KR20030027609A - Heat exchanger - Google Patents

Abstract

PURPOSE: A heat exchanger is provided to cut off flow of heat in the heat exchanger and to improve pressure-proof quality. CONSTITUTION: A heat exchanger includes a first header pipe(10) and a second header pipe(20) placed parallel to each other and having at least two compartments(12,14,22,24) separated from each other and linearly arranged, respectively; a plurality of radiating tubes(50) connecting the compartments of the first header pipe and the second header pipe facing each other to form at least two slabs together with the connected compartments; a refrigerant inlet pipe(30) formed on the compartment placed on one end of the first header pipe; return holes formed on the first header pipe and the second header pipe following flow of refrigerant to connect the neighboring compartments; and a refrigerant outlet pipe(40) formed on the compartment forming the last slab in flow of refrigerant for refrigerant to flow out.

Description

Heat exchanger

The present invention relates to a heat exchanger, and more particularly to a heat exchanger using a fluid having a supercritical pressure refrigeration cycle, such as carbon dioxide as a refrigerant.

In general, a heat exchanger is a device in which a high temperature fluid and a low temperature fluid transfer heat from a high temperature to a low temperature through a heat exchanger wall to perform heat exchange. Although HFC refrigerants have been mainly used as an operating medium of air conditioner systems having such heat exchangers, such HFC refrigerants are recognized as one of the main factors of global warming, and regulations on their use are gradually being expanded. Under these circumstances, research on carbon dioxide refrigerants as a next generation refrigerant to replace HFC refrigerants has been actively conducted.

Carbon dioxide, the representative of such next-generation refrigerants, corresponds to about one-third of R134a, a global warming index (GWP), is a representative HFC refrigerant. In addition, it has the following advantages as a refrigerant. In other words, the compression ratio is excellent due to the low operating compression ratio, and the heat transfer performance is very good so that the temperature difference between the inlet temperature of the secondary fluid air and the outlet temperature of the refrigerant can be much smaller than that of the conventional refrigerant. This advantage can be used to extract heat at low outside temperatures in winter, so it can be applied to heat pumps that perform cooling in summer and heat in winter.

In addition, since the carbon dioxide has a volume cooling capacity (evaporative latent heat x gas density) of 7 to 8 times that of the conventional refrigerant R134a, the capacity of the compressor can be greatly reduced, and the surface tension is small, so the boiling heat transfer is excellent, and the constant pressure specific heat This large and low viscosity has excellent heat transfer performance and therefore has excellent thermodynamic properties as a refrigerant. In addition, in terms of the refrigeration cycle, the gas-cooling pressure is 6 to 8 times higher (about 90 to 130 bar) than the conventional one, and the loss due to the pressure drop of the refrigerant inside the heat exchanger is higher than that of the conventional refrigerant. The relatively small pressure drop allows the use of microchannel heat exchanger tubes which are known to have a large but excellent heat transfer performance.

The heat exchanger using carbon dioxide as a refrigerant can be classified into two types, namely, a multi-pass method and a multi-slab method.

The multi-pass method increases the number of passes of the refrigerant flowing through the tube through a plurality of baffles in the header pipe. The distribution of the refrigerant in the heat exchanger is good, but carbon dioxide, which is a refrigerant when the refrigerant is cooled, is in the heat exchanger. Since there is no condensation process in the system, the temperature is continuously lowered, and thus, a temperature deviation in the entire heat exchanger is increased, causing a problem that heat flows itself along the surface of the heat exchanger through the tube and the fin. This heat flow prevents the refrigerant from exchanging heat with the external inlet air and naturally reduces the heat exchange performance.

In the multi slab method, a plurality of rows of tubes are arranged so that the refrigerant exchanges heat as the tube passes through the heat of the tubes, which can block heat flow as in the multi-pass method, and thus the refrigerant operates at a high pressure such as carbon dioxide. In the heat exchanger using the is known as a better structure. However, such a multi-slab heat exchanger must attach a pipe to communicate each slab, but it has a structure vulnerable to high pressure. In addition, the distribution of the refrigerant in the heat exchanger may be slightly lower than the multi-pass method.

The present invention is to overcome the limitation of the heat exchanger using a refrigerant that operates under a high pressure, such as carbon dioxide as a heat exchange medium, the fluid that can cause the self heat flow by continuously lowering the temperature in the heat exchanger, such as carbon dioxide refrigerant In the heat exchanger to be used as an object, it is an object to provide a heat exchanger excellent in pressure resistance characteristics while blocking the heat flow in the heat exchanger itself.

Another object of the present invention is to enable a uniform distribution of the refrigerant in the heat exchanger.

1 and 2 are perspective views of a heat exchanger according to an embodiment of the present invention without a baffle.

3A and 3B are perspective views of a heat exchanger according to an embodiment of the present invention employing a baffle.

4a and 4b are perspective views of a heat dissipation tube of a heat exchanger according to the present invention;

5 is a partial perspective view showing a first header pipe of a heat exchanger according to an embodiment of the present invention.

6A, 6B and 6C are exploded perspective views illustrating embodiments of a second header pipe of a heat exchanger according to an embodiment of the present invention.

Figure 7a is an operating state diagram showing the refrigerant flow of the heat exchanger according to an embodiment of the present invention according to FIG.

Figure 7b is an operating state diagram showing the refrigerant flow of the heat exchanger according to an embodiment of the present invention according to Figure 3a.

Figure 7c is an operating state diagram showing the refrigerant flow of the heat exchanger according to an embodiment of the present invention according to Figure 3b.

※ Explanation of code for main part of drawing

10: first header pipe 12, 14: first and second compartment

20: second header pipe 22, 24: 3rd and 4th compartment

11, 21: Cap 29: Return hole

16, 26: baffle 30: refrigerant inlet pipe

40: refrigerant outlet tube 50: heat dissipation tube

50a, 50b: first and second tube rows 52: microtubes

60: heat sink fin

In order to achieve the above object, the present invention is arranged in parallel with a predetermined interval spaced apart from each other, each of the first and second header pipes having at least two or more compartments arranged independently and in a row, the refrigerant flows therein, A plurality of heat dissipation tubes forming at least two slabs together with the compartments of the first and second header pipes communicating with the facing compartments of the first and second header pipes, and at one end of the first header pipe; A refrigerant inlet tube formed in the located compartment and a return formed in the first and second header pipes to communicate adjacent compartments with each other in accordance with the flow of the refrigerant so that the refrigerant introduced from the refrigerant inlet tube flows in the slab unit; A coolant outlet pipe formed in a hole constituting a final slab of the slab according to the flow of the hole and the coolant to allow the coolant to flow out; It provides a heat exchanger comprising a.

In order to achieve the above object, the present invention is a first header pipe having a first and second compartments independent of each other, and the first header pipe and the first header pipe are spaced apart in a predetermined interval in parallel, the first and second compartments A second header pipe having at least third and fourth compartments opposed to each other, the second header pipe having a return hole for communicating the third and fourth compartments with each other, the first compartment and the third compartment communicating with each other; A plurality of heat dissipation tubes formed to communicate refrigerant between the second compartment and the fourth compartment, a refrigerant inlet tube formed in the first compartment, into which the refrigerant is introduced, and a refrigerant discharged from the second compartment; It provides a heat exchanger comprising a refrigerant outlet pipe.

In such heat exchangers, air causing heat exchange with the refrigerant may be arranged to flow in from the direction in which the refrigerant outlet pipe is formed.

In order to achieve the above object, the present invention also provides a first header pipe having first and second compartments that are independent of each other, parallel to the first header pipe, and spaced apart from the first header pipe by a predetermined distance. A second header pipe having at least third and fourth compartments facing each other, the second header pipe having a return hole communicating the third and fourth compartments with each other, the first compartment and the third compartment communicating with each other; A plurality of heat dissipation tubes formed to communicate refrigerant between the second compartment and the fourth compartment, a refrigerant inlet tube formed in the first header pipe to introduce the refrigerant, and formed in the first header pipe; It is also provided in the refrigerant outlet pipe and the first and second header pipe that the refrigerant flows out may close at least two or more of the compartments to establish a multi-stage path to the flow of the refrigerant It provides a heat exchanger, characterized in that formed, including a plurality of baffles formed.

According to another feature of the invention, the baffle formed in the second header pipe is a shape that closes the third compartment and the fourth compartment at the same time, the baffle formed in the first header pipe is the first compartment or the second compartment. It can be made to be a shape to close independently.

At this time, the flow of the refrigerant returned through the return hole by the baffle formed in the second header pipe may be an even number along the longitudinal direction of the second header pipe, the refrigerant inlet pipe and the refrigerant outlet pipe All may be formed in the first compartment.

In addition, the flow of the refrigerant returned through the return hole by the baffle formed in the second header pipe may allow an odd number to be formed along the length direction of the second header pipe, wherein the refrigerant inlet pipe and the refrigerant outlet pipe are May be formed in the first compartment and the second compartment, respectively.

According to another feature of the invention, the return hole may be made of at least two or more holes arranged at equal intervals along the second header pipe, or as a single hole formed along the longitudinal direction of the second header pipe Can be done.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention. As can be seen in the accompanying drawings, the heat exchanger according to the present invention is implemented as a single header and tank without a separate tube heat exchanger of the multi-slab type as described above.

1 is a perspective view of a heat exchanger according to a preferred embodiment of the present invention, as can be seen in the figure, the heat exchanger of the present invention, the first and second compartments 12, 14 and the third and fourth compartments 22 Each of the header pipes 10 and 20 has a first header pipe 10 and a second header pipe 20 each having an upper and lower sides 24, and the upper and lower portions of the header pipes 10 and 20 are sealed with caps 11 and 21. In addition, a plurality of heat dissipation tubes 50 are disposed between the first header pipe 10 and the second header pipe 20 so that the refrigerant flows, and the heat dissipation fins 60 are disposed between the heat dissipation tubes 50. It is installed to allow the refrigerant flowing in the tube 50 to facilitate heat exchange with the air that is the second heat exchange medium. In addition, a coolant inlet pipe 30 is installed in the first compartment 12 of the first header pipe 10, and a coolant outlet pipe 40 is installed below the second compartment 14. The third compartment 22 and the fourth compartment 24 of the second header pipe 20 are in communication with each other as described below.

In the heat exchanger configured as described above, the compartments and the heat dissipation tubes form a slab, the first tube row 50a communicating with the first compartment 12 and the third compartment 22 and the first and third compartments. (12) (22) forms a slab, the second tube row 50b communicating with the second compartment 14 and the fourth compartment 24 and these second and fourth compartments 14,24 This forms another slab. Therefore, the refrigerant introduced through the refrigerant inlet pipe 30 attached to the first compartment 12 is heat-exchanged through the slab composed of the first and third compartments 12 and 22 and the first tube row 50a. After being returned from the second header pipe 20 and undergoing heat exchange again through a slab composed of the second and fourth compartments 14 and 24 and the second tube row 50b, the second compartment 14 is provided in the second compartment 14. The refrigerant flows through the outlet pipe 40. At this time, as can be seen in Figure 1, such a heat exchanger is such that it is possible to increase the overall heat exchange efficiency by allowing air to flow from the side where the outlet pipe 40 of the refrigerant is installed, so that the heat exchanger refrigerant outlet pipe 40 is It is preferable to arrange the air in the direction in which it enters.

Figure 2 shows a heat exchanger according to another embodiment of the present invention having one more slab as described above, wherein the first header pipe 10 and the second header pipe 20 are fifth and sixth compartments 15, respectively. ) 25, the tube 50 may also be formed in the compartments 15 and 25. The fifth and sixth compartments 15 and 25 and the third tube row 50c communicating with each other form another slab. Thus, the refrigerant is returned after the first slab 12, 22, 50a, and then again through the second slab 14, 24, 50b, and then the third slab 15, 25. It flows out through 50c. At this time, the coolant outlet pipe 40 is installed in the sixth compartment 25. In addition to the communication between the third and fourth compartments 22 and 24 of the second header pipe 20, the second compartment 14 and the fifth compartment 15 of the first header pipe 10 communicate with each other. It is done. In this case, as in the above-described embodiment, the heat exchanger is disposed so that the slab to which the refrigerant outlet pipe 40 is attached faces in the direction in which air is introduced.

Such a configuration may be applied to the heat exchanger constituting a plurality of slabs further provided with a compartment, of course.

Meanwhile, the structures of the tube 50 and the first and second header pipes 10 and 20 that may be employed in the heat exchanger as described above are described below. The structure of the tube 50 and the first and second header pipes 10 and 20 to be described below can be applied to all embodiments of the present invention.

First, as can be seen in FIG. 1, the tube rows 50a and 50b communicating with the independent compartments are separated from each other. As shown in FIG. 4A, the tubes forming the first tube row 50a are separated. It can be separated without any connection member between the tube forming the second tube row 50b, as can be seen in Figure 4b, the tube and the second tube row (50b) forming the first tube row (50a) Bridge is formed between the tubes forming a) can be formed integrally at the manufacturing stage. In addition, the inside of each of the tubes 50 may be formed of a plurality of microtubes 52, so that the heat exchange efficiency of the refrigerant flowing therein, particularly the carbon dioxide refrigerant, may be good.

FIG. 5 is a partial perspective view illustrating the first header pipe 10 in more detail in FIG. 1. As shown in the figure, the first header pipe 10 in the preferred embodiment of the present invention includes independent first compartments 12 and second compartments 14, so that they do not communicate with each other.

The first header pipe 10 is composed of a first tank portion 18 and the first header portion 17, it can be combined by a method such as a brazing process. In the heat exchanger which uses carbon dioxide especially as a refrigerant | coolant, since a header pipe needs to be able to endure at high pressure, in the present invention, the header part is manufactured by pressing, and the tank part is produced by extrusion and joined by brazing. In this case, in order to improve the brazing property, at least one side of the tank and the header may be formed by caulking to form a caulking unit, and then brazing may be performed. 1, a plurality of fastening grooves 13 are formed in the compartments 12 and 14 so that the tube rows 50a and 50b may be coupled to the header 17.

6A, 6B and 6C are exploded perspective views showing embodiments of the second header pipe 20 of the heat exchanger of the present invention shown in FIG.

As can be seen in the figure, the second header pipe 20 according to the invention comprises a third compartment 22 and a fourth compartment 24, which are in communication with one another via a return hole 29. The second header pipe 20 also includes a second header portion 27 having a plurality of fastening grooves 23 formed therein and return holes 29 formed in a longitudinal direction so as to couple tube rows to each compartment. The two tanks 28 can be manufactured by the method of press and extrusion, respectively, and joined by brazing. Of course, at this time, as in the first header pipe, a caulking portion may be formed on at least one side of the header and the tank, and then caulking may be performed. The return connecting the third compartment 22 and the fourth compartment 24 may be performed. The shape of the hole 29 may be formed along the longitudinal direction of the return holes 29 in the shape of a plurality of rectangular grooves, as shown in Figure 6a, as shown in Figure 6b, as a single groove It may be formed. And, as can be seen in Figure 6c, in order to maintain a more solid bond to the high-pressure refrigerant, it may be formed in a hole shape.

The shape and structure of the first header pipe 10 and the second header pipe 20 as described above may be variously modified within the scope of the technical idea of the present invention.

First, the first header pipe 10 and the second header pipe 20 as described above may be applied as it is in the embodiment shown in FIGS. 1 and 3A and 3B described later. In addition, in this embodiment, since the first compartment 12 and the second compartment 14 of the first header pipe 10 are not mutually communicated with each other, they are separated into two pieces of header and pipe. It can be produced in one piece without bonding.

In addition, although not shown separately in the embodiment as shown in FIG. 2, as can be seen in FIG. 2, the first header pipe 10 includes first, second and fifth compartments 12, 14, and 14 ′, Since the second compartment 14 and the fifth compartment 14 ′ communicate with each other, the coupling structure of the second compartment 14 and the fifth compartment 14 ′ has a return hole as described with reference to FIGS. 6A to 6C. Should be provided. Also in the second header pipe 20, the third compartment 22 and the fourth compartment 24 are communicated by the return holes as shown in Figs. 6A to 6C, but the fourth compartment 24 and the sixth compartment are communicated with each other. Compartment 24 'should not be in communication with each other, so it should exhibit a structure as shown in FIG.

Next, another embodiment of the present invention for increasing the distribution of the refrigerant that may be somewhat weak in such a multi-slab type heat exchanger will be described.

3a and 3b is to add a baffle in the heat exchanger consisting of a two-stage slab as shown in FIG. 1 to give multiple passes to the flow of the refrigerant. The structure of the heat exchanger to be described below is different from the configuration of the baffle and the coolant outlet pipe 40 and the configuration of FIG.

First, the heat exchanger according to the preferred embodiment of the present invention, which can be seen in FIG. 3A, has a baffle 16, 26 in the first and second header pipes 10, 20, respectively. It is installed. The first header pipe 10 is provided with a single baffle 16 for closing only the first compartment 12, and the second header pipe 20 simultaneously closes the third and fourth compartments 22 and 24. The paired baffle 26 is formed below the formation position of the single baffle 16. Here, the single baffle 16 refers to being formed only in one of two compartments provided in the header pipe, and the paired baffle 26 refers to simultaneously closing both compartments provided in the header pipe. Thus, the baffle 26 formed in the second header pipe 20 may have two passes of the refrigerant returning the second header pipe 20, and the pair of baffles 26 may be connected to the second header pipe 20. If three are installed, the return path of the refrigerant is four. In other words, when an odd number of pairs of baffles 26 are provided in the second header pipe 20, an even number of return paths of the coolant is generated, and in the heat exchanger having such a configuration, as shown in FIG. 3A, the coolant outlet pipe 40 is It is installed in the same compartment as the refrigerant inlet pipe (30).

In the heat exchanger having such a structure, the first header pipe 10 has a structure in which the first compartment 12 and the second compartment 14 are separated from each other, as shown in FIG. 5. (18) may be manufactured by a brazing process, and it may be manufactured integrally. In addition, the structure of the second header pipe 20 includes a return hole so that the third compartment 22 and the fourth compartment 24 communicate with each other as shown in FIGS. 6A to 6C.

Next, the heat exchanger shown in FIG. 3B forms two pairs of baffles 26 and 26 ′ in the second header pipe 20 so that three return passes of the refrigerant appear. At this time, the first header pipe 10 is formed with a single baffle 16, 16 'in the first compartment 12 and the second compartment 14, respectively. The coolant outlet pipe 40 is installed in the second compartment 14 which is a different compartment from the compartment 12 in which the coolant inlet pipe 30 is installed. When an odd number of return passes of the coolant appear in the second header pipe, the coolant inlet pipe 30 and the coolant outlet pipe 40 are attached to different compartments. However, in the embodiments shown in FIGS. 3A and 3B, the refrigerant inlet pipe 30 and the refrigerant outlet pipe 40 are both formed in the first header pipe 10 regardless of the number of return passes of the refrigerant.

Next, the operation of the present invention having the above configuration will be described.

7A, 7B, and 7C are diagrams illustrating the flow of a refrigerant flowing therein according to different embodiments of the present invention shown in FIGS. 1, 3A, and 3B, respectively.

First, in the heat exchanger as shown in FIG. 7A, the refrigerant introduced through the refrigerant inlet pipe 30 formed in the first compartment 12 is filled into the entire first compartment 12, and the refrigerant is filled in the first tube row ( It flows through the 50a) to the third compartment 22 of the second header pipe 20. The refrigerant introduced into the third compartment 22 is returned to the fourth compartment through a return hole that communicates the third compartment 22 and the fourth compartment 24 with the second tube row 50b. Flows into the compartment 14. The refrigerant introduced into the second compartment 14 flows out through the refrigerant outlet pipe 40. At this time, the air to be heat-exchanged with the refrigerant is introduced from the second tube row (50b) side and first heat exchange with the refrigerant flowing through the second tube row (50b), the air and the first tube row (the temperature is raised to some extent) As the 50a) undergoes heat exchange, the temperature difference between the first tube row 50a and the second tube row 50b is not large so that the refrigerant is separated between the first tube row 50a and the second tube row 50b. It can be prevented from causing heat exchange. Therefore, the heat exchange efficiency of the heat exchanger can be increased as a whole.

In the heat exchanger as shown in FIG. 7B, the refrigerant introduced through the refrigerant inlet pipe 30 coupled to the first compartment 12 of the first header pipe 10 is formed in the first compartment 12. The lower flow is blocked by the single baffle 16, which flows through the first tube row 50a to the third compartment 22 of the second header pipe 20. This refrigerant is returned from the second header pipe 20 to the fourth compartment 24 through a return hole that communicates the third and fourth compartments 22 and 24 with each other, and at the same time, the second header pipe 20 The lower flow is blocked by the pair of baffles 26 formed together in the 3 and 4 compartments 22 and 24 and flows into the second tube row 50b so as to flow the second compartment 14 of the first header pipe 10. Will flow). Since the baffle is not formed in the second compartment 14, the refrigerant flowing in along the second tube row 50b flows to the lowermost portion, where it flows back to the fourth compartment 24 of the second header pipe 20. It flows through the 2nd tube row 50b. The refrigerant introduced into the lower side of the fourth compartment 24 is returned to the third compartment 22 again through the return hole, and flows into the first compartment 12 via the first tube row 50a and the first compartment 12. Out of the heat exchanger through the refrigerant outlet pipe 40 coupled to (12).

Next, in the heat exchanger as shown in FIG. 7C, single baffles 16 and 16 ′ are formed in the first compartment 12 and the second compartment 14 of the first header pipe 10, respectively. Two pairs of baffles 26 and 26 'are formed in the second header pipe 20. In the heat exchanger having such a structure, the refrigerant introduced through the refrigerant inlet pipe 30 coupled to the first compartment 12 flows downward by a single baffle 16 formed in the first compartment 12. It is blocked through the first tube row 50a flows to the third compartment 22 of the second header pipe 20. In the second header pipe 20, the refrigerant is returned to the fourth compartment 24 through the return hole and simultaneously formed in the third and fourth compartments 22 and 24 of the second header pipe 20. The lower portion is blocked by the second pair of baffles 26 and flows to the second tube row 50b to the second compartment 14 of the first header pipe 10. The refrigerant is again blocked by a single baffle 16 'formed in the second compartment 14 and flows back through the second tube row 50b to the fourth compartment 24, where the second The lower flow is blocked by the pair of baffles 26 ′ and flows into the third compartment 22. The refrigerant flowing into the first compartment 12 from the third compartment 22 via the first tube row 50a flows to the lowermost portion of the first compartment 12, and then again the second header pipe 20 is formed. The three compartments 22 flow through the first tube row 50a. The refrigerant introduced into the third compartment 22 is returned to the fourth compartment 24 through the return hole, flows into the second compartment 14 through the second tube row 50b, and enters the second compartment 14. Out of the heat exchanger through the coupled refrigerant outlet pipe 40.

In these heat exchangers as shown in Figs. 7B and 7C, it is possible to smoothly distribute the refrigerant throughout the heat exchanger, and also adopt the multi-slap method as shown in Fig. 7A, so that the heat exchange efficiency can be excellent.

According to the present invention as described above, as the carbon dioxide refrigerant heat exchanges with each other while flowing through the tube of the heat exchanger, it is possible to prevent the heat exchange efficiency with the outside air is lowered.

In addition, even a refrigerant operating at a high pressure such as carbon dioxide can exhibit excellent pressure resistance characteristics, it is possible to evenly distribute the amount of refrigerant throughout the header pipe.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it will be understood that various modifications and other embodiments are possible to those skilled in the art. Therefore, the protection scope of the present invention will be defined by the appended claims.

Claims (13)

First and second header pipes spaced apart from each other at a predetermined distance and arranged in parallel, each having at least two or more compartments arranged independently and in a row; A plurality of heat dissipation tubes in which a refrigerant flows and forms at least two slabs together with the compartments of the first and second header pipes communicating with the compartments facing the first and second header pipes; A refrigerant inlet pipe formed in a compartment located at one end of the first header pipe; A return hole formed in the first and second header pipes to communicate adjacent compartments with each other so that the coolant introduced from the coolant inlet pipe flows through the slab in units; And And a coolant outlet pipe formed in a compartment of the slab forming a final slab according to the flow of the coolant to allow the coolant to flow out. A first header pipe having first and second compartments independent of each other; A return hole disposed parallel to the first header pipe and spaced apart from the first header pipe and having at least third and fourth compartments facing the first and second compartments, and communicating the third and fourth compartments with each other; A second header pipe provided; A plurality of heat dissipation tubes communicating with the first compartment and the third compartment and communicating with the second compartment and the fourth compartment to allow a refrigerant to flow therein; A refrigerant inlet pipe formed in the first compartment and into which the refrigerant is introduced; And The heat exchanger is formed in the second compartment and comprises a refrigerant outlet pipe for the refrigerant flows out. The method according to claim 1 or 2, And the heat exchanger is arranged such that air causing heat exchange with the refrigerant flows from a direction in which the refrigerant outlet pipe is formed. The method according to claim 1 or 2, The return hole is a heat exchanger comprising at least two holes arranged at equal intervals along the longitudinal direction of the second header pipe The method according to claim 1 or 2, And the return hole comprises a single hole formed along a length of the second header pipe. A first header pipe having first and second compartments independent of each other; A return hole disposed parallel to the first header pipe and spaced apart from the first header pipe and having at least third and fourth compartments facing the first and second compartments, and communicating the third and fourth compartments with each other; A second header pipe provided; A plurality of heat dissipation tubes communicating with the first compartment and the third compartment and communicating with the second compartment and the fourth compartment to allow a refrigerant to flow therein; A refrigerant inlet pipe formed in the first header pipe to introduce the refrigerant; A coolant outlet pipe formed in the first header pipe to allow the coolant to flow out; And a plurality of baffles installed on the first and second header pipes to close at least two or more compartments of the compartments so as to set a multi-stage path to the flow of the refrigerant. The method of claim 6, The baffle formed in the second header pipe is a shape for closing the third compartment and the fourth compartment at the same time, the baffle formed in the first header pipe is a shape for closing the first compartment or the second compartment alone. Heat exchanger The method of claim 7, wherein Heat exchanger, characterized in that the even flow of the refrigerant returned through the return hole by the baffle formed in the second header pipe is formed along the longitudinal direction of the second header pipe. The method of claim 8, And the refrigerant inlet tube and the refrigerant outlet tube are both formed in the first compartment. The method of claim 7, wherein The flow of the refrigerant returned through the return hole by the baffle formed in the second header pipe is such that the odd number is formed along the longitudinal direction of the second header pipe. The method of claim 10, And the coolant inlet pipe and the coolant outlet pipe are formed in the first compartment and the second compartment, respectively. The method according to any one of claims 6 to 11, And the return hole comprises at least two holes disposed at equal intervals along the second header pipe. The method according to any one of claims 6 to 11, And the return hole comprises a single hole formed along a length of the second header pipe.