JPH0755369A - Heat exchanger - Google Patents

Abstract

PURPOSE:To improve the heat exchanging efficiency and compact the heat exchanger by a method wherein a plurality of spirally formed metallic capillary tubes, consisting of a plurality of pieces of tubes for passing first heat medium therethrough, are arranged in parallel in a heat exchanger while both ends of the capillary tubes are connected to headers to conduct second heat medium between the capillary tubes to flow therethrough. CONSTITUTION:When air flows between a plurality of capillary tubes 3a, 3b, it flows between the spiral structures of the capillary tubes 3a, 3b under the condition of turbulent flow. On the other hand, refrigerant flows through the capillary tubes 3a, 3b from an inflow port 5 and flows through the capillary tubes 3a, 3b while meandering, then, flows out of an outflow port 6. The capillary tubes 3a, 3b, arranged in parallel, are formed of a metal so as to be spiral whereby a heat transfer rate in the side of refrigerant can be improved. Further, second heat medium or the air flows between the capillary tubes 3a, 3b whereby the heat transfer area of the side of air can be increased in a small space by multi-spiral structures.

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 more particularly to a heat exchanger molded of metal capillaries used in air conditioners and the like.

[0002]

2. Description of the Related Art In recent years, as air conditioners, especially indoor units such as room air conditioners have become more compact, there has been a demand for highly efficient and compact heat exchangers. A heat exchanger generally used in an air conditioner or the like is a so-called fin-and-tube heat exchanger including heat transfer tubes and fins, and this kind of fin-and-tube heat exchanger is shown in FIG. In the figure, reference numeral 41 indicates a fin-and-tube heat exchanger, and the fin-and-tube heat exchanger 41 is composed of a plurality of fins 42.
And a heat transfer tube 43 through which the refrigerant flows are integrally connected. The fin-and-tube heat exchanger 41 causes the refrigerant to flow through the heat transfer tube 43, so that the space between the fin 42 and the heat transfer tube 43 is 4
A heat was exchanged by letting air flow through No. 4.

However, in this fin-and-tube heat exchanger 41, there is a limit to downsizing due to thinning and the like, and in order to make it more compact, for example, it is disclosed in Japanese Patent Laid-Open No. 3-67994. Such heat exchangers have been proposed. As shown in FIG. 8, the heat exchanger disclosed in Japanese Unexamined Patent Publication No. 6-67994 is configured by connecting both ends of a knitted body 52 made of a resin hollow fiber 51 to pipe end fittings 53 and a heat exchanger 54.
The heat exchanger 54 was made compact by the flexibility of the knitted body 52.

[0004]

In the above conventional heat exchanger, since the resin hollow fiber is used, the heat conductivity is lower than that of metal (copper, aluminum, etc.),
Moreover, due to problems such as pressure resistance and corrosion, there is no choice but to use water or the like as the refrigerant, and there is a problem that a decrease in heat exchange efficiency cannot be avoided.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat exchanger which can improve heat exchange efficiency and can be made compact. .

[0006]

In order to achieve the above object, a heat exchanger according to claim 1 of the present invention has a first internal heat exchanger.
A plurality of metal capillaries formed in a spiral shape are arranged in parallel with each other as one set, and both ends of the capillaries are arranged in order to allow the second heat carrier to flow between the capillaries. The part is connected to the header.

Further, the capillary tube is covered with or knitted with a knitted body in which thin resin hollow fibers or a plurality of thin resin hollow fibers are woven together.

[0008]

According to the heat exchanger having the above-mentioned structure, the plurality of capillaries arranged in parallel as one set are made of metal and are spirally formed, and the first heat transfer medium is formed in the capillaries. And the second heat medium flows between the capillaries, so that the first heat medium flows while swirling in the capillary tube, and the second heat medium flows to the outside of the capillary tube. The heat exchange efficiency is improved by the generation of the vortex flow and the turbulent flow effect.

Further, since the capillaries are covered or entangled with a knitted body in which a thin resin hollow fiber or a plurality of thin resin hollow fibers are woven together, a turbulent flow effect of the second heat medium is obtained. By improving the heat exchange area, the heat exchange efficiency can be improved and the strength of the heat exchanger can be improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a heat exchanger according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing a heat exchanger according to a first embodiment, and FIG. 2 is a partially enlarged view showing a flow of air between capillaries.

In the figure, reference numeral 1 denotes a heat exchanger, in which a header 2 is disposed on the upper and lower portions of the heat exchanger 1, and two metal ( Capillary tubes 3a and 3b made of, for example, copper or aluminum) are spirally formed as one set, and a plurality of these capillary tubes 3a and 3b are arranged in parallel as a capillary group 4. Also this capillary tube 3
Has an inner diameter of several hundred μm to several mm, and the capillaries 3a and 3b are connected to the upper header 2a and the lower header 2b by brazing or the like. A heat medium inlet 5 is formed on the side surface of the upper header 2a, and a heat medium outlet 6 is formed on the side surface of the lower header 2b.
It flows through the inside of 3b.

In the heat exchanger 1 constructed as described above, air flows between the plurality of capillaries 3a and 3b as shown by the arrow in FIG. At this time, as shown in FIG. 2, the capillary tubes 3a and 3b flow in a turbulent state between the spiral structures. Further, the refrigerant flows in through the inflow port 5, and the capillary tube 3a,
It flows out from the flow outlet 6 while meandering in 3b.

As described above, in the heat exchanger 1 according to the embodiment, a plurality of capillary tubes 3a, 3 are arranged in parallel.
Since b is made of metal, the thermal conductivity can be improved, and since the capillaries 3a and 3b are formed in a spiral shape, the refrigerant swirls in the capillaries 3a and 3b to create a turbulent state. Therefore, the heat transfer coefficient on the refrigerant side can be improved. Further, the air of the second heat medium flows between the capillaries 3a and 3b, and the heat transfer area on the air side can be greatly increased in a small space due to the multiple spiral structure. Further, in the air flowing outside the capillaries 3a and 3b, a swirling swirling component is generated along the outer wall of the tube on the center side of the spiral structure, and due to the turbulent mixing effect, the heat transfer coefficient on the air side is further improved, and heat exchange is performed. The efficiency can be improved.

In the above, the two capillary tubes 3a and 3b are replaced by one.
Although the number of the capillaries is two, the number of capillaries is not limited to two and may be two or more.

FIG. 3 is a perspective view schematically showing a main part of a second embodiment of the heat exchanger of the present invention. In FIG. 3, 11 in the drawing is a spiral or a set of two spirals. 1 shows a capillary tube molded into a shape, and the capillary tube 11 is formed by covering a knitted body 13 made of a resin hollow fiber 12.

According to the second embodiment described above, the heat exchange area of the second heat medium can be increased, and the metal capillary tube can be used rather than the heat exchanger composed only of the resin hollow fiber. By coating, the flow of the second heat medium flowing outside the capillary easily becomes turbulent, the turbulent flow mixing effect is improved, and the heat exchange efficiency can be further improved, resulting in high efficiency and compactness. Can be achieved. Further, the strength of the heat exchanger can be improved by using the metal capillary tube rather than the knitted body alone. In the above description, the knitted body 13 is formed from the resin hollow fiber 12 to cover the capillary tube 11. However, the resin hollow fiber 12 is used to cover the capillary tube 1.
It may be entangled with 1.

FIGS. 4 and 5 are front views schematically showing a third embodiment of the heat exchanger of the present invention. In FIG. 4, reference numeral 21a denotes a capillary tube group in which a plurality of spirally molded capillary tubes 22a are arranged in parallel as one or two sets, and the capillary tube group 21a is bent in an arc shape to form a header 23a. , 23b, a refrigerant inlet (not shown) is formed in one header 23a, and a refrigerant outlet 24 is formed in the other header 23b.

Further, in FIG. 5, reference numeral 21b in the drawing denotes a capillary group in which a plurality of capillary tubes 22b spirally formed as one set or two sets are arranged in parallel.
1b is bent in a meandering shape and connected to the headers 23a and 23b. One header 23a is provided with a refrigerant inlet (not shown), and the other header 23b is provided with a refrigerant outlet. 24 are formed.

According to the third embodiment described above, the capillary group 2
Since 1a and 21b are bent and formed in an arc shape or a meandering shape, the surface area of the heat exchanger can be increased and the heat exchanger can be molded in accordance with the space occupied by the heat exchanger, thereby achieving further compactness. Is possible.

6 (a) and 6 (b) are a front sectional view and a perspective view schematically showing a main part of a fourth embodiment of the heat exchanger of the present invention. In the figure, 21 indicates a capillary tube,
Heat transfer fins 32 are spirally formed on the outer surface of the capillary tube 31.

According to the fourth embodiment described above, the capillary tube 31
By forming the heat transfer fins 32 on the outer surface of the heat transfer fins, the heat exchange area on the air side can be increased, and the front edge effect of the heat transfer fins 32 can further improve the air side heat transfer coefficient. It is possible to achieve higher efficiency and compactness.

[0022]

As described above in detail, in the heat exchanger according to the present invention as defined in claim 1, since a plurality of capillaries made of metal are spirally molded, the second heat exchanger is More eddy flow of the heat medium is generated, the turbulent flow effect is further improved, and the heat transfer efficiency is improved by increasing the heat transfer area. Further, since the capillaries are covered with or knitted with a knitted body in which thin resin hollow fibers or a plurality of thin resin hollow fibers are knitted together, the turbulent flow effect of the second heat medium is improved. By increasing the heat exchange area,
The heat exchange efficiency can be improved and the strength of the heat exchanger can be improved.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a first embodiment of a heat exchanger according to the present invention.

FIG. 2 is a partially enlarged view showing a flow of air outside a capillary tube according to the first embodiment.

FIG. 3 is a perspective view of a capillary tube showing a second embodiment of the heat exchanger according to the present invention.

FIG. 4 is a front view of a capillary group showing another embodiment of the second embodiment of the heat exchanger according to the present invention.

FIG. 5 is a front view of a capillary tube group showing another embodiment of the third embodiment of the heat exchanger according to the present invention.

6 (a) and 6 (b) are a front sectional view and a perspective view of a capillary tube showing a fourth embodiment of the heat exchanger according to the present invention.

FIG. 7 is a schematic perspective view showing a conventional fin-and-tube heat exchanger.

FIG. 8 is a schematic front view showing a conventional heat exchanger.

[Explanation of symbols]

 1 Heat Exchanger 2a Upper Header 2b Lower Header 3a, 3b Capillary Tube 4 Capillary Tube Group 5 Inlet 6 Outlet

Claims (2)

[Claims] 1. A plurality of spirally formed metal capillaries, each of which has a plurality of tubes through which a first heat medium is made to flow, are arranged in parallel, and a second heat medium is provided between the capillaries. A heat exchanger, characterized in that both ends of the capillary tube are connected to a header in order to allow flow. 2. The heat according to claim 1, wherein the capillary tube is covered or entangled with a knitted body in which a thin resin hollow fiber or a plurality of thin resin hollow fibers are woven together. Exchanger.