JP2007187357A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure heat exchanger performance irrespective of variations in brazing in a heat exchanger having a plurality of partitions in annular space, especially low in height, by providing a terminal structure for ensuring the passage of the annular space, and thus preventing the passage of the annular space, serving as a second fluid passage, from being clogged. <P>SOLUTION: At first openings 4a having small diameter portions 5 and large diameter portions 6 into a branch pipe 4, outer tube terminals 3a are projected to the large diameter portions 6. With a space 8 much wider than clearance to the small diameter portions 5 defined around outer tubes 3, even if much brazing material 9 flows when the first openings 4a are brazed, it reaches the large diameter portions 6, which can disable seeping capillarity to ensure even the passage of a finned annular space susceptible to brazing material clogging, especially low in height. The single branch pipe 4 can implement the branching of water and carbon dioxide in two double pipes 1, and the separation of carbon dioxide into two double pipes 1, to provide a reduced number of part items and a simplified structure. <P>COPYRIGHT: (C)2007,JPO&INPIT

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.

  7 is a side view of a conventional heat exchanger described in Patent Document 1, and FIG. 8 is a cross-sectional view of a joint portion.

  As shown in FIGS. 7 and 8, the conventional heat exchanger 100 is installed so as to cover the inner tube 101 having an inner tube 101 having a double wall composed of an inner wall 101a made of titanium and an outer wall 101b made of copper. 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 of the present invention includes a plurality of double pipes and a branch pipe, and the double pipe includes an inner pipe through which a first fluid flows and an inner pipe of the inner pipe. An outer tube that covers the outer periphery and flows a second fluid to an annular portion between the inner tube and the annular portion has a plurality of partitions, and the branch tube includes a plurality of first openings and a plurality of openings. A second opening and a third opening, and the first opening and the second opening are paired to form a plurality of the pairs. The opening has a small diameter part and a large diameter part toward the inside of the branch pipe in the tube axis direction of the outer pipe, and projects the outer pipe terminal part to at least the large diameter part, so that the small diameter The second opening is exposed from the outer pipe terminal portion and penetrates the inside of the branch pipe. It is obtained by covering the inside tube.

  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.

  In addition, by having a plurality of pairs of the first opening and the second opening to be paired, the first fluid and the second fluid in the plurality of double pipes are branched, and the second fluid is divided into a plurality of branches. Can be done with one branch tube.

  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.

  Moreover, the number of parts of the heat exchanger terminal can be reduced, and the structure can be simplified.

  The invention according to claim 1 includes a plurality of double pipes and branch pipes, and the double pipe includes an inner pipe through which a first fluid flows, an outer circumference of the inner pipe and the inner pipe. An outer pipe that allows a second fluid to flow through the annular part between the pipes, the annular part having a plurality of partitions, and the branch pipe includes a plurality of first openings, a plurality of second openings, and a first The first opening and the second opening form a plurality of pairs, and the first opening is a tube of the outer tube. A space that has a small-diameter portion and a large-diameter portion toward the inside of the branch pipe in the axial direction, and projects the outer pipe terminal portion to at least the large-diameter portion, and is sufficiently wider than a gap with the small-diameter portion. And the second opening covers the inner pipe that is exposed from the outer pipe terminal and penetrates the inside of the branch pipe. That.

  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.

  In addition, by having a plurality of pairs of the first opening and the second opening to be paired, the first fluid and the second fluid in the plurality of double pipes are branched, and the second fluid is divided into a plurality of branches. Since it is one branch pipe, the number of parts of the heat exchanger terminal can be reduced and the structure can be simplified. Furthermore, since a single branch pipe splits into multiple pipes, the space inside the branch pipe becomes wider, and the second fluid is equalized in the branch pipe as the space increases. Therefore, the current can be divided more evenly.

  The invention according to claim 2 is the invention according to claim 1, wherein the branch pipe includes a main body portion and a lid portion, and the main body portion includes the first opening portion and the second opening portion. , Has.

  As a result, by using a two-part system consisting of a main body and a lid, in the production of branch pipes, the shape of the material such as pipes, plates, and blocks and the options for the processing method increase. For example, the main body uses a pipe. The branch pipe can be manufactured at a lower cost.

  Further, since the first opening and the second opening located on substantially the same straight line are concentrated on the main body, positioning and processing of the first opening and the second opening can be easily performed.

  The invention according to claim 3 is the invention according to claim 1 or 2, characterized in that 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 according to the embodiment. FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a diagram illustrating a flow of carbon dioxide at a terminal portion of the heat exchanger according to the embodiment. FIG. 5 is a cross-sectional view of a terminal portion of another heat exchanger according to the embodiment.

  1 to 4, the heat exchanger 1X has two double tubes 1 as a main body. The double pipe 1 has a double wall and an inner pipe 2 through which water flows, and an outer pipe 3 that covers the outer periphery of the inner pipe 2 and flows carbon dioxide in an annular portion between the inner pipe 2; Consists of. Here, the outer diameter of the outer tube 3 is 11 to 15 mm, the thickness is 1 to 2 mm, the outer diameter of the inner tube 2 is 7 to 11 mm, and the thickness of the double wall is 1 to 2 mm. The height h of the annular portion in the gap between the inner tube 2 and the outer tube 3 is 0.2 to 0.8 mm. A branch pipe 4 is provided at the terminal of the two double pipes 1.

  The branch pipe 4 has two first openings 4a, two second openings 4b, and one third opening 4c. A pair of first opening 4a and second opening 4b are located on substantially the same straight line, and two pairs of first opening 4a and second opening 4b are located substantially in parallel. Each first opening 4a has a small-diameter portion 5 and a large-diameter portion 6 toward the inside of the branch tube 4 in the tube axis direction of the outer tube 3, covers the outer tube 3, and covers the terminal portion 3a of the outer tube 3. It protrudes to the large diameter part 6 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. The allowance S to the terminal portion 3a of the outer tube 3 protruding from the large-diameter portion 6 of the first opening 4a is 0.8 to 1.8 times the outer diameter of the outer tube 3, and the outer diameter of the outer tube 3 is In the case of 12.7 mm, the allowance S is 10 mm, the height H of the branch pipe 4 is about 45 mm, and the width W is about 35 mm.

  The outer tube 3 has a plurality of fins 7 on the inner wall, the tips of the fins 7 are in contact with the inner tube 2 to partition the annular portion, and the flow path of the annular portion is secured. In the present embodiment, eight fins 7 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 addition, when the dimension of the annular portion in the radial direction of the double pipe 1 is the annular portion height, in particular, by reducing the annular portion height, the annular portion is made an ultrathin channel to simulate the microchannel, and the By reducing the equivalent diameter of carbon, heat transfer can be promoted and high heat exchange efficiency can be obtained. Here, the microchannel literally refers to a minute flow path. 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, heat transfer The balance between rate and pressure loss is good, and the heat exchanger can be made smaller and lighter.

  If the height of the annular portion is lowered, the annular portion is easily crushed, so fins 7 are provided to secure the flow path. When the fin 7 is provided, when the first opening 4 a of the branch pipe 4 is brazed to the end of the double pipe 1, the fin 7 itself becomes a path along which the brazing material is transmitted. And easily clogged with wax. 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 6 and the space 8 sufficiently wider than the gap with the small diameter portion 5 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 it passes through the small diameter part 5 and reaches the large diameter part 6, the capillary phenomenon that is osmotic force does not occur. The brazing material 9 does not reach the portion 3a. Therefore, even if the annular portion having the fins 7 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 clogging with wax. Therefore, heat exchange performance can be ensured regardless of variations in brazing work.

  Further, by inserting the outer tube terminal portion 3a deeply to the large-diameter portion 6, even if the strength of the outer tube 3 is reduced due to heating during brazing of the first opening 4a, the small-diameter portion 5 that is a joining portion is always provided. Since it is a double wall, the pressure strength can be secured and the reliability of the pressure strength can be secured.

  Further, in FIG. 4, after the outer tube terminal portion 3 a protrudes to the inside of the branch pipe 4, carbon dioxide is once stored in a wide space inside the branch pipe 4 from the narrow annular portion, and is brought into a pressure-equalized state. Since carbon dioxide is drawn into the annular portion with the fins 7 by the differential pressure across the outer tube terminal portion 3a, the carbon dioxide can be evenly distributed around the inner tube 2.

  In FIG. 1, the branch pipe 4 on the side from which carbon dioxide flows out is referred to as a branch pipe 4 ′.

  In the case where carbon dioxide flows out, carbon dioxide flows out in a state rectified by the fins 7 to the outer tube terminal portion 3a in the branch pipe 4 ', so that regardless of the distance to the third opening 4c, 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.

  Further, by having two pairs of the first opening 4a and the second opening 4b, the water and carbon dioxide in the two double tubes 1 are branched, and the carbon dioxide is separated into two double tubes 1 Therefore, the number of parts at the terminal portion of the heat exchanger 1X can be reduced, and the structure can be simplified. Further, since one branch pipe 4 divides the flow into the two double pipes 1, the space 8 inside the branch pipe 4 becomes a wider space, and the larger the space 8 of carbon dioxide, the wider the space 8, the branch pipe 4. Since the pressure is equalized internally, the flow can be divided more evenly.

  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 branch pipe 4 is shown in a cylindrical configuration. However, as shown in FIG. 5, the first opening 4a, the second opening 4b, and the third opening 4c are formed in the copper block. You may cut and make. When manufactured with a copper block, the reliability of pressure strength can be secured.

  In the embodiment of the present invention, the branch pipe 4 is shown as a two-pass branch pipe for diverting to two double pipes 1, but the present invention is not limited to this. The same effect can be obtained in the case of four passes for four passes.

  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. However, the same effect can be obtained with a refrigerant operating at a high pressure such as R410A.

  The fin 7 may be provided on the outer wall of the inner tube 2, and the tip of the fin 7 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 7 are provided on the same circumference. However, two or more fins 7 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 7 is integrated with the outer tube 3, but a columnar material may be inserted between the inner tube 2 and the outer tube 3 to partition the annular portion.

(Embodiment 2)
FIG. 6 is a cross-sectional view of the terminal portion of the heat exchanger according to Embodiment 2 of the present invention.

  In FIG. 6, the branch pipe 4 includes a main body portion 10 and a lid portion 11, and the main body portion 10 has two first opening portions 4 a, two second opening portions 4 b, and one third opening portion 4 c. And.

  As a result, by using a two-part system consisting of the main body 10 and the lid 11, in the production of the branch pipe 4, the shape of the material such as the pipe, plate, and block and the options for the processing method increase, and the branch pipe is less expensive. Can be produced. For example, the main body 10 of FIG. 6 can be manufactured by diverting a tube and adding post-processing.

  Moreover, since the 1st opening part 4a and the 2nd opening part 4b concentrate on the main-body part 9, positioning and a process of the 1st opening part 4a and the 2nd opening part 4b can be performed easily. In particular, when the first opening 4a and the second opening 4b are positioned on substantially the same straight line, the manufacturing becomes easy. For example, by using a single diameter drill, drilling can be performed once.

  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 of the terminal part of the heat exchanger in the embodiment Sectional drawing of the terminal part of the other heat exchanger in the embodiment Sectional drawing of the terminal part of the heat exchanger in Embodiment 2 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 1 double pipe 2 inner pipe 3 outer pipe 3a outer pipe terminal 4 branch pipe 4 'branch pipe 4a first opening 4b second opening 4c third opening 5 small diameter section 6 large diameter section 7 fin 8 Space 10 Body 11 Cover

Claims (3)

  The double pipe includes a plurality of double pipes and a branch pipe. The double pipe covers the outer circumference of the inner pipe and the second fluid in an annular portion between the inner pipe and the inner pipe. The annular pipe has a plurality of partitions, and the branch pipe has a plurality of first openings, a plurality of second openings, and a third opening. One of the first openings and one of the second openings form a plurality of pairs, and the first opening is inside the branch pipe in the tube axis direction of the outer pipe. A small diameter portion and a large diameter portion, and projecting the outer tube end portion to at least the large diameter portion so that a space sufficiently wider than the gap with the small diameter portion is provided on the outer periphery of the outer tube. The heat exchanger according to claim 1, wherein the second opening covers the inner pipe exposed from the outer pipe terminal and penetrating through the branch pipe.   The heat exchanger according to claim 1, wherein the branch pipe includes a main body portion and a lid portion, and the main body portion includes the first opening portion and the second opening portion.   The heat exchanger according to claim 1 or 2, wherein the first fluid is water and the second fluid is carbon dioxide.

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