HEAT EXCHANGER AND METHOD FOR SUPPORTING A BUNDLE OF PIPE IN A HEAT EXCHANGER

Description

FIELD

[0001] The present invention relates to a heat exchanging apparatus, also denoted "heat exchanger", a method of use and a method of manufacturing, and more particularly to embodiments providing a plurality of bundled round heat exchange tubes comprising individually segmented sections generally having a twisted configuration capable of operably self-supporting the respective tubes within the heat exchanger.CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present application claims priority to U.S. Provisional Patent Application No. 62 / 660089 titled "Tube Bundle for Heat Exchanger and Method of Supporting Same within Heat Exchanger Shell" filed on April 19, 2018.BACKGROUND

[0003] Tubular heat exchangers, including shell-and-tube and hairpin (multitube) type heat exchangers, are used in a wide variety of applications to create heat exchange between streams of various fluids. Such heat exchangers generally include a combination, or bundle, of tubes housed within a cylindrically shaped shell. In operation, a first fluid, commonly referred to as the "tube-side fluid," is directed through at least some of the tubes of the tube bundle. Concurrently, a second fluid, commonly referred to as the "shell-side fluid," is directed within the shell and into any void around the tubes comprising the tube bundle, wherein the tube wall of each tube can permit heat exchange between the tube-side fluid stream flowing within the tubes and the shell-side fluid stream flowing around the tubes.

[0004] Generally, the tube bundle of a tubular heat exchanger includes a plurality of separate, self-contained individual tubes that extend in parallel to each other, wherein one or both of the ends of each respective tube is fixed to a header plate or a plurality of header plates, which are known as tube sheets. In applications that demand generally elongated heat exchangers of various lengths, known tubes and tube bundles, and the various designs thereof, of tubular heat exchangers, including shell-and-tube or hairpin (multitube) type heat exchangers, are subject to sagging and vibrations, both of which can negatively affect the heat exchanger and its components. To mitigate the negative effects of tube sagging and vibration, known tubes and tube bundles of tubular heat exchangers require intermediate support structures or members at various points over the length of the tubes or tube bundle. Such intermediate support structures or members can include spaced-apart baffles (e.g., segmented baffles), which generally consist of plates having holes or openings to receive and support the tubes and may further include spaces or voids for permitting the flow of shell-side fluid. In addition to supporting the tubes and maintaining the desired position of the same within the shell, such baffles may generally redirect the flow of the shell-side fluid, such that it flows across, rather than along, the tubes. In this way, such baffles generally inhibit the flow of the shell-side fluid along the length of the tubes. Other types of supports can consist of grids or rods.

[0005] Although baffles designs can vary and have any number of configurations and features to suit a particular application, baffle positioning and spacing can pose a difficult design challenge and create an impediment to efficient and optimal heat exchanger operation. In particular, when the spacing between a series of baffles is reduced to address the sagging and vibration of a specific tube or tube bundle, the limited space between the baffles can adversely affect the heat exchanger by reducing the flow area for the shell-side fluid, which results in excessive shell-side pressure drop.

[0006] Apart from tubular heat exchangers having spaced-apart baffles, also heat exchangers having deformed twisted tubes are known from the prior art.

[0007] EP 2 149 770 A2, for example, discloses a heat exchanger having deformed tube sections. The deformed tube sections are distributed over the whole length of the tube-shell heat exchanger. As a consequence, the main vertices of the deformed tube sections make contact to the outer circumferential surfaces adjacent undeformed tube sections.

[0008] US 4 589 481 A describes a tube heat exchanger with a plurality of tubes, wherein each of the tubes is continuously twisted along its whole length and wherein the twisted tubes make contact to each other at regular intervals.

[0009] GB 2 213 922 A is directed to a heat exchanger consisting of a bundle of close-packed parallel tubes. Each tube is of elliptical external shape and the orientation of the ellipse varies helically along the length of the heat exchanger.

[0010] SU 1 322 064 A1 teaches a shell-and-tube heat exchanger which contains heat exchanging tubes, wherein the heat exchanging tubes are oval and screw-shaped in swirling sections and wherein the swirling sections are separated by straight sections.

[0011] However, there still is a need in the art for an improved design for a tube, a tube bundle, and a heat exchanger that can effectively support the tube or the tube bundle within the shell for use in connection with low shell-side pressure drop designs or applications, while also avoiding sagging and vibration of the tubes.

[0012] This need has been satisfied by providing the heat exchanging apparatus with the features of independent claim 1 and a method of manufacturing a heat exchanging apparatus with the features of claim 14. Furthermore, the method of carrying out heat exchange according to claim 12 helps to improve heat-exchanging processes. Preferred embodiments of the heat exchanging apparatus and the methods are covered by the dependent claims.FIGURES

[0013] FIGURE 1 is a perspective view of an exemplary heat exchanger in accordance with embodiments presented herein; FIGURE 2 is a partial side elevation schematic representation of an exemplary heat exchanger in accordance with embodiments presented herein; FIGURE 3 is a partial detail side representation of tube sections of a heat exchanger in accordance with embodiments presented herein; FIGURE 4 is a cross-sectional representation taken generally along line 4-4 of FIG. 3 in the direction of the arrows and showing a tube bundle in accordance with the embodiment shown in FIG. 3; FIGURE 5 is a cross-sectional representation taken generally along line 5-5 of FIG. 3 in the direction of the arrows and showing a tube bundle in accordance with the embodiment shown in FIG. 3; FIGURE 6 is a cross-sectional representation taken generally along line 6-6 of FIG. 3 in the direction of the arrows and showing a tube bundle in accordance with the embodiment shown in FIG. 3; FIGURE 7 is a cross-sectional representation taken generally along line 7-7 of FIG. 3 in the direction of the arrows and showing a tube bundle in accordance with the embodiment shown in FIG. 3; FIGURE 8 is a cross-sectional representation taken generally along line 8-8 of FIG. 3 in the direction of the arrows and showing a tube bundle in accordance with the embodiment shown in FIG. 3; FIGURE 9 is a cross-sectional representation taken generally along line 9-9 of FIG. 3 in the direction of the arrows and showing a tube bundle in accordance with the embodiment shown in FIG. 3; and FIGURE 10 is a cross-sectional representation taken generally along line 10-10 of FIG. 3 in the direction of the arrows and showing a tube bundle in accordance with the embodiment shown in FIG. 3. DETAILED DESCRIPTION

[0014] Embodiments presented herein are generally directed to a heat-exchanging apparatus, also denoted "heat exchanger", a method of manufacture and a method of carrying out heat exchange providing segmented twisted sections of bundled heat exchange tubes. Embodiments disclosed herein can be provided or practiced with any number of exemplary heat exchanger designs, including for example a shell-and-tube or hairpin (multitube) type heat exchanger or multi-pass arrangements, and / or designs implementing parallel (co-current) or counter-flow arrangements.

[0015] With reference to the drawings, FIG. 1 schematically depicts a perspective illustration of a heat exchanger 100 according to an exemplary embodiment of the present invention. As best illustrated in FIG. 1, a tubular heat exchanger 100 can be generally elongated and comprise an inlet 102, an outlet 104, and tubes 120 or a tube bundle 140. The tubular heat exchanger 100 of FIG. 1 is depicted without a shell or other common heat exchanger components (e.g., a shroud, and so on). However, it will be understood that heat exchanger 100 may comprise such components without limitation.

[0016] FIG. 2 representatively illustrates a partial side schematic representation view of a heat exchanger 100 according to an exemplary embodiment provided herein, and more particularly to an exemplary bundle 140 of individual tubes 120 having a generally U-shaped arrangement. As shown in FIG. 2, the U-shaped bundle 140 of tubes 120 can comprise a plurality of generally elongated tubes 120 having at least a first leg portion 142 and a second leg portion 144 extending substantially parallel to each other along their lengths. According to the embodiment illustrated in FIG. 2, it will be recognized that portions 142, 144 of tubes 120 within the tube bundle 140 are in fluid communication with each other so that tube-side fluid within an interior passageway of the tubes can be permitted to flow in a first direction along the first leg portion 142 of a U-shaped tube 120 from an inlet 102 and into the U-shaped portion 146, where the tube-side fluid can reverse direction and flow back in a second direction, opposite to the first direction, along the second leg portion 144 of a U-shaped tube 120 to an outlet 104.

[0017] Although FIG. 2 depicts the tube bundle 140 generally comprising a linear first leg portion 142 and a linear second leg portion 144 that are joined by a generally U-shaped portion 146, it will be understood that the tube bundle 140 can comprise any of a number of shapes, whether presently known or later developed, including, without limitation, generally triangular shapes, generally rectangular shapes, and any similar symmetrical and non-symmetrical shapes or series of shapes that are joined by any number of rounded portions that have varying arc lengths and radius sizes. Further, a preferred embodiment of the present invention can be used with alternate tube bundle arrangements including, for example, straight tube or shell arrangements, single or multi-pass arrangements, and / or designs implementing parallel (co-current) or counter-flow arrangements.

[0018] As shown schematically in FIG. 2, according to exemplary embodiments the fluid tubes 120 of the tube bundle 140 can generally comprise an alternating series of individually segmented sections 150, in fluid communication with each other, comprising generally tubular straight sections 152 and sections further generally comprising a twisted configuration 154, which are twisted or rotated along their lengths about the respective central longitudinal axes 160 defined thereby. For example, FIG. 2 illustrates the first leg portion 142 and the second leg portion 144 of each tube 120 as having four straight sections 152 and three twisted sections 154 along their lengths, including (in sequence, from left to right): a first straight section 152, a first twisted section 154, a second straight section 152, a second twisted section 154, a third straight section 152, a third twisted section 154, and a fourth straight section 152 leading into the U-shaped portion 146. Thus, each tube 120 of the tube bundle 140 is shown as providing a series 150 of intermittent twisted sections 154 spaced apart by straight or untwisted tube sections 152. However, it will be understood that a preferred embodiment of the present invention can comprise a first straight section 152, generally corresponding with the entire length of the first leg portion 142, and a first twisted section 154, generally corresponding with the entire length of the second leg portion 144, or any variation thereof. Further, although FIG. 2 depicts the alternating series of individually segmented sections 150 as being generally equal or consistent in length, it will be understood that the length of any straight section 152 or any twisted section 154 can vary relative to any other straight section 152 or twisted section 154. According to exemplary embodiments as shown schematically in FIG. 2, the twisted tube sections 154 of the plurality of tubes can be generally positioned in alignment with one another and the straight tube sections 152 can be generally positioned in alignment with one another.

[0019] As shown schematically in Fig. 2, in a preferred embodiment, the intermittent twisted sections 154 of the first leg portion 142 and the intermittent twisted sections 154 of the second leg portion 144 of each tube 120 within the tube bundle 140 can be aligned so that the twisted sections 154 of each leg portion are generally laterally adjacent to the twisted sections 154 of the other leg portion. Although FIG. 2 illustrates a specific number and location of alternating twisted sections 154 and straight sections 152, it will be understood that embodiments are not limited to such and that such alternating sections 150 can be provided in alternative numbers or locations, without limitation.

[0020] The twisted sections 154, interspersed between straight sections 152, are advantageous because they can generally result in a more efficient conversion of pressure drop across the shell-side of the tubes 120 and the tube bundle 140. Specifically, the twisted sections 154, and the arrangement thereof, can mitigate the negative effects of tube sagging and vibration of the tubes 120, because the twisted sections 154, and the arrangement thereof, increases the mechanical resonant frequency of the tube 120, which can make the tubes 120 and any bundle 140 of such tubes 120 more resistant to lateral deflection from forces generated by shell-side fluid flow through the heat exchanger 100. In this way, the twisted sections 154, and the arrangement thereof with straight sections 152, eliminate the need for closely-spaced intermediate support structures or members at various points along the length thereof and, in some instances, the need for intermediate support structures or members at all. The improvement being advantageous over tubes, arrangements of tubes, and tube bundles that comprise either entirely straight tubes or tubes that are twisted over their entire lengths, without the alternating series of individually segmented straight sections and twisted sections 150. Further, the twisted sections 154 can promote the efficiency of heat transfer between tube-side fluid and shell-side fluid when compared to known tube arrangements. First, by eliminating the need for closely-spaced intermediate support structures or members at various points on the length of the tube 120 or tube bundle 140, such configuration requires less baffles, or even no baffles, to support and maintain the tubes 120 or the tube bundle 140, which reduces the inhibiting effect of such baffles on the flow of the shell-side fluid along the length of the tubes. Second, by eliminating the need for closely-spaced intermediate support structures or members at various points on the length of the tube 120 or tube bundle 140, such configuration does not create the excessive shell-side pressure drop common to known configurations and spacings of baffles used in heat exchangers.

[0021] FIG. 3 representatively illustrates a partial detail representation of the side of a twisted section 154 of three (3) tubes 120 of a tube bundle 140 according to exemplary embodiment. FIGS. 4-10 further depict representations of the various cross-sections at specific rotational intervals along the length of a segment S of the respective tubes 120 in FIG. 3. As best shown in FIGS. 3-10, between segment S, each tube 120 is twisted or rotated about a central longitudinal axis 160 at least 360°, or one complete revolution, with each cross-section view along segment S showing rotation on the order of approximately 60° from any immediately adjacent cross-section. In a preferred embodiment, the segment S can be approximately between three (3) inches and sixteen (16) inches, or approximately between five (5) inches and ten (10) inches, depending on the diameter of the respective tube 120, which can vary between approximately 0.625 inches in diameter and one (1) inch in diameter. In a preferred embodiment, each tube 120 can complete two 360° turns between any two consecutive straight sections 152. As shown schematically in FIG. 3, the exterior surfaces of tubes 120 avoid contact along the straight sections 152.

[0022] FIGS. 4-10 schematically illustrate rotation of tubes 120 within a tube bundle 140 through a 360° portion of rotation along the twisted section 154. Although the tubes 120 according to exemplary embodiments presented herein are generally provided as having a round cross-section profile when oriented along the straight sections, FIGS. 4-10 show that such round cross-sectional profile is compressed through the twisting of the tube bodies. According to exemplary embodiments, such compression can flatten the round-cross sectional profile such that the tubes take on a generally elliptical shape as shown in FIGS. 4-10. Such compression can reduce the cross-sectional area of the tubes and causes opposing points on the sides of the tubes to protrude outward. As shown schematically in FIGS 4-10, such protrusion can bring about contact 170 between exterior surfaces of tube bodies of adjacent tubes.

[0023] As shown schematically in FIGS. 4-10, exterior surfaces of adjacent tubes 120 of the tube bundle 140 can have a plurality of points of contact 170 along the twisted section at certain rotation intervals. According to exemplary embodiments shown in FIGS. 4-10, rotation of the tube body of each of the plurality of tubes 120 in the twisted section can be synchronized such that the tubes 120 rotate together. For example, at commencement of a twisted section as shown representatively in FIG. 4, the plurality of tubes 12 can be in an initial rotation orientation. From this orientation, as the tubes twist along the twisted segment, the tube body of each tube rotate together (tubes shown as being horizontally adjacent to one another in FIG. 4 with their end points in contact are shown as rotating counterclockwise towards the rotation interval shown in FIG. 5). In undergoing such rotation, the tubes shown as being in contact with one another in FIG. 4 taper away from one another and form new contacts (with another tube) at the rotation interval of FIG. 5. Such contact and separation continues as the tubes rotate through the twisted section. It will be recognized that FIG. 7 represents a rotation interval taken on the order of 180° from the initial rotation orientation of FIG. 4. Accordingly, the right side of a tube in FIG. 4 would be shown as being the left side in FIG. 7.

[0024] Each of FIGS. 4-10 show tubes 120 of an exemplary tube bundle 140 at a particular rotation interval taken on the order of 60° through a full 360° of rotation of a twisted segment. For example, with respect to an interior tube of the tube bundle 140 in FIG. 4 which is surrounded by adjacent perimeter tubes, such interior tube 120 can have a first point of contact 170 with an adjacent tube 120 directly to its right and a second point of contact 170 with the adjacent tube 120 directly to its left. In FIG. 5, the centermost tube has the first point of contact 170 with the adjacent tube 120 to its upper-right and the second point of contact 170 with the adjacent tube 120 to its lower-left. In FIG. 6, the centermost tube 120 has the first point of contact 170 with the adjacent tube 120 to its upper-left and the second point of contact 170 with the adjacent tube 120 to its lower-right. Then, in FIG. 7, the centermost tube 120 has the first point of contact 170 with the adjacent tube 120 directly to its left and the second point of contact 170 with the adjacent tube 120 directly to its right. In this way, the centermost tube 120 can encounter eight (8) different points of contact 170 through 180° of revolution along a portion of segment S, as represented by FIGS. 4-7. In contrast, as shown in FIGS. 4-7, with respect to any tube 120 other than the centermost tube 120 in tube bundle 140, such tube can encounter four (4) different points of contact 170 through 180° of revolution along a portion of segment S. Although FIGS. 4-10 depict twisted section 154 of a tube bundle 140 comprising seven individual tubes 120, it will be understood that the tube bundle 140 can comprise more tubes 120.

[0025] According to embodiments presented herein, and shown representatively in FIGS. 2-10, the intermittent twisted sections 154 of the tubes 120 can act as a support mechanism within the heat exchanger shell and further eliminate the need for baffles altogether. Further, the twisted nature of the twisted sections 154 permits for larger voids 180 between each tube 120 in a tube bundle 140, as best illustrated in the cross-sections in FIGS. 4-10. The efficiency of heat exchange between the tube-side fluid and the shell-side fluid, via the tube wall, can be further improved over known heat exchangers by a swirl flow created by the twisted segments of tubes 120 and the voids 180. Specifically, the swirl flow can be created by a swirling region defined by the individual tubes 120 of the tube bundle 140, and generally comprising the voids 180 along the twisted sections. The shell-side fluid can travel between the voids 180, and the varying space defined thereby, and generally along the length of the tubes 120 and tube bundle 140. In this way, the shell-side fluid can be acted upon by the tubes 120 depending on the orientations thereof relative to segment S, as best depicted in FIGS. 4-10, to create a swirl effect in the shell-side fluid, which can produce a swirl flow.

[0026] Further, because a twisted section 154 is generally adjacent to an at least one straight section 152, wherein the tubes 120 of the tube bundle 140 are generally arranged in a tighter arrangement with fewer and smaller voids between the tubes, the overall mechanical resonance of the tube 120 is not adversely affected by the spacing and voids 180 of the twisted section 154. The intermittent twisted segments 154 can support the tubes 120 and tube bundles 140 within the shell in a manner that provides a highly flexible support system with enhanced heat transfer on the tube- and shell-side flows, such that each tube 120 or tube bundle 140 is generally self-supporting, even without the use of baffles. Such support can be achieved, at least in part, by the twisted segments 154 which can produce tube-to-tube spaced-apart contact points 170 between adjacent tubes 120, while also defining the voids 180 discussed herein, with each individual tube 120 being secured in place by adjacent tubes 120, and facilitating securement of adjacent tubes 120. Such arrangement can reduce vibration and promote easier cleaning on the shell-side through the heat exchanger 100.

Claims

1. A heat-exchanging apparatus (100) comprising: a plurality of tubes (120) bundled adjacent one another, each of the plurality of tubes (120) having a tube body defining an interior passageway for carrying a first fluid, each of the plurality of tubes (120) having a plurality of segments along its length comprising a straight section (152) and a twisted section (154) in fluid communication with each other, wherein each of the plurality of tubes (120) has a central longitudinal axis along its length, the tube body along the twisted section (154) exhibiting rotation about the central longitudinal axis, the tube body along the straight section (152) exhibiting no rotation about the central longitudinal axis, an exterior surface of the tube body of a first tube of the plurality of tubes (120) coming into contact with an exterior surface of the tube body of a second tube of the plurality of tubes (120) along the twisted section (154), the exterior surfaces of the first and second tubes avoiding contact along the straight section (152), and the tube body of each of the plurality of tubes (120) is rotated at least 360° about its central longitudinal axis along the twisted section (154), characterized in that contact points (170) between the twisted section (154) of the first tube and adjacent twisted sections (154) of other adjacent tubes of the plurality of tubes (120) are present at rotation intervals on the order of 60° through said 360° rotation.

2. The heat-exchanging apparatus (100) of claim 1 further comprising an area around and between the plurality of tubes (120), the area forming a passageway for carrying a second fluid, so that the rotation of the tube body along the at least one twisted section (154) preferably causes the second fluid to exhibit a swirling action as it flows along the twisted section (154).

3. The heat-exchanging apparatus (100) of claim 1, wherein the plurality of segments of each tube comprises an alternating arrangement of straight (152) and twisted sections (154), wherein the twisted section (154) is located between first and second straight sections (152) and the straight section (152) is located between first and second twisted sections (154) and wherein the alternating arrangements of straight (152) and twisted sections (154) of each of the plurality of tubes (120) are preferably in line with one another, such that the twisted section (154) of the first tube is adjacent the twisted section (154) of the second tube and the straight section (152) of the first tube is adjacent to the straight section (152) of the second tube.

4. The heat exchanging apparatus (100) of claim 1, wherein rotation of the tube body of each of the plurality of tubes (120) in the twisted section (154) is synchronized such that rotation of the first tube corresponds with rotation of the second tube.

5. The heat exchanging apparatus (100) of claim 1, wherein upon entering the twisted section (154) each of the plurality of tubes (120) is in a first rotation orientation whereby the exterior surface of the tube body of the first tube contacts the exterior surface of the tube body of the second tube, the exterior surfaces of the tube bodies of the first and second tubes separating from one another as the tubes (120) rotate through the twisted section (154) away from the first rotation orientation and coming back into contact with one another when the tubes (120) are rotated at rotation intervals on the order of 180° from the first rotation orientation, wherein the exterior surface of the tube body of the first tube preferably comes into contact with an exterior surface of a tube body of a third tube of the plurality of tubes (120) when the tubes (120) are rotated at rotation intervals on the order of 60° and 240° from the first rotation orientation.

6. The heat exchanging apparatus (100) of claim 1, wherein the tube body of each of the plurality of tubes (120) has a substantially round cross-section profile occupying a given area along the straight section (152), the round cross-section profile being compressed through the twisted section (154), said compression causing a reduction of the given area and flattening of the round cross-section profile whereby opposing points of said round cross-sectional profile protrude outward, wherein the outward protrusion of opposing points of the tube body of the first tube in the twisted section (154) preferably permits contact with opposing points of the tube body of the second tube.

7. The heat exchanging apparatus (100) of claim 1: wherein the plurality of segments of each tube comprises a plurality of alternating straight sections (152) and a plurality of twisted sections (154) in fluid communication with each other, and wherein the heat exchanging apparatus further comprises a shell surrounding the plurality of tubes (120), the shell defining an area around and between the plurality of tubes (120), the area forming a passageway for carrying a second fluid.

8. The heat exchanging apparatus (100) of claim 7, wherein rotation of the tube body of each of the plurality of tubes (120) in the twisted sections (154) is synchronized where rotation of the first tube corresponds to rotation of the second tube.

9. The heat exchanging apparatus (100) of claim 7, wherein rotation of the tube body along the twisted sections (154) causes the second fluid to exhibit a swirling action as it flows along the twisted sections (154).

10. The heat exchanging apparatus (100) of claim 7, wherein the tube body of each of the plurality of tubes (120) is rotated at least 360° along the twisted sections (154), contact between adjacent tubes (120) being made at rotation intervals on the order of 60° through said rotation of said tube bodies.

11. The heat exchanging apparatus (100) of claim 7 wherein the tube body of each of the plurality of tubes (120) has a substantially round cross-section profile occupying a given area along the straight sections (152), the round cross-section profile being compressed through the twisted sections (154), said compression causing a reduction of the given area and flattening of the round cross-section profile whereby opposing points on said profile protrude outward, wherein outward protrusion of opposing points of the tube body of the first tube in the twisted sections (154) preferably permits contact with opposing points of the tube body of the second tube.

12. A method of carrying out heat exchange comprising: introducing a first fluid into a plurality of tubes (120) of a heat exchanging apparatus (100), the plurality of tubes (120) being bundled together, the each of the plurality of tubes (120) having a central longitudinal axis along its respective length and comprising a plurality of straight sections (152) and a plurality of twisted sections (154), the plurality of straight sections (152) and plurality of twisted sections (154) being in an alternating arrangement along a length of the tubes (120), the plurality of twisted sections (154) exhibiting rotation about the about the central longitudinal axis, the plurality of straight sections (152) exhibiting no rotation about the central longitudinal axis; directing a second fluid into the heat exchanging apparatus into an area adjacent the plurality of bundled tubes (120); and permitting the first fluid to flow within the plurality of tubes (120) through the alternating arrangement of straight sections (152) and twisted sections (154); supporting the plurality of tubes (120) within the heat exchanging apparatus (100) at contact points (170) along the plurality of twisted sections (154), the contact points (170) being locations along the plurality of twisted sections (154) where adjacent tubes (120) of the plurality of tubes (120) contact one another, wherein the tube body of each of the plurality of tubes (120) is rotated at least 360° about its central longitudinal axis along the twisted section (154), characterized in that contact points (170) between the twisted section (154) of the first tube and adjacent twisted sections (154) of other adjacent tubes of the plurality of tubes (120) are present at rotation intervals on the order of 60° through said 360° rotation.

13. The method of claim 12 further comprising causing the second fluid to exhibit a swirling action as it flows along the plurality of twisted sections (154).

14. A method of manufacturing a heat exchanging apparatus (100) comprising: bundling a plurality of tubes (120) adjacent one another, each of the plurality of tubes (120) having a tube body defining an interior passageway for carrying a first fluid and a central longitudinal axis along its length; forming a plurality of segments along a length of each of the plurality of tubes (120), the plurality of segments comprising an alternating sequence of straight tube sections (152) and twisted tube sections (154), the tube body along the twisted tube sections (154) exhibiting rotation about the central longitudinal axis, the tube body along the straight sections (152) exhibiting no rotation about the central longitudinal axis; aligning the straight tube sections (152) of each of the plurality of tubes (120) with one another such that the straight tube (152) sections along each of the plurality of tubes (120) are adjacent one another, exterior surfaces of the tube body of the plurality of tubes (120) avoiding contact with one another along the straight tube sections (152); aligning the twisted tube sections (154) of each of the plurality of tubes (120) with one another such that the twisted tube sections (154) along each of the plurality of tubes (120) are adjacent one another, the exterior surface of the tube body of each of the plurality of tubes (120) coming into contact with the exterior surface of the tube body of at least three other tubes of the plurality of tubes (120) along each twisted section (154), and forming an area around and between the plurality of tubes (120), the area forming a passageway for carrying a second fluid, wherein forming the plurality of segments along the length of each of the plurality of tubes (120) further comprises rotating each tube body of each twisted section at least 360° about its central longitudinal axis and providing contact points (170) of a first tube of the plurality of tubes (120) with other adjacent tubes of the plurality of tubes (120) in the twisted section (154) at rotation intervals on the order of 60°.