HEAT EXCHANGER HAVING CHANNELS FOR DAMPING LIQUID MOTIONS

Abstract

A heat exchanger for indirect heat transfer between a first medium and a second medium having a shell which has a shell space to accommodate a liquid phase of the first medium, and at least one heat-exchanger block having first heat-transfer passages to accommodate the first medium and second heat-transfer passages to accommodate the second medium, such that indirect heat can be transferred between the first medium and the second medium. The heat-exchanger block is arranged in the shell space so that it can be surrounded with a liquid phase of the first medium in the shell space. A plurality of cylindrical channels are provided in the shell space laterally to the heat-exchanger block and parallel to each other to conduct the liquid phase of the first medium.

Claims

1. A heat exchanger for indirect heat transfer between a first medium and a second medium, with: a shell, which has a shell space for receiving a liquid phase of the first medium, and at least one heat exchanger block, which has first heat transfer passages for receiving the first medium and second heat transfer passages for receiving the second medium, so that heat can be transferred indirectly between the two media, wherein the at least one heat exchanger block is arranged in the shell space in such a way that it can be surrounded by a liquid phase of the first medium that is located in the shell space, characterized in that a plurality of cylindrical channels for conducting the liquid phase of the first medium that run parallel to one another are provided in the shell space laterally in relation to the at least one heat exchanger block.

2. The heat exchanger as claimed in claim 1, characterized in that the channels are fixed to one another in such a way that they form an interlinked unit, which is in particular formed separately from the at least one heat exchanger block and/or the shell.

3. The heat exchanger as claimed in claim 1, characterized in that the extent of the channels along the longitudinal axis of the respective channel is greater than the greatest inside diameter of the respective channel perpendicularly in relation to the respective longitudinal axis.

4. The heat exchanger as claimed in claim 3, characterized in thatwith respect to the longitudinal axesthe channels have the same length, or in thatwith respect to the longitudinal axesat least some channels have different lengths, in particular to adapt the unit to a curved region of an inner side of the shell.

5. The heat exchanger as claimed in claim 2, characterized in that the respective channel is formed by a hollow profile, in particular the hollow profiles being connected to one another in such a way that the interlinked unit referred to is formed.

6. The heat exchanger as claimed in claim 1, characterized in that the channels are formed by a plurality of interconnected plate-shaped elements, which are connected to one another.

7. The heat exchanger as claimed in claim 3, characterized in that the longitudinal axes of the channels run parallel to the vertical.

8. The beat exchanger as claimed in claim 3, characterized in that the longitudinal axes of the channels run parallel to the horizontal.

9. The heat exchanger as claimed in claim 8, characterized in that at least some of the channels have a flow retarder or are closed.

10. The heat exchanger as claimed in claim 2, characterized in that the unit has along the vertical a length that is at least greater than half the height of the at least one heat exchanger block along the vertical, preferably greater than or equal to the height of the at least one heat exchanger block along the vertical.

11. The heat exchanger as claimed in claim 2, characterized in that the unit is arranged between the at least one heat exchanger block and a neighboring portion of the shell.

12. The heat exchanger as claimed in claim 1, characterized in that the heat exchanger has a further heat exchanger block, which is arranged in the shell space and along the horizontal is arranged next to the one heat exchanger block

13. The heat exchanger as claimed in claim 2, characterized in that the unit is arranged between the two heat exchanger blocks.

14. The beat exchanger as claimed in claim 2, characterized in that the heat exchanger has a plurality of units which respectively have a plurality of cylindrical channels for conducting the liquid phase of the first medium that run parallel to one another, in particular the respective unit being arranged between one of the heat exchanger blocks and a neighboring portion of the shell or between two heat exchanger blocks.

Description

[0039] In the figures:

[0040] FIG. 1 shows a schematic, partially sectional view of a heat exchanger according to the invention with a standing shell and vertical channels,

[0041] FIG. 2 shows a plan view in the form of a detail of the vertical channels shown in FIG. 1;

[0042] FIG. 3 shows a schematic, partially sectional view of a further heat exchanger according to the invention with a lying shell and vertical channels;

[0043] FIG. 4 shows a schematic, partially sectional view of a heat exchanger according to the invention with a standing shell and horizontal channels,

[0044] FIG. 5 shows a plan view in the form of a detail of the horizontal channels shown in FIG. 4;

[0045] FIG. 6 shows a schematic, partially sectional view of a further heat exchanger according to the invention with a lying shell and horizontal channels; and

[0046] FIG. 7 shows a schematic sectional view of two heat transfer passages of a plate heat exchanger such as can be used in the case of FIGS. 1, 3, 4 and 6.

[0047] FIG. 1 shows in conjunction with FIG. 2 a heat exchanger 1, which has a standing, preferably (circular) cylindrical shell 2, which delimits a shell space 3 of the heat exchanger 1. The shell 2 has in this case a peripheral, cylindrical walling 14, which is delimited at the end faces by two walls 15 lying opposite one another. The longitudinal axis or cylinder axis of the shell 2 coincides with the vertical z.

[0048] Arranged horizontally next to one another in the shell space 3 enclosed by the shell 2 there are in the present case two heat exchanger blocks 4, 5, which are plate heat exchangers 4, 5 that have a number of parallel heat transfer passages P. P (cf. FIG. 7).

[0049] The respective plate heat exchanger 4, 5 has in this case a plurality of heat directing structures 41, which may be sheets that are formed in cross section as meandering, that is to say for example corrugated, serrated or with a rectangular profile. These structures 41 are also referred to as fins 41 and are respectively arranged between two planar separating plates or sheets 40 of the plate heat exchanger 4, 5. In this way, between every two separating plates 40 (or a separating plate and a cover plate, see below) there are formed a multiplicity of parallel channels or there is formed a heat transfer passage P, P, through which the respective medium M1, M2 can flow. The two outermost layers 40 are formed by cover plates of the plate heat exchanger 4, 5; provided to the sides, between every two neighboring separating plates or separating and cover plates 40, there are terminal bars 42. FIG. 7 shows by way of example in the form of a detail a first heat transfer passage P for the first medium M1, which is formed by a fin 41 and two adjacent separating plates 40, and a neighboring second heat transfer passage P for the second medium M2, which is likewise formed by a fin 41 and two adjacent separating plates 40. Such an arrangement of passages is preferably repeated in the respective plate heat exchanger 4, 5, so that a number of first and second heat transfer passages P, P are arranged next to one another in an alternating manner.

[0050] During operation of the heat exchanger 1, the shell space 3 is filled with a first medium M1. This inlet stream into the heat exchanger 1 is usually two-phase, but may also be just liquid. The liquid phase F1 of the first medium Mi then forms a bath surrounding the plate heat exchangers 4, 5, the gaseous phase G1 of the first medium M1 collecting above the liquid phase F1 in an upper region of the shell space 3, from where it can be drawn off.

[0051] The liquid phase F1 of the first medium M1 rises up in the first heat transfer passages P of the plate heat exchangers 4, 5 and, as a result of indirect heat transfer, is thereby partially vaporized by the second medium M2 to be cooled, which is for example conducted in cross-flow in relation to the first medium M1 in the second heat transfer passages P of the plate heat exchangers 4, 5. The gaseous phase G1 of the first medium M1 thereby produced can leave at an upper end of the plate heat exchangers 4, 5 and is drawn off from the shell space 3 above the blocks 4, 5. Part of the liquid phase F1 continues to circulate in the shell space 3, the part referred to being transported from the bottom upward in the plate heat exchangers 4, 5 in the first heat transfer passages P and then flowing downward again outside the plate heat exchangers 4, 5 in the shell space 3.

[0052] The second medium M2 is directed into the plate heat exchangers 4, 5 and, after passing through the assigned second heat transfer passages P, is drawn off from the plate heat exchangers 4 5 in a cooled or liquefied state.

[0053] In order then to still the liquid phase F1 in the shell space 3 when there is a fluctuating movement of the shell 2, in which the longitudinal axis or cylinder axis fluctuates about the vertical z, according to FIG. 1 three units 100 are provided, each with a number of parallel channels 10, which respectively extend along a longitudinal axis L, which runs parallel to the longitudinal axis z of the shell 2. According to FIG. 2, these channels 10 are preferably formed by a plurality of hollow profiles 11, which are suitably connected to one another, delimit for example circular-cylindrical channels 10 and at the same time have at each of the end faces on both sides an opening 10a, 10b, the one opening 10a facing upward and being locatedalong the vertical zapproximately at the height of an upper end of the respective plate heat exchanger 4, 5 and the other, opposite opening 10b respectively facing downward and endingalong the vertical zbelow the blocks 4, 5. The channels 10 are preferably arranged next to one another along two orthogonal spatial directions.

[0054] The vertical channels 10 then allow the liquid phase F1 that is leaving the respective plate heat exchanger 4, 5 at the upper end from the first passages P to circulate again to the bottom, where the liquid phase F1 then enters the first heat transfer passages P at the lower end of the plate heat exchangers 4, 5 and, on account of the thermosiphon effect, is drawn upward again, is thereby partially vaporized and cools down the second medium M2.

[0055] The vertical channels 10 in this case represent a flow resistance in the horizontal direction and therefore suppress corresponding horizontal motions of the liquid phase F1 of the first medium M1, while the vertical circulation referred to through the channels 10 is protected.

[0056] According to FIG. 1, one of the units 100 between the two plate heat exchangers 4, 5 is arranged laterally in relation to the two blocks 4, 5. The two other units 100 are respectively arranged between a plate heat exchanger 4, 5 and a horizontally neighboring portion or inner side region 2a of the peripheral walling 14 of the shell 2.

[0057] FIG. 3 shows a modification of the heat exchanger 1 according to FIG. 1, which as a difference from FIG. 1 has a lying, longitudinally extended shell 2, which extends along a longitudinal axis or cylinder axis that coincides with the horizontal, that is to say runs perpendicularly in relation to the vertical z. As a. difference from FIG. 1, here two plate heat exchangers 4, 5 are arranged one behind the other along the longitudinal axis of the shell 2, the two blocks 4, 5 respectively being flanked laterally on both sides by a unit 100, which is designed in the way described above, the units 100 respectively flanking the two blocks 4, 5 over the entire combined length of the two blocks 4, 5 along the longitudinal axis of the shell 2.

[0058] FIG. 4 shows a further modification of the heat exchanger 1 according to FIG. 1, in which, as a difference from FIG. 1, the channels 10 run horizontally, that is to say perpendicularly in relation to the longitudinal axis of the standing shell 2, which coincides with the vertical z. The openings 10a, 10b of the channels 10 then respectively face in a horizontal direction. According to FIG. 1, the units 100 are arranged with respect to the plate heat exchangers 4, 5, the unit 100 between the two blocks 4, 5 having channels 10 with a greater flow cross-sectional area than the units 100 on the outer sides of the blocks 4, 5. Along the vertical z, all of the units 100 project beyond the upper and lower ends of the plate heat exchangers 4, 5, in order as far as possible to still the entire filling level of the liquid phase F1 of the first medium M1 when there is a fluctuating movement of the heat exchanger 1, in which the longitudinal axis z of the shell 2 according to FIG. 4 changes its inclination, in particular out of the plane of the page. The stilling is in this case produced by the flow resistance that the liquid phase F1 undergoes in the horizontal channels, for example when flowing back and forth between the openings 10a, 10b of the channels 10. According to FIG. 4, the channels 10 or units 100 may be formed with a plurality of cross-sectional rectangular or square hollow profiles or by plate-shaped elements, in particular sheets (see above), that are fitted one into the other or fastened to one another. According to FIG. 5, the vertical channels 10 may not only be rectangularly formed in cross section, as shown by way of example in FIG. 4, but also circularly. Other forms are likewise conceivable. To increase the flow resistance in the horizontal direction, individual horizontal channels 10 may be provided with an additional flow retarder (for example a cross-sectional constriction) 12 or be completely closed 12.

[0059] FIG. 6 finally shows a heat exchanger 1 in the manner of FIG. 4 with horizontal channels 10, the shell 2 of the heat exchanger now being formed according to FIG. 3 and arranged as lying. In this case, on both sides of the plate heat exchangers 4, 5 arranged one behind the other, which are placed according to FIG. 3, provided in each case between the respective block 4, 5 and a horizontally neighboring inner side region or portion of the peripheral walling 14 of the shell 2 there is a unit 100 with a number of horizontal channels 10 arranged one above the other and next to one another, which however have a smaller extent along the longitudinal axis of the shell 2 than the blocks 3, 4 along this direction. This allows the least possible disturbance of the vertical circulation of the liquid phase F1 (see above). According to FIG. 6, a further unit 100 is also arranged between the two blocks 4, 5 along the longitudinal axis of the shell 2. Here, too, the stilling of the liquid phase F1 of the first medium works in the way described on the basis of FIG. 4.

[0060] In principle, the interconnected (or else individual) hollow profiles 11 or channels 10 may be provided in different cross-sectional forms (for example circular, rectangular, honeycomb-shaped) and lengths at any position of the shell space 3 not occupied by the respective plate heat exchanger 4, 5, but mainly in the liquid-filled region (that is to say next to the block 4 or 5, the blocks 4, 5 and/or between the blocks 4, 5). The number of units or registers 100 is adaptable. These units 100 are only flowed through by the liquid phase F1 in the vertical direction or in the horizontal direction. The assembly itself represents a flow resistance in the horizontal direction. As a result, horizontal flows are damped. The units 100 or channels 10 can be adapted to the respective requirements both in vertical dimensions and in horizontal dimensions and may possibly also be subdivided. The size of the individual channels 10 in cross section is flexible and can likewise be adapted to the respective requirements. The individual channels 10 of the units 100 may have different lengths. In particular in the case of horizontal channels 10 or hollow profiles 11, individual profiles 11 may be closed, in order to adapt the flow resistance. As a result, horizontal flows are damped.

[0061] To sum up, the units or hollow-profile registers 100 according to the invention allow a great influence to be exerted on the flow direction of the circulating liquid F1 in the container 2, without a great number of individual parts being required for this. The liquid volume outside the plate heat exchangers 4, 5 can be segmented to a very great extent, though the production and assembly expenditure for this remains relatively low. The segmentation also allows small wall thicknesses of the units 100 or channels 10/hollow profiles 11, since the assembly 100 represents a robust body 100 and only allows small-scale liquid motions. Adapting the dimensions of the individual elements 10 and of the assembly 100 as a whole allows the natural frequencies of oscillating liquid F1 in the container 2 or shell space 3 to be influenced and motions to be damped. Consequently, natural frequency excitation and high oscillation amplitudes can be prevented.

[0062] Particularly preferably, the heat exchanger 1 according to the invention is used on a floating body on a body of water, for example as a component of a floating installation for producing liquefied natural gas (LNG).

TABLE-US-00001 List of designations 1 Heat exchanger 2 Shell 2a Inner side 3 Shell space 4, 5 Plate heat exchanger 10 Channel 10a, 10b Opening 11 Hollow profile 14 Walling 15 Wall 40 Separating plates 41 Heat-directing structures or fins 42 Side bars 100 Unit M1 First medium M2 Second medium G1 Gaseous phase of first medium F1 Liquid phase of first medium P First heat transfer passage P Second heat transfer passage Z Vertical