JP2007187360A - Heat exchanger - Google Patents

Abstract

In a heat exchanger having a plurality of partitions in an annular part, especially when the height of the annular part is low, the partition serves as a path through which the brazing material is transmitted. Since the flow path of the annular part which is a path is closed, there is a problem that it is difficult to ensure heat exchange performance.
In a first opening 4a having a small-diameter portion 6 and a large-diameter portion 7 toward the inside of a branch pipe 4 in the tube axis direction of the outer tube 3, the outer tube terminal portion 3a protrudes to the large-diameter portion 7. Let By providing a space 8 sufficiently wider than the gap with the small diameter portion 6 on the outer periphery of the outer tube 3, even if a large amount of brazing material 9 flows into the branch tube 4 by brazing the first opening 4 a, the large diameter When the portion 7 is reached, the capillary phenomenon that is the osmotic force does not occur, so the brazing material 9 does not reach the outer tube terminal portion 3a. Therefore, even when the annular portion having a fin that is easily wax-packed has a low annular portion height, it is not clogged with wax, and a carbon dioxide channel can be secured.
[Selection] Figure 2

Description

  The present invention relates to a structure of a terminal portion for branching two kinds of fluids of a heat exchanger in which two kinds of fluids exchange heat.

  Conventionally, in this type of heat exchanger, a structure in which two types of fluid are branched at the pipe end, a structure in which a T-shaped joint and a modified joint are combined (for example, see Patent Document 1), or a modified T in which these are integrally molded. Mold joints are often used.

  Hereinafter, the structure of a branch portion of a conventional heat exchanger will be described with reference to the drawings.

  10 is a side view of a conventional heat exchanger described in Patent Document 1, and FIG. 11 is a cross-sectional view of a joint portion.

  As shown in FIG. 10 and FIG. 11, the conventional heat exchanger 100 is installed so as to cover the inner tube 101 having a double wall composed of an inner wall 101a made of titanium and an outer wall 101b made of copper, and the inner tube 101. It consists of a copper outer tube 102 and a copper joint 103.

  The joint 103 includes a T-shaped joint member 104 and a modified joint member 105. The connecting portion 104 a of the T-shaped joint member 104 is brazed with the outer tube 102, and the connecting portion 104 b of the T-shaped member 104 is brazed with the large-diameter portion 105 a of the odd-shaped joint member 105. The small-diameter portion 105b of the odd-shaped joint member 105 is brazed to the inner tube 101 that is exposed from the terminal portion of the outer tube 102 and penetrates the inside. A joint such as a socket (not shown) is welded or brazed to a terminal portion of the inner tube 101, and fluid flows into and out of the inner tube 101 through this portion.

  On the other hand, a joint such as a socket (not shown) is welded or brazed to the connection portion 104c of the T-shaped joint member 104, and a refrigerant or an annular portion between the inner tube 101 and the outer tube 102 is passed through this portion. Allow fluids such as heat medium to flow in and out.

  The operation of the heat exchanger configured as described above will be described below.

  A fluid such as a refrigerant circulates in the inner tube 101, and a liquid such as water that exchanges heat flows in an annular portion between the inner tube 101 and the outer tube 102, and the double wall of the inner tube 101 is formed. Heat is exchanged, and fluid such as refrigerant and liquid such as water exchange heat.

The inner tube 101 has high corrosion resistance because the inner wall 101a is made of titanium. Further, by using a double wall with the copper outer wall 101b, titanium that is expensive and has low thermal conductivity can be thinned and manufactured at low cost, and heat exchange efficiency is improved by copper having high thermal conductivity. Furthermore, since the outer tube 102 and the joint 103 are made of copper, they are easily available and can be joined by brazing or welding.
Registered Utility Model No. 3026515

  However, in the configuration of the heat exchanger 100 described in the above-mentioned conventional Patent Document 1, when a large amount of brazing material flows when the T-shaped joint member 104a is brazed to the outer tube 102, the brazing material propagates through the gap by capillary action. Reaches the terminal portion of the outer tube 102, and the annular portion is brazed. When the height of the annular part is low, it is necessary to partition the fins and other members in order to prevent the flow path from collapsing. In particular, when the annular part has a plurality of partitions such as fins, the partition itself However, this is the route that the brazing material travels.

  Wax clogging greatly reduces the heat exchange performance by significantly reducing the flow path or completely blocking it, resulting in uneven flow distribution or a flow path through which refrigerant does not flow. There was a problem of ending up.

  The present invention solves the above-described conventional problems, and is a heat exchanger having a plurality of partitions in the annular portion, and particularly when the annular portion has a low height, regardless of variations in brazing work, the flow of the annular portion is reduced. An object of the present invention is to provide a terminal part structure capable of securing a road.

  In order to solve the above-described conventional problems, the heat exchanger according to the present invention causes the second fluid to flow through an inner tube through which the first fluid flows and an annular portion covering the outer periphery of the inner tube and the inner tube. The annular pipe has a plurality of partitions, and the branch pipe has a first opening, a second opening, and a third opening. The opening and the second opening are located on substantially the same straight line, and the first opening has a small diameter portion and a large diameter portion toward the inside of the branch pipe in the tube axis direction of the outer pipe. And projecting the outer tube terminal portion to at least the large diameter portion so as to cover the outer tube outer periphery with a space sufficiently wider than the gap with the small diameter portion, and the second opening portion The inner pipe that is exposed from the pipe end portion and penetrates the inside of the branch pipe is covered.

  As a result, the outer tube terminal portion protrudes to at least the large diameter portion, and a space sufficiently wider than the gap with the small diameter portion is provided on the outer tube outer periphery, so that a large amount of brazing is applied when brazing the first opening. Even if the material flows, if it passes the small diameter part of the first opening and reaches the large diameter part, the capillary phenomenon that is osmotic force will not occur, so the brazing material will not reach the outer tube end part, and it is easy to braze Even in the annular portion having the partition, the flow path is not clogged.

  In addition, by inserting the outer tube end deeply into the large-diameter portion, even if the strength of the outer tube is reduced due to the heating at the time of joining the first opening, the small-diameter portion and the outer wall of the outer tube always become a double wall. Since the strength is high and the terminal portion is located at the end, the pressure resistance strength can be secured.

  Here, when there is no partition in the annular portion, the second fluid tends to drift to the third opening side that is the outflow inlet in the annular portion of the outer tube terminal portion, and the heat exchange in the annular portion is biased by the drift. Arise.

  However, in the present invention, when the second fluid flows into the annular part, the outer pipe terminal part protrudes to the inside of the branch pipe, so that the second fluid is once accumulated in the wide branch pipe and the pressure is equalized. After that, the second fluid is drawn into the annular portion having a partition by the differential pressure before and after the outer tube terminal portion, so that it can be evenly distributed around the inner tube. In addition, when the second fluid flows out from the annular portion, the second fluid flows out in a state rectified by the partition of the annular portion, so that the second portion of the annular portion of the outer tube terminal portion is irrespective of the distance to the third opening. Does not cause drift in the fluid.

  Since the heat exchanger of the present invention has a structure of the terminal portion that can secure the flow path of the annular portion, it has a plurality of partitions in the annular portion, particularly in a structure where the annular portion has a low height and is easily clogged with wax. However, heat exchange performance can be secured regardless of variations in brazing work.

  Further, reliability can be ensured with respect to pressure strength.

  In addition, since the annular portion of the outer tube terminal portion protruding inside the branch pipe has a plurality of partitions, when the second fluid flows into the annular portion of the outer tube terminal portion, it is evenly distributed around the inner tube. When the flow can be diverted and flows out from the annular portion of the outer tube terminal portion, it can be made to flow out evenly, so that uniform heat exchange can be performed in the annular portion over the entire length of the outer tube.

  The invention according to claim 1 includes: an inner pipe for flowing a first fluid; an outer pipe for covering the outer periphery of the inner pipe and flowing a second fluid to an annular portion between the inner pipe; and a branch pipe. The annular portion has a plurality of partitions, the branch pipe has a first opening, a second opening, and a third opening, and the first opening and the second opening are Located on substantially the same straight line, the first opening has a small diameter portion and a large diameter portion toward the inside of the branch pipe in the tube axis direction of the outer pipe, and at least the outer pipe terminal portion The second opening is exposed from the outer tube terminal portion and protrudes so as to protrude to the large diameter portion so as to have a space sufficiently wider than the gap between the small diameter portion and the outer tube. The inner tube that penetrates the inside of the tube is covered.

  As a result, the outer tube terminal portion protrudes to at least the large diameter portion, and a space sufficiently wider than the gap with the small diameter portion is provided on the outer tube outer periphery, so that a large amount of brazing is applied when brazing the first opening. Even if the material flows, if it passes through the small diameter part of the first opening and reaches the large diameter part, the capillary phenomenon that is osmotic force will not occur, the brazing material will not reach the outer tube terminal part, and it is easy to braze Since the flow path can be secured even in the annular portion having the partition, particularly the annular portion having a low height, the heat exchange performance can be ensured regardless of the variation in the brazing operation.

  In addition, by inserting the outer tube end deeply into the large-diameter portion, even if the strength of the outer tube is reduced due to the heating at the time of joining the first opening, the small-diameter portion and the outer wall of the outer tube always become a double wall. Since the strength is high and the terminal portion is located at the tip, the pressure strength can be secured and the reliability can be secured.

  Further, by projecting the outer pipe terminal part inside the branch pipe, the second fluid is temporarily stored in a wide space inside the branch pipe, and the accumulated second fluid is rectified by the partition of the annular part. Regardless of the distance to the opening, no drift occurs in the second fluid in the annular portion of the outer tube terminal portion. Therefore, when the second fluid flows into the annular portion of the outer tube terminal portion, it can be evenly divided around the inner tube, and when it flows out of the annular portion of the outer tube terminal portion, it is evenly distributed. Therefore, increase in pressure loss can be suppressed.

  The invention according to claim 2 is the invention according to claim 1, wherein the large-diameter portion has a tapered portion that gradually expands from the small-diameter portion, and the outer tube terminal portion is located in a section of the tapered portion. It is characterized by projecting so as to be located at.

  As a result, the second fluid flowing out at the outer tube terminal portion flows along the taper portion, so that generation of vortices generated around the outer tube terminal portion is suppressed as compared with the case where there is no taper portion. An increase in the pressure loss of the second fluid generated in the pipe portion can be suppressed.

  The invention according to claim 3 is the invention according to claim 1 or 2, further comprising a cylindrical material that covers the outer tube between the first opening and the outer tube, and a tube axis of the outer tube. In the direction, one end of the cylindrical material is located between the end portion of the first opening and the end portion of the outer pipe, and the other end of the cylindrical material is located outside the branch pipe from the end portion of the first opening. The small diameter portion and the large diameter portion of the first opening are provided by the cylindrical material.

  Thereby, the cylindrical material is sandwiched between the first opening and the outer tube, and one end of the cylindrical material is located between the first opening end and the outer tube terminal in the tube axis direction of the outer tube, Since the other end of the cylindrical material is located outside the branch pipe from the end of the first opening, the reaching distance of the brazing material that travels on the outer wall of the outer tube to the outer tube end is increased, and the thickness of the cylindrical material is increased. Since a space is created around the outer pipe, it is not necessary to change the cross section of the first opening of the branch pipe, so that it is possible to more reliably prevent clogging due to traveling along the outer wall of the outer pipe. Moreover, the structure of the branch pipe can be simplified.

  According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the modified cylindrical member is provided with a modified cylindrical material that covers the first opening and the outer tube, and the modified cylindrical member is disposed in a tube axis direction of the outer tube. One end of the material is located on the inner side of the branch pipe from the end of the first opening, and the other end of the modified cylindrical material is located on the outer side of the branch pipe from the end of the first opening. Both ends of the modified cylindrical member are joined to the outer tube and the branch tube, respectively.

  Thereby, the reach | attainment distance to the outer pipe | tube terminal part of the brazing material which propagates an outer pipe outer wall becomes long by connecting an outer pipe and a branch pipe with the unusual shape cylindrical material which covers a 1st opening part and an outer pipe. In addition, since the gap into which the brazing material enters becomes a U-shape, the flow resistance of the brazing material increases. Therefore, it is possible to more reliably prevent the clogging due to traveling along the outer wall of the outer tube.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, a groove is formed in a part of the outer wall of the outer pipe located inside the branch pipe from the end of the first opening. It is characterized by having provided.

  As a result, since the groove becomes a brazing material reservoir, it is possible to more reliably prevent brazing due to propagation along the outer wall of the outer tube. Moreover, since the pressure-resistant strength fall by a groove | channel becomes a double wall by being covered with a branch pipe, a cylindrical material, and a deformed cylindrical material, a pressure-resistant strength can be ensured and reliability can be ensured.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the first fluid is water and the second fluid is carbon dioxide.

  As a result, high heat exchange efficiency can be obtained as a heat exchanger, and high heat exchange efficiency can be obtained as a product, particularly when used in a heat pump type water heater.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, the same reference numerals are given to the same components as those of the above-described embodiment, and the detailed description thereof is omitted. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a side view of a heat exchanger according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of a terminal portion of the heat exchanger in the same embodiment. FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a diagram showing a flow of carbon dioxide in a terminal portion of the heat exchanger in the same embodiment. FIG. 5 is a cross-sectional view of a terminal portion of another heat exchanger according to the embodiment. FIG. 6 is an enlarged view of a portion B in FIG.

  1 to 4, a double pipe 1 which is a main body of the heat exchanger 1X includes an inner pipe 2 having a double wall and flowing water therein, an inner pipe 2 covering the outer periphery of the inner pipe 2, And an outer tube 3 for flowing carbon dioxide in the annular portion between them, and a branch tube 4 is provided at the end of the double tube 1.

  The outer tube 3 has a plurality of fins 5 on the inner wall, the tips of the fins 5 are in contact with the inner tube 2 to partition the annular portion, and a flow path of the annular portion is secured. The branch pipe 4 has a first opening 4a, a second opening 4b, and a third opening 4c, and the first opening 4a and the second opening 4b are located on substantially the same straight line. The first opening 4 a has a small diameter portion 6 and a large diameter portion 7 toward the inside of the branch tube 4 in the tube axis direction of the outer tube 3, covers the outer tube 3, and enlarges the terminal portion 3 a of the outer tube 3. It protrudes to the diameter portion 7 and is joined to the outer tube 3. The second opening 4 b is joined to the inner tube 2 so as to cover the inner tube 2 that is exposed from the outer tube terminal portion 3 a and penetrates the inside of the branch tube 4.

  In the present embodiment, eight fins 5 are provided on the same circumference.

  A joint such as a socket (not shown) is brazed to the terminal portion of the inner pipe 2, and water flows into and out of the inner pipe 2 through this portion. A pipe or the like (not shown) is brazed to the third opening 4c of the branch pipe 4, and carbon dioxide flows into and out of the annular portion between the inner pipe 2 and the outer pipe 3 through this portion. The inner tube 2, the outer tube 3, and the branch tube 4 are made of copper having good corrosion resistance and thermal conductivity.

  About the heat exchanger 1X comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In the double pipe 1, low-temperature water flows inside the inner pipe 2, and high-temperature carbon dioxide flows oppositely through the annular part between the inner pipe 2 and the outer pipe 3. Hot water is produced by heat exchange between water and carbon dioxide through the wall. Here, the inner pipe 2 is a double wall, and a double wall structure is formed between water and carbon dioxide, so that even if one pipe is corroded, water and carbon dioxide are not mixed, and safety is ensured. Can be secured. Moreover, although not shown, when a groove is provided between the double walls, leakage can be detected by communicating the groove with the atmosphere at the inner tube terminal portion.

  In particular, by reducing the height of the annular portion, it is possible to simulate a microchannel in the annular portion, reduce the fluid diameter of carbon dioxide, promote heat transfer, and obtain high heat exchange efficiency. For example, if the height of the annular portion through which carbon dioxide flows is 0.03 to 0.07 times the outer diameter of the inner tube, the heat transfer coefficient and pressure loss are well balanced, and the heat exchanger can be reduced in size and weight. .

  If the height of the annular portion is lowered, the annular portion is easily crushed, so fins 5 are provided to secure the flow path. When the fin 5 is provided, when the branch pipe 4 is brazed to the end of the double pipe 1, the fin 5 itself becomes a path along which the brazing material is transmitted, and is easier to clog compared to the case without the fin 5. . When the wax is clogged, a portion where carbon dioxide does not flow is generated in the annular portion, and the heat exchange performance as a heat exchanger is significantly reduced.

  However, in the present embodiment, the outer tube terminal portion 3a is protruded to the large diameter portion 7 and the space 8 sufficiently wider than the gap with the small diameter portion 6 is provided on the outer periphery of the outer tube 3, whereby the first Even if a large amount of brazing material 9 flows into the branch pipe 4 due to brazing of the opening 4a, if the small diameter portion 6 is passed and the large diameter portion 7 is reached, the capillary phenomenon that is osmotic force does not occur, so the outer tube terminal The brazing material 9 does not reach the portion 3a. Therefore, even if the annular portion having the fins 5 having a structure that is easily clogged with wax is low, particularly when the height of the annular portion is low, the clogging of carbon dioxide can be secured without being clogged with wax. Therefore, heat exchange performance can be ensured regardless of variations in brazing work.

  Moreover, even if the strength of the outer tube 3 is reduced by heating when brazing the first opening 4a by inserting the outer tube terminal portion 3a deeply into the large diameter portion 7, the small diameter portion 6 which is a joint portion is reduced. Since it is always a double wall, the strength is high, and the terminal portion 3a is located at the tip, so that the pressure resistance strength can be secured. Therefore, it is possible to ensure the reliability with respect to the pressure strength.

  Further, in FIG. 4, the outer tube terminal portion 3 a protrudes to the inside of the branch tube 4, so that carbon dioxide is once stored in a wide space inside the branch tube 4 to obtain a pressure-equalized state, and then the outer tube terminal. Since carbon dioxide is drawn into the annular portion with the fins 5 by the differential pressure across the portion 3a, it can be evenly distributed around the inner tube 2.

  Further, when carbon dioxide flows out from the annular portion, it flows out in a state rectified by the fin 5 of the annular portion, so that regardless of the distance to the third opening 4c, the annular portion of the outer tube terminal portion 3a Does not cause drift in carbon dioxide.

  Therefore, uniform heat exchange can be performed in the annular portion over the entire length of the outer tube 3.

  In addition, by using water as the first fluid and carbon dioxide as the second fluid, high heat exchange efficiency can be obtained as the heat exchanger 1X, and high heat pump efficiency can be obtained by using it as a water refrigerant heat exchanger for a heat pump water heater. Can be obtained.

  In the embodiment of the present invention, the outer tube 3 is shown as projecting into the branch tube 4 as it is. However, as shown in FIGS. 5 and 6, the inside of the branch tube 4 from the end of the first opening 4a. You may provide the groove | channel 10 in a part of outer wall of the outer tube | pipe 3 located in this. In addition, the groove | channel 10 is formed over the perimeter of the outer wall of the outer tube | pipe 3, and one groove | channel is provided. If the groove 10 is provided in the portion located inside the branch pipe 4 from the end of the first opening 4a, the groove 10 becomes a brazing material 9 pool, so that the brazing due to the propagation through the outer wall of the outer pipe 3 is more reliably performed. Can be prevented.

  Moreover, the pressure-resistant strength fall by the groove | channel 10 is covered with the branch pipe 4, and becomes a double wall, Therefore A pressure-proof strength is securable. Therefore, it is possible to ensure the reliability of the pressure strength.

  In the embodiment of the present invention, the material of the inner tube 2 and the outer tube 3 is usually made of copper, but the same effect can be obtained with brass, SUS, corrosion-resistant iron, aluminum alloy, or the like.

  In the embodiment of the present invention, carbon dioxide is used as the refrigerant flowing through the annular portion 4a. However, similar effects can be obtained with a refrigerant operating at a high pressure such as R410A.

  The fin 5 may be provided on the outer wall of the inner tube 2, and the tip of the fin 5 may be in contact with the inner wall of the outer tube 3 to partition the annular portion.

  In the embodiment of the present invention, eight fins 5 are provided on the same circumference. However, two or more fins may be provided, and more preferably, from the viewpoint of securing concentricity with the cross-sectional area of the flow path. Three points.

  In the embodiment of the present invention, the fin 5 is integrated with the inner tube 2, but a columnar material may be inserted between the inner tube 2 and the outer tube 3 to partition the annular portion.

  In the embodiment of the present invention, the number of the grooves 10 is one, but two or more grooves 10 may be provided in order to more reliably prevent the clogging.

(Embodiment 2)
FIG. 7 is a cross-sectional view of the terminal portion of the heat exchanger according to Embodiment 2 of the present invention.

  In FIG. 7, the large-diameter portion 7 has a tapered portion 7a and a straight portion 7b that gradually expand from the small-diameter portion 6, and the outer tube terminal portion 3a is protruded so as to be positioned in the section of the tapered portion 7a. Is.

  As a result, carbon dioxide flowing in and out at the outer tube terminal portion 3a flows along the taper portion 7a, so that generation of vortices around the outer tube terminal portion 3a is suppressed as compared with the case without the taper portion 7a. Thus, an increase in the pressure loss of carbon dioxide, which is the second fluid generated in the branch pipe 4 portion, can be suppressed.

(Embodiment 3)
FIG. 8 is a cross-sectional view of the terminal portion of the heat exchanger according to Embodiment 3 of the present invention.

  In FIG. 8, the cylindrical material 11 which covers the outer tube | pipe 3 is provided between the 1st opening part 4a and the outer tube | pipe 3, and one end of the cylindrical material 11 is the 1st opening part edge part 4a and the outer tube | pipe terminal part 3a. The other end of the cylindrical member 11 is located between the first opening end 4a and the outer side of the branch pipe 4, and the small diameter portion 6 and the large diameter portion 7 of the first opening 4a are connected to the cylindrical member 11 in the middle. 11 is provided.

  Thus, by sandwiching the cylindrical material 11 between the branch pipe 4 and the outer pipe 3, compared to the case where there is no cylindrical material 11, the brazing material 9 that travels along the outer wall of the outer pipe 3 up to the outer pipe terminal portion 3a. The reach is longer. Therefore, it is possible to more reliably prevent the clogging due to traveling along the outer wall of the outer tube.

  Moreover, since the space around the outer tube 3 is created by the thickness of the cylindrical material 11, it is not necessary to change the cross section of the first opening 4a of the branch tube 4 to make the diameter different. Therefore, the structure of the branch pipe 4 can be simplified. If the structure of the branch pipe 4 is simplified, the manufacturing cost of the branch pipe 4 can be reduced.

(Embodiment 4)
FIG. 9 is a cross-sectional view of the terminal portion of the heat exchanger according to Embodiment 4 of the present invention.

  In FIG. 9, a modified cylindrical material 12 covering the first opening 4a and the outer tube 3 is provided, and one end of the modified cylindrical material 12 is located inside the branch pipe 4 from the end of the first opening 4a. The other end of the material 12 is positioned outside the branch pipe 4 from the end of the first opening 4a, and both ends of the modified cylindrical material 12 are joined to the outer pipe 3 and the branch pipe 4, respectively.

  The atypical cylindrical material 12 is composed of two cylindrical portions having different outer diameters.

  Thus, by connecting the outer tube 3 and the branch tube 4 with the modified cylindrical material 12, the reach distance of the brazing material 9 traveling along the outer wall of the outer tube 3 to the outer tube terminal portion 3a becomes longer. Moreover, since the gap into which the brazing material 9 enters is a U-shape, the flow resistance of the brazing material 9 is increased. Therefore, it is possible to more reliably prevent the clogging due to traveling along the outer wall of the outer tube 3.

  As described above, the heat exchanger according to the present invention has a plurality of partitions having a structure that is easy to clog wax in the annular portion, and is not clogged with wax even when the height of the annular portion is low. Since it has a terminal structure that can secure a carbon flow path, it can also be applied to uses such as heat pump water heaters, home and commercial air conditioners, and fuel cells.

Side view of heat exchanger in Embodiment 1 of the present invention Sectional drawing of the terminal part of the heat exchanger in the embodiment AA line sectional view of FIG. The figure which shows the flow of the carbon dioxide in the terminal part of the heat exchanger in the embodiment Sectional drawing of the terminal part of the other heat exchanger in the embodiment Part B enlarged view of FIG. Sectional drawing of the terminal part of the heat exchanger in Embodiment 2 of this invention Sectional drawing of the terminal part of the heat exchanger in Embodiment 3 of this invention Sectional drawing of the terminal part of the heat exchanger in Embodiment 4 of this invention Side view of conventional heat exchanger Sectional view of the joint part of a conventional heat exchanger

Explanation of symbols

1X heat exchanger 2 inner pipe 3 outer pipe 3a outer pipe terminal 4 branch pipe 4a first opening 4b second opening 4c third opening 5 fin 6 small diameter 7 large diameter 7a taper 8 space 10 groove 11 Cylindrical material 12 Atypical cylindrical material

Claims (6)

  An inner pipe for flowing a first fluid; an outer pipe for covering the outer periphery of the inner pipe and flowing a second fluid to an annular portion between the inner pipe and a branch pipe; Having a partition, the branch pipe has a first opening, a second opening, and a third opening, the first opening and the second opening are located on substantially the same straight line, The first opening has a small-diameter portion and a large-diameter portion toward the inside of the branch pipe in the tube axis direction of the outer tube, and projects the outer tube terminal portion to at least the large-diameter portion. The outer tube is covered with a space sufficiently wider than the gap with the small-diameter portion, and the second opening is exposed from the outer tube terminal portion and penetrates the inner tube penetrating through the branch tube. A heat exchanger characterized by covering.   The said large diameter part has a taper part which expands gradually from the said small diameter part, and protruded the said outer tube | pipe terminal part so that it might be located in the area of the said taper part. Heat exchanger.   A cylindrical material that covers the outer tube is provided between the first opening and the outer tube, and one end of the cylindrical material is connected to the end of the first opening and the outer tube in the tube axis direction of the outer tube. The other end of the cylindrical member is located outside the branch pipe from the end portion of the first opening, and the small diameter portion and the large diameter portion of the first opening portion are positioned between the pipe end portions. The heat exchanger according to claim 1, wherein the heat exchanger is provided by the cylindrical material.   An irregular cylindrical material that covers the first opening and the outer pipe is provided, and one end of the irregular cylindrical material is positioned inside the branch pipe from the end of the first opening in the tube axis direction of the outer pipe. The other end of the irregular cylindrical member is positioned outside the branch pipe from the end of the first opening, and both ends of the irregular cylindrical member are joined to the outer pipe and the branch pipe, respectively. The heat exchanger according to claim 1 or 2, characterized by the above.   The heat exchanger according to any one of claims 1 to 4, wherein a groove is provided in a part of the outer wall of the outer pipe located inside the branch pipe from the end of the first opening.   The heat exchanger according to any one of claims 1 to 5, wherein the first fluid is water, and the second fluid is carbon dioxide.

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