EP1178278B1 - Heat exchange tube with twisted inner fins - Google Patents

Heat exchange tube with twisted inner fins Download PDF

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Publication number
EP1178278B1
EP1178278B1 EP01117802A EP01117802A EP1178278B1 EP 1178278 B1 EP1178278 B1 EP 1178278B1 EP 01117802 A EP01117802 A EP 01117802A EP 01117802 A EP01117802 A EP 01117802A EP 1178278 B1 EP1178278 B1 EP 1178278B1
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EP
European Patent Office
Prior art keywords
pipe
ribs
symmetry
longitudinal axis
cross
Prior art date
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Expired - Lifetime
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EP01117802A
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German (de)
French (fr)
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EP1178278A2 (en
EP1178278A3 (en
Inventor
Jovan Prof. Dr.-Ing. Mitrovic
Steffen Dipl.-Kfm. Dittmann
Michael SCHÖNHERR
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Fw Brokelmann Aluminiumwerk & Cokg GmbH
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Fw Brokelmann Aluminiumwerk & Cokg GmbH
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
    • F28F13/06—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by affecting the pattern of flow of the heat-exchange media
    • F28F13/12—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by affecting the pattern of flow of the heat-exchange media by creating turbulence, e.g. by stirring, by increasing the force of circulation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F2255/00—Heat exchanger elements made of materials having special features or resulting from particular manufacturing processes
    • F28F2255/16—Heat exchanger elements made of materials having special features or resulting from particular manufacturing processes extruded
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S165/00—Heat exchange
    • Y10S165/51—Heat exchange having heat exchange surface treatment, adjunct or enhancement
    • Y10S165/518—Conduit with discrete fin structure
    • Y10S165/524—Longitudinally extending

Definitions

  • the invention relates to a tube with twisted inner ribs, the to the symmetry longitudinal axis of the tube rotationally symmetrical run.
  • a known tube of this type according to DE-GM 74 22 107 has on its inside several multi-course helical Inner ribs on which a small width b and a small radial Have extension e.
  • EP 0 582 835 A1 discloses a heat exchanger become known, consisting of several, in their outer wall graded, non-generic pipes composed in whose Interior further differently configured tubes with different dimensions and internal ribs concentric are arranged, which are to serve as oil cooler.
  • These Heat transfer tubes are in addition to their complex production Afflicted with the disadvantage of a significant pressure loss, because also - as far as it is present - a the Heat transfer increasing crossflow either not or can only happen accidentally and on the inner tube remains limited.
  • Heat transfer tube of the type mentioned above create, which is compared to the previously known internally ribbed pipes by a significantly better Heat transfer performance excels and for this purpose not only an increase in the internal heat transfer surface operated, but also an effective cross flow between the Inner wall surface of the tube and the core flow near the SymmetrielShsachse for heat transfer increase guaranteed.
  • each rib forms the Cross-sectional shape of each rib a pointed, isosceles Triangle with straight leg sides, whose Triangle point by means of a radius rounded off in the two Leg sides merges, each with two adjacent inner ribs form a trapezoidal cross-section space.
  • cross-sectional shape is basically from DE 33 34 964 A1 known, but there run the ribs without any twist, so that in conjunction with the twisting features of claim 1 not to be known as known.
  • each inner fin of the tube the shape of a Tooth on gears with convex outward flanks with rounded tooth tip, with two adjacent ribs a cross-sectionally U-shaped intermediate space with concave encompass sunken side surfaces.
  • This rib shape is especially suitable for high viscosity fluids such as oils.
  • each inner rib an isosceles, pointed triangle with concave inward-falling thorns and a semicircular shape at the top, with two adjacent each Internal ribs a trapezoidal space in cross section Embrace U-shaped, whose trapezoidal leg convexly outwards are arched.
  • This rib shape is preferably used in the Flow through fluids of low viscosity, as they for example, have gases.
  • these tubes are mass-produced with their Internal ribs made of extruded aluminum or copper or out made of extruded plastic. It is characterized both Aluminum as well as copper due to a high thermal conductivity.
  • the wall thickness of the pipe is determined by the System pressure determined and is advantageous in a range between 0.4 mm and 3 mm, each tube having at least four internal ribs having.
  • the distance a is the free ends of the inner ribs of the symmetry axis of the Pipe in fluids of high viscosity, such as oils, larger and at Low viscosity fluids, such as water and gases, lower sized. This increases the cross section of the Core flow in the area of the free cross section near the Symmetry longitudinal axis against high viscosity fluids Low viscosity fluids.
  • Fig. 1 is a first embodiment of the inventive tube 1 shown. This forms the Cross-sectional shape of each rib 2 a pointed, isosceles Triangle with straight leg sides 2a, 2b, whose Triangle tip 2c rounded by a radius r in the two Leg sides 2a, 2b passes. Two adjacent each Inner ribs 2 form a trapezoidal in cross-section Gap 2d.
  • each inner rib 3 of the tube 1, the shape of a tooth in gears with convex outside curved side flanks 3a, 3b with a rounded Tooth tip 3c on.
  • Two adjacent ribs 3 surround one in cross-section U-shaped space 3d with convex sunken side surfaces that are identical to the shape of the Side edges 3a, 3b of the ribs 3 are.
  • each inner rib 4 forms a isosceles, pointed triangle with concave inward incident leg sides 4a, 4b with a semicircular Tip 4c.
  • each case surround two adjacent inner ribs 4 U-shaped a cross-section trapezoidal space 4d, whose trapezoidal legs are curved convexly outward and identical to the leg sides 4a, 4b.
  • Each tube 1 is provided with at least four inner ribs 2, 3, 4, in present case, each with eight inner ribs 2, 3, 4 provided.
  • the Free ends 2c, 3c, 4c are with the tips of the cross-sectional shapes the individual inner ribs 2, 3, 4 identical. It must, however be noted that the tips are on the flat Cross-sectional body of a triangle, whereas the free ends are on a twisted to the symmetry longitudinal axis 5 extending refer to spatial body.
  • These free ends 2c, 3c, 4c have to the symmetry longitudinal axis 5 of the tube 1 a distance a, in the Ratio to the pipe inside diameter d in a range of 1: 12 to 1: 3 is.
  • the tubes are advantageous either from an extruded Aluminum or copper produced or extruded in plastic.
  • the wall thickness d 1 of the tube 1 is dependent on the system pressure and is in a range between 0.4 mm and 3 mm.
  • tubes 1 also other than those in Figures 1 to 3 shown tubes may consist, that is for example, only four, instead of the eight ribs 2, 3, 4 shown there Ribs 2, 3, 4 or more than eight ribs in the interior of the tube. 1 are arranged. Because the number of ribs 2, 3, 4, the length L of Twisting as well as the thickness and rib shape are dependent on the type of fluid and its flow velocity as well designed by the pressure drop. The general flow rule applies, that the smaller the free pressure, the greater the pressure drop Flow cross section in the core area and between the Single ribs 2, 3, 4, but that on the other hand with larger Number of ribs and larger size associated with it Heat transfer surface and the heat transfer performance passive rises.
  • Such a tube 1 is used, for example a shell and tube heat exchanger 12, as shown in Fig. 6.
  • a tube 1 enters the cooling medium through the pipe 13 in the tubes 1 and exits through the outlet 14.
  • Im Countercurrent occurs, for example, to be cooled medium through the Inlet 15 to the outside 11 of the tubes 1 and leaves the heat exchanger 12 in the cooled state by the Outlet 16.
  • the inventive Tube 1 both for cooling and for heating fluids Can be used, depending on the direction of the Heat transfer process to take place.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Geometry (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Rigid Pipes And Flexible Pipes (AREA)

Abstract

The heat transfer pipe (1), with a number of internal spiral ribs (2) in a symmetrical twist around the longitudinal axis (5), has a gap between the free ends (2c) of the ribs and the axis. The ratio of the gap to the inner diameter of the pipe is 1:12 to 1:3. The spiral ribs all have a twist in the same direction (6) and have the same twist length (L). The ribs have the shape of an equilateral triangle or a tooth. The pipe is of metal or plastics.

Description

Die Erfindung betrifft ein Rohr mit gedrallten Innenrippen, die zur Symmetrielängsachse des Rohres rotationssymmetrisch verlaufen.The invention relates to a tube with twisted inner ribs, the to the symmetry longitudinal axis of the tube rotationally symmetrical run.

Bei einem bekannten Rohr dieser Art gemäß der US-A-5,655,599 weisen die freien Enden der Innenrippen zur Symmetrielängsachse des Rohres einen Abstand a auf, der im Verhältnis zum Rohrinnendurchmesser d in einen Bereich von 1 : 5 bis 1 : 2,22 liegt. Ferner verlaufen bei den Ausführungsformen der Figuren 5, 6 und 8 sämtliche Innenrippen bis auf einen ungedrallten und daher gerade verlaufenden Anfangsbereich zur Symmetrielängsachse drallartig in gleicher Richtung, jedoch mit unterschiedlicher Drallänge (siehe Nebenansprüche 1 und 4 dieser Druckschrift). Bei einer weiteren Ausführungsform gemäß Figur 7 sind die Rippen mit entgegengesetzten Drallrichtungen versetzt. Die Rippen sind stets mit ihrer Spitze radial auf die Symmetrielängsachse des Rohres gerichtet und schließen einen Zwischenraum ein, der eine effektive quer zur Längsachse des Rohres verlaufende Querströmung nicht zuläßt.In a known tube of this type according to US-A-5,655,599 the free ends of the inner ribs to the symmetry longitudinal axis of the tube a distance a, in relation to the pipe inner diameter d within a range of 1: 5 to 1: 2.22. Furthermore, run at the Embodiments of Figures 5, 6 and 8 all inner ribs to on an ungraded and therefore straight starting area to the symmetry longitudinal axis like a spiral in the same direction, but with different twist length (see dependent claims 1 and 4 of this Volume). In a further embodiment according to FIG. 7 the ribs offset in opposite directions of twist. Ribs are always with their tip radially on the symmetry axis of the Directed pipe and include a gap, the one effective transverse flow transverse to the longitudinal axis of the tube does not allow.

Ein bekanntes Rohr dieser Art gemäß dem DE-GM 74 22 107 weist an seiner Innenseite mehrere mehrgängige schraubenartige Innenrippen auf, die eine geringe Breite b sowie eine geringe radiale Erstreckung e aufweisen. Dabei soll die Breite b in einem Bereich von 0,02 und 0,15 inch und die Höhe e in einem Bereich zwischen 0,0125 und 0,075 inch liegen; d.h. das Größtmaß in beiden Bereichen beträgt unter der Annahme 1 inch = 25,4 mm bei der Breite b = 3,8 mm, bei der Höhe e = 1,9 mm, bei einem Innendurchmesser von ca. 20,3 mm. Daraus folgt, daß sich in einem solchen von einem Fluid durchströmten Rohr zwar aufgrund des Verhältnisses von Rohrinnendurchmesser zu den relativ kurzen und im Querschnitt noppenartig ausgebildeten Innenrippen in der Nähe der Innenwand den Wärmeübergang fördernde Turbulenzen ausbilden, es jedoch an einer zur Hauptströmrichtung querverlaufenden Sekundärströmung fehlt und somit letztlich der Wärmeübergangseffekt auf die Strömungsverhältnisse der Hauptströmung und auf die durch die Wandunebenheiten ausgelösten Turbulenzen beschränkt bleibt.A known tube of this type according to DE-GM 74 22 107 has on its inside several multi-course helical Inner ribs on which a small width b and a small radial Have extension e. The width b should be in a range of 0.02 and 0.15 inches and the height e in a range between 0.0125 and 0.075 inches; i.e. the largest measure in both areas is assumed to be 1 inch = 25.4 mm at the Width b = 3.8 mm, at height e = 1.9 mm, at one Inner diameter of approx. 20.3 mm. It follows that in a Such through-flow of a fluid pipe due to the Ratio of pipe inside diameter to the relatively short and in cross-section knob-like inner ribs in the vicinity the inner wall, the heat transfer promoting turbulence form, but at one to the main flow direction transverse secondary flow is missing and thus ultimately the Heat transfer effect on the flow conditions of Mainstream and on through the wall bumps triggered turbulence remains limited.

Diesen Nachteil einer zu gringen Wärmeübertragungsfläche der Innenrippen hat offenkundig der Erfinder der gattungsfremden DE 196 09 641 C2 erkannt und zu diesem Zweck ein Rohr für die Kühlung von Betondecken mit Luft vorgeschlagen, welches mit erheblich längeren geraden Innenrippen versehen ist, die sich radial von der Innenwandung des Rohres in Richtung auf die Symmetrielängsachse erstrecken. Dieses Rohr ist jedoch mit dem Nachteil behaftet, daß die Kernströmung, d.h. die Strömung durch den freien, zentralen Raum in der Nähe der Symmetrielängsachse mit erheblichen Druckverlusten behaftet ist und eine effektive Wärmeübertragung zwischen dieser Kernströmung und der Rohrinnenwand dem Zufall überlassen bleibt, weil eine die Wärmeübertragung erhöhende Strömung quer zur Hauptströmung nicht vorhanden ist. Die Strömung innerhalb einer jeden von zwei benachbarten Rippenflanken und der Rohrinnenwand gebildeten Teilkammer ist aufgrund der Wandreibung mit einer geringeren Geschwindigkeit als die Kernströmung behaftet. Zudem ist der stoffliche Austausch zwischen der Kernströmung und der Strömung in den einzelnen Kammern dem Zufall überlassen. Da diese Rippen infolge der herabgesetzten Strömungsgeschwindigkeit in den Kammern den Wärmeübertragungskoeffizienten herabsetzen, beruht ihre positive Wirkung ausschließlich auf einer Vergrößerung der Wärmeübertragungsfläche. Das gleiche gilt für das gattungsfremde Rohr gemäß Fig. 2 der DE 27 03 341 C2.This disadvantage of a gripping heat transfer surface of Internal ribs obviously has the inventor of the stranger DE 196 09 641 C2 recognized and for this purpose a pipe for the Cooling concrete ceilings proposed with air, which with is provided significantly longer straight inner ribs, which are radially from the inner wall of the pipe towards the Symmetrielängsachse extend. This tube is however with the Disadvantage that the core flow, i. the flow through the free, central space near the symmetry longitudinal axis with significant pressure losses and an effective Heat transfer between this core flow and the Pipe inner wall left to chance, because a the Heat transfer increasing flow across the main flow not available. The flow within each of two formed adjacent rib edges and the pipe inner wall Partial chamber is due to the wall friction with a lower Speed as the core flow tainted. In addition, the Substantial exchange between the core flow and the flow in the individual chambers left to chance. Because these ribs due to the reduced flow rate in the Chambers reduce the heat transfer coefficient is based their positive effect exclusively on an enlargement of the Heat transfer area. The same applies to the non-generic Pipe according to FIG. 2 of DE 27 03 341 C2.

Weiterhin ist aus der EP 0 582 835 A1 ein Wärmeübertrager bekannt geworden, der sich aus mehreren, in ihrer Außenwandung abgestuften, gattungsfremden Rohren zusammensetzt, in deren Innenraum weitere unterschiedlich konfigurierte Rohre mit unterschiedlichen Abmessungen und Innenrippen konzentrisch angeordnet sind, die als Ölkühler dienen sollen. Diese Wärmeübertragungsrohre sind neben ihrer aufwendigen Herstellung mit dem Nachteil eines erheblichen Druckverlustes behaftet, weil auch dabei - soweit sie überhaupt vorhanden ist - eine die Wärmeübertragung erhöhende Querströmung entweder nicht oder nur zufällig entstehen kann und auf das innenliegende Rohr beschränkt bleibt.Furthermore, EP 0 582 835 A1 discloses a heat exchanger become known, consisting of several, in their outer wall graded, non-generic pipes composed in whose Interior further differently configured tubes with different dimensions and internal ribs concentric are arranged, which are to serve as oil cooler. These Heat transfer tubes are in addition to their complex production Afflicted with the disadvantage of a significant pressure loss, because also - as far as it is present - a the Heat transfer increasing crossflow either not or can only happen accidentally and on the inner tube remains limited.

Außer den vorgenannten Veröffentlichungen gibt es noch einen umfangreichen Stand der Technik mit innenberippten Rohren, wie z.B. aus der DE-OS 24 02 942, der DE-33 34 964 A1 und der DE-OS 26 15 168, die aber allesamt Innenrippen mit den oben dargelegten Nachteilen aufweisen. Da bei diesen eine Verdrallung fehlt, entsprechen sie nicht der Gattung der in der vorliegenden Erfindung beschriebenen Rohre.In addition to the aforementioned publications, there is one more extensive state of the art with internally tapped pipes, such as e.g. from DE-OS 24 02 942, DE-33 34 964 A1 and the DE-OS 26 15 168, but all internal ribs with the above have shown disadvantages. Because with these a twist lacking, they do not correspond to the genus of the present Invention described tubes.

Denn der Erfindung liegt die Aufgabe zugrunde, ein Wärmeübertragungsrohr der eingangs genannten Gattung zu schaffen, welches sich gegenüber den bislang bekannten innenverrippten Rohren durch eine erheblich bessere Wärmeübertragungsleistung auszeichnet und sich zu diesem Zweck nicht nur einer Erhöhung der inneren Wärmeübertragungsfläche bedient, sondern auch eine effektive Querströmung zwischen der Innenwandfläche des Rohres und der Kernströmung in der Nähe der Symmetrielängsachse zur Wärmeübertragungserhöhung gewährleistet.For the invention is based on the object Heat transfer tube of the type mentioned above create, which is compared to the previously known internally ribbed pipes by a significantly better Heat transfer performance excels and for this purpose not only an increase in the internal heat transfer surface operated, but also an effective cross flow between the Inner wall surface of the tube and the core flow near the Symmetrielängsachse for heat transfer increase guaranteed.

Diese Aufgabe wird in drei unterschiedlichen Ausführungsformen durch die Merkmale der Ansprüche 1, 2 und 3 gelöst. This task will be in three different embodiments solved by the features of claims 1, 2 and 3.

Durch diese Merkmale wird erstmalig ein Rohr geschaffen, welches aufgrund des geringen Abstandes a zwischen 1/12 und 1/3 des Innendurchmessers des Rohres nicht nur eine große Wärmeübertragungsfläche auf seiner Innenseite aufweist, sondern sich aufgrund der Drallung der Innenrippen in jedem gedrallten Zwischenraum zwischen zwei benachbarten Rippenflanken und der Rohrwandung einerseits und der durch den freien Raum in der Nähe der Symmetrielängsachse strömenden Kernströmung andererseits eine Querströmung mit relativ geringen Druckverlusten ausbildet, die für eine erhebliche Steigerung der Wärmeübertragungsleistung zwischen der Kernströmung und der Rohrwand sorgt. Dieses Wirkungsprinzip ist im gesamten Stand der Technik ohne Vorbild, sei es, daß nach dem nächstkommenden Stand der Technik gemäß der US-A-5,655,599 und dem DE-GM 74 22 107 sich aufgrund der kurzen noppenartigen Rippen keine ausgeprägte Querströmung, sondern nur eine erhöhte Turbulenz im Wandbereich ausbilden kann oder sei es, daß die längeren Rippen gemäß dem Stand der Technik keine Verdrallung aufweisen.These features create a pipe for the first time which due to the small distance a between 1/12 and 1/3 the inside diameter of the pipe is not just a big one Heat transfer surface has on its inside, but itself due to the spin of the inner ribs in each twisted Gap between two adjacent rib edges and the Pipe wall on the one hand and by the free space in the vicinity the symmetry longitudinal axis flowing core flow on the other forms a cross-flow with relatively low pressure losses, the for a significant increase in heat transfer performance between the core flow and the pipe wall. This Principle of action is in the entire state of the art without a model, let it is that of the closest prior art according to US-A-5,655,599 and the DE-GM 74 22 107 due to the short knob-like ribs no pronounced cross-flow, but only an increased Turbulence can form in the wall area or is it that the longer ribs according to the prior art no twisting exhibit.

Bei der Ausbildung der Querschnittsform der Innenrippen gestattet die Erfindung mehrere Ausführungsformen:In the formation of the cross-sectional shape of the inner ribs the invention allows several embodiments:

Bei der ersten Ausführungsform bildet die Querschnittsform einer jeden Rippe ein spitzes, gleichschenkeliges Dreieck mit gerade verlaufenden Schenkelseiten, dessen Dreieckspitze mittels eines Radius abgerundet in die beiden Schenkelseiten übergeht, wobei jeweils zwei benachbarte Innenrippen einen im Querschnitt trapezförmigen Zwischenraum bilden. Diese Querschnittsform ist zwar grundsätzlich aus der DE 33 34 964 A1 bekannt, jedoch verlaufen dort die Rippen ohne jeden Drall, so daß sie in Verbindung mit den Verdrallungsmerkmalen des Anspruchs 1 nicht als bekannt zu bezeichnen sind.In the first embodiment forms the Cross-sectional shape of each rib a pointed, isosceles Triangle with straight leg sides, whose Triangle point by means of a radius rounded off in the two Leg sides merges, each with two adjacent inner ribs form a trapezoidal cross-section space. These Although cross-sectional shape is basically from DE 33 34 964 A1 known, but there run the ribs without any twist, so that in conjunction with the twisting features of claim 1 not to be known as known.

Bei der zweiten Ausführungsform weist die Querschnittsform einer jeden Innenrippe des Rohres die Form eines Zahnes bei Zahnrädern mit konvex nach außen gewölbten Flanken mit abgerundeter Zahnspitze auf, wobei zwei benachbarte Rippen einen im Querschnitt U-förmigen Zwischenraum mit konkav eingefallenen Seitenflächen umgreifen. Diese Rippenform ist besonders für Fluide großer Viskosität wie Öle geeignet.In the second embodiment, the Cross-sectional shape of each inner fin of the tube the shape of a Tooth on gears with convex outward flanks with rounded tooth tip, with two adjacent ribs a cross-sectionally U-shaped intermediate space with concave encompass sunken side surfaces. This rib shape is especially suitable for high viscosity fluids such as oils.

Bei der dritten Ausführungsform weist die Querschnittsform einer jeden Innenrippe ein gleichschenkeliges, spitzes Dreieck mit konkav nach innen einfallenden Schenkeln und eine Halbkreisform an der Spitze auf, wobei jeweils zwei benachbarte Innenrippen einen im Querschnitt trapezförmigen Zwischenraum U-förmig umgreifen, dessen Trapezschenkel konvex nach außen gewölbt sind. Diese Rippenform findet bevorzugt Einsatz bei der Durchströmung von Fluiden geringer Viskosität, wie sie beispielsweise Gase aufweisen.In the third embodiment, the Cross-sectional shape of each inner rib an isosceles, pointed triangle with concave inward-falling thorns and a semicircular shape at the top, with two adjacent each Internal ribs a trapezoidal space in cross section Embrace U-shaped, whose trapezoidal leg convexly outwards are arched. This rib shape is preferably used in the Flow through fluids of low viscosity, as they for example, have gases.

Sämtliche dieser unterschiedlichen Ausführungsformen der Innenrippen führen zu unterschiedlichen Strömungen quer zur Kernströmung im Bereich der Symmetrielängsachse. Dabei wird vorteilhaft die Anzahl der Rippen, die Steigung der Verdrallung, die Rippendicke und die Form in Abhängigkeit von der Art des Fluids und dessen Strömungsgeschwindigkeit sowie vom Druckabfall gestaltet, ohne dadurch den Erfindungsgedanken zu verlassen.All of these different embodiments of the Inner ribs lead to different flows across Core flow in the area of the symmetry longitudinal axis. It will Advantageously, the number of ribs, the slope of the twist, the Rib thickness and shape depending on the type of fluid and its flow rate as well as the pressure drop designed, without thereby departing from the inventive concept.

Nach einer besonders vorteilhaften Weiterbildung der Erfindung werden diese Rohre in Massenfertigung mit ihren Innenrippen aus stranggepreßtem Aluminium oder Kupfer bzw. aus extrudiertem Kunststoff hergestellt. Dabei zeichnen sich sowohl Aluminium als auch Kupfer durch eine hohe Wärmeleitfähigkeit aus.After a particularly advantageous development of Invention, these tubes are mass-produced with their Internal ribs made of extruded aluminum or copper or out made of extruded plastic. It is characterized both Aluminum as well as copper due to a high thermal conductivity.

Zur Sicherstellung einer gleichmäßigen Kern- und Querströmung ist die Querschnittsgestaltung des Rohres mit seinen Innenrippen und den Zwischenräumen über die gesamte Länge der Verdrallung in jeder Querschnittsebene gleich.To ensure a uniform core and Cross-flow is the cross-sectional design of the pipe with its Inner ribs and the gaps over the entire length of the Verdrallung in each cross-sectional plane the same.

Die Wanddicke des Rohres wird in Abhängigkeit vom Systemdruck ermittelt und liegt vorteilhaft in einem Bereich zwischen 0,4 mm und 3 mm, wobei jedes Rohr mindestens vier Innenrippen aufweist.The wall thickness of the pipe is determined by the System pressure determined and is advantageous in a range between 0.4 mm and 3 mm, each tube having at least four internal ribs having.

Um eine möglichst hohe Wärmeübertragungsleistung bei einem relativ geringen Druckverlust zu erhalten, wird der Abstand a der freien Enden der Innenrippen von der Symmetrielängsachse des Rohres bei Fluiden großer Viskosität, wie bei Ölen, größer und bei Fluiden mit geringer Viskosität, wie Wasser und Gasen, geringer bemessen. Dadurch vergrößert sich der Querschnitt der Kernströmung im Bereich des freien Querschnittes in der Nähe der Symmetrielängsachse bei Fluiden großer Viskosität gegenüber Fluiden geringer Viskosität. To the highest possible heat transfer performance at a To obtain relatively low pressure drop, the distance a is the free ends of the inner ribs of the symmetry axis of the Pipe in fluids of high viscosity, such as oils, larger and at Low viscosity fluids, such as water and gases, lower sized. This increases the cross section of the Core flow in the area of the free cross section near the Symmetry longitudinal axis against high viscosity fluids Low viscosity fluids.

Erfindungsgemäß darf der freie Innenraum in der Nähe der Symmetrielängsachse in jedem Rohr auf keinen Fall geschlossen werden. Dieser Raum muß mit den Kanälen zwischen den Rippen kommunizieren. Aus diesem Grunde weisen in einer vorteilhaften Weiterbildung die freien Enden der Innenrippen von der Symmetrielängsachse auch bei Fluiden geringer Viskosität stets einen solchen Abstand a von dieser auf, daß zwischen dessen freien Enden in jedem Querschnitt des Rohres ein Kernströmkanal erhalten bleibt. Aus diesem Grund soll gemäß dem Merkmal a) des Hauptanspruchs dieser Abstand a nicht unter 1/12 des Rohrinnendurchmessers bemessen werden.According to the free interior space near the Symmetrielängsachse in each tube closed under any circumstances become. This space must match the channels between the ribs communicate. For this reason, in an advantageous Continuing the free ends of the inner ribs of the Symmetrielängsachse always with fluids of low viscosity such a distance a from this on, that between its free Ends in each cross section of the tube receive a core flow channel remains. For this reason, according to the feature a) of Main claim this distance a not less than 1/12 of Inside diameter of the pipe.

Mehrere Ausführungsbeispiele der Erfindung sind in den Zeichnungen dargestellt. Dabei zeigen:

  • Fig. 1 den Querschnitt eines Rohres mit acht Innenrippen, welche die Querschnittsform eines spitzen gleichschenkeligen Dreiecks aufweisen,
  • Fig. 2 eine weitere Querschnittsausbildung eines Rohres mit Innenrippen, von denen eine jede die Querschnittsform eines Zahnes bei Zahnrädern mit konvex nach außen gewölbten Flanken aufweist,
  • Fig. 3 eine dritte Querschnittsform eines Rohres, bei dem eine jede Innenrippe die Querschnittsform eines gleichschenkeligen, spitzen Dreiecks mit konkav nach innen einfallenden Schenkelseiten besitzt,
  • Fig. 4 eine perspektivische Ansicht des Rohres von Fig. 1 mit gestrichelt angedeuteter Verdrallung der Innenrippen,
  • Fig. 5 das Rohr von Fig. 4 in teilweise aufgeschnittener Perspektivansicht mit durch Pfeile angedeuteten Strömungen und
  • Fig. 6 eine beispielhafte Prinzipdarstellung eines Wärmeübertragers zum Einsatz der Rohre gemäß den Figuren 1 bis 5.
    • Several embodiments of the invention are illustrated in the drawings. Showing:
  • 1 shows the cross section of a tube with eight inner ribs, which have the cross-sectional shape of a sharp isosceles triangle,
  • 2 shows a further cross-sectional configuration of a tube with inner ribs, each of which has the cross-sectional shape of a tooth in gears with convexly outwardly curved flanks,
  • 3 shows a third cross-sectional shape of a tube, in which each inner rib has the cross-sectional shape of an isosceles, acute triangle with concave inwardly incident leg sides,
  • 4 is a perspective view of the tube of Fig. 1 with dashed lines indicated twisting of the inner ribs,
  • 5 shows the tube of FIG. 4 in a partially cutaway perspective view with flows indicated by arrows and FIG
  • 6 shows an exemplary schematic diagram of a heat exchanger for use of the tubes according to FIGS. 1 to 5.

    • In Fig. 1 ist eine erste Ausführungsform des erfindungsgemäßen Rohres 1 dargestellt. Dabei bildet die Querschnittsform einer jeden Rippe 2 ein spitzes, gleichschenkeliges Dreieck mit gerade verlaufenden Schenkelseiten 2a, 2b, dessen Dreieckspitze 2c mittels eines Radius r abgerundet in die beiden Schenkelseiten 2a, 2b übergeht. Jeweils zwei benachbarte Innenrippen 2 bilden einen im Querschnitt trapezförmigen Zwischenraum 2d.In Fig. 1 is a first embodiment of the inventive tube 1 shown. This forms the Cross-sectional shape of each rib 2 a pointed, isosceles Triangle with straight leg sides 2a, 2b, whose Triangle tip 2c rounded by a radius r in the two Leg sides 2a, 2b passes. Two adjacent each Inner ribs 2 form a trapezoidal in cross-section Gap 2d.

    Im Ausführungsbeispiel der Fig. 2 weist eine jede Innenrippe 3 des Rohres 1 die Form eines Zahnes bei Zahnrädern mit konvex nach außen gewölbten Seitenflanken 3a, 3b mit einer abgerundeten Zahnspitze 3c auf. Dabei umgreifen zwei benachbarte Rippen 3 einen im Querschnitt U-förmigen Zwischenraum 3d mit konvex eingefallenen Seitenflächen, die identisch mit der Form der Seitenflanken 3a, 3b der Rippen 3 sind.In the exemplary embodiment of FIG. 2, each inner rib 3 of the tube 1, the shape of a tooth in gears with convex outside curved side flanks 3a, 3b with a rounded Tooth tip 3c on. Two adjacent ribs 3 surround one in cross-section U-shaped space 3d with convex sunken side surfaces that are identical to the shape of the Side edges 3a, 3b of the ribs 3 are.

    In Fig. 3 ist eine weitere Querschnittsform offenbart. Dabei bildet der Querschnitt einer jeden Innenrippe 4 ein gleichschenkeliges, spitzes Dreieck mit konkav nach innen einfallenden Schenkelseiten 4a, 4b mit einer halbkreisförmigen Spitze 4c. Jeweils zwei benachbarte Innenrippen 4 umgreifen U-förmig einen im Querschnitt trapezförmigen Zwischenraum 4d, dessen Trapezschenkel konvex nach außen gewölbt sind und identisch mit den Schenkelseiten 4a, 4b sind.In Fig. 3, another cross-sectional shape is disclosed. there the cross-section of each inner rib 4 forms a isosceles, pointed triangle with concave inward incident leg sides 4a, 4b with a semicircular Tip 4c. In each case surround two adjacent inner ribs 4 U-shaped a cross-section trapezoidal space 4d, whose trapezoidal legs are curved convexly outward and identical to the leg sides 4a, 4b.

    Jedes Rohr 1 ist mit mindestens vier Innenrippen 2, 3, 4, im vorliegenden Fall mit jeweils acht Innenrippen 2, 3, 4 versehen. Die freien Enden 2c, 3c, 4c sind mit den Spitzen der Querschnittsformen der einzelnen Innenrippen 2, 3, 4 identisch. Dabei muß allerdings beachtet werden, daß die Spitzen sich auf den flächigen Querschnittskörper eines Dreiecks, hingegen die freien Enden sich auf einen verdrallt zur Symmetrielängsachse 5 erstreckenden räumlichen Körper beziehen. Diese freien Enden 2c, 3c, 4c weisen zur Symmetrielängsachse 5 des Rohres 1 einen Abstand a auf, der im Verhältnis zum Rohrinnendurchmesser d in einem Bereich von 1 : 12 bis 1 : 3 liegt.Each tube 1 is provided with at least four inner ribs 2, 3, 4, in present case, each with eight inner ribs 2, 3, 4 provided. The Free ends 2c, 3c, 4c are with the tips of the cross-sectional shapes the individual inner ribs 2, 3, 4 identical. It must, however be noted that the tips are on the flat Cross-sectional body of a triangle, whereas the free ends are on a twisted to the symmetry longitudinal axis 5 extending refer to spatial body. These free ends 2c, 3c, 4c have to the symmetry longitudinal axis 5 of the tube 1 a distance a, in the Ratio to the pipe inside diameter d in a range of 1: 12 to 1: 3 is.

    Und schließlich verlaufen sämtliche Innenrippen 2, 3, 4 gemäß der perspektivischen Darstellung der Fig. 4 zur Symmetrielängsachse 5 drallartig in gleicher Drallrichtung, hier z.B. nach links in Richtung des Pfeiles 6, und weisen die gleiche Drallänge L auf. Unter dieser Drallänge versteht man die Länge, die zwischen einer vollständigen 360°-Drallung einer Rippe liegt, d.h. die Länge L zwischen zwei Schnittebenen, zwischen denen nach einer 360°-Drallung eine jede Rippe wieder an der gleichen Stelle der ersten Schnittebene liegt.And finally all internal ribs 2, 3, 4 run according to the perspective view of FIG. 4 for Symmetrielängsachse 5 swirl-like in the same twisting direction, here e.g. to the left in the direction of the arrow 6, and point the same Twist length L on. Under this twist length is the length, the between a full 360 ° twist of a rib, i. the Length L between two cutting planes, between which after one 360 ° twisting each rib back to the same point of the first Cutting plane is located.

    Die Rohre sind vorteilhaft entweder aus einem stranggepreßten Aluminium oder Kupfer hergestellt oder in Kunststoff extrudiert. The tubes are advantageous either from an extruded Aluminum or copper produced or extruded in plastic.

    Die Wanddicke d1 des Rohres 1 ist abhängig vom Systemdruck und liegt in einem Bereich zwischen 0,4 mm und 3 mm.The wall thickness d 1 of the tube 1 is dependent on the system pressure and is in a range between 0.4 mm and 3 mm.

    Zur Vermeidung einer jedweden Strömungsunregelmäßigkeit ist die Querschnittskonfiguration des Rohres 1 mit seinen Innenrippen 2, 3, 4 und den Zwischenräumen 2d, 3d, 4d über die Länge L der Verdrallung in jedem Querschnitt gleich. Dadurch werden Drucksprünge und unerwünschte Störeffekte unterbunden, so daß die Kernströmung 7 und jede Querströmung 8 in den Zwischenräumen 2d, 3d und 4d miteinander kommunizieren und sich gegenseitig austauschen.To avoid any flow irregularity is the cross-sectional configuration of the tube 1 with its Inner ribs 2, 3, 4 and the spaces 2d, 3d, 4d on the Length L of the twisting in each cross section is the same. Thereby Pressure jumps and unwanted interference effects are prevented, so that the core flow 7 and each cross flow 8 in the Intervals 2d, 3d and 4d communicate with each other and exchange each other.

    Es versteht sich, daß die Rohre 1 auch aus anderen als die in den Figuren 1 bis 3 dargestellten Rohre bestehen können, daß also statt der dort dargestellten acht Rippen 2, 3, 4 beispielsweise nur vier Rippen 2, 3, 4 oder mehr als acht Rippen im Innenraum des Rohres 1 angeordnet sind. Denn die Anzahl der Rippen 2, 3, 4, die Länge L der Verdrallung sowie die Dicke und Rippenform werden in Abhängigkeit von der Art des Fluids und dessen Strömungsgeschwindigkeit sowie vom Druckabfall gestaltet. Dabei gilt die allgemeine Strömungsregel, daß der Druckabfall um so größer ist, je enger der freie Strömquerschnitt im Kernbereich sowie zwischen den Einzelrippen 2, 3, 4 ist, daß aber andererseits mit größerer Rippenanzahl und damit einhergehender größerer Wärmeübertragungsfläche auch die Wärmeübertragungsleistung passiv steigt.It is understood that the tubes 1 also other than those in Figures 1 to 3 shown tubes may consist, that is for example, only four, instead of the eight ribs 2, 3, 4 shown there Ribs 2, 3, 4 or more than eight ribs in the interior of the tube. 1 are arranged. Because the number of ribs 2, 3, 4, the length L of Twisting as well as the thickness and rib shape are dependent on the type of fluid and its flow velocity as well designed by the pressure drop. The general flow rule applies, that the smaller the free pressure, the greater the pressure drop Flow cross section in the core area and between the Single ribs 2, 3, 4, but that on the other hand with larger Number of ribs and larger size associated with it Heat transfer surface and the heat transfer performance passive rises.

    Bei dem erfindungsgemäßen Rohr 1 kommt aber der Verdrallung und der dadurch induzierten Querströmung zwischen dem Kernbereich in der Nähe der Symmetrielängsachse 5 und der Rohrinnenwandung 9 eine tragende Bedeutung zu. Diese ist in Fig. 5 veranschaulicht. Um die Symmetrielängsachse 5 des Rohres 1 bildet sich im freien Strömquerschnitt zwischen den Enden 2c, 3c, 4c der Rippen 2, 3, 4 eine Kernströmung 7, der aufgrund auch der Verdrallung der Endbereiche, die mit den Enden der Spitzen 2c, 3c, 4c übereinstimmen, ein Drall erteilt wird, der im dargestellten Fall ein Linksdrall ist, d.h. mit einer Drehung in der Zeichenebene im Gegenuhrzeigersinn verbunden ist, wie es der Pfeil 6 der Figuren 4 und 5 ausweist. Aufgrund der Verdrallung der Rippen 2 bzw. 3, 4 bildet sich in den Zwischenräumen 2d bzw. 3d, 4d eine Querströmung 8 aus, welche durch die darin eingezeichneten Pfeile angedeutet ist. Infolge dieser Querströmung 8, d.h. durch eine Strömung quer zur Symmetrielängsachse 5, findet ein äußerst intensiver Wärmetransport zwischen der Kernströmung 7 und der Innenwandung 9 des Rohres 1 statt. Aufgrund der hohen Wärmeleitfähigkeit λ des beispielsweise aus stranggepreßtem Aluminium oder Kupfer hergestellten Rohres 1 von
       209, 3 W/(mK) Aluminium
    und
       407,1 W/(mK) bei Kupfer
    erfolgt eine erhebliche Wärmeübertragungsleistung von der Kernströmung 7 über die Querströmung 8 an die Innenseite 9 des Rohres 1 und von dort weiter durch dessen Wand 10 mit der Dicke d1 auf die Außenseite 11 statt.    In the tube 1 according to the invention, however, the twisting and the transverse flow induced thereby between the core region in the vicinity of the symmetry longitudinal axis 5 and the tube inner wall 9 are of major importance. This is illustrated in FIG. 5. To the symmetry longitudinal axis 5 of the tube 1 is formed in the free flow cross section between the ends 2c, 3c, 4c of the ribs 2, 3, 4, a core flow 7, due to the twisting of the end portions, with the ends of the tips 2c, 3c, 4c coincide, a twist is issued, which is a left-hand twist in the illustrated case, that is connected to a rotation in the plane of the counterclockwise direction, as the arrow 6 of Figures 4 and 5 identifies. Due to the twisting of the ribs 2 or 3, 4, a transverse flow 8 forms in the intermediate spaces 2d or 3d, 4d, which is indicated by the arrows shown therein. As a result of this cross-flow 8, ie by a flow transverse to the symmetry longitudinal axis 5, an extremely intense heat transfer between the core flow 7 and the inner wall 9 of the tube 1 takes place. Due to the high thermal conductivity λ of the tube 1, for example, made of extruded aluminum or copper
    209, 3 W / (mK) aluminum
    and
    407.1 W / (mK) for copper
    There is a significant heat transfer performance of the core flow 7 through the cross flow 8 to the inside 9 of the tube 1 and from there through the wall 10 with the thickness d 1 on the outside 11 instead.

    Ein derartiges Rohr 1 findet beispielsweise Anwendung auf einem Rohrbündelwärmeübertrager 12, wie er in Fig. 6 dargestellt ist. Dabei tritt beispielsweise das Kühlmedium über den Stutzen 13 in die Rohre 1 ein und verläßt diese durch den Austritt 14. Im Gegenstrom tritt das beispielsweise zu kühlende Medium durch den Eintrittstutzen 15 an die Außenseite 11 der Rohre 1 ein und verläßt den Wärmeübertrager 12 in herabgekühltem Zustand durch den Auslaßstutzen 16. Es versteht sich, daß das erfindungsgemäße Rohr 1 sowohl zur Kühlung als auch zur Aufheizung von Fluiden Verwendung finden kann, je nachdem in welcher Richtung der Wärmeübertragungsvorgang stattfinden soll. Dabei gilt die allgemeine Regel, daß bei Fluiden mit großer Viskosität wie beispielsweise bei Ölen der Abstand a der freien Enden 2c, 3c, 4c der Innenrippen 2, 3, 4 von der Symmetrielängsachse 5 des Rohres 1 größer als bei Fluiden mit geringer Viskosität, wie Wasser und Gasen, zu bemessen ist. Such a tube 1 is used, for example a shell and tube heat exchanger 12, as shown in Fig. 6. In this case, for example, enters the cooling medium through the pipe 13 in the tubes 1 and exits through the outlet 14. Im Countercurrent occurs, for example, to be cooled medium through the Inlet 15 to the outside 11 of the tubes 1 and leaves the heat exchanger 12 in the cooled state by the Outlet 16. It is understood that the inventive Tube 1 both for cooling and for heating fluids Can be used, depending on the direction of the Heat transfer process to take place. The general applies here Typically, for high viscosity fluids such as Oiling the distance a of the free ends 2c, 3c, 4c of Inner ribs 2, 3, 4 of the symmetry longitudinal axis 5 of the tube first greater than low viscosity fluids such as water and gases, is to be measured.

    Bezugszeichenliste:LIST OF REFERENCE NUMBERS

    Rohrpipe
    11
    Innenrippeninternal ribs
    2, 3, 42, 3, 4
    Schenkelseiten der Innenrippe 2Legs of the inner rib 2
    2a, 2b2a, 2b
    Dreieckspitzetriangle top
    2c2c
    trapezförmiger Zwischenraumtrapezoidal space
    2d2d
    Seitenflanken der Innenrippe 3Side flanks of the inner rib 3
    3a, 3b3a, 3b
    Zahnspitzetooth tip
    3c3c
    U-förmiger ZwischenraumU-shaped space
    3d3d
    Schenkelseiten der Innenrippe 4Legs of the inner rib 4
    4a, 4b4a, 4b
    halbkreisförmige Spitzesemi-circular tip
    4c4c
    Zwischenraumgap
    4d4d
    Pfeilarrow
    66
    KernströmkanalKernströmkanal
    77
    Querströmungcrossflow
    88th
    Innenseite des Rohres 1Inside of the tube 1
    9 9
    Wand des Rohres 1Wall of the pipe 1
    1010
    Außenseite des Rohres 1Outside of the pipe 1
    1111
    RohrbündelwärmeübertragerShell and tube heat exchanger
    1212
    Eintritt in die Rohre 1Entry into the pipes 1
    1313
    Austrittexit
    1414
    Eintrittstutzeninlet connection
    1515
    Auslaßstutzenoutlet
    1616
    Abstand der freien Enden 2c, 3c, 4c zur Symmetrielängsachse 5Distance between the free ends 2c, 3c, 4c to the symmetry longitudinal axis 5
    aa
    RohrinnendurchmesserInside pipe diameter
    dd
    Wanddicke der Rohre 1Wall thickness of the tubes 1
    d1 d 1
    Drallängerate of twist
    LL
    Wärmeleitfähigkeitthermal conductivity
    λλ
    Radiusradius
    rr

    Claims (10)

    1. A pipe (1) having several internal ribs (2, 3, 4) with a spiral twist running with rotational symmetry with the longitudinal axis of symmetry (5) of the pipe (1), whereby the free ends (2c, 3c, 4c) of the internal ribs (2, 3, 4) are at a distance from the longitudinal axis of symmetry (5) of the pipe (1), which is in the range of 1:12 to 1:3 in relation to the inside diameter of the pipe, and all the internal ribs (2, 3. 4) run in the same direction (arrow 6) and with the same spiral length (11) with a spiral twist to the longitudinal axis of symmetry (5), whereby the cross-sectional shape of each internal rib (2) forms an acute equilateral triangle with straight legs (2a, 2b) whereof the triangular tip (2c) develops into the two legs (2a, 2b) with a rounded tip because of radius, with two adjacent internal ribs (2) forming an interspace (2d) having a trapezoidal cross section.
    2. The pipe (1) having several internal ribs (2, 3, 4) with a spiral twist running with rotational symmetry with the longitudinal axis of symmetry (5) of the pipe (1), whereby the free ends (2c, 3c, 4c) of the internal ribs (2, 3, 4) are at a distance from the longitudinal axis of symmetry (5) of the pipe (1), which is in the range of 1:12 to 1:3 in relation to the inside diameter of the pipe, and all the internal ribs (2, 3, 4) run in the same direction (arrow 6) and with the same spiral length (11) with a spiral twist to the longitudinal axis of symmetry (5). whereby the cross-sectional shape of each internal rib (3) of the pipe (1) has the shape of the tooth of gear wheels with side flanks (3a, 3b) with a convex outward curvature and with a rounded tip of the tooth, and two adjacent ribs extend around an interspace (3d) having a U-shaped cross section with side faces having a concave curvature.
    3. The pipe (1) having several internal ribs (2, 3, 4) with a spiral twist running with rotational symmetry with the longitudinal axis of symmetry (5) of the pipe (1), whereby the free ends (2c, 3c, 4c) of the internal ribs (2, 3, 4) are at a distance from the longitudinal axis of symmetry (5) of the pipe (1), which is in the range of 1:12 to 1:3 in relation to the inside diameter of the pipe, and all the internal ribs (2, 3, 4) run in the same direction (arrow 6) and with the same spiral length (11) with a spiral twist to the longitudinal axis of symmetry (5), whereby the cross-sectional shape of each internal rib (4) has an acute equilateral triangle with legs (4a, 4b) having a concave inward curvature and a semicircular shape at the tip(4c), with two adjacent internal ribs (4) extending in a U-shape around an interspace (4d) having a trapezoidal cross section, the trapezoidal legs having an outward convex curvature.
    4. The pipe as claimed in any one of Claims 1 to 3, characterised in that the pipe (1) with its internal ribs (2, 3, 4) is made of extruded aluminium or copper or extruded plastic in one piece.
    5. The pipe as claimed in any one of Claims 1 to 4, characterised in that the cross-sectional configuration of the pipe (1) with its internal ribs (2, 3, 4) and the interspaces (2d, 3d, 4d) is the same over the length (L) of the twist in each cross-sectional plane.
    6. The pipe as claimed in any one of Claims 1 to 5, characterised in that the wall thickness (di) of the pipe (1) is between 0.4 mm and 3 mm, depending on the system pressure.
    7. The pipe as claimed in any one of Claims 1 to 6, characterised in that it (1) has at least four internal ribs (2, 3, 4).
    8. The pipe as claimed in any one of Claims 1 to 7, characterised in that the number of ribs (2, 3, 4), the length (L) of the twist, the thickness and the shape of the ribs (2, 3, 4) are selected as a function of the type of fluid and its flow rate as well as the pressure drop.
    9. The pipe as claimed in any one of Claims 1 to 8, characterised in that the distance (a) of the free ends (2c, 3c, 4c) internal ribs (2, 3, 4) from the longitudinal axis of symmetry (5) of the pipe (1) is selected to be larger in the case of high-viscosity fluids such as oils than in the case of low-viscosity fluids such as water and gases.
    10. The pipe as claimed in any one of Claims 1 to 9, characterised in that the free ends (2c, 3c, 4c) of the internal ribs (2, 3, 4) are always at a distance (a) from the longitudinal axis of symmetry (5) even with low-viscosity fluids, such that a core flow channel (7) is formed between its free ends (2c, 3c, 4c) in each cross-sectional level of the pipe (1).
    EP01117802A 2000-08-03 2001-07-21 Heat exchange tube with twisted inner fins Expired - Lifetime EP1178278B1 (en)

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    DE10038624A DE10038624C2 (en) 2000-08-03 2000-08-03 Heat transfer tube with twisted inner fins
    DE10038624 2000-08-03

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    EP1178278A2 EP1178278A2 (en) 2002-02-06
    EP1178278A3 EP1178278A3 (en) 2004-01-07
    EP1178278B1 true EP1178278B1 (en) 2005-11-30

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    EP (1) EP1178278B1 (en)
    AT (1) ATE311581T1 (en)
    DE (2) DE10038624C2 (en)
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    Families Citing this family (44)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    US6872070B2 (en) * 2001-05-10 2005-03-29 Hauck Manufacturing Company U-tube diffusion flame burner assembly having unique flame stabilization
    US20050271663A1 (en) * 2001-06-28 2005-12-08 Domantis Limited Compositions and methods for treating inflammatory disorders
    DK1399484T3 (en) * 2001-06-28 2010-11-08 Domantis Ltd Double-specific ligand and its use
    DK1517921T3 (en) * 2002-06-28 2006-10-09 Domantis Ltd Immunoglobulin single variable antigen binding domains and double specific constructs thereof
    US9321832B2 (en) * 2002-06-28 2016-04-26 Domantis Limited Ligand
    EP1378719A1 (en) 2002-07-04 2004-01-07 Maschinenfabrik Georg Kiefer GmbH Tube with swirl element
    EP1578801A2 (en) * 2002-12-27 2005-09-28 Domantis Limited Dual specific single domain antibodies specific for a ligand and for the receptor of the ligand
    JP2005083741A (en) * 2003-09-05 2005-03-31 Lg Electronics Inc Air conditioner having heat exchanger and refrigerant switching means
    US20050126757A1 (en) * 2003-12-16 2005-06-16 Bennett Donald L. Internally enhanced tube with smaller groove top
    KR100539570B1 (en) * 2004-01-27 2005-12-29 엘지전자 주식회사 multi airconditioner
    JP4651366B2 (en) * 2004-12-02 2011-03-16 住友軽金属工業株式会社 Internal grooved heat transfer tube for high-pressure refrigerant
    US7182128B2 (en) * 2005-03-09 2007-02-27 Visteon Global Technologies, Inc. Heat exchanger tube having strengthening deformations
    US20060288602A1 (en) * 2005-06-04 2006-12-28 Lg Electronics Inc. Heat exchanger for dryer and condensing type dryer using the same
    JP2009503299A (en) * 2005-07-29 2009-01-29 ロバート， エー． ベンソン， Transportation of products from submarine wells
    BRPI0619225A2 (en) * 2005-12-01 2017-11-07 Domantis Ltd domain antibody monomer, ligand, isolated and recombinant nucleic acids, vector, host cell, method for producing a ligand dab monomer, pharmaceutical composition, drug delivery device, use of a domain antibody monomer, and, method to treat an inflammatory disease, arthritis or respiratory disease
    US8162040B2 (en) * 2006-03-10 2012-04-24 Spinworks, LLC Heat exchanging insert and method for fabricating same
    DE102006045650B4 (en) * 2006-09-27 2008-08-21 Techeffekt Anstalt Heat exchanger with a helical channel for a forced flow
    US20120186792A1 (en) * 2006-11-08 2012-07-26 Thomas Middleton Semmes Architecturally And Thermally Improved Freeze Resistant Window Perimeter Radiator
    US8385672B2 (en) * 2007-05-01 2013-02-26 Pictometry International Corp. System for detecting image abnormalities
    DE102007047726A1 (en) 2007-10-05 2009-04-09 Rieter Automatik Gmbh Extrusion device for extruding molten synthetic material, has heating insert comprising elongated base, where external dimensions of base is formed in such manner that base is inserted into opening in starting valve in form-fit manner
    JP2009162395A (en) * 2007-12-28 2009-07-23 Showa Denko Kk Double-wall-tube heat exchanger
    US20100212875A1 (en) * 2009-02-23 2010-08-26 Kun-Jung Chang Tubular heat dispersing structure
    US9945620B2 (en) * 2011-08-01 2018-04-17 Thomas Middleton Semmes Freeze damage resistant window perimeter radiator
    CA2861893A1 (en) 2012-01-19 2013-07-25 Joseph Dugan Internally heated fluid transfer pipes with internal helical heating ribs
    DE202012012741U1 (en) 2012-06-23 2013-11-19 Denis Blaffert-Kapfer Strangheizprofil
    US8755682B2 (en) 2012-07-18 2014-06-17 Trebor International Mixing header for fluid heater
    AU2013317799B2 (en) * 2012-09-21 2018-11-22 Ng1 Technologies, Llc Pipeline systems and methods
    JP6391140B2 (en) * 2012-12-27 2018-09-19 三菱アルミニウム株式会社 Manufacturing method of internally spiral grooved tube
    DE102013002097B4 (en) 2013-02-05 2020-02-27 Volkswagen Aktiengesellschaft Method for producing a coolable tool part for a molding tool for hot forming and / or press hardening, and a molding tool produced therewith
    US9249917B2 (en) * 2013-05-14 2016-02-02 General Electric Company Active sealing member
    US9713838B2 (en) 2013-05-14 2017-07-25 General Electric Company Static core tie rods
    EP2851628A3 (en) 2013-08-26 2015-08-05 Robert Bosch Gmbh Heat exchanger module with cyclone fins and heat exchanger cell formed from this module
    DE102013020469A1 (en) * 2013-12-06 2015-06-11 Webasto SE Heat exchanger and method for producing a heat exchanger
    US20160231065A1 (en) * 2015-02-09 2016-08-11 United Technologies Corporation Heat exchanger article with hollow tube having plurality of vanes
    GB201513415D0 (en) * 2015-07-30 2015-09-16 Senior Uk Ltd Finned coaxial cooler
    CN109416172B (en) * 2016-07-07 2021-06-08 西门子股份公司 Steam generator pipe with a swirl mount
    US10988904B2 (en) * 2016-08-18 2021-04-27 Ian R. Cooke Snow and ice melting device, system and corresponding methods
    US10539371B2 (en) * 2017-01-18 2020-01-21 Qorvo Us, Inc. Heat transfer device incorporating a helical flow element within a fluid conduit
    CZ201777A3 (en) 2017-02-09 2018-06-20 SUAR.CZ s.r.o. An annular heat exchanger
    US20190257592A1 (en) * 2018-02-20 2019-08-22 K&N Engineering, Inc. Modular intercooler block
    MX2021013280A (en) * 2019-05-03 2022-04-06 Hydro Extrusion Usa Llc Ribbed extruded electrical conduit.
    US11549644B2 (en) 2019-07-09 2023-01-10 Seatrec, Inc. Apparatus and method for making internally finned pressure vessel
    CN111256211B (en) * 2020-01-20 2021-11-26 海信（山东）空调有限公司 Air conditioner
    CN112948970A (en) * 2021-03-01 2021-06-11 西北工业大学 Design method of spiral evaporation tube structure based on spherical convex fins

    Family Cites Families (25)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    US1519673A (en) * 1921-08-01 1924-12-16 Doble Lab Heater
    US1881610A (en) * 1930-07-11 1932-10-11 Mccord Radiator & Mfg Co Tubing
    US2463997A (en) * 1944-06-19 1949-03-08 Calumet And Hecla Cons Copper Method of making integral external and internal finned tubing
    US2731709A (en) * 1950-09-18 1956-01-24 Brown Fintube Co Method of making internally finned heat exchanger tubes
    US2930405A (en) * 1955-05-31 1960-03-29 Brown Fintube Co Tube with internal fins and method of making same
    US3267564A (en) * 1964-04-23 1966-08-23 Calumet & Hecla Method of producing duplex internally finned tube unit
    US3528494A (en) * 1966-11-07 1970-09-15 Teledyne Inc Heat pipe for low thermal conductivity working fluids
    US3705617A (en) * 1970-11-05 1972-12-12 Badger Co Sublimation apparatus and method
    GB1334458A (en) * 1971-06-30 1973-10-17 Atomic Energy Authority Uk Heat exchange members
    AT325727B (en) * 1973-01-23 1975-11-10 Wikstroem Ab Berth ELECTRIC AIR HEATER
    DE7422107U (en) * 1973-07-05 1974-09-26 Universal Oil Prod Co Finned tube
    CA1063097A (en) * 1976-01-26 1979-09-25 David F. Fijas Inner finned heat exchanger tube
    DE2615168A1 (en) * 1976-04-07 1977-10-27 Gartner & Co J HEAT TRANSFER DEVICE WITH AT LEAST ONE LONGITUDINAL FIBER PIPE
    DE2703341C2 (en) * 1977-01-27 1983-01-27 Geb. Patorova Antonina Ivanovna Berdjugina Mandrel for extrusion of tubes with internal ribs
    DE2814828C3 (en) * 1978-04-06 1981-07-09 Metallgesellschaft Ag, 6000 Frankfurt Gas cooler with internally ribbed lead pipes
    DE3334964A1 (en) * 1983-09-27 1985-04-18 Wolf Klimatechnik GmbH, 8302 Mainburg Internally finned tube for gas- or oil-heated heating boilers
    JP2726480B2 (en) * 1989-03-02 1998-03-11 古河電気工業株式会社 Heat transfer tube
    DE9203670U1 (en) * 1991-03-15 1992-05-21 Joh. Vaillant Gmbh U. Co, 5630 Remscheid Fin heat exchanger
    AT401431B (en) * 1992-08-11 1996-09-25 Steyr Nutzfahrzeuge HEAT EXCHANGER
    MX9305803A (en) * 1992-10-02 1994-06-30 Carrier Corp HEAT TRANSFER TUBE WITH INTERNAL RIBS.
    JP3001181B2 (en) * 1994-07-11 2000-01-24 株式会社クボタ Reaction tube for ethylene production
    GB9420946D0 (en) * 1994-10-18 1994-12-07 Univ Manchester Heat transfer tube
    US5655599A (en) * 1995-06-21 1997-08-12 Gas Research Institute Radiant tubes having internal fins
    DE19609641C2 (en) * 1996-03-12 1999-05-06 Kiefer Gmbh Maschf G G Method and system for cooling a room
    JP3811909B2 (en) * 1997-03-21 2006-08-23 三菱電機株式会社 Heat transfer tube and heat exchanger using the same

    Also Published As

    Publication number Publication date
    ATE311581T1 (en) 2005-12-15
    DE10038624C2 (en) 2002-11-21
    EP1178278A2 (en) 2002-02-06
    US6533030B2 (en) 2003-03-18
    DE50108221D1 (en) 2006-01-05
    US20020014328A1 (en) 2002-02-07
    EP1178278A3 (en) 2004-01-07
    DK1178278T3 (en) 2006-04-03
    DE10038624A1 (en) 2002-02-21

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