Polymer tube-in-shell heat exchanger with twisted tubes

Abstract

A polymeric tube-in-shell heat exchanger having twisted tubes is provided. The heat exchanger may include one or more polymeric tube bundles, each of which includes at least one tube twisted about its length or at least one pair of tubes twisted or wrapped around each other. The polymeric tube-in-shell heat exchanger of the present disclosure having twisted tubes may be particularly suited for applications where the use of polymeric tubes provides advantages, such as with acid solutions, food and beverage fluids, and carbon recovery applications where metal heat exchanger applications destroy amines used for recovery.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This patent application claims the benefit of U.S. Patent Application No. 63 / 262,403, entitled "POLYMERIC TUBE - IN - SHELL HEAT EXCHANGER WITH TWISTED TUBES", filed on October 12, 2021, and is hereby incorporated by reference in its entirety.

[0002] [Technical Field] The present disclosure relates broadly to tube - bundle heat exchangers, particularly to twisted - tube heat exchangers.

Background Art

[0003] Tube - bundle heat exchangers are used in many applications and are widely used in automotive applications. Such heat exchangers typically include a bundle of spaced - apart parallel tubes enclosed within a housing or shell. A first heat - exchange fluid flows through the tubes, while a second heat - exchange fluid flows through the housing, passing through the space in the middle between the outer surfaces of the tubes.

[0004] In a typical structure of a tube - bundle heat exchanger, parallel tubes with a circular cross - section are held in a fixed position at their ends by a perforated header plate, also known as a tube sheet. In addition to holding the tubes, the header plate also provides a seal to prevent fluid communication between the interior of the tubes and the interior of the housing.

Summary of the Invention

[0005] In one embodiment, a polymer tube-in-shell heat exchanger having twisted tubes is provided. The heat exchanger may include one or more polymer tube bundles. At least one of the one or more polymer tube bundles includes one or more sets of two or more tubes that are twisted or wound around one or more tubes, each tube having a tubular wall and a passage configured for a first fluid to flow through, and the heat exchanger is configured for a second fluid to pass through the space between the twisted tubes.

[0006] In some embodiments that can be combined with each of the disclosed embodiments, one or more sets of two or more tubes have a fixed length.

[0007] In some embodiments that may be combined with each of the disclosed embodiments, one or more polymer tube bundles include multiple pairs of tubes that are twisted or wrapped around each other.

[0008] In some embodiments that may be combined with each of the disclosed embodiments, one or more polymer tube bundles include a plurality of three or more tubes that are twisted or wrapped around each other.

[0009] In some embodiments that may be combined with each of the disclosed embodiments, one or more polymer tube bundles include a plurality of non-circular tubes, each tube being twisted around its respective longitudinal direction.

[0010] Some embodiments that may be combined with each of the disclosed embodiments include elliptical / elliptical tubes in which one or more polymer tube bundles are twisted around their respective longitudinal directions.

[0011] Some embodiments that may be combined with each of the disclosed embodiments include a peanut-shaped twisted tube in which one or more polymer tube bundles are twisted around their respective longitudinal directions.

[0012] Some embodiments that may be combined with each of the disclosed embodiments include polygonal twisted tubes in which one or more polymer tube bundles are twisted around their respective longitudinal directions.

[0013] Some embodiments that may be combined with each of the disclosed embodiments include a petal twist tube in which one or more polymer tube bundles are twisted around their respective longitudinal directions.

[0014] Some embodiments that may be combined with each of the disclosed embodiments include a lobulated twisted tube in which one or more polymer tube bundles are twisted around their respective longitudinal directions.

[0015] In some embodiments that may be combined with each of the disclosed embodiments, two or more polymer tubes include one or more external ribs extending outward from the outer surfaces of the two or more tubes, and each tube is twisted around its respective longitudinal direction.

[0016] In some embodiments that may be combined with each of the disclosed embodiments, two or more tubes include one or more internal channels or internal ribs extending outward or inward from the inner surface of one or more tubes, and each tube is twisted around its respective longitudinal direction.

[0017] In some embodiments that may be combined with each of the disclosed embodiments, the heat exchanger also includes a housing positioned outside one or more polymer tube bundles.

[0018] In some embodiments that may be combined with each of the disclosed embodiments, the heat exchanger also includes an outer wrap positioned around one or more polymer tube bundles, the outer wrap being configured to constrict one or more polymer tube bundles so as to allow the tube configuration to provide uniform spacing between tubes and / or reduce the space between the housing and one or more polymer tube bundles.

[0019] In another embodiment, a polymer tube-in-shell heat exchanger having twisted tubes is provided. This heat exchanger may include one or more polymer tube bundles. At least one of the one or more polymer tube bundles includes a plurality of polymer tubes. Each tube includes a tubular wall and a passage configured for a first fluid to flow through. The heat exchanger is configured so that a second fluid passes through the space between the twisted tubes. At least one of the plurality of polymer tubes includes one or more ribs extending from the tubular wall that is twisted around its longitudinal direction.

[0020] In some embodiments that can be combined with each of the disclosed embodiments, the multiple polymer tubes have a fixed length.

[0021] In some embodiments that may be combined with each of the disclosed embodiments, one or more polymer tube bundles include a plurality of non-circular tubes, each tube being twisted around its respective longitudinal direction.

[0022] Some embodiments that may be combined with each of the disclosed embodiments include elliptical or oval-shaped tubes in which one or more polymer tube bundles are twisted around their respective longitudinal directions.

[0023] Some embodiments that may be combined with each of the disclosed embodiments include a peanut-shaped twisted tube in which one or more polymer tube bundles are twisted around their respective longitudinal directions.

[0024] Some embodiments that may be combined with each of the disclosed embodiments include polygonal twisted tubes in which one or more polymer tube bundles are twisted around their respective longitudinal directions.

[0025] Some embodiments that may be combined with each of the disclosed embodiments include a petal twist tube in which one or more polymer tube bundles are twisted around their respective longitudinal directions.

[0026] In some embodiments that can be combined with each of the disclosed embodiments, one or more polymer tube bundles include lobed twist tubes that are twisted around their respective longitudinal directions.

[0027] In some embodiments that can be combined with each of the disclosed embodiments, at least one of two or more tubes includes one or more internal channels or internal ribs that extend outwardly or inwardly from the inner surface of one or more tubes that are twisted around their respective longitudinal directions.

[0028] In some embodiments that can be combined with each of the disclosed embodiments, one or more external ribs extend outwardly from the outer surface of the tubular wall.

[0029] In some embodiments that can be combined with each of the disclosed embodiments, one or more ribs extend inwardly from the inner surface of the tubular wall.

[0030] In some embodiments that can be combined with each of the disclosed embodiments, the heat exchanger also includes a housing disposed outside one or more polymer tube bundles.

[0031] In some embodiments that can be combined with each of the disclosed embodiments, the heat exchanger also includes an outer wrap disposed around one or more polymer tube bundles, the outer wrap being configured to tighten one or more polymer tube bundles such that the tube configuration provides a uniform spacing between the tubes and / or reduces the space between the housing and one or more polymer tube bundles.

[0032] In a further embodiment, a polymer tube-in-tube exchanger having tubes is provided. The heat exchanger comprises one or more polymer tube bundles, at least one of which comprises one or more polymer double-tube structures, each polymer double-tube structure comprising an inner tube, an outer tube, and a plurality of ribs extending from the inner surface of the outer tube to the outer surface of the inner tube, the plurality of ribs being twisted along the longitudinal axis of the polymer double-tube structure.

[0033] In some embodiments that may be combined with each of the disclosed embodiments, the outer tube of the polymer double-tube structure is straight along its respective longitudinal direction.

[0034] In some embodiments that may be combined with each of the disclosed embodiments, the inner tube includes a first tubular wall and a passage configured for the passage of a first fluid, and the outer tube includes a second tubular wall. The space between the inner surface of the second tubular wall of the outer tube and the outer surface of the first tubular wall of the inner tube is configured for the passage of a second fluid.

[0035] In some embodiments that can be combined with each of the disclosed embodiments, one or more polymer double-tube structures have a fixed length.

[0036] In some embodiments that may be combined with each of the disclosed embodiments, the heat exchanger also includes a housing positioned outside one or more polymer tube bundles.

[0037] In some embodiments that may be combined with each of the disclosed embodiments, the heat exchanger also includes an outer wrap positioned around one or more polymer tube bundles, the outer wrap being configured to constrict one or more polymer tube bundles so as to allow the tube configuration to provide uniform spacing between tubes and / or reduce the space between the housing and one or more polymer tube bundles.

[0038] In several embodiments that can be combined with each of the disclosed embodiments, methods are provided for producing one or more polymer tube bundles. The method may include forming polymer tubes by extrusion from polymers. The method may also include twisting one or more polymer tubes to form twisted tubes or subsets of two or more twisted tubes. The method may also include forming bundles of twisted tubes from twisted tubes or subsets of two or more twisted tubes. [Brief explanation of the drawing]

[0039] To illustrate how the advantages and features of this disclosure can be obtained, embodiments shown in the accompanying drawings are referenced. Understanding that these drawings represent only typical embodiments of this disclosure and are not intended to limit its scope, the principles of this specification are described and explained with further specificity and detail using the following accompanying drawings.

[0040] [Figure 1] A schematic diagram of the flow pattern of a conventional tube and shell heat exchanger according to an exemplary embodiment of the present disclosure is shown.

[0041] [Figure 2A] A graph of a conventional twisted-tube metal heat exchanger according to an exemplary embodiment of the present disclosure is shown.

[0042] [Figure 2B] Figure 2A shows an enlarged view of a conventional twisted-tube metal heat exchanger according to an exemplary embodiment of the present disclosure.

[0043] [Figure 3] A perspective view of a twisted-pair heat exchanger bundle according to an exemplary embodiment of the present disclosure is shown.

[0044] [Figure 4] A perspective view of an elliptical / elliptical tube according to an exemplary embodiment of the present disclosure is shown.

[0045] [Figure 5] A perspective view of a peanut-shaped twisted tube according to an exemplary embodiment of the present disclosure is shown.

[0046] [Figure 6] A perspective view of a triangular twisted tube according to an exemplary embodiment of the present disclosure is shown.

[0047] [Figure 7] A perspective view of a petal twist tube according to an exemplary embodiment of the present disclosure is shown.

[0048] [Figure 8] This shows a perspective view of a five-lobed twisted tube according to an exemplary embodiment of the present disclosure.

[0049] [Figure 9] A perspective view of a tube having twisted fins / ribs according to an exemplary embodiment of the present disclosure is shown.

[0050] [Figure 10] A perspective view of a bundle of five-lobed twisted tubes according to an exemplary embodiment of the present disclosure is shown.

[0051] [Figure 11] A perspective view of a bundle of tubes having twisted ribs according to an exemplary embodiment of the present disclosure is shown.

[0052] [Figure 12] A cross-sectional view of an outer wrap applied to a bundle of tubes inside a housing, according to an exemplary embodiment of the present disclosure, is shown.

[0053] [Figure 13] A cross-sectional view of an outer wrap applied to a bundle of tubes having ribs inside the housing, according to an exemplary embodiment of the present disclosure, is shown.

[0054] [Figure 14] A perspective view of a tube having a rifle inside a tube having an internal channel, according to an exemplary embodiment of the present disclosure, is shown.

[0055] [Figure 15] A perspective view of a tube having a rifle inside a tube having internal ribs, according to an exemplary embodiment of the present disclosure, is shown.

[0056] [Figure 16A] A perspective view of a tube-in-tube configuration according to an exemplary embodiment of the present disclosure is shown.

[0057] [Figure 16B] An end section view of a tube-in-tube configuration according to an exemplary embodiment of the present disclosure is shown.

[0058] [Figure 17A] This is a perspective view of a polymer tube-in-shell heat exchanger according to an exemplary embodiment of the present disclosure.

[0059] [Figure 17B] Figure 17A is a side cross-sectional view of a polymer tube-in-shell heat exchanger according to an exemplary embodiment of the present disclosure.

[0060] [Figure 17C] Figure 17A is an end view of a polymer tube-in-shell heat exchanger according to an exemplary embodiment of the present disclosure.

[0061] [Figure 17D] Figure 17B is an enlarged side cross-sectional view of a portion of the polymer tube-in-shell heat exchanger according to an exemplary embodiment of the present disclosure. [Modes for carrying out the invention]

[0062] Figure 1 shows a schematic diagram of the flow pattern of a conventional tube and shell heat exchanger according to an exemplary embodiment of the present disclosure. In the tube and shell heat exchanger 100, a first fluid 104 from tube inlet 108A passes inside tubes 102A-D and exits from tube outlet 108B, while a second fluid 106 from shell inlet 110A passes around tube 102 and along tube 102 through shell 103 and exits from shell outlet 110B. The first fluid 104 is also called the internal fluid that flows inside tubes 102A-D, while the second fluid is also called the external fluid that flows outside tubes 102A-D. The shell inlet 110A is located near tube outlet 108B on a first end 112A, while the tube inlet 108A is located near shell outlet 110B on a second end 112B opposite to the first end 112A. On the shell side of the heat exchanger, the second fluid 106 passes along the tubes 102, and the tube bundles can provide a flow path along the route indicated by arrow 113 to allow the second fluid 106 to enter and exit the tube bundles 102 radially 107. In this way, the bundles of tubes 102A-D guide the external flow of the second fluid 106 adjacent to the tubes 102A-D and reduce bypass. Baffles 112 are used as additional supports for the tubes 102A-D. Baffles 112 also help to improve the distribution of fluid flow within the shell. The heat exchanger 100 may also include tube sheets or perforated header plates 114 at the ends of the tubes 102A-D, which are used to hold the parallel tubes 102A-D with a circular cross-section in place at their ends.

[0063] Although the tube and shell heat exchanger 100 is suitable for high temperatures and pressures, the large spacing between tubes 102A to D causes a lot of flow bypass and insufficient flow distribution, reducing the effectiveness of the tube and shell heat exchanger 100.

[0064] Figure 2A shows a graph representation of a conventional twisted-tube metal heat exchanger according to an exemplary embodiment of the present disclosure. The twisted-tube heat exchanger 200 includes a plurality of twisted tubes 202 enclosed within an enclosure 204.

[0065] Figure 2B shows an enlarged view of the conventional twisted-tube metal heat exchanger of Figure 2A, according to an exemplary embodiment of the present disclosure. As shown in Figure 2B, a single metal tube 202 is twisted to have a wavy pattern along its longitudinal direction. This wavy pattern includes a curve around an axis perpendicular to the longitudinal axis of the tube 202. The twisted-tube metal heat exchanger 200 eliminates baffling and damages tube vibration. The uniquely shaped tubes are arranged on a triangular pattern that provides adjacent support as the fluid swirls freely aligned. The gaps between the tubes 202 facilitate cleaning of the shell side.

[0066] Conventional metal heat exchangers have several problems. Firstly, conventional metal heat exchangers can destroy amines used in carbon recovery applications. Additional applications include all waste heat applications where metal heat exchangers are too expensive to provide recovery, and fluid flows where different viscosities exist, such as water or oil heaters. Other applications include food and beverage applications, as well as acidic solution applications, where metal heat exchangers have problems with chemical resistance.

[0067] To address the problems of conventional twisted-tube metal heat exchangers, this disclosure provides a polymer tube-in-shell heat exchanger having twisted tubes. A non-limiting example of this embodiment is shown in Figure 3. Examples of non-circular tubes are provided in Figures 4-11.

[0068] Figure 3 shows a perspective view of a twisted pair heat exchanger bundle according to an exemplary embodiment of the present disclosure. As shown, the twisted pair heat exchanger bundle 300 includes multiple pairs of tubes 302A and 302B, for example, seven pairs of twisted tubes. Each pair of tubes 302A and 302B is twisted along its longitudinal direction about a longitudinal axis L. Each twisted pair of tubes is in contact with an adjacent twisted pair of tubes. Each tube may have a circular cross-section 304.

[0069] A pair of circular tubes 302A and 302B provide a support and allow a flow path for fluid to enter and / or exit the bundle axially or radially. The open space between the pair of tubes can guide the external fluid along the longitudinal direction of the tubes for effective heat exchange. In addition, the twisted tube pair can generate changes in flow direction along the flow path, which enhances heat exchange by generating additional mixing and turbulence in the external fluid outside the tubes. The viscosity of the external fluid may affect heat exchange. The tubes may also have a small diameter to increase the heat exchange surface and improve heat transfer at the tube surface. Furthermore, the fluid input and output positions can be selected to provide either parallel or counterflow.

[0070] Those skilled in the art will understand that the number of twisted pairs of tubes may vary within a heat exchanger bundle.

[0071] The fluid flows into the twisted tube from the tube ends, which can result in more efficient and reliable performance than conventional shell and tube heat exchangers 100 and 200. The bundle structure within the twisted tube heat exchanger 300 can increase heat transfer and reduce pressure drop, while increasing the heat transfer surface area and eliminating harmful damage. Dead spots may be eliminated. Dead spots are areas where fouling can accumulate and reduce the effective heat transfer surface area. Fouling is the accumulation of undesirable material on a solid surface. The tubes can also be configured so that the size of the tubes and the spacing between them can be tailored to specific applications for controlling the fluid pressure drop both inside and outside the tubes.

[0072] According to a first aspect of the present disclosure, a polymer tube-in-shell heat exchanger having twisted tubes is provided. The heat exchanger comprises one or more polymer tube bundles, each of which comprises at least one tube twisted around its longitudinal direction, or at least one pair of tubes that are twisted or wound around each other.

[0073] According to a second aspect of the present disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which is made up of a pair or other group of tubes wound around each other.

[0074] According to a third aspect of this disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which comprises a plurality of non-circular tubes twisted around their respective longitudinal directions. In such examples, the use of non-circular tubes twisted around their longitudinal direction provides similar performance to that of twisted pair embodiments, but without pairs, thus simplifying the assembly process. The shell-side fluid or external fluid on the outside of the tubes can be arranged to have either axial or radial access to enter and exit the bundle. The gaps between the twisted tubes allow for passages along the tubes that guide the shell-side fluid adjacent to the tubes containing the internal fluid for effective heat exchange between the shell-side fluid and the internal fluid inside the tubes. Furthermore, the twisted non-circular tubes act as supports and baffles. They create further turbulence, thereby increasing heat transfer. The absence of additional supports, baffles, etc. results in tight packaging, compact size, and low weight of the heat exchanger, reducing the overall cost of the unit. Examples of non-circular tubes are provided in Figures 4-11.

[0075] Figure 4 shows a perspective view of an elliptical or elliptical twisted tube according to an exemplary embodiment of the present disclosure. As shown, the twisted tube 400 may have an elliptical or elliptical cross-section 404. The tube 400 is twisted along its longitudinal direction about its longitudinal axis L. The twisted tube 400 has an outer surface 402 which includes twist marks 406, which are compressions of an untwisted tube onto a cylindrical surface.

[0076] Figure 5 shows a perspective view of a peanut-shaped twisted tube according to an exemplary embodiment of the present disclosure. As shown, the peanut twisted tube 500 includes first and second twisted tube sections 502A and 502B connected along its longitudinal axis L. The peanut twisted tube 500 has a peanut-shaped cross section 504 that changes along the longitudinal axis L. The tube 500 also has an outer surface 506 formed by part of the first twisted tube section 502A and part of the second twisted tube section 502B. Inside the outer surface 506 is a hollow portion 505 that allows fluid to pass through.

[0077] Figure 6 shows a perspective view of a triangular twisted tube according to an exemplary embodiment of the present disclosure. The triangular tube 600 may have a triangular cross-section 604 that changes along its longitudinal axis L. The triangular tube 600 is twisted along its longitudinal direction and about its longitudinal axis L. The twisted tube 600 has an outer surface 602 which includes twist marks 606, which are compressions of the triangular surface of an untwisted tube.

[0078] Those skilled in the art will understand that twisted tubes can have cross-sections of any polygon.

[0079] Figure 7 shows a perspective view of a petal twist tube according to an exemplary embodiment of the present disclosure. The petal twist tube 700 includes four tubes 702A-D whose outer portions are connected and whose inner portions are removed to form a single tube. The petal twist tube 700 is twisted along its longitudinal direction about its longitudinal axis L. The petal twist tube 700 includes an outer shell 706 having a petal-shaped cross-section that changes along the longitudinal axis L. The inner shell 706 is a hollow portion 704 that allows fluid to pass through.

[0080] Figure 8 shows a perspective view of a five-lobed twisted tube according to an exemplary embodiment of the present disclosure. The five-lobed twisted tube 800 includes five half-tubes 802A-E, whose outer portions are connected and whose inner portions are removed to form a single tube. The five-lobed twisted tube 800 is twisted along its longitudinal direction about its longitudinal axis L. The five-lobed twisted tube 800 includes a shell 806 having a five-lobed cross-section 804 that changes along the longitudinal axis L. The inner shell 806 is a hollow portion 805 that allows fluid to pass through.

[0081] Figure 9 shows a perspective view of a tube having twisted fins / ribs according to an exemplary embodiment of the present disclosure. As shown, a first twisted tube 902A is twisted along its longitudinal direction about its longitudinal axis L. The first twisted tube 902A includes three ribs or fins 906A-C that extend outward beyond the circular shell 908 and increase the surface area for heat exchange. The surface area for heat exchange increases with the height of the ribs or fins. The ribs 906A-C may be arranged at equal intervals along the circular cross section 904. A second twisted tube 902B is also twisted along its longitudinal direction about its longitudinal axis L. The second twisted tube 902B includes one rib 906D. Furthermore, a third twisted tube 902C is also twisted along its longitudinal direction about its longitudinal axis L. The third twisted tube 902C includes two ribs 906E-F that are opposite each other from the center of the circular cross-section 904. The spacing 914 between the fins or ribs 902 along the longitudinal axis may differ for different twisted tubes. In addition to providing an additional heat transfer surface area, the twisted ribs allow the tubes to stand upright within the tube bundle and enable control of the tube spacing for an improved flow distribution of the external fluid that passes through the shell 908 along the outside of the tubes, also improving heat transfer.

[0082] Figure 10 shows a perspective view of a bundle of pentagonal twisted tubes according to an exemplary embodiment of the present disclosure. The bundle of twisted tubes 1000 comprises a plurality of pentagonal twisted tubes 800. Each pentagonal twisted tube 800 is in contact with its adjacent pentagonal twisted tube 800.

[0083] Figure 11 shows a perspective view of a bundle of tubes having twisted ribs according to an exemplary embodiment of the present disclosure. The bundle of twisted tubes 1100 comprises a plurality of tubes having twisted ribs. Each tube 900 having a rib is in contact with an adjacent tube 900 having a rib. The use of external ribs or fins helps improve heat transfer by providing additional surface area. In some modifications, the tubes may have internal ribs or fins that also help improve heat transfer by providing additional surface area. In addition to providing additional heat transfer surface area, the twisted ribs allow the tubes to stand upright within the tube bundle and control the tube spacing for an improved flow distribution of external fluid that passes through the shell 908 along the outside of the tubes and also improves heat transfer.

[0084] The shape and size of the tubes can be customized to control the cross-sectional area ratio suitable for fluids with various viscosities and thermal conductivity in order to improve heat exchange and control pressure drop.

[0085] The twisted tube bundle also provides the ability to control the uniformity of the intermediate space in order to generate good flow distribution and bypass control.

[0086] Figure 12 illustrates a cross-sectional view of an outer wrap applied to a bundle of tubes inside a housing according to an exemplary embodiment of the present disclosure. The polymer heat exchanger 1200 includes a housing 1202 and an outer wrap 1204 that wraps around a bundle of tubes 1206 and tightens the bundle. The bundle of tubes 1206 with the outer wrap is placed inside the housing 1202. The outer wrap 1204 provides compression of the tube bundle to bring the tubes into contact with each other and thus helps to eliminate bypass paths along the inner surface of the shell. The outer wrap also helps to control the bypass of flow between tubes in the bundle. Due to variations in pipe dimensions, a space may exist between the bundle of tubes and the housing 1202. The outer wrap helps to fill the space between the outer surface of the bundle of tubes 1206 and the housing 1202 and thus has control of flow bypass. Most of the tubes 1206 may be in contact with each other, but there may still be a space 1208 between the tubes 1206.

[0087] Figure 13 illustrates a cross-sectional view of an outer wrap applied to a bundle of tubes having ribs on the inside of a housing, according to an exemplary embodiment of the present disclosure. The polymer heat exchanger 1300 includes a housing 1302 and an outer wrap 1304 that wraps around a bundle of tubes 1306 having ribs 1308 and tightens the bundle. The bundle of tubes 1306 with the outer wrap 1304 is placed inside the housing 1302. The outer wrap 1304 provides compression of the tube bundle to bring the tubes 1306 into contact with each other and thus helps eliminate bypass paths along the inner surface of the shell. Most of the tubes 1306 may be in contact with each other, but there may still be spaces 1310 between the tubes 1306.

[0088] In some variations, the outer wrap may be formed from a stretchable woven fabric.

[0089] In some variations, the housing may be a rigid plastic pipe such as PVC or polypropylene.

[0090] In some variations, the housing may be made of fiberglass-reinforced plastic pipe.

[0091] In some variations, the tube may have ribs on the outside.

[0092] Figure 14 illustrates a perspective view of a tube having a rifle inside an internal channel, according to an exemplary embodiment of the present disclosure. As shown, the polymer tube 1400 includes three channels 1402 extending outward from the inner surface 1406 of a tubular wall 1404 that is twisted around each longitudinal direction along the longitudinal axis L. The number of channels may vary. The internal channels 1402 appear as a helical curve when viewed from the end, as indicated by the dashed lines. The internal channels 1402 can improve surface exposure and / or turbulence for improved heat exchange.

[0093] Figure 15 illustrates a perspective view of a tube having ribs inside a tube with internal ribs, according to an exemplary embodiment of the present disclosure. As shown, the polymer tube 1500 includes three internal ribs 1502 extending outward from the inner surface 1506 of a tubular wall 1504 that is twisted around each longitudinal direction along the longitudinal axis L. The number of ribs may vary. The internal ribs 1502 appear as a helical curve when viewed from the end, as indicated by the dashed lines. The internal ribs 1502 can improve surface exposure and / or turbulence for improved heat exchange.

[0094] Figure 16A illustrates a perspective view of a tube-in-tube configuration according to an exemplary embodiment of the present disclosure. Figure 16B illustrates an end section view of a tube-in-tube configuration according to an exemplary embodiment of the present disclosure. As shown, the polymer double-tube structure 1600 includes an outer tube 1602 and an inner tube 1604. The dual-tube structure 1600 also includes a rib 1606 between the outer tube 1602 and the inner tube 1604 to indicate and control the position of the inner tube. The rib 1606 extends from the inner surface 1608 of the outer tube 1602 to the outer surface 1610 of the inner tube 1604. For example, the dimensions of this rib control the space between the inner and outer tubes. The rib 1606 of the double-tube structure is twisted around its respective longitudinal direction along the longitudinal axis L. This allows the double-tube structure 1600 to have an annular flow of a first fluid in the space 1612 between the inner and outer tubes. The double-tube structure 1600 allows for a second fluid flow inside the hollow portion 1614 of the inner tube. The surfaces of the tubes 1600 (e.g., the outer surface 1609 and inner surface 1608 of the outer tube 1602, and the inner surface 1611 and outer surface 1610 of the inner tube 1604) and the ribs 1606 may be straight or twisted. The double-tube structure 1600 may be for a tube bundle in which the double-tube structures 1600 are in contact with each other.

[0095] Figure 17A is a perspective view of a polymer tube-in-shell heat exchanger according to an exemplary embodiment of the present disclosure. Figure 17B is a side cross-sectional view of the polymer tube-in-shell heat exchanger of Figure 17A according to an exemplary embodiment of the present disclosure. Figure 17C is an end view of the polymer tube-in-shell heat exchanger of Figure 17A according to an exemplary embodiment of the present disclosure. Figure 17D is an enlarged side cross-sectional view of a portion of the polymer tube-in-shell heat exchanger of Figure 17B according to an exemplary embodiment of the present disclosure. As shown, the polymer tube-in-shell heat exchanger 1700 includes a housing 1712, an inlet housing 1702A, and an outlet housing 1702B for the shell fluid 1703 to flow through the housing 1712 and between the tubes 1708. The polymer tube-in-shell heat exchanger 1700 also includes inlets 1704A and outlets 1704B for the tube fluid 1706 to flow through the tubes 1708. The outlet housing 1702B for the shell fluid 1703 is close to the inlet 1704A for the tube fluid 1706, while the inlet housing 1702A for the shell fluid 1703 is close to the outlet 1704B for the tube fluid 1706 so that the shell fluid 1703 flows back with the tube fluid 1706 to increase the efficiency of heat exchange. Also, the tubes 1708 are in contact with each other. As shown in Figures 3-15, the tubes or ribs inside the tubes can be twisted. The shell fluid 1703 can fill the space between the tubes.

[0096] The polymer tube-in-shell heat exchanger 1700 also includes an outer lap layer 1710, which includes a potting material such as epoxy, polyurethane, or any other suitable material to fill the space around the tube 1708 and seal the inner walls of the tube 1708 and the housing 1712. The inlet 1704A includes a connection 1714 configured to mate on the outside of the housing 1712. Similarly, the outlet 1704B includes a connection 1714 configured to mate on the outside of the housing 1712. The inlet housing 1702A and the outlet housing 1702B also include a connection 1716 configured to mate on the outside of the housing 1712.

[0097] [Method for manufacturing polymer twisted tubes] Polymer tubes or plastic tubes can be manufactured by extrusion molding. Polymer tubes may be made to have ribs or fins, and then the polymer tubes may be twisted.

[0098] In some variations, the polymer tube may be twisted immediately after extrusion while it is still soft and easily twisted.

[0099] In some variations, the polymer tubing may be supplied by the supplier. The polymer tubing may be heated to a sufficiently soft consistency without losing its shape for twisting.

[0100] In some variations, the polymer tube may be extruded without torsion so that it has the shape shown in Figures 3-15 and 16A-B. Torsion is provided by extrusion without a subsequent torsion process.

[0101] In some variations, two or more polymer tubes are twisted together along their longitudinal directions. The twisted pairs or other polymer tubes can then be bundled together.

[0102] In some variations, a single polymer tube having fins or ribs can be twisted along its longitudinal direction. The twisted polymer tubes can then be bundled together.

[0103] [Experiment with a twisted-tube heat exchanger] A twist-tube plastic heat exchanger containing 60 twisted tubes was assembled from polyetheretherketone (PEEK) tubing. As shown in Figure 9, the PEEK tubing had an outer diameter of 1.5 mm and an inner diameter of 1.3 mm with spiral ribs. Each pair of the 60 tubes was twisted together 55 times. Water was supplied from a tank to the heat exchanger. Chilled water was supplied to the heat exchanger in the opposite direction to the hot water to create a counterflow within the heat exchanger. Pressure drop was measured using vertical tubing. Temperature was measured using thermocouples.

[0104] At a flow rate of 210 mL / min, a pressure drop of 0.08 psi occurred on the cold side (or shell side), and a pressure drop of 0.21 psi occurred on the hot side (tube). The cold water was heated from 16°C to 76°C. The hot water was cooled from 79°C to 21°C. The heat transfer coefficients were calculated for both sides of the heat exchange.

[0105] Table 1 lists a comparison between the disclosed polymer high-density packed tube-in-shell heat exchanger and a metal tube and shell heat exchanger. As shown in Table 1, the disclosed polymer high-density packed tube-in-shell heat exchanger is more effective than a metal tube and shell heat exchanger, for example, having about 80% effectiveness.

[0106] Furthermore, in typical tube and shell heat exchangers with crossflow, such as metal tube and shell heat exchangers, the high-temperature shell fluid is much hotter than the low-temperature fluid. The flow velocity is also higher, and therefore the temperature change is lower than that of the low-temperature fluid. This does not result in a temperature "crossover," meaning the high-temperature fluid outlet temperature is higher than the low-temperature fluid outlet temperature. This effect is a high logarithmically mean temperature difference (LMTD). In the case of heat recovery heat exchangers, it is desirable to recover as much heat as possible and keep the LMTD to a minimum, thereby allowing the low-temperature fluid outlet temperature to be higher than the high-temperature fluid outlet temperature. The disclosed polymer heat exchanger with counterflow can achieve a low LMTD.

[0107] Furthermore, the disclosed polymer high-density packed tube-in-shell heat exchanger has a significantly higher surface area packing density than metal tube and shell heat exchangers, and is less expensive than metal tube and shell heat exchangers. [Table 1: Comparison of two heat exchangers] [Table 1]

[0108] The tubular shape of the tube provides better structural strength compared to sheet / plate heat exchangers. Furthermore, the tube is economical to manufacture by extrusion molding. Polymer tubes have thin walls to obtain low thermal resistance. In addition, the small diameter and low hydraulic diameter on both sides, i.e., the shell side (outside of the tube) and the tube side (inside of the tube), provide high heat transfer at the surface of the tube. The use of smooth polymer tubes can result in low pressure loss, low fouling, and easy cleaning of the exchanger. In addition, the use of polymer materials provides high chemical resistance.

[0109] Furthermore, twisted tube bundles, in particular, do not have additional supports such as baffles, resulting in tight packaging of the heat exchanger, a smaller size, lighter weight, and reduced overall cost.

[0110] According to a fourth aspect of the present disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which comprises a plurality of elliptical or oval tubes twisted around their respective longitudinal directions.

[0111] According to a fifth aspect of the present disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which comprises a plurality of peanut-shaped twisted tubes twisted around their respective longitudinal directions.

[0112] According to a sixth aspect of the present disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which comprises a plurality of triangular or other polygonal twisted tubes twisted around their respective longitudinal directions.

[0113] According to a seventh aspect of the present disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which comprises a plurality of petal-twisted tubes twisted around their respective longitudinal directions.

[0114] According to an eighth aspect of the present disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which comprises a plurality of 5-lobed twisted tubes twisted around their respective longitudinal directions.

[0115] According to a ninth aspect of the present disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which comprises a plurality of tubes having twisted fins / ribs.

[0116] According to a tenth aspect of the present disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which comprises a plurality of 5-lobed twisted tubes.

[0117] According to an eleventh aspect of the present disclosure, the heat exchanger comprises one or more polymer tube bundles, each of which comprises a plurality of twisted rib tubes.

[0118] Because metal heat exchangers destroy amines used in carbon recovery, the polymer tube-in-shell heat exchanger of this disclosure, having twisted tubes, may be particularly suitable for carbon recovery applications. Additional applications include all waste heat applications where metal heat exchangers would be prohibitively expensive to provide payback, as well as fluid flows where different viscosities exist, such as water / oil heaters. Other applications include food and beverage applications, as well as acid solution applications where the use of polymer tubes offers advantages over metal heat exchangers.

Claims

1. A polymer tube-in-shell heat exchanger having twisted tubes, One or more polymer tube bundles, wherein at least one of the one or more polymer tube bundles includes one or more sets of two or more tubes that are twisted or wound around one or more tubes, each tube comprising a tubular wall and a passage configured for the flow of a first fluid, and the heat exchanger is configured such that a second fluid passes through the space between the twisted tubes, An outer wrap disposed around one or more polymer tube bundles, the outer wrap configured to control the bypass of the second fluid between the twisted tubes and to tighten the one or more polymer tube bundles so as to allow the tube configuration to provide uniform spacing between the tubes and / or reduce the space between the housing and the one or more polymer tube bundles, A heat exchanger equipped with [a specific feature].

2. The heat exchanger according to claim 1, wherein one or more sets of the two or more tubes have a fixed length.

3. The heat exchanger according to claim 1, wherein the one or more polymer tube bundles include a plurality of pairs of tubes that are twisted or wrapped around each other.

4. The heat exchanger according to claim 1, wherein the one or more polymer tube bundles include a plurality of three or more tubes that are twisted or wrapped around each other.

5. The heat exchanger according to claim 1, wherein the one or more polymer tube bundles include a plurality of non-circular tubes, each tube being twisted around its respective longitudinal direction.

6. The heat exchanger according to claim 1, wherein one or more polymer tube bundles include elliptical tubes twisted around their respective longitudinal directions.

7. The heat exchanger according to claim 1, wherein one or more polymer tube bundles include peanut-shaped twisted tubes twisted around their respective longitudinal directions.

8. The heat exchanger according to claim 1, wherein one or more polymer tube bundles include polygonal twisted tubes twisted around their respective longitudinal directions.

9. The heat exchanger according to claim 1, wherein one or more polymer tube bundles include petal-twisted tubes twisted around their respective longitudinal directions.

10. The heat exchanger according to claim 1, wherein one or more polymer tube bundles include leaflet twisted tubes twisted around their respective longitudinal directions.

11. The heat exchanger according to claim 1, wherein two or more polymer tubes include one or more external ribs extending outward from the outer surfaces of the two or more twisted tubes, each tube around its respective longitudinal direction.

12. The heat exchanger according to claim 1, wherein the two or more tubes each have one or more internal channels or internal ribs extending outward or inward from the inner surface of one or more of the tubes that are twisted around their respective longitudinal directions.

13. The heat exchanger according to claim 1, further comprising a housing disposed on the outside of one or more polymer tube bundles.

14. A polymer tube-in-shell heat exchanger having twisted tubes, One or more polymer tube bundles, wherein at least one of the one or more polymer tube bundles includes a plurality of polymer tubes, The bundle comprises an outer wrap arranged around one or more polymer tube bundles, Each tube comprises a tubular wall and a passage configured for the flow of a first fluid, and the heat exchanger is configured such that a second fluid passes through the space between the twisted tubes. At least one of the plurality of polymer tubes is provided with one or more ribs extending from a tubular wall that is twisted around its longitudinal direction, A heat exchanger in which the outer wrap is configured to control the bypass of the second fluid between the twisted tubes and to tighten the one or more polymer tube bundles so as to allow the tube configuration to provide uneven spacing between the tubes and / or reduce the space between the housing and the one or more polymer tube bundles.

15. The heat exchanger according to claim 14, wherein the plurality of polymer tubes have a fixed length.

16. The heat exchanger according to claim 14, wherein the one or more polymer tube bundles include a plurality of non-circular tubes, each tube being twisted around its respective longitudinal direction.

17. The heat exchanger according to claim 14, wherein one or more polymer tube bundles include elliptical tubes twisted around their respective longitudinal directions.

18. The heat exchanger according to claim 14, wherein one or more polymer tube bundles include peanut-shaped twisted tubes twisted around their respective longitudinal directions.

19. The heat exchanger according to claim 14, wherein one or more polymer tube bundles include polygonal twisted tubes twisted around their respective longitudinal directions.

20. The heat exchanger according to claim 14, wherein one or more polymer tube bundles include petal-twisted tubes twisted around their respective longitudinal directions.

21. The heat exchanger according to claim 14, wherein one or more polymer tube bundles include leaflet twisted tubes twisted around their respective longitudinal directions.

22. The heat exchanger according to claim 14, wherein at least one of the two or more tubes comprises one or more internal channels or internal ribs extending outward or inward from the inner surface of one or more of the tubes that are twisted around the longitudinal direction of each of them.

23. The heat exchanger according to claim 14, wherein one or more of the external ribs extend outward from the outer surface of the tubular wall.

24. The heat exchanger according to claim 14, wherein one or more ribs extend inward from the inner surface of the tubular wall.

25. The heat exchanger according to claim 14, further comprising a housing disposed on the outside of one or more polymer tube bundles.

26. A polymer tube-in-tube heat exchanger having a tube, wherein the heat exchanger is One or more polymer tube bundles, wherein at least one of the one or more polymer tube bundles includes one or more polymer double tube structures, each polymer double tube structure includes an inner tube, an outer tube, and a plurality of ribs extending from the inner surface of the outer tube to the outer surface of the inner tube, and the plurality of ribs are twisted along the longitudinal axis of the polymer double tube structure. A heat exchanger equipped with [a specific feature].

27. The heat exchanger according to claim 26, wherein the outer tube of the polymer double-tube structure is straight along its respective longitudinal direction.

28. The heat exchanger according to claim 26, wherein the inner tube comprises a first tubular wall and a passage configured for the passage of a first fluid, and the outer tube comprises a second tubular wall and a space configured for the passage of a second fluid between the inner surface of the second tubular wall of the outer tube and the outer surface of the first tubular wall of the inner tube.

29. The heat exchanger according to claim 26, wherein one or more polymer double-tube structures have a fixed length.

30. The heat exchanger according to claim 26, further comprising a housing disposed on the outside of one or more polymer tube bundles.

31. The heat exchanger according to claim 26, further comprising an outer wrap disposed around one or more polymer tube bundles, wherein the outer wrap is configured to tighten the one or more polymer tube bundles so as to allow the tube configuration to provide uniform spacing between tubes and / or reduce the space between the housing and the one or more polymer tube bundles.

32. A method for producing one or more polymer tube bundles according to any one of claims 1 to 31, Forming polymer tubes by extrusion from polymers, Twisting one or more polymer tubes to form a twisted tube or a subset of two or more twisted tubes, Forming a bundle of twisted tubes from the aforementioned twisted tube or a subset of two or more twisted tubes, Methods that include...

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