JP6574630B2 - Double tube heat exchanger - Google Patents

Description

  The present invention relates to a double-tube heat exchanger, and more particularly to a double-tube heat exchanger that includes an outer tube and an inner tube that is disposed in the outer tube at intervals.

  In this specification, the term “capacitor” includes a subcool condenser having a condensing part and a supercooling part in addition to a normal condenser.

  Conventionally, as a refrigeration cycle used in a car air conditioner, a compressor, a condenser having a condensing part and a supercooling part, an evaporator, an expansion valve as a decompressor, a gas-liquid separator, and a condenser and an evaporator, and An apparatus including an intermediate heat exchanger for exchanging heat between a high-temperature refrigerant coming out of a condenser supercooling section and a low-temperature refrigerant coming out of an evaporator has been proposed (see Patent Document 1). In the refrigeration cycle described in Patent Document 1, the refrigerant supercooled in the condenser supercooling section is further cooled by the low-temperature and low-pressure refrigerant that has come out of the evaporator in the intermediate heat exchanger, whereby the cooling performance of the evaporator is improved. It can be improved.

  The intermediate heat exchanger used in the refrigeration cycle described in Patent Literature 1 includes an outer tube and an inner tube arranged at intervals in the outer tube, and deforms the tube wall on the outer peripheral surface of the inner tube. As a result, a groove extending in the length direction of the inner pipe is formed, and the gap between the outer pipe and the inner pipe becomes the first refrigerant flow path through which the high-temperature refrigerant coming out of the condenser flows, and the inside of the inner pipe comes out of the evaporator. It consists of a double-pipe heat exchanger that is a second refrigerant flow path through which a low-temperature refrigerant flows.

  However, in the case of the double tube heat exchanger used in the intermediate heat exchanger described in Patent Document 1, the heat transfer area between the first refrigerant flow path and the second refrigerant flow path is reduced, and heat exchange is performed. There is a problem of insufficient performance. In order to solve this problem, it is necessary to increase the length of the double-pipe heat exchanger. In this case, however, there is a problem that the installation space becomes large.

  Accordingly, the present applicant has disclosed a double-pipe heat exchanger capable of improving the heat exchange performance between the refrigerant flowing through the first refrigerant flow path and the refrigerant flowing through the second refrigerant flow path, thereby reducing the overall length. Is composed of a wave crest portion, a wave bottom portion, and a connecting portion that connects the wave crest portion and the wave bottom portion along the inner peripheral surface of the inner tube, and the wave crest portion and the wave bottom portion are refrigerant in the second refrigerant flow path. Corrugated fins facing the flow direction are arranged, the wave crests of the fins are joined to the inner peripheral surface of the inner tube, and a gap is formed in the radially inner portion of the inner tube with respect to the fins in the inner tube. In addition, a double-tube heat exchanger has been proposed in which a drift member made of a torsion plate and drifting the refrigerant flowing in the gap to the fin side is arranged (see Patent Document 2).

  However, in the double-pipe heat exchanger described in Patent Document 2, a drift member is required, and the number of dedicated components for the refrigeration cycle using the double-pipe heat exchanger as an intermediate heat exchanger increases.

JP 2006-162241 A JP 2014-224670 A

  An object of the present invention is to provide a double-tube heat exchanger that solves the above-described problems and can reduce the number of dedicated components of the refrigeration cycle that uses the double-tube heat exchanger as an intermediate heat exchanger. It is in.

  In order to achieve the above object, the present invention comprises the following aspects.

1) An outer pipe and an inner pipe arranged at intervals in the outer pipe, and a gap between the outer pipe and the inner pipe becomes the first refrigerant flow path, and the inner pipe has the second refrigerant flow path. A wave crest portion, a wave bottom portion, and a connecting portion that connects the wave crest portion and the wave bottom portion along the inner peripheral surface of the inner pipe, and the wave crest portion and the wave bottom portion flow in the second refrigerant flow path. A double-tube heat exchanger in which corrugated fins facing in a direction are arranged, a wave crest portion of the fin is joined to the inner peripheral surface of the inner tube, and a refrigerant passage hole is formed in a coupling portion of the fin,
A void is formed in the radially inner portion of the inner tube with respect to the fin in the inner tube, and a desiccant container made of a material having air permeability and liquid permeability and containing a desiccant is disposed in the void. Double-tube heat exchanger.

  2) The double-pipe heat exchanger according to 1) above, wherein the desiccant container is a bag made of non-woven fabric and closed around.

  3) The double pipe according to 1) above, wherein the desiccant container comprises a cylindrical body made of a mesh and opened at both ends, and a closing member made of the mesh and closing both ends of the cylindrical body. Type heat exchanger.

4) A compressor having a compressor, a condenser and a supercooling unit, an evaporator, a decompressor, a gas-liquid separator, a high-temperature refrigerant and an evaporator disposed between the condenser and the evaporator and coming out of the condenser supercooling unit A refrigeration cycle comprising an intermediate heat exchanger for exchanging heat with a low-temperature refrigerant coming out of, and a desiccant for removing moisture from the refrigerant,
The double tube heat exchanger according to any one of the above 1) to 3) is used as an intermediate heat exchanger, and the desiccant in the desiccant container becomes a desiccant that removes moisture from the refrigerant. Refrigeration cycle.

  According to the double-pipe heat exchanger of 1) to 3) above, a void is formed in the radially inner portion of the inner tube with respect to the fin in the inner tube, and air permeability and liquid permeability are formed in the void. In addition to being able to remove moisture from the refrigerant flowing in the inner tube by the desiccant in the desiccant container, the following effects are obtained. Play. That is, it comprises a wave crest portion, a wave bottom portion, and a connecting portion that connects the wave crest portion and the wave bottom portion along the inner peripheral surface of the inner tube, and the wave crest portion and the wave bottom portion indicate the refrigerant flow direction in the second refrigerant flow path. When the corrugated fins facing each other are arranged and the crest portion of the fin is joined to the inner peripheral surface of the inner tube, the passage resistance in the gap portion formed in the radially inner portion of the inner tube than the fin in the inner tube is Since it becomes smaller than the passage resistance in the portion where the fin is present, the refrigerant easily flows through the gap portion of the second refrigerant flow channel in the inner pipe, and flows through the first refrigerant flow channel by providing the fin. There is a possibility that the effect of improving the heat exchange efficiency between the refrigerant and the refrigerant flowing through the second refrigerant flow path may be reduced. However, when a desiccant container is disposed in the gap, the desiccant container becomes a resistance, and a large amount of refrigerant flows through the portion of the second refrigerant channel in the inner pipe where fins exist. It is possible to suppress a decrease in the effect of improving the heat exchange efficiency between the refrigerant flowing through the first refrigerant flow path and the refrigerant flowing through the second refrigerant flow path. Therefore, unlike the double tube heat exchanger described in Patent Document 2, a drift member is not required, and the desiccant is essential for a refrigeration cycle in which the double tube heat exchanger is used as an intermediate heat exchanger. Since it is a component, the number of dedicated components for the refrigeration cycle can be reduced.

  According to the refrigeration cycle of 4), as described above, the number of dedicated parts for the refrigeration cycle can be reduced. In addition, the desiccant that removes moisture from the refrigerant is usually placed in the gas-liquid separator of the refrigeration cycle. In this case, the gas-liquid separator is enlarged, but the gas-liquid separator is prevented from being enlarged. can do.

It is the front view which abbreviate | omitted the intermediate part of the length direction which shows the whole structure of the double tube | pipe type heat exchanger by this invention, and notched one part. It is an AA line expanded sectional view of FIG. It is a perspective view which shows partially the structure of the outer tube | pipe of the double tube | pipe type heat exchanger of FIG. 1, an inner tube | pipe, and a desiccant container. It is a figure which shows the refrigerating cycle which used the double tube | pipe type heat exchanger of FIG. 1 as an intermediate | middle heat exchanger. It is a figure equivalent to FIG. 2 which shows the modification of the desiccant container used for the double pipe type heat exchanger by this invention. It is a figure equivalent to FIG. 3 which shows the modification of the desiccant container used for the double tube | pipe type heat exchanger by this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  In addition, the same code | symbol is attached | subjected to the same part and the same thing through all drawings, and the overlapping description is abbreviate | omitted.

  In the following description, the term “aluminum” includes aluminum alloys in addition to pure aluminum.

  FIG. 1 shows the overall configuration of a double-pipe heat exchanger according to the present invention, and FIGS. 2 and 3 show the configuration of the main part thereof. FIG. 4 shows a refrigeration cycle using the double-pipe heat exchanger of FIG. 1 as an intermediate heat exchanger.

  1 to 3, the double-pipe heat exchanger (1) is concentrically arranged at intervals in the outer tube (2) made of an aluminum extruded section having a circular cross section and the outer tube (2). The inner pipe (3) made of extruded aluminum with a circular cross section is provided, and the gap between the outer pipe (2) and the inner pipe (3) becomes the first refrigerant channel (4), and the inner pipe (3) The inside is the second refrigerant flow path (5). Both end portions of the inner pipe (3) protrude outward from both end portions of the outer pipe (2), and pipe joint members (6) are joined to both protruding end portions, respectively.

  Expanded portions (7) and (8) are formed at portions near both ends of the outer tube (2) so as to communicate with the first refrigerant flow path (4), respectively. A refrigerant inlet (9) is formed on the tube wall of one expanded portion (7) in the outer tube (2), and a refrigerant outlet (not shown) is formed on the tube wall of the other expanded portion (8). Yes. One end of an aluminum high-pressure refrigerant inflow pipe (11) leading to the first refrigerant flow path (4) is inserted into the refrigerant inlet (9) and brazed to the expanded pipe (7). One end of an aluminum high-pressure refrigerant outflow pipe (12) communicating with the first refrigerant flow path (4) is inserted into the refrigerant outlet and brazed to the expanded pipe (8). Pipe joint members (13) are joined to the other ends of the high-pressure refrigerant inflow pipe (11) and the high-pressure refrigerant outflow pipe (12), respectively. The expanded pipe part (7) to which the high-pressure refrigerant inflow pipe (11) is brazed becomes a diversion part for diverting the refrigerant sent from the high-pressure refrigerant inflow pipe (11) over the entire circumference of the first refrigerant flow path (4). The expanded pipe portion (8) to which the high-pressure refrigerant outflow pipe (12) is brazed serves as a confluence section that joins the refrigerant flowing through the first refrigerant flow path (4) and sends it to the high-pressure refrigerant outflow pipe (12). Yes. In addition, a contracted tube portion (14) is formed in the outer portion of the outer tube (2) in the length direction from both expanded portions (7) and (8), and the contracted tube portion (14) is connected to the inner tube (3 ), Whereby the outer ends of both expanded portions (7) and (8), that is, both ends of the first refrigerant flow path (4) are closed. The contraction pipe part (14) is provided with an outer pipe (2) in which a pipe expansion part longer than both of the pipe expansion parts (7) and (8) is formed near the both ends. After inserting the inner pipe (3), by applying a force from the outer peripheral side to the outer part in the length direction of the outer pipe (2) in the lengthwise direction than the parts to be the both expanded parts (7) (8), It is formed.

  The corrugated fin made of aluminum along the inner peripheral surface of the inner pipe (3) in the portion where the first refrigerant flow path (4) exists, that is, the portion between the two contraction pipe portions (14) of the outer pipe (2). (15) is arranged. The fin (15) is formed using an aluminum brazing sheet having a brazing filler metal layer on both sides, and the wave crest (15a) extending in the refrigerant flow direction in the second refrigerant flow path (5), the second The wave bottom part (15b) extending in the refrigerant flow direction in the refrigerant flow path (5) and the connecting part (15c) connecting the wave crest part (15a) and the wave bottom part (15b), the wave crest part (15a) The pipe (3) is brazed (joined) to the inner peripheral surface. A plurality of louvers (16) extending in the direction from the wave crest (15a) to the wave bottom (15b) (the radial direction of the inner pipe (3)) are connected to the connecting portion (15c) of the fin (15). A plurality of coolant passage holes (not shown) are formed in the connecting portion (15c) by providing an interval in the coolant flow direction in the passage (5). All the louvers (16) provided in the connecting portion (15c) of the fin (15) are inclined in the same direction with respect to the refrigerant flow direction in the second refrigerant flow path (5). The fins (15) are rounded into a cylindrical shape after the connecting portions (15c) are formed in a straight line by a normal manufacturing method, and are arranged in the inner tube (3) in this state.

  A gap (17) is formed in the radially inner portion of the inner pipe (3) from the wave bottom (15b) of the fin (15) in the second refrigerant flow path (5) in the inner pipe (3), A desiccant bag (18) (desiccant container) made of a material having air permeability and liquid permeability and containing a desiccant (19) is disposed in the gap (17). The desiccant bag (18) is a bag made of non-woven fabric and closed around the periphery.

  A plurality of protrusions (3a) extending in the length direction are integrally provided on the outer peripheral surface of the inner tube (3) at intervals in the circumferential direction. Although not shown, the portion corresponding to the contracted tube portion (14) in the ridge (3a) is formed when the contracted tube portion (14) is formed in the expanded tube portions (7) and (8) of the outer tube (2). The gap between the inner peripheral surface of the contracted tube portion (14) and the adjacent crushed ridges (3a) in the inner tube (3) is filled with a brazing material. Note that the protrusion (3a) of the inner pipe (3) is not necessarily required.

  Although illustration is omitted, the outer tube (2) and the inner tube (3) may be entirely straight or bent at at least one location.

  FIG. 4 shows a refrigeration cycle using the above-described double-pipe heat exchanger (1) as an intermediate heat exchanger.

  In FIG. 4, the refrigeration cycle uses, for example, a chlorofluorocarbon refrigerant as a refrigerant, and includes a compressor (20), a condensing unit (22), a liquid receiver (23) as a gas-liquid separator, and a supercooling unit ( 24), the condenser (21), the evaporator (25), the expansion valve (26) as a pressure reducer, and the refrigerant coming out of the condenser (20) and the refrigerant coming out of the evaporator (25). And a double-pipe heat exchanger (1) as an intermediate heat exchanger, and the desiccant (19) in the desiccant bag (18) removes moisture from the refrigerant circulating in the refrigeration cycle. A desiccant is not disposed in the liquid receiver (23).

  A pipe extending from the supercooling section (24) of the condenser (20) is connected to the high-pressure refrigerant inflow pipe (11) connected to the outer pipe (2) of the double-pipe heat exchanger (1). A pipe extending to the expansion valve (26) is connected to the high-pressure refrigerant outflow pipe (12) connected to 2). In addition, a pipe extending from the evaporator (25) is connected to the end of the inner pipe (3) of the double pipe heat exchanger (1) on the side of the high-pressure refrigerant outflow pipe (12), and also in the inner pipe (3). A pipe extending to the compressor (20) is connected to an end of the high-pressure refrigerant inflow pipe (11) side. The refrigeration cycle is mounted on a vehicle such as an automobile as a car air conditioner.

  During the operation of the refrigeration cycle, the high-temperature and high-pressure gas-liquid mixed phase refrigerant compressed by the compressor (20) is cooled and condensed by the condenser (22) of the condenser (21), and then the receiver (23) It flows into the interior and is separated into two phases of gas and liquid, and then flows into the supercooling section (24) to be supercooled. The supercooled liquid phase refrigerant flows through the high-pressure refrigerant inflow pipe (11) into the expanded pipe (7) of the outer pipe (2) of the double-pipe heat exchanger (1). ) Through the first refrigerant flow path (4). The liquid phase refrigerant that has flowed into the expanded pipe portion (7) is diverted over the entire circumference of the first refrigerant flow path (4) by the action of the expanded pipe portion (7). On the other hand, the gas-phase refrigerant coming out of the evaporator (25) flows into the second refrigerant flow path (5) of the double pipe heat exchanger (1). Then, while the liquid-phase refrigerant flows in the first refrigerant channel (4), it is further cooled by the relatively low temperature gas-phase refrigerant flowing in the second refrigerant channel (5).

  At this time, the refrigerant flowing into the second refrigerant channel (5) contacts the desiccant (19) in the desiccant bag (18), and the moisture contained in the refrigerant is removed by the desiccant (19). . Further, since the desiccant bag (18) is disposed in the gap (17) in the second refrigerant channel (5), the desiccant bag (18) becomes a resistance, and the second refrigerant channel (5) A large amount of refrigerant also flows through the portion where the fins (15) are present. Moreover, the refrigerant passes through the second refrigerant flow path (5) in the inner pipe (3) by the action of the louver (16) and the refrigerant passage hole provided in the connecting part (15c) of the fin (15). Since it flows while turning around the axis of (3), the refrigerant flowing in the second refrigerant channel (5) is effectively agitated. Therefore, the heat exchange efficiency between the refrigerant flowing through the first refrigerant channel (4) and the refrigerant flowing through the second refrigerant channel (5) is effectively improved.

  5 and 6 show a modification of the desiccant container used in the above-described double tube heat exchanger (1).

  5 and 6, a desiccant container made of a material having air permeability and liquid permeability and having a desiccant (19) placed therein and disposed in the gap (17) of the second refrigerant flow path (5). (30) is a cylindrical body (31) made of a metal or synthetic resin mesh and having both ends open, and a closing member made of a mesh and closing both ends of the cylindrical body (31). (32). The cylindrical body (31) and the closing member (32) function as a filter.

  The double pipe heat exchanger according to the present invention is disposed between a compressor, a condenser having a condensing part and a supercooling part, an evaporator, an expansion valve as a decompressor, a gas-liquid separator, and the condenser and the evaporator, In a refrigeration cycle that constitutes a car air conditioner having an intermediate heat exchanger that exchanges heat between the high-temperature refrigerant that has come out of the condenser supercooling section and the low-temperature refrigerant that has come out of the evaporator, it is suitable as an intermediate heat exchanger Used.

(1): Double tube heat exchanger
(2): Outer pipe
(3): Inner pipe
(4): First refrigerant flow path
(5): Second refrigerant flow path
(15): Fin
(15a): Wave peak
(15b): Wave bottom
(15c): Connection part
(17): Air gap
(18): Desiccant bag (desiccant container)
(19): Desiccant
(20): Compressor
(21): Capacitor
(22): Condensing part
(23): Liquid receiver (gas-liquid separator)
(24): Supercooling section
(25): Evaporator
(26): Expansion valve (pressure reducer)
(30): Desiccant container
(31): Tubular body
(32); Closing member

Claims (4)

An outer pipe and an inner pipe arranged at intervals in the outer pipe are provided, and a gap between the outer pipe and the inner pipe serves as a first refrigerant flow path, and the inner pipe serves as a second refrigerant flow path. A wave crest portion, a wave bottom portion, and a connecting portion that connects the wave crest portion and the wave bottom portion along the inner peripheral surface of the inner tube, and the wave crest portion and the wave bottom portion indicate the refrigerant flow direction in the second refrigerant flow path. A double-tube heat exchanger in which corrugated fins facing each other are arranged, a wave crest portion of the fin is joined to the inner peripheral surface of the inner tube, and a refrigerant passage hole is formed in a coupling portion of the fin,
A void is formed in the radially inner portion of the inner tube with respect to the fin in the inner tube, and a desiccant container made of a material having air permeability and liquid permeability and containing a desiccant is disposed in the void. Double-tube heat exchanger. The double-pipe heat exchanger according to claim 1, wherein the desiccant container is formed of a nonwoven fabric and has a bag shape with a closed periphery. The double-pipe heat according to claim 1, wherein the desiccant container comprises a cylindrical body made of a mesh and having both ends opened, and a closing member made of the mesh and closing both ends of the cylindrical body. Exchanger. Compressor, condenser having condenser and supercooling part, evaporator, decompressor, gas-liquid separator, high temperature refrigerant and evaporator coming from condenser supercooling part, placed between condenser and evaporator An intermediate heat exchanger that exchanges heat with a low-temperature refrigerant, and a refrigeration cycle that includes a desiccant that removes moisture from the refrigerant,
The double-pipe heat exchanger according to any one of claims 1 to 3 is used as an intermediate heat exchanger, and the desiccant in the desiccant container is a desiccant that removes moisture from the refrigerant. Refrigeration cycle.

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