WO2009142368A1

WO2009142368A1 - Heat exchanger

Info

Publication number: WO2009142368A1
Application number: PCT/KR2008/006462
Authority: WO
Inventors: Hyeon-Gil Shin; Jae-Myung Joo
Original assignee: Kyungdong Everon Co Ltd
Current assignee: Kyungdong Everon Co Ltd
Priority date: 2008-05-22
Filing date: 2008-11-03
Publication date: 2009-11-26
Anticipated expiration: 2010-11-22
Also published as: KR20090121706A

Abstract

The present invention relates to a heat exchanger of which a connecting portion of a tube is reinforced by inserting a tube into a burring portion formed by burring to a connecting bracket where the tube is connected in manufacturing the heat exchanger and the heat exchange efficiency is increased by connecting more tubes. A heat exchanger according to the present invention includes: a pair of head tanks through which heat exchange fluids flow into or out; a plurality of tubes that is connected by a tube connection bracket between the pair of head tanks; and radiation fins that are disposed between the plurality of tubes to exchange heat by the heat exchange fluids flowing through the plurality of tubes, in which a plurality of fixing holes 10a is formed through the tube connection bracket 10 by burring and burrs 10b for connecting the tubes 20 are formed around the edges of the fixing holes 10a, and the burrs 10b protrude to the side where the tubes 20 are connected and the tubes 20 are fitted on the outer sides of the burrs 10b.

Description

Description HEAT EXCHANGER

Technical Field

[1] The present invention relates to a heat exchanger, in detail, a heat exchanger of which a connecting portion of a tube is reinforced by inserting a tube into a burring portion formed by burring to a connecting bracket where the tube is connected in manufacturing the heat exchanger such that the heat exchange efficiency is increased by connecting more tubes. Background Art

[2] A heat exchanger is a device that allows heat to be transferred between two or more fluids separated by a wall and having different temperatures.

[3] Heat exchangers are used for a variety of fields, such as heating, air conditioning, radiator of a vehicle, power generation, waste heat recycle, chemical process, radiator for a spaceship, and manufactured in various types and shapes, depending on technical complexity and the size of heat exchangers etc.

[4] A heater that is a heat transfer medium for providing heat to an objective fluid and a coolant for taking heat are usually used in heat exchangers.

[5] Typical types of heat exchangers are a water injection type, a multi-pipe type, fin- built manifold type, and a pipe-through type etc., which use a metal pipe as a heat transfer wall. Double-pipe heat exchangers have an inner pipe and an outer pipe, in which heat is transferred between the fluid in the inner pipe and a fluid in a ring- shaped portion between the pipes. Even though this type is simple in structure, the capacity is small.

[6] Large capacity heat exchanges are manufactured in the pipe-through type that has a plurality of small pipes disposed in a large outer pipe. There are a parallel flow type in which high-temperature fluid and low-temperature fluid flow in the same direction, a counter flow type in which fluid flows in opposite directions, and a cross flow type in which fluid flows across each other.

[7] General heat exchangers include a pair of head tanks that is arranged in parallel at a predetermined distance from each other in the up-down direction, a plurality of tubes that is connected by a tube connection bracket between the pair of head tanks, and radiation fins that are disposed between the plurality of tubes to exchange heat by the fluids flowing through the plurality of tubes.

[8] In the heat exchangers having the above configuration, the plurality of tubes connected with the pair of head tanks are fixed by a connecting bracket, as shown in FIG. 1. [9] The tube connection bracket 1 has a plurality of fixing holes Ia formed by punching, ends of the tubes 3 are fitted in the plurality of fixing holes Ia, and the tubes 3 are fixed to the tube connection bracket 1 by welding the tubes 3 to the fixing holes Ia.

[10] Further, as shown in FIG. 6, fixing holes Ia are formed in a tube connection bracket

1 by burring, burrs Ib are formed at the edge of the fixing holes Ia where the tubes 3 are connected, such that the tubes 3 are fitted inside the burrs Ib and then the upper ends of the burrs 3 and the tubes 3 are welded to be fixed.

[11] In order to fix the tubes 3 in the heat exchangers of the related art, the fixing holes Ia where the tubes 3 are fitted are formed through the tube connection bracket 1 by punching, the tubes 3 are fitted in the fixing holes Ia, and the edges of the fixing holes Ia and the tubes 3 are welded to be fixed.

[12] Accordingly, the welding area of the tube 3 and the tube connection bracket 1 depends of the thickness of the tube connection bracket 1. There are problems in that when the thickness of the tube connection bracket 1 is small, the welding area is correspondingly small, such that the welded portion between the tube 3 and the tube connection bracket 1 is easily broken, whereas when the thickness of the tube connection bracket 1 is large and the fixing holes Ia are punched, as shown in FIG. 2, rugged surfaces Ic are formed around the inner circumferences of the fixing holes Ia that the fitted tubes 3 are in contact with, such that weldability is reduced.

[13] Further, when a plurality of tubes 3 are arranged densely in the tube connection bracket 1, there is a problem in that, as shown in FIG. 3, when the plurality of fixing holes Ia is formed by punching with a press mold (P) and then other fixing holes Ia are formed by moving the press mold (P) and then punching the portions between the fixing holes Ia, the punched surface of the tube connection bracket 1 which is punched is pushed, not horizontal, such that the punched surface is not plane and weldability is correspondingly reduced, when the tube 3 fitted in the fixing hole Ia is welded.

[14] Further, when fixing holes Ia are formed through a tube connection bracket 1 by burring and tubes 3 are fixed inside the burrs Ib formed at the edges of the fixing holes Ia, as shown in FIG. 6, since the tubes 3 are fitted in the burrs Ib formed around the fixing holes Ia, the outer diameter of the burr Ib is the sum of the diameter of the fixing hole Ia and two times the thickness of the tube connection bracket 1. Therefore, there is a problem in that the distance (d) between the tubes 3 fixed to the tube connection bracket 1 increases, as shown in FIG. 6, such that the number of tubes 3 that are fixed to the tube connection bracket 1 decreases and heat exchange efficiency of the heat exchanger is reduced.

[15] Further, since the outer surface of the tube 3 is fitted in the fixing hole Ia formed through the tube bracket 1 to fix the tube in the tube connection bracket 1, there is a problem in that, as shown in FIG. 5, the tube 3 should be fitted into the fixing hole Ia of the tube connection bracket 1 after a bead 3 a is formed on the tube 3 to accurately position the tube 3 when inserting the tube 3 into the fixing hole Ia. Disclosure of Invention

Technical Problem

[16] In order to overcome the above problems, it is an object of the present invention to provide a heat exchanger that can improve heat exchange efficiency by connecting more tubes to a tube connection bracket, by forming fixing holes for fixing the tubes to the tube connection bracket by burring such that burrs are formed around burred holes toward the tubes, and fitting the tubes on the outer sides of the burrs. Technical Solution

[17] In order to accomplish the object of the present invention, a heat exchanger according to the present invention includes: a pair of head tanks through which heat exchange fluid flows into or out; a plurality of tubes that is connected by a tube connection bracket between the pair of head tanks; and radiation fins that are disposed between the plurality of tubes to exchange heat by the heat exchange fluids flowing through the plurality of tubes, in which a plurality of fixing holes is formed through the tube connection bracket by burring and burrs for connecting the tubes are formed around the edges of the fixing holes, and the burrs protrude to the side where the tubes are connected and the tubes are fitted on the outer sides of the burrs .

[18] According to the heat exchanger of the present invention, when d is the distance between the tubes 20, h is the distance between the burrs 10b, and t is the thickness of the tube 20, d = hx(2xt).

Advantageous Effects

[19] According to a heat exchanger of the present invention, it is possible to fix more tubes to a predetermined-sized tube connection bracket and improve heat exchange efficiency of the heat exchanger, by fitting the tubes on the outer sides of burrs formed around the edges of a plurality of fixing holes formed at predetermined distances through the tube connection bracket by burring. Brief Description of Drawings

[20] FIGS. 1 and 2 are cross-sectional views showing a tube connection structure of a heat exchanger in the related art;

[21] FIG. 3 is a view that illustrates punching a tube connection bracket in a heat exchanger in the related art;

[22] FIGS. 4 and 5 are cross-sectional views showing another type of tube connection structure in a heat exchanger in the related art;

[23] FIG. 6 is a cross-sectional view showing another type of tube connection structure in a heat exchanger in the related art; and [24] FIG. 7 is a cross-sectional view showing a tube connection structure of a heat exchanger according to an embodiment of the present invention. Mode for the Invention

[25] The configuration and operation of a heat exchanger according to the present invention are described hereafter in detail with reference to the accompanying drawings.

[26] General heat exchangers include a pair of head tanks that is arranged in parallel at a predetermined distance from each other in the up-down direction such that heat exchange fluids flow into or out of them, a plurality of tubes that is connected by a tube connection bracket between the pair of head tanks, and radiation fins that are disposed between the plurality of tubes to exchange heat by the fluids flowing through the plurality of tubes.

[27] FIG. 7 is a cross-sectional view in which tubes have been fixed to a tube connection bracket in a heat exchanger according to an embodiment of the present invention.

[28] As shown in the figure, a heat exchanger according to the present invention has a structure in which a plurality of fixing holes 10a is formed through a tube connection bracket 10 for mounting tubes 20 to head tanks by burring and burrs 10b are formed around the fixing holes 10a by burring, protruding toward the side where the tubes 20 are connected, and the tubes 20 are fitted on the outer sides of the burrs 10b.

[29] When the burrs 10b are formed around the edges of the plurality of fixing holes 10a through the tube connection brackets 10, the plurality of burrs 10b are formed at predetermined distances, in which since the tubes 20 are fitted on the outer sides of the burrs 10b, it is preferable that the fixing holes 10a with the burrs 10b are formed smaller than the inner diameter of the tubes 20.

[30] On the other hand, when the fixing holes 10a are formed through the tube connection bracket 20 by punching, the flatness of the tube connection bracket 10 where the tubes 20 are connected is not maintained due to repeated punching, such that weldability between the tube connection bracket 10 and the tubes 20 is reduced. Accordingly, the plurality of fixing holes 10a are formed by punching once in burring, in which the burring is performed such that the gaps between the fixing holes 10a at which the tube connection bracket 10 do not deform by punching in forming the fixing holes 10a, that is, the gaps (h) between the burrs 10b formed around the fixing holes 10a are maintained constantly.

[31] That is, as the fixing holes 10a for fixing the tubes 20 to the tube connection bracket

10 are formed at predetermined distances, the burrs 10 formed around the fixing holes 10a are also formed with the constant gaps (h) maintained. When d is the gap between the outer side of the burr 10b and the tube 20, t is the thickness of the tube 20, and T is the thickness of the burr 10, the distance (d) between the tubes 20 can be expressed by d = h x (2xt).

[32] On the contrary, in the related art, as shown in FIG. 6, a tube is fixed on the inner side of a burr formed around a fixing hole, the distance between the tubes fixed in the burrs of a plurality of fixing holes formed through a tube connection bracket can be expressed by d = h + (2xT).

[33] That is, it can be seen, in the heat exchanger according to the present invention, that the tubes 20 fixed to the tube connection bracket 10 are disposed closer than the related art as much as the distance (2xt)+ (2xT).

[34] Accordingly, it is possible to fix a higher number of tubes 20 than fixing tubes to a tube connection bracket of the related art on the assumption that a plurality of tubes 20 are fixed to a tube connection bracket 10 having the same size, such that heat exchange efficiency of the heat exchanger can be increased.

[35] It should not be construed that the embodiment of the present invention described above limits the spirit of the present invention. The scope of protection of the present invention is limited only by the claimed invention and the present invention may be modified in various ways on the basis of the spirit of the present invention by those skilled in the art. Therefore, changes and modifications are apparent to those skilled in the art and will pertain to the scope of protection of the present invention. Industrial Applicability

[36] As described above, by applying the present invention to heat exchangers of boilers, it is possible to increase heat exchange efficiency by connecting more tubes while firmly fixing the tubes for heat exchange.

[37]

Claims

[ 1 ] A heat exchanger comprising : a pair of head tanks through which heat exchange fluid flows into or out; a plurality of tubes that is connected by a tube connection bracket between the pair of head tanks, and radiation fins that are disposed between the plurality of tubes to exchange heat by the heat exchange fluids flowing through the plurality of tubes, wherein a plurality of fixing holes 10a is formed through the tube connection bracket 10 by burring and burrs 10b for connecting the tubes 20 are formed around the edges of the fixing holes 10a, and the burrs 10b protrude to the side where the tubes 20 are connected and the tubes

20 are fitted on the outer sides of the burrs 10b. [2] The heat exchanger according to claim 1, wherein when d is the distance between the tubes 20, h is the distance between the burrs 10b, and t is the thickness of the tube 20, d = h x (2xt).