connector. In such an example, the fluid flows into the outer chamber via the first connector, through the outer chamber, from the outer chamber into the inner chamber via the opening, through the inner chamber, and out of the inner chamber via the second connector. In an example, the fluid flows into the heat exchanger via the second connector and out of the heat exchanger via the first connector. In such an example, the fluid flows into the inner chamber via the first connector, through the inner chamber, from the inner chamber into the outer chamber via the opening, through the outer chamber, and out of the outer chamber via the first connector. Regardless of the direction of flow of the fluid through the heat exchanger, the heat exchanger is configured to transfer thermal energy between the outer environment and at least the fluid flowing through the outer chamber.
The outer environment may include the ground (e.g., earth). The ground exhibits a substantially consistent temperature year-round below a certain depth below the surface. The heat exchanger may leverage the substantially consistent temperature of the ground to regulate a temperature of a building (e.g., residential building, commercial building, etc.). In an example, the building may exhibit a temperature that is higher than desired, such as during summertime. In such an example, some of the thermal energy of the building may be transferred to the fluid. In other words, the fluid is heated. The heated fluid may flow into the heat exchanger. The thermal energy from the heated fluid may be transferred to the ground thereby cooling the heated fluid. The cooled fluid may then be flowed back into the building. The combination of transferring thermal energy from the building to the fluid and flowing a cooled fluid into the building effectively cools the building. In an example, the building may exhibit a temperature that is lower than desired, such as during wintertime. In such an example, some of the thermal energy of the fluid may be transferred to the building. In other words, the fluid is cooled. The cooled fluid may flow into the heat exchanger. The thermal energy from the ground may be transferred to the fluid thereby heating the fluid. The heated fluid may then be flowed back into the building. The combination of transferring thermal energy from the fluid to the building and flowing a heated fluid into the building effectively heats the building.
In an embodiment, a heat pump may be used to facilitate the heating and cooling of the building using the fluid. For example, the fluid may exhibit a temperature of that corresponds to the average temperature of the ground (e.g., about 14° C.). During the winter, a heat pump fluid of the heat pump may receive thermal energy from the fluid which causes the fluid to heat the heat pump fluid and evaporate. The heat pump may then compress the evaporated heat pump fluid to increase the pressure of the fluid. This process further increases the temperature of the heat pump fluid (e.g., to a temperature greater than room temperature). The heat pump may then use the increased temperature of the heat pump fluid to heat the building. The heat pump may then cool the heat pump fluid by decompressing the heat pump fluid. The cooled heat pump fluid may then cool the fluid before the fluid returns to the heat exchangers allowing this process to continue in a loop. The opposite process may occur during the summer thereby allowing the heat pump to cool the building.
Although the heat exchangers disclosed herein are mainly discussed as regulating the temperature of buildings, it is noted that the heat exchangers disclosed herein may be used in other applications. In an example, the heat exchanger may be disposed in a heated waste stream (i.e., the heated waste stream is the outer environment). In such an example, a fluid flowing through the heat exchangers may be heated thereby recouping thermal energy from the heated waste stream. In an example, the heat exchanger may be disposed in a cooled fluid that needs a temperature thereof increased (i.e., the cooled fluid is the outer environment). In such an example, a heated fluid may flow through the heat exchanger thereby heating the cooled fluid.
The heat exchangers disclosed herein are an improvement over conventional heat exchangers. An example of a conventional heat exchanger includes a conventional heat exchanger exhibiting a length greater than 30 m, such as greater than 60 m. Installing this conventional heat exchanger can require large drilling equipment to dispose the conventional heat exchanger into the ground, thereby making installation of the heat exchanger complicated and expensive. Repair of such heat exchangers is also impractical due to the depth at which portions of the heat exchangers are buried. Another example of a conventional heat exchanger includes a heat exchanger that consists of a large network of buried pipes. This large network of pipes can require digging a large network of deep trenches to dispose the heat exchangers in the ground. Digging the large network of deep trenches can be complicated and expensive.
The heat exchangers disclosed herein are an improvement over such conventional heat exchangers. For example, the heat exchanger may exhibit a maximum length of about 3 m or less, such as about 2 m or less or about 1 m to about 2 m. Such heat exchangers may be disposed in vertical holes that may be made using equipment that may be used by an individual (e.g., handheld augers) and without needing to dig a large network of deep trenches. As such, the heat exchangers disclosed herein may be installed much quicker and easier than the conventional heat exchangers without needing to dig up or otherwise damage large areas of land. Further, the smaller size of the heat exchangers disclosed herein makes repairing the heat exchanger much more manageable than the conventional heat exchangers since smaller holes may be dug to access and/or remove the heat exchanger from the ground than conventional heat exchangers.
The heat exchangers may include other improvements, as will be discussed in more detail below. For example, the heat exchangers disclosed herein may include surface features, exhibit shapes, etc. that promote thermal energy transfer, minimize inefficiencies (e.g., minimize dead spaces), etc.
FIG. 1A is an isometric view of a heat exchanger 100, according to an embodiment. FIG. 1B is a cross-sectional view of the heat exchanger 100 taken along plane 1B-1B. The heat exchanger 100 includes an outer housing 102 defining an outer chamber 104. The heat exchanger 100 also includes an inner housing 106 disposed in the outer chamber 104. The inner housing 106 defines an inner chamber 108 and an opening 110 that allows fluids to flow between the outer chamber 104 and the inner chamber 108.
The outer housing 102 includes a top region 112 and a bottom region 114. Generally, the top region 112 includes a region (e.g., surface) of the outer housing 102 that is closest to the surface of the ground, upstream of a waste stream, and/or where the fluid flows into and/or out of the outer housing 102. The bottom region 114 includes a region (e.g., surface or apex) of the outer housing 102 that is opposite the top region 112. For example, the bottom region 114 may include a region of the outer housing 102 that is furthest from the surface of the ground. In an embodiment, as shown, the heat exchanger 100 is formed of a single piece or a plurality of pieces that are permanently attached together (e.g., welded). In an embodiment, the heat exchanger 100 includes a plurality of pieces that are reversibly attached together (e.g., designed to be detached from each other without damaging the heat exchanger 100). In such an embodiment, the plurality of pieces of the heat exchanger 100 may include a tongue and groove configuration, a snap fit configuration, or exhibit a modular design, as shown in FIG. 11 .
The outer housing 102 may be formed from any suitable material. In an embodiment, the outer housing 102 may be formed from a non-corrosive material, such as stainless steel, aluminum, a polymeric material (e.g., polylactic acid, polyethylene terephthalate, polycarbonate, polyvinyl chloride, etc.), or a material (e.g., carbon steel) coated with a corrosive resistant material. The outer housing 102 may be formed from a corrosive resistant material because the outer housing 102 may be in contact with corrosive materials, such as the ground and/or the fluid (e.g., water). Allowing the outer housing 102 to corrode effectively decreases the lifespan of the heat exchanger 100. Maximizing the lifespan of the heat exchanger may be desirable because deployment, replacement, and repairing of the heat exchanger 100 may be expensive since, for example, the heat exchanger 100 may be buried. In an embodiment, the outer housing 102 may be formed from a metal, such as stainless steel or aluminum. Generally, metals exhibit a thermal conductivity that is greater than some other materials, such as polymers. As such, forming the outer housing 102 from a metallic material may be more efficient transferring thermal energy between the fluid in the outer chamber 104 and the outer environment than if the outer housing was formed from another material, such as a polymer. Forming the outer housing 102 from a metallic material may also increase the strength of the heat exchanger 100 than if the outer housing 102 was formed from other materials. The increased strength of the metallic outer housing 102 may allow the outer housing 102 to have thinner walls, which will increase thermal energy transfer between the outer environment and the fluid and increase the volume of the outer chamber 104 which, in turn, will increase the residence time of the fluids in the outer chamber 104. It is noted that at least some conventional heat exchangers are not formed from metal since the decreased flexibility of the metal makes installation of the heat exchangers more difficult. In an embodiment, the heat exchanger 100 is formed from a 3D printable material, such as polylactic acid, polyethylene terephthalate, polycarbonate, a metal, etc.
The outer housing 102 includes at least one outer surface 103 and at least one inner surface 105 defining the outer chamber 104. During use, the outer surface 103 may contact the outer environment. The outer housing 102 exhibits a thickness t₁measured between the outer surface 103 and the inner surface 105. The thickness t₁may be about 0.5 mm or greater, about 1 mm or greater, about 1.5 mm or greater, about 2 mm or greater, about 2.5 mm or greater, about 3 mm or greater, about 3.5 mm or greater, about 4 mm or greater, about 5 mm or greater, about 6 mm or greater, about 7 mm or greater, about 8 mm or greater, about 10 mm or greater, or in ranges of about 0.5 mm to about 1.5 mm, about 1 mm to about 2 mm, about 1.5 mm to about 2.5 mm, about 2 mm to about 3 mm, about 2.5 mm to about 3.5 mm, about 3 mm to about 4 mm, about 3.5 mm to about 5 mm, about 4 mm to about 6 mm, about 5 mm to about 7 mm, about 6 mm to about 8 mm, or about 7 mm to about 10 mm. The thickness t₁of the outer housing 102 may be selected based on a number of factors. In an example, the thickness t₁may be selected based on the material of the outer housing 102 and, in particular, the thermal conductivity and strength of the material. For instance, the thickness t₁may be decreased as the strength of the material is increased and/or the thermal conductivity of material is decreased. In an example, the thickness t₁may be selected based on the method used to dispose the heat exchanger 100 into the outer environment (e.g., is the heat exchanger 100 buried in a hole or hammered into a hole), the expected loads applied to the heat exchanger 100, or the expected thermal shock experienced by the outer housing 102.
In an embodiment, the thickness t₁of at least a portion of the outer housing 102 may be substantially uniform which may facilitate manufacturing of the outer housing 102. For example, the substantially uniform thickness t₁of the outer housing 102 may allow at least a portion of the outer housing 102 to be formed from a sheet (e.g., sheet of metal) that is bent. In an embodiment, the thickness t₁of at least a portion of the outer housing 102 may exhibit a variable thickness t₁. For example, the temperature of the ground adjacent to the outer housing 102 may vary. The variable thickness t₁of the outer housing 102 may be used to leverage the variable temperature of the ground. For instance, the thickness t₁of the outer housing 102 at or near the bottom region 114 may be thinner than the thickness t₁of the outer housing 102 at or near the top region 112. The thinner portions of the outer housing 102 at or near the bottom region 114 may improve thermal energy transfer at or near the bottom region 114 where such thermal energy transfer may be most beneficial. The thicker portions of the outer housing 104 at or near the top region 112 may minimize thermal energy transfer (e.g., act more like an insulating material) which, in some applications, may be beneficial.
The outer housing 102 may exhibit a generally conical shape. For example, the outer housing 102 may exhibit the generally conical shape when the outer surface 103 exhibits a generally conical shape. The conical shape of the outer housing 102 may be oriented such that an apex of the conical shape forms the bottom region 114 of the outer housing 102. The conical shape of the outer housing 102 may facilitate inserting the heat exchanger 100 into the outer environment, for example, by pounding the heat exchanger 100 directly into the outer environment or into a hole that is not deep enough and/or wide enough to accommodate the heat exchanger 100. The conical shape of the outer housing 102 also allows the heat exchanger 100 to exhibit a surface area to volume ratio that is greater than if the outer housing 102 exhibited a generally cylindrical shape or some other shapes. The larger surface area to volume ratio of the conical shape improves the transfer of thermal energy between the outer environment and the fluid in the outer chamber 104. In other words, the conical shape of the outer housing 102 causes the heat exchanger 100 to exhibit several benefits. However, the conical shape of the outer housing 102 also may cause some issues. For example, the conical shape of the outer housing 102 may decrease the residence time of the fluid in the heat exchanger 100 (i.e., the time that the fluid is present in the heat exchanger 100). The temperature gradient between the fluid entering and exiting the heat exchanger 100 depends, in part, on the residence time of the fluid in the heat exchanger 100. As such, a system including the heat exchanger 100 may require more heat exchangers for the fluid to exhibit a large temperature gradient even though the heat exchanger 100 does improve thermal energy transfer between the fluid and the outer environment. Also, the conical shape of the outer housing 102 may form a dead spot at or near the bottom region 114 (e.g., the apex). A dead spot is a location where little to no fluid movement occurs during operation. The dead spot at or near the bottom region 114 decreases the efficiency of the heat exchanger 100 since thermal energy transferred between the outer environment and the fluid in the dead spot is minimal. Due to the benefits and issues associated with the outer housing 102 exhibiting a conical shape, the heat exchanger 100 may be more beneficial when used in certain applications (e.g., in large areas that can accommodate a large number of heat exchangers) than in other applications (e.g., in small areas that can only accommodate a few heat exchangers).
The outer housing 102 may exhibit a length L measured along a longitudinal axis of the heat exchanger 100 (e.g., from the top region 112 to the bottom region 114). In an embodiment, the length L of the outer housing 102 may be about 5 m or less, more preferably about 3 m or less, or more preferably about 2 m or less (i.e., the general height of a man or less) since the outer housing 102 exhibiting such lengths may be easier to install in the ground than if the length L of the outer housing 102 was greater than 6 m. For example, the outer housing 102 may exhibit a length L of about 0.5 m to about 1 m, about 0.75 m to about 1.25 m, about 1 m to about 1.5 m, about 1.25 m to about 1.75 m, about 1.5 m to about 2 m, about 1.75 m to about 2.25 m, about 2 m to about 2.5 m, about 2.25 m to about 2.75 m, about 2.5 m to about 3 m, about 2.75 m to about 3.5 m, about 3 m to about 4 m, about 3.5 m to about 4.5 m, or about 4 m to about 5 m. It is noted that the outer housing 102 may exhibit a relatively large length L that is greater than 5 m, such as about 7.5 m or greater, about 10 m or greater, about 15 m or greater, about 20 m or greater, about 30 m or greater, about 40 m or greater, about 50 m or greater, about 75 m or greater, about 100 m or greater, about 150 m or greater, or in ranges of about 5 m to about 10 m, about 7.5 m to about 15 m, about 10 m to about 20 m, about 15 m to about 30 m, about 20 m to about 40 m, about 30 m to about 50 m, about 40 m to about 75 m, about 50 m to about 100 m, or about 75 m to about 150 m. It is noted that the modular heat exchanger 1100 of FIG. 11 may facilitate installation of heat exchangers exhibiting the relatively large lengths discussed above. The length L of the outer housing 102 may be selected based on, for example, at least one of the desired volume of the outer chamber 104 and the expected size of the hole in which the heat exchanger 100 is disposed.
The outer housing 102 exhibits a maximum lateral dimension D (e.g., diameter). The maximum lateral dimension D may be selected to be about 5 cm or greater, about 10 cm or greater, about 15 cm or greater, about 20 cm or greater, about 25 cm or greater, about 30 cm or greater, about 35 cm or greater, about 40 cm or greater, about 50 cm or greater, about 60 cm or greater, about 70 cm or greater, about 80 cm or greater, about 1 m or greater, about 1.25 m or greater, about 1.5 m or greater, about 2 m or greater, or in ranges of about 5 cm to about 15 cm, about 10 cm to about 20 cm, about 15 cm to about 25 cm, about 20 cm to about 30 cm, about 25 cm to about 35 cm, about 30 cm to about 40 cm, about 35 cm to about 50 cm, about 40 cm to about 60 cm, about 50 cm to about 70 cm, about 60 cm to about 80 cm, about 70 cm to about 1 m, about 80 cm to about 1.25 m, about 1 m to about 1.5 m, or about 1.25 m to about 2 m. The maximum lateral dimension D of the outer housing 102 may be selected based on at least one of the desired volumes of the outer chamber 104, the desired surface area to volume ratio of the outer housing 102, and the expected size of the hole in which the heat exchanger 100 is disposed.
As previously discussed, the heat exchanger 100 includes an inner housing 106 disposed in the outer chamber 104. The inner housing 106 effectively divides the volume defined by the outer housing 102 between the outer chamber 104 and the inner chamber 108. The inner housing 106 forms a fluid flow path that allows the fluid to effectively flow through the heat exchanger 100 when the first and second connectors 118, 120 are located on or near the top region 112. For example, the inner housing 106 allows the fluid to flow down the outer chamber 104, through the opening 110, and up the inner chamber 108 (e.g., the inner chamber 108 is a return fluid flow path), or vice versa. The inner housing 106 extends from or near the top region 112 to or near the bottom region 114 thereby allowing the fluid to flow along substantially all of a length L of the heat exchanger 100. Allowing the fluid to flow along substantially all of the length of the heat exchanger 100 minimizes dead spots and improves the efficiency of the heat exchanger 100 (e.g., maximized thermal energy transfer between the fluid and the outer environment and the temperature gradient of the fluid entering and exiting the heat exchanger 100).
The inner housing 106 may be formed from any of the materials disclosed herein. For example, the inner housing 106 may be formed from a corrosive resistant material to maximize the lifespan of the heat exchanger 100, a metal, a 3D printable material, or any other material. In an embodiment, at least a portion of the inner housing 106 may exhibit single piece construction with at least a portion of the outer housing 102 or be otherwise permanently attached together. In such an embodiment, failure of the heat exchanger 100 caused by the inner housing 106 becoming detached from the outer housing 102 is minimized. In an embodiment, the inner housing 106 may be formed from or coated by a more insulating material than the material that forms the outer housing 102. For example, there is a temperature difference between the fluid in the outer and inner chambers 104, 108 at or near the top region 112. This temperature difference may detrimentally decrease the overall temperature gradient between the fluid entering and exiting the heat exchanger 100. Forming the inner housing 106 from an insulating material may minimize the detrimental decrease in the overall temperature gradient between the fluid entering and exiting the heat exchanger 100.
The inner housing 106 includes at least one outer surface 107 defining a portion of the outer chamber 104 and at least one inner surface 109 defining at least a portion of the inner chamber 108. The inner housing 106 may exhibit a thickness t₂measured between the outer surface 107 and the inner surface 109. The thickness t₂may be selected from any of the thickness discussed above with regards to the thickness t₁of the outer housing 102. The thickness t₂of the inner housing 106 may be the same as or different than the thickness t₁of the outer housing 104. The thickness t₂of the inner housing 106 may be selected for similar reasons as the thickness t₁of the outer housing t₁(e.g., the material, expected thermal shock, etc.). In an embodiment, the thickness t₂of the inner housing 106 may be uniform which may facilitate manufacturing of the inner housing 106, for example, from a sheet. In an embodiment, the thickness t₂of the inner housing 106 may be varied. The varied thickness t₂of the inner housing 106 may be used to control thermal energy transfer between the fluid in the outer chamber 104 and the fluid in the inner chamber 108. For instance, the thickness t₂of the inner housing 106 may be greater at or near the top region 112 and thinnest at or near the opening 110. The thicker portions of the inner housing 106 may limit thermal energy transfer between the fluid in the outer and inner chambers 104, 108 at or near the top region 112 since the temperature difference between such fluids may be greatest at or near the top region 112. Limiting the thermal energy transfer between such fluids may prevent unsatisfactory heating or cooling of the fluid exiting the heat exchanger 100.
In an embodiment, as shown, the inner housing 106 may exhibit a shape that is similar to and a size that is smaller than the outer housing 102. For example, the outer surface 107 of the inner housing 106 may exhibit a shape that is similar to and a size that is smaller than the inner surface 105 of the inner housing 102. The similar shape of the inner housing 106 may cause substantially all of the fluids in the outer chamber 108 to be positioned proximate to the outer housing 102. Positioning the fluids proximate to the outer housing 102 increases the amount of thermal energy transferring between the fluids in the outer chamber 104 and the outer environment than if the inner housing 106 exhibited another shape (e.g., a cylindrical shape). Also, the similar shape of the inner housing 106 may minimize the formation of dead spots in the outer chamber 104 than if the inner housing 106 exhibited another shape. However, the similar shape of the inner housing 106 may decrease the volume of the outer chamber 104 which, in turn, decreases the residence time of the fluids in the outer chamber 104. It is noted that the quantity of thermal energy transferred between the fluid and the outer environment depends, in part, on the residence time of the fluids in the outer chamber 104. Thus, decreasing the residence time of the fluids in the outer chamber 104 may decrease the quantity of thermal energy transfer between the fluid and the outer environment. In other words, the similar shape of the inner housing 106 may decrease a temperature gradient of the fluids entering and exiting the heat exchanger 100. As such, the inner housing 106 exhibiting a shape that is similar to the outer housing 102 may only be used in certain applications.
The heat exchanger 100 includes a first connector 118 and a second connector 120. The first connector 118 is in fluid communication with the outer chamber 104 and allows the fluid to flow into or out of the outer chamber 104. The second connector 120 is in fluid communication with the inner chamber 108 and allows a fluid to flow into or out of the inner chamber 108. The first and second connectors 118, 120 are also configured to be attached to pipes using any suitable technique. Generally, the first and second connectors 118, 120 are formed at or near the top region 112 of the outer housing 102 which allows the first and second connectors 118, 120 to be located near a surface of the ground. Positioning the first and second connectors 118, 120 on or near the top region 112 decreases the depth below the surface that the pipes must extend to be connected to the first and second connectors 118, 120 which, in turn, may facilitate connecting the heat exchanger 100 to a larger system. However, it is noted that the first and second connectors 118, 120 may be formed on other portions of the heat exchanger 100, such as on the lateral surface of the outer housing 102. Although the heat exchanger 100 is illustrated as including a single first connector 118 and a single second connector 120, the heat exchanger 100 may include a plurality of first connectors 118 and/or a plurality of second connectors 120.
In an embodiment, as shown, the outer housing 102 forms the first and second connectors 118, 120. In an embodiment, not shown, the inner housing 106 may form at least one of the first connector 118 or second connector 120, such as when the inner housing 106 is distinct from the outer housing 104 and extends through the top region 112.
Not wishing to be bound by theory, it is currently believed that the heat exchanger 100 is more efficient when the first connector 118 is the input of the heat exchanger 100 and the second connector 120 is the output of the heat exchanger 100. The outer environment typically exhibits a temperature gradient between the top region 112 and the bottom region 114. The temperature of the outer environment near the top region 112 tends to be more similar to the temperature of the fluid entering the heat exchanger 100 than the temperature of the outer environment near the bottom region 114. It is currently believed that the smaller temperature difference between the fluid entering the outer chamber 104 via the first connector 118 and the temperature difference between the fluid entering the outer chamber 104 via the opening 110 results in more efficient thermal energy transfer between the outer environment and the fluid. That said, it is noted that the second connector 120 may be the input of the heat exchanger 100 and the first connector 118 may be the output. For brevity, the methods discussed below will assume that the first connector 118 is the input and the second connector 120 is the output though, as previously discussed, this can be reversed.
During use, the fluid enters the outer chamber 104 via the first connector 118. The fluid may be provided to the first connector 118 via one or more pipes (e.g., pipes 1256 shown in FIG. 12 ). The fluid may include water, water with antifreeze (e.g., to prevent freezing of the fluid), or any other suitable fluid. The fluid may flow through the outer chamber 104. Thermal energy is transferred between the fluid and the outer environment through the outer housing 104 as the fluid flows through the outer chamber 104. For example, the thermal energy may flow from the outer environment to the fluid when the outer environment is hotter than the fluid or may flow from the fluid to the outer environment when the fluid is hotter than the outer environment. The amount of thermal energy that flows between the outer environment and the fluid depends, in part, on the residence time of the fluid in the heat exchanger 100 (more particularly, the residence time of the fluid in the outer chamber 104) and the surface area to volume ratio of the heat exchanger 100 (more particular, the surface area to volume ratio of the outer housing 104).
The fluid may flow from the outer chamber 104 into the inner chamber 108 via the opening 110. The fluid may then flow through the inner chamber 108. Some thermal energy may transfer between the outer environment and the fluid flowing through the inner chamber 108. However, the thermal energy transfer between the fluid flowing through the inner chamber 108 and the outer environment may be significantly less than the thermal energy transfer between the fluid flowing through the outer chamber 104 and the outer environment due to the distance and material between the fluid flowing through the inner chamber 108 and the outer environment. In some embodiments, thermal energy transfer between the fluid flowing through the inner chamber 108 and the outer environment and/or the outer chamber 104 may be undesirable. For example, such thermal energy transfer may result in thermal energy being transferred from the fluid exiting the heat exchanger 100 to the fluid entering the heat exchanger 100. Such thermal energy transfer may decrease the temperature of the fluid exiting the heat exchanger 100 and may decrease the thermal energy transfer between the outer environment and the fluid flowing through the outer chamber 108. After the fluid flows through the inner chamber 108, the fluid may exit the heat exchanger 100 via the second connector 120.
The outer and inner housings 102, 106 of the heat exchanger 100 exhibits a shape that generally corresponds to each other. However, it is noted that, in some embodiments, the outer and inner housings of the heat exchangers disclosed herein may exhibit different shapes. For example, FIG. 2 is a cross-sectional view of a heat exchanger 200 that includes an outer housing 202 exhibiting a different shape than the inner housing 206, according to an embodiment. Except as otherwise disclosed herein, the heat exchanger 200 is the same as or substantially similar to any of the heat exchangers disclosed herein. For example, the heat exchanger 200 includes the outer housing 202 defining an outer chamber 204 and the inner housing 206 defining an inner chamber 208. The inner housing 206 is disposed in the outer chamber 204.
As previously discussed, the outer housing 202 and the inner housing 206 exhibit different shapes. For example, as illustrated, the outer housing 202 (e.g., the outer surface 203 and/or the inner surface 205 of the outer housing 202) exhibits a generally conical shape and the inner housing 206 (e.g., the outer surface 207 and/or the inner surface 209 of the inner housing 206) exhibits a generally cylindrical shape. However, as will be discussed in more detail herein, the outer housing 202 may exhibit a shape other than a generally conical shape and/or the inner housing 206 may exhibit a shape other than a cylindrical shape.
In an embodiment, the different shapes of the outer housing 202 and the inner housing 206 may be selected to increase the volume of the outer chamber 204 and minimize the volume of the inner chamber 208 than if the outer housing 202 and the inner housing 206 exhibited the same shape. For example, the shapes of the outer housing 202 and the inner housing 206 illustrated in FIG. 2 causes the outer chamber 204 to exhibit a volume that is greater than the volume of the outer chamber 104 illustrated in FIG. 1B, assuming the size of the outer housings 102, 202 are the same. Increasing the volume of the outer chamber 204 increases the residence time of the fluid in the outer chamber 204. The increased residence time in the outer chamber 204 increases the quantity of thermal energy transfer between the outer environment and the fluid in the outer chamber 204. In other words, the increased residence time of the fluid in the outer chamber 204 increases the temperature change between the fluid entering the outer chamber 204 and exiting the outer chamber 204 which, in turn, increases the temperature change between the fluid entering the heat exchanger 200 and the fluid exiting the heat exchanger 200. It is noted that the increased volume of the outer chamber 204 may decrease the percentage of the fluid that is actively participating in thermal energy transfer with the outer environment and may increase the likelihood of dead spots forming in the outer chamber 204.
As previously discussed, the outer housing of the heat exchangers disclosed herein may exhibit a shape other than a generally conical shape. For example, FIG. 3A is an isometric view of a heat exchanger 300 including an outer housing 302 exhibiting a generally cylindrical shape, according to an embodiment. FIG. 3B is a cross-sectional view of the heat exchanger 300 taken along plane 3B-3B, according to an embodiment. Except as otherwise disclosed herein, the heat exchanger 300 may be the same as or substantially similar to any of the heat exchangers disclosed herein. For example, the heat exchanger 300 includes the outer housing 302 defining an outer chamber 304 and an inner housing 306 defining an inner chamber 308. The inner housing 306 is disposed in the outer chamber 304.
As previously discussed, the outer housing 302 exhibits a generally cylindrical shape. For example, at least the outer surface 303 of the outer housing 302 may exhibit the generally cylindrical shape. The generally cylindrical shape of the outer housing 302 increases the volume of the outer chamber 304 than a substantially similarly sized outer housing (i.e., an outer housing having the same length and maximum outer dimension as the outer housing 302) exhibiting a generally conical shape. As previously discussed, increasing the volume of the outer chamber 304 may increase the residence time of the fluid in the outer chamber 304 which, in turn, increases the quantity of thermal energy transfer between the outer environment and the fluid in the outer chamber 304. However, the generally cylindrical shape of the outer housing 302 decreases the surface area to volume ratio of the heat exchanger 300 than if the outer housing 302 exhibited a generally conical shape. As previously discussed, the efficiency of the thermal energy transfer between the outer environment and the fluid in the heat exchanger 300 depends, in part, on the surface area to volume ratio of the outer housing 302. As such, the generally cylindrical shape of the outer housing 302 may be more beneficial in some applications than the generally conical shape of the outer housing 102, 202 of FIGS. 1A-2 and vice versa.
FIG. 4A is an isometric view of a heat exchanger 400 including an outer housing 402 exhibiting a truncated generally conical shape, according to an embodiment. FIG. 4B is a cross-sectional view of the heat exchanger 400 taken along plane 4B-4B, according to an embodiment. Except as otherwise disclosed herein, the heat exchanger 400 may be the same as or substantially similar to any of the heat exchangers disclosed herein. For example, the heat exchanger 400 includes the outer housing 402 defining an outer chamber 404 and an inner housing 406 defining an inner chamber 408. The inner housing 406 is disposed in the outer chamber 404.
As previously discussed, the outer housing 402 exhibits a truncated generally conical shape. For example, at least the outer surface 403 of the outer housing 402 may exhibit the truncated generally conical shape. The truncated generally conical shape of the outer housing 402 allows the outer housing 402 to exhibit a volume that is greater than a substantially similarly sized outer housing exhibiting a generally conical shape, assuming the maximum diameter and length of the two outer housings are the same. The truncated generally conical shape of the outer housing 402 also eliminates or at least minimizes the dead spot typically formed at or near the bottom region 414 of the outer housing 402 compared to the conical outer housings 102, 202 of FIGS. 1A-2 . The truncated generally conical shape of the outer housing 402 allows the outer housing 402 to exhibit a greater surface area to volume ratio than if a similarly sized outer housing exhibiting a generally cylindrical shape, assuming the maximum diameter and length of the two outer housings are the same. As such, the truncated generally conical shape of the outer housing 402 may be an improvement over the generally conical and generally cylindrical outer housings disclosed herein. For example, the truncated generally conical shape of the outer housing 402 may allow the heat exchanger 400 to be used in applications where the conical outer housings may be used, applications where the cylindrical outer housings may be used, and in applications where one or both of the conical outer housings or the cylindrical outer housings may be used. In other words, the generally truncated outer housing 402 allows the heat exchanger 400 to exhibit the benefits while minimizing the down sides of both the generally conical and generally cylindrical outer housings.
FIG. 5A is a cross-sectional view of a heat exchanger 500, according to an embodiment. Except as otherwise disclosed herein, the heat exchanger 500 is the same or substantially similar to any of the heat exchangers disclosed herein. For example, the heat exchanger 500 includes an outer housing 502 defining an outer chamber 504. The heat exchanger 500 also includes an inner housing 504 disposed in the outer chamber 504 that defines an inner chamber 506.
The heat exchanger 500 includes at least one helical structure 522 disposed in the outer chamber 504. The helical structure 522 extends between the inner surface 505 of the outer housing 502 to the outer surface 507 of the inner housing 506. The helical structure 522 may be formed from any of the materials disclosed herein. In an embodiment, as shown, the helical structure 522 is integrally formed with at least one of the outer housing 502 or the inner housing 506. In an embodiment, the helical structure 522 is distinct from at least one of the outer housing 502 or the inner housing 506. In such an embodiment, the helical structure 522 may be attached to (e.g., via welding) to the outer housing 502 and/or the inner housing 504.
The helical structure 522 causes the heat exchanger 500 to exhibit an improvement over at least some conventional heat exchangers. For example, it is currently believed that increasing the speed of the fluid flowing through the heat exchanger improves the efficiency of the thermal energy transfer between the outer environment and the fluid flowing through the heat exchangers. Conventional heat exchangers increase the speed of the fluid flowing through the heat exchanger by increasing the pressures of the fluid flowing through the conventional heat exchanger. However, the increased speed of the fluid flowing through the convention heat exchanger decreases the residence time of the fluid in the heat exchanger which, in turn, decreases the amount of thermal energy transfer between the fluid and the outer environment. The increased pressure of the fluid also requires more powerful pumps and more electrical power to move the fluid through the conventional heat exchanger thereby increasing the energy costs of using the conventional heat exchanger. Further, the increased pressure of the fluid requires the conventional heat exchanger to have a thicker outer housing (which decreases the efficiency of thermal energy transfer between the outer environment and the fluid) to withstand the increased pressure or increase the risk of the conventional heat exchanger failing. However, the helical structure 522 is able to increase the speed of the fluid flowing through the heat exchanger 500 without requiring an increase of pressure of the fluid flowing through the heat exchanger 500. For example, the presence of the heat exchanger 500 has little to no effect on the quantity of fluid that flows into and out of the heat exchanger 500 over a period of time compared to a substantially similar heat exchanger 500 that does not include the heat exchanger 500 at the same pressure of the fluid. In other words, the presence of the heat exchanger 500 does not decrease the residence time of the fluid in the heat exchanger 500. However, the helical structure 522 increases the path along which the fluid must flow. This increased flow path increases the speed at which the fluid flows through the heat exchanger 500 and, in particular, the speed of the fluid flowing through the outer chamber 504. Thus, the helical structure 522 increases the speed of the fluid flowing through the heat exchanger 500 thereby improving thermal energy transfer between the outer environment and the fluid without requiring an increase in the pressure of the fluid, decreasing the residence time of the fluid in the outer chamber 504, or requiring a thicker outer housing 502.
The helical structure 522 also provides several additional benefits to the heat exchanger 500. In an example, the helical structure 522 provides additional structural support to the outer housing 502. In other words, the helical structure 522 decreases the likelihood that the outer housing 502 fails, buckles, or is otherwise damaged when disposed in the outer environment (e.g., buried in the ground). The added structural support provided by the helical structure 522 allows the thickness of the outer housing 502 to be decreased which, in turn, increases the efficiency of the thermal energy transfer between the outer environment and the fluid flowing through the outer chamber 504. In an example, the helical structure 522 reduces the likelihood of undesired fluid flow through the outer chamber 504 (e.g., the formation of dead spots or regions of slow flowing fluid develops in the outer chamber 504) compared to a substantially similar heat exchanger that does not include the helical structure.
The helical structure 522 may exhibit a pitch P measured between vertically (i.e., a direction extending from the top region 512 to the bottom region 514 that may be parallel to a longitudinal axis of the outer housing 502) between adjacent portions of the helical structure 522. The pitch P may be selected to be about 1 cm or greater, about 2 cm or greater, about 3 cm or greater, about 5 cm or greater, about 7.5 cm or greater, about 10 cm or greater, about 12.5 cm or greater, about 15 cm or greater, about 17.5 cm or greater, about 20 cm or greater, about 25 cm or greater, about 30 cm or greater, about 35 cm or greater, about 40 cm or greater, about 50 cm or greater, or in ranges of about 1 cm to about 3 cm, about 2 cm to about 5 cm, about 3 cm to about 7.5 cm, about 5 cm to about 10 cm, about 7.5 cm to about 12.5 cm, about 10 cm to about 15 cm, about 12.5 cm to about 17.5 cm, about 15 cm to about 20 cm, about 17.5 cm to about 25 cm, about 20 cm to about 30 cm, about 25 cm to about 35 cm, about 30 cm to about 40 cm, or about 35 cm to about 50 cm. The pitch P may be selected for a number of reasons. In an example, the pitch P may be selected based on the distance between the outer housing 502 and the inner housing 504, wherein the pitch P may be increased as the distance between the outer housing 502 and the inner housing 504 is increased. In an example, the pitch P may be selected based on the thickness of the outer housing 502 since decreasing the pitch P may cause the helical structure 522 to provide additional structure to the outer housing 502. In an example, the pitch P may be selected based on the desired speed at which the fluid flows through the outer chamber 504 since decreasing the pitch P may increase the fluid flow path which, in turn, increases the speed of the fluid. In an example, the pitch P may be selected based on an acceptable pressure drop between the fluid entering and exiting the outer chamber 504 since, generally, increasing the pitch P may cause a slight pressure drop.
In an embodiment, the pitch P of the helical structure 522 may vary along at least a portion of a length of the outer housing 502. Varying the pitch P along at least a portion of the length of the outer housing 502 allows the speed of the fluid to be varied within the outer chamber 504. It is noted that varying the pitch P of the helical structure 522 does not change the residence time of the fluid in any particular region of the outer chamber 504 than if the pitch P of the helical structure 522 remained constant. For example, referring to the particular embodiment shown in FIG. 5A, the fluid spends the same amount of time in the top half of the outer chamber 504 as the bottom half of the outer chamber 504 even though the pitch P of the helical structure 522 is greater in the top half than the bottom half (i.e., the speed of the fluid flowing in the bottom half is greater than the fluid flowing in the top half). Thus, varying the speed of the fluid by varying the pitch P does not vary the residency time of the fluid in a particular region of the outer chamber 504.
In a particular embodiment, as shown, the pitch P of the helical structure 522 decreases with increasing distance from the top region 512. When the outer environment is ground, the temperature of the outer environment relatively close to the surface (e.g., within a foot of the surface) varies more than the temperature of the outer environment that is relatively far from the surface (e.g., about 1.5 feet or more from the surface). For instance, during the summer, the temperature of the outer environment relatively close to the surface is relatively hot while the temperature of the outer environment relatively far from the surface is relatively cool and, during the winter, the temperature of the outer environment relatively close to the surface is relatively cool while the temperature of the outer environment relatively far from the surface is relatively hot. Varying the pitch P of the helical structure 522 such that the pitch P decreases with increasing distance from the top region 512 is able to leverage this temperature difference. For example, during the summer, the fluid entering the heat exchanger 500 may be relatively hot. The larger pitch P of the helical structure 522 at or near the top region 512 slows down the speed of the fluid thereby decreasing thermal energy transfer between the relatively hot fluid and the relatively hot outer environment. As the fluid flows down the outer chamber 504, the temperature of the outer environment decreases and, due to the decreased pitch P of the helical structure 522, the speed of the fluid increases. The increased speed of the fluid improves thermal energy transfer between the outer environment and the fluid at or near the bottom region 514 thereby allowing for improved cooling of the fluid by the relatively cool outer environment. It is noted that similar benefits occur during the winter since the fluid entering the heat exchanger 500 is relatively cool and the temperature of the outer environment may increase with increasing distance from the top region 512.
It is also noted that varying the pitch P to decrease with increasing distance from the top region 512 also improves the operation of the heat exchanger 500 when the fluid enters the outer chamber 504 from the inner chamber 508 (i.e., the first connector 518 is an outlet and the second connector 520 is an inlet). For example, during the summer, the fluid flowing into the outer chamber 504 from the inner chamber 508 is relatively hot. The temperature of the outer environment at or near the bottom region 514 is relatively cool. Thus, a relatively large temperature difference between the relatively hot fluid and the relatively cool outer environment causes a relatively large thermal energy transfer between the fluid and the outer environment. The relatively large thermal energy transfer between the fluid and the outer environment may be enhanced due to the high speed of the fluid flowing through the helical structure 522 because of the relatively small pitch P of the helical structure 522 at or near the bottom region 514. As the cooled fluid rises in the outer chamber 504, the temperature of the outer environment deceases such that the temperature difference between the cooled fluid and the outer environment decreases. In fact, in some examples, the temperature of the outer environment may exceed the temperature of the cooled fluid at or near the top region 512. The decreased speed of the cooled fluid flowing through the outer chamber 504 at or near the top region 512 minimizes thermal energy transfer between the cooled fluid and the relatively hot outer environment thereby preventing or minimizing the undesirable flow of heat from the relatively hot outer environment to the cooled fluid. Again, it is noted that similar benefits occur during the winter.
The helical structure 522 may exhibit a maximum pitch and a minimum pitch. Generally, the maximum pitch is located at or near the top region 512 and the minimum pitch is located at or near the bottom region 514 to maximize the effect of varying the pitch of the helical structure 522 when the heat exchanger 500 is buried in the ground. The maximum pitch and the minimum pitch is located at or near the top and bottom regions 512, 514, respectively, when immediately adjacent to or within 10% of the length of the outer chamber 504 to their respective region. However, it is noted that the maximum pitch may be spaced from the top region 512 (e.g., at or near the bottom region 514) and/or the minimum pitch may be spaced from the bottom region 514 (e.g., at or near the top region 512). The maximum pitch may be greater than the minimum pitch by about 10% or more, about 20% or more, about 30% or more, about 50% or more, about 75% or more, about 100% or more, about 125% or more, about 150% or more, about 200% or more, about 250% or more, about 300% or more, about 350% or more, about 400% or more, about 500% or more, about 600% or more, about 750% or more, about 1000% or more, or in ranges of about 10% to about 30%, about 20% to about 50%, about 30% to about 75%, about 50% to about 100%, about 75% to about 125%, about 100% to about 150%, about 125% to about 200%, about 150% to about 250%, about 200% to about 300%, about 250% to about 500%, about 300% to about 600%, about 500% to about 750%, or about 600% to about 1000%. The difference between the maximum pitch and the minimum pitch may be selected based on a number of factors. In an example, the difference of the maximum pitch and the minimum pitch may be selected for any of the same reasons that the pitch P is selected, as discussed above. In an example, the maximum pitch and the minimum pitch may be selected based on the historical ground temperature where the heat exchanger 500 is buried to maximize the thermal energy transfer between the fluid and the outer environment.
FIG. 5B is an enlarged cross-sectional view of a portion of the heat exchanger 500 taken from the circle 5B shown in FIG. 5A. In an embodiment, as shown in FIG. 5B, the intersection between the helical structure 522 and the outer housing 504 (hereinafter referred to as “outer corner 524”) may be rounded. The rounded outer corner 524 prevents the formation of stress concentrators between the helical structure 522 that may otherwise cause the helical structure 522 to become detached from the outer housing 502 and/or cause failure (e.g., cracking or rupturing) of the outer housing 502 or the helical structure 522. The rounded outer corner 524 also decreases the formation of dead spots or locations of slow flowing fluid that may otherwise form at the outer corner 524. In an example, the rounded outer corner 524 may be integrally formed with at least one of the outer housing 502 or the helical structure 522. In an example, the rounded outer corner 524 may be formed by positioning a distinct element on the outer corner 524. In an embodiment, not shown, the outer corner 524 is not rounded. It is noted that the intersection between the helical structure 522 and the inner housing 506 may also be rounded for the same reasons as the outer corner 524.
The helical structures disclosed herein exhibit a shape that generally corresponds to the shape of the outer chamber 504. For example, the helical structure 522 shown in FIG. 5A exhibits a generally hollow cylindrical shape since the outer chamber 504 exhibits a generally hollow cylindrical shape. However, it is noted that the helical structures may exhibit different shapes depending on the different shapes of the outer chambers disclosed herein. For example, FIG. 6 is a cross-sectional view of a heat exchanger 600 including a helical structure 622, according to an embodiment. The heat exchanger 600 is the same as the heat exchanger 400 shown in FIGS. 4A and 4B except that the heat exchanger 600 includes a helical structure 622. The helical structure 622 exhibits a hollow generally truncated conical shape since the outer chamber 604 exhibits a generally hollow truncated conical shape.
It is noted that the heat exchangers illustrated in FIGS. 1A-2 may also include a helical structure. For example, the heat exchanger 100 and the heat exchanger 200 may include a helical structure exhibiting hollow generally conical shape or a truncated generally conical shape. The helical structure of the heat exchangers 100, 200 may extend to or near the openings 110, 210 or past the openings 110, 210. The helical structure of the heat exchangers 100, 200 may also minimize the dead spot formed at or near the apexes thereof. It is noted that the hollow portion of the helical structure of the heat exchanger 100 exhibits a generally conical shape while the hollow portion of the helical structures of the heat exchangers 200, 500, and 600 exhibit a generally cylindrical shape. In other words, the hollow portion of the helical structure exhibits a shape that generally corresponds to the shape of the inner housing.
The outer housings of the heat exchangers disclosed herein may include one or more surface features formed on the outer surface of the outer chamber. For example, FIG. 7 is an isometric view of a heat exchanger 700 including one or more surface features, according to an embodiment. Except as otherwise disclosed herein, the heat exchanger 700 is the same as or substantially similar to any of the heat exchangers disclosed herein. For example, the heat exchanger 700 includes an outer housing 702 and an inner housing (not shown).
The outer housing 702 includes an outer surface 703 and the outer surface 703 includes one or more surface features. In the illustrated embodiment, the surface features includes one or more fins 726. The fins 726 increase the surface area of the outer housing 702 which, in turn, increases thermal energy transfer between the fluid flowing through the outer chamber and the outer environment. The fins 726 also increase the volume of the outer environment that is involved in the thermal energy transfer. The fins 726 further provide structural support to the outer housing 702 thereby allowing the thickness of the walls of the outer housing 702 to be decreased. The fins 726 may be integrally formed with the rest of the outer housing 702 or may be distinct from and attached to the rest of the outer housing 702.
The fins 726 may exhibit any suitable shape. In an embodiment, as shown, the fins 726 may exhibit a generally helical shape. The generally helical shape of the fins 726 may facilitate insertion of the heat exchanger 700 into and/or extraction of the heat exchanger 700 out of the outer environment by rotating the outer housing 702. In an embodiment, instead of or in addition to the helical fins 726, the fins 726 may exhibit a non-helical shape. In an example, the non-helical shape of the fins 726 may include a hollow shape (e.g., annular shape) extending along an outer periphery (e.g., circumference) of the outer surface 703. The hollow shape of the fins 726 may prevent or at least inhibit the heat exchanger 700 from moving up or down in the outer environment. In an example, the non-helical shape of the fins 726 may include fins extending between the top region 712 and the bottom region 714.
The outer housing 702 may include any number of fins 726. In an example, as illustrated, the outer housing 702 may include a single fin 726. In an example, the outer housing 702 may include a plurality of fins 726, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, or greater than 10 fins 726.
The heat exchangers disclosed herein may include surface features other than or in addition to the fins 726. For example, FIG. 8 is a cross-sectional view of a portion of a wall of an outer housing 802, according to an embodiment. Except as otherwise disclosed herein, the outer housing 802 may be the same as or substantially similar to any of the outer housings disclosed herein and may be used in any of the heat exchangers disclosed herein. The outer surface 803 of the outer housing 802 includes one or more surface features. The surface features include a textured surface. The textured surface of the outer housing 802 increases the surface area of the outer housing 802 which, in turn, increases thermal energy transfer between the fluid in the outer chamber and the outer environment.
In an embodiment, the textured surface of the outer surface 803 may include a plurality of barbs 826. The barbs 826 may include at least two tapered surfaces that meet at an apex 828. The apex 828 may be oriented to generally point towards the surface of the ground. As such, the apex 828 may prevent or at least inhibit movement of the outer housing 802 towards the surface of the ground. However, the barbs 826 may not prevent or inhibit movement of the outer housing 802 into the ground. In other words, the barbs 826 may not inhibit installing the outer housing 802 in the ground.
It is noted that the heat exchangers disclosed herein may include surface features other than the fins 726 and/or the barbs 826. For example, the surface features may include a roughened surface or small protruding features. Also, it is noted that, in some embodiments, at least one of the inner surfaces of the outer housings disclosed herein, the outer surfaces of the inner housings disclosed herein, or the inner surfaces of the inner housings disclosed herein may include the surface features disclosed herein since such surface features may also enable better heat transfer.
In an embodiment, the heat exchangers disclosed herein may include an insulating material or coating. For example, FIG. 9 is a cross-sectional view of a heat exchanger 900, according to an embodiment. Except as otherwise disclosed herein, the heat exchanger 900 may be the same or substantially similar to any of the heat exchangers disclosed herein. For example, the heat exchanger 900 may include an outer housing 902 defining an outer chamber 904.
The heat exchanger 900 includes an insulating coating 930 disposed on a portion of the outer chamber 904. For example, as illustrated, the coating 930 may be disposed on a portion of the outer surface 903 of the outer housing 902 since it may be easier to coat the outer surface 903 of the outer housing 902 than the inner surface 905. However, it is noted that the coating 930 may be disposed on a portion of the inner surface 905 instead of or in addition to a portion of the outer surface 903.
The coating 930 may be formed from any material exhibiting a thermal conductivity that is less than the material forming the outer housing 902. For example, the coating 930 may be formed from silicone, a polymer foam, or any other suitable insulating coating. The coating 930 may be disposed on a portion of the outer housing 902 using a spray-on technique, painting the coating 930 onto the outer housing 902, applying a sticker or sleeve to the outer housing 902, or any other suitable technique.
The coating 930 may be disposed on portions of the outer housing 902 at or near the top region 912. The coating 930 may also extend from the top region 912 along a portion of a length of the outer housing 902 towards the bottom region 914. As previously discussed, the temperature of the outer environment at or near the top region 912 may cause undesired thermal energy transfer between the fluid flowing through the outer chamber 904 and the outer environment. The coating 930 minimizes or prevents such undesirable thermal energy transfer.
It is noted that, instead of coating the outer housing 902, the portions of outer housing 902 defining the top region 912 and extending along a portion of the length of the outer housing 902 may be formed from an insulating material exhibiting a thermal conductivity that is less than the rest of the outer housing 902.
FIG. 10 is a cross-sectional view of a heat exchanger 1000 including an insulating material, according to an embodiment. Except as otherwise disclosed herein, the heat exchanger 1000 may be the same as or substantially similar to any of the heat exchangers disclosed herein. For example, the heat exchanger 1000 may include an outer housing 1002 and an inner housing 1006.
The inner housing 1006 may include an insulating coating 1030 disposed on at least a portion of at least one surface thereof. For example, as shown, the coating 1030 may be disposed on at least a portion of the outer surface 1007 of the inner housing 1006 since the outer surface 1007 may be easier to coat than the inner surface 1009. However, it is noted that at least a portion of the inner surface 1009 may be coated instead of or in addition to the outer surface 1007. The coating 1030 may be the same as any of the coatings disclosed herein and may be applied to the inner housing 1006 using any of the techniques disclosed herein.
As previously discussed, thermal energy transfer between the fluid flowing in the outer chamber 1004 and the inner chamber 1008 may be undesired. The coating 1030 prevents or at least minimizes the thermal energy transfer between the fluids flowing in the outer chamber 1004 and the inner chamber 1008.
The heat exchangers illustrated in FIGS. 1A-10 exhibit a non-modular design. However, it is noted that any of the heat exchangers disclosed herein may exhibit a modular design. FIG. 11A is an isometric view of a heat exchanger 1100 exhibiting a modular design, according to an embodiment. FIG. 11B is a cross-sectional view of the heat exchanger 1100 taken along plane 11B-11B. FIG. 11C is an exploded cross-sectional view of the heat exchanger 1100. Except as otherwise disclosed herein, when assembled, the heat exchanger 1100 is the same as or substantially similar to any of the heat exchangers disclosed herein. For example, when assembled, the heat exchanger 1100 includes an outer housing defining an outer chamber and an inner housing defining an inner chamber. The inner housing is disposed in the outer chamber. The heat exchanger 1100 may also include a helical structure 1122 disposed in the outer chamber.
The heat exchanger 1100 is formed from a plurality of modular structures that are configured to be attached together. For example, the heat exchanger 1100 includes a top modular structure 1140, a bottom modular structure 1142, and, optionally, one or more intermediate modular structures 1144 (collectively referred to as “the modular structures”). The top modular structure 1140 defines the top region 1112 of the outer housing and the bottom modular structure 1142 defines the bottom region 1114 of the outer housing. Each of the modular structures form a portion of the outer housing. For example, the top modular structure 1140 may form a first, top portion 1102 a of the outer housing, the bottom modular structure 1142 may form a second, bottom portion 1102 b of the outer housing, and, optionally, each of the intermediate modular structures 1144 may form an intermediate portion 1102 c of the outer housing. Similarly, each of the portions of the outer housing may define a portion of the outer chamber. For example, the first, top portion 1102 a of the outer housing formed by the top modular structure 1140 may define a first, top portion 1104 a of the outer chamber, the second, bottom portion 1102 b of the outer housing formed by the bottom modular structure 1142 may define a first, bottom portion 1104 b of the outer chamber, and, optionally, each of the intermediate portions 1102 c of the outer housing formed by the intermediate modular structures 1144 may define an intermediate portion 1104 c of the outer chamber.
At least the top modular structure 1140 defines at least a portion of the inner housing. Optionally, as shown, the bottom modular structure 1142 and/or one or more of the intermediate portions 1144 also define a portion of the inner housing. For example, the top modular structure 1140 may form a first, top portion 1106 a of the inner housing. If the bottom modular structure 1142 and/or the intermediate modular structure 1144 form part of the inner housing, the bottom modular structure 1142 may form a second, bottom portion 1106 b of the inner housing, and each of the intermediate modular structures 1144 may form an intermediate portion 1106 c of the inner housing. Similarly, each of the portions of the inner housing may define a portion of the inner chamber. For example, the first, top portion 1106 a of the inner housing formed by the top modular structure 1140 may define a first, top portion 1108 a of the inner chamber, the second, bottom portion 1106 b of the inner housing formed by the bottom modular structure 1142 may define a first, bottom portion 1108 b of the inner chamber, and, optionally, each of the intermediate portions 1106 c of the inner housing formed by the intermediate modular structures 1144 may define an intermediate portion 1108 c of the inner chamber.
In an embodiment, one or more of the modular structures of the heat exchanger 1100 may include a helical structure 1122. In an example, as shown, only the intermediate modular structure 1144 includes the helical structure 1122. In such an example, the top modular structure 1140 and the bottom modular structure 1142 may be used to assemble heat exchangers that include and do not include the helical structure 1122. In other words, the top modular structure 1140 and the bottom modular structure 1142 may be used with different heat exchangers thereby decreasing the number of modular structures that need to be manufactured, procured, etc. In an example, at least one of the top modular structure 1140 or the bottom modular structure 1142 may include a helical structure 1122. The helical structure 1122 may be the same as any of the helical structures disclosed herein when the heat exchanger 1100 is assembled. For example, the pitch of the helical structure 1122 may change. In such an example, one of the intermediate modular structures 1144 may include a first helical structure exhibiting a first pitch and another one of the intermediate modular structures 1144 may include a second helical structure exhibiting a second pitch that is different than the first helical structure. Thus, the modular design of the heat exchanger 1100 allows the same heat exchanger 1100 to be configured to include different helical structures, depending on the particular application of the heat exchanger 1100.
Each of the modular structures may be attached together to form the heat exchanger 1100. In an embodiment, the top modular structure 1140 is directly attached to the bottom modular structure 1142 when the heat exchanger 1100 does not include the intermediate modular structure 1144. In such an embodiment, the heat exchanger 1100 exhibits a minimum length measured from the top region 1112 to the bottom region 1114. In an embodiment, as shown, the heat exchanger 1100 includes a single intermediate modular structure 1144. In such an embodiment, the top modular structure 1140 may be attached to a first, top side 1146 of the intermediate modular structure 1144 and the bottom modular structure 1142 may be attached to a second, bottom side 1148 of the intermediate modular structure 1144 that is opposite the first, top side 1146. When the heat exchanger 1100 includes a single intermediate modular structure 1144, the heat exchanger 1100 exhibits a first intermediate length that is greater than the minimum length. In an embodiment, the heat exchanger 1100 includes two intermediate modular structures 1144 (i.e., a first intermediate modular structure and a second intermediate modular structure). In such an embodiment, the top modular structure 1140 is attached to a first, top side of a first intermediate modular structure, the bottom modular structure 1142 is attached to the second, bottom side of the second intermediate modular structure, and the second, bottom side of the first intermediate modular structure is attached to the first, top side of the second intermediate modular structure. When the heat exchanger 1100 includes two intermediate modular structures 1144, the heat exchanger 1100 exhibits a second intermediate length that is greater than the first intermediate length. In an embodiment, the heat exchanger 1100 may include three or more intermediate modular structures (e.g., a first intermediate modular structure, a second intermediate modular structure, and one or more addition intermediate modular structures). In such an embodiment, the top modular structure 1140 is attached to a first, top side 1146 of a first intermediate modular structure, the bottom modular structure 1142 is attached to the second, bottom side 1148 of the second intermediate modular structure, and the second, bottom side of the first intermediate modular structure and the first, top side of the second intermediate modular structure are attached to the one or more additional intermediate structures. When the heat exchanger 1100 includes the one or more additional intermediate modular structures, the heat exchanger 1100 exhibits a third length that is greater than the second length.
As shown above, the heat exchanger 1100 may be configured to exhibit a plurality of different lengths depending on the number of intermediate modular structures 1144 included in the heat exchanger 1100. As such, the length of the heat exchanger 1100 may be configured for a variety of different embodiments. For example, the heat exchanger 1100 may be configured to exhibit a length that is greater than 30 m when the heat exchanger 1100 is used in a system that includes a single, deep hole. Such a system may be used when space is limited, such as when the system is used to heat and cool a house or building that has limited space (e.g., a house or building located in a densely populated area). Meanwhile, the same heat exchanger 1100 may be configured to exhibit a length that is about 1 m to about 2 m when the heat exchanger 1100 is used in a system that includes a plurality of shallow holes. Such a system may be used to heat or cool a home or building that has ample space to dig holes, such as a home in the suburbs. The same heat exchanger 1100 may also be used to retrieve thermal energy from waste material. The same heat exchanger 1100 may be used for each of these embodiments because the heat exchanger 1100 exhibits a modular design that allows the length of the heat exchanger 1100 to be configured for each application.
The modular structures may be attached together using any suitable technique. In an embodiment, one or more of the modular structures may be configured to be reversibly attached together. The modular structures may be reversibly attached together when the modular structures may be attached and detached from each other without damaging any of the modular structures. An example of a technique that reversibly attaches the modular structures together includes threadedly attaching the modular structures together, as shown. Other examples of reversibly attaching the modular structures together includes using screws, bolts, pins, or other mechanical devices to reversibly attach the modular structures together. Reversibly attaching the modular structures together allows for in-field assembly and/or in-field adjustment of the heat exchanger 1100. For example, the heat exchanger 1100 may be assembled but, after assembling the heat exchanger 1100, it may be determined that the length of the heat exchanger 1100 needed to be adjusted. Reversibly attaching the modular structures together allows the length of the heat exchanger 1100 to be adjusted in-field without sending the heat exchanger 1100 to a specialized facility for disassembly or without requiring a new heat exchanger to be constructed and delivered. In an embodiment, the modular structures may be permanently attached together. Examples of permanently attaching the modular structures together includes welding the modular structures together. Permanently attaching the modular structures together may eliminate the need to form complicated features in the modular structures (e.g., threaded portions) which make manufacturing the modular structures more difficult.
The modular design of the heat exchanger 1100 shown in FIGS. 11A-11C causes the heat exchanger 1100 to exhibit a generally cylindrical shape. However, it is noted that the modular design discussed above may be used with differently shaped heat exchangers. For example, the top modular structure 1140 may exhibit a truncated conical shape. In such an example, the heat exchanger 1100 as a whole may exhibit a generally conical shape (e.g., as shown in FIGS. 1A-2 ) or a truncated generally conical shape (e.g., as shown in FIGS. 4A and 4B) depending on whether the bottom modular structure 1142 exhibits a conical or truncated conical shape. As such, the modular design allows the heat exchanger 1100 to exhibit a variety of shapes depending on the shapes of the modular structures thereof. In an example, the heat exchanger 1100 may be assembled from a plurality of modular structures, wherein at least one of the modular structures exhibits a generally conical shape and/or truncated generally conical shape and at least one other modular structure exhibits a cylindrical shape.
FIG. 12 is a diagram of a geothermal system 1250 that may include any of the heat exchangers disclosed herein, according to an embodiment. The system 1250 may be used in conjunction with a building 1252. For example, the system 1250 may be used to heat or cool the building 1252. The building 1252 may include, for example, a home, a commercial building, an industrial building, or any other suitable building. The system 1250 includes one or more heat exchangers 1200. The heat exchangers 1200 may be buried in the ground 1254. The heat exchangers 1200 may include any of the heat exchangers disclosed herein. When the system 1250 includes a plurality of heat exchangers 1200, the heat exchangers 1200 may be connected in series (as shown) or in parallel. The system 1250 may also include pipes 1256. At least a portion of the pipes 1256 may be buried in the ground 1254, at least partially positioned above the ground 1254, and/or insulated to prevent thermal energy transfer between a fluid flowing through the pipes 1256 and the ground 1254. The system 1250 also includes at least one pump 1258 in fluid communication with the pipes 1256 that is configured to move the fluid through the heat exchangers 1200 and the pipes 1256.
The system 1250 may also include a heat pump 1260. In an embodiment, the heat pump 1260 may be used to facilitate the heating and cooling of the building 1250 using the fluid. For example, the fluid may exhibit a temperature of about 14° C. which may correspond to the average temperature of the ground. During the winter, a heat pump fluid of the heat pump 1260 may receive thermal energy from the fluid which causes the fluid to heat the heat pump fluid and evaporate it. The heat pump 1260 may then compress the heat pump fluid to higher pressure thus further increase the temperature of the heat pump fluid (e.g., to a temperature greater than room temperature). The heat pump 1260 may then use the increased temperature of the heat pump fluid to heat the building 1250. The heat pump 1260 may then cool the heat pump fluid by decompressing the heat pump fluid. The cooled heat pump fluid may then cool the fluid before the fluid returns to the heat exchangers 1200. The opposite process may occur during the summer thereby allowing the heat pump 1260 to cool the building.
The system 1250 may include any suitable number of heat exchangers 1200. For example, the system 1250 may include a single heat exchanger 1200, 2 to 4 heat exchangers 1200, 3 to 5 heat exchangers 1200, 4 to 6 heat exchangers 1200, 5 to 7 heat exchangers 1200, 6 to 8 heat exchangers 1200, 7 to 9 heat exchangers 1200, 8 to 10 heat exchangers 1200, 9 to 12 heat exchangers 1200, 10 to 15 heat exchangers 1200, 12 to 17 heat exchangers 1200, 15 to 20 heat exchangers 1200, 17 to 25 heat exchangers 1200, 20 to 30 heat exchangers 1200, 25 to 35 heat exchangers 1200, 30 to 40 heat exchangers 1200, 35 to 45 heat exchangers 1200, 40 to 50 heat exchangers 1200, 45 to 60 heat exchangers 1200, 50 to 70 heat exchangers 1200, 60 to 80 heat exchangers 1200, 70 to 90 heat exchangers 1200, 80 to 100 heat exchangers 1200, or greater than 100 heat exchangers 1200. The number of heat exchangers 1200 may be selected for a variety of reasons. In an example, the number of heat exchangers 1200 may be selected based on the side of the building 1252 since more heat exchangers 1200 may be needed to heat and cool a larger building 1252 than a small building 1252. In an example, the number of heat exchangers 1200 may be selected based on the shape of the heat exchangers 1200. For instance, more heat exchangers 1200 may be needed if the heat exchanger 1200 exhibits a conical shape due to the low residence time therein or a cylindrical shape due to the low surface area to volume ratio that if the heat exchanger 1200 exhibits a truncated conical shape. In an example, the number of heat exchangers 1200 may be selected based on the material that forms the heat exchangers 1200. For instance, a system designed to heat the building 1252 may require 30 heat exchangers 1200 formed from polylactic acid and only 10 to 15 heat exchangers 1200 formed from steel. In an example, the number of heat exchangers 1200 may be selected based on the slight seasonal variations in temperature of the ground 1254 and/or how deeply the heat exchangers 1200 are buried in the ground since larger temperature variations in the ground temperature or burying the heat exchangers 1200 shallowly may require more heat exchangers 1200 to heat and cool the building 1252.
During operation, thermal energy flows between the building 1252 and the fluid. For example, during the summer, thermal energy may flow from the building 1252 to the fluid thereby heating the fluid and cooling the building 1252 and, during the winter, thermal energy may flow from the fluid to the building 1252 thereby cooling the fluid and heating the building 1252. The pump 1258 may force the fluid from the building 1252, through the pipes 1256, and into the heat exchangers 1200. The fluid may flow through the heat exchangers 1200 as previously discussed. As the fluid flows through the heat exchangers 1200, the fluid may be cooled (e.g., during the summer) or heated (e.g., during the winter) by the ground 1254. The fluid may then flow back into the building 1252 and, optionally, into the heat pump 1260. The heat pump 1260 may cause the fluid to exhibit a temperature that is less than the ground 1254 during the summer and/or exhibit a temperature that is greater than the ground 1254 during the winter. During the summer, the fluid flowing back into the building 1252 may be cooled by the heat exchangers 1200 thereby allowing thermal energy to flow from the building 1252 into the fluid thereby heating the fluid and cooling the building 1252. During the winter, the fluid flowing back into the building 1252 may be heated by the heat exchangers 1200 thereby allowing thermal energy to flow from the fluid into the building 1252 thereby heating the building 1252 and cooling the fluid.
The system 1250 may include one or more additional elements. In an example, the system 1250 may include a controller 1262. The controller 1262 may be configured to control one or more aspects of the system 1250. For instance, the controller 1262 may direct the pump 1258 to flow the fluid through the pipes 1256, stop the fluid flowing through the pipes 1256, or select the pressure of the fluid flowing through the pipes 1256. In an example, the system 1250 may include one or more sensors 1264. The sensors 1264 are configured to detect one or more characteristics of the system 1250. For instance, the sensors 1264 may include temperature sensors configured to detect the temperature of the building 1252, the ground 1254, and/or the fluid; a pressure sensor configured to detect the pressure of the fluids in the heat exchangers 1200 and/or the pipes 1256; a moisture sensor configured to detect the presence of the fluid in the heat exchanger 1200 and/or the pipes 1256 (e.g., not detecting the fluid in the pipes 1256 may indicate a leak in the system 1250); or any other suitable sensor. The sensors 1264 may transmit the detected characteristics to the controller 1262 and the controller 1262 may control one or more aspects of the system 1250 responsive to receiving the detected characteristics. For instance, the sensor 1264 may detect the temperature within the building 1252. Responsive to receiving the detected temperature of the building 1252, the controller 1262 may direct the pump 1258 to flow fluid through the heat exchangers 1200 and the pipes 1256 or direct the pump 1258 to stop flowing fluid through the heat exchangers 1200 and the pipes 1256. In an example, the system 1250 may include a blower 1266 configured to move thermal energy throughout the building 1252. For instance, the blower 1266 may cause the building to exhibit a substantially constant temperature.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments are contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting.
Terms of degree (e.g., “about,” “substantially,” “generally,” etc.) indicate structurally or functionally insignificant variations. In an example, when the term of degree is included with a term indicating quantity, the term of degree is interpreted to mean±10%, ±5%, or ±2% of the term indicating quantity. In an example, when the term of degree is used to modify a shape, the term of degree indicates that the shape being modified by the term of degree has the appearance of the disclosed shape. For instance, the term of degree may be used to indicate that the shape may have rounded corners instead of sharp corners, curved edges instead of straight edges, one or more protrusions extending therefrom, is oblong, is the same as the disclosed shape, etc.

Claims

What is claimed is:

1. A heat exchanger, comprising:

an outer housing defining an outer chamber;

an inner housing disposed in the outer chamber, the inner housing defining an inner chamber, the inner chamber in fluid communication with the outer chamber via at least one opening at least partially defined by the inner housing;

a first connector in fluid communication with the outer chamber; and

a second connector in fluid communication with the inner chamber;

wherein at least one of:

the outer housing exhibits a generally conical shape or a truncated generally conical shape; or

the heat exchanger further comprises at least one helical structure disposed in the outer chamber, the at least one helical structure extending at least substantially between the outer housing and the inner housing, a pitch of at least a portion of the at least one helical structure varies along at least a portion of a length of the outer housing.

2. The heat exchanger of claim 1, wherein a length of the outer housing measured from a top region of the outer housing to a bottom region of the outer housing is about 1 m to about 2 m.

3. The heat exchanger of claim 1, wherein the inner housing exhibits a shape that generally corresponds to a shape of the outer housing.

4. The heat exchanger of claim 1, wherein the inner housing exhibits a shape that is different than a shape of the outer housing.

5. The heat exchanger of claim 1, wherein the outer housing exhibits a generally conical shape.

6. The heat exchanger of claim 1, wherein the outer housing exhibits a truncated generally conical shape.

7. The heat exchanger of claim 1, wherein the heat exchanger includes the at least one helical structure disposed in the outer chamber.

8. The heat exchanger of claim 7, wherein the outer housing exhibits a generally cylindrical shape.

9. The heat exchanger of claim 7, wherein at least a portion of the at least one helical structure is integrally formed with at least one of at least a portion of the outer housing or at least a portion of the inner housing.

10. The heat exchanger of claim 7, further comprising a rounded corner at an intersection between the at least one helical structure and at least one of the outer housing or the inner housing.

11. The heat exchanger of claim 1, wherein the outer housing includes one or more fins extending from at least one outer surface of the outer housing.

12. The heat exchanger of claim 1, wherein the outer housing includes one or more barbs formed in at least one outer surface of the outer housing.

13. The heat exchanger of claim 1, further comprising an insulating coating disposed on at least a portion of the outer housing.

14. The heat exchanger of claim 1, further comprising an insulating material disposed on at least a portion of the inner housing.

15. The heat exchanger of claim 1, further comprising:

a top modular structure forming a portion of the outer housing and at least a portion of the inner housing; and

a bottom modular structure forming a portion of the outer housing;

wherein the top modular structure and the bottom modular structure are configured to be, either directly or indirectly, attached together.

16. The heat exchanger of claim 15, further comprising one or more intermediate modular structures, the one or more intermediate modular structures configured to be attached to and positioned between the top modular structure and the bottom modular structure.

17. A system, comprising:

at least one heat exchanger, wherein the at least one heat exchanger includes:

an outer housing defining an outer chamber;

a first connector in fluid communication with the outer chamber; and

a second connector in fluid communication with the inner chamber;

wherein at least one of:

the heat exchanger further comprises at least one helical structure disposed in the outer chamber, the at least one helical structure extending at least substantially between the outer housing and the inner housing, a pitch of at least a portion of the at least one helical structure varies along at least a portion of a length of the outer housing;

a pump; and

at least one pipe fluidly connecting the at least one heat exchanger and the pump together;

wherein the pump is configured to flow a fluid through the at least one pipe and the at least one heat exchanger.

18. A method of using a heat exchanger, the method comprising:

providing the at least one heat exchanger that is disposed in an outer environment, the at least one heat exchanger including:

an outer housing defining an outer chamber;

a first connector in fluid communication with the outer chamber; and

a second connector in fluid communication with the inner chamber;

wherein at least one of:

the at least one heat exchanger further comprises at least one helical structure disposed in the outer chamber, the at least one helical structure extending at least substantially between the outer housing and the inner housing, a pitch of at least a portion of the at least one helical structure varies along at least a portion of a length of the outer housing;

flowing a fluid through the outer chamber to transfer thermal energy between the outer environment and the fluid; and

flowing the fluid through the inner chamber.

19. The method of claim 18, wherein flowing a fluid through the inner chamber is performed after flowing a fluid through the outer chamber.

20. The method of claim 18, wherein providing the at least one heat exchanger includes:

digging a hole into the outer environment, wherein the outer environment is ground; and

disposing the at least one heat exchanger into the hole.