EP3022510A1

EP3022510A1 - Heat exchanger having an elastic element

Info

Publication number: EP3022510A1
Application number: EP14739358.1A
Authority: EP
Inventors: Markus Hammerdinger; Christoph Seeholzer
Original assignee: Linde GmbH
Current assignee: Linde GmbH
Priority date: 2013-07-16
Filing date: 2014-07-10
Publication date: 2016-05-25
Also published as: US9874410B2; RU2016104903A; US20160370130A1; RU2016104903A3; WO2015007375A1; CN105518410A

Abstract

The invention relates to a heat exchanger (1) for indirectly transferring heat between a first and a second fluid, comprising a shell (10), which surrounds a shell space (M) for accommodating a first fluid, a tube bundle (2), which is arranged in the shell space (M) and which has a plurality of tubes (20) for accommodating the second fluid, wherein the tubes (20) are arranged in a plurality of tube layers (200, 201, 202), and a jacket (3), which is arranged in the shell space (M) and which encloses an tube layer (200) of the tube bundle (2) that is outermost in a radial direction (R) of the tube bundle (2), such that an intermediate space (4) that surrounds the tube bundle (2) is formed between the tube bundle (2) and the jacket (3), wherein according to the invention at least one elastic element (5, 5') having a first region (50a) is arranged between adjacent tube segments (200', 200") in the outermost tube layer (200), wherein the at least one elastic element (5, 5') has a second region (50b), which protrudes from the outermost tube layer (200) and which is designed to contact an inside (3a) of the jacket (3) facing the tube bundle (2) or to connect the at least one elastic element (5, 5') to the jacket (3).

Description

description

Heat exchanger with elastic element

The invention relates to a heat exchanger according to claim 1 and its use.

Such a heat exchanger has a pressure-bearing jacket, which delimits a jacket space for receiving a first fluid. In the jacket space, a tube bundle is arranged with a plurality of tubes for receiving a second fluid, wherein the tubes are arranged in a plurality of tube layers, so that the second fluid can enter into an indirect heat exchange with the guided in the shell space first fluid. Furthermore, such a heat exchanger has a arranged in the shell space and the tube bundle surrounding shirt, so that between the tube bundle and the shirt as small as possible, the tube bundle surrounding space is formed. The arrangement of such a shirt around the

Tube bundle around is to suppress an excessive bypass flow of the first fluid past the tube bundle, which adversely affect the effectiveness of the

Heat exchanger would affect. In certain cases, however, it may be necessary for the shirt to require a greater distance from the tube bundle of the heat exchanger due to operational temperature conditions. This enlarged space serves to temperature-induced movements of the

Tube bundle and the shirt to compensate.

From EP 1 790 932 A1 a coiled heat exchanger of the beginning

described type having an elastic member which is disposed between the shirt and the outer tube layer, wherein the elastic member is applied to the outermost layer of pipe. The elastic component makes it possible to reduce a thermally induced voltage by decoupling the thermal diameter change of the tubes and the shirt. Due to the arrangement of the prior art elastic components on the outermost layer of pipe a corresponding space between the shirt and the outermost Pipe layer present, which is due to the dimensions of the elastic member in the radial direction of the tube bundle.

The problem here is, however, that the gap between the shirt and the outermost layer of pipe allows an undesirable bypass flow of the shell-side first fluid past the tube bundle, this part not or only to a small extent on the heat exchange with the second fluid, which is guided in the tube bundle participates. This can lead to a significant impairment of the heat exchanger.

For example, in the case of a falling film evaporator, too large a bypass flow can lead to an increased liquid accumulation in the sump of the heat exchanger. If the liquid level rises too high, the performance of such must

Heat exchanger reduced or the liquid (first fluid) are withdrawn from the system, in particular to prevent a system shutdown.

Proceeding from this, the present invention is therefore based on the problem, a heat exchanger of the type mentioned in such a way that the aforementioned disadvantages are mitigated.

This problem is solved by a heat exchanger with the features of claim 1.

Thereafter, it is provided that at least one elastic element in sections, i. with a first region disposed between adjacent tube sections in the outermost tube layer, the at least one elastic element having a second region projecting out of the outermost tube layer along the radial direction of the tube bundle, and wherein the at least one elastic element with its standing out of the outermost tube layer second region on the tube bundle or the outermost layer of tube facing the inside of the shirt is applied or is formed. Alternatively or additionally, that area serves to connect the elastic element to the shirt.

An "outermost layer of the tube bundle" is to be understood in particular as the tube layer which is adjacent to the shirt and in the radial direction of the Tube bundle the smallest distance - compared to the other pipe layers of the tube bundle - to the shirt has.

The temperatures of the first and second fluids require - e.g. due to thermal changes in the diameter of the tubes and the shirt - thermally induced stresses between the tube bundle, in particular the outermost one

Pipe layer, and the shirt. The at least one elastic element allows a decoupling of these thermal changes in diameter of the tubes and the shirt, so that these voltages can be reduced or prevented. The inventive integration of the at least one elastic element in the outermost layer of the heat exchanger, the gap between the outermost layer of tubes and the inside of the shirt, which is formed by the at least one elastic element, can be made substantially smaller than in the prior art and still the provide the required distance for thermal expansion. This is made possible by the fact that the assembly is no longer carried out on the outermost Läge of the heat exchanger, but in the outermost layer of the heat exchanger, whereby the required for the installation path or space, which does not participate in the elastic deformation, not dead Gap remains on the outermost layer of pipe.

In particular, the at least one elastic element is a so-called non-heat-transmitting element in the sense that the at least one elastic element is not in direct contact with both fluids (such as the tubes of the tube bundle).

If, for example, the first fluid, which inter alia contacts the shirt, has a low temperature, the shirt contracts and enters

Interaction with the at least one elastic element. The at least one elastic element is designed so that it - elastically deformed due to the force acting on the at least one elastic element by the contraction of the shirt - in return, the shirt has little or no deformation at the points on which it is in

Interaction with the at least one elastic element occurs (the same applies to the tube bundle or its tubes). This is a thermally induced

Power transmission (due to the described thermal diameter change) prevents or reduces between the tubes and the shirt because the shirt does not or only to a relatively small extent with the tubes of the outermost layer of tubes interacts. Thus, damage to the

Heat exchanger, such as a tearing of the shirt prevented.

The arrangement of the at least one elastic element between adjacent pipe sections - these are in particular next adjacent pipe sections of a tube of the outermost layer of pipes - allows the provision of a gap, with a comparatively smaller volume, without affecting the requirements for the design of the at least one elastic element must be reduced. The arrangement of at least one

elastic element thus takes place - in other words - at least in sections within the outermost layer of the tube, i. a first region of the at least one elastic element is arranged in the first tube layer while a second region of the at least one elastic element is radially out of the outermost tube layer. This has the advantage that a bypass flow of the shell-side first fluid past the tube bundle (due to the lower

Space volume) is decreased so that the efficiency of heat exchange of the shell-side first fluid with the second fluid flowing through the inside of the tubes is less affected.

According to the invention, the tubes of the tube bundle are wound in several tube layers around a core tube of the heat exchanger, that is, in which

Heat exchanger to a so-called wound heat exchanger. The

Core tube extends generally along a longitudinal axis, which preferably extends along the vertical with respect to a condition of the heat exchanger arranged as intended. Preferably, the jacket of the

Heat exchanger along this longitudinal axis, which forms in particular a cylinder axis of the shell.

Preferably, in each case at least one spacer element is arranged between pipe layers adjacent in the radial direction of the tube bundle. In the present case, "radial direction" is understood to mean that direction which runs along the radius of the core tube or tube bundle and is perpendicular to the longitudinal axis or vertical and points away from it. By "adjacent pipe sections of the outermost layer of pipes" is meant, in particular, those sections of the same pipe or two pipes of the outermost layer of pipes which are adjacent to one another along the longitudinal axis and which lie next to one another, ie between two each Such pipe sections along the longitudinal axis of the heat exchanger or core tube no further pipe section is arranged, but possibly one of

elastic elements according to the invention (see above).

An "elastic element" is understood according to the invention to mean an element or component whose capability for reversible deformation (deformation) is greater (in the sense that a smaller force is necessary to achieve elastic deformation) than that of the adjacent components, In particular, the tubes, the shirt or the spacer elements.When there is an interaction of the elastic element with the shirt is always a reversible elastic

Deformation of the elastic member, wherein the shirt (or other components interacting with the elastic member, such as the spacers and / or the tubes of the outermost layer of tubing) undergoes no or substantially less elastic deformation through interaction with the at least one elastic member. Temperature-induced expansions / contractions of these components are possible, only an interaction with the elastic element leads to no or only a small deformation in the region of the interaction or the contact. The reversibility makes it possible that the at least one elastic element adjoining the shirt at a

temperature induced deformation, e.g. contraction of the shirt, can elastically deform and can go back to the non-deformed original state in a reversal of temperarturbedingten deformation.

The necessary deformation force to achieve a reversible deformation of the at least one elastic element is thus less than the necessary

Deformation force for a corresponding deformation of the tubes, the shirt or the spacer elements. This allows a heat-related relative movement between the tube bundle and shirt, in which the distance between the shirt and the outermost layer of pipe changes and thus the said gap varies in volume. According to the invention, "elastic" is understood as meaning both a linear elasticity and a non-linear elasticity (eg rubber elasticity). "Elasticity" is understood in particular to mean an elasticity which is also at temperatures of -196 ° C. to 100 ° C., especially -165 to 65 ° C is present. The elastic element is thus elastic, in particular at these temperatures, and can perform the above-described reversible deformation.

In some embodiments, the spring constant of the at least one elastic member is preferably less than 80%, preferably less than 50%, preferably less than 10%, or more preferably less than 1%, as the spring constant of the tubes, spacers, or shirt.

The at least one elastic element may be positively, positively and / or materially connected to the shirt. Furthermore, the at least one elastic element, via a spacer element, which is arranged between the outermost layer of pipes and the adjacent pipe layer, be fixed to the tube bundle, in particular form-fitting, non-positively and / or materially. Thus, e.g. the at least one elastic element be welded to the shirt and the spacer element. In principle, it is possible for the at least one elastic element to be either slidably connected to the shirt or to the spacer only, i.e., to abut against these components, allowing for further decoupling of the tube bundle from the surrounding shirt. Preferably, the distance between the outer tube layer and the inside of the shirt (i.e., the thickness of the gap) is in a range of 1 mm to 10 mm.

It is also conceivable that the at least one elastic element is designed to extend longitudinally (ie has a greater extent along a direction of longitudinal extension than perpendicular to it), wherein it is between two

Pipe sections of the tube bundle and along those pipe sections in his

Longitudinal direction extends. Here, the elastic element

especially the core tube revolve, which has the advantage of a more extensive Suppression of a bypass flow of the first fluid on the tube bundle has over.

Basically, the elastic element as a screw, leaf, or

Disc spring or be designed as another spring element or such

Have elements. Furthermore, the elastic element may be spherical or cylindrical, e.g. in the form of a solid or hollow body.

In one embodiment of the invention, the at least one elastic element has two limbs connected to one another via a base, each having an end region, wherein those end regions rest against the inside of the shirt. Preferably, the legs diverging from the base in the direction of the shirt apart and in particular enclose an angle of 30 ° to 50 °, preferably 40 °, wherein that angle increases with elastic deformation of the elastic element, which reduces the expansion of the elastic element normal to the shirt.

Preferably, the at least one elastic element is fixed via the base to that at least one spacer element, in particular via a

Welded connection, wherein a connection with the shirt can be done by means of clamping. The legs are partially out of the outermost layer of pipe out, wherein those portions of the legs form the protruding from the pipe layer region of the elastic element. Furthermore, the legs can be integrally formed on the base together. Furthermore, the end regions are preferably convexly curved toward the shirt, so that they each form a convexly curved contact surface for the shirt.

Both legs of the elastic element may in turn be formed longitudinally along the above-defined longitudinal extension direction in order to suppress a bypass flow.

Preferably, the at least one elastic element comprises a metal and / or a plastic, in particular the at least one elastic element comprises a stainless steel, eg according to the standard EN 10020, in particular one Stainless steel spring steel of material number 1.4310, and / or PTFE (polytetrafluoroethylene), eg Teflon, on.

Preferably, the heat exchanger has a plurality of elastic elements, which are each arranged in sections between adjacent pipe sections of the outermost layer of pipes, that are integrated into the outermost layer of pipes, wherein the respective elastic element in the radial direction of the tube bundle from the outermost layer of pipe standing out area Plant on the tube bundle facing the inside of the shirt of the heat exchanger, wherein that area alternatively or additionally also for connecting the respective elastic

Elementes can be formed with the shirt. The individual elastic elements can in turn be designed as described above.

Preferably, along the circumference of the tube bundle or along the

Longitudinal direction of a tube of the tube bundle several

elastic elements according to the invention arranged side by side. Furthermore, a plurality of elastic elements according to the invention are preferably arranged one above the other along the longitudinal axis of the heat exchanger, so that the elastic elements are distributed in particular substantially uniformly over the outermost layer of pipes.

The heat exchanger according to the invention is preferably used for carrying out an indirect heat exchange between a refrigerant flow as a first fluid and a hydrocarbon-containing stream as a second fluid, wherein in particular the hydrocarbon-containing stream is formed by natural gas.

Further details and advantages of the invention will become apparent from the following

Figure description of an embodiment illustrated by the figures.

Show it:

Fig. 1 is a partial sectional view of an inventive

heat exchanger; Figure 2 is a partially sectioned perspective view of a wound heat exchanger with elastic elements according to the invention. and

Fig. 3 shows a cross section of an embodiment of an elastic element according to the invention.

FIG. 1 shows, in connection with FIG. 2, an inventive device

Heat exchanger 1 with a plurality of elastic elements. 5

The heat exchanger 1 is designed for indirect heat transfer between a first and a second fluid and has a jacket 10 which has a

Mantle space M for receiving the first fluid surrounds, which can be introduced via an inlet port 101 on the jacket 10 in the shell space M and via a corresponding outlet port 102 on the shell 10 again from the shell space M is removable.

In this case, the jacket 10 extends along a longitudinal axis L which, relative to a conditionally arranged state of the heat exchanger 1, extends along the vertical. In the shell space M, a tube bundle 2 is further arranged with a plurality of tubes 20 for receiving the second fluid. In this case, the tubes 20 in several tube layers 200, 201 helically wound around a core tube 21 (the

For clarity, only the outermost layer of tubes 200 and the underlying tube layer 201 are shown in Fig. 1), wherein the core tube 21 also extends along the longitudinal axis L and is arranged concentrically in the shell space M. A plurality of tubes 20 are each combined in a tube plate 104, wherein the second fluid can be introduced via inlet stub 103 on the jacket 10 into those tubes 20 and can be withdrawn from the tubes 20 via outlet stub 105. Thus, heat can be transferred indirectly between the two fluids, which are preferably conducted in countercurrent through the heat exchanger 1. The jacket 10 and the core tube 21 are at least partially cylindrical, so that the longitudinal axis L forms a cylinder axis of the shell 10 and concentric core core 21 extending therein. In the shell space M, a shirt 3 is further arranged, which surrounds the tube bundle 2, so that between the tube bundle 2 and that shirt 3 a tube bundle 2 surrounding

Interspace 4 is formed. The shirt 3 serves a bypass flow of the in Mantle space M guided first fluid, with which the tube bundle 2 is acted on the tube bundle 2 over as possible to suppress. The first fluid is thus guided in the jacket space M in the region of the jacket space M surrounded by the shirt 3. Furthermore, the individual pipe layers 200, 201 (in particular with horizontal support of the tube bundle 2) extend along the longitudinal axis L extended spacer elements 61, 6 to each other or on the core tube 21, wherein in each case a plurality of spacer elements 61, 6 in the radial direction R of the tube bundle. 2 are arranged one above the other.

For decoupling of thermal stresses / movements of the shirt 3 and the tubes 20 and the tube bundle 2 against each other are more elastic

Elements 5 are provided (in FIG. 2, three such elements 5 are shown by way of example), which are respectively integrated into the outermost layer of pipes 200, wherein the elastic elements 5 are preferably distributed substantially uniformly over the first layer of pipes 200. The elastic elements 5 are each arranged with a first region 50a between tube sections 200 ', 200 "of the outermost tube layer 200 adjacent to the longitudinal axis L, wherein in each case a second region 50b of the respective elastic element 5 which abuts against the tube bundle 2 facing inside of the shirt 3 (or for connection to the shirt 3), in the radial direction R of the tube bundle 2 and the core tube 21 from the outermost layer of tubes 200 in the direction of the shirt 3 is out.

The elastic elements 5 are in each case preferably fixed to an outermost spacer element 61 in the radial direction R, in particular via a

Welded, and abut on the respective second portion 50b slidably on the inside of the shirt 3. Other attachments on the shirt 3 and / or on the respective spacer 61 are also possible (see above). The outermost ply layer 200 has a distance D (relative to a non-operating state) to the inside of the shirt 3 along the radial direction R, which is in particular in a range of 2 mm to 10 mm and the usually occurring heat-induced movements of the shirt 3 and the tube bundle 2 against each other during operation of the heat exchanger 1 allowed. The arrangement of the elastic members 5 between the inside of the shirt 3 and the respective outermost spacer 61 allows sufficient

Decoupling of the outermost layer of pipes 200 and the tube bundle 2 on the one hand and the shirt 3 on the other hand, which allows a reduction of heat-induced stresses while keeping the thickness of the gap 4 as small as possible.

Figure 3 shows a further embodiment of an elastic element 5 'according to the invention, e.g. Instead of the elastic element 5 in a heat exchanger 1 according to Figure 2 can be used. According to FIG. 3, the elastic element 5 'has two limbs 52, 53 integrally formed with one another via a curved or rounded base 51, each having an end region 52a, 53a, wherein those end regions 52a, 53a each have a convex contact surface for engagement with the inside 3a of the shirt 3. In doing so, the legs 52, 53 extend apart from the base 51, by which they are secured to the spacer layer 61 (e.g., by a welded joint or clamp between shirt 3 and spacer 61), towards the shirt 3. Here, the legs 51, 52 may have an angle W of e.g. 40 °. The thickness of the legs 52, 53 may be between 0.3 mm and 0.5 mm, in particular 0.4 mm. The base 51 of the elastic element 5 'is thus between adjacent ones

Pipe sections 200 ', 200 "of the outermost pipe layer 200 and disposed in the outermost layer of pipes 200 and belongs to the first region 50a of the elastic

Elements 5 ', while those end portions 52a, 53a of the legs 52, 53 belong to the protruding second portion 50b of the elastic element 5'. The elastic element 5 'may have a height H in the radial direction R of the tube bundle 2 of e.g. 20 mm to 35 mm, preferably 28 mm.

Upon a force applied to the elastic element 5 '- e.g. because of a

Contracting of the Shirt 3 - there is a reversible, elastic deformation of the elastic element 5 ', in which the legs 52, 53 move away from each other, so that the free end portions 52a, 53a in opposite directions on the inside 3a of the shirt 3 slide along , In a fall in the

temperament-related contraction of the shirt 3, the elastic element 5 'moves back towards its original state. Thus, a decoupling of the thermal movements of the shirt and the tubes 20 takes place. LIST OF REFERENCE NUMBERS

1 heat exchanger

2 tube bundles

3 shirt

4 space

5, 5 'elastic element

6, 61 spacers

10 coat

20 tubes

21 core tube

50a First area

50b Outstanding second area

51 base

52 thighs

53 thighs

52a end area

53a end area

101 inlet nozzle

102 outlet nozzle

103 inlet nozzles

104 tubesheet

105 outlet

200, 201 pipe layers

200 ', 200 "adjacent pipe sections

D distance between shirt and utmost

pipe layer

H height

R radial direction

L longitudinal axis

M shell space

W angle

Claims

Patent claims

Heat exchanger for indirect heat transfer between a first and a second fluid

- a jacket (10) which surrounds a jacket space (M) for receiving the first fluid,

- A tube bundle (2) arranged in the jacket space (M) with a plurality of tubes (20) for receiving the second fluid, the tubes (20) in several tube layers (200, 201, 202) around a core tube (21) of the tube bundle (2) are wrapped and

- a shirt (3) arranged in the jacket space (M), which encloses an outermost tube layer (200) of the tube bundle (2) in the radial direction (R) of the tube bundle (2), so that between the tube bundle (2) and that shirt ( 3) an intermediate space (4) surrounding the tube bundle (2) is formed, characterized in that at least one elastic element (5, 5') with a first region (50a) between adjacent tube sections (200', 200") in the outermost

Pipe layer (200) is arranged, the at least one elastic element (5) having a second region (50b) which protrudes from the outermost pipe layer (200) and which rests against one of the pipe bundles

(2) facing the inside (3a) of the shirt (3) and / or for connecting the elastic element (5) to the shirt

(3) is trained.

Heat exchanger according to claim 1, characterized in that the core tube (21) extends along a longitudinal axis (L), which - based on a properly arranged state of the heat exchanger (1) - runs in particular along the vertical (Z), that radial direction (R) is oriented perpendicular to the longitudinal axis (L).

Heat exchanger according to one of the preceding claims, characterized in that the heat exchanger (1) has at least one

Spacer element (61) between the outermost tube layer (200) and the tube layer (201) adjacent in the radial direction (R) of the tube bundle (2), the at least one elastic element (5, 5 ') on the at least one spacer element (61) is fixed and / or rests against it, in particular further spacer elements (6) between in radial

Direction (R) adjacent pipe layers are provided, which are arranged under the at least one spacer element (61) to support the individual pipe layers (200, 201) in the radial direction (R) of the pipe bundle (2).

4. Heat exchanger according to one of the preceding claims, thereby

characterized in that the at least one elastic element (5, 5') extends longitudinally in the outermost tube layer (200) and in particular revolves around the core tube (21), in particular revolves helically.

5. Heat exchanger according to one of the preceding claims, thereby

characterized in that the at least one elastic element (5, 5') is designed as a spring element, in particular in the form of a helical, spiral or leaf spring.

6. Heat exchanger according to one of the preceding claims, thereby

characterized in that the at least one elastic element (5 ') has two legs (52, 53) connected to one another via a base (51), each with an end region (52a, 53a), those end regions (52a, 53a) leading to the second region ( 50b) and rest against the inside (3a) of the shirt (3), in particular the legs (52, 53) diverging from the base (51), which belongs to the first area (50a), and in particular that elastic element (5 ') is fixed via the base (51) to that at least one spacer element (61).

7. Heat exchanger according to one of claims 1 to 5, characterized in that the at least one elastic element (5) is spherical or cylindrical.

8. Heat exchanger according to one of the preceding claims, thereby

characterized in that the at least one elastic element (5, 5') has a metal, in particular a stainless steel, and/or a plastic, in particular PTFE.

9. Heat exchanger according to one of the preceding claims, thereby

characterized in that a plurality of elastic elements (5, 5 ') is provided, each of which is arranged with a first region (50a) between adjacent pipe sections (200', 200") in the outermost pipe layer (200), the respective elastic element (5, 5') being one of the outermost pipe layers (200 ) has a protruding second area (50b) which rests against an inside of the pipe bundle (2).

Shirt (3) and / or for connection to the shirt (3), and in particular several of the elastic elements (5, 5 ') are arranged one above the other along the longitudinal axis (L).

10. Use of a heat exchanger according to one of claims 1 to 9 to carry out indirect heat exchange between one

Refrigerant stream as the first fluid and a hydrocarbon-containing stream as the second fluid, in particular the hydrocarbon-containing stream being natural gas.