KR20110004738A - Fin tube heat exchanger - Google Patents

Abstract

PURPOSE: A fin-tube heat exchanger is provided to ensure smooth heat exchange at the fins located in the downstream side of a pipe because bent surfaces gather the flow of fluid to the downstream side. CONSTITUTION: A fin-tube heat exchanger(100) comprises a pipe(10) in which fluid flows and a plurality of fins(20) formed of metal plates and vertically arranged on the pipe. Heat exchange is made between the fluid flowing inside the pipe and the fluid passing by the outside of the fins. Each fin has a first bent surface(30) on an edge and a second bent surface(40) which is separate from the first bent surface.

Description

Fin Tube Heat Exchanger {FIN TUBE HEAT EXCHANGER}

The present invention relates to a fin tube heat exchanger, and more particularly, to the shape of the heat radiation fins attached to the tube of the heat exchanger.

Heat exchangers are used in a wide range of fields such as refrigerators, air conditioners or automobiles, and in the field of using heat energy, the performance of heat exchangers is an important factor affecting the price, performance, efficiency, and durability of machines equipped with heat exchangers.

By the way, heat exchanger that transmits heat to fluid among heat exchangers uses heat radiating fin to reduce heat resistance because main heat resistance (element that hinders heat flow) is outside the tube. Is attached, and fluid flows around the heat dissipation fins so that the fluid inside the tube and the fluid around the heat dissipation fins exchange heat with each other. In this case, increasing the area of the heat sink fins will increase the amount of heat transfer, but the increase in area will increase the cost of materials and other limitations in the overall shape of the heat exchanger. It was.

In general, in the heat exchanger using the tube and the heat dissipation fins, the tube and the heat dissipation fins are mainly formed in a circular shape, and the heat dissipation fins are used in a shape that is vertically attached to the tube. However, in this case, the rear part of the tube is a heat transfer-vulnerable zone when the fluid flowing into the heat exchanger passes, ie, the fluid flowing into the heat exchanger passes after contact with the tube or the heat radiating fin. This is a coffin This is due to vortices and the like that occur in the downstream fluid that has passed through.

Therefore, in order to increase the efficiency of the heat exchanger and to increase the energy efficiency of the device on which the heat exchanger is mounted, a method for increasing the amount of heat transfer by minimizing the vortices generated in the downstream of the circular tube and the heat sink fin is required.

The present invention is to solve the above problems, and to increase the performance of heat transfer while effectively using the area of the heat radiation fins. Specifically, the fluid flowing into the heat exchanger is provided to the shape of the tube and the heat radiation fin to allow sufficient heat exchange in the wake while passing through the heat exchanger.

In order to solve the above object, the heat exchanger according to the present invention is provided with a tube through which the fluid flows and a plurality of heat dissipation fins formed in the tube, the heat exchanger for exchanging heat between the fluid flowing through the tube and the fluid passing through the heat dissipation fins A first bending surface formed by bending an edge of the heat dissipation fins; And a second bending surface formed by bending an edge of the heat dissipation fin at a predetermined distance from the first bending surface.

In addition, the heat dissipation fin is generally formed perpendicular to the tube as a thin plate made of metal.

In addition, the first bent surface and the second bent surface are bent in the same direction as the radiating fins, and in principle, they are formed symmetrically with respect to a line perpendicular to the central axis of the tube.

The distance between the first bent surface and the second bent surface is shortened from the upstream to the downstream in the direction in which the fluid flowing into the heat exchanger flows.

The angle formed by the first bent surface or the second bent surface with the upper surface of the heat radiation fin is made from 1 degree to 90 degrees.

In addition, the heat dissipation fin may be circular, elliptical, or may be rhombic or triangular, and may be rounded or cut in terms of fabrication.

In addition, an embodiment of the present invention, having a tube through which a fluid flows and a heat dissipation fin formed in the tube, a heat exchanger for exchanging heat between the fluid flowing through the tube and the fluid passing through the heat dissipation fin, the heat dissipation fin is elliptical The elliptical radiating fin may provide a heat exchanger in which the long axis of the ellipse is disposed perpendicular to the flow of the fluid flowing into the heat exchanger.

By the above configuration, since the bent surface provided in the heat exchanger according to the present invention serves to collect the flow of the fluid to the wake of the tube that is the heat transfer weak zone of the fluid passing through the heat exchanger heat transfer in the fin region of the downstream of the tube This is done smoothly, resulting in an advantageous effect of higher heat transfer performance.

Hereinafter, with reference to the accompanying drawings, it will be described a specific embodiment of the present invention. 1 is a perspective view of a portion of a heat exchanger according to an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a sectional view taken along the line A-A of FIG. 2.

1 to 3A, the heat exchanger 100 according to an embodiment of the present invention includes a tube 10 through which fluid flows and a plurality of heat dissipation fins 20 formed in the tube. Fluid flows inside the tube 10, and another fluid flows outside the tube and the heat dissipation fin 20, and thus heats each other due to a temperature difference between the fluid flowing inside the tube and the fluid passing outside the heat dissipation fin. Will be exchanged.

And the tube 10 is typically made of a circular cross-section cylindrical, the heat dissipation fin 20 may be attached at an angle to the tube at an angle, preferably attached to the tube perpendicularly. In addition, the heat dissipation fin is generally made of a metal material is preferably in the shape of a thin plate.

In one embodiment according to the present invention, a first bent surface 30 formed by bending a portion of the heat dissipation fin 20 is formed. As shown in FIG. 2, the first bent surface 30 is bent to form a constant angle θ with the upper surface of the heat dissipation fin, and the angle is preferably made from 1 degree to 90 degrees.

The edge of the heat dissipation fin is bent at a position spaced apart from the edge of the heat dissipation fin on which the first bent surface 30 is formed to form a second bent surface 40. In this case, the first bent surface and the second bent surface may be formed in the same direction (see FIG. 3A) in either the upper side or the lower side of the heat dissipation fin, or the first bent surface 30 and the second bent surface ( 40 are bent in opposite directions (see FIG. 3B). The first bent surface 30 and the second bent surface 40 are symmetrically formed with respect to a line perpendicular to the central axis of the tube 10. That is, as shown in Figure 2, the first bent surface and the second bent surface is symmetrical with respect to the line parallel to the flow of the (air) fluid flowing into the heat exchanger from the line perpendicular to the central axis of the tube Although based on the shape, the angle between the first bent surface and the second bent surface may have a difference within about 10 degrees. Even when the first bent surface 30 and the second bent surface 40 are bent in opposite directions (see FIG. 3B), the bent angles of the first bent surface 30 and the second bent surface 40 are mutually different. can be different.

In addition, the distance between the first bent surface and the second bent surface is formed narrower from the upstream to the downstream in the direction in which the fluid flowing into the heat exchanger flows. In other words, the first bent surface and the second bent surface which are symmetrical to each other do not maintain the same distance in the fluid flow direction, but the width between the first bent surface and the second bent surface is wide and fluid on the upstream side of the fluid flow. On the downstream side of the flow, a narrow width is formed. This is shown in Figure 2, the fluid flowing into the heat exchanger, this distance is D1 at the inlet, this distance is marked as D2 at the site of the fluid leaving the heat sink fin, where D1 is greater than D2 is established.

Therefore, as the fluid introduced into the heat radiation fins 30 passes through the heat radiation fins, the width of the flow gradually decreases from D1 to D2. And as the width of the flow passing through the heat sink fin becomes narrower, the flow rate becomes faster. When the speed of the fluid passing through the heat dissipation fin is increased, the flow of fluid to the rear part of the tube or the heat dissipation fin (the heat dissipation zone described above) occurs, so the heat transfer is performed smoothly even after the flow. As a result, the efficiency of the heat exchanger is increased.

This can be seen by looking at the flow of the fluid in FIG. Figure 4a is a flow of fluid passing through the heat exchanger in the case of not forming a bent surface on the heat dissipation fin in the heat exchanger having a circular tube and a circular heat dissipation fin, Figure 4b is a heat exchanger similar to Figure 4a as a first bent on the heat dissipation fin When the fluid is passed through the plane and the second bent surface is the appearance of fluid flow.

Looking at the figure, it can be seen that the vortex generated in the wake of the circular tube is relatively large in the case of FIG. 4A. 4B, however, the area S of the vortex is greatly reduced and thus heat transfer is promoted.

As described above, when the heat dissipation fin of the heat exchanger according to the embodiment of the present invention is used, it can be seen that the heat exchange efficiency increases because the fluid introduced into the heat exchanger is not only upstream but also smoothly exchanged in the downstream. According to the experiment, it was found that the heat transfer efficiency was increased by about 30% or more when the heat exchange was performed under the same conditions than when the first and second bent surfaces were formed on the radiating fins.

5 is an overall view of a heat exchanger according to an embodiment of the present invention. The pipe is connected to each other in a zigzag form while fluid flows therein, and a plurality of heat dissipation fins according to the present invention are disposed on the outer circumferential surface of the pipe along the pipe. The larger width between the first curved surface and the second curved surface of the heat dissipation fin is disposed toward the inlet of the fluid.

In the above, only the shape of the heat dissipation fin is a thin metal plate and a circular shape. That is, only the case where the first and second bent surfaces are formed on the circular metal plate has been described. However, the shape of the heat radiation fins is not necessarily limited thereto, and various other shapes may be possible. 6 to 9 is a plan view showing the shape of the heat exchanger heat sink fins according to another embodiment of the present invention.

6 illustrates a case in which the heat dissipation fins 60 have an elliptical shape, and the first bent surface 62 and the second bent surface 63 are formed at the edges of the elliptical shape. In this embodiment, the elliptical heat dissipation fin is preferably disposed in the tube in the direction in which the long axis of the ellipse is perpendicular to the flow of the fluid.

In FIG. 7, the outer circumferential surface of the heat dissipation fin 90 is formed of a plurality of curved lines, and the first bent surface 92 and the second bent surface 93 are formed at the edge of the heat dissipation fin 90.

8 illustrates a case in which the heat dissipation fin 70 has a rhombus shape, and the first bent surface 72 and the second bent surface 73 are formed at the edge of the rhombus.

9 illustrates a case in which the heat dissipation fin 80 has a triangular shape, and a first bent surface 82 and a second bent surface 83 are formed at edges of the triangle.

2 and 6 to 9, the edges of the heat radiation fins 70 and 80 may be rounded or cut.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a perspective view of a portion of a heat exchanger according to an embodiment of the present invention,

2 is a plan view of FIG. 1,

3A is a cross-sectional view taken along line A-A of FIG. 2, and a first bent surface and a second bent surface are formed in the same direction.

3B is a cross-sectional view taken along the line A-A of FIG. 2, wherein the first bent surface and the second bent surface are formed in different directions.

Figure 4a is a state of flow of the fluid passing through the heat exchanger when the bent surface of the heat exchanger radiating fin is not formed,

Figure 4b is a flow state of the fluid passing through the heat exchanger when the bent surface of the heat exchanger radiating fin is formed,

5 is an overall view of a heat exchanger according to an embodiment of the present invention,

6 to 9 are respectively a plan view of a heat exchanger heat sink fin according to another embodiment of the present invention.

Claims (8)

A heat exchanger having a tube through which a fluid flows inside and a plurality of heat radiating fins formed in the tube to exchange heat between a fluid flowing inside the tube and a fluid passing through the outside of the heat radiating fin, A first bent surface formed by bending an edge of the heat dissipation fins; And And a second bending surface formed by bending an edge of the heat dissipation fin at a predetermined distance from the first bending surface. The method of claim 1, The heat dissipation fin is a heat exchanger, characterized in that the metal plate is formed perpendicular to the tube. The method of claim 1, The first bent surface and the second bent surface, the heat exchanger, characterized in that formed in the same direction bent in the heat radiation fin. The method of claim 3, wherein The first bent surface and the second bent surface are symmetrical with each other based on a line perpendicular to the central axis of the tube, or the difference between the bent angles of the first bent surface and the second bent surface is within 10 degrees. Heat exchanger made. The method of claim 1, The first bent surface and the second bent surface, the heat exchanger, characterized in that formed by bending in the opposite direction from each other in the heat radiation fin. The method of claim 1, The first bent surface or the second bent surface heat exchanger, characterized in that the angle formed by the upper surface of the heat dissipation fin is 1 degree to 90 degrees. 7. The method according to any one of claims 1 to 6, The distance between the first bent surface and the second bent surface, the heat exchanger characterized in that the narrower from the upstream to downstream in the direction of the flow of fluid passing through the outside of the heat radiation fin. 7. The method according to any one of claims 1 to 6, The heat dissipation fin is a heat exchanger, characterized in that any one selected from the group consisting of circular, oval, rhombus and triangle.

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