JP4552567B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger for exchanging heat between a fluid such as water and two fluids such as a refrigerant in a device such as an air conditioner, a refrigerator, a refrigerator, and a hot water supply, particularly a heat pump type hot water heater.

  Conventionally, as this type of heat exchanger, in a heat exchanger configured to exchange heat between a primary side through which refrigerant flows and a secondary side through which water of the fluid to be heated flows, a large number of refrigerants penetrating through the wall A heat exchanger duplex in which a cylindrical refrigerant flow pipe with a flow hole is formed by aluminum extrusion, etc., the water pipe is inserted through the refrigerant flow pipe and expanded, and the refrigerant flow pipe is joined to the outer periphery of the water pipe There exists what formed the pipe | tube (for example, refer patent document 1).

13 to 14 show a conventional heat exchanger described in Patent Document 1. FIG. As shown in the figure, the heat exchanger main body 100 includes a water flow pipe 101 through which water flows and a cylindrical refrigerant flow pipe 103 in which a large number of refrigerant flow holes 102 having a small diameter are arranged on the outer peripheral side of the water flow pipe 101. And
The water flow pipe 101 is joined to the refrigerant flow pipe 103 by pipe expansion processing.

  The operation of the heat exchanger configured as described above will be described below.

  Water flows through the inside of the water flow pipe 101 and the refrigerant flows through the large number of refrigerant flow holes 102 of the cylindrical refrigerant flow pipe 103 in opposite directions, and heat is exchanged at the junction between the water flow pipe 101 and the refrigerant flow pipe 103.

Here, the heat transfer coefficient of the refrigerant can be increased by reducing the diameter of the refrigerant flow hole 102 of the refrigerant flow pipe 103, and a sufficient contact area is ensured between the refrigerant flow pipe 103 and the water flow pipe 101. High heat exchange efficiency is obtained.
JP 2002-213895 A

  However, in the above-described conventional configuration, heat is released to the outside of the refrigerant circulation pipe 103, and in order to improve the heat exchange performance of the water heat exchanger 100, the outside of the refrigerant circulation pipe 103 is subjected to heat transfer such as a heat insulating material. It is necessary to cover with a suppressing member. Therefore, the water heat exchanger alone can improve the heat exchange performance with a simple structure, and even if it is easy to manufacture, easy to transport, and reduces costs, peripheral members such as heat insulating materials are indispensable. When incorporating into a product such as a container, there is a problem that it is not possible to achieve sufficient compactness, weight reduction, and reduction of peripheral members such as a heat insulating material.

  Moreover, since mineral components, such as calcium (Ca), are contained in tap water, when it heats and the temperature of water rises, the solubility of calcium will fall and the calcium dissolved in water will precipitate.

  And when the precipitated calcium adheres to the inner wall of the water flow pipe 101, the water flow pipe 101 is clogged and the heat exchanger does not function. In contrast, it is necessary to set the pipe diameter and the inner diameter of the cylindrical refrigerant flow pipe 103 large only on the high temperature side of the water flow pipe 101 where calcium is deposited, but the pipe diameter of the refrigerant flow pipe 103 is partially varied. This is difficult with extrusion.

  Therefore, it is necessary to set the pipe diameter of the water flow pipe 101 and the inner diameter of the refrigerant flow pipe 103 to be large as a whole in anticipation of the amount of adhered (deposited) calcium. There was a problem that the heat transfer rate was reduced and the heat exchange efficiency was reduced.

  The present invention solves the above-described conventional problems, and can achieve sufficient compactness, weight reduction, and reduction of peripheral members such as heat insulating materials, and precipitation of mineral components such as calcium (Ca) of tap water only on the high temperature side. It aims at providing the heat exchanger which suppressed the function stop of a heat exchanger and suppressed the fall of the heat transfer rate by the flow velocity reduction of water as much as possible.

In order to solve the above-described conventional problems, the heat exchanger of the present invention is provided with a plurality of multi-hole pipes having a plurality of flow paths through which a refrigerant flows, and between the circumferential directions of the multi-hole pipes. A plurality of atypical pipes through which water flows facing the refrigerant are installed, the outer wall of the multi-hole pipe and the outer wall of the atypical pipe are in contact with each other, and the flow cross-sectional area on the outflow side of the atypical pipe is the inflow of the atypical pipe The outer wall of the atypical pipe that is in contact with the refrigerant inflow side of the multi-hole pipe is made a convex surface, and the contact with the outer wall of the multi-hole pipe facing the surface is reduced .

As a result, heat from the refrigerant can be transferred from almost the entire multi-hole pipe to the water flowing inside the atypical pipe in contact with the multi-hole pipe, and a sufficient contact area between the refrigerant flow path and the water flow path The heat insulating material that is attached to the heat exchanger can be simplified by securing high heat exchange efficiency, and the flow of the multi-hole tube is increased by expanding only the cross-sectional area of the outflow part of the atypical tube through which water flows. Even if the refrigerant flows through the channel and exchanges heat with water, the water becomes a high-temperature part, and even if calcium contained in water (especially tap water) precipitates and adheres to the wall of the irregular pipe in the outflow part, the water flow is sealed. There is no stopping. In addition, since the channel cross-sectional area on the water inflow side of the irregular pipe is not enlarged, the flow rate of the water is not reduced and the heat transfer coefficient with the irregular pipe is not lowered.

Also, the outer wall of the atypical tube that contacts the refrigerant inflow side of the multi-hole tube has a convex surface, and by reducing the contact with the outer wall of the opposed multi-hole tube, the thermal resistance on the outflow side of the atypical tube where water becomes hot To reduce the heat exchange performance on the outflow side of the deformed pipe to partially suppress calcium adhesion, and to reduce the expansion of the cross-sectional area of the flow path on the outflow side of the deformed pipe as much as possible, Even if it adheres, it can suppress stopping a heat exchange function, without sealing the flow of water.

  The heat exchanger of the present invention does not have a leak detection means that requires a complicated manufacturing process in a pipe through which water flows, and can achieve high heat exchange efficiency with a simple structure, reducing weight and reducing peripheral members such as heat insulating materials. The flow exchange cross section on the outflow side of only the atypical pipe through which water flows can be changed, and the heat exchange function can be stopped without sealing the flow of water even if calcium deposits and adheres to the pipe wall. In addition, since the flow rate of water at the inflow portion is not decreased and the heat transfer coefficient with the inner pipe is not decreased, the heat exchanger as a whole can be suppressed from decreasing the heat transfer coefficient as much as possible.

In the first aspect of the present invention, a plurality of multi-hole pipes having a plurality of flow paths through which a refrigerant flows are arranged radially, and water flows in a circumferential direction of the multi-hole pipe so as to face the refrigerant. A plurality of modified tubes are installed, the outer wall of the multi-hole tube and the outer wall of the modified tube are in contact with each other, and the flow passage cross-sectional area on the outflow side of the modified tube is larger than the flow passage cross-sectional area on the inflow side of the modified tube. The outer wall of the atypical tube that contacts the refrigerant inflow side of the multi-hole tube is formed into a convex surface, and the contact with the outer wall of the multi-hole tube facing the surface is reduced. Heat can be transferred from almost the whole to the water flowing inside the atypical tube that contacts the multi-hole tube, ensuring a sufficient contact area between the refrigerant flow path and the water flow path to obtain high heat exchange efficiency The heat insulating material attached to the heat exchanger can be simplified, and only the cross-sectional area of the outflow part of the atypical pipe through which water flows can be enlarged. By suppressing the heat exchange function without sealing the flow of water even if calcium adheres to the tube wall of the atypical tube on the outflow side where water becomes hot and calcium is likely to precipitate, Furthermore, since the heat flow rate with the inner pipe is not lowered without decreasing the flow rate of water in the inflow portion of the atypical pipe, it is possible to suppress the reduction of the heat transfer coefficient as much as possible as the entire heat exchanger.

In addition, the outer wall of the irregular tube that contacts the refrigerant inflow side of the multi-hole tube has a convex surface, and the contact with the outer wall of the opposed multi-hole tube reduces the heat on the outflow side of the irregular tube where water becomes hot. Increase the resistance to partially reduce the heat exchange performance on the outflow side of the deformed pipe to suppress the adhesion of calcium, and reduce the expansion of the cross-sectional area of the flow path on the outflow side of the deformed pipe as much as possible to reduce the calcium on the tube wall of the deformed pipe Even if adhering, it can suppress stopping a heat exchange function, without sealing the flow of water.

The invention according to claim 2 can obtain high heat pump efficiency when used as a water / refrigerant heat exchanger for a heat pump water heater by using carbon dioxide as the refrigerant of the invention according to claim 1. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The present invention is not limited to the embodiment.

(Embodiment 1)
FIG. 1 is a front view in the tube axis direction of the heat exchanger according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 3 is a cross-sectional view taken along line BB in FIG. FIG. 4 is a cross-sectional view perpendicular to the axial direction of the tube group and the modified tube of another heat exchanger of the same embodiment.

  1 to 3, the heat exchanger 1 is provided with four radial multi-hole tubes 2 in which a plurality of flow paths 3 through which carbon dioxide flows as a refrigerant are arranged in a row. Furthermore, there is an atypical tube 4 disposed between the circumferential directions of the multi-hole tube 2, and water flows in opposition to the refrigerant. The outer wall 5 of the multi-hole tube 2 and the outer wall 6 of the modified tube 4 are in contact so as to conduct heat directly. The multi-hole tube 2 and the variant tube 4 are copper drawn products having good corrosion resistance and thermal conductivity. Further, the cross-sectional area of the outflow side 4a of the variant pipe 4 is larger than the cross-sectional area of the inflow side 4b.

  In FIG. 4, there is a tube group 7 in which four tubes 8 through which carbon dioxide flows as a refrigerant are arranged in parallel, and four tubes 8 are arranged radially. The outer wall 7a of the tube 7 of the tube group 8 and the outer wall 6 of the modified tube 4 are in contact with each other so as to conduct heat directly. The tube 7 is a round tube, which is a copper drawn product with good corrosion resistance and thermal conductivity.

  The operation of the heat exchanger configured as described above will be described below.

  1 to 3, carbon dioxide flows inside the plurality of flow paths 3 of the multi-hole tube 2 and water flows as fluids inside the variant tube 4, respectively. Water and carbon dioxide exchange heat through the outer wall 6 of the tube 4.

  Here, the heat from the carbon dioxide can be transferred from substantially the entire outer wall 5 of the multi-hole tube 2 to the water flowing in the tube of the modified tube 4 in contact with the multi-hole tube, and the heat exchange performance can be improved. . A heat insulating material (not shown) attached to the heat exchanger 1 can also be simplified, and when incorporated in a product such as a heat pump water heater, sufficient compactness and weight reduction can be achieved.

  Furthermore, by expanding the cross-sectional area of the outflow side 4a of the variant pipe 4 through which water flows from the cross-sectional area of the inflow side 4b, carbon dioxide flows through the multi-hole pipe 2 and the irregular pipe 4 Even if water contained in water (especially tap water) precipitates and adheres to the tube wall 6 of the deformed tube 4 of the outflow part 4a, the water is sealed off by heat exchange with water. There is no. Further, since the cross-sectional area of the flow path 4b on the water inflow side 4b of the variant pipe 4 does not increase, the flow rate of water is not reduced and the heat transfer coefficient with the variant pipe 4 is not lowered. Accordingly, the heat exchanger main body 1 as a whole can be prevented from reducing the heat exchange performance as much as possible.

  In FIG. 4, carbon dioxide flows through the four tubes 8 of the tube group 7 and water flows through the modified tube 4 as fluids. The outer wall 8 a of the tube 8 and the outer wall of the modified tube 4 Water and carbon dioxide exchange heat through 6.

  Here, heat from carbon dioxide can be transferred from almost the entire tube 8 of the tube group 7 to the water flowing inside the atypical tube 4 in contact with the tube group 7, and heat exchange performance can be improved. The heat insulating material attached to the heat exchanger 1 can also be simplified, and it can be made sufficiently compact and lightweight when incorporated in a product such as a heat pump water heater. Furthermore, the flow path through which carbon dioxide flows is compared to a multi-hole tube, It can be made into a round tube that is easy to mass-produce.

  In the embodiment of the present invention, the multi-hole tube 2, the tube group 7 of the tube 8, and the atypical tube 4 through which water circulates are straight tubes, but the same effect can be obtained when the shape is curved or coiled. can get.

The material of the multi-hole pipe 2 through which the refrigerant flows, the tube group 7 of the pipe 8 and the modified pipe 4 through which water flows is usually made of copper, but the same applies to brass, SUS, iron with corrosion resistance, aluminum alloy, etc. Effects can be obtained. The tube group 7 of the multi-hole tube 2 and the tube 8 through which the refrigerant flows is preferably made of a material having good heat conductivity (for example, copper or aluminum), and the modified tube 4 is preferably a material having good corrosion resistance (for example, stainless steel). The one made with is good.

  In the embodiment of the present invention, carbon dioxide is used as the refrigerant flowing through the multi-hole pipe 2 and the pipe 8. However, the present invention is not limited to this, and other high-pressure refrigerants such as R410A and R32, water, and a temperature difference. The same effect can be obtained even if it is used for heat exchange between the same fluids.

(Embodiment 2)
FIG. 5 is a front view in the tube axis direction of the heat exchanger according to Embodiment 2 of the present invention. 6 is a cross-sectional view taken along the line CC of FIG. In addition, about the same structure as the above-mentioned embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  5 to 6, the modified pipe 9 has a convex surface on the outer wall 10 in contact with the carbon dioxide inflow side 2 a of the multi-hole tube 2, and the outflow side 9 a of the modified pipe 9 in accordance with the convex outer wall 10. By making the inner wall 11 convex to the side in contact with the multi-hole tube 2, the cross-sectional area of the outflow side 9a of the modified tube 9 is enlarged.

  About the heat exchanger 1 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In the heat exchanger 1, carbon dioxide flows through the flow path 3 of the multi-hole tube 2 and water flows inside the modified tube 9 as fluids, so that the outer wall 5 of the multi-hole tube 2 and the outer wall 10 of the modified tube 9 pass through each other. Through this, water and carbon dioxide exchange heat.

  Here, the outer wall 10 of the atypical tube 9 in contact with the carbon dioxide inflow side 2a of the multi-hole tube 2 is formed as a convex surface, and the contact with the outer wall 5 of the opposed multi-hole tube 2 is reduced, so that the water becomes hot. The heat resistance of only the outflow side 9a of the modified tube 9 can be partially reduced by increasing the heat resistance of the outflow side 9a of the modified tube 9 to suppress the adhesion of calcium, and the flow path of the outflow side 9a of the modified tube 9 Even if calcium adheres to the inner wall 11 of the modified tube 9 by minimizing the expansion of the cross-sectional area, it is possible to suppress the heat exchange function from being stopped without sealing the flow of water.

(Embodiment 3)
FIG. 7 is a front view in the tube axis direction of the heat exchanger according to Embodiment 3 of the present invention. FIG. 8 is a perspective view of a main part from the direction A in FIG. FIG. 9 is a perspective view of a main part from the direction B in FIG. In addition, about the same structure as the above-mentioned embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  In FIG. 7 to FIG. 9, four multi-hole pipes 2 arranged radially on the carbon dioxide outflow side 2c and four inflow pipes 4c arranged in the circumferential direction are arranged radially. It is twisted around the approximate center.

  About the heat exchanger 1 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In the heat exchanger 1, carbon dioxide flows through the flow path 3 of the multi-hole tube 2, and water inside the modified tube 4 flows as a fluid, respectively, so that the outer wall 5 of the multi-hole tube 2 and the outer wall 6 of the modified tube 4 pass through. Through this, water and carbon dioxide exchange heat.

Here, the outflow side 2c of the multi-hole tube 2 and the inflow side 4c of the variant tube 4 are connected by twisting the outflow side 2c of the carbon dioxide tube 2 and the inflow side 4c of the variant tube 4 about the radial center. The heat exchange performance of the carbon dioxide outflow side 2c of the multi-hole tube 2 and the water inflow side 4c of the modified tube 4 is high even without welding, brazing, soldering, constraining material, etc. Therefore, the heat exchanger 1 as a whole can suppress the decrease in heat transfer coefficient as much as possible.

(Embodiment 4)
FIG. 10 is a front view in the tube axis direction of the heat exchanger according to Embodiment 4 of the present invention. FIG. 11 is a perspective view of a main part from the direction C in FIG. 12 is a perspective view of a main part from the direction D in FIG. In addition, about the same structure as the above-mentioned embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  In FIGS. 10 to 12, four multi-hole pipes 2 arranged radially and four modified pipes 4 arranged in the circumferential direction of the multi-hole pipe 2 are twisted around a substantially radial center, The twist pitch is small on the carbon dioxide outflow side 2d of the multi-hole tube 2, and the twist pitch is large on the inflow side 2e.

  About the heat exchanger 1 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In the heat exchanger 1, carbon dioxide flows through the flow path 3 of the multi-hole tube 2, and water inside the modified tube 4 flows as a fluid, respectively, so that the outer wall 5 of the multi-hole tube 2 and the outer wall 6 of the modified tube 4 pass through. Through this, water and carbon dioxide exchange heat.

  Here, since the twist pitch is small on the carbon dioxide outflow side 2d of the multi-hole tube 2, the close contact degree between the multi-hole tube 2 and the inflow side 4d of the irregular tube 4 is high, and the closely adhered multi-hole tube 2 and irregular tube Since the length of 4 is longer than the radial central axis, the heat exchange performance can be improved. On the carbon dioxide inflow side 2e of the multi-hole tube 2, the multi-hole tube 2 and the outflow side 4e of the modified tube 4 are connected to each other. The degree of adhesion is moderate and can be restrained, and heat conduction due to contact between the multi-hole tube 2 and the modified tube 4 can be suppressed, and the heat exchange performance can be partially reduced to suppress the adhesion of calcium. Furthermore, the entire heat exchanger 1 can be restrained without welding, brazing, soldering, restraining materials, or the like.

  As described above, the heat exchanger according to the present invention can transfer heat from almost the entire multi-hole tube or tube group serving as a heat source to the fluid flowing inside the multi-hole tube or the atypical tube in contact with the tube group. The heat insulating material attached to the heat exchanger can also be simplified, making it sufficiently compact and lightweight when incorporated into products, and heat exchange by precipitation of mineral components such as calcium (Ca) in tap water only on the high temperature side It is possible to suppress the shutdown of the heater and to suppress the reduction of the heat transfer coefficient due to the decrease of the water flow rate as much as possible, the heat pump water heater, the multifunction device equipment with household and commercial air conditioners, the fuel cell It can also be applied to uses such as a hot water supply system.

The front view of the pipe-axis direction of the heat exchanger in Embodiment 1 of this invention AA sectional view of FIG. BB sectional view of FIG. Sectional drawing perpendicular | vertical to the axial direction of the tube group of another heat exchanger of the same embodiment, and a deformed tube The front view of the pipe-axis direction of the heat exchanger in Embodiment 2 of this invention CC sectional view of FIG. Front view of tube direction of heat exchanger in embodiment 3 of the present invention The principal part perspective view from the A direction of FIG. 7 is a perspective view of the main part from the direction B in FIG. The front view of the pipe-axis direction of the heat exchanger in Embodiment 4 of this invention The principal part perspective view from the C direction of FIG. The principal part perspective view from the D direction of FIG. Structure of conventional heat exchanger Structure of another conventional heat exchanger

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Multi-hole pipe 2a, 2e Carbon dioxide inflow side 2c, 2d Carbon dioxide outflow side 3 Channel 4, 9 Atypical pipe 4a, 4e, 9a Outflow side (of atypical pipe)
4b, 4c, 4d, 9b Inflow side (atypical tube)
5 outer wall (of multi-hole tube 2)
6 Outer wall (Atypical pipe 4)
7 Tube group 8 Tube 10 Convex outer wall (of atypical tube 4)

Claims (2)

A plurality of multi-hole pipes having a plurality of flow paths through which the refrigerant flows are arranged radially, and a plurality of atypical pipes through which water flows in the circumferential direction of the multi-hole pipes are arranged opposite to the refrigerant, The outer wall of the multi-hole tube and the outer wall of the irregular tube are in contact with each other, the flow passage cross-sectional area on the outflow side of the irregular tube is expanded from the cross-sectional area on the inflow side of the irregular tube, and the refrigerant inflow side of the multi-hole tube The heat exchanger is characterized in that the outer wall of the atypical tube in contact with the surface is convex and the contact with the outer wall of the opposed multi-hole tube is reduced . The heat exchanger according to claim 1, wherein the refrigerant is carbon dioxide.

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