Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
  • F28F3/02—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations
  • F28F3/04—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element
  • F28F3/042—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element in the form of local deformations of the element
  • F28F3/046—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element in the form of local deformations of the element the deformations being linear, e.g. corrugations
• • 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
  • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
  • F28F1/24—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely
  • F28F1/32—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely the means having portions engaging further tubular elements
• • 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
  • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
  • F28F1/24—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely
  • F28F1/32—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely the means having portions engaging further tubular elements
  • F28F1/325—Fins with openings
• • 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
  • Y10S165/454—Heat exchange having side-by-side conduits structure or conduit section
  • Y10S165/50—Side-by-side conduits with fins
  • Y10S165/505—Corrugated strips disposed between adjacent conduits

Definitions

• the invention relates to a finned tube heat exchanger according to the features in the preamble of claim 1.
• the finned tube heat exchanger according to DE-PS 34 19 734 is able to condense large amounts of steam. It also has the northern part that a pressure equalization between all areas of the tube cross-section occurs at every point of the heat exchanger tubes. As a result, the condensation of the exhaust steam in the front pipe sections facing the flow direction of the cooling air ends at exactly the same point as in the pipe sections rear in the flow direction of the cooling air. Dead zones can thus hardly be established. In addition, relatively large pipe cross sections are formed, so that the flow pressure losses due to the larger hydraulic cross section are considerably reduced. The fins protruding perpendicularly from the surfaces of the heat exchanger tubes are smooth and non-protruding.
• the finned tube heat exchanger of DE-OS 19 58 909 has leading edges integrated into the fins between the heat exchanger tubes.
• the leading edges are formed by pressing out surface sections from the planes of the ribs.
• the cooling air finds obstacles.
• the heat transfer is improved by this measure, but the disadvantage is paid that the pressure loss increases several times due to the leading edges.
• the invention is based on the object of perfecting such a finned tube heat exchanger in such a way that the external heat transfer between the cooling air and the surfaces of the heat exchanger tubes can be increased significantly without a substantial increase in the pressure loss.
• the ribs are then provided on at least one side surface with a zigzag-shaped configuration having air guide grooves.
• the air guide grooves generally have a longitudinal extension in the direction of flow of the cooling air. They are open at the fin ends and thus allow the cooling air to flow in the air guide grooves, with the zigzag-shaped configuration significantly improving the external heat transfer between the cooling air and the surface of the heat exchanger tubes is reached without significantly increasing the pressure losses.
• the air guide grooves can extend over the entire side surface of a rib. They are usually provided by appropriate embossing on both sides of a rib. In this case, the air guide grooves of adjacent ribs face each other frontally.
• the fins configured according to the invention can be provided individually on each heat exchanger tube. However, it is particularly advantageous if two heat exchanger tubes running side by side are connected in a web-like manner by ribs with air guide grooves running in a zigzag shape. These can be individual ribs or ribbed ribbons embossed in a U-shaped or trapezoidal shape.
• the air guide grooves are curved in a wave shape
• a preferred embodiment according to claim 2 is seen in that the mutually angled groove sections of the air guide grooves run in a straight line.
• the groove sections are preferably of the same length.
• each transition section is advantageously curved in a circular arc.
• the radii of the transition sections are expediently designed identically.
• a particularly advantageous embodiment of the rib design is seen in the features of claim 4. These are either individual ribs which are fixed to the heat exchanger tubes via the fastening strips, or the ribs form part of corrugated, U-shaped or trapezoidal ribbed strips which are connected to the heat exchanger tubes via the fastening strips.
• 15 areas from the fields to the fastening strip can preferably be carried out on a suitable embossing machine.
• the transition sections In order to ensure that the cooling air in the air-guiding grooves is deflected as swirl-free as possible, the transition sections have a radius of 1.5 mm to 3 mm.
• the distance between a transverse plane intersecting a center of curvature and the intersection of the adjacent center lines is Groove sections with the line of symmetry about 3 mm to 10 mm, preferably about 7.5 mm.
• the air guide grooves have a semicircular cross section with a radius and a depth of approximately 1 mm to 2 mm, preferably approximately 1.5 mm.
• the uniform course of the air guide grooves - preferably on both side surfaces of the ribs - is optimized in accordance with claim 10 in that the distance between the center lines of two adjacent air guide grooves is approximately 4.5 mm to 6 mm, preferably approximately 5.0 mm. This results in a ratio of the distance of two transverse planes intersecting in the longitudinal direction of an air guiding groove to the center of curvature intersecting to the distance of the center lines of two adjacent air guiding grooves of approximately 3.5-4.5: 1, preferably 4: 1. Finally, a further improvement in the heat transfer conditions can be achieved in that the distance between two adjacent ribs is approximately 2 mm to 4 mm, preferably approximately 3 mm.
• FIG. 1 shows a vertical cross section through a section of a finned tube heat exchanger in the diagram
• Figure 2 is a partial view of the finned tube heat exchanger according to arrow II of Figure 1;
• Figure 3 shows an enlarged view of section III of Figure 1;
• FIG. 5 shows an enlarged cross section through the illustration of FIG. 3 along the line V-V;
• FIG. 6 shows a section of a U-shaped ribbed belt in perspective
• FIG. 7 shows a side view of the rib band of FIGS. 6 and 6
• FIG. 8 shows a top view of the ribbed band of FIG. 6.
• FIGS. 1 to 3 in FIGS. 1 to 3 represent a partial area of a finned tube heat exchanger for condensing the exhaust vapors of large turbine systems by means of cooling air.
• the finned tube heat exchanger 1 has a plurality of heat exchanger tubes 2, which are arranged in parallel at a distance A and have an elongated cross section.
• the heat exchanger tubes 2 are connected to one another by fins 3, which extend parallel to the direction of flow SR of the cooling air and are fastened perpendicularly to the lateral surfaces 4 of the heat exchanger tubes 2 by means of suitable fixing strips.
• FIG. 1 shows that the length L of the cross section of the heat exchanger tubes 2 is several times larger than the width B.
• the ribs 3 (FIGS. 2 and 5) arranged at a distance of AI of 3 mm from one another have on both side surfaces 5 in a zigzag configuration parallel to one another and continuous in the flow direction SR of the cooling air, open at the fin ends 6, air guide grooves 7, which are formed by a corresponding embossing of the ribs 3 with a thickness D of approximately 0.1 mm for aluminum or copper or approximately to 0.5 mm for steel (FIGS. 1 to 5).
• Each air guide groove 7 is made up of straight groove sections 8 and two successive groove sections 8 continuously connecting the arcuate transition sections 9 (FIGS. 1, 3 and 4).
• FIG. 4 shows the geometrical relationships of an air guide groove 7 in an enlarged representation on the basis of the emphasized center lines 10 of two successive groove sections 8. It can then be seen that the arcuate transition sections 9 are semicircularly curved.
• the center of curvature 11 of the transition sections 9 are at a distance from the symmetry line SL of the air guide groove 7.
• the transition sections 9 have a radius Rl of 1.5 mm to 3 mm.
• the distance A2 from two successive centers of curvature 11 intersecting transverse planes (E) is 10 mm.
• the intersection 12 of the center lines 10 of two successive groove sections 8 is arranged at a distance A3 of 3.5 mm from the symmetry line SL.
• the air guide grooves 7 have a semicircular cross section with a radius R and a depth T of 1.5 mm.
• the distance A4 of the center lines 10 of two adjacent air guide grooves is 5.0 mm (FIGS. 1 and 5).
• the U-shaped ribbed belt 13 of FIGS. 6 to 8 consists of a plurality of ribs 3a and fastening strips 14, 14a connecting the ribs 3a, which at the same time also serve to fix the ribbed belt 13 to the heat exchanger tubes 2.
• the ribs 3a are divided in the longitudinal direction into a plurality of successively zigzag fields 15, each with parallel groove sections 8a.
• the groove sections 8a form constituents of air guide grooves 7a which extend over the length of the ribs 3a.
• the longitudinal edges 16, 17 of the fields 15 run both at an angle l to the fastening strips 14, 14a extending in the parallel planes El-E1, E2-E2 and at an angle ⁇ 1 to the longitudinal edges 18, 19 of each rib 3a intersecting plane E3-E3.
• the angles ⁇ , ⁇ l, ß, ßl are 14 °.
• the design of the ribs 3a and the air guide grooves 7a formed on the ribs 3a corresponds to the design of the ribs 3 and the air guide grooves 7 of the embodiment of FIGS. 1 to 5, so that a further explanation can be dispensed with.

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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)
• Accessories For Mixers (AREA)

Applications Claiming Priority (5)

Publications (2)

Family

ID=25934323

Family Applications (1)

Country Status (9)

Families Citing this family (44)

Family Cites Families (10)

• 1995
  • 1995-02-23 CA CA002162051A patent/CA2162051A1/en not_active Abandoned
  • 1995-02-23 AU AU18885/95A patent/AU1888595A/en not_active Abandoned
  • 1995-02-23 CN CN95190131A patent/CN1124057A/zh active Pending
  • 1995-02-23 JP JP7522624A patent/JPH08510047A/ja active Pending
  • 1995-02-23 US US08/535,191 patent/US5623989A/en not_active Expired - Lifetime
  • 1995-02-23 WO PCT/DE1995/000239 patent/WO1995023949A1/de not_active Application Discontinuation
  • 1995-02-23 EP EP95911195A patent/EP0697090B1/de not_active Expired - Lifetime
  • 1995-02-23 BR BR9505782A patent/BR9505782A/pt not_active Application Discontinuation
  • 1995-02-23 CZ CZ952879A patent/CZ287995A3/cs unknown

Non-Patent Citations (1)

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