JP2003156294A - Duplex tube heat exchanger, its manufacturing method and secondary refrigerant type air conditioner using duplex tube heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve performance of a duplex tube heat exchanger. SOLUTION: A secondary refrigerant passage 4 in a clearance between positions of inner pipes 3A-3D and an outer pipe 1 is maintained constant by spacers 7 mounted with specified intervals by arranging a plurality of inner pipes 3A-3D twisted in a spiral shape respectively around an shaft center of the outer pipe 1 inside the outer pipe 1. A heat exchanging area is increased by making the inner pipes in a spiral shape of a plurality of numbers, and the heat transfer performance is increased by promoting turbulence of water flowing in the secondary refrigerant passage of the outer pipe and the inner pipes.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a double-tube heat exchanger for exchanging heat between a primary-side refrigerant and a secondary-side refrigerant, a method for producing the same, and a secondary tube heat-exchanged by the double-tube heat exchanger. The present invention relates to a secondary refrigerant type air conditioner that performs air conditioning using a side refrigerant.

[0002]

2. Description of the Related Art A conventional double tube heat exchanger has an inner tube loosely fitted in an outer tube, and a primary side refrigerant (or a secondary side refrigerant) is placed in a gap between the outer tube and the inner tube. In addition to flowing, the secondary side refrigerant (or primary side refrigerant) is caused to flow through the inner pipe for heat exchange. Since it has a simple structure and can be manufactured at low cost, for example, the intermediate heat of the secondary refrigerant type air conditioner. It is used as an exchange.

FIG. 5 shows a conventional example of a double-tube heat exchanger. A plurality of fins 102a for enhancing heat exchange performance are provided inside the outer tube 101 along the axial direction at regular intervals (angles) on the outer peripheral portion. The inner pipe 102 protruding from the inner pipe 102 is inserted into the gap 103 between the outer pipe 101 and the inner pipe 102, and CFC as the primary-side refrigerant is flowed in the gap 104 between the outer pipe 101 and the inner pipe 102. Are doing.

In FIG. 5, the fins 102 are provided for high performance.
Although the inner pipe 102 with a is used, there are various shapes of the inner pipe 102, and an inner pipe with a petal-shaped cross section or an inner pipe with a special fin that is twisted in a spiral shape is used. There are also examples of using it.

Further, normal pipes are used as the inner pipe and the outer pipe, and in the gap between the outer pipe and the inner pipe, the refrigerant flowing through the gap between the outer pipe and the inner pipe spirally flows around the inner pipe. There is also an example in which a thread or a plate-shaped member is inserted.

By the way, an intermediate heat exchanger adopting the double-tube heat exchanger performs heat exchange between the primary side refrigerant and the secondary side refrigerant, and uses the secondary side refrigerant for air conditioning. The sub-refrigerant air conditioner adopts the configuration shown in FIG. 6 in order to install the intermediate heat exchanger in the outdoor unit.

That is, the secondary refrigerant type air conditioner shown in FIG. 6 is an outdoor heat exchanger for exchanging heat with the outside air, a compressor,
At the upper part of the outdoor unit main body 110 that stores the related parts, a double-tube heat exchanger 120 that is an intermediate heat exchanger, a pump 125,
An intermediate heat exchange unit box 117, in which parts such as the water tank 126 are housed, is arranged.

The outdoor unit 110 and each component of the heat exchange unit box 117 are connected by connecting pipes 111 and 112 to circulate CFCs. Further, in the double tube heat exchanger 120, hot water is produced by exchanging heat between CFCs and water, and is sent to the indoor unit by the water connecting tube 115 to radiate heat indoors, and then the double tube through the water connecting tube 116. It is returned to the heat exchanger 120.

Refrigerant connecting tubes 113 and 114 are refrigerant circuits separately provided for supplying the primary refrigerant, and can be connected to other indoor units for heating or cooling.

[0010]

However, the above-mentioned conventional double-tube heat exchanger and the secondary refrigerant type air conditioner using the same have the following problems.

In the conventional double-tube heat exchanger, even if a finned tube or a tube having a flower pattern cross section is used for the inner tube 102, the performance is several tens of percent as compared with the case of using a normal bare tube. Only improvement. In addition, the cost of the inner tube with fins and the inner tube of the petal cross section is high, and the bending process is difficult, so the degree of freedom in the arrangement is low, and the manufacturing cost of the entire double-tube heat exchanger increases. there were.

Further, in the secondary refrigerant type air conditioner, the heat exchange unit box 117 is mounted on the same outdoor unit body 110 as the outdoor unit in which the double pipe heat exchanger 120 directly sends the primary refrigerant to the indoor unit. There is a problem that the outdoor unit body becomes large in size because it is installed.

The present invention solves the above problems, a high-performance double-tube heat exchanger and a method for manufacturing the same, and a secondary tube using the double-tube heat exchanger that can be efficiently housed to reduce the size of the outdoor unit. A refrigerant type air conditioner is provided.

[0014]

In order to achieve the above object, a double pipe heat exchanger according to a first aspect of the present invention is an outer pipe to which one of a primary side refrigerant and a secondary side refrigerant is sent, A plurality of inner pipes arranged in the outer pipe spirally twisted around the axis of the outer pipe to send the other refrigerant, and one refrigerant and the inner pipe sent to the outer pipe And is heat-exchanged with the other refrigerant.

According to the above structure, the heat exchange area is expanded by using the plurality of spirally twisted inner tubes, and the turbulent flow of one of the refrigerant flowing between the outer tube and the inner tube is promoted. Thus, the heat exchange performance of the double tube heat exchanger can be significantly improved.

According to a second aspect of the present invention, in the double-tube heat exchanger according to the first aspect, a positioning member for holding the position of each inner tube in the outer tube and turbulently flowing the other refrigerant is provided at predetermined intervals. It is arranged for each.

According to the above structure, the positioning means allows
By keeping the positional relationship of multiple spirally twisted inner tubes constant, it is possible to prevent the heat exchange area from decreasing due to the contact between inner tubes, and to eliminate the unevenness of the inner tubes in the outer tubes and perform heat exchange. It is possible to prevent the deterioration of the capacity, and to make the refrigerant flowing between the outer pipe and the inner pipe turbulent to assist the effective heat exchange. As a result, the heat exchange performance of the double-tube heat exchanger can be improved, and the heat exchange performance can be uniformly performed without variation depending on the parts.

According to a third aspect of the present invention, there is provided the double-tube heat exchanger according to the second aspect, wherein the positioning member is a linear member fitted around the inner tubes. According to the above configuration, the positioning member can be provided at low cost by shaping the linear member, which can contribute to the cost reduction of the double-pipe heat exchanger.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a double-tube heat exchanger, wherein a helical shape around an axis of the outer pipe is provided in an outer pipe to which one of the primary side refrigerant and the secondary side refrigerant is sent. When manufacturing a double-pipe heat exchanger in which a plurality of inner pipes in which the other refrigerant is twisted and sent to the other refrigerant are arranged, an inner pipe group in which a plurality of straight tubular inner pipes are bundled is inserted into the outer pipe. By twisting both ends of the inner tube group around the axis of the outer tube, the inner tubes are formed in a spiral shape.

According to the above structure, the outer tube is used as a guide.
Since it is possible to give a spiral shape to each of the inner tubes by collectively processing them into the inner tube group at one time, the inner tubes can be easily processed and the double tube heat exchanger can be supplied at a low cost.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a double-tube heat exchanger, wherein a helical shape around an axis of the outer pipe is provided in an outer pipe to which one of the primary side refrigerant and the secondary side refrigerant is sent. When manufacturing a double-tube heat exchanger in which a plurality of inner tubes in which the other refrigerant is twisted and sent to the other refrigerant is arranged, a plurality of straight tubular inner tubes are bundled to form an inner tube group, and the inner tube group is formed. While holding both ends of the inner tube group, the inner tube group is twisted around the axis to form each inner tube in a spiral shape to form a spiral inner tube group, and the inner tube group is inserted into the outer tube.

According to the above construction, since the inner tube group is twisted to give a spiral shape and then inserted into the outer tube, it becomes easy to manage the processing and the inner tube can be formed into a spiral shape with high accuracy.
The double tube heat exchanger can be manufactured with high accuracy.

A secondary refrigerant type air conditioner according to claim 6 is
An outdoor unit that cools or heats the primary side refrigerant using a refrigeration heat pump cycle, an intermediate heat exchanger that is provided in the outdoor unit and that performs heat exchange between the primary side refrigerant and the secondary side refrigerant, and the secondary unit. An indoor unit that performs air conditioning by cooling or heating with a side refrigerant, wherein the intermediate heat exchanger is configured by a double-tube heat exchanger and is arranged around the orifice portion of the blower fan of the outdoor unit. is there.

According to the above construction, the double-tube heat exchanger can be efficiently arranged in the empty space around the orifice portion of the outdoor unit blowing fan, and the secondary refrigerant type air conditioner can be miniaturized. be able to.

A secondary refrigerant type air conditioner according to claim 7 is
In the configuration according to claim 6, the intermediate heat exchanger is defined by claim 1.
It is configured by the double-tube heat exchanger according to any one of 1 to 3.

According to the above construction, by using the double-tube heat exchanger having a high heat exchange performance per unit, even if the space around the orifice portion is small, it can be sufficiently accommodated and the miniaturization is promoted. can do.

The secondary refrigerant type air conditioner according to claim 8 is
The structure according to claim 6 or 7, wherein at least the refrigerant inlet of the refrigerant inlet and the refrigerant outlet of the double-pipe heat exchanger that branches or joins the refrigerant between the single pipe and the plurality of inner pipes is It is arranged so that the flow at the branch portion is in the vertical direction.

According to the above construction, by arranging the branch portion of the refrigerant inlet for dividing the single pipe into a plurality of inner pipes to supply the refrigerant in the vertical direction, the refrigerant is evenly distributed to each inner pipe. It can be distributed and supplied well. Thereby, the performance of the double-tube heat exchanger can be sufficiently brought out, and the performance of the secondary refrigerant type air conditioner can be improved.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a double-tube heat exchanger according to the present invention will be described below with reference to FIGS. 1 and 2.

As shown in FIG. 1, the outer pipe 1 having a circular cross section is provided with connection joints 2A and 2B on both sides, and the axial center of the outer pipe 1 is placed in the outer pipe 1 between these connection joints 2A and 2B. Freon F, which is the primary side refrigerant, twisted around each other in a spiral shape
A plurality of (4 in the figure) inner pipes 3A to 3D for delivering the are arranged. And, in the outer pipe 1, the outer pipe 1 and the inner pipe 3A
3D to 3D and gaps between the inner pipes 3A to 3D, secondary side refrigerant passages 4 for sending water W as the secondary side refrigerant are formed.

At both ends of the outer pipe 1, there are provided an inlet branch joint 5 and an outlet branch joint 6 in which the inner pipes 3A to 3D are straightly taken out from the connection joints 2A and 2B, respectively, and the takeout ports are integrated. The inlet branch joint 5
A refrigerant inlet 3a is formed in the outlet branch joint 6 and a refrigerant outlet 3b is formed in the outlet branch joint 6. Further, a water outlet 4b for discharging the water W from the secondary side refrigerant passage 4 is formed in the connection joint 2A on the refrigerant inlet 5a side, and the connection joint 2 on the refrigerant outlet 3b side is formed.
A water inlet 4a for supplying water W to the secondary side refrigerant passage 4 is formed in B.

Further, in the outer pipe 1, spacers 7 which are positioning members attached to the inner pipes 3A to 3D at predetermined intervals in the length direction are arranged.
Is formed in a star shape when viewed from the front, and the inner tube 3A is formed in each recess.
To 3D are retained, whereby the gap between the inner pipes 3A to 3D and the gap between the inner pipes 3A to 3D and the inner surface of the outer pipe 1 are kept constant over the entire length, and the secondary side refrigerant passage 4 is retained.
It is configured to form a turbulent flow in the water W sent to the. Therefore, the inner pipes 3A to 3D are formed by the spacer 7.
It is possible to prevent a decrease in the heat exchange area due to the mutual contact, and a decrease in the heat exchange capacity due to the deviation of the inner tubes 3A to 3D in the outer tube 1.

The spacers 7 are formed by bending one thin plate 7a made of metal, resin, or the like into a recess for holding the inner tubes 3A to 3D, for example, by bending it into a star shape. 7b is provided. A thin plate does not necessarily have to be used to form the spacer 7, but a thin plate can be formed by a simple bending process.

As shown in FIG. 4, the positioning member is wound around the inner pipes 3A to 3D in the directions shown by the arrows a to g using the wire 8a, and the spacer 8 which is processed by pulling out the end in the direction h is used. The wire 8a may be used for the inner pipe 3
A to 3D are held at predetermined positions on the outer tube 1. With this spacer 8, without using a mold for processing,
The predetermined purpose can be more easily achieved, the manufacturing cost can be reduced, and the double-pipe heat exchanger can be supplied at low cost.

When the double-tube heat exchanger 10 is used in a secondary refrigerant type air conditioner, which will be described later, the double-tube heat exchanger 10 is spirally wound into a predetermined size and used. In the above configuration, the Freon F, which is the primary side refrigerant, is supplied from the refrigerant inlet 3a to the inner pipes 3A to 3D via the inlet branch joint 5.
The refrigerant is discharged from the refrigerant outlet 3b of the outlet branch joint 6. Also,
The water W as the secondary side refrigerant is supplied to the secondary refrigerant passage 4 from the water inlet 4a of the connection joint 2B, and the water outlet 4 of the connection joint 2A.
Fluorine F and water W are discharged from b and exchange heat with each other via the tube walls of the inner tubes 3A to 3D.

According to the above embodiment, since the four inner tubes 3A to 3D are inserted in the outer tube 1, the inner tubes 3A to 3D are inserted.
Compared to disposing one inner tube having the same cross-sectional area as the total cross-sectional area of D, the surface area per cross-sectional area is doubled and the heat exchange performance is also doubled.

Further, since the inner pipes 3A to 3D each have a spiral shape, the lengths of the inner pipes 3A to 3D inserted into the outer pipe 1 having the same length are different from those when the straight pipe is inserted. And the heat exchange area is further increased.

Further, the spiral shape of the inner pipes 3A to 3D means that the water W flowing in the secondary side refrigerant passage 4 between the outer pipe 1 and the inner pipes 3A to 3D is in contact with the wall of the inner pipes 3A to 3D. To a greater degree,
Heat transfer is promoted at the interface between the tube wall and the water W.

Furthermore, the inner pipes 3A ...
Since the gaps between the 3Ds and the gaps between the inner pipes 3A to 3D and the inner surface of the outer pipe 1 are kept constant over the entire length, and a turbulent flow is formed in the water W sent to the secondary side refrigerant passage 4, The heat exchange area does not decrease due to the contact between the tubes 3A to 3D, and the heat exchange capacity does not decrease due to the deviation of the inner tubes 3A to 3D in the outer tube 1. In addition, the turbulent flow formed in the water W mixes the water W, thereby improving the heat transfer efficiency. Therefore, the heat exchange performance of the double tube heat exchanger 10 can be significantly improved.

Next, a method for manufacturing the double tube heat exchanger 120 will be described. As a method of manufacturing the double-tube heat exchanger 10, it is effective to bundle the straight tubular inner tubes and then collectively give the spiral shape instead of assembling the inner tubes each formed into a spiral shape.

That is, as a first manufacturing method, first, an inner tube group in which a predetermined number (four in the figure) of straight tubular inner tubes 3A to 3D are bundled is inserted into the outer tube 1, and then both end portions of the inner tube group are inserted. Is fixed in a predetermined arrangement using a jig or the like, and then twisted to the inner tube group around the axis of the outer tube 1 via the jig.

According to the above method, the outer pipe 1 is replaced by the inner pipes 3A to 3A.
Since it plays a role of a guide pipe that regulates the movable range of D, each inner pipe of the inner pipe group 3 can be formed by using a simple jig.
A spiral shape can be given to A to 3D. Therefore,
The double tube heat exchanger can be supplied at low cost.

As a second manufacturing method, an inner tube group in which a predetermined number (four in the figure) of straight tubular inner tubes 3A to 3D are bundled,
This is a method in which the inner tube group is fixed in a predetermined arrangement, twisted about the axis of the inner tube group to form a spiral shape, and then inserted into the outer tube 1.

According to the above method, since the spiral shape is formed before inserting the inner pipes 3A to 3D into the outer pipe 1, it becomes easy to manage the working process. Further, after the spacer 7 (8) which is a positioning means for the inner pipes 3A to 3D is attached, the inner pipe group is formed in a spiral shape so that the spacer 7 (8) can move the movable range of the inner pipes 3A to 3D. Since it is regulated, the spiral shape can be formed only by using a simple jig. Furthermore, since the spiral shape is imparted in a state where the inner pipes 3A to 3D can be directly operated, it is possible to easily manage the processing and improve the manufacturing accuracy.

As the material of the outer tube 1 and the inner tubes 3A to 3D of the double tube heat exchanger 10, a copper material having excellent thermal conductivity and workability is suitable, but a stainless material having excellent corrosion resistance. Needless to say, the same effect can be obtained by using a titanium material. Further, a resin material can be used for the outer tube 1 to which a high pressure is not applied, and since the outer tube 1 made of the resin material has a heat insulating effect of suppressing heat loss due to heat radiation, the heat insulating member covering the outer tube 1 can be removed or reduced. it can.

In the above embodiment, the bare pipe 3 is used as the inner pipe.
Although A to 3D were used, the heat exchange performance can be further improved by using a grooved tube that is often used in the air heat exchanger of the air conditioner.

Further, although the flows of the freon F and the water W in the double-tube heat exchanger 10 are opposite flows which face each other, the same effect can be obtained by using parallel flows in the same direction depending on the purpose. Further, instead of the Freon F and the water W, the same effect can be obtained by using another refrigerant.

Next, an embodiment of a secondary refrigerant type heat exchanger using the double tube heat exchanger will be described with reference to FIG.
In the outdoor unit 21 of the air conditioner using the double tube heat exchanger,
Comprised of a compressor 22, an outdoor heat exchanger 23, an outdoor fan 24, an air guider 26 having an orifice portion 25, an electrical equipment portion 27, a four-way valve 28, a double pipe heat exchanger 10, a water tank 31, a water pump 32, etc. There is. Note that in FIG. 3, the expansion valve and a part of the housing are omitted for the sake of explanation.

In the outdoor unit 21, the primary side refrigerant, Freon F, is compressed by the compressor 22, then passes through the four-way valve 28, the refrigerant outlet port 41, and the refrigerant inlet 3a to the double pipe heat exchanger 10. enter. Then, after heat-dissipating and condensing while reaching the refrigerant outlet 3b, an expansion valve (not shown) is introduced from the refrigerant return port 42.
Through the four-way valve 28 to return to the compressor 22.

The water W as the secondary side refrigerant is circulated by the water pump 32, and the water W recovered through the return port 33 from the room enters the water inlet 4a of the double tube heat exchanger 220. , Heated to reach the water outlet 4b and becomes hot water, which enters the water tank 31. The warm water W is supplied from the water tank 31 to the water pump 32.
Is sent out to the indoor unit through the entrance 34 to the room, radiates heat and returns to the return port 33.

The above is the case where hot water is produced for heating. The flow is changed by the four-way valve 28 so that the outdoor heat exchanger 23 radiates and condenses the Freon F and the double-tube heat exchanger 10 absorbs heat and evaporates it. It is also possible to make cold water.

The present invention focuses on the fact that the double-tube heat exchanger 10 requires a large space for storage by being wound in a spiral shape, but has a hollow portion in the central portion. On the other hand, the outdoor unit 21 needs an orifice on the lee side of the outdoor fan 24,
In the outer peripheral portion of the orifice portion 25 of the air guider 26,
Attention was paid to the fact that a large cylindrical space was created in which the double-tube heat exchanger 10 wound in a spiral shape could be accommodated.

That is, in this embodiment, the double pipe heat exchanger 10 is arranged and housed in the space formed on the outer peripheral portion of the orifice portion 25. Here, although the same arrangement is possible using the conventional double-tube heat exchanger, if the double-tube heat exchanger 10 described in the above embodiment is used, the unit length per unit length can be increased. Since the heat exchange performance is high, the length can be shortened, and the double-tube heat exchanger 10 can be sufficiently accommodated even in a small space on the outer peripheral portion of the orifice portion 25. Thereby, the outdoor unit 2 of the secondary refrigerant type air conditioner using the double-tube heat exchanger 10
1 can be miniaturized. The water pump 32 and the water tank 31 are arranged between the air guider 26 and the housing (case) of the outdoor unit 21.

Further, in the double-pipe heat exchanger 10 spirally wound in this way, from the refrigerant inlet 3a which is a single pass (single pipe) of the refrigerant inlet 3a to the inner pipes 3A to 3D which are a plurality of passes. If uniform distribution and merging are not performed in the flow dividing part and the merging part from the inner pipes 3A to 3D having a plurality of passes to the refrigerant outlet 3b having a single pass, it causes a decrease in heat exchange performance. For this reason, in this embodiment, by arranging the connection joints 2A and 2B for sending or taking out the refrigerant so as to be vertically below the inner pipes 3a to 3d, the shunting of the Freon F is kept uniform. Is configured. As a result, the heat exchange performance can be sufficiently brought out, and the performance of the secondary refrigerant type air conditioner using the double pipe heat exchanger 10 can be further improved.

[0055]

As described above, according to the double-tube heat exchanger of claim 1, the heat exchange area is expanded and the outer tube is expanded by using a plurality of inner tubes twisted in a spiral shape. The turbulent flow of one of the refrigerants flowing between the inner pipe and the inner pipe can be promoted, and the heat exchange performance of the double-pipe heat exchanger can be significantly improved.

According to the double tube heat exchanger of claim 2,
By maintaining the positional relationship of the plurality of spirally twisted inner tubes constant by the positioning means, it is possible to prevent the heat exchange area from decreasing due to the contact between the inner tubes and to prevent the inner tubes from being biased in the outer tube. Without this, it is possible to prevent the heat exchange capacity from deteriorating, and to make the refrigerant flowing between the outer pipe and the inner pipe turbulent to assist the effective heat exchange. As a result, the heat exchange performance of the double-tube heat exchanger can be improved, and the heat exchange performance can be uniformly performed without variation depending on the parts.

According to the double-tube heat exchanger of claim 3,
By shaping the linear member, the positioning member can be provided at a low cost, which can contribute to the cost reduction of the double-tube heat exchanger.

According to the method for manufacturing a double-tube heat exchanger of claim 4, since the outer tube can be used as a guide, the inner tube group can be collectively processed into a spiral shape by a single process.
The inner pipe can be easily processed, and the double pipe heat exchanger can be supplied at a low cost.

According to the method of manufacturing a double-tube heat exchanger of claim 5, the inner tube group is twisted to give a spiral shape and then inserted into the outer tube, so that the inner tube is formed into a spiral shape with high accuracy. Therefore, the double tube heat exchanger can be manufactured with high accuracy because the processing can be controlled easily.

According to the secondary refrigerant type air conditioner of the sixth aspect, the double tube heat exchanger can be efficiently arranged in the empty space around the orifice portion of the outdoor unit blowing fan,
The secondary refrigerant type air conditioner can be downsized.

According to the secondary refrigerant type air conditioner of the seventh aspect, by using the double tube heat exchanger having a high heat exchange performance per unit, even if the space around the orifice portion is narrow, it is sufficiently possible. It can be stored, and miniaturization can be promoted.

According to the secondary refrigerant type air conditioner of claim 8, the branch portion of the refrigerant inlet for diverting the single pipe into the plurality of inner pipes to supply the refrigerant is arranged in the vertical direction. The refrigerant can be evenly distributed to each of the inner tubes to be satisfactorily supplied. Thereby, the performance of the double-tube heat exchanger can be sufficiently brought out, and the performance of the secondary refrigerant type air conditioner can be improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a double pipe heat exchanger according to the present invention.

FIG. 2 is a cross-sectional view taken along the line A-A ′ shown in FIG.

FIG. 3 is a partially exploded perspective view of an outdoor unit showing an embodiment of a secondary refrigerant type air conditioner using a double tube heat exchanger according to the present invention.

FIG. 4 shows a modified example of the spacer of the double-tube heat exchanger,
(A) is a front view of a spacer, (b) is explanatory drawing explaining the formation procedure of a spacer.

FIG. 5 is a cutaway perspective view showing a conventional double-tube heat exchanger.

FIG. 6 is a partially cutaway perspective view of an outdoor unit showing a conventional secondary refrigerant type air conditioner.

[Explanation of symbols]

W water F CFC 1 outer tube 2A, 2B connection joint 3A-3D inner tube 3a Refrigerant inlet 3b Refrigerant outlet 4 Refrigerant passage 4a water inlet 4b water outlet 5 inlet branch fittings 6 outlet connection fittings 7 Spacer 7a thin plate 7b mating part 8 spacers 8a wire 10 heat exchanger 21 outdoor unit 22 compressor 23 Outdoor heat exchanger 24 outdoor fan 25 Orifice part 26 Air Guider 31 water tank 32 water pump 33 Water return port 34 Water outlet

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yamaguchi Adult             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yukio Watanabe             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 3L054 BC01                 3L103 AA35 BB38 CC02 CC12 DD05                       DD38

Claims (8)

[Claims] 1. An outer pipe to which one of a primary-side refrigerant and a secondary-side refrigerant is sent, and an outer pipe in which the other refrigerant is arranged so as to be spirally twisted around the axis of the outer pipe. A plurality of inner pipes to be sent, wherein one of the refrigerants sent to the outer pipe and the other refrigerant sent to the inner pipe are configured to exchange heat with each other. Heavy pipe heat exchanger. 2. The double-tube heat exchange according to claim 1, wherein positioning members for holding the positions of the respective inner tubes in the outer tube and turbulently flowing the other refrigerant are arranged at predetermined intervals. vessel. 3. The positioning member is constituted by a linear member fitted around the inner pipe.
The described double-tube heat exchanger. 4. A plurality of refrigerants, which are spirally twisted around the axis of the outer tube and are sent to the other refrigerant, inside an outer tube to which one of the primary side refrigerant and the secondary side refrigerant is sent. When manufacturing a double-tube heat exchanger in which an inner tube is arranged, in the outer tube, an inner tube group in which a plurality of straight tubular inner tubes are bundled is inserted, and both ends of the inner tube group are arranged at the axial center of the outer tube. A method of manufacturing a double-tube heat exchanger, characterized by twisting around to form each of the inner tubes in a spiral shape. 5. A plurality of refrigerants, which are spirally twisted around the axis of the outer tube and are sent to the other refrigerant, in an outer tube to which one of the primary side refrigerant and the secondary side refrigerant is sent. When manufacturing a double-tube heat exchanger in which the inner tubes are arranged, a plurality of straight tubular inner tubes are bundled to form an inner tube group, and both ends of the inner tube group are held to keep the inner tube group around the axial center. A method for manufacturing a double-tube heat exchanger, characterized in that each inner tube is twisted to form a spiral shape to form a spiral inner tube group, and the inner tube group is inserted into the outer tube. 6. An outdoor unit for cooling or heating a primary side refrigerant using a refrigeration heat pump cycle, and an intermediate heat exchanger provided in the outdoor unit for exchanging heat between the primary side refrigerant and the secondary side refrigerant. And an indoor unit that cools or heats the secondary side refrigerant to perform air conditioning, and the intermediate heat exchanger is configured by a double-tube heat exchanger to surround the orifice portion of the blower fan of the outdoor unit. A secondary refrigerant type air conditioner, which is characterized in that 7. The secondary refrigerant air conditioner according to claim 6, wherein the intermediate heat exchanger is constituted by the double-tube heat exchanger according to any one of claims 1 to 3. 8. A refrigerant inlet and a refrigerant outlet of a double pipe heat exchanger for branching or joining the refrigerant between a single pipe and a plurality of inner pipes, wherein at least the refrigerant inlet has a flow at a branched portion of the refrigerant. The secondary refrigerant type air conditioner according to claim 6 or 7, wherein the secondary refrigerant type air conditioner is arranged in a vertical direction.