EP2511642A2 - Heat exchanger with additional liquid regulation in jacket area - Google Patents

Abstract

The heat exchanger (1) has a control unit (33) designed to regulate the distribution of a stream (S) of a fluid (F) in a jacket space (200) or to regulate another fluid stream (S') that is guided in the jacket space. A coiled tube bundle (10) is formed around a core tube (100) for a medium. A liquid distributor (40) is comprised of a main distributor (44) above the tube bundle for receiving the distribution of liquid stream, where the main distributor has through-openings, by which the liquid is passed through the tube bundle.

Description

The invention relates to a heat exchanger according to the preamble of claim 1.

Such a heat exchanger is used for indirect heat exchange between a first and a second medium and has at least one tube bundle for receiving the first medium, a sheath enclosing the at least one tube bundle, which defines a tube space surrounding the tube space for receiving the second medium in the form of a liquid , and a liquid distributor, which is designed to distribute a guided in the shell space flow (main stream) of the second medium over a cross section of the shell space. The tube bundle is preferably formed from a plurality of tubes that are wound around a core tube that extends along the longitudinal axis (cylinder axis) of the jacket in the shell space.

Such a heat exchanger is from the DE 10 2004 040 974 A1 known.

In heat exchangers with falling film evaporation, ie, the liquid to be evaporated flows from top to bottom through the evaporation space (shell space) and is partially evaporated, the heat transfer between shell side (shell space) and tube side (tube bundle) based on a uniform supply of heat from both sides. On the tube side, the currents are evenly distributed over all layers. Owing to external conditions, however, this uniform distribution can be impaired, eg by gas nitride in an otherwise purely liquid stream. On the shell side, the liquid distribution systems are designed so that a two-phase liquid / gas mixture (second medium) is calmed and degassed in a pre-distribution system. Subsequently, the degassed liquid is dammed up via a downpipe to generate pressure and fed to the actual main distribution system. The liquid is braked by a fixed flow brake in the lower part of the downpipe and further degassed. The main distribution system is load-independent and static, whereby changes in the overall system (eg gas content, load) can affect the quality of the distribution.

The present invention is based on the problem of improving a heat exchanger of the type mentioned in terms of said distribution quality.

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

Thereafter, a control means is provided, which is adapted to control the distribution of an additional in the mantle space parallel to the current (main flow) out further current (partial flow) of the liquid in the shell space and / or the distribution of the stream (main stream) of the liquid in the shell space Taxes.

According to the invention, in particular the shell side (and possibly the tube side, see below), the amount of heat offered is influenced in order to be able to react to the respective prevailing conditions. For this purpose, in particular on the shell side, the distribution and feeding of a part of the liquid (further stream) is conducted parallel to the said (main) stream. As a result, the liquid distribution can be adjusted specifically from the outside to the conditions present in the heat exchanger.

By the separate shell-side regulation of the partial flow or the further flow of the liquid, it is possible to counteract misalignments and / or discontinuities, which may be detected by temperature measurements, counteract targeted. Such maldistributions or discontinuities may be impressed from outside the heat exchanger or result from thermodynamic processes in the tube bundle of the heat exchanger. Due to the controlled shell-side liquid distribution, the heating surface of the heat exchanger can be used optimally and the output can be kept higher even in unfavorable conditions than without the aforementioned regulation.

For distributing the liquid to be distributed of said (main) stream, the liquid distributor on a main manifold above the tube bundle, which is provided with through holes (hole bottom) through which the liquid can rain down on the tube bundle.

Preferably, at least one additional, controllable with the control means line is provided with at least one arranged above the tube bundle outlet, via which the further flow of the liquid is controllably aufbar on the tube bundle. Here, the control means for controlling the distribution of the further flow of liquid to the tube bundle at least one valve of said conduit, with the e.g. the effective cross section of that line is variable.

Furthermore, the main distributor has at least one passage region through which tubes of the tube bundle run, wherein that passage region is delimited in particular by two distributor arms of the main distributor, via which the liquid can be applied to the tube bundle. By means of this passage region, the at least one line is preferably also led through in order to be able to predefinably distribute the further stream (partial stream) to the tube bundle arranged below the main distributor.

Of course, a plurality of lines, each with at least one outlet, can also be provided for guiding the further stream or further streams, via which liquid is additionally controllably settable on the tube bundle, the outlets preferably being oriented over the (perpendicular to the longitudinal axis of the shell) Cross-section of the jacket space are distributed, which is the other stream of fluid in a radial direction of the shell at least two (or more) sections of the tube bundle and / or variably distributed in a circumferential direction of the shell, so the distribution of the further flow to the sections can be regulated separately for each section.

For distributing the said stream (main stream) of the liquid, the main distributor preferably has a plurality of distributor arms which are each extended in particular in the radial direction of the jacket. In particular, the distributor arms each have a cake-pieced (circular sector-like) shape. The passage areas are then preferably shaped accordingly.

For feeding the main distributor with the flow (main flow) of the liquid to be distributed, the liquid distributor has at least one drop tube, which is preferably arranged in the core tube of the tube bundle and in particular has an outer diameter which is smaller than the inner diameter of the core tube. The main distributor is connected via the at least one downpipe with a pre-distributor of the liquid distributor, which serves to collect and calm the liquid.

In a variant of the invention, the distributor arms for the variable (controllable) distribution of the stream (main stream) of the liquid in the radial direction are subdivided into at least two separate (or more) segments, each having at least one through-opening, through which liquid rain on the tube bundle can, wherein the control means is arranged and provided to regulate a supply of liquid in the two (or more) segments for each segment separately, so that the liquid in the radial direction of the shell on at least two (or a plurality of) sections of the tube bundle is variably distributable. For this purpose, the individual segments can be associated with downpipes (eg with valves) via which the said segments can be controllably charged with liquid of the said stream (main stream), so that the distribution of the liquid to those two sections (or several sections) for each Section is separately controllable.

In a further embodiment it is provided that at least two (or more) distributor arms are designed to apply liquid to different sections of the tube bundle along the radial direction of the jacket. In this case, the said distributor arms for distributing the liquid of the stream (main stream) to the sections each have at least one passage opening through which liquid can be applied to the tube bundle, wherein those passage openings are positioned differently along the radial direction, so that selectively with the distributor arms Sections of the tube bundle with liquid (adjustable) can be acted upon. For supplying the distributor arms with the liquid to be distributed, a plurality of downpipes are preferably provided, with one downpipe each supplying at least one, in particular two distributor arms with liquid. Here, those downpipes are arranged in particular in the core tube or are formed by a division of the core tube into sections. By regulating the supply of liquid through those downpipes (eg by means of valves), the distribution of the said stream (main stream) of the liquid to the sections of the tube bundle for each section can also be regulated separately.

Also on the tube side, a control can be made, which cooperates with the shell-side regulation by the tubes of the tube bundle or tube space are wound around the core tube, that at least the above-mentioned first and second sections of the tube bundle are formed (or several sections). In this case, the sections are formed separately from each other and each encircle the core tube, wherein the second section surrounds the first section of the tube bundle, ie, the sections divide the tube bundle in the radial direction of the shell, the longitudinal axis or cylinder axis with the longitudinal axis (cylinder axis) of the Core tube coincides. There may be more than two sections, e.g. three sections, be present.

The first and second sections penetrate each other when the two hollow cylinders formed by the sections at least partially overlap one another. The radially innermost section extends in such a case up to a given radius R1 away from the core tube. The second section extends from a radius R2 to a radius R3 of the core tube. If the second section surrounds the first section, the radius R2 is at least as large as the radius R1. If the second section penetrates the first section, the radius R2 is smaller than R1. The two hollow cylinders, which are formed by the sections, thus overlap at least partially. In the context of the invention, the complete overlap of the two sections is possible.

Depending on the specific embodiment of the invention, 3 or more sections are advantageous, wherein the individual sections can surround or penetrate each other. Analogous to the preceding explanations, it is advantageous if a third section surrounds a second section, which in turn surrounds a first section. Likewise, it is advantageous in an alternative embodiment, when a third section penetrates a second section, which penetrates a first section. Combinations of surrounding sections with intersecting sections, as well as more than 3 sections, are alternative useful embodiments of the invention.

The separate (hollow cylindrical) sections furthermore each have at least one associated inlet, so that they can each be charged separately with the first medium. In this regard, a further control means may be provided, with in that the feed of the first medium via the respective inlet of a section is controllable separately from the feed of the first medium via the inlets of the other sections (eg by means of valves associated with the inlets). Furthermore, the individual sections each comprise at least one associated outlet for discharging the first medium from the tube space or jacket.

The regulation preferably takes place on the tube side and / or the jacket side as a function of the measurement of the temperature at one or more points of the heat exchanger. The heat exchanger expediently has at least optical waveguide which is connected to a suitable device for determining the temperature from the signals of the optical waveguide. The use of optical waveguides allows the determination of the temperature at any and at any number of points of the optical fiber via the evaluation of optical signals from the Raman scattering, the Brillioun scattering or the scattering at the Bragg grating. All these signals are temperature dependent and therefore suitable for temperature determination. The optical waveguides are advantageously mounted directly on the pipes or in the tubes of the heat exchanger.

Further features and advantages of the invention will be explained in the following description of exemplary embodiments with reference to the figures.

Fig. 1

eine ausschnitthafte, schematische Schnittansicht eines Wärmetauschers mit einem regelbaren Teilstrom einer zu verteilenden Flüssigkeit;

Fig. 2

eine schematische Draufsicht auf Verteilerarme eines Flüssigkeitsverteilers eines Wärmetauschers zum Regeln der Verteilung eines Hauptstromes einer zu verteilenden Flüssigkeit; und

Fig. 3

eine weitere schematische Schnittansicht eines Wärmetauschers mit einem Rohrbündel, das separat (regelbar) beaufschlagbare radiale Sektionen ausbildet;

Show it:

Fig. 1

a fragmentary, schematic sectional view of a heat exchanger with a controllable partial flow of a liquid to be distributed;

Fig. 2

a schematic plan view of distribution arms of a liquid distributor of a heat exchanger for controlling the distribution of a main flow of a liquid to be distributed; and

Fig. 3

a further schematic sectional view of a heat exchanger with a tube bundle, the separately (adjustable) acted upon radial sections forms;

FIG. 1 shows a heat exchanger 1, which has a, in particular hollow cylindrical, pressure-bearing jacket 20 (in the FIG. 1 not shown), whose longitudinal or cylindrical axis extends - relative to an intended arranged state of the heat exchanger 1 - along the vertical Z. The jacket 20 defines a jacket space 200, in which a wound tube bundle 10 is arranged. This has a plurality of tubes which are wound in several layers around a core tube 100, whose longitudinal axis coincides with the longitudinal axis of the shell 20. The tube bundle 10 is thus arranged coaxially with respect to the jacket 20.

In the tube space (tube bundle 10) at least a first medium is fed, which flows along the vertical Z upwards. The jacket space 200 serves to receive a second medium in the form of a liquid F, which is applied to the at least one tube bundle 10 and flows downwards in the jacket space along the vertical Z. Due to the formation of the tube bundle 10 as a wound tube bundle, the first medium is thus performed in cross-counterflow to the liquid F.

For distributing the liquid F in the shell space 200, a stream S of the liquid F introduced into the shell 20 is collected in a pre-distributor 43, calmed and degassed. The pre-distributor 43 has for receiving the liquid F while a circumferential wall, which extends from a transverse to the longitudinal axis of the shell 20 bottom. The bottom of the pre-distributor is connected to a main distributor 44 via a downpipe 380 extending in the core tube 100 in order to supply it with the stream S of the liquid F, that main distributor 44 for distributing the stream S of the liquid F over the entire cross section of the jacket space 200 transverse to the vertical Z has a plurality of distribution arms 300 (see. FIG. 2 ), each of which depart in a circular-sector-shaped manner in a radial direction R of the jacket 20 from the core tube 100, so that between the distributor arms 300 passage regions 45 are formed (see. FIG. 2 ), through which the tubes of the tube bundle 10 can be guided past the main distributor 44.

The distributor arms 300 each have a bottom with a plurality of through holes (so-called hole bottoms) through which liquid F introduced into the distributor arms 300 can rain on the tube bundle 10 arranged along the vertical Z below.

In order to be able to influence the distribution of the liquid F in the shell space and, if necessary, e.g. To be able to counteract an unequal distribution, the distribution and supply of a part of the liquid F in the form of at least one further stream S 'is now performed on the shell side parallel to the (main) stream S.

For this purpose, additional lines 330 are provided for conducting the further stream S '(or the further streams) which are guided via corresponding inlets / nozzles 332 into the shell space 200 and in each case have at least one outlet 331 via which the liquid F is additionally controllable the at least one tube bundle 10 can be abandoned. The lines 330 therefore each have a valve 333. In order to be able to give the liquid F controlled via the lines 330 to the tube bundle 10, the lines 330 are passed through the said passage areas 45 of the main manifold 44 and their outlets 331 arranged above the tube bundle 10, in particular in such a way that the tube bundle 10 in the radial direction R of the jacket 20 can be subjected to the liquid F separately in sections. The said sections of the shell in each case revolve around the core tube 100 and are hollow (circular) cylindrical in shape. The individual sections thus encompass each of the radially inner sections.

FIG. 2 shows ways to control the main flow S. Here, the circular sector shaped distribution arms 300 of a main distributor 44 in the manner of FIG. 1 , which are separated from each other by the said passage regions 45, for the variable distribution of the stream S of the liquid F in the radial direction R at least be divided into, for example, three separate segments 351, 352, 353, each having at least one through hole 370, through which the liquid F can rain down on the underlying tube bundle 10. If now a supply of liquid F in the said segments 351, 352, 353 for each of the segments 351, 352, 353 regulated separately, for example by each segment 351, 352, 353 is fed via a controllable by a valve drop tube (eg from a Pre-distributor 43), so For example, the flow S of the liquid F in the radial direction R of the jacket 20 can be variably distributed over a number of sections of the tube bundle corresponding to the number of segments (see above).

Alternatively, the dispenser arms 300 may be configured to apply liquid F to different sections of the tube bundle 10, eg, by appropriately distributing the through holes 371 of the dispenser arms 300 along the radial direction R, respectively FIG. 2 , To illustrate this, the distributor arms 300 are shown in FIG FIG. 2 depending on a through hole 371, which is shifted relative to the respective through holes 371 of the adjacent distribution arms 300 in the radial direction R. Other such distributions, in particular with multiple through holes per distribution arm 300 are also conceivable. In order to be able to feed the individual distributor arms 300 with liquid F of the (main) stream S, it is preferably provided that the core tube 100 is subdivided into sections 381-386, so that a corresponding number of downpipes is formed, which in each case preferably have a controllable design are (for example by means of valves) and each at least one associated distribution arm 300 with the liquid F feed (see. Fig. 2 ). It is also conceivable that a section 381-386 of the core tube 100 acts on more than one distributor arm 300, for example two distributor arms 300, with the liquid F. The said downpipes 381-386 in turn may, for example, from a pre-distributor 43 according to FIG. 1 be fed.

FIG. 3 also shows, with reference to a schematic sectional view of a heat exchanger 1, the additional possibility for the corresponding sectional division or control of the pipe flows. For this purpose, the tubes of the tube bundle 10 arranged coaxially with the jacket 20 of the heat exchanger 1 are preferably wound around the core tube 100 (not shown) such that a first, a second and a third hollow cylindrical section 11, 12, 13 of the tube bundle 10 are formed by way of example , which are formed separately from each other and respectively circulate the core tube 100, wherein the second section 12, the first section 11 of the tube bundle 10 and the third section 13, the two other sections 11, 12 surrounds. These sections 11, 12, 13 can now be irrigated separately controllable with the liquid F as described above. In addition, the three sections 11, 12, 13 can not only be charged separately via at least one associated inlet E, E ', E "at a lower end of the jacket 20 with the first medium, but the impingement of the tube side can Also, valves 301, 302, 303 associated with the inlet E, E ', E "of a further control means 30 can be regulated in addition to the shell-side control via at least one outlet A, A, A "per section from the tube bundle 10 are deducted.

LIST OF REFERENCE NUMBERS

1 heat exchangers 10 tube bundle 11 First section 12 Second section 13 Third section 20 coat 30 Other control means 33 control means 40 liquid distributor 43 preliminary distributor 44 main distribution 45 Passage area 100 core tube 200 shell space 300 distributor 301 Valve 302 Valve 303 Valve 330 management 331 outlet 332 inlet 333 Valve 351 segment 352 segment 353 segment 370 Through opening 371 Through opening 380 downspout 381-386 Section downpipe A, A ', A " outlet E, E ', E " inlet S electricity S ' Another stream R Radial direction Z vertical U circumferentially

Claims (15)

Heat exchanger for indirect heat exchange between at least a first and a second medium, comprising: a tube bundle (10) formed from a plurality of tubes wound around a core tube (100) for receiving the first medium, - A the tube bundle (10) enclosing jacket (20) defining a tube bundle (10) surrounding the jacket space (200) for receiving the second medium, and a liquid distributor (40) which is set up and provided to distribute a stream (S) of the second medium in the shell space (200) in the form of a liquid (F) in the shell space (200), characterized,
that a control means (33) is provided, which is set up and provided for to regulate the distribution of an additional stream (S ') of the liquid (F) in the jacket space (200) guided in the jacket space (200), and / or - To regulate the distribution of the flow (S) of the liquid (F) in the shell space (200). Heat exchanger according to claim 1, characterized in that the liquid distributor (40) has a main distributor (44) above the tube bundle (10) for receiving liquid (F) to be distributed of said stream (S), the main distributor (44) having passage openings, through which the liquid (F) can be applied to the tube bundle (10). Heat exchanger according to claim 1 or 2, characterized in that at least one additional line (300) is provided with at least one outlet, via which the further flow (S ') of the liquid (F) controllably on the tube bundle (10) is aufbar, wherein the control means (33) in particular for Rules of distribution of the further stream (S ') of the liquid (F) at least one valve (333) for the line (300). Heat exchanger according to claim 2 or claim 3 as far back referred to claim 2, characterized in that the main distributor (44) has at least one passage region (45) through which tubes of the tube bundle (10) are passed, said passage region (45) in particular by two distributor arms (300) of the main distributor (44) is delimited, via which the liquid (F) on the tube bundle (10) is aufbar. Heat exchanger according to claims 3 and 4, characterized in that the at least one line (330) is passed through the at least one passage region (45). Heat exchanger according to claim 3 or any one of claims 4 to 5 as far back referring to claim 3, characterized in that a plurality of lines (330) each having at least one outlet (331) are provided, via which the further stream (S ') of the Liquid (F) controllably on the tube bundle (10) is aufbar, wherein the outlets (331) are distributed over the cross section of the shell space (200), that the further flow (S ') of the liquid (F) in a radial direction ( R) of the jacket (20) is variably distributable at least to a first and a second section (11, 12, 13) of the tube bundle (10) and / or in a circumferential direction (U) of the jacket (20). Heat exchanger according to claim 2 or any one of claims 3 to 6 as far back referred to claim 2, characterized in that the main distributor (44) has a plurality of distributor arms (300), in particular in each case in the radial direction (R) of the jacket (20). are extended. Heat exchanger according to claim 7, characterized in that the distributor arms (300) for variably distributing the flow (S) of the liquid (F) in the radial direction (R) are subdivided into at least two separate segments (351, 352, 353), respectively have at least one passage opening (370), through which liquid (F) on the tube bundle (10) can be raised, wherein the control means (33) is arranged and provided, a supply of Liquid (F) in the two segments (351, 352, 353) separately to regulate, so that the liquid (F) in the radial direction (R) of the jacket (20) on at least a first and a second section (11, 12, 13) of the tube bundle (10) is correspondingly variably distributable. Heat exchanger according to claim 7, characterized in that at least one distributor arm (300) is arranged and provided along the radial direction (R) of the shell (20) a first section (11) and at least one other distribution arm (300) adapted thereto and is provided, along the radial direction (R) of the shell (20) a different second section (12) of the tube bundle with liquid (F) to act on, in particular the two distributor arms (300) for distributing the liquid (F) on the both sections (11, 12) each have at least one passage opening (371) through which liquid (F) can be applied to the tube bundle (10), wherein those passage openings (371) are positioned differently along the radial direction (R), and wherein in particular for feeding the distributor arms (300) with the liquid (F) a plurality of downpipes (381-386) is provided, wherein a downpipe (381-386) each at least one, in particular zw In particular, the downpipes (381-386) are arranged in the core tube (100) or are formed by a subdivision of the core tube (100) into sections (381-386). Heat exchanger according to one of claims 6, 8 or 9, characterized in that the tubes of the tube bundle (10) are wound around the core tube (100), that at least the first and the second section (11, 12, 13) of the tube bundle ( 10) is formed, wherein the two sections (11, 12, 13) are formed separately from each other and in each case the core tube (100) circulate, wherein the second section (12) surrounds the first section (11) of the tube bundle (10), and wherein the two sections (11, 12) each have at least one associated inlet (E, E '), so that the two sections (11, 12) can be loaded separately with the first medium. Heat exchanger according to claim 11, characterized in that a further control means (30) is provided, with which the feeding of the first medium in the first section (11) of the tube bundle (10) via the inlet (E) of the first Section (11) separately from the feed of the first medium in the second section (12) of the tube bundle (10) via the inlet (E ') of the second section (12) is adjustable. Heat exchanger according to claim 12, characterized in that the further control means (30) at least one valve (301) for the inlet (E) of the first section (11) and a valve (332) for the inlet (E ') of the second section ( 12). Heat exchanger according to one of claims 11 to 13, characterized in that the two sections (11, 12) each have at least one associated outlet (A, A ') for discharging the first medium. Heat exchanger according to one of claims 11 to 14, characterized in that the tubes are wound around the core tube (100), that a further third circumferential section (13) of the tube bundle (10) is formed, which surrounds the second section (12) wherein the third section (13) has at least one associated inlet (E "), so that the third section (13) can be fed with the first medium separately from the two other sections (11, 12), and wherein in particular the control means ( 30) is arranged and provided for feeding the first medium into the third section (13) of the tube bundle (10) via the inlet (E ") of the third section (13) separately from the feed of the first medium via the other inlets (13). E, E '), and wherein in particular the control means (30) comprises at least one valve (303) for the inlet (E ") of the third section (13), and wherein the third section (13) has at least one associated outlet (E A ") to omit the first Mediu ms from the third section (13) of the tube bundle (10). Heat exchanger according to one of the preceding claims, characterized in that the heat exchanger has at least optical waveguide which is connected to a suitable device for determining the temperature of the signals of the optical waveguide.

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