JP4573183B2 - Multi-tube heat exchanger - Google Patents

Abstract

A tube bundle heat exchanger has at least one channel that carries a heating or cooling medium, whereby the tubes of the tube bundle extend essentially axis-parallel to the channel longitudinal axis through the channel. The heating or cooling medium is directed through alternating rings and discs fastened to the respective jacket walls of the channel, in a zigzag pattern as seen in the axial direction of the channel. The channel has an essentially annular cross section. In at least one channel, the rings and discs accommodate and position all the tubes of one channel, each by means of cylindrical recesses, and the perimeter contour of the rings and discs on the medium flow-through side follow the mid-points of the outermost or innermost tube bundle tubes. The perimeter contour includes a web that surrounds all of the outermost or innermost tubes.

Description

The present invention is a multi-tube heat exchanger having at least one passage provided concentrically about a passage longitudinal axis and leading a heating medium or a cooling medium, the tube group through which the medium to be heated or cooled passes. Pipes extending through the passage parallel to the longitudinal axis of the passage, and the rings and disks alternately attached to the respective peripheral walls defining the passage in the axial direction are not attached to these rings and disks. It is related with what forms the channel | path of the annular cross section which guides a heating medium or a cooling medium zigzag seeing in the axial direction of a channel | path with a surrounding wall .

  For many chemical and petrochemical processes, a multitubular heat exchanger is required in which different gaseous and / or liquid media are flowed on the tube side and the peripheral side (passage side). On the passage side, turning plates (rings and discs) are attached at specific intervals in order to increase the heat transfer efficiency of heat exchange and support the tubes of the tube group of passages. There is a flow of heating or cooling medium directed transverse to the group of tubes or heating surface tubes. Since these flow components can exert pulsating forces on the heated surface tubes, they are excited and mechanically loaded in the worst case, especially by constant vibrations in the resonance range of the tubes.

  The natural frequency of the tube is mainly determined by the tube diameter, the wall thickness of the tube, and the distance between the support points (tube plate supporting the tube, turning plate). The excitation frequency of the medium (heating medium or cooling medium) is related to the speed of the medium and the tube pitch. When the natural frequency of the tube matches the excitation frequency, resonances with uncontrollable amplitudes result, resulting in high mechanical loads and cracks or other mechanical damage risks in the tube.

  The risk of resonance in technical practice is generally eliminated by vibration analysis performed, for example, by the TEMA standard (Tube Heat Exchanger Manufacturers Association standard) or other generally accepted methods. In order to eliminate resonance, it is necessary to reinforce the tube with very short intervals between the support points. Edge tubes, i.e. tubes in the outer or inner peripheral range, are held by every other turning plate, so that on the passage side, the outer tube of the tube group is held by an annular plate or ring, and the inner tube of the tube group is a disc Therefore, the distance between the turning plates is very small, resulting in a high pressure loss on the circumferential side.

  Publications "Process Gas Waste Heat Recovery System for ammonia, methenol, hydrogen and Coal gasification Plants", Deutsche Backcock. A multi-tube heat exchanger having two gas passages and a turning plate is known from Babcock-Borsig, Seite14. The outer tube of the tube group is held by an annular plate on the passage side, and the inner tube of the tube group is circular. It is held by a plate.

  The object of the present invention is to provide a multi-tube heat exchanger that avoids the above-mentioned drawbacks, or to reliably support each tube of the tube group in the passage and to cause mechanical damage of the tube group. It is to prevent tube resonance.

The problem is solved by the features of claim 1. According to this solution, in at least one passage, the ring and disc receive and position all the tubes in the passage by circular notches or holes, with one side edge attached to one peripheral wall. The other edge of the ring and disc, i.e. the peripheral contour, extends along a part of the outer contour of the outermost or innermost tube of the tube group or parallel to the line connecting the centers of these tubes An annulus and disc in the perimeter profile include a banded side that surrounds a portion of the circumference of all outermost or innermost tubes.

  Advantageous configurations of the invention can be seen from the dependent claims.

The solution according to the invention gives a multitubular heat exchanger with the following advantages:
All the tubes of the tube group are securely supported and positioned in the passage, and the frequency of the first harmonic vibration of the tubes is above the excitation frequency in any case due to the medium flow, As a result, no resonance appears in the tubes of the tube group.
Despite the small support spacing of the individual tubes, the pressure loss is not very high.

  Advantageously, the width of the side is at least partly constant as the distance between the outer wall of the tube and the surrounding contour. This means that in the above-mentioned range, the same spacing prevails between the center or outer wall of the outermost or innermost tube and the surrounding contour, which means simplification in terms of structure and manufacture.

  In an advantageous configuration of the invention, the width of the side is 3 to 10 mm. With this arrangement, not only the inner or central tube of the tube group, but also the outermost or innermost tube of the respective passage is received and positioned. In a particularly advantageous configuration, the width of the side is smaller than 3 mm. With this configuration, the maximum passage cross section of the heating medium or the cooling medium is obtained on the circulation side of the ring or the disk.

  The circumferential contour at least partially follows the outer contour of the outermost or innermost tube, resulting in an advantageous ring or disc configuration with respect to manufacturing, remaining flow cross-sections and the like. Advantageously, or more advantageously, the peripheral contour may extend at least partly parallel to the virtual coupling line of the two or more outer or inner tube centers. This is advantageous when there are sufficient flow cross sections in the annulus or disc so that the surrounding contours do not have to follow each pipe cross section.

  If more than one passage is present in a multitubular heat exchanger, two or more passages are provided concentrically with each other. By this means a small heat exchanger is obtained.

  If there are two or more passages, it is advantageous if the ring and disc formed by the peripheral contour are provided in one outer passage or in a plurality of outer passages. By this means, the pressure loss of the heating medium or the cooling medium caused by the ring and the disk as the turning plate is kept small.

  In an advantageous configuration, the tubes of the respective tube groups are formed as U-shaped tubes or straight tubes. Thereby, the heat exchanger according to the invention can be provided with differently configured tube groups and can therefore be used for different use cases.

  It is advantageous to form the rings and / or discs according to the invention in a half-moon shape. This leads to a strong inflow from the side of the tube and thus a high heat transfer, especially in multi-tube heat exchangers (with straight tubes instead of U-shaped tubes).

  In an advantageous configuration, the tubes in the passage on the cross-sectional side are provided with a triangular or quadrangular or other geometric pitch or structure. A triangular pitch or structure is advantageous, especially at the high pressure of the heat exchanger. This is because it provides a tube sheet that is significantly reinforced. A square or other geometric structure or tube pitch is advantageous for intermediate or low pressures.

  Embodiments of the present invention will be described below with reference to the drawings.

  A multi-tube heat exchanger 1 according to the prior art can be seen from FIG. Such a multi-tubular heat exchanger includes one or more heating media or cooling media 20, most often heated gas, through the inlet passage 18 required for various chemical and petrochemical processes. To the gas passages 4 and 5, in which heat or cold is discharged into the tubes 3 of the multiple tube groups 2 or heating surface tubes extending into the passages to be heated or cooled. A liquid or gaseous medium such as water and / or steam is heated or cooled.

  The multitubular heat exchanger according to FIG. 1 has a first gas passage 4 or a vent passage, a second gas passage 5 concentrically in layers in a radial direction around an inlet passage 18 provided in the center. Alternatively, an air passage and an outlet passage 19 follow. The passages 4, 5, 18, 19 have a common longitudinal axis 6 that coincides with the longitudinal axis of the multitubular heat exchanger 1. The cross section of the inlet passage 18 is almost circular as much as possible, and the cross sections of the gas passages 4 and 5 and the outlet passage 19 are substantially circular.

  The heating medium flow or cooling medium flow 20 flowing through the inlet passage 18 at one end of the multitubular heat exchanger 1 is 180 by the tube plate or end plate 17 receiving the tube group 2 at the other end. It is turned and supplied to the first gas passage 4 or the air passage. After passing through the first gas passage 4, a further turn of 180 ° is performed, and the heating medium flow or the cooling medium flow 20 is supplied to the second gas passage 5. Finally, the heating medium flow or the cooling medium flow 20 passes through the second gas passage 5, is further turned by 180 ° by the tube plate 17, and is led out from the heat exchanger 1 through the outlet passage 19.

  In the gas passages 4 and 5, the pipe 3 is turned at specific intervals in order to increase the efficiency of heat transfer or cold transfer between the heating medium or cooling medium 20 and the medium to be heated or cooled by circulating in the pipe 3. Supporting or positioning by a plate is performed. Thereby, the heating medium flow or the cooling medium flow 20 flows laterally or nearly laterally towards the tube 3 without flowing parallel to the tube 3 through the gas passages 4, 5, and thus significantly better heat. Transmission can take place. Rings 9 and discs 10 are alternately provided on the peripheral walls 7 and 8 (inner peripheral wall 7 and outer peripheral wall 8) of both of the gas passages 4 and 5, so that a zigzag heating medium flow or cooling medium flow in the gas passages 4 and 5 is provided. The turning plate is formed so that is formed. The outer tube 3 of the tube group extending into the gas passages 4, 5 is attached by a ring 9 attached to the peripheral wall 8, and the inner tube 3 of the tube group extending into the gas passages 4, 5 is attached to the peripheral wall 7. Supported and positioned by the plate 10. In this case, the tube 3 is supported by the ring 9 or the disc 10 in the axial direction at a support interval S (the interval between the two rings 9 or the two discs 10), and the support portion of the disc 10 is viewed in the axial direction. Each in the middle of the support of the ring 9.

  Starting from this multi-tube heat exchanger according to the prior art, the multi-tube heat exchanger 1 according to the invention comprises a ring 9 and a disc 10 in at least one gas passage 4, 5 as shown in FIG. These rings and discs receive or position all the tubes 3 of the tube group of the gas passages 4, 5 respectively by means of cylindrical notches or holes 11, respectively. Furthermore, according to the present invention, the peripheral contour 12 of the ring 9 and the disc 10 follows the center 14, 15 of the outermost or innermost tube 3 of the tube group on the medium flow side 13, respectively. It includes a side 16 surrounding all the outer or innermost tubes 3.

  As shown in FIGS. 3 to 9, the medium flow side of the ring 9 or the disk 10 is passed through the medium flow 20 and thus heated between the ring 9 and the inner peripheral wall 7 or between the disk 10 and the outer peripheral wall 8. The ring 9 or the side 13 of the disk 10 that forms the free or flow path of the medium flow or cooling medium flow 20.

  The peripheral contour 12 of the ring 9 or the disc 10 on the flow side 13 is not formed in a circle, but according to the invention, as described above, according to the centers 14, 15 of the outermost or innermost tube 3 of the tube group, That is, the peripheral contour 12 of the ring 9 follows the center 15 of the innermost tube 3, the peripheral contour 12 of the disc 10 follows the center 14 of the outermost tube 3, and the peripheral contour 12 is still the ring material or disc material or edge respectively. 16 together so that each tube 3 of the tube group is surrounded by this side 16 (see FIGS. 3-9) and also supports the innermost or outermost tube 3 sideways. Due to the peripheral contour 12 according to the invention, the flow cross section on the flow side 13 of the turning plate, ie on the flow side of the ring 9 and the disc 10, is advantageously kept as large as possible. The width B of the material protrusion or side 16 between the outermost or innermost tube 3 and the peripheral contour 12 is at least partly constant. In another preferred configuration, the width B of the side 16 is 3-10 mm, and in a particularly preferred configuration, the width B of the side 16 is less than 3 mm.

  The peripheral contour 12 of the annulus 9 or disc 10 follows the outer contour of the outermost or innermost tube 3 as shown in FIGS. 5 and 6, and the peripheral contour 12 according to FIGS. In particular, the outer contour of the tube follows a wave shape. FIGS. 7-9 show another advantageous configuration of the invention, in which the peripheral contour 12 is at least partly parallel to the virtual coupling line of two or more outer or inner tube centers 14, 15. It extends. In this case, the width B of the side 16 is defined as the vertical distance between the peripheral contour 12 and the outer wall of the tube 3. By virtue of the above-mentioned advantageous configuration, the ring 9 and the disc 10 according to the invention are simplified on the production side and cheaply produced on the one hand, and on the other hand the passage of the heating or cooling medium on the flow side 13 of the ring 9 or the disc 10. The cross section is maximized.

  The holes 11 or the cylindrical notches 11 formed in the ring 9 and the disk 10 for receiving all the tubes 3 in the gas passages 4 and 5 are arranged so that each tube 3 of the tube group is parallel to the longitudinal axis 6 of the passage. The ring 9 and the disk 10 are formed so as to be received and guided in the respective holes 11. The tube 3 is not fixedly connected to the ring 9 or the disk 10 and can freely extend in the axial direction in the hole 11 during heating in the operating state.

  By means of the invention in which the ring 9 and the disc 10 receive all the tubes 3 of the passages or gas passages 4, 5, respectively, each tube 3 between the two rings 9 or between the two discs 10. The previous support interval S is halved to half the support interval S / 2. This is advantageous on the one hand for the lateral support of the tubes 3 of the tube group. This is because each tube 3 is supported as often as twice as much as the known structure. On the other hand, the arrangement according to the invention is also advantageous with respect to the prevention of resonant vibrations of the tubes 3 and thus with respect to the prevention of large mechanical loads on these tubes 3 caused by the resonant vibrations.

  As is well known, the resonant vibration in the tube 3 is formed when the natural frequency of the tube matches the excitation frequency of the medium or heating medium flow or cooling medium flow 20, and the excitation frequency of the medium is transverse to the flow velocity of the medium. In relation to the components and the tube pitch, the natural frequency of the tube 3 is mainly determined by the tube diameter, the wall thickness of the tube 3 and the spacing of the support points (tube plate 17, ring 9 and disc 10).

  By means of the device according to the invention, the resonance in the multitubular heat exchanger 1 without reducing the mutual spacing of the turning plates or rings 9 and the disc 10 and thus without causing high pressure losses on the passage side or the medium side 20. Can be easily prevented and the tube 3 can be reliably supported. By halving the support spacing, it is possible in some cases to increase the size of the support spacing or reduce the wall thickness of the tube 3 without losing the advantageous effects.

  2 to 4 show the multi-tubular heat exchanger 1 of the present invention configured to have two passages or gas passages 4, 5 provided concentrically with each other in a preferred configuration. As is advantageous when two or more passages or gas passages 4, 5 are present, the ring 9 and the disc 10, which have a peripheral contour 12 and receive all the tubes 3, It is provided in the outer gas passage. This means prevents pressure loss of the medium in the heat exchanger 1. This is because the medium flow 20 in the inner passage 4 where the gas still has a very high temperature and thus has a large volume or high passage velocity, finds more free passage, i.e. a larger flow cross section.

  2 to 6 show a multi-tube heat exchanger 1 according to the invention with a tube group 2 formed from U-shaped tubes 3, the inner tube section of which is a gas passage 4 and the outer tube section of which is a gas passage. 7 to 9, a heat exchanger 1 having a tube group 2 formed from straight tubes 3 is shown. The structural arrangement of these straight tubes 3 in the passages 4 and 5 can be freely formed, unlike the case where the U-shaped tube 3 is provided as viewed across the cross section. Advantageously, the straight tube 3 can be provided on the cross-sectional side in the passages 4, 5 in a triangular or quadrangular or other geometric structure or tube pitch. A triangular tube pitch as shown in FIGS. 8 and 9 is provided for a multi-tube heat exchanger 1 with a high or very high pressure, a square tube pitch according to FIG. Tube pitch is provided for medium and low pressures.

  In the multi-tube heat exchanger 1 having the tube group 2 formed from the straight tubes 3, it is advantageous to form the ring 9 and / or the disc 10 in a half-moon shape (not shown). This results in a stronger lateral flow of the media stream 20 towards the tube 3 and thus a higher heat transfer.

  The multi-tube heat exchanger 1 according to the present invention is not limited to the embodiment described in the above figures.

  The longitudinal cross-sectional view of the multi-tube heat exchanger by a prior art is shown.   The longitudinal cross-sectional view of the multi-tube heat exchanger by this invention is shown.   The fragmentary sectional view by the AA cross section of FIG. 2 is shown.   The fragmentary sectional view by the BB cross section of FIG. 2 is shown.   FIG. 4 shows an enlarged detail view of a range C in FIG. 3.   FIG. 4 shows an enlarged detail view of a range D in FIG. 3.   Fig. 6 shows a tube of a tube group provided in the passage with a similar (but square) geometric structure to Fig. 5;   Fig. 4 shows the tubes of the tube group provided in the passage with a similar (triangular) geometric structure similar to Fig. 3;   FIG. 9 shows an enlarged detail view of range E in FIG. 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multitubular heat exchanger 2 Tube group 3 Tube group tube 4 Passage or gas passage 5 Passage or gas passage 6 Passage vertical axis 7 Passage inner peripheral wall 8 Passage outer peripheral wall 9 Ring 10 Disc 11 Cylindrical notch or hole 12 Surrounding contour 13 Heating or cooling medium flow side 14 Outer tube center 15 Innermost tube center 16 Side 17 Tube plate or end plate 18 Inlet passage 19 Outlet passage 20 Heating medium flow or cooling medium flow

Claims (11)

A multi-tubular heat exchanger having at least one passage (4, 5) provided concentrically around the passage longitudinal axis (6) and guiding the heating or cooling medium, the medium to be heated or cooled The pipes (3) of the pipe group (2) through which the pipes (2) pass extend through the passages (4, 5) parallel to the longitudinal axis of the passages (6), and each peripheral wall (7) defining the passages (4, 5). , 8) are alternately attached to the ring (9) and the disk (10) in the axial direction together with the peripheral wall (8, 7) to which the ring (9) and the disk (10) are not attached. 4 and 5), in which at least one passage (4, 5) is formed with a ring (9) and a disk in a passage having a circular cross section for guiding a heating medium or a cooling medium in a zigzag manner when viewed in the axial direction of (10), by-out circular shaped notches (11) or holes, to each with the passage (4, 5) All tubes (3) are received and positioned, one side edge is attached to one peripheral wall (7 or 8) and the other side edge or peripheral contour (12) of the disc (10) Extending along a part of the outer contour of the outermost or innermost tube (3) of the tube group or extending parallel to the line connecting the centers (14, 15) of these tubes (3), The ring (9) and the disc (10) in the peripheral contour (12) include a banded side (16) surrounding a part of the periphery of all the outermost or innermost tubes (3) A multi-tube heat exchanger. The band width (B) of the strip-shaped side (16) defined as the distance between the outer wall of the tube (3) and the peripheral contour (12) of the ring (9) and the disc (10 ) is constant. The multitubular heat exchanger according to claim 1. Band band width of the sides (16) (B) is characterized in that it is a 3 to 10 mm, multi-tube heat exchanger according to claim 1 or 2. Strip width of the strip edges (16) (B) being less than 3 mm, the multi-tube heat exchanger according to claim 1 or 2. The peripheral contour (12) of the ring (9) and the disc (10) extends in a wavy manner along a part of the outer contour of the outermost or innermost tube (3). The multitubular heat exchanger as described in one of 1-4. The peripheral contour (12) of the ring (9) and the disc (10) extends parallel to the virtual connection line of two or more outer or inner tube centers (14, 15) The multitubular heat exchanger according to claim 1.   7. A multitubular heat exchanger according to claim 1, characterized in that if more than one passage (4, 5) is present, these are provided concentrically with each other. More than one case passages (4, 5) are present, the ring for receiving the formed around the contour (12) and all the tubes (3) (9) and the disk (10), one outer passage (5 Or a multi-tubular heat exchanger according to claim 1, wherein the heat exchanger is provided in a plurality of outer passages.   The multi-tube heat exchanger according to one of claims 1 to 8, characterized in that the tube (3) of the tube group is formed as a U-shaped tube or a straight tube. Ring (9) or disc (10) is characterized in that it is formed in a semicircular, a multi-tube type heat exchanger according to one of claims 1 to 9. Tube in cross-sectional view in the passage (4, 5) (3), characterized in that provided in a triangular or square or other geometric pitch or structures, to one of claims 1 to 10 The multitubular heat exchanger described.

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