Heat exchange tube, heat exchanger tube core, heat exchanger and manufacturing method

Abstract

The application discloses a heat exchange tube, comprising: a first hollow tube comprising an open first end and a second end; and a second hollow tube comprising an open end and a closed end, the first hollow tube being built in the second hollow tube, a gap being formed between the outer wall of the first hollow tube and the inner wall of the second hollow tube, and the first end of the first hollow tube extending out of the open end of the second hollow tube, the second end being spaced apart from the inner wall of the closed end of the second hollow tube, and the part between the open end of the second hollow tube and the second end of the first hollow tube being spirally wound around a center. The application also discloses a heat exchanger tube core using the heat exchange tube, a heat exchanger and a manufacturing method thereof. By adopting the spiral wound and sleeved heat exchange tube, the heat exchange area can be increased, the heat exchange efficiency is improved, stress deformation and weld tearing caused by thermal expansion of the heat exchange tube in use of the heat exchanger tube core and the heat exchanger are avoided, and the possibility of dew point corrosion is reduced.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery in industries such as oil refining and chemical processing. Specifically, it relates to an improved heat exchange tube, heat exchanger core, heat exchanger, and manufacturing method for improving heat exchange efficiency. Background Technology

[0002] Counter-flow spiral wound tube heat exchangers have high heat exchange efficiency and are widely used in various fields. However, taking the practical application of heat exchange between acidic high-temperature flue gas and low-temperature medium as an example, the acidic high-temperature flue gas flows through the shell side, while the low-temperature medium flows through the tube side. Near the flue gas outlet, the high-temperature flue gas temperature decreases after heat exchange, while the corresponding tubes contain the low-temperature medium that has just flowed into the heat exchanger, resulting in a low tube wall temperature at the flue gas outlet. Because the acidic high-temperature flue gas contains acidic corrosive gas components, such as sulfur dioxide, when the temperature drops below its acid dew point corrosion temperature, it will corrode the metal heat exchange tubes, causing some heat exchange tubes to corrode and perforate, leading to leakage and affecting the heat exchanger's heat exchange effect and service life. However, if the exhaust gas temperature is increased to avoid dew point corrosion, it will result in the waste of high-temperature flue gas heat.

[0003] Therefore, heat exchanger tubes, heat exchanger cores, and heat exchangers that can solve the above problems and have high heat exchange efficiency are needed. Summary of the Invention

[0004] The purpose of this invention is to provide a heat exchange tube, a heat exchanger core, and a heat exchanger that at least partially solve the above-mentioned problems.

[0005] According to one aspect of the present invention, a heat exchange tube is provided, comprising: a first hollow tube and a second hollow tube, the first hollow tube including an open first end and a second end, the second hollow tube including an open end and a closed end, the first hollow tube being embedded in the second hollow tube, a gap being formed between the outer wall of the first hollow tube and the inner wall of the second hollow tube, and the first end of the first hollow tube extending beyond the open end of the second hollow tube, the second end of the first hollow tube being spaced apart from the inner wall of the closed end of the second hollow tube, wherein the portion between the open end of the second hollow tube and the second end of the first hollow tube of the heat exchange tube is wound in a spiral shape around a center.

[0006] The heat exchange tube of this invention is a spiral-sleeved heat exchange tube. Compared with the heat exchange tubes of the prior art wound-tube heat exchanger, the flow path of the fluid medium inside the heat exchange tube is the sum of the lengths of the first hollow tube and the second hollow tube. Therefore, the spiral-sleeved heat exchange tube of this invention increases the heat exchange area and can improve the heat exchange efficiency. Moreover, the outer wall temperature of the spiral-sleeved heat exchange tube of this invention is higher than that of the outer wall temperature of the heat exchange tube of the prior art wound-tube heat exchanger, reducing the possibility of dew point corrosion.

[0007] Preferably, the cross-sectional shapes of the first hollow tube and the second hollow tube are both biaxially symmetrical and are biaxially overlapping each other, with at least a portion of the ends of the cross-sections of the first hollow tube and the second hollow tube overlapping each other along one axis of symmetry.

[0008] The first and second hollow tubes are kept in contact with each other by their shape matching, which allows for a stable gap between them and relative axial movement. In actual use, when they expand and elongate due to heat, they will not restrain each other and cause stress deformation.

[0009] Preferably, the cross-sectional dimension of the first hollow tube is smaller than that of the second hollow tube.

[0010] Preferably, the first hollow tube includes a support member that extends from the outer wall of the first hollow tube and the extended end floats against the inner wall of the second hollow tube to maintain the gap between the first hollow tube and the second hollow tube.

[0011] According to the present invention, when the cross-sectional dimension of the first hollow tube is smaller than that of the second hollow tube (i.e., the first hollow tube is contained within the second hollow tube and their cross-sections do not intersect), a support member can be used to maintain a stable gap between the first and second hollow tubes. In practical use, since both the first and second hollow tubes are fixed individually, theoretically, a support member is not required to maintain a stable gap between them.

[0012] Preferably, the support is a bolt and nut assembly, wherein the bolt extends out of the first hollow tube through the first hollow tube and is held on the first hollow tube by the nut, or the support is a fin or rib fixed to the outer wall surface of the first hollow tube and extending therefrom.

[0013] Preferably, the cross-section of at least the second hollow tube includes a major axis and a minor axis.

[0014] According to another aspect of the present invention, a heat exchanger core is provided, comprising an upper tube sheet and a lower tube sheet, the upper tube sheet and the lower tube sheet respectively comprising through holes; a wound core extending axially, the upper end of which is fixed to the center of the lower tube sheet; and a heat exchanger tube layer, wherein a heat exchanger tube layer comprises at least one heat exchanger tube, the heat exchanger tube being the aforementioned heat exchanger tube, the heat exchanger tubes in each layer being wound with the wound core as the center with the same helical radius and helical angle, the first end of the first hollow tube of the heat exchanger tube passing through the through hole in the upper tube sheet and being sealed thereto, the open end of the second hollow tube of the heat exchanger tube passing through the through hole in the lower tube sheet and being sealed thereto, and the lower end of the heat exchanger tube being a free end.

[0015] The heat exchanger core according to the present invention uses the heat exchange tube as described above, and the lower end of the heat exchange tube is kept as a free end. Therefore, it can increase the heat exchange area and improve the heat exchange efficiency. At the same time, it can avoid stress deformation and weld tearing caused by thermal expansion of the heat exchange tube during the use of the heat exchanger core, and also reduce the possibility of dew point corrosion.

[0016] Preferably, the heat exchange tubes in adjacent heat exchange tube layers are wound in opposite directions, and the lengths of the heat exchange tubes are basically the same.

[0017] Setting the winding direction of heat exchange tubes in adjacent heat exchange tube layers in opposite directions will increase turbulence between the heat exchange tube layers and improve heat exchange efficiency. Setting the length of the heat exchange tubes in the wound tube heat exchanger to be basically the same can ensure that the pressure drop of the heat exchange tubes is consistent and guarantee heat exchange uniformity.

[0018] Preferably, the open end of the second hollow tube of the heat exchange tube extends and is open between the upper tube sheet and the lower tube sheet, and the portion of the first hollow tube and the second hollow tube between the upper tube sheet and the lower tube sheet is a straight tube section.

[0019] The open end of the second hollow tube is not limited to being located on the lower tube sheet; it can also extend and open between the upper and lower tube sheets. The portions of the first and second hollow tubes between the upper and lower tube sheets are straight sections to facilitate their insertion into corresponding through holes in the upper and lower tube sheets.

[0020] Preferably, the heat exchange tube includes a straight tube section and a transition tube section between the lower tube sheet and the portion where the heat exchange tube is wound in a spiral shape.

[0021] The installation of straight pipe sections and transition pipe sections can prevent excessive deformation of the heat exchange tubes during manufacturing and processing.

[0022] Preferably, the heat exchanger tube core further includes a retaining plate fixed to the shell. The retaining plate includes a heat exchanger tube through-hole with the same cross-sectional shape as the second hollow tube. The heat exchanger tube includes a transition section and a straight section sequentially between the spirally wound portion and the free end. The straight section passes through the heat exchanger tube through-hole on the retaining plate and is clearance-fitted to it. The fixed connection between the retaining plate and the shell can be a non-removable connection such as welding, or a detachable connection such as bolts and nuts. The detachable connection of the retaining plate facilitates the maintenance of the heat exchanger tube core, for example, facilitating dust removal.

[0023] Preferably, the heat exchanger core also includes a retaining plate, which is fixedly connected to the lower end of the wound core and the lower end of the heat exchange tube respectively. The retaining plate can move with the lower end of the wound core and the lower end of the heat exchange tube when they are heated and expand freely.

[0024] The retaining plate prevents the heat exchange tubes and wound core from vibrating due to the scouring of the fluid medium during use, ensuring the normal operation of the heat exchanger. In addition to preventing vibration of the heat exchange tubes and wound core, the retaining plate also keeps the lower ends of the heat exchange tubes and wound core as free ends, thus avoiding stress and deformation caused by thermal expansion during use.

[0025] Preferably, the cross-section of at least the second hollow tube of the heat exchange tube includes a major axis and a minor axis, wherein the major axis is configured to be parallel to the central axis of the wound core.

[0026] Setting the major axis of the cross-section of the outer tube of the heat exchanger to be parallel to the flow direction of the second fluid medium outside the tube, that is, parallel to the axial direction of the heat exchanger, can reduce the flow resistance of the second fluid medium and the stagnation area behind the tube, thereby further improving the heat exchange efficiency.

[0027] According to another aspect of the present invention, a heat exchanger is provided, comprising: a shell extending longitudinally and including a first fluid medium inlet and a first fluid medium outlet, a second fluid medium inlet and a second fluid medium outlet; and a heat exchanger core disposed within the shell according to the foregoing description, the heat exchanger core being sealed to the shell via an upper tube sheet and a lower tube sheet, wherein the first fluid medium inlet is fluidly sealed to a first end of a first hollow tube, the first fluid medium outlet is fluidly sealed to an open end of a second hollow tube, the first fluid medium inlet, the first end of the first hollow tube, the inner cavity of the first hollow tube, the second end of the first hollow tube, the gap between the first and second hollow tubes, the open end of the second hollow tube and the first fluid medium outlet form a first fluid medium channel, the second fluid medium inlet and the second fluid medium outlet forming a second fluid medium channel sealed and isolated from the first fluid medium channel with the shell, and a portion of the heat exchanger tube located below the lower tube sheet extending into the second fluid medium channel.

[0028] The heat exchanger according to the present invention, by using the heat exchange tubes and heat exchanger cores described above, can increase the heat exchange area and improve the heat exchange efficiency. At the same time, it can avoid stress deformation and weld tearing caused by thermal expansion of the heat exchange tubes during the use of the heat exchanger cores and the heat exchanger, and can also reduce the possibility of dew point corrosion.

[0029] Preferably, the first fluid medium inlet is located on the shell above the upper tube sheet, the first fluid medium outlet is located on the shell between the upper and lower tube sheets, the second fluid medium outlet is located on the shell corresponding to the free end of the heat exchange tube, and the second fluid medium inlet is located directly below the lower tube sheet.

[0030] Preferably, the heat exchanger includes at least two first fluid medium outlets, which are evenly spaced on the shell between the upper tube sheet and the lower tube sheet.

[0031] Setting multiple first fluid medium outlets at even intervals enables the first fluid medium to flow out of the heat exchanger uniformly and quickly.

[0032] According to another aspect of the present invention, a method for manufacturing a heat exchanger core or a heat exchanger is provided, the heat exchanger core or heat exchanger comprising at least one heat exchanger tube layer, each heat exchanger tube layer comprising at least one heat exchanger tube, the heat exchanger tube comprising: a first hollow tube and a second hollow tube, the first hollow tube comprising an open first end and a second end, the second hollow tube comprising an open end and a closed end, the first hollow tube being embedded within the second hollow tube, a gap being formed between the outer wall of the first hollow tube and the inner wall of the second hollow tube, and the first end of the first hollow tube extending beyond the open end of the second hollow tube, the second end of the first hollow tube being spaced apart from the inner wall of the closed end of the second hollow tube, the manufacturing method comprising:

[0033] a) Pass the open end of the second hollow tube of the heat exchanger tube in the innermost heat exchanger tube layer through the corresponding through hole on the heat exchanger core or the lower tube sheet of the heat exchanger and seal it thereto; insert the second end of the first hollow tube of the heat exchanger tube into the second hollow tube and into the appropriate position to form the required sleeve.

[0034] b) The portion of the sleeve formed in step a) between the open end of the second hollow tube and the second end of the first hollow tube is wound around the core in a spiral shape.

[0035] c) Form the required sleeve for the heat exchange tubes of the next layer according to step a);

[0036] d)) The open end of the second hollow tube of the sleeve in step c) and the middle part of the second end of the first hollow tube are wound around the core and the heat exchange tube that has been wound into a spiral shape.

[0037] e) Repeat steps c)-d) until the heat exchange tubes in the last heat exchange tube layer are arranged;

[0038] f) Pass the first end of the first hollow tube of all heat exchange tubes through the corresponding through hole in the heat exchanger core or the upper tube sheet of the heat exchanger and seal it thereto.

[0039] In summary, the heat exchange tube, heat exchanger core, and heat exchanger of the present invention, by employing a spiral-wound, sleeve-type heat exchange tube with one end of the heat exchange tube remaining free, can increase the heat exchange area and improve the heat exchange efficiency. At the same time, it avoids stress deformation and weld tearing caused by thermal expansion of the heat exchange tube during the use of the heat exchanger core and heat exchanger, and can also reduce the possibility of dew point corrosion. Attached Figure Description

[0040] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0041] Figure 1 This is a perspective view of a heat exchanger according to a first embodiment of the present invention;

[0042] Figure 2 yes Figure 1 Front sectional view of the heat exchanger shown;

[0043] Figure 3 yes Figure 1 Left view of the heat exchanger shown;

[0044] Figure 4 It is along Figure 2 Top sectional view of the heat exchanger taken at section AA;

[0045] Figure 5 This is a front sectional view of a heat exchanger according to a second embodiment of the present invention;

[0046] Figure 6 This is a perspective view of a sleeve-type heat exchange tube for forming a heat exchange tube according to a first embodiment of the heat exchange tube of the heat exchanger according to the present invention;

[0047] Figure 7 yes Figure 6 A cross-sectional view of the heat exchange tube shown;

[0048] Figure 8 yes Figure 6 A top view of the heat exchange tubes shown;

[0049] Figure 9 , Figure 10 and Figure 11 These are top views of the shell-and-tube heat exchange tubes of the second to fourth embodiments of the heat exchange tubes used to form the heat exchange tubes of the heat exchanger according to the present invention.

[0050] Figure 12 This is a perspective view of a shell-and-tube heat exchange tube according to a fifth embodiment of a heat exchange tube for forming a heat exchanger according to the present invention;

[0051] Figure 13 yes Figure 12 A cross-sectional view of the heat exchanger tubes;

[0052] Figure 14 yes Figure 12 Top view of the heat exchanger tubes;

[0053] Figure 15 This is a perspective view of a sleeve-type heat exchange tube according to a sixth embodiment of a heat exchange tube for forming a heat exchanger according to the present invention.

[0054] Figure 16yes Figure 15 A cross-sectional view of the heat exchanger tubes;

[0055] Figure 17 yes Figure 15 Top view of the heat exchanger tubes;

[0056] Figure 18 , Figure 19 and Figure 20 These are top views of the seventh to ninth embodiments of the shell-and-tube heat exchange tubes used to form the heat exchange tubes of the heat exchanger according to the present invention.

[0057] Figure 21 This is a perspective view of the heat exchanger core used in a heat exchanger according to a first embodiment of the present invention;

[0058] Figure 22 yes Figure 21 A cross-sectional view of the heat exchanger tube core in the diagram;

[0059] Figure 23 This is a front sectional view of the heat exchanger core used in a heat exchanger according to a second embodiment of the present invention. Detailed Implementation

[0060] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0061] In this invention, the terms "upper," "lower," "inner," "outer," "center," "longitudinal," and "axial" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or to be constructed and operated in a specific orientation.

[0062] Figure 1 This is a perspective view of a heat exchanger according to a first embodiment of the present invention. The heat exchanger is generally indicated by reference numeral 100. The heat exchanger 100 includes a shell 101 and a heat exchanger core 102.

[0063] The housing 101 includes a housing body 110, a first fluid medium inlet 111 and a first fluid medium outlet 112 disposed on the housing body 110, and a second fluid medium inlet 127 and a second fluid medium outlet 126. The housing body 101 is transparently displayed to clearly show the interior of the heat exchanger 100.

[0064] The heat exchanger core 102 is disposed inside the shell body 110 of the shell 101, and includes an upper tube sheet 122, a lower tube sheet 123, a wound core 124 fixedly connected to the center of the lower tube sheet 123, and heat exchange tubes 121 wound around the wound core 124. The heat exchange tube 121, as a whole, includes two ends, namely... Figure 1 The top and bottom of each heat exchange tube 121 shown in the image.

[0065] Figure 2 yes Figure 1 The figure shows a front sectional view of the heat exchanger 100, with a partially enlarged sectional view of the heat exchange tube 121 circled in the figure. From the partially enlarged sectional view of the heat exchange tube 121, it can be seen that the heat exchange tube 121 includes a first hollow tube 1211 and a second hollow tube 1212, with the first hollow tube 1211 embedded within the second hollow tube 1212. The upper end of the first hollow tube 1211 passes through a through hole in the upper tube sheet 122 and is sealed thereto. The upper end of the second hollow tube 1212 of the heat exchange tube 121 passes through a through hole in the lower tube sheet 123 and is sealed thereto. Thus, the shape of the through hole on the upper tube sheet 122 is the same as the cross-sectional shape of the first hollow tube 1211, and the shape of the through hole on the lower tube sheet 123 is the same as the cross-sectional shape of the second hollow tube 1212. To facilitate the passage of the first hollow tube 1211 through the lower tube sheet 123 and the upper tube sheet 122 respectively, the portion of the first hollow tube 1211 between the upper tube sheet 122 and the lower tube sheet 123 is a straight section.

[0066] Also refer to Figure 1 and Figure 2 As shown in the figure, the upper end of the first hollow tube 1211 extends beyond the upper end of the second hollow tube 1212. A gap is formed between the outer wall of the first hollow tube 1211 and the inner wall of the second hollow tube 1212. The middle portion of the heat exchange tube 121 is wound in a spiral shape around the core 124. Between the lower tube sheet 122 and the spiral portion of the heat exchange tube 121, there are sequentially straight tube sections and transition tube sections to prevent excessive deformation of the heat exchange tube 121 when it is wound in a spiral shape.

[0067] The heat exchanger core 102 is sealed to the shell body 110 of the shell 101 via the upper tube sheet 122 and the lower tube sheet 123. Thus, the first fluid medium inlet 111 is fluidly sealed to the upper end of the first hollow tube 1211, and the first fluid medium outlet 112 is fluidly sealed to the upper end of the second hollow tube. The first fluid medium inlet 111, the upper end of the first hollow tube 1211, the inner cavity of the first hollow tube 1211, the lower end of the first hollow tube 1211, the gap between the first hollow tube 1211 and the second hollow tube 1212, the upper end of the second hollow tube 1212, and the first fluid medium outlet 112 form a first fluid medium channel. The second fluid medium inlet 127 and the second fluid medium outlet 126 form a second fluid medium channel with the shell body 110 that is sealed and isolated from the first fluid medium channel. The portion of the heat exchange tube 121 located below the lower tube sheet 123 extends into the second fluid medium channel.

[0068] Therefore, in this embodiment, the total length of the heat exchange tube through which the first fluid medium flows in the heat exchange tube 121 is the sum of the length of the first hollow tube 1211 and the length of the second hollow tube 1212. Compared with the prior art spiral tube heat exchanger that uses non-coiled heat exchange tubes, the actual total length of the heat exchange tube 121 of the heat exchanger 100 of the present invention is increased by about 100% while the external length of the heat exchange tube is the same. Therefore, the heat exchange area is increased and the heat exchange efficiency is improved.

[0069] Meanwhile, since the outer wall temperature of the heat exchange tube 121 is the same as the outer wall temperature of the second hollow tube 1212, it depends on the temperature of the first fluid medium between the outer wall of the first hollow tube 1211 and the inner wall of the second hollow tube 1212. The heat exchange tube 121 is usually filled with a first fluid medium at a lower temperature, while the outside of the heat exchange tube 121 is usually filled with a second fluid medium at a higher temperature. After heat exchange, the temperature of the first fluid medium between the outer wall of the first hollow tube 1211 and the inner wall of the second hollow tube 1212 is usually higher than the temperature of the first fluid medium inside the first hollow tube 1211. Therefore, compared with the non-coiled heat exchange tubes of the prior art, the temperature of the outer wall of the heat exchange tube 121 of the present invention is higher than the outer wall temperature of the non-coiled heat exchange tubes of the prior art, reducing the possibility of dew point corrosion.

[0070] Taking acidic high-temperature flue gas as the second fluid medium and room temperature air as the first fluid medium as the example, in the existing spiral tube heat exchanger using non-coiled heat exchange tubes, the first fluid medium usually enters from the top of the shell and exits from the bottom of the shell, and only performs one countercurrent heat exchange with the second fluid medium. The temperature of the outer wall of the tube near the inlet of the heat exchange tube is low, and the temperature of the second fluid medium outside the tube near the inlet of the heat exchange tube is also low. If the temperature of the second fluid medium on the outer wall of the tube near the inlet of the heat exchange tube drops below the dew point temperature, the heat exchange tube may experience dew point corrosion at that location. According to the heat exchanger 100 of the present invention, from the flow process of the first fluid medium in the first fluid medium channel, it can be seen that the flow direction of the first fluid medium in the inner cavity of the first hollow tube 1211 is from top to bottom. When the first fluid medium flows out from the lower end of the first hollow tube 1211 into the gap between the outer wall of the first hollow tube 1211 and the inner wall of the second hollow tube 1212, the flow direction of the first fluid medium changes to from bottom to top. Meanwhile, the flow direction of the second fluid medium outside the heat exchange tube 121 is from the second fluid medium inlet 127 towards the second fluid medium outlet 126, that is, from top to bottom. Therefore, the first... The first fluid medium in the inner cavity of a hollow tube 1211 and the first fluid medium in the gap between the outer wall of the first hollow tube 1211 and the inner wall of the second hollow tube 1212 undergo a first countercurrent heat exchange through the tube wall of the first hollow tube 1211. The first fluid medium in the gap between the outer wall of the first hollow tube 1211 and the inner wall of the second hollow tube 1212 undergoes a second countercurrent heat exchange with the second fluid medium outside the second hollow tube 1212 through the outer tube wall of the heat exchange tube 121, i.e., the tube wall of the second hollow tube 1212. Therefore, compared with the traditional wound tube heat exchanger, the heat exchange efficiency is greatly improved.

[0071] Furthermore, in conventional wound tube heat exchangers, the second fluid medium at the outlet of the second fluid medium is low-temperature flue gas after heat exchange, and the first fluid medium at this location is low-temperature air that has not undergone sufficient heat exchange. Therefore, the outer wall temperature of the heat exchange tube at this location is also low. However, in the heat exchanger 100 according to the present invention, after heat exchange, at the outlet of the second fluid medium 126, the second fluid medium outside the second hollow tube 1212 is low-temperature flue gas after heat exchange, while the first fluid medium inside the second hollow tube 1212 is high-temperature air after at least one countercurrent heat exchange. Therefore, the outer wall temperature of the heat exchange tube 121 at the outlet of the second fluid medium 126 is higher, which reduces the possibility of dew point corrosion on the outer wall of the heat exchange tube 121 at this location compared to conventional wound tube heat exchangers.

[0072] In this embodiment, the heat exchanger core 102 also includes a retaining plate 125, which is fixed to the housing body 110. The retaining plate 125 can prevent the heat exchange tube 121 or the wound core 124 from vibrating due to the scouring of the fluid medium, thus avoiding any impact on heat exchange. The retaining plate 125 is provided with through holes (not shown in the figure) corresponding to the lower ends of the heat exchange tube 121 and the wound core 124. The lower ends of the heat exchange tube 121 and the wound core 124 are clearance-fitted with the through holes of the retaining plate 125. In this way, when the heat exchange tube 121 and the wound core 124 are heated and expanded in the working state of the heat exchanger 100, the lower ends of the heat exchange tube 121 and the wound core 124 can freely extend along the central axis of the housing, avoiding expansion stress and deformation between the heat exchange tube 121, the wound core 124, the lower tube sheet 123, and the retaining plate 124. Moreover, the first hollow tube 1211 is only sealed to the upper tube sheet 122 at its upper end, and the second hollow tube 1212 is only sealed to the lower tube sheet 123 at its upper end. The lower ends of the first hollow tube 1211 and the second hollow tube 1212 are both free ends, and the sealing connection is usually welded. Therefore, this structure can protect the welds between the upper end of the first hollow tube 1211 and the upper tube sheet 122, and between the upper end of the second hollow tube 1212 and the lower tube sheet 123 from being torn, and has good sealing performance.

[0073] In this embodiment, the fixed connection between the retaining plate 125 and the housing body 110 can be a non-removable connection such as a welded connection, or a detachable connection such as a bolt and nut connection (not shown in the figure). When a detachable connection is used, it is convenient for the maintenance of the heat exchange tube, such as for the removal of ash accumulated on the heat exchange tube. Figure 3 yes Figure 1 The left view of the heat exchanger 100 shown. Figure 4 It is along Figure 2 A top sectional view of the heat exchanger taken at section AA. Also refer to... Figure 1-4 As shown in the figure, the first fluid medium inlet 111 is located on the housing body 110 above the upper tube sheet 122, and the first fluid medium outlet 112 is located on the housing body 110 between the upper tube sheet 122 and the lower tube sheet 123. Figure 3 As can be seen, the first fluid medium outlet 112 corresponds to the portion of the first hollow tube 1211 extending beyond the upper end of the second hollow tube 1212; the second fluid medium outlet 126 corresponds to the free end of the heat exchange tube 121 and is located on the shell body 110; the second fluid medium inlet 127 is located immediately below the lower tube sheet 123. (Refer to...) Figure 2 and Figure 4 As clearly shown in the figure, in this embodiment, two first fluid medium outlets 112 are provided to allow the first fluid medium to flow out quickly and uniformly from the shell body 110 of the heat exchanger 100.

[0074] Continue to refer to Figure 2 and Figure 4 For clarity, this embodiment only schematically shows three heat exchange tubes 121 arranged in each of the three heat exchange tube layers. In actual use, the number of heat exchange tubes 121 and heat exchange tube layers is not limited by this embodiment. Each heat exchange tube layer includes at least one heat exchange tube, and the heat exchange tubes in the same heat exchange tube layer are wound with the same helical radius and helical angle. The figure also shows that the winding directions of the heat exchange tubes 121 in adjacent heat exchange tube layers are opposite. The opposite winding directions of the heat exchange tubes will increase the turbulence between heat exchange tube layers and improve the heat exchange efficiency. By setting different helical angles for the heat exchange tubes 121 in each heat exchange tube layer, the length of the heat exchange tubes 121 in all heat exchange tube layers can be made to be basically the same, thereby ensuring that the first fluid medium travels the same distance and has the same pressure drop within the heat exchange tubes 121.

[0075] In this embodiment, the retaining plate 125 may not be fixed to the housing body 110, but may be clearance-fitted with the housing body 110 and fixedly connected to the lower end of the wound core 124 and the free end of the heat exchange tube 121. When the heat exchange tube 121 expands axially due to heat, the retaining plate 125 moves freely along the axial direction as the heat exchange tube 121 and the lower end of the wound core 124 expand axially. In this embodiment, there are two first fluid medium outlets 112, but the invention is not limited to this; multiple first fluid medium outlets can be evenly spaced. In this embodiment, the second fluid medium inlet 127 is located directly below the lower tube sheet 123, and the second fluid medium outlet 126 is located below the housing, forming a secondary countercurrent heat exchange with the heat exchange tube 121. However, the invention is not limited to this; the positions of the second fluid medium inlet 127 and the second fluid medium outlet 126 can be interchanged, which is within the scope of protection of the invention. In this embodiment, the upper end of the first hollow tube 1211 terminates in the upper tube sheet 122, and the upper end of the second hollow tube 1212 terminates in the lower tube sheet 123. However, the present invention is not limited to this. The upper end of the first hollow tube 1211 may extend above the upper tube sheet 122, and the upper end of the second hollow tube 1212 may extend and open between the upper tube sheet 122 and the lower tube sheet 123.

[0076] In the sleeve-type spiral wound heat exchanger 100 according to this embodiment of the present invention, since the upper end of the first hollow tube 1211 and the upper end of the second hollow tube 1212 need to be sealed and connected to the upper tube sheet 122 and the lower tube sheet 123 respectively, in the actual manufacturing process, the innermost heat exchange tube 121 is processed first. The upper end of the second hollow tube 1212 of the innermost heat exchange tube 121 is passed through the corresponding through hole on the lower tube sheet 123 and welded and sealed thereto. Then, the lower end of the first hollow tube 1211 of the heat exchange tube 121 is inserted into the second hollow tube 1212 to a suitable position to form the required sleeve. Then, the portion of the sleeve between the upper end of the second hollow tube 1212 and the lower end of the first hollow tube 1211 is wound into a spiral shape around the winding core 124; then, the sleeve is formed according to the same steps as the innermost heat exchange tube 121, and the portion of the sleeve between the open end of the second hollow tube and the second end of the first hollow tube is wound into a spiral shape around the winding core; then, the above steps are repeated until the heat exchange tubes 121 in the last heat exchange tube layer are arranged; finally, the upper ends of the first hollow tubes 1211 of all heat exchange tubes 121 are passed through the corresponding through holes of the upper tube sheet 122 and welded to seal them.

[0077] Considering the ease of processing the spiral wound heat exchange tubes used in the heat exchanger according to the present invention, a spiral wound heat exchange tube with a circular cross-section can be used in the heat exchange tube layer near the winding core, or an ordinary spiral wound heat exchange tube can be used to reduce processing resistance.

[0078] Figure 5 This is a front sectional view of a heat exchanger according to a second embodiment of the present invention. The heat exchanger is generally indicated by reference numeral 200.

[0079] The difference between this second embodiment and the first embodiment is that the second embodiment does not include a retaining plate, and the lower ends of the heat exchange tube 221 and the wound core 224 remain free ends. In this embodiment, the lower end of the housing body 210 can be made detachable to facilitate the maintenance of the heat exchange tube, such as removing accumulated dust.

[0080] Figure 5 Although the heat exchange tube 221 is shown to include a transition section and a straight section between the middle spiral part and the free end, the straight section may also be omitted since the retaining plate is not included.

[0081] The following reference Figure 6-19 An embodiment of a shell-and-tube heat exchanger tube forming the heat exchanger tube used in the heat exchanger of the present invention is described. For clarity, Figure 6-19 The sleeve-type heat exchange tube shown is a straight heat exchange tube, which is formed by winding it around a winding core to form the heat exchange tube used in the heat exchanger of the present invention.

[0082] Figure 6 This is a perspective view of a shell-and-tube heat exchanger tube according to a first embodiment of a heat exchanger tube for forming a heat exchanger according to the present invention. Figure 7 yes Figure 6 The diagram shows a cross-sectional view of the heat exchange tube. The heat exchange tube is generally designated 321. Heat exchange tube 321 includes a first hollow tube 3211 and a second hollow tube 3212. The first hollow tube 3211 includes an open first end and a second end. The second hollow tube 3212 includes an open end and a closed end. The first hollow tube 3211 is housed within the second hollow tube 3212. A gap is formed between the outer wall of the first hollow tube 3211 and the inner wall of the second hollow tube 3212. The first end of the first hollow tube 3211 extends beyond the open end of the second hollow tube 3212. The second end of the first hollow tube 3211 is spaced apart from the inner wall of the closed end of the second hollow tube 3212.

[0083] Figure 8 yes Figure 6 The top view of the heat exchange tube 321 shown. Figure 8 As shown, the first hollow tube 3211 has a circular cross-section, and the second hollow tube 3212 has an elliptical cross-section. The outer diameter of the first hollow tube 3211 is equal to the minor axis inner diameter of the elliptical cross-section of the second hollow tube 3212. That is, the outer end of the cross-section of the first hollow tube 3211 along the minor axis direction overlaps with the inner end of the cross-section of the second hollow tube 3212 along the minor axis direction. Thus, through form fit, the first hollow tube 3211 is held in the second hollow tube 3212, and a stable gap is formed between the outer wall of the first hollow tube 3211 and the inner wall of the second hollow tube 3212. However, this fit also allows the first hollow tube 3211 and the second hollow tube 3212 to slide axially relative to each other. In actual use, when thermally expanded, they will not restrict each other and generate expansion stress.

[0084] Figure 9-11 This is a top view of a shell-and-tube heat exchanger tube used to form a heat exchanger tube according to the second to fourth embodiments of the present invention. Figure 9-11 The illustrated embodiment is Figure 6-8The figure shows a variation of the embodiment. The heat exchange tubes 421, 421', 421" shown in the figure each include a first hollow tube 4211, 4211', 4211" and a second hollow tube 4212, 4212', 4212" respectively. The cross-sections of the first hollow tubes 4211, 4211', 4211" and the second hollow tubes 4212, 4212', 4212" are both biaxially symmetric, meaning they have two axes of symmetry. The ends of the outer cross-sections of the first hollow tubes 4211, 4211', 4211" along the long axis are connected to the second hollow tube 4212. The ends of the inner cross sections of 4212' and 4212" along the long axis coincide, thereby, through a form fit, holding the first hollow tubes 4211, 4211', and 4211" within the second hollow tubes 4212, 4212', and 4212" and forming a stable gap between the outer walls of the first hollow tubes 4211, 4211', and 4211" and the inner walls of the second hollow tubes 4212, 4212', and 4212". The form fit of the cross sections is not limited to only one end of the cross section along one of its two axes of symmetry, such as... Figure 11 The heat exchange tube 421' shown has a first hollow tube 4211' with a dumbbell-shaped cross-section that bulges in the middle, and a second hollow tube 4212' with a rectangular cross-section. The outer cross-section of the first hollow tube 4211' not only partially overlaps with the end of the inner cross-section of the second hollow tube 4212' along the long axis, but they also partially overlap along their long sides. Similarly, Figure 9-11 The shape fit shown also allows the first hollow tubes 4211, 4211', 4211” and the second hollow tubes 4212, 4212', 4212” to slide axially relative to each other. In actual use, when thermally expanded, they will not restrict each other and generate expansion stress and deformation.

[0085] The other structures of heat exchange tubes 421, 421' and 421" are all the same as those of heat exchange tubes 421, 421' and 421". Figure 6-8 The heat exchange tube 321 shown is the same as that shown, and will not be described in detail here.

[0086] Figure 12 This is a perspective view of a shell-and-tube heat exchanger tube according to a fifth embodiment of a heat exchanger tube for forming a heat exchanger according to the present invention. Figure 13 yes Figure 12A cross-sectional view of the heat exchange tube. The heat exchange tube is generally designated as 521. The heat exchange tube 521 includes a first hollow tube 5211 and a second hollow tube 5212. The first hollow tube 5211 includes an open first end and a second end. The second hollow tube 5212 includes an open end and a closed end. The first hollow tube 5211 is built into the second hollow tube 5212. A gap is formed between the outer wall of the first hollow tube 5211 and the inner wall of the second hollow tube 5212. The first end of the first hollow tube 5211 extends beyond the open end of the second hollow tube 5212. The second end of the first hollow tube 5211 is spaced apart from the inner wall of the closed end of the second hollow tube 5212.

[0087] Figure 14 yes Figure 12 The top view of the heat exchange tube 521 shown. Figure 14 As shown, both the first hollow tube 5211 and the second hollow tube 5212 have circular cross-sections. The outer diameter of the first hollow tube 5211 is smaller than the inner diameter of the second hollow tube 5212. Spiral fins 5213, serving as supports, are formed on the outer wall of the first hollow tube 5211. These fins 5213 create a stable gap between the outer wall of the first hollow tube 5211 and the inner wall of the second hollow tube 5212. Furthermore, the spiral fins 5213 float against the inner wall of the second hollow tube 5212, allowing the first and second hollow tubes 5211 to slide relative to each other. During actual use, when thermally expanded, they do not restrict each other and generate expansion stress. In this embodiment, the first fluid medium flows along the spiral direction of the fins in the gap between the outer wall of the first hollow tube 5211 and the inner wall of the second hollow tube 5212. The spiral fins 5213 enhance turbulence, further improving the heat exchange effect.

[0088] Figure 15 This is a perspective view of a shell-and-tube heat exchange tube according to a sixth embodiment of a heat exchange tube for forming a heat exchanger according to the present invention. Figure 16 yes Figure 15 A cross-sectional view of the heat exchange tube. The heat exchange tube is generally designated 621. The heat exchange tube 621 includes a first hollow tube 6211 and a second hollow tube 6212. The first hollow tube 6211 includes an open first end and a second end. The second hollow tube 6212 includes an open end and a closed end. The first hollow tube 6211 is built into the second hollow tube 6212. A gap is formed between the outer wall of the first hollow tube 6211 and the inner wall of the second hollow tube 6212. The first end of the first hollow tube 6211 extends beyond the open end of the second hollow tube 6212. The second end of the first hollow tube 6211 is spaced apart from the inner wall of the closed end of the second hollow tube 6212.

[0089] Figure 17 yes Figure 15The top view of the heat exchange tube 621 shown. Figure 17 As shown, the first hollow tube 6211 has a rectangular cross-section, and the second hollow tube 6212 has an elliptical cross-section. The major and minor axes of the first hollow tube 6211 are both smaller than those of the second hollow tube 6212. A rib 6213, serving as a support, is formed on the outer wall of the first hollow tube 6211. This rib 6213 is discontinuous in the axial direction of the heat exchange tube, i.e., it is in a discrete segmented form. This allows the rib 6213 to create a stable gap between the outer wall of the first hollow tube 6211 and the inner wall of the second hollow tube 6212, while also preventing significant resistance to the spiral winding of the heat exchange tube 621. Furthermore, the rib 6213 floats against the inner wall of the second hollow tube 6212, allowing the first and second hollow tubes 6211 and 6212 to slide relative to each other axially. In actual use, during thermal expansion, they do not restrict each other and generate expansion stress.

[0090] In theory, Figure 12-14 Spiral fins 5213 and Figure 15-17 The stiffening rib 6213 can also be formed on the inner wall of the second hollow tube 5212 or the second hollow tube 6212.

[0091] Figure 18-20 This is a top view of a shell-and-tube heat exchanger tube according to the seventh to ninth embodiments of a heat exchanger tube for forming a heat exchanger according to the present invention. Figure 18-20 The illustrated embodiment is Figure 12-17The illustrated embodiment is a variation. The heat exchange tubes 721, 721', 721" shown in the figure include first hollow tubes 7211, 7211', 7211" and second hollow tubes 7212, 7212', 7212" . The cross-sections of the first hollow tubes 7211, 7211', 7211" and the second hollow tubes 7212, 7212', 7212" all have a major axis and a minor axis, with the two axes of symmetry overlapping. The major and minor axis dimensions of the cross-sections of the first hollow tubes 7211, 7211', 7211" are both smaller than those of the second hollow tubes 7212, 7212', 7212" . Between the first hollow tubes 7211, 7211', 7211" and the second hollow tubes 7212, 7212', 7212" The support members 7213, 7213', 7213" are bolt and nut assemblies. The bolts extend from the first hollow tubes 7211, 7211', 7211" through the first hollow tubes 7211, 7211', 7211" and are held in place by nuts. Moreover, the bolt heads of the bolt and nut assemblies 7213, 7213', 7213" float against the inner wall of the second hollow tubes 7212, 7212', 7212" allowing the first hollow tubes 7211, 7211', 7211" and the second hollow tubes 7212, 7212', 7212" to slide relative to each other. In actual use, when thermally expanded, they will not restrict each other and generate expansion stress.

[0092] Therefore, the support member for the heat exchange tube of the heat exchanger according to the present invention should not only maintain the gap and the space for fluid medium flow, but also be able to spirally distribute as the heat exchange tube is wound, so as not to generate excessive resistance to the winding of the heat exchange tube.

[0093] Return to reference Figure 1-5 Since in heat exchangers 100 or 200, the upper ends of the first hollow tubes 1211 and 2211 of heat exchange tubes 121 or 221 are sealed to the upper tube sheet 122 or 222, and the upper ends of the second hollow tubes 1212 and 2212 are sealed to the lower tube sheet 123 or 223, and the upper tube sheet 122 or 222 and the lower tube sheet 123 or 223 are respectively fixedly connected to the inner wall of the shell body 110 or 210, theoretically the relative positions of the first hollow tubes 1211 and 2211 and the second hollow tubes 1212 and 2212 remain fixed. Figure 12-20 The support structure in the heat exchanger tube embodiment shown may also be omitted.

[0094] Figure 21 This is a perspective view of the separate heat exchanger core 102 of the heat exchanger 100 according to a first embodiment of the present invention. Figure 22 yes Figure 21A cross-sectional view of the heat exchanger tube 102 in the diagram. For clarity, only one heat exchanger tube is shown as an example. See also: Figure 21 and Figure 22 As can be clearly seen in the figure, the heat exchanger core 102 includes an upper tube sheet 122, a lower tube sheet 123, a wound core 124 connected to the center of the lower tube sheet 123, and a heat exchange tube 121 wound in a spiral shape. The heat exchanger core 102 also includes a retaining plate 125, through which the lower ends of the heat exchange tube 121 and the wound core 124 pass. The retaining plate 125 is used to prevent the heat exchange tube 121 and the wound core 124 from shaking due to the scouring of the fluid medium in actual use.

[0095] As can also be seen in the figure, the heat exchange tube 121 includes a first hollow tube 1211 and a second hollow tube 1212. The upper end of the first hollow tube 1211 extends out of the second hollow tube 1212 and is sealed to the upper tube sheet 122. The upper end of the second hollow tube 1212 is sealed to the lower tube sheet 123. The lower end of the first hollow tube 1211 and the lower end inner wall of the second hollow tube 1212 are spaced apart to prevent the lower end of the first hollow tube 1211 from contacting the lower end inner wall of the second hollow tube 1212 after it expands axially due to heat during actual operation.

[0096] Simultaneously refer to Figure 2 and Figure 21 In use Figure 6-20 When the heat exchange tube with a long axis and a short axis in the cross section of at least the second hollow tube shown is wound into a heat exchange tube with a spiral portion according to the present invention, the long axis of the cross section of the heat exchange tube is usually set to be parallel to the flow direction of the second fluid medium, that is, parallel to the axial direction of the heat exchanger, in order to reduce the flow resistance of the second fluid medium and the stagnation area behind the tube, thereby improving the heat exchange efficiency.

[0097] Figure 23 This is a front sectional view of the heat exchanger core used in a heat exchanger according to a second embodiment of the present invention. The difference between the heat exchanger core 202 used in the second embodiment and the heat exchanger core 102 used in the first embodiment is that the heat exchanger core 202 in the second embodiment does not include a retaining plate, and the lower ends of the heat exchange tube 221 and the lower ends of the wound core 224 are kept as free ends. Figure 22 Although the heat exchange tube 221 is shown to include a transition section and a straight section between the middle spiral part and the free end, the straight section may also be omitted since the retaining plate is not included.

[0098] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A heat exchange tube comprising: The first hollow tube comprises an open first end and a second end, and the second hollow tube comprises an open end and a closed end. The first hollow tube is built in the second hollow tube, a gap is formed between the outer wall of the first hollow tube and the inner wall of the second hollow tube, and the first end of the first hollow tube extends out of the open end of the second hollow tube. The second end of the first hollow tube is spaced apart from the inner wall of the closed end of the second hollow tube. The part of the second hollow tube of the heat exchange tube between the open end of the second hollow tube and the second end of the first hollow tube is spirally wound around a center, The first hollow tube comprises a support member extending from the outer wall of the first hollow tube, and the extending end of the support member is floatingly abutted against the inner wall of the second hollow tube, for maintaining the gap between the first hollow tube and the second hollow tube. The cross section of the second hollow tube comprises a long axis and a short axis. The support member is a bolt-nut assembly, the bolt penetrates into and extends out of the first hollow tube along the short axis, and is retained on the first hollow tube by the nut. Or the support member is a rib plate fixed on and extending out of the outer wall surface of the first hollow tube, and the rib plate is in the form of discrete segments in the axial direction of the heat exchange tube.

2. The heat exchange tube of claim 1, wherein, The cross section of the first hollow tube and the second hollow tube are both biaxially symmetrical, and the biaxial axes of the first hollow tube and the second hollow tube are overlapped with each other. At least a part of the end of the cross section of the first hollow tube and the second hollow tube along one of the symmetrical axes is overlapped with each other.

3. The heat exchange tube of claim 1, wherein, The cross section of the first hollow tube is smaller than the cross section of the second hollow tube.

4. The heat exchange tube according to any one of claims 1 to 3, wherein The cross section of the first hollow tube comprises a long axis and a short axis.

5. A heat exchanger tube core, comprising an upper tube plate and a lower tube plate, the upper tube plate and the lower tube plate respectively comprising through holes; a winding core body extending in the axial direction, the upper end of the winding core body being fixed to the center of the lower tube plate; and a heat exchange tube layer, at least one heat exchange tube being included in one heat exchange tube layer, the heat exchange tube being the heat exchange tube according to any one of claims 1-4, the heat exchange tubes in each layer being arranged in a spiral around the winding core body as the center with the same spiral radius and spiral angle, the first end of the first hollow tube of the heat exchange tube penetrating through and being sealingly connected with the through hole in the upper tube plate, the open end of the second hollow tube of the heat exchange tube penetrating through and being sealingly connected with the through hole in the lower tube plate, and the lower end of the heat exchange tube being a free end.

6. The heat exchanger tube core of claim 5, wherein, The winding directions of the heat exchange tubes in adjacent heat exchange tube layers are opposite, and the lengths of the heat exchange tubes are substantially consistent.

7. The heat exchanger tube core of claim 5 or 6, wherein, The open end of the second hollow tube of the heat exchange tube extends and is open between the upper tube plate and the lower tube plate, and the parts of the first hollow tube and the second hollow tube between the upper tube plate and the lower tube plate are straight tube segments.

8. The heat exchanger tube core of claim 5 or 6, wherein, The heat exchange tube comprises, in sequence, a straight tube segment and a transition tube segment between the lower tube plate and the part of the heat exchange tube that is spirally wound.

9. The heat exchanger tube core of claim 8, wherein, The heat exchanger tube core further comprises a retaining plate fixed to the shell, the retaining plate comprising heat exchange tube through holes with the same cross-sectional shape as the second hollow tube, the heat exchange tube comprising, in sequence, a transition tube segment and a straight tube segment between the part of the heat exchange tube that is spirally wound and the free end, the straight tube segment penetrating through and being gap-fitted with the heat exchange tube through hole on the retaining plate.

10. The heat exchanger tube core of claim 8, wherein, The heat exchanger tube core further comprises a retaining plate fixedly connected to the lower end of the wound core and the lower end of the heat exchange tube respectively, and the retaining plate is movable with the lower end of the wound core and the lower end of the heat exchange tube when the lower end of the wound core and the lower end of the heat exchange tube freely expand due to heat.

11. The heat exchanger tube core of claim 5 or 6, wherein, The long axis of the heat exchange tube is arranged parallel to the central axis of the wound core.

12. A heat exchanger comprising: The shell extends in the longitudinal direction and comprises a first fluid medium inlet and a first fluid medium outlet, a second fluid medium inlet and a second fluid medium outlet; and the heat exchanger tube core according to any one of claims 5-11 is arranged in the shell and is sealingly connected to the shell by the upper tube sheet and the lower tube sheet, wherein the first fluid medium inlet is in fluid sealing communication with the first end of the first hollow tube, the first fluid medium outlet is in fluid sealing communication with the open end of the second hollow tube, the first fluid medium inlet, the first end of the first hollow tube, the inner cavity of the first hollow tube, the second end of the first hollow tube, the gap between the first hollow tube and the second hollow tube, the open end of the second hollow tube and the first fluid medium outlet form a first fluid medium channel, the second fluid medium inlet and the second fluid medium outlet form a second fluid medium channel with the shell, which is sealingly isolated from the first fluid medium channel, and the portion of the heat exchange tube below the lower tube sheet extends into the second fluid medium channel.

13. The heat exchanger of claim 12, wherein, The first fluid medium inlet is arranged on the shell above the upper tube sheet, the first fluid medium outlet is arranged on the shell between the upper tube sheet and the lower tube sheet, the second fluid medium outlet is arranged on the shell corresponding to the free end of the heat exchange tube, and the second fluid medium inlet is arranged immediately below the lower tube sheet.

14. The heat exchanger of claim 12 or 13, wherein, The heat exchanger comprises at least two first fluid medium outlets, which are uniformly spaced on the shell between the upper tube sheet and the lower tube sheet.

15. A method of manufacturing a heat exchanger tube core or a heat exchanger, the heat exchanger tube core or heat exchanger comprising at least one heat exchanger tube layer, each heat exchanger tube layer comprising at least one heat exchanger tube, the heat exchanger tube comprising: The first hollow tube comprises an open first end and a second end, and the second hollow tube comprises an open end and a closed end, the first hollow tube is arranged inside the second hollow tube, a gap is formed between the outer wall of the first hollow tube and the inner wall of the second hollow tube, and the first end of the first hollow tube extends out of the open end of the second hollow tube, the second end of the first hollow tube is spaced apart from the inner wall of the closed end of the second hollow tube, The manufacturing method comprises: a) the open end of the second hollow tube of the heat exchange tube in the innermost layer of heat exchange tubes is passed through and sealingly connected to the corresponding through hole on the lower tube sheet of the heat exchanger tube core or the heat exchanger; the second end of the first hollow tube of the heat exchange tube is inserted into the second hollow tube to a suitable position to form a required sleeve, wherein the first hollow tube comprises a support, the support extends from the outer wall of the first hollow tube, the extending end of the support floatingly abuts the inner wall of the second hollow tube, and the support is used to maintain the gap between the first hollow tube and the second hollow tube, the cross section of the second hollow tube comprises a long axis and a short axis, the support is a bolt-nut assembly, the bolt is inserted into and extends out of the first hollow tube along the short axis and is retained on the first hollow tube by the nut, or the support is a rib plate fixed to and extending from the surface of the outer wall of the first hollow tube, and the rib plate is in the form of discrete segments in the axial direction of the heat exchange tube. b) winding the portion of the sleeve formed in step a) intermediate the open end of the second hollow tube and the second end of the first hollow tube around the winding core into a spiral; c) forming a desired sleeve of heat exchange tubes according to step a); d) winding the portion of the sleeve in step c) intermediate the open end of the second hollow tube and the second end of the first hollow tube around the winding core and the heat exchange tubes already wound into a spiral; e) repeating steps c) - d) until the heat exchange tubes in the last heat exchange tube layer are disposed; f) passing the first end of the first hollow tube of all heat exchange tubes through a corresponding through hole in the heat exchanger tube core or the upper tube sheet of the heat exchanger and sealingly connecting therewith.

Images