JP2014224670A - Double-pipe heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-pipe heat exchanger capable of further increasing a heat transfer area between a first refrigerant flow path and a second refrigerant flow path.SOLUTION: A double-pipe heat exchanger comprises: an outer pipe 2; and an inner pipe 3 arranged in the outer pipe 2 to be distanced from the outer pipe 2, and a gap between the outer pipe 2 and the inner pipe 3 serves as a first refrigerant flow path 4 and an interior of the inner pipe 3 serves as a second refrigerant flow path 5. Along an inner circumferential surface of the inner pipe 3, a corrugated fin 15 including wave crest portions 15a; wave bottom portions 15b; and coupling portions 15c each coupling one wave crest portion 15a to one wave bottom portion 15b, with the wave crest portions 15a and the wave bottom portions 15b oriented in a refrigerant flow direction in the second refrigerant flow path 5, is arranged. The wave crest portions 15a of the fin 15 are joined to the inner circumferential surface of the inner pipe 3. Refrigerant passing holes are formed by providing a plurality of louvers 16 in the coupling portions 15c of the fin 15. All the louvers 16 provided in the coupling portions 15c are inclined in the same direction with respect to the refrigerant flow direction in the second refrigerant flow path 5.

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 view of this, the present applicant firstly arranged a space between the outer pipe and the outer pipe as a double pipe heat exchanger having an increased heat transfer area between the first refrigerant flow path and the second refrigerant flow path. And the inner pipe disposed in the inner pipe has a gap between the outer pipe and the inner pipe serving as the first refrigerant flow path and the inner pipe serving as the second refrigerant flow path. In addition, a plurality of internal fins protruding inward in the radial direction and extending in the length direction are provided at intervals in the circumferential direction, and a plurality of protrusions protruding in the radial direction and extending in the length direction are provided on the outer peripheral surface of the inner tube. A double-tube heat exchanger has been proposed in which a plurality of ridges are provided at intervals in the circumferential direction, and the fin height of the internal fins is higher than the protrusion height of the ridges (see Patent Document 2).

  However, recently, there has been a demand for a double-pipe heat exchanger that can improve the heat exchange efficiency between the refrigerant flowing through the first refrigerant flow path and the refrigerant flowing through the second refrigerant flow path and shorten the overall length. It has been.

JP 2006-162241 A JP 2009-162395 A

  The object of the present invention is to meet the above requirement and further increase the heat transfer area between the first refrigerant flow path and the second refrigerant flow path as compared with the double pipe heat exchanger described in Patent Document 2. An object of the present invention is to provide a double tube heat exchanger.

  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 double pipe heat exchanger,
Along the inner peripheral surface of the inner tube, the wave crest portion, the wave bottom portion, and a connecting portion that connects the wave crest portion and the wave bottom portion are formed, and the wave crest portion and the wave bottom portion face the refrigerant flow direction in the second refrigerant flow path. A double-tube heat exchanger in which corrugated fins are arranged, the wave crests of the fins are joined to the inner peripheral surface of the inner tube, and a refrigerant passage hole is formed in the connecting portion of the fins.

  2) A plurality of louvers extending in the direction from the wave crest portion to the wave bottom portion are provided at intervals in the refrigerant flow direction in the second refrigerant flow path at the fin connection portion. The double pipe heat exchanger according to 1) above, wherein a passage hole is formed.

  3) The double-pipe heat exchanger according to 2) above, wherein all louvers provided in the connecting portion are inclined in the same direction with respect to the refrigerant flow direction in the second refrigerant flow path.

  4) A gap is formed in the radially inner portion of the inner pipe with respect to the fin in the inner pipe, and a drift member for drifting the refrigerant flowing in the gap to the fin side is disposed in the gap 1) ~ Double pipe heat exchanger according to any one of 3).

  5) The double pipe heat exchanger according to 4) above, wherein the drift member is a twisted plate.

  6) A plurality of spiral grooves recessed outward are formed on the inner peripheral surface of the inner tube by deforming the peripheral wall of the inner tube, and the twist direction of the torsion plate and the twist direction of the spiral groove The double-tube heat exchanger according to 5) above, wherein and are opposite directions.

  7) The double pipe heat exchanger according to 4) above, wherein the drift member is a cylindrical body having a spiral groove formed on the outer peripheral surface.

  8) The double-pipe heat exchanger according to 7) above, wherein the columnar body is formed of a cylinder with both ends closed, and the circumferential wall of the cylinder is deformed to form a spiral groove.

  9) On the inner peripheral surface of the inner tube, a plurality of spiral concave grooves recessed outward are formed by deforming the peripheral wall of the inner tube, and the spiral shape of the outer peripheral surface of the cylindrical body that becomes the drift member 7. The double pipe heat exchanger according to the above 7) or 8), wherein the twist direction of the concave groove and the twist direction of the spiral concave groove on the inner peripheral surface of the inner pipe are opposite to each other.

  10) The drift member is composed of a corrugated plate arranged so as to cross the gap in the cross section, and the corrugated plate is composed of a wave crest portion, a wave bottom portion, and a connecting portion connecting the wave crest portion and the wave bottom portion, and the wave crest portion and 4. The double-pipe heat exchanger according to 4) above, wherein the wave bottom portion faces the refrigerant flow direction in the second refrigerant flow path.

  11) A closing member for closing both end openings of the first refrigerant flow path is disposed at both ends of the outer pipe, and the closing member is fitted from the outside to the portions near both ends of the outer pipe and is placed on the outer pipe outer peripheral surface. The large cylindrical portion brazed, the small cylindrical portion that is fitted on the outer tube of the inner tube near the both ends of the outer tube and brazed to the outer peripheral surface of the inner tube, and the length direction of the outer tube in the large cylindrical portion The above 1) comprising a closed portion that connects an end portion on the opposite side to the central portion side and an end portion on the central portion side in the longitudinal direction of the inner tube in the small cylindrical portion and closes both end openings of the first refrigerant flow path. To 10). The double-pipe heat exchanger according to any one of?

  12) The above-mentioned 11), wherein the closing member is formed using a brazing sheet having a brazing material layer on at least one side so that the inner peripheral surfaces of the large cylindrical portion and the small cylindrical portion are covered with the brazing material layer. Double pipe heat exchanger.

  According to the double-pipe heat exchanger of 1) to 12) above, the wave top part, the wave bottom part, and the connecting part that connects the wave top part and the wave bottom part along the inner peripheral surface of the inner pipe, Since the corrugated fins having the top portion and the wave bottom portion facing the refrigerant flow direction in the second refrigerant flow path are disposed, and the wave crest portion of the fin is joined to the inner peripheral surface of the inner pipe, the first refrigerant flow path and the second refrigerant The heat transfer area between the flow paths can be increased. In addition, since the refrigerant passage hole is formed in the fin connection portion, the refrigerant flowing in the second refrigerant flow path is agitated by the action of the refrigerant passage hole formed in the fin connection portion. Therefore, the heat exchange efficiency between the refrigerant flowing through the first refrigerant flow path and the refrigerant flowing through the second refrigerant flow path is improved, and as a result, the overall length of the double-pipe heat exchanger can be shortened. Become.

  According to the double tube heat exchanger of 2) above, the refrigerant passage hole can be formed relatively easily in the connecting portion of the fin.

  According to the double pipe heat exchanger of 3) above, in the second refrigerant flow path in the inner pipe, a refrigerant flow that flows in one direction around the axis of the inner pipe is generated and flows in the second refrigerant flow path. The refrigerant is effectively agitated.

  According to the double tube heat exchanger of 4), the following effects are obtained. That is, as in the double-tube heat exchanger of 1) above, the wave crest portion, the wave bottom portion, and the 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. When the corrugated fins whose wave bottoms face the refrigerant flow direction in the second refrigerant flow path are arranged and the wave crests of the fins are joined to the inner peripheral surface of the inner pipe, the diameter of the inner pipe is larger than the fin in the inner pipe A void is formed in the inner portion in the direction. In this case, the passage resistance in the gap portion in the second refrigerant flow path in the inner pipe is smaller than the passage resistance in the portion where the fins are present, so that the refrigerant is the second refrigerant flow path in the inner pipe. There is a possibility that 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 due to the provision of the fins tends to flow through the gap portion. However, as in the double pipe heat exchanger of 4) above, the refrigerant flowing in the gap is biased to the fin side in the gap formed in the radially inner portion of the inner pipe with respect to the fin in the inner pipe. When the drift member is arranged, a large amount of refrigerant flows through the portion of the second refrigerant channel in the inner pipe where the fins exist, and the refrigerant flows through the first refrigerant channel and the second refrigerant channel. It is possible to suppress a decrease in the effect of improving the efficiency of heat exchange with the refrigerant.

  According to the double pipe heat exchanger of 5) above, the refrigerant flows while turning around the second refrigerant flow path in the inner pipe around the axis of the inner pipe, so that the refrigerant flowing in the second refrigerant flow path Are effectively stirred, and the heat exchange efficiency between the refrigerant flowing through the first refrigerant flow path and the refrigerant flowing through the second refrigerant flow path is effectively improved.

  According to the double pipe heat exchanger of 6), the refrigerant flowing in the second refrigerant flow path is more effectively agitated.

  According to the double pipe heat exchanger of the above 7), the refrigerant flows while turning around the second refrigerant flow path in the inner pipe around the axis of the inner pipe, so that the refrigerant flowing in the second refrigerant flow path Are effectively stirred, and the heat exchange efficiency between the refrigerant flowing through the first refrigerant flow path and the refrigerant flowing through the second refrigerant flow path is effectively improved.

  According to the double pipe heat exchanger of 8) above, an increase in the overall weight can be suppressed.

  According to the double pipe heat exchanger of 9), the refrigerant flowing in the second refrigerant flow path is more effectively agitated.

  According to the double pipe heat exchanger of the above 11), the fin is formed by using a brazing sheet provided with a brazing material layer on both sides, and the closing member has a brazing material layer on at least one side. By using a brazing sheet, the inner peripheral surfaces of the large cylindrical portion and the small cylindrical portion are covered with the brazing material layer, so that the wave crest portion of the fin, the inner peripheral surface of the inner tube, and the closing member It is possible to braze the inner peripheral surface of the large cylindrical portion and the outer peripheral surface of the outer tube and the inner peripheral surface of the small cylindrical portion and the outer peripheral surface of the inner tube at the same time. It will be easy.

It is the vertical longitudinal cross-sectional 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. 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 and inner tube | pipe of the double tube | pipe type heat exchanger of FIG. It is a longitudinal cross-sectional view which expands and shows the connection part of the fin arrange | positioned at the 2nd refrigerant | coolant flow path in the inner tube | pipe of the double pipe | tube type heat exchanger of FIG. It is a perspective view which shows partially the twist plate arrange | positioned in the 2nd refrigerant | coolant flow path in the inner tube | pipe of the double tube | pipe type heat exchanger of FIG. 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 2nd Embodiment of the double tube | pipe type heat exchanger by this invention. It is a figure equivalent to FIG. 3 which shows 2nd Embodiment of the double tube | pipe type heat exchanger by this invention. It is a figure equivalent to FIG. 3 which shows 3rd Embodiment of the double-pipe heat exchanger by this invention. It is a figure equivalent to FIG. 2 which shows 4th Embodiment of the double pipe | tube type heat exchanger by this invention. It is a figure equivalent to a part of Drawing 1 showing a 5th embodiment of a double tube type heat exchanger by this invention. It is a perspective view which shows the structure of a part of double pipe type heat exchanger of FIG. It is a figure equivalent to a part of Drawing 1 showing a 6th embodiment of a double tube type heat exchanger by this invention.

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

  In the drawings, the same parts and the same parts are denoted by the same reference numerals.

  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, FIGS. 2 to 5 show the configuration of the main part thereof, and FIG. The refrigeration cycle used as a container is shown.

  1 to 3, the double-pipe heat exchanger (1) is inserted into the outer tube (2) made of aluminum extruded section having a circular cross section and concentrically with a space in 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 It consists of a wave bottom (15b) extending in the refrigerant flow direction in the refrigerant flow path (5) and a connecting portion (15c) connecting the wave crest (15a) and the wave bottom (15b), and the wave crest (15a) is an inner tube. (3) It is brazed (joined) to the inner peripheral surface. As shown in FIG. 4, the connecting portion (15c) of the fin (15) has a plurality of louvers (in the radial direction of the inner tube (3)) extending from the wave crest (15a) to the wave bottom (15b) ( 16) are provided at intervals in the refrigerant flow direction in the second refrigerant flow path (5), whereby a plurality of refrigerant passage holes (17) are formed in the connecting portion (15c). 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 (18) 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). In the gap (18), an aluminum twist plate (19) (a drift member) that causes the refrigerant flowing in the gap (18) to drift toward the fin (15) is disposed. As shown in FIG. 5, the torsion plate (19) is obtained by twisting a belt-like plate around a center line passing through the center in the width direction and extending in the length direction. The twist plate (19) may be brazed to the wave bottom (15b) of the fin (15).

  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 not shown, the outer tube (2) and the inner tube (3) may be entirely straight or bent at at least one location.

  FIG. 6 shows a refrigeration cycle using the above-described double-tube heat exchanger (1) as an intermediate heat exchanger.

  In FIG. 6, 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. 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 that has come out of the evaporator (25) flows into the second refrigerant channel (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 that has flowed into the second refrigerant flow path (5) is moved to the central side in the radial direction where the gap (18) in the second refrigerant flow path (5) is formed by the action of the twist plate (19). A large amount of gas flows from the portion to the radially outer peripheral portion where the fins (15) are present, and flows uniformly throughout the second refrigerant flow path (5). 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 (17) provided in the connecting portion (15c) of the fin (15). Since it flows while turning around the axis of the inner pipe (3), the refrigerant flowing in the second refrigerant flow path (5) is effectively stirred. 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.

  7 and 8 show a second embodiment of the double-pipe heat exchanger according to the present invention.

  In the double-tube heat exchanger (30) shown in FIGS. 7 and 8, a plurality of spiral grooves (31) recessed outward are formed on the inner peripheral surface of the inner tube (3). ) To deform the peripheral wall. The twist direction of the spiral groove (31) is opposite to the twist direction of the twist plate (19). In addition, the outer circumferential surface of the inner tube (3) is not provided with a ridge (3a), and the inner wall (3) is deformed to form a spiral groove (31). A spiral ridge (32) is provided on the outer peripheral surface of the tube (3).

  Although not shown, the portion corresponding to the contracted tube portion (14) in the spiral ridge (32) forms the contracted tube portion (14) in the expanded tube portions (7) and (8) of the outer tube (2). In this case, the gap between the inner peripheral surface of the contracted tube portion (14) and the adjacent crushed spiral ridges (32) in the inner tube (3) is filled with a brazing material.

  Other configurations are the same as those of the double-tube heat exchanger (1) of the first embodiment shown in FIGS.

  FIG. 9 shows a third embodiment of the double-pipe heat exchanger according to the present invention.

  In the double-pipe heat exchanger (35) shown in FIG. 9, the inner pipe (3) is located more than the wave bottom (15b) of the fin (15) in the second refrigerant flow path (5) in the inner pipe (3). An aluminum columnar body (36) (a drift member) having a spiral groove (37) formed on the outer peripheral surface is disposed in the gap (18) formed in the radially inner portion. Although not shown in detail, the columnar body (36) is formed of a cylinder closed at both ends, and the circumferential wall of the cylinder is deformed to form a spiral groove (37). The cylindrical body (36) may be brazed to the wave bottom (15b) of the fin (15).

  Other configurations are the same as those of the double-tube heat exchanger (1) of the first embodiment shown in FIGS.

  FIG. 10 shows a fourth embodiment of the double-pipe heat exchanger according to the present invention.

  In the double-pipe heat exchanger (40) shown in FIG. 10, the inner pipe (3) is located more than the wave bottom (15b) of the fin (15) in the second refrigerant flow path (5) in the inner pipe (3). An aluminum corrugated plate (41) (a drift member) is disposed in the gap (18) formed in the radially inner portion so as to cross the gap (18) in the cross section. The corrugated plate (41) includes a wave crest (41a) extending in the refrigerant flow direction in the second refrigerant flow path (5), a wave bottom (41b) extending in the refrigerant flow direction in the second refrigerant flow path (5), and a wave The connecting portion (41c) connects the top portion (41a) and the wave bottom portion (41b). The connecting portion (41c) of the corrugated plate (41) has a plurality of louvers (42) extending from the wave crest (41a) to the wave bottom (41b) in the direction of refrigerant flow in the second refrigerant flow path (5). Are provided at intervals. The corrugated plate (41) may be brazed to the wave bottom (15b) of the fin (15).

  Other configurations are the same as those of the double-tube heat exchanger (1) of the first embodiment shown in FIGS.

  11 and 12 show a fifth embodiment of the double-pipe heat exchanger according to the present invention.

  In the double-pipe heat exchanger (50) shown in FIGS. 11 and 12, a contracted tube portion (14) is provided on the outer portion of the outer tube (2) in the longitudinal direction from both expanded portions (7) and (8). Are not formed, and an aluminum closing member (51) for closing both end openings of the first refrigerant flow path (4) is disposed at both ends of the outer pipe (2). The closing member (51) includes a large cylindrical portion (52) that is fitted from the outside to a portion near both ends of the outer tube (2) and brazed to the outer peripheral surface of the outer tube (23), and an inner tube (3). A small cylindrical part (53) fitted on the outer pipe (2) from the outside and brazed to the outer peripheral surface of the inner pipe (3), and the outer pipe (2) in the large cylindrical part (52) The end on the opposite side to the central portion in the length direction is connected to the end on the central portion in the length direction of the inner tube (3) in the small cylindrical portion (53), and the first coolant channel (4) is connected. It consists of a closing part (54) that closes the opening at both ends. 11 and 12, only the portion on the side of one expanded portion (7) where the refrigerant inlet (9) through which the high-pressure refrigerant inflow pipe (11) communicates is formed is shown. The same applies to the part (8) side.

  The closing member (51) is formed such that the inner peripheral surface of the large cylindrical portion (52) and the small cylindrical portion (53) is covered with the brazing material layer using an aluminum brazing sheet having a brazing material layer on at least one side. ing.

  The double pipe heat exchanger (50) includes an outer pipe (2), an inner pipe (3), a closing member (51), a pipe joint member (6), a high-pressure refrigerant inflow pipe (11), a high-pressure refrigerant outflow pipe ( 12), a pipe joint member (13), a fin (15), and a torsion plate (19) are combined and temporarily fixed, and are then brazed together in a furnace.

  Other configurations are the same as those of the double-tube heat exchanger (1) of the first embodiment shown in FIGS.

  FIG. 13 shows a sixth embodiment of the double-pipe heat exchanger according to the present invention.

  In the double-pipe heat exchanger (55) shown in FIG. 13, the expanded pipes (7) and (8) are not formed in the portions near both ends of the outer pipe (2), and both ends of the outer pipe (2) are formed. A refrigerant inlet (9) and a refrigerant outlet are formed in the portion closer to it. In addition, an aluminum closing member (56) that closes both end openings of the first refrigerant flow path (4) is disposed at both ends of the outer tube (2). The closing member (56) includes a large cylindrical portion (57) that is fitted from the outside to a portion near both ends of the outer tube (2) and brazed to the outer peripheral surface of the outer tube (3), and an inner tube (3). A small cylindrical part (58) fitted on the outer pipe (2) from the outside and brazed to the outer peripheral surface of the inner pipe (3), and the outer pipe (2) of the large cylindrical part (57) The end on the opposite side to the central portion in the length direction is connected to the end on the central portion in the length direction of the inner tube (3) in the small cylindrical portion (58), and the first coolant channel (4) is connected. It consists of a closing part (59) that closes the opening at both ends. In FIG. 13, only one portion where the refrigerant inlet (9) through which the high-pressure refrigerant inlet pipe (11) communicates is formed is shown, but the other side where the other refrigerant outlet is formed is also shown. It is the same.

  The closing member (56) is formed so that the inner peripheral surface of the large cylindrical portion (57) and the small cylindrical portion (58) is covered with the brazing material layer using an aluminum brazing sheet having a brazing material layer on at least one side. ing.

  The double pipe heat exchanger (55) includes an outer pipe (2), an inner pipe (3), a closing member (56), a pipe joint member (6), a high-pressure refrigerant inflow pipe (11), a high-pressure refrigerant outflow pipe ( 12), a pipe joint member (13), a fin (15), and a torsion plate (19) are combined and temporarily fixed, and are then brazed together in a furnace.

  Other configurations are the same as those of the double-tube heat exchanger (1) of the first embodiment shown in FIGS.

  In the double pipe heat exchangers (50) and (55) of the fifth and sixth embodiments described above, the protrusion (3a) on the outer peripheral surface of the inner pipe (3) is the outer pipe ( It is excised or crushed at the part protruding outward from 2).

  In the double pipe heat exchanger (35) (40) (50) (55) of the third to sixth embodiments described above, the double pipe heat exchanger (30) of the second embodiment is used. Similarly, a plurality of spirally recessed grooves (31) recessed outward are formed on the inner peripheral surface of the inner pipe (3) by deforming the peripheral wall of the inner pipe (3). Spiral ridges (32) may be formed on the outer peripheral surface of (3). In the double-tube heat exchanger (35) of the third embodiment, the twist direction of the spiral groove (31) is the twist direction of the spiral groove (37) of the cylindrical body (36). The reverse direction is preferred.

  When the spiral ridge (32) is formed in the double-tube heat exchanger (35) (40) of the third and fourth embodiments, the contracted tube portion (14) in the spiral ridge (32) is formed. And the corresponding portion are crushed when forming the contracted tube portion (14) in the expanded portion (7) (8) of the outer tube (2), and the inner peripheral surface of the contracted tube portion (14) and the inner tube (3 ) Between adjacent crushed spiral ridges (32) are filled with brazing material.

  When the spiral ridges (32) are formed in the double-tube heat exchangers (50) and (55) of the fifth and sixth embodiments, the spiral ridges (32) are formed on the inner pipe (3). Between the inner peripheral surface of the contraction pipe part (14) and the adjacent crushing spiral ridges (32) adjacent to each other in the inner pipe (3). The gap is filled with brazing material.

  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) (30) (35) (40) (50) (55): 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
(16): Louver
(17): Refrigerant passage hole
(18): Air gap
(19): Torsion plate (Diffusion member)
(31): Spiral groove
(36): Cylindrical body (Diffusion member)
(37): Spiral groove
(41): Corrugated plate (Drift member)
(41a): Wave peak
(41b): Wave bottom
(41c): Connection part
(51) (56): Closing member
(52) (57): Large cylindrical part
(53) (58): Small cylindrical part
(54) (59): Closure

Claims (12)

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 double-tube heat exchanger,
Along the inner peripheral surface of the inner tube, the wave crest portion, the wave bottom portion, and a connecting portion that connects the wave crest portion and the wave bottom portion are formed, and the wave crest portion and the wave bottom portion face the refrigerant flow direction in the second refrigerant flow path. A double-tube heat exchanger in which corrugated fins are arranged, the wave crests of the fins are joined to the inner peripheral surface of the inner tube, and a refrigerant passage hole is formed in the connecting portion of the fins. A plurality of louvers extending in the direction from the wave crest to the wave bottom are provided at intervals in the refrigerant flow direction in the second refrigerant flow path at the fin connection, and the louver is provided so that a refrigerant passage hole is formed in the connection. The double pipe heat exchanger according to claim 1, wherein: The double-tube heat exchanger according to claim 2, wherein all louvers provided in the connecting portion are inclined in the same direction with respect to the refrigerant flow direction in the second refrigerant flow path. A gap is formed in a radially inner portion of the inner pipe with respect to the fin in the inner pipe, and a drift member for drifting the refrigerant flowing in the gap to the fin side is disposed in the gap. A double tube heat exchanger according to any one of the above. The double-tube heat exchanger according to claim 4, wherein the drift member is a torsion plate. A plurality of spiral grooves recessed outward are formed on the inner peripheral surface of the inner tube by deforming the peripheral wall of the inner tube, and the twist direction of the torsion plate and the twist direction of the spiral groove are The double-pipe heat exchanger according to claim 5, which is in the reverse direction. The double-tube heat exchanger according to claim 4, wherein the drift member comprises a cylindrical body having a spiral groove formed on the outer peripheral surface. The double-pipe heat exchanger according to claim 7, wherein the columnar body is formed of a cylinder closed at both ends, and a spiral groove is formed by deforming a peripheral wall of the cylinder. A plurality of spiral grooves recessed outward are formed on the inner peripheral surface of the inner tube by deforming the peripheral wall of the inner tube, and the spiral grooves on the outer peripheral surface of the columnar body serving as the drift member The double-pipe heat exchanger according to claim 7 or 8, wherein the twist direction of the inner tube is opposite to the twist direction of the spiral groove on the inner peripheral surface of the inner tube. The drift member is made of a corrugated plate arranged so as to cross the gap in the cross section, and the corrugated plate is made of a wave crest portion, a wave bottom portion and a connecting portion connecting the wave crest portion and the wave bottom portion, and the wave crest portion and the wave bottom portion. The double-pipe heat exchanger according to claim 4, wherein is oriented in the refrigerant flow direction in the second refrigerant flow path. Closing members that close both end openings of the first refrigerant flow path are disposed at both ends of the outer tube, and the closing members are fitted from the outside to portions near both ends of the outer tube and brazed to the outer peripheral surface of the outer tube. A large cylindrical portion, a small cylindrical portion that is fitted from the outside to a portion of the inner tube near the both ends of the outer tube, and brazed to the outer peripheral surface of the inner tube, and a central portion in the lengthwise direction of the outer tube in the large cylindrical portion 11. A closed portion that connects an end opposite to the side and an end of the small cylindrical portion on the side of the central portion in the length direction of the inner tube and closes both ends of the first refrigerant flow path. A double tube heat exchanger according to any one of the above. 12. The double pipe according to claim 11, wherein the closing member is formed using a brazing sheet having a brazing material layer on at least one side so that the inner peripheral surfaces of the large cylindrical portion and the small cylindrical portion are covered with the brazing material layer. Type heat exchanger.

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