JP2008057860A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger lightweight and low in cost with excellent heat exchange performance. <P>SOLUTION: The heat exchanger has a double tube 21 comprising an outer tube 23 and an inner tube 22 inserted in the outer tube 23. The inner tube 22 comprises a plurality of refrigerant tubes 26 formed with first fluid passages 24 inside, and one leakage detecting tube 27 covering the plurality of refrigerant tubes 26 and having a plurality of leakage detecting grooves 28 axially on the inner surface. A second fluid passage 25 is formed between the outside of the inner tube 22 and the internal wall of the outer tube 23. Since the applied amount of copper can be reduced while maintaining heat exchange performance, the weight and cost of the heat exchanger can be reduced. Further, since the cross-sectional area of the inner tube 22 is reduced, the tube diameter of the outer tube 23 can be reduced in the case of designing with the second fluid passage 25 as the same area. Alternatively, in the case of designing the tube diameter of the outer tube 23 as the same, the cross-sectional area of the second fluid passage 25 can be enlarged, and pressure loss in the second fluid passage 25 can be reduced to improve heat exchange performance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat exchanger used in a refrigeration cycle apparatus, and more particularly to a heat exchanger used as a hot water supply heat exchanger in a hot water supply apparatus.

  2. Description of the Related Art Conventionally, as a heat exchanger used for heat exchange between a refrigerant and water in a hot water supply device, an air conditioner, etc., a main part is configured by inserting a plurality of inner tubes into an outer tube. A heat exchanger composed of a heavy pipe has been proposed (see, for example, Patent Document 1).

  FIG. 7 is a cross-sectional view of a double tube of a conventional heat exchanger described in Patent Document 1.

  In FIG. 7, a double pipe 71 is composed of an outer pipe 73 and a plurality of inner pipes 72 inserted into the outer pipe 73 and having a refrigerant flow path 74 formed therein. A water flow path 75 is formed between the inner wall 73. The double pipe 71 is usually formed in a spiral shape, and both ends of the inner pipe 72 are connected to a refrigerant circuit built in a device such as a hot water supply device (not shown), and the outer pipe 73 By connecting both ends to a water circuit that is also built into the device, heat is exchanged between the refrigerant and water.

The inner pipe 72 includes a copper refrigerant pipe 76 and a copper leakage detection pipe 77 provided on the outer periphery of the refrigerant pipe 76. A plurality of leak detection grooves 78 are formed on the inner surface of the leak detection pipe 77 along the axial direction of the leak detection pipe 77, and an air layer is formed in the leak detection groove 78. Thereby, the refrigerant or water leaked from the refrigerant pipe 76 or the leak detection pipe 77 is leaked to the outside through the leak detection groove 78 without mixing.
JP 2005-147466 A

  However, in the configuration of the conventional heat exchanger, the inner pipe 72 is configured by inserting one refrigerant pipe 76 into one leak detection pipe 77, and the double pipe 71 is formed by one outer pipe 73. Therefore, there is a problem that the amount of copper used is increased, the weight of the heat exchanger is increased, and the cost is increased.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a heat exchanger that is excellent in heat exchange performance, uses less copper, is light in weight, and is low in cost.

  In order to solve the conventional problem, a heat exchanger according to the present invention includes a double pipe including an outer pipe and an inner pipe inserted into the outer pipe, and the inner pipe has a first fluid flow therein. A plurality of first fluid pipes formed with passages, and one leak detection pipe that covers the plurality of first fluid pipes and includes a plurality of leak detection grooves in the axial direction of the inner surface, and the inner pipe The second fluid flow path is formed between the outside of the outer tube and the inner wall of the outer tube, and the amount of copper used can be reduced while maintaining the performance of the heat exchanger. Reduction and cost reduction. In addition, since the cross-sectional area of the inner pipe is reduced, the diameter of the outer pipe can be reduced when the second fluid flow path is designed to have the same area. Alternatively, when the outer pipes are designed to have the same diameter, the cross-sectional area of the second fluid channel can be increased and the pressure loss in the second fluid channel can be reduced, so that the heat exchange performance is improved.

  The heat exchanger of the present invention is lightweight, inexpensive and excellent in heat exchange performance.

  1st invention is equipped with the outer tube and the double tube which consists of an inner tube inserted in the outer tube, and the inner tube has a plurality of 1st fluid tubes in which the 1st fluid channel was formed inside And a single leakage detection tube that covers the plurality of first fluid tubes and includes a plurality of leakage detection grooves in the axial direction of the inner surface, and is between the outer side of the inner tube and the inner wall of the outer tube. Since the second fluid passage is formed and the amount of copper used can be reduced while maintaining the performance of the heat exchanger, the weight of the heat exchanger can be reduced and the cost can be reduced. In addition, since the cross-sectional area of the inner pipe is reduced, the diameter of the outer pipe can be reduced when the second fluid flow path is designed to have the same area. Alternatively, when the outer pipes are designed to have the same diameter, the cross-sectional area of the second fluid channel can be increased and the pressure loss in the second fluid channel can be reduced, so that the heat exchange performance is improved.

  The second invention, in particular, is provided with a recess along the axial direction on the outer periphery of the leak detection tube of the first invention, the amount of copper used can be reduced while maintaining the performance of the heat exchanger, It is possible to reduce the weight and cost of the heat exchanger. Furthermore, when the cross-sectional area of the inner pipe is reduced and the second fluid flow path is designed to have the same area, the pipe diameter of the outer pipe can be reduced. Alternatively, when the outer pipe is designed with the same diameter, the cross-sectional area of the second fluid channel can be enlarged, and the pressure loss in the second fluid channel can be reduced, so that high performance can be achieved. .

  In the third invention, in particular, the first fluid pipes that are in contact with each other according to the first invention are provided with flat portions along the axial direction, and the respective flat portions are brought into contact with each other. When the second fluid flow path is designed to have the same area, the diameter of the outer pipe can be reduced. Alternatively, when the outer pipes are designed with the same diameter, the cross-sectional area of the second fluid channel can be enlarged, and the pressure loss in the second fluid channel can be reduced. Therefore, the weight of the heat exchanger can be reduced, the cost can be reduced, and the performance can be improved.

  According to a fourth aspect of the present invention, the leak detection tube according to any one of the first to third aspects is provided with a convex portion protruding toward the second fluid flow path along the axial direction thereof. It becomes easy and the manufacturing cost can be reduced. In addition, by providing a convex portion on the leak detection tube, the heat transfer area can be expanded, and the performance of the heat exchanger can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 is a circuit configuration diagram of a water heater equipped with a heat exchanger according to the first embodiment of the present invention.

  In FIG. 1, the hot water supply apparatus includes a refrigerant circuit A as a first fluid circuit and a water circuit B as a second fluid circuit. The refrigerant circuit A includes the compressor 1, the first fluid flow path 24 of the heat exchanger 2 in the present embodiment, the decompressor 3, the heat source side heat exchanger 4, and the like. On the other hand, the circuit B for water is comprised from the feed water pump 5, the 2nd fluid flow path 25 of the heat exchanger 2, the hot water supply tank 6, etc.

  Next, the operation of this hot water supply apparatus will be described. The refrigerant (for example, carbon dioxide gas) that is the first fluid compressed by the compressor 1 is in a high-temperature and high-pressure state, and passes through the first fluid channel 24 of the heat exchanger 2 to pass through the second fluid channel 25. Heat is dissipated and cooled to the flowing second fluid (for example, water). That is, the water sent from the bottom of the hot water supply tank 6 to the second fluid flow path 25 by the water supply pump 5 is heated by the refrigerant flowing through the first fluid flow path 24.

  Thereafter, the refrigerant is decompressed by the decompressor 3 to be in a low-temperature and low-pressure gas-liquid two-phase state. In the heat source side heat exchanger 4, the refrigerant takes heat from the surrounding air and enters a gas-liquid two-phase or gas state. Further, the refrigerant in the gas-liquid two-phase or gas state is again sucked into the compressor 1. By repeating such a cycle, the water flowing through the second fluid flow path 25 of the heat exchanger 2 becomes hot water, and can be used as a hot water heater by storing the hot water at the top of the hot water supply tank 6.

  Next, the detail of the heat exchanger 2 in this Embodiment is demonstrated using FIG. FIG. 2 is a schematic configuration diagram of the heat exchanger, and FIG. 3 is a cross-sectional view in a direction perpendicular to the axial direction of the double pipe of the heat exchanger.

  2 and 3, the heat exchanger 2 is formed of a double tube 21 that is spirally wound and includes a copper outer tube 23 and a copper inner tube 22 inserted into the copper outer tube 23. Yes.

  The inner pipe 22 includes two refrigerant pipes 26 as first fluid pipes, and a leak detection pipe 27 that has a leak detection groove 28 on the inner surface and covers the two refrigerant pipes 26. A first fluid channel 24 is formed inside the refrigerant tube 26, and a second fluid channel 25 is formed between the outside of the inner tube 22 and the inner wall of the outer tube 23.

  Both ends of the double pipe 21 are separated from each other by the branch portion 31 without the first fluid channel 24 and the second fluid channel 25 communicating with the outside. That is, the inner tube 22 is drawn to the outside of the outer tube 23. At both ends of the inner pipe 22, the two refrigerant pipes 26 and the leak detection pipe 27 are separated, and the leak detection groove 28 provided in the leak detection pipe 27 communicates with the outside. In addition, a merging portion 32 is provided at both ends of the two refrigerant pipes 26, and the first fluid flow paths 24 formed inside the two refrigerant pipes 26 are integrated without communicating with the outside. ing.

  33a and 33b are an inlet part and an outlet part of the first fluid channel 24, respectively, and 34a and 34b are an inlet part and an outlet part of the second fluid channel 25, respectively. The inlet portion 33a and the outlet portion 33b of the first fluid channel 24 are connected to the refrigerant circuit A in the hot water supply device, and the inlet portion 34a and the outlet portion 34b of the second fluid channel 25 are connected to the water circuit in the hot water device. By connecting to B, heat exchange can be performed between the first fluid (for example, carbon dioxide) and the second fluid (for example, water).

  The white arrow in the figure indicates the flow direction of the second fluid, and the solid line arrow indicates the flow direction of the first fluid. In the double pipe 21, the first fluid and the second fluid are opposed to each other. It is configured to exchange heat.

  A plurality of leak detection grooves 28 are formed on the inner surface of the leak detection pipe 27 along the axial direction of the leak detection pipe 27, and an air layer is formed in the leak detection groove 28. Thereby, the refrigerant or water leaking from the first fluid channel 24 or the second fluid channel 25 is leaked to the outside through the leak detection groove 28 without being mixed. In the present embodiment, the inner tube 22 is configured by inserting two refrigerant tubes 26 into one leak detection tube 27 having a substantially elliptical cross section.

  In the heat exchanger configured as described above, the following effects can be obtained.

  Compared to a conventional heat exchanger configured by using two inner pipes configured by inserting one refrigerant pipe into one leak detection pipe, two refrigerant pipes are provided in one leak detection pipe 27. By using one inner tube 22 configured by inserting 26, the amount of copper used can be reduced while maintaining the performance of the heat exchanger.

Therefore, according to this Embodiment, the weight of a heat exchanger can be reduced and cost reduction can be achieved. Furthermore, when the second fluid flow path 25 is designed to have the same area by reducing the cross-sectional area of the inner tube 22, the tube diameter of the outer tube 23 can be reduced, or the tube diameter of the outer tube 23 can be reduced. Are designed to be the same, the cross-sectional area of the second fluid channel 25 can be enlarged, and the pressure loss in the second fluid channel 25 can be reduced.

  As described above, in the present embodiment, the weight of the heat exchanger can be reduced, the cost can be reduced, and the performance can be improved.

(Embodiment 2)
FIG. 4 is a cross-sectional view of the double tube of the heat exchanger according to the second embodiment of the present invention. Note that the same parts as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 4, the double pipe 41 of the heat exchanger in the present embodiment is composed of an outer pipe 23 and an inner pipe 42 inserted into the outer pipe 23. Two refrigerant pipes 26 in which one fluid flow path 24 is formed, and a plurality of leakage detection grooves 48 are formed along the axial direction of the inner surface with an approximately eight-shaped section, and the two refrigerant pipes 26 are inserted. The second fluid flow path 45 is formed between the outer side of the inner pipe 42 and the inner wall of the outer pipe 23.

  An air layer is formed in the leak detection groove 48. In the present embodiment, the inner pipe 42 is configured by inserting two refrigerant pipes 26 into one leak detection pipe 47 having a substantially eight-shaped cross section. A recess 47 a is formed in the second fluid flow path 25 along the axial direction of the second fluid flow path 25.

  In the heat exchanger configured as described above, the following effects can be obtained.

  Compared to the conventional heat exchanger, by using one inner pipe 42 configured by inserting two refrigerant pipes 26 into one leakage detection pipe 47, the performance of the heat exchanger is maintained, The amount of copper used can be reduced. Therefore, in this embodiment, the weight of the heat exchanger can be reduced or the cost can be reduced. Furthermore, by providing the recess 47a in the leak detection pipe 47, the cross-sectional area of the inner pipe 42 is reduced, and when the second fluid flow path 45 is designed to have the same area, the pipe diameter of the outer pipe 23 can be reduced. Alternatively, when the outer pipe 23 is designed with the same diameter, the cross-sectional area of the second fluid channel 45 can be enlarged, and the pressure loss in the second fluid channel 45 can be reduced.

  As described above, according to the present embodiment, the weight of the heat exchanger can be reduced, the cost can be reduced, and the performance can be improved.

(Embodiment 3)
FIG. 5 is a cross-sectional view of a double tube of a heat exchanger according to the third embodiment of the present invention. In addition, about the same part as the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 5, the double pipe 51 of the heat exchanger in the present embodiment includes an outer pipe 23 and an inner pipe 52 inserted into the outer pipe 23, and the inner pipe 52 has a first inside. The two refrigerant pipes 56 in which the fluid flow path 54 is formed, and the leak detection pipe 57 that covers the two refrigerant pipes 56 and in which a plurality of leak detection grooves 58 are formed along the axial direction of the inner surface. In addition, a second fluid channel 55 is formed between the outside of the inner tube 52 and the inner wall of the outer tube 23. An air layer is formed in the leak detection groove 58.

In the present embodiment, the inner pipe 52 is configured by inserting two refrigerant pipes 56 into one leak detection pipe 57 having a substantially circular cross section. Further, as shown in FIG. 5, a flat portion 56a is provided on the outer side of each of the two refrigerant tubes 56 along the axial direction of the refrigerant tube 56, and the flat portions 56a are in surface contact with each other.

  In the heat exchanger configured as described above, the following effects can be obtained.

  Compared to the conventional heat exchanger, by using one inner pipe 52 configured by inserting two refrigerant pipes 56 into one leakage detection pipe 57, the performance of the heat exchanger is maintained, The amount of copper used can be reduced. Therefore, in the present embodiment, the weight of the heat exchanger can be reduced and the cost can be reduced. Furthermore, by providing a flat portion 56a along the axial direction of the refrigerant pipe 56 on the outside of each of the two refrigerant pipes 56 so as to be in surface contact with each other, the cross-sectional area of the inner pipe 52 is reduced. When the second fluid channel 55 is designed to have the same area, the diameter of the outer tube 23 can be reduced. Alternatively, when the outer pipe 23 is designed with the same diameter, the cross-sectional area of the second fluid channel 55 can be enlarged, and the pressure loss in the second fluid channel 55 can be reduced.

  As described above, according to the present embodiment, the weight of the heat exchanger can be reduced, the cost can be reduced, and the performance can be improved.

(Embodiment 4)
FIG. 6 is a cross-sectional view of a double tube of a heat exchanger in the fourth embodiment of the present invention. In addition, about the same part as the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 6, the double pipe 61 of the heat exchanger in the present embodiment includes an outer pipe 23 and an inner pipe 62 inserted into the outer pipe 23, and the inner pipe 62 has a first inside. The two refrigerant pipes 26 in which the fluid flow path 24 is formed, and a leak detection pipe 67 having a plurality of leak detection grooves 68 along the axial direction of the inner surface and covering the two refrigerant pipes 26 are configured.

  A second fluid flow path 65 is formed between the outer side of the inner pipe 62 and the inner side of the outer pipe 23, and an air layer is formed in the leakage detection groove 68.

  In the present embodiment, the inner pipe 62 includes two refrigerant pipes 26 inserted into one leak detection pipe 67, and the leak detection pipe 67 is connected to the second fluid flow path 65 along the axial direction. The two refrigerant pipes 26 and the leak detection pipe 67 are configured to be brought into close contact with each other by being deformed so as to be provided with a protruding portion 67a projecting.

  In the heat exchanger configured as described above, the following effects can be obtained.

  Compared to the conventional heat exchanger, by using one inner pipe 62 configured by inserting two refrigerant pipes 26 into one leakage detection pipe 67, the performance of the heat exchanger is maintained, The amount of copper used can be reduced. Therefore, in this embodiment, the weight of the heat exchanger can be reduced and the cost can be reduced.

  Furthermore, the inner pipe 62 is configured to be deformed so as to have a protruding portion 67a protruding with respect to the second fluid flow path 65, and the inner surfaces of the two refrigerant pipes 26 and the leak detection pipe 67 are brought into close contact with each other. Manufacturing is facilitated, and manufacturing costs can be reduced. In addition, by providing the protrusion 67a on the leak detection tube 67, the heat transfer area of the second fluid flow path 65 can be expanded, and the performance of the heat exchanger can be improved.

  In the above embodiment, the inner pipe is described as an example constituted by two refrigerant pipes and one leakage detection pipe, but three or more refrigerant pipes and one leakage detection pipe are described. You may comprise. Moreover, although the inner tube and the outer tube are made of copper, other materials may be used.

  The heat exchanger according to the present invention can reduce the weight, reduce the cost, and improve the performance by configuring the inner pipe with a plurality of refrigerant pipes and one leak detection pipe. However, the present invention can be widely applied to various refrigeration cycle apparatuses.

The circuit block diagram of the hot water supply apparatus carrying the heat exchanger in Embodiment 1 of this invention Schematic configuration diagram of the heat exchanger Cross section of double pipe of heat exchanger Sectional drawing of the double pipe of the heat exchanger in Embodiment 2 of this invention Sectional drawing of the double pipe of the heat exchanger in Embodiment 3 of this invention Sectional drawing of the double pipe of the heat exchanger in Embodiment 4 of this invention Cross section of a double pipe of a conventional heat exchanger

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Heat exchanger 3 Pressure reducer 4 Heat source side heat exchanger 5 Water supply pump 6 Hot water supply tank 21, 41, 51, 61 Double pipe 22, 42, 52, 62 Inner pipe 23 Outer pipe 24, 54 First fluid Flow path 25, 45, 55, 65 Second fluid flow path 26, 56 Refrigerant pipe (first fluid pipe)
27, 47, 57, 67 Leakage detection tube 28, 48, 58, 68 Leakage detection groove 31 Branching portion 32 Junction portion A Circuit for refrigerant (first fluid circuit)
B Water circuit (second fluid circuit)

Claims (4)

A double pipe comprising an outer pipe and an inner pipe inserted into the outer pipe, wherein the inner pipe has a plurality of first fluid pipes each having a first fluid flow path formed therein; and the plurality of first pipes. The second fluid flow path includes a single leakage detection tube that covers the fluid tube and includes a plurality of leakage detection grooves in the axial direction of the inner surface, and a second fluid flow path between the outer side of the inner tube and the inner wall of the outer tube. A heat exchanger characterized by being formed. The heat exchanger according to claim 1, wherein a concave portion is provided along an axial direction on an outer periphery of the leak detection tube. 2. The heat exchanger according to claim 1, wherein the first fluid pipes that are in contact with each other are provided with a flat portion along the axial direction, and the respective flat portions are brought into contact with each other. The heat exchanger according to any one of claims 1 to 3, wherein the leak detection tube includes a convex portion protruding toward the second fluid flow path along the axial direction thereof.

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