JP2006234254A - Heat exchanger and heat pump type hot water supply device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger having improved reliability while maintaining good heat exchanging efficiency, and to provide a heat pump type hot water supply device using the same. <P>SOLUTION: The heat exchanger 1 comprises first heat exchanger tubes 2 of narrow shape each having a first flow path 2A inside in which first fluid flows, and second heat exchanger tubes 3 of hollow flat shape each having a second flow path 3A inside in which second fluid flows. The second heat exchanger tubes 3 are wound in spiral or scroll shape, and the first heat exchanger tubes 2 are arranged in numbers side by side, held in a heat conductive relationship between the second heat exchanger tubes 3, 3 of hollow flat shape, and each formed of the same material as that of the second heat exchanger tube 3. This construction is applied to the heat pump type hot water supply device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat exchanger and a heat pump type hot water supply device using the heat exchanger, and in particular, different from a refrigerant-to-water heat exchanger used in a hot water supply device or a hot water supply / heating device that generates hot water using a heat pump circuit. The present invention relates to a heat exchanger for exchanging heat between various types of fluids and a heat pump type hot water supply apparatus using the heat exchanger.

  Conventionally, as this type of heat exchanger, a heat exchanger as shown in FIG. 5 has been proposed. This conventional configuration will be described with reference to FIG. 5 (see, for example, Patent Document 1 and Patent Document 2).

The heat exchanger 50 is used, for example, in a so-called heat pump type hot water supply apparatus that heats hot water using the heat of condensation of carbon dioxide refrigerant or the like. And the aluminum 1st heat exchanger tube 51 in which the several 1st flow path through which a refrigerant | coolant flows inside was arranged in parallel, and the hollow flat shape and copper made in which the 2nd flow path through which the water for hot water supply flows was formed inside The second heat transfer tubes 52 are configured to overlap with each other and be wound spirally.
JP 2003-42686 A

  However, the conventional configuration has the following problems. For example, since the materials of the first heat transfer tube and the second heat transfer tube are different, there is a difficulty in integrally connecting them by brazing. That is, in the brazing, the brazing connection between the two heat transfer tubes cannot be performed well. Moreover, it is inferior to heat transfer property only by making both heat exchanger tubes contact. Furthermore, both heat transfer tubes are made of different metals, and it is necessary to subject the surface of the first heat transfer tube to the same material as the second heat transfer tube from the viewpoint of preventing the occurrence of electrolytic corrosion.

  An object of the present invention is to solve the above-mentioned conventional problems, and to provide a heat exchanger excellent in reliability while maintaining good heat exchange efficiency and a heat pump hot water supply apparatus using the heat exchanger.

  In order to solve the conventional problem, the heat exchanger according to the first aspect of the present invention includes a first tubular heat pipe having a first flow path through which a first fluid flows, and a second fluid. A hollow flat second heat transfer tube having a second flow path inside, and the second heat transfer tube has a configuration wound in a spiral shape or a spiral shape, and a plurality of the first heat transfer tubes are provided. Are arranged side by side, arranged in a heat conductive relationship between the hollow flat second heat transfer tubes, and formed of the same material as the second heat transfer tubes. .

  A heat exchanger according to a second aspect of the present invention is the heat exchanger according to the first aspect, wherein the plurality of first heat transfer tubes and the second heat transfer tubes are integrally coupled by a brazing process. It is characterized by that.

  The heat exchanger according to a third aspect of the present invention is the heat exchanger according to the second aspect, wherein the brazing material for brazing is formed of the same material as the first and second heat transfer tubes. To do.

  A heat pump hot water supply apparatus according to a fourth aspect of the present invention includes a heat pump circuit including at least a compressor, a heat radiator, an expansion valve, and an evaporator, and the heat radiator is any one of the first to third aspects. And the water as the second fluid is heated with the refrigerant as the first fluid.

  A heat pump type hot water supply apparatus according to a fifth aspect of the present invention is the heat pump type hot water supply apparatus according to the fourth aspect, wherein the refrigerant as the first fluid is a natural refrigerant containing carbon dioxide, and the high pressure of the natural refrigerant is critical. It is characterized by being above the pressure.

  According to the first aspect of the present invention, a hollow first flat heat transfer tube having a first flow path through which the first fluid flows and a hollow flat shape having a second flow path through which the second fluid flows. The second heat transfer tube has a configuration wound in a spiral shape or a spiral shape, and a plurality of the first heat transfer tubes are arranged side by side to form the hollow flat shape. Since the second heat transfer tube is disposed in a heat conduction relationship and is formed of the same material as that of the second heat transfer tube, it is possible to satisfactorily combine by brazing. The high heat of the multiple first heat transfer tubes is efficiently transferred to the heat exchange fluid flowing in the second heat transfer tubes, maintaining good heat exchange efficiency and eliminating the need for countermeasures against electric corrosion and reliability. An excellent heat exchanger can be provided.

  Further, by using the heat exchanger of the present invention that is excellent in reliability while maintaining good heat exchange efficiency, it is possible to achieve higher efficiency and improved reliability of the heat pump water heater.

  The invention described in claim 1 aims to provide a heat exchanger that is excellent in reliability while maintaining good heat exchange efficiency, and has a tubular shape having a first flow path through which the first fluid flows. A first heat transfer tube and a hollow flat second heat transfer tube having a second flow path through which the second fluid flows are provided, and the second heat transfer tube has a configuration wound in a spiral shape or a spiral shape. A plurality of the first heat transfer tubes are arranged side by side, arranged in a heat conductive relationship between the hollow flat second heat transfer tubes, and made of the same material as the second heat transfer tubes. It was realized by forming.

  Invention of Claim 4 is a heat pump type hot water supply apparatus which heats water with a refrigerant | coolant, The heat exchanger of Claims 1-3 is comprised from a compressor, a radiator, an expansion valve, and an evaporator at least. The heat exchanger according to any one of claims 1 to 3 is used as the radiator, and water as the second fluid is heated with a refrigerant as the first fluid. By using the heat exchanger of the present embodiment that is excellent in reliability while maintaining good heat exchange efficiency, it is possible to achieve high efficiency and improved reliability of the entire heat pump water heater.

  Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a heat exchanger according to a first embodiment of the present invention, and FIG.

  1 and 2, reference numeral 1 denotes a heat exchanger. The heat exchanger 1 has a plurality of (in the embodiment) each having a first flow path 2 </ b> A through which a first fluid (for example, a high-temperature and high-pressure refrigerant) flows. (3) thin tubular first heat transfer tubes 2, 2, 2 and a hollow flat second heat transfer tube 3 having a second flow path 3A in which a second fluid (for example, low temperature and low pressure water) flows. The second heat transfer tube 3 and a plurality (three in the embodiment) of thin first heat transfer tubes 2, 2, 2 have a configuration wound spirally.

  The first heat transfer tubes 2 are arranged side by side in a state where a plurality of the heat transfer tubes 2 are in contact with each other, and heat is generated between the upper hollow flat second heat transfer tube 3 and the lower hollow flat second heat transfer tube 3. They are placed in a conductive relationship. As shown in FIG. 2, the plurality of first heat transfer tubes 2 are each composed of a thin copper pipe having an outer diameter D of about 4 to 7 mm.

The second heat transfer tube 3 is obtained by deforming a copper pipe having a large outer diameter about 2 to 4 times the outer diameter D of the first heat transfer tube 2 into a hollow flat shape. As shown in FIG. 2, the plurality of first heat transfer tubes 2 arranged side by side are configured to fit within a lateral width dimension S of the second heat transfer tube 3. The heat transfer tube 2 and the second heat transfer tube 3 are integrally coupled by a copper brazing process using a copper brazing material. Reference numeral 5 denotes a brazing material treatment film formed by the copper brazing treatment. The material of the brazing material treatment film 5 is mainly composed of copper of the same material as the first heat transfer tube 2 and the second heat transfer tube 3.

  The first flow path 2A through which the first fluid (for example, carbon dioxide refrigerant) flows is in communication with each other via the branching tool 6 and the joining tool 7, and is parallel to the refrigerant flow path R of the heat pump circuit 15 described later. A plurality of connected fluid passages are formed.

  The operation of the heat exchanger 1 configured as described above will be described below. In the plurality of first heat transfer tubes 2 and one second heat transfer tube 3, the first flow path 2A has a high-pressure side One fluid is circulated through the second flow path 3A through the second fluid on the low pressure side. And the heat exchanger 1 is utilized for the refrigerant | coolant vs. water heat exchanger of the heat pump type hot water supply apparatus which heats hot water using the condensation heat, sensible heat, etc. of a compressed refrigerant as shown in FIG. .

  For example, the high-pressure first fluid is a natural refrigerant containing carbon dioxide sent from a compressor such as a two-stage compressor, and the low-pressure second fluid is hot water supply water.

  As shown in FIG. 3, the above-described heat pump water heater generally includes a compressor 10, a heat exchanger 1 as a radiator, an expansion valve 11, capillary tubes 12 and 12, an evaporator 13 that collects atmospheric heat and the like, and The heat pump circuit 15 is connected to the accumulator 14 and the like, and the hot water storage tank 16, the water circulation pump 17, and the hot water storage circuit 18 are connected to the heat exchanger 1.

  Reference numeral 20A denotes a bypass opening / closing valve provided in the middle of the bypass circuit 20 that bypasses the heat exchanger 1, and this opening / closing valve 20A is constituted by an electromagnetic opening / closing valve, and is opened during the defrosting operation of the evaporator 13. A part of the high-temperature and high-pressure gas refrigerant that is operated and discharged from the compressor 10 flows directly to the evaporator 13 for defrosting.

  When heating hot water using such a heat pump type hot water supply device, first, in the evaporator 13, atmospheric heat is collected by a blower fan (not shown), and the refrigerant flowing in the evaporator 13 is converted into evaporated gas. Let This refrigerant is sucked into the compressor 10 via the accumulator 14, is compressed in two stages, is divided into a plurality of parallel upstream of the heat exchanger 10 as high-temperature and high-pressure refrigerant, and is sent to the first flow paths 2A and 2A.

  On the other hand, the hot water supply water in the lower part of the hot water storage tank 16 is conveyed by driving the water circulation pump 17 and flows into the second flow path 3A of the heat exchanger 1. The low-temperature and low-pressure water flowing into the second flow path 3A can be made excellent in heat exchange performance when flowing in the direction opposite to the flow of the refrigerant (to make it a counterflow).

  At this time, the high-temperature and high-pressure refrigerant flowing through the plurality of first flow paths 2A and 2A passes through the first heat transfer tubes 2 and 2 and low-temperature and low-pressure water flowing through the second flow paths 3A and 3A positioned above and below them. And heat exchange. The low-temperature hot water supply water receives heat from the high-temperature refrigerant while flowing through the second flow path 3 </ b> A, becomes high-temperature hot water, and returns to the upper part of the hot water storage tank 13.

  The refrigerant radiated by the heat exchanger 1 is decompressed by the expansion valve 11, further decompressed by the capillary tubes 12, 12, and flows into the evaporator 13. The refrigerant that has flowed into the evaporator 13 again absorbs heat from the atmospheric heat and is sent to the compressor 13 again.

  Examples of the refrigerant used in the heat pump water heater include natural refrigerants such as carbon dioxide refrigerant. Other examples include chlorofluorocarbon refrigerants, hydrocarbon refrigerants such as propane and butane, etc. In order to raise the temperature of water for hot water storage to a high temperature of about 90 ° C., a natural refrigerant containing carbon dioxide refrigerant is used. Is preferred.

  According to the present embodiment, the first tubular heat transfer pipe 2 having the first flow path 2A through which the first fluid flows and the hollow flat first shape having the second flow path 3A through which the second fluid flows. 2 heat transfer tubes 3, and the second heat transfer tube 3 is configured to be spirally wound, and a plurality of the first heat transfer tubes 2, 2, 2 are arranged side by side and are positioned vertically By arranging the first heat transfer tube 2 and the second heat transfer tube 3 of copper of the same material, the flat heat transfer tubes 3 and 3 are sandwiched between the heat transfer relationships. The heat pipes 2 and 3 can be connected to each other well by copper brazing of the same material.

  In addition, the high heat of the high-temperature and high-pressure refrigerant flowing through the plurality of first flow paths 2A is efficiently transferred to the hot water flowing through the second flow paths 3A and 3A, and the heat exchange efficiency can be maintained well. It is not necessary to cope with the electric corrosion which is a concern when the heat transfer tubes 2 and 3 are made of different metals, and the heat exchanger 1 having excellent reliability can be obtained.

  Further, the plurality of first heat transfer tubes 2, 2, 2 and the second heat transfer tube 3 are integrally coupled by the brazing process using copper brazing, so that they are spirally wound into a cylindrical shape There is no need to press and fix the top and bottom of the heat exchanger 1 using a pressing plate, and the heat transfer property is also better than the contact between the heat transfer tubes 2 and 3 by pressing.

  In addition, since the brazing material for brazing is formed of the same material as the plurality of first heat transfer tubes 2 and one second heat transfer tube 3, the bonding strength by the brazing processing is increased.

  Furthermore, the heat exchanger 1 of the present embodiment is used as a radiator of a heat pump circuit including at least a compressor, a radiator, an expansion valve, and an evaporator, and the water of the second fluid is heated by the refrigerant of the first fluid. By using the heat exchanger of the present invention that is excellent in reliability while maintaining good heat exchange efficiency, it is possible to realize high efficiency and improved reliability of the heat pump type hot water supply apparatus. In particular, if the refrigerant as the first fluid is a natural refrigerant containing oxygen dioxide, and the high pressure of the natural refrigerant is equal to or higher than the critical pressure, the refrigerant as the first fluid flowing through the heat exchanger 1 has a two-stage pressure. Since the compressor 10 is pressurized above the critical pressure, it does not condense even if the temperature is lowered due to heat being taken away by the water as the second fluid, and the refrigerant and water are converted into the refrigerant and water over the entire region of the heat exchanger 1. It becomes easy to form a temperature difference, hot water having higher temperature is obtained, and heat exchange efficiency is improved.

  FIG. 4 is an enlarged cross-sectional view of the main part of the heat exchanger 30 according to the second embodiment of the present invention. The overall configuration and operation of the heat exchanger according to the present embodiment are the same as those of the heat exchanger 10 shown in FIGS. The detailed description thereof will be omitted.

  The second embodiment is different from the first embodiment in that a plurality of (three in the embodiment) narrow tubes each having a first flow path 2A through which a first fluid (for example, a high-temperature and high-pressure refrigerant) flows. The first heat transfer tubes 2, 2, 2 and the hollow flat second heat transfer tube 3 having a second flow path 3 </ b> A through which a second fluid (for example, low temperature and low pressure water) flows are of a flat plate type. It is the point which has the structure wound by the spiral shape. That is, in the heat exchanger 30 of the second embodiment, the entire shape thereof is formed into a circular flat plate type or an elliptic flat plate type having a spiral shape.

  According to this embodiment, the overall shape is flat and flat, and when the heat exchanger is installed, for example, along the wall surface such as the side wall or bottom wall of the exterior body that forms the outline of the water heater. Therefore, it is possible to provide a heat exchanger that can be compactly accommodated.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are made within the scope of the gist of the present invention described in the claims. It is possible. For example, in each of the above-described embodiments, an example in which the heat exchanger is applied to a heat pump type hot water supply apparatus has been described. However, the heat exchanger may be applied to a heat pump type hot water supply and heating apparatus to which a hot water heating function is added.

It is a side view of the heat exchanger in Example 1 of this invention. It is a principal part expanded sectional view of the heat exchanger in Example 1 of this invention. It is a block diagram of the heat pump hot-water supply apparatus using the heat exchanger in Example 1 of this invention. It is a principal part expanded sectional view of the heat exchanger in Example 2 of this invention. It is a principal part expanded sectional view of the conventional heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 1st heat exchanger tube 2A 1st flow path 3 2nd heat exchanger tube 3A 2nd flow path 10 Compressor 11 Expansion valve 13 Evaporator 15 Heat pump circuit 20 Heat exchanger

Claims (5)

  A thin tubular first heat transfer tube having a first flow path through which the first fluid flows and a hollow flat second heat transfer tube having a second flow path through which the second fluid flows are provided. The heat transfer tube has a configuration wound in a spiral shape or a spiral shape, and a plurality of the first heat transfer tubes are arranged side by side and sandwiched in a heat conduction relationship between the hollow flat second heat transfer tubes. And the heat exchanger is formed of the same material as the second heat transfer tube.   The heat exchanger according to claim 1, wherein the plurality of first heat transfer tubes and the second heat transfer tubes are integrally coupled by brazing.   The heat exchanger according to claim 2, wherein the brazing material for the brazing process is formed of the same material as the first and second heat transfer tubes.   A heat pump circuit including at least a compressor, a radiator, an expansion valve, and an evaporator is provided, the heat exchanger according to any one of claims 1 to 3 is used as the radiator, and the first fluid A heat pump type hot water supply apparatus that heats water as the second fluid with the refrigerant.   The heat pump hot water supply device according to claim 4, wherein the refrigerant as the first fluid is a natural refrigerant containing carbon dioxide, and a high pressure of the natural refrigerant is set to a critical pressure or more.

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