JP2005090926A - Double pipe type heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double pipe type heat exchanger with high heat exchange efficiency without increase in size. <P>SOLUTION: A double pipe 1 comprises an inner pipe 2 through which a refrigerant flows, an outer pipe 3 arranged concentrically outside the inner pipe 2, and a partition body 4 which partitions, in the longitudinal direction, a space formed between the inner pipe 2 and the outer pipe 3. The partition body 4 comprises a body part 4C fitted into the outer periphery of the inner pipe 2, and a fin 4A expanding radially from one end of the body part 4C and having a cutout part 4B. The plurality of partition bodies 4 are arranged so that the cutout parts 4B are in a zigzag shape with respect to the longitudinal direction. A refrigerant R such as carbon dioxide gas is allowed to flow into the inner pipe 2 and a fluid W to be cooled such as water is allowed to flow through a flow path 7 outside the inner pipe 2. Water branches into both the sides of the inner pipe 2. The branched water streams flow in the direction normal to the inner pipe 2 and join in the cutout part 4B. Then, the joined water flows through the cutout part 4B to a next flow path 7. At this time, heat exchange between the carbon dioxide gas refrigerant flowing through the inner pipe 2 and water is carried out. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a double tube heat exchanger using a double tube in which an outer tube and an inner tube are arranged concentrically, and in particular, a double tube heat exchanger excellent in heat exchange efficiency without increasing its size. Regarding the exchanger.

  In a conventional double-tube heat exchanger using a double tube in which an outer tube and an inner tube are arranged concentrically, one using a leak detection tube as an inner tube is known (for example, Patent Documents). 1).

  FIG. 5 shows a double pipe used in the double pipe heat exchanger described in Patent Document 1. The double pipe 30 is arranged concentrically on the outer side of the inner pipe 10 through which the refrigerant R such as carbon dioxide flows, and the outer pipe through which the fluid W to be cooled such as water flows between the inner pipe 10. 20 and a spiral flow path 20 </ b> C in which a spring is spirally inserted between the inner tube 10 and the outer tube 20 using a special tool or device, and the fluid W to be cooled flows spirally along the inner tube 10. The heat transfer promoting body 25 is formed.

  The inner tube 10 includes a first tube 10A having an inner tube heat transfer promoting body 12 made of a twisted tape or the like, a second tube 10B formed in contact with the outside thereof, and a first tube 10A. A leakage detection groove 10C formed continuously between the second pipe 10B in the longitudinal direction of the double pipe 30 and formed at the end of the leakage detection groove 10C. A detection unit that detects the cooling fluid W.

  According to this double tube heat exchanger, the detection unit detects the coolant R such as carbon dioxide and water to be cooled such as water leaked into the leakage detection groove 10C due to damage of the inner tube 10 and the outer tube 20 or the like. Therefore, it is possible to prevent the refrigerant R and the fluid W to be cooled from mixing due to the inner tube 10 being damaged.

Further, according to this double tube heat exchanger, the medium to be cooled W flows through the spiral flow path 20C formed in a spiral shape along the heat transfer promoting body 25, so that the flow path length is increased. Can do.
Japanese Patent Laid-Open No. 2001-201275 (FIG. 5)

  However, according to the conventional double tube heat exchanger, if the height of the heat transfer accelerator 25 is increased to increase the heat transfer area in order to increase the heat exchange efficiency, the double tube becomes large. As a result, the double-pipe heat exchanger increases in size.

  Accordingly, an object of the present invention is to provide a double-pipe heat exchanger that is excellent in heat exchange efficiency without increasing its size.

  In order to achieve the above object, the present invention is arranged concentrically between an inner tube through which a first fluid flows and an outer side of the inner tube, and exchanges heat with the first fluid between the inner tube and the inner tube. By dividing the outer tube through which the second fluid flows and the space formed between the inner tube and the outer tube into a plurality of regions along the longitudinal direction, the first fluid flows in a direction perpendicular to the flow direction. There is provided a double-tube heat exchanger comprising a plurality of partitions forming a vertical flow path in a direction.

  According to the double tube heat exchanger of the present invention, the second fluid flows in a direction perpendicular to the direction in which the first fluid flows through the space formed between the inner tube and the outer tube by the plurality of partitions. Since the flow path is formed, the length of the flow path can be increased, so that a double pipe heat exchanger excellent in heat exchange efficiency can be obtained without increasing the size.

  FIG. 1 shows a part of a double pipe used in a double pipe heat exchanger according to an embodiment of the present invention, and FIG. 2 is a right side view of the double pipe seen from the direction A in FIG. Indicates. The double pipe 1 is disposed concentrically on the outside of the inner pipe 2 and the inner pipe 2 through which the refrigerant as a first fluid such as carbon dioxide, ammonia, and flon flows. The outer tube 3 through which the fluid to be cooled as the second fluid such as water flows, and the space formed between the inner tube 2 and the outer tube 3 are partitioned into a plurality of regions along the longitudinal direction. And a plurality of partitions 4 forming a flow path 7 having a vertical flow path 7A in a direction perpendicular to the flow direction.

  The inner pipe 2 is provided with a leak detection pipe portion 2A extending in the longitudinal direction on the peripheral wall thereof. If the refrigerant or the fluid to be cooled oozes out into the leak detection pipe portion 2A, the refrigerant or the fluid to be cooled is detected by the detection portion (not shown). It is possible to prevent the refrigerant and the fluid to be cooled from being mixed due to the inner pipe 2 being damaged by detection by the detection unit.

  The partition body 4 includes a body portion 4C that is fitted to the outer periphery of the inner tube 2 and fins 4A that extend in the radial direction from the peripheral side of one end of the body portion 4C. The fin 4 </ b> A has a cut portion 4 </ b> B in which a part on the outer edge side is cut out, and is formed perpendicular to the length direction of the inner tube 2. A plurality of the partitions 4 are arranged such that the positions of the cut portions 4B are staggered along the longitudinal direction of the inner tube 2. That is, the excision part 4 is disposed at a site that is point-symmetric with respect to the center line along the longitudinal direction of the inner tube 2.

  A method for manufacturing the double tube 1 will be briefly described. First, the inner tube 2 having the leak detection tube portion 2A on the inner wall is prepared, and the body portion 4C of the partition 4 is sequentially inserted and fixed to the inner tube 2 so that the cut portion 4B is in a predetermined arrangement. Next, the outer tube 3 is fitted on the outside thereof.

  FIG. 3 shows a cross section of the double tube 1 shown in FIG. The function of the partition 4 is demonstrated using this FIG. When the refrigerant R flows inside the inner tube 2 and the fluid to be cooled W flows through the flow path 7, the heat of the fluid W to be cooled is transferred to the inside of the inner tube 2 through the fins 4A and the body portion 4C. The heat of R and the heat of the cooled fluid W exchange heat. This heat exchange is related to the area of the fin 4A and the area of the body 4C where heat transfer is performed if the flow rates of the refrigerant R and the fluid W to be cooled are constant. The number of 4 and the interval are determined. Further, since the vertical flow path 7A in the direction perpendicular to the direction in which the refrigerant R flows is formed, the contact length between the refrigerant R and the fluid W to be cooled is increased, and the heat transfer area is substantially increased. Here, the flow rate of the fluid to be cooled W in the flow path 7 is set so as to flow in a turbulent state. This is because in the laminar flow state, the heat resistance between the body 4C and the flow path 7 is increased, so that heat transfer is not sufficiently performed.

  FIG. 4 shows a double-pipe heat exchanger according to an embodiment of the present invention. The double pipe heat exchanger 5 is formed by bending the double pipe 1 into a hollow coil shape and laminating it in the vertical direction, and is bound by a band 6 so as not to lose its shape. An inner tube inlet 2B and an outer tube outlet 3C are provided at one end of the double tube 1, and an inner tube outlet 2C and an outer tube inlet 3B are provided at the other end.

  In the double pipe heat exchanger 5, when the refrigerant R is supplied from the inner pipe inlet 2B to the inside of the inner pipe 2 and the cooled fluid W is supplied from the outer pipe inlet 3B to the flow path 7, the cooled fluid W is As shown in FIG. 3, the flow path 7 in which the cut portions 4B are arranged in a staggered manner passes in the direction indicated by the arrow. At this time, the to-be-cooled fluid W that has entered the vertical flow path 7A from the excision part 4B is diverted around the inner pipe 2 by the inner pipe 2, and merges at the excision part 4B that is the outlet of the vertical flow path 7A. . By repeating such diversion and merging, the fluid W to be cooled is stirred and heat exchange with the refrigerant R is performed. The refrigerant R is supplied again from the inner pipe outlet 2C to the inner pipe inlet 2B via a refrigerant circulation system (not shown).

According to the above-described embodiment, the following effects can be obtained.
(1) Since the flow path 7 formed between the inner pipe 2 and the outer pipe 3 forms the vertical flow path 7A by the partition body 4, the contact length between the refrigerant R and the fluid W to be cooled becomes longer. The heat transfer area is substantially increased, and as a result, the heat exchange efficiency can be increased.
(2) Since the double pipe 1 forms the partition 4 on the outer side of the inner pipe 2 and the outer pipe 3 is supported at a number of points by the outer edges of the fins 4A, the double pipe 1 is concentric at the bent portion even if it is bent Can keep sex. Therefore, a constant heat exchange efficiency can be obtained regardless of the position in the longitudinal direction of the double pipe 1.
(3) The double pipe 1 can be formed by simply fitting the inner pipe 2 into which the body 4C of the partition 4 is fitted into the outer pipe 3 without using a special tool or device as in the prior art. Therefore, a double-pipe heat exchanger can be easily manufactured.
(4) Since the heat transfer area can be increased by increasing the number of partitions 4 formed in the inner pipe 2 by shortening the length of the body portion 4C, the heat exchange efficiency can be further increased. .

  The fins 4A of the partition 4 are provided perpendicular to the longitudinal direction of the inner tube 2, but may be inclined at a predetermined angle with respect to the longitudinal direction of the inner tube or twisted. And the double pipe 1 which has the flow path 7 which has various heat exchange efficiency by combining these partition bodies 4 is obtained. Further, the cut portions 4B of the partition 4 are arranged in a zigzag shape along the longitudinal direction of the inner tube 2, but may be arranged by changing a predetermined angle. Further, the fin 4A may protrude in the radial direction from any portion of the outer peripheral surface of the body portion 4C. Further, the cut portion 4B is not limited to the outer edge side of the fin 4A, and may be formed at an arbitrary site on the center side. In addition to the above, the cut portion 4B may be formed by, for example, a large hole or a large number of small holes.

It is the perspective view which fractured and showed a part of double pipe used for the double pipe type heat exchanger concerning an embodiment of the invention. It is the right view seen from the R direction of FIG. It is sectional drawing of the double pipe | tube shown in FIG. It is a figure which shows the double pipe type heat exchanger which concerns on embodiment of this invention. It is the perspective view which fractured | ruptured and showed a part of double tube used for the conventional double tube type heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Double pipe 2 Inner pipe 2A Leak detection pipe part 2B Inner pipe inlet 2C Inner pipe outlet 3 Outer pipe 3B Outer pipe inlet 3C Outer pipe outlet 4 Fin part 4A Fin 4B Cutting part 4C Trunk part 5 Double pipe type heat exchanger 6 Band 7 Flow path 7A Vertical flow path 10 Inner pipe 10A First pipe 10B Second pipe 10C Leak detection groove 12 Inner pipe heat transfer promotion body 20 Outer pipe 25 Heat transfer promotion body 30 Double pipe

Claims (5)

An inner tube through which the first fluid flows;
An outer tube disposed concentrically outside the inner tube and through which a second fluid that exchanges heat with the first fluid flows between the inner tube and the inner tube;
A plurality of partitions forming a vertical flow path in a direction perpendicular to a direction in which the first fluid flows by dividing a space formed between the inner tube and the outer tube into a plurality of regions along the longitudinal direction. A double-pipe heat exchanger characterized by comprising a body.   The double pipe heat exchanger according to claim 1, wherein the inner pipe includes a leak detection pipe.   The said partition is provided with the cylindrical part inserted by the outer side of the said inner pipe, and the plate-shaped body which spreads in radial direction from the outer peripheral surface of the said cylindrical part. Double pipe heat exchanger.   4. The double-tube heat exchange according to claim 3, wherein the plurality of partitions are formed with cut portions on an outer edge side of the plate-like body, and the plurality of cut portions are arranged in a staggered manner. vessel. The double-pipe heat exchanger according to claim 3, wherein the plate-like body is provided perpendicularly to the longitudinal direction of the inner tube or at a predetermined angle.

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