WEB DESIGN AND ARRANGEMENT FOR REDUCING A RADIAL DISTRIBUTION FAULT IN A WOUND HEAT EXCHANGER

Abstract

The invention relates to a heat exchanger (1) for the indirect transfer of heat between a first and at least one second medium (M, M′), having a jacket space (I) for receiving the first medium (M), a core pipe (20) arranged in the jacket space (I), a pipe bundle (15) arranged in the jacket space (I), which bundle comprises a plurality of pipes (10) which are each wound around the core pipe (20) such that the pipe bundle (15) has a plurality of pipe layers arranged on top of each other (100, 101, 102, 103) which each comprise at least one pipe (10), a pipe bundle gap (200, 201, 202, 203) being present between all the adjacent pipe layers (100, 101; 101, 102; . . . ) and a plurality of spacers (30) being arranged in each pipe bundle gap (200, 201, 202, 203) to support the pipe layers (100, 101, 102, 103). According to the invention, the spacers (30) each have a thickness (D) in the radial direction (R) of the pipe bundle (15), the thicknesses (D) of the spacers (30) of a first pipe bundle gap (200) each being greater than the thicknesses (D) of the spacers of a second pipe bundle gap (203), which lies further to the outside in the radial direction (R) of the pipe bundle (15) than the first pipe bundle gap (200).

Claims

1.-12. (canceled)

13. A heat exchanger for indirect heat transfer between a first and at least one second medium, having a shell space for receiving the first medium, a core tube arranged in the shell space, a tube bundle arranged in the shell space that has multiple tubes, each of which is wound around the core tube so that the tube bundle has multiple tube layers which are arranged one above the other and each of which has at least one tube, wherein there is a tube bundle gap between every two adjacent tube layers, wherein several spacers for supporting the tube layers are arranged in each tube bundle gap, wherein, the spacers each have a thickness in the radial direction of the tube bundle, wherein the thicknesses of the spacers of a first tube bundle gap are in each case greater than the thicknesses of the spacers of a second tube bundle gap located further outward in the radial direction of the tube bundle than the first tube bundle gap.

14. The heat exchanger according to claim 13, wherein the thicknesses of the spacers which are arranged in the same tube bundle gap are the same.

15. The heat exchanger according to claim 13, wherein the spacers have more than two, in particular three to four, different thicknesses, wherein the thickness of the spacers decreases or remains the same in the radial direction from the core tube to the shell from tube bundle gap to the tube bundle gap.

16. The heat exchanger according to claim 13, wherein the thickness of the spacers decreases in the radial direction from the core tube to the shell from tube bundle gap to tube bundle gap.

17. The heat exchanger according to claim 13, wherein the spacers are designed as longitudinally extending webs, each of which extends in a longitudinal direction.

18. The heat exchanger according to claim 17, wherein the longitudinal direction of the respective spacer runs parallel to the core tube.

19. The heat exchanger according to claim 13, wherein the respective spacer extends along the core tube, at least over an entire length of the tube bundle.

20. The heat exchanger according to claim 13, wherein the spacers are arranged equidistantly to one another in the respective tube bundle gap in the circumferential direction of the tube bundle.

21. The heat exchanger according to claim 13, wherein between an innermost tube layer in the radial direction of the tube bundle and an outer side of the core tube, there is an innermost tube bundle gap in which a plurality of spacers are arranged.

22. The heat exchanger according to claim 13, wherein the spacers are grouped in such a way that a plurality of spacers for supporting the tube layers are arranged one above the other in a radial direction of the tube bundle.

23. The heat exchanger according to claim 13, wherein the number of spacers in the respective tube bundle gap is the same.

24. The heat exchanger according to claim 13, wherein the number of spacers differs in at least two tube bundle gaps.

Description

[0021] The figures show:

[0022] FIG. 1 a partial sectional view of an embodiment of a heat exchanger with spacers of a tube bundle of the heat exchanger that have decreasing thicknesses in the radial direction; and

[0023] FIG. 2 a schematic sectional view of a tube bundle of a heat exchanger according to the invention along a sectional plane which runs perpendicular to the longitudinal axis of the core tube according to FIG. 1.

[0024] FIG. 1 shows an embodiment of a heat exchanger 1 according to the invention. This has a shell 2, which encloses a shell space I of the heat exchanger 1. Arranged in the shell space I is a tube bundle 15 supplied with a fluid phase of a first medium M, which is, for example, a refrigerant, along the longitudinal axis Z of the heat exchanger 1 or shell 2. At least one second fluid medium M′ is conducted in the tubes 10 of the tube bundle 15 so that it can enter into an indirect heat exchange with the first medium M that is conducted in the shell space I. Connecting pieces 3, 4 can be provided in the shell 2 for introducing the first medium M into the shell space I, or for removing the first medium M from the shell space I.

[0025] The tube bundle 15 has a plurality of tubes 10, wherein the tubes 10 are each wound around or onto a core tube 20 arranged in the shell space I, at least sectionally like a helical line, said core tube extending along the longitudinal axis Z so that a plurality of tube layers 101, 102, 103, 104 are formed which lie one above the other in the radial direction R of the tube bundle 15 or of the core tube 20. The radial direction R is in each case orthogonal to the longitudinal axis Z and points outwardly from the longitudinal axis Z toward the shell 2. In order to admit at least one second medium M′ into the tube bundle 15, the tubes 10 are in fluidic connection with at least one connecting piece 5 provided on the shell 2. Furthermore, at least one connecting piece 6 is provided on the shell 2 to withdraw the at least one medium M′ from the tube bundle 15. In order to introduce different second media M′, the tube bundle 15 can also be divided into tube groups, each of which is assigned an inlet or connecting piece 5 and an outlet or connecting piece 6. FIG. 1 shows three such tube groups by way of example.

[0026] Furthermore, the tube bundle 15 can be surrounded by a cylindrical skirt 7 in order to suppress a bypass flow past the tube bundle 15.

[0027] For mechanically stabilizing the tube bundle 15 or the individual tube layers 100, 101, 102, 103, several spacers 30 are provided (see in particular FIG. 2), each arranged in a tube bundle gap 200, 201, 202, 203, wherein the respective tube bundle gap 200, 201, 202, 203 is formed by two adjacent tube layers 100, 101; 101, 102, . . . which lie one above the other in the radial direction R, wherein the innermost tube bundle gap 200 lies between an outer side 20a of the core tube 20 and the innermost tube layer 100.

[0028] The spacers 30 can support the weight of the individual tube layers 100, 101, 102, 103 via the spacers 30. A constant number of spacers 30 are therefore preferably provided in each tube bundle gap 200, 201, 202, 203 so that the spacers 30 can be arranged one above the other in the radial direction R.

[0029] In the prior art, however, said constant number of spacers 30 per tube bundle gap 200, 201, 202, 203 causes the relative reduction of a free cross-sectional area F, that is oriented transversely to the longitudinal axis Z, of the respective tube bundle gap 200, 201, 202, 203 due to the spacers 30 arranged one above the other in the radial direction R to be larger closer to the core tube 20 than in the case of tube bundle gaps located further outwardly. Close to the core tube 20, this leads to a greater pressure drop on the shell space side in the tube bundle 15 than in the case of regions or tube bundle gaps located further to the outside in the radial direction R.

[0030] In order to be able to influence or compensate for this pressure drop in a controlled manner, it is provided according to the invention (see FIG. 2) that the spacers 30 each have a thickness D in the radial direction R of the tube bundle 15, wherein the thicknesses D of the spacers of a first tube bundle gap (e.g. 200) are each greater than the thicknesses of the spacers of a second tube bundle gap (e.g., 201) lying further outward in the radial direction R of the tube bundle 15, i.e., lying closer to the shell 2 than the first tube bundle gap (e.g., 200). The thicknesses of the spacers 30 are preferably of equal size within a tube bundle gap 200, 201, 202, 203.

[0031] According to one embodiment, it can be provided that the spacers 30 have more than two, in particular three to four, different thicknesses D in the radial direction R of the tube bundle 15, wherein the thickness D of the spacers 30 decreases or remains the same in the radial direction R from the core tube 20 toward the shell 2 from tube bundle gap to tube bundle gap. That is, in particular, in each case two or more tube bundle gaps adjacent to each other in the radial direction R can have spacers 30 of the same thickness, and only thereafter is there a decrease in the thickness D so that there will be a stepwise decrease in the thicknesses D to the outside. Alternatively, it can be provided according to FIG. 2 that the thickness D of the spacers 30 decreases in the radial direction from the core tube 20 to the shell 2 from tube bundle gap to tube bundle gap 200, 201; 201, 202; 202, 203.

[0032] The spacers 30 preferably take the form of longitudinally extending webs 30 (see FIG. 1), each extending in a longitudinal direction. The spacers 30 or webs can have a rectangular cross-section perpendicular to the longitudinal direction. It is preferably provided that the longitudinal direction of the respective spacer runs parallel to the core tube 20 or parallel to the longitudinal axis Z. Furthermore, it is preferably provided that the respective spacer 30 extends along the core tube 20 over an entire length of the tube bundle 15.

[0033] In the circumferential direction U of the tube bundle 15, the spacers 30 are arranged in the respective tube bundle gap 200, 201, 202, 203 preferably equidistantly to one another.

[0034] Due to the reduction of the thicknesses D of the spacers 30 in the radial direction R of the tube bundle, the free cross-sectional area F of the further outer tube bundle gaps (e.g., 202, 203) can be reduced or can be matched to the free cross-sectional areas F of the tube bundle gaps (e.g., 200, 201) lying more inwardly, which counteracts the shell-side maldistribution of the first medium or of the refrigerant.

TABLE-US-00001 List of reference signs 1 Wound heat exchanger 2 Shell 3 Connecting piece (inlet) 4 Connecting piece (outlet) 5 Connecting piece (inlet) 6 Connecting piece (outlet) 7 Skirt 10 Tubes 15 Tube bundle 20 Core tube 20a Core tube outer side 30 Spacer 100, 101, 102, 103 Tube layers 200, 201, 202, 203 Tube bundle gap D Thickness I Shell space F Free cross-sectional area M First medium M′ Second medium R Radial direction U Circumferential direction Z Longitudinal axis (vertical)