JP2003021475A - Heat exchanger and heat pump type water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger with satisfactory heat exchange efficiency while preventing corrosion due to electrolytic corrosion, and also to provide a heat pump type water heater capable of performing efficient heat pump operation. SOLUTION: The first heat exchange pipe 12A and the second heat exchange pipe 12B comprise metallic materials of the same quality. The cross-sectional shape of the second heat exchange pipe 12B inside which a heating medium flows is made circular or elliptic, while the cross-sectional shape of the first heat exchange pipe 12A inside which the liquid to be heat-exchanged flows is made non-circular in such a manner that the two opposed faces are recessed faces. At least a part of the second heat exchange pipe 12B is interposed in the recessed face parts 22A and 22B of the first heat exchange pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger and a heat pump type water heater.

[0002]

2. Description of the Related Art Generally, in a heat pump type hot water supply apparatus of this type, as described in Japanese Patent Laid-Open No. 2001-116357, a heat exchanger for refrigerant and water is used to generate heat and water of the refrigerant. By exchanging heat, the water can be heated and stored in a hot water supply tank or the like.

By the way, the conventional heat exchanger 1 for refrigerant and water is used.
As shown in FIG. 5, the first heat exchange pipe 2 through which the water in the hot water supply circuit flows and the second heat exchange pipe 3 in the refrigerant circulation circuit through which the high-temperature, high-pressure gas refrigerant compressed by the compressor flows are in contact with each other. In order to exchange heat with each other, the layers are alternately stacked and wound in a spiral shape, and are configured so that the entire shape is substantially cylindrical.

The lower end side of the heat exchanger 1 is placed on, for example, the bottom plate 4 of the outer case of the heat pump type water heater, and the fixing cover plate 5 and the bottom plate 4 of the outer case are covered on the upper end side. Is fixed in the outer case by using a fixture 6 such as a bolt and a nut.

By the way, in the above-mentioned conventional heat exchanger 1 for refrigerant-to-water, the first heat exchange pipe 2 through which water flows is often the case that the flowing water is drunk.
The second heat exchange pipe 3 through which the refrigerant flows is generally made of aluminum or an aluminum alloy, while it is made of copper or a copper alloy having a sterilizing action. As described above, when the first heat exchange pipe 2 and the second heat exchange pipe 3 which are in contact with each other are made of different metals, electrolytic corrosion is caused due to that,
The heat exchange pipe made of aluminum or aluminum alloy had to be subjected to surface treatment such as painting or alumite treatment to prevent electrolytic corrosion.

Further, although the cross-sectional shape of the first and second heat exchange pipes 2 and 3 is formed into a flat elliptical shape to increase the contact area as compared with a true circle, in order to secure a large contact area. It was just a step away.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to provide a heat exchanger having good heat exchange efficiency while preventing corrosion due to electrolytic corrosion. And to provide a heat pump type hot water heater capable of efficient heat pump operation.

[0008]

According to a first aspect of the present invention, there is provided a first heat exchange pipe in which a liquid to be heat exchanged flows, and a second heat exchange pipe in which a heat medium flows. A first heat exchange pipe and a second heat exchange pipe, wherein the first heat exchange pipe and the second heat exchange pipe are alternately superposed on each other and spirally wound. Are made of the same metal material as each other, and the cross-sectional shape of the second heat exchange pipe through which the heat medium flows is circular or elliptical, while the inside of the first heat exchange pipe through which the liquid to be heat-exchanged flows inside. The cross-sectional shape is a non-circular shape so that the two opposing surfaces are concave surfaces, and at least a part of the second heat exchange pipe is inserted in the concave surface portion of the first heat exchange pipe. Is characterized by.

The invention relating to the heat exchanger according to claim 2 is
The heat exchanger according to claim 1, wherein the first heat exchange pipe and the second heat exchange pipe are made of copper or a copper alloy.

The invention relating to the heat pump type hot water supply apparatus according to claim 3 includes a first heat exchange pipe through which hot and cold water flows,
A second heat exchange pipe in which a refrigerant flows, and the first heat exchange pipe and the second heat exchange pipe are alternately superposed on each other and spirally wound and heat for refrigerant water In a heat pump water heater having an exchanger, the first heat exchange pipe and the second heat exchange pipe are made of the same metal material, and the cross-sectional shape of the second heat exchange pipe in which the heat medium flows is circular. Shape or elliptical shape, while the first heat exchange pipe in which the liquid to be heat-exchanged flows has a non-circular cross-sectional shape such that the two facing surfaces are concave surfaces, and the first heat exchange At least a part of the second heat exchange pipe is interposed in the concave surface portion of the pipe.

The invention relating to the heat pump water heater according to claim 4 is the heat pump water heater according to claim 3, in which copper or copper alloy is used for the first heat exchange pipe and the second heat exchange pipe. It is characterized by

[0012]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. First, FIG. 1 is an overall schematic configuration diagram of a heat pump type hot water supply apparatus including an embodiment of a heat exchanger according to the present invention, and FIG. 2 is a schematic diagram showing a refrigerant circulation circuit and a hot water supply circuit.

In FIG. 1 and FIG. 2, a heat pump type water heater 10 comprises a refrigerant circulation circuit A comprising a compressor 11, a refrigerant heat exchanger 12 for water, a pressure reducing device 13 and an evaporator 14, a hot water storage tank 15 and a circulation circuit. The compressor 16 comprises a pump 16 and a hot water supply circuit B to which the refrigerant-to-water heat exchanger 12 is connected.
1, heat exchanger 12 for refrigerant to water, pressure reducing device 13, evaporator 1
4, the hot water storage tank 15, the circulation pump 16 and the like are housed in the outer case 17.

The outer case 17 is divided into an upper chamber 17A and a lower chamber 17B by a partition wall 18, and a compressor 11, an evaporator 14 and a blower for the evaporator 14 are provided in the upper chamber 17A. A blower 19 and the like are arranged, while the lower chamber 17B has a refrigerant-to-water heat exchanger 12 and a hot water storage tank 1 therein.
5, a circulation pump 16 and the like are arranged.

Reference numeral 20 denotes a frame serving as a bottom plate of the outer case 17, on which the heat exchanger 12 for refrigerant and water and the circulation pump 16 are mounted and fixed, and the hot water storage tank 15 is mounted via the supporting legs 15A. It is fixed.

In the heat pump type water heater 10 described above,
The superheated gas refrigerant such as high-temperature and high-pressure CO2 refrigerant discharged from the compressor 11 flows into the refrigerant-to-water heat exchanger 12 and heats the water sent from the circulation pump 16. Then, the condensed and liquefied refrigerant is decompressed by the decompression device 13 and flows into the evaporator 14, where it absorbs atmospheric heat to be evaporated and gasified, and then returns to the compressor 11. On the other hand, the hot water heated in the refrigerant-to-water heat exchanger 12 flows into the upper part of the hot water storage tank 15, and the hot water storage tank 15
The hot water stored in the hot water storage tank 15 is supplied to the utilization unit as needed.

Next, the refrigerant-to-water heat exchanger (heat exchanger) 12 will be described in detail with reference to FIGS. Figure 3
FIG. 4 is a vertical cross-sectional configuration diagram of a heat exchanger for refrigerant-to-water, and FIG. 4 is an enlarged view of a main part of FIG.

In FIG. 3, the refrigerant-to-water heat exchanger 1 is shown.
2 is configured to include a first heat exchange pipe 12A inside which water (liquid to be exchanged) sent from the circulation pump 16 flows, and a superheated gas refrigerant (heat medium) inside.
The heat exchange pipes 12A and the second heat exchange pipes 12B are alternately superposed on each other and spirally wound, and are formed in a generally cylindrical shape as a whole.

Here, the first heat exchange pipe 12A is
For example, the second heat exchange pipe 12B is made of a copper pipe having a thickness of about 1 mm and an outer diameter of about 20 mm.
Is made of the same metal material as the first heat exchange pipe 12A, for example, a copper pipe having a thickness of about 1 mm and an outer diameter of about 10 mm.

In the first heat exchange pipe 12A, the upper and lower two surfaces facing each other are inwardly arcuate concave surfaces.
By drawing a copper pipe using a drawing machine, the radial cross-sectional shape of the copper pipe is made non-circular as shown in FIG. 22A and 22B are the concave surface portions.

On the other hand, the second heat exchange pipe 12B has an elliptical cross section as shown in FIG. 4, by drawing a copper pipe by using a drawing machine.

The refrigerant-to-water heat exchanger 12 is
As shown in FIG. 4, at least a part of the second heat exchange pipe 12B is interposed between the concave surface portions 22A and 22B of the first heat exchange pipe 12A, which face each other.
The heat exchange pipe 12B is wrapped in the upper and lower first heat exchange pipes 12A.

As shown in FIG. 3, the refrigerant-to-water heat exchanger 12 is mounted on the frame 20 of the outer case 17 and is covered with a fixing cover plate 23 at the upper end thereof to fix the same. The cover plate 23 and the pedestal 20 are fastened and fixed on the pedestal 20 by being fastened by fastening tools 24 such as bolts and nuts. Reference numeral 25 is a heat insulating material that covers the outer periphery of the refrigerant-to-water heat exchanger 12.

The refrigerant-to-water heat exchanger 12 configured as described above has inward arcuate concave surface portions 2 on the two upper and lower surfaces of the first heat exchange pipe 12A where the water (liquid to be exchanged) flows.
2A and 22B are formed, and these concave surface portions 22A and 22B are formed.
Both heat exchange pipes 12A and 12B are spirally wound with a part of the second heat exchange pipe 12B in which a superheated gas refrigerant (heat medium) having an elliptical cross section in the radial direction flows therein. By turning, the shape of the heat exchange pipes 12A, 1A is substantially cylindrical.
2B is processed by using a copper pipe as the metal of the same material.

Therefore, there is no concern that galvanic corrosion will occur between the first heat exchange pipe 12A and the second heat exchange pipe 12B which are in contact with each other, and it is possible to prevent corrosion and perforation due to galvanic corrosion. Of course, since the second heat exchange pipe 12B through which the superheated gas refrigerant (heat medium) on the high temperature side flows is wrapped by the first heat exchange pipe 12A through which water (the liquid to be exchanged) on the low temperature side flows, the superheated gas refrigerant ( The exposed area of the second heat exchange pipe 12B through which the heat medium) flows can be reduced, and the contact area between the two heat exchange pipes 12A and 12B can be increased, while wasteful heat dissipation from the second heat exchange pipe 12B can be suppressed. It has become possible to dramatically improve the exchange efficiency.

Further, in the heat exchanger 12 for refrigerant and water configured as described above, the cross-sectional shape of the first heat exchange pipe 12A is a non-circular shape having the concave and convex surface portions 22A and 22B on the two upper and lower surfaces. Both heat exchange pipes 1 compared to conventional components
When 2A and 12B are alternately overlapped with each other and spirally wound, the workability is good, the height dimension can be shortened, and the size can be reduced.

Also, the refrigerant-to-water heat exchanger 12 having the above structure.
In the heat pump water heater 10 including the heat exchanger 12 for cooling water, the heat exchanger 12 for refrigerant can be made compact, so that the inside of the outer case 17 can be efficiently used, and the heat exchange efficiency between water and the refrigerant can be improved. Good heat pump operation.

In this embodiment, the first heat exchange pipe 1
Although the copper pipes are used for the 2A and the second heat exchange pipes 12B, both the heat exchange pipes 12A and 12B may be copper alloy pipes or stainless pipes. Furthermore, although the second heat exchange pipe 12B has an elliptical cross section, it may have a perfect circular shape.

Further, although the embodiment of the present invention has been described above, various alternatives, modifications or variations can be made by those skilled in the art based on the above description, and various alternatives are possible without departing from the gist of the present invention. It is intended to include examples, modifications or variations.

[0030]

As described above, according to the first aspect of the present invention.
The heat exchanger according to the first aspect includes a first heat exchange pipe in which a liquid to be heat exchanged flows, and a second heat exchange pipe in which a heat medium flows, and the first heat exchange pipe and the second heat exchange pipe. In a heat exchanger in which the first heat exchange pipe and the second heat exchange pipe are made of the same metal material and have a heat medium inside, The cross-sectional shape of the flowing second heat exchange pipe is circular or elliptical, while the cross-sectional shape of the first heat exchange pipe in which the liquid to be heat-exchanged flows is non-convex so that the two opposing surfaces are concave surfaces. Since it is circular and at least a part of the first heat exchange pipe is interposed in the concave surface portion of the first heat exchange pipe, corrosion caused by electrolytic corrosion is caused. Second heat exchange as well as preventing holes and perforations Since the ip is wrapped by the first heat exchange pipe on the low temperature side, the exposed area of the second heat exchange pipe on the high temperature side can be reduced, and the wasteful heat dissipation can be suppressed while increasing the contact area of both heat exchange pipes. The heat exchange efficiency is further improved.

A heat pump type hot water supply apparatus according to a third aspect of the present invention is provided with a first heat exchange pipe through which hot water flows and a second heat exchange pipe through which a refrigerant flows, and these first heat exchange pipes are provided. A heat pump type water heater including a refrigerant-to-water heat exchanger in which a pipe and a second heat exchange pipe are alternately stacked and spirally wound.
The first heat exchange pipe and the second heat exchange pipe are made of the same metal material as each other, and the heat medium flows inside.
The cross-sectional shape of the heat exchange pipe is circular or elliptical, while the cross-sectional shape of the first heat exchange pipe through which the liquid to be heat-exchanged flows is non-circular so that the two opposing surfaces are concave surfaces. Further, since at least a part of the first heat exchange pipe is interposed in the concave surface portion of the first heat exchange pipe, the compact heat exchanger 12 for refrigerant to water is compact. The efficiency of heat exchange between water and refrigerant can be improved, and efficient heat pump operation can be performed.

[Brief description of drawings]

FIG. 1 is an overall schematic configuration diagram of a heat pump water heater including an embodiment of a heat exchanger according to the present invention.

FIG. 2 is a schematic diagram showing a refrigerant circulation circuit and a hot water supply circuit of the heat pump type hot water supply device according to the present invention.

FIG. 3 is a vertical cross-sectional view of a heat exchanger for refrigerant and water showing an embodiment of a heat exchanger according to the present invention.

FIG. 4 is an enlarged view of a main part of FIG.

FIG. 5 is a vertical cross-sectional view of a refrigerant-to-water heat exchanger showing a conventional example.

[Explanation of symbols]

10 Heat pump water heater 11 compressor 12 Refrigerant-to-water heat exchanger (heat exchanger) 12A First heat exchange pipe 12B Second heat exchange pipe 13 Pressure reducing device 14 Evaporator 15 Hot water storage tank 16 Circulation pump 17 exterior case 22A Concave surface portion of the first heat exchange pipe (upper side) 22B Concave surface portion of the first heat exchange pipe (lower side)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F28F 19/00 511 F28F 19/00 511C (72) Inventor Kazuhiko Harima 1 Otsukimachi, Ashikaga-shi, Tochigi Sanyo Denki Air Conditioning Co., Ltd. F term (reference) 3L036 AA04 AA05 AA41 AA42 3L103 AA12 AA36 BB43 CC02 CC30 DD05 DD09 DD36 DD82

Claims (4)

[Claims] 1. A first heat exchange pipe in which a liquid to be heat exchanged flows, and a second heat exchange pipe in which a heat medium flows, wherein the first heat exchange pipe and the second heat exchange pipe are alternately arranged. In the heat exchanger spirally wound so as to be overlapped with each other, the first heat exchange pipe and the second heat exchange pipe are made of the same metal material, and the heat medium flows inside. Two
The cross-sectional shape of the heat exchange pipe is circular or elliptical, while the cross-sectional shape of the first heat exchange pipe in which the liquid to be heat-exchanged flows is non-circular so that the two opposing surfaces are concave. A heat exchanger characterized in that at least a part of the second heat exchange pipe is interposed in the concave surface portion of the first heat exchange pipe. 2. The heat exchanger according to claim 1, wherein the first heat exchange pipe and the second heat exchange pipe are made of copper or a copper alloy. 3. A first heat exchange pipe through which hot and cold water flows, and a second heat exchange pipe through which a refrigerant flows inside, wherein the first heat exchange pipe and the second heat exchange pipe are alternately arranged. In a heat pump type hot water supply device comprising a heat exchanger for refrigerant and water, which are superposed on each other and spirally wound, the first heat exchange pipe and the second heat exchange pipe are made of the same metal material. , A second heat medium flows inside
The cross-sectional shape of the heat exchange pipe is circular or elliptical, while the cross-sectional shape of the first heat exchange pipe through which the liquid to be heat-exchanged flows is non-circular so that the two opposing surfaces are concave surfaces. A heat pump type water heater, wherein at least a part of the second heat exchange pipe is interposed in the concave surface portion of the first heat exchange pipe. 4. The heat pump type water heater according to claim 3, wherein the first heat exchange pipe and the second heat exchange pipe are made of copper or a copper alloy.