KR20040105439A - Heat exchanger for using CO2 as a refrigerant - Google Patents

Abstract

PURPOSE: A heat exchanger for carbon dioxide is provided to reduce a brazing bond part by reducing the number of passages of a refrigerant, thereby preventing leakage of a high-pressure refrigerant. CONSTITUTION: First and second header pipes(310,320) are formed by combining header parts and tank parts, having independent compartments(311,321) inducing a flow of a refrigerant along by length direction. A heat dissipating tube(350) is communicated with the compartments of the header pipes for forming a heat exchange part. A refrigerant inlet pipe(370) is placed at one end of the first header pipe for moving the refrigerant in. A refrigerant outlet pipe(380) is placed at one end of the second header pipe for discharging the refrigerant. The heat dissipating tube has unit heat dissipating tubes(351,352,353) arranged in direction orthogonal to direction that outside air flows, and two or more return parts(354,355) are formed at a part where the unit heat dissipating tubes are connected with each other, thereby having a single flow path.

Description

Heat exchanger for using CO2 as a refrigerant

The present invention relates to a heat exchanger, and more particularly to a heat exchanger using carbon dioxide as a refrigerant.

Typically, a heat exchanger is a device in which a high temperature refrigerant and a low temperature refrigerant transfer heat from a high temperature to a low temperature through a heat exchanger wall surface to perform heat exchange. HFC refrigerants have been mainly used as a working medium for air conditioner systems having such heat exchangers. However, HFC refrigerants have been recognized as one of the main factors of global warming, and regulations on their use are gradually being expanded. Under these circumstances, researches on carbon dioxide (CO ₂ ) refrigerant as a next generation refrigerant to replace the HFC refrigerant is being actively conducted.

Carbon dioxide, the representative of such next-generation refrigerants, corresponds to about 1/1300 of R134a, which is a representative HFC refrigerant with a global warming index (GWP). In addition, it has the following advantages as a refrigerant. First, the compression ratio is low, the compression efficiency is excellent, and second, the heat transfer performance is very good, the temperature difference between the inlet temperature of the secondary fluid air and the outlet temperature of the refrigerant can be much smaller than the conventional refrigerant. This advantage can be used to extract heat at low outside temperatures in winter, so it is also applicable to heat pumps that perform cooling in summer and heat in winter.

In addition, since the volumetric capacity (evaporative latent heat x gas density) is 7 to 8 times that of the conventional refrigerant R134a, the capacity of the carbon dioxide can be greatly reduced, and the surface tension is small, so the boiling heat transfer is excellent, and the static pressure It has excellent thermodynamic properties as a refrigerant because of its high specific heat and low liquid viscosity. In addition, when viewed from the side of the refrigeration cycle, the gas-cooling pressure is 6 to 8 times (about 90 to 130 bar) higher than the conventional, the loss due to the pressure increase of the refrigerant in the heat exchanger compared to 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.

FIG. 1 illustrates a conventional heat exchanger 100 for carbon dioxide, and FIG. 2 separately illustrates the second header pipe 120 of FIG. 1.

1 and 2, the heat exchanger 100 includes a first header pipe 110 and a second header pipe 120, and the first and second header pipes 110 and 120. Upper and lower portions of the upper and lower end caps 130 and 140 are sealed. A plurality of heat dissipation tubes 150 are disposed between the first and second header pipes 110 and 120 at predetermined intervals, and heat dissipation fins 160 are disposed between the heat dissipation tubes 150. .

First and second compartments 111 and 112 are formed in the first header pipe 110, and third and fourth compartments 121 and 122 are formed in the second header pipe 120. Formed. The coolant inlet pipe 170 is installed in the first compartment 111, and the coolant discharge pipe 180 is installed in the second compartment 112.

In addition, the second header pipe 120 includes a second header portion 124 and a second tank portion 125 coupled to the second header portion 124 to partition the third and fourth compartments 121 and 122. Like the second header pipe 120, the first header pipe 110 includes a first header part and a first tank part, and a detailed description thereof will be omitted.

The third and fourth compartments 121 and 122 formed in the second header pipe 120 are in communication with each other. The third and fourth compartments 121 and 122 are communicable by a return hole 123 formed in the portion 126 that is coupled to each other.

The heat exchanger 100 for carbon dioxide configured as described above forms compartments and heat dissipation tubes with slab. That is, the first compartment 111 and the third compartment 121 communicate with each other by the first heat dissipation tube 151 to form one slab, and the second compartment 112 and the fourth compartment 122 are made of the first compartment. It communicates with the 2 heat radiating tubes 122, and forms another slab.

In the heat exchanger 100 for carbon dioxide having the above configuration, the refrigerant introduced through the refrigerant inlet pipe 170 installed in the first compartment 111 may be the first and third compartments 111 and 121 and the first heat dissipation. Heat exchange occurs through the slab formed of the tube 151, and is returned through the return hole 123 of the second header pipe 120 to the second and fourth compartments 112, 122 and the second heat dissipation tube. After heat exchange is performed through the slab 152, the refrigerant is discharged through the refrigerant discharge pipe 180 installed in the second compartment 112.

However, the conventional heat exchanger 100 for carbon dioxide has the following problems.

First and second header pipes 110 and 120 are installed at both ends of the heat dissipation tube 150, and the header pipes 110 and 120 are first to fourth compartments that are flow paths of the refrigerant. Each header portion and tank portion are brazed to partition 111 to 122).

In addition, the first and second heat dissipation tubes 151 and 152 are coupled to the first and fourth compartments 111 to 122 in the first and second header pipes 110 and 120 to form respective slabs. Both ends of are inserted and brazed.

As such, in the heat exchanger 100 using a refrigerant operating at a high pressure such as carbon dioxide, having many joints such as brazing bonds may cause a fatal problem in structural stability. Accordingly, the high-pressure working refrigerant during driving is likely to leak.

In addition, since both ends of the heat dissipation tube 150 are connected to the respective compartments 111 to 122 to form respective slabs, the number of flow paths through which the refrigerant flows increases. This increase in the number of flow paths is associated with the number of compartments and becomes a factor of increasing the total weight of the heat exchanger 100.

In addition, when high-pressure carbon dioxide is used as the refrigerant, a separation wall 126 is formed to partition the first and second compartments 121 and 122 to separate the flow path of the refrigerant, and the thickness of the separation wall 126 is provided. Due to the distance between the heat dissipation tube 150 is far.

In addition, the heat dissipation tube 150 is maintained in the first and second compartments 121 and 122 in a direction perpendicular to the direction in which the refrigerant flows, thus preventing the flow of the refrigerant.

In particular, in order for the heat dissipation tube 150 to be inserted into the compartments 121 and 122 in a horizontal state without an angle, the flow path width of the refrigerant must be at least larger than the width of the heat dissipation tube 150. As a result, the overall size of the heat exchanger 100 is increased.

The present invention is to solve the above problems, to form a return by bending the heat dissipation tube in the heat exchanger using a refrigerant acting under high pressure as a heat exchange medium, it is coupled to the header pipe to reduce the brazing joint The purpose is to provide a heat exchanger for carbon dioxide.

Another object of the present invention is to provide a heat exchanger for carbon dioxide which reduces the number of flow paths by improving the structure in which the heat dissipation tube and the header pipe are combined.

1 is a perspective view showing a conventional heat exchanger for carbon dioxide,

2 is an exploded perspective view illustrating the header pipe of FIG. 1;

3 is a perspective view showing a heat exchanger for carbon dioxide according to a first embodiment of the present invention;

4 is a cross-sectional view of FIG.

5 is a cross-sectional view showing a heat exchanger for carbon dioxide according to a second embodiment of the present invention;

6 is a front view showing a heat exchanger for carbon dioxide according to a third embodiment of the present invention;

7 is a perspective view showing a heat exchanger for carbon dioxide according to a fourth embodiment of the present invention.

<Brief description of symbols for the main parts of the drawings>

300 ... heat exchanger 310 ... header pipe

311 ... 1st compartment 321 ... 2nd compartment

314 ... Header 315 ... Tank part

317 ... First Tube Ball 327 ... Second Tube Ball

331 ... upper end cap 341 ... lower end cap

350 ... heat dissipation tube 351 ... first heat dissipation tube

352 ... 2nd heat dissipation tube 353 ... 3rd heat dissipation tube

354 ... first return 355 ... second return

360 ... heat dissipation

In order to achieve the above object, a heat exchanger for carbon dioxide according to an aspect of the present invention,

The header portion and the tank portion is made of a combination, therein the first and second header pipe having an independent compartment for inducing the flow of the refrigerant along the longitudinal direction;

A heat dissipation tube flowing inside the refrigerant and communicating with a compartment of the header pipe to form a heat exchange unit with them;

A refrigerant inlet pipe positioned at one end of the first header pipe to introduce a refrigerant;

And a refrigerant discharge pipe disposed at one end of the second header pipe to discharge the refrigerant.

The heat dissipation tube is disposed in a direction orthogonal to a direction in which a plurality of unit heat dissipation tubes flow, wherein at least two return portions are formed in a portion where the unit heat dissipation tubes are interconnected to form a single refrigerant flow path. It features.

The heat dissipation tube may include an odd number of unit heat dissipation tubes and an even number of return units formed in a direction in which air flows to connect the unit heat dissipation tubes.

In addition, the heat dissipation tube is characterized by consisting of an even number of unit heat dissipation tube and an odd number of return portions formed in a direction in which air flows to connect the unit heat dissipation tube.

Furthermore, the heat dissipation tube is disposed such that adjacent unit heat dissipation tubes have flow paths in different directions, and both ends of the heat dissipation tube are coupled to communicate with the first and second header pipes, respectively.

In addition, both ends of the heat dissipation tube is characterized in that coupled to the first and second header pipe having a predetermined angle slope.

Further, the heat dissipation tubes are arranged side by side in the horizontal direction in which the outside air flows and at the same time the return unit communicating the unit heat dissipation tubes in the horizontal direction so as to form a single refrigerant flow path in the vertical direction in which the flow path of the header pipe is formed. And a vertical horizontal complex type in which a single flow path is formed by at least one bending part communicating each unit heat dissipation tube vertically adjacent to each other along the longitudinal direction of the header pipe.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 illustrates a heat exchanger 300 for carbon dioxide according to a first embodiment of the present invention, and FIG. 4 illustrates a flow of a refrigerant in the heat exchanger 300 of FIG. 3.

3 and 4, in the heat exchanger 300, respective header pipes are disposed at both ends of the heat dissipation tube, and one channel of the refrigerant is formed at each end of the heat exchanger 300. To this end, the heat dissipation tube has an odd number of unit heat dissipation tubes and an even number of return parts connecting them.

More detailed description is as follows.

The heat exchanger 300 is provided with a first header pipe 310 and a second header pipe 320. In the first header pipe 310, a first compartment 311, which is a flow path of a refrigerant, is formed along a length direction thereof, and a second compartment 321 is formed in the second header pipe 320. . The first and second header pipes 310 and 320 are disposed in opposite directions, not in the same direction. The refrigerant inlet pipe 370 communicates with the first compartment 311, and the refrigerant discharge pipe 380 is installed in the second compartment 321.

The first header pipe 310 is coupled to the first header portion 314 and the first tank portion 315 to form the first compartment 311, the second header pipe 320 is a second The second header part 324 and the second tank part 325 are combined to form the compartment 321.

A first upper end cap 331 and a lower end cap 341 are installed at upper and lower ends of the first header pipe 310, and second upper ends are provided at upper and lower ends of the second header pipe 320. The cap 332 and the lower end cap 342 are provided. The first upper and lower end caps 331 and the second upper and lower end caps 332 and 342 are coupled to be sealed to the first header pipe 310 and the second header pipe 320. have.

In the first and second header portions 314 and 324, first tube holes 317 and second tube holes 327 are formed along the length direction thereof. The first and second tube holes 317 and 327 are formed to be spaced apart at predetermined intervals along the vertical direction of the first and second header parts 314 and 324.

At this time, both ends of the heat dissipation tube 350 are interposed between the first tube hole 317 and the second tube hole 327. The heat dissipation tube 350 has a structure in which a plurality of heat dissipation tubes 350 are stacked in a vertical direction of the heat exchanger 300, and a heat dissipation fin 360 is interposed on an outer surface of the heat dissipation tube 350.

The heat dissipation tube 350 may include a first heat dissipation tube 351 communicating with the first compartment 311, a third heat dissipation tube 353 coupled to the second compartment 321, and the first and the second heat dissipation tubes 350. A second heat dissipation tube 352 is disposed between the third heat dissipation tubes 351 and 353. In addition, the first and second heat dissipation tubes 351 and 352 are connected by a first return unit 354, and the second and third heat dissipation tubes 352 and 353 are second return units ( 355).

At this time, the first to third heat dissipation tubes 351 to 353 are arranged side by side in a direction orthogonal to the direction in which the outside air flows, and each of the tubes 351 to 353 has a first and second return unit 354 ( 355 is integrally connected to communicate with the passage through which the refrigerant flows.

That is, the first return part 354 is formed by bending the portion where the first heat dissipation tube 351 and the second heat dissipation tube 352 are connected, and the second return part 355 is the second heat dissipation tube. 352 and a portion to which the third heat dissipation tube 353 is connected are formed. The first and second return parts 354 and 355 form a U-shape such that the refrigerant is turnable in a state of low resistance. Accordingly, the first to third heat dissipation tubes 351 to 353 have a dead shape ( It is formed in a rectangular shape.

At this time, the end portion 351a of the first heat dissipation tube 351 is installed in communication with the first compartment 311, and the end 353a of the third heat dissipation tube 352 is connected to the second compartment 321. It is installed to communicate. In addition, the first return unit 354 is positioned in the direction in which the second compartment 321 is installed, and the second return unit 355 is disposed in the direction in which the first compartment 311 is installed.

As such, in the heat exchanger 300 for carbon dioxide according to the present invention, first and second header pipes 310 and 320 are positioned at both ends of the heat dissipation tube 350. In addition, since the first and second header pipes 310 and 320 are arranged to be separated from each other on both sides of the heat dissipation tube 350, each independent flow path is formed at each end of the heat dissipation tube 350. something to do.

The first to third heat dissipation tubes 351 to 353 are integrally connected to each other by the first and second return units 354 and 355 and communicate with the first compartment 311. The end portion 351a of the tube 351 and the end portion 353a of the third heat dissipation tube 353 communicating with the second compartment 321 are arranged in opposite directions, and are perpendicular to the direction in which the outside air flows. Direction.

In addition, the heat exchanger 300 using the high-pressure carbon dioxide as a refrigerant forms a plurality of independent flow paths so as to strengthen the internal pressure, and the cross-sectional area of the flow path is formed in a substantially circular or oval shape of a track.

The heat dissipation tube 350 having the above structure rotates the end of the first heat dissipation tube 351 by 90 degrees in the width direction, and then bends 180 degrees in the direction of the tube through which the refrigerant flows. 354 is formed, and then, the end portion of the second heat dissipation tube 352 is further rotated 90 degrees in the width direction to bend 180 degrees to form the second return portion 355, thereby forming the first to first integral parts. 3 to arrange the heat dissipation tubes (351 to 353). In this case, the first and second return parts 354 and 355 may be replaced with other shapes as long as the refrigerant turns, such as a V shape or a bent shape, in addition to the U shape.

Looking at the operation of the heat exchanger 300 having the configuration as described above are as follows.

First, the carbon dioxide refrigerant introduced through the refrigerant inlet pipe 370 is filled into the entire first compartment 311 and flows through the first heat dissipation tube 351 communicating with the first compartment 311.

The refrigerant flowing through the first heat dissipation tube 351 is turned into a U-shape while passing through the first return portion 354 connecting the first and second heat dissipation tubes 351 and 352. The U-turned refrigerant flows through the second heat dissipation tube 352. The refrigerant flowing through the second heat dissipation tube 352 is turned into a U-shape again via the second return part 355 connecting the second and third heat dissipation tubes 352 and 353. The refrigerant flows through the third heat dissipation tube 353 and flows into the second compartment 321 in communication with the third heat dissipation tube 353. The refrigerant introduced into the second compartment 321 is discharged through the refrigerant discharge pipe 380. At this time, the outside air to be heat exchanged with the refrigerant proceeds in a direction orthogonal to the direction in which the first to third heat dissipation tubes 351 to 353 are arranged as indicated by arrows.

5 shows a heat exchanger 500 for carbon dioxide according to a second embodiment of the present invention.

Referring to the drawings, the heat exchanger 500 is a case in which each header pipe is disposed only in one direction of the heat dissipation tube, and the flow path of the refrigerant is connected to both ends of the tube disposed in the same direction. To this end, the heat dissipation tube has an even number of unit heat dissipation tubes and an odd number of return parts connecting them.

The features of this embodiment are described as follows.

The heat exchanger 500 is provided with a first header pipe 510 and a second header pipe 520. In the first and second header pipes 510 and 520, first and second compartments 511 and 521, which are channels of refrigerant, are formed along the length direction. The first and second header pipes 510 and 520 are arranged in the same direction. The coolant inlet pipe 570 communicates with the first compartment 511, and the coolant discharge pipe 580 is connected to the second compartment 521. The first and second header pipes 510, 520 are respectively header parts 514, 525 and tank parts 515, 524 to form the first and second compartments 511, 521. Is combined.

Both ends of the heat dissipation tube 550 are interposed between the first and second header pipes 510 and 520. The heat dissipation tube 550 may include a first heat dissipation tube 551 communicating with the first compartment 511, a fourth heat dissipation tube 554 coupled with the second compartment 521, and the first and the second heat dissipation tubes. Fourth heat dissipation tube 554 consists of the 3rd and 4th heat dissipation tubes 552 and 553 which are arrange | positioned reversely mutually.

In addition, the first and second heat dissipation tubes 551 and 552 are integrally connected by a first return part 555, and the second and third heat dissipation tubes 552 and 553 are second return parts. 556 is integrally connected, and the third and fourth heat dissipation tubes 553 and 554 are connected by a third return part 557, so that the heat dissipation tube 550 is a channel of the refrigerant. It is a meander shape consisting of a single passage.

In this case, the first to fourth heat dissipation tubes 551 to 554 are arranged side by side in a direction orthogonal to the direction in which the outside air flows, as indicated by the arrows, and the first and third heat dissipation tubes 551 and 553. ) Have the same flow path direction, and the second and fourth heat dissipation tubes 552 and 554 also have the same flow direction. In addition, the first and third heat dissipation tubes 551 and 553 and the second and fourth heat dissipation tubes 552 and 554 have opposite flow path directions.

To this end, a portion of the first heat dissipation tube 551 and the second heat dissipation tube 552 is connected to the first and second heat dissipation tubes 551 and 552 by a U-shaped first return part 555. The flow path is bent so as to be in the opposite direction. The second and third heat dissipation tubes 552 and 553 are also bent by the second return unit 556, and the third and fourth heat dissipation tubes 553 and 554 are third return units ( 557).

At this time, the end portion 551a of the first heat dissipation tube 551 is installed in communication with the first compartment 511, and the end 554a of the fourth heat dissipation tube 554 is in the second compartment 521. It is installed to communicate.

As such, the heat exchanger 500 includes first and second header pipes 510 and 520 disposed in one direction of the heat dissipation tube 500. In addition, the first and second header pipes 510 and 520 may be formed with only two flow paths in which a refrigerant flows in and out of one end of the heat dissipation tube 550.

Further, even-numbered first to fourth heat dissipation tubes 551 to 554 are integrally connected by odd-numbered first to third return parts 555 to 557 and are in communication with the first compartment 511. The first heat dissipation tube 551 and the third heat dissipation tube 553 have the same flow path, and the fourth heat dissipation tube 554 and the second heat dissipation tube 552 communicating with the second compartment 521 have the same flow path. The heat dissipation tube 550 forms a direction orthogonal to a direction in which outside air flows.

Figure 6 shows a heat exchanger 600 for carbon dioxide according to a third embodiment of the present invention.

Unlike the embodiment described above, the bending of the heat dissipation tube 650 is integrally performed in the vertical direction of the heat dissipation tube 650 in order to reduce the number of tube holes 617 into which the heat dissipation tube 650 is inserted, thereby minimizing the brazing process. This is the case.

That is, the heat exchanger 600 is provided with a header pipe 610. A plurality of header pipes 610 are spaced apart from each other, and a compartment 611 is formed in each header pipe 610 to provide an independent flow space of the refrigerant. An upper end cap 631 is installed at an upper end of the header pipe 610, and a lower end cap 641 is sealed at a lower end.

The header pipe 610 is formed in plural so that the tube holes 617 are spaced apart by a predetermined interval along the longitudinal direction thereof. The end of the heat dissipation tube 650 is interposed in the tube hole 617.

In this case, the heat dissipation tube 650 is bent in the vertical direction as well as the return portion 655 is formed as described above, in order to reduce the number of tube holes 617.

That is, the heat dissipation tube 650 is made of a U-turn unit heat dissipation tube to be coupled to an adjacent header pipe (not shown) by the return unit 655, and as shown in the first to third heat dissipation tubes in the vertical direction. It has a structure bent in a horizontal and vertical composite having a bending portion 654 to form (651 to 653).

Accordingly, the heat exchanger 600 reduces the number of cases in which the heat dissipation tube 650 is coupled to the tube hole 617 by about one third.

7 is a heat exchanger 700 for carbon dioxide according to a fourth embodiment of the present invention.

Referring to the drawings, the heat exchanger 700 is provided with a header pipe 710 forming first and second compartments 711 and 712 that are independent of each other. The header pipe 710 is combined with a header portion 714 and a tank portion 715 to form first and second compartments 711 and 712. In order to partition the first and second compartments 711 and 712, a partition wall 716 is formed at an intermediate portion, and a portion 716a to be caulked is formed at the partition wall 716.

First and second tube holes 717 and 718 are formed in the header part 714 along the length thereof, and the first and second tube holes 717 and 718 are respectively formed in the header part ( 714 is spaced apart from each other in the vertical direction. Ends 755 and 756 of the first heat dissipation tube 751 and the second heat dissipation tube 752 may be interposed in the tube holes 717 and 718. The first and second heat dissipation tubes 751 and 752 are not shown, but as can be seen in the above embodiment, the return portion forms a single refrigerant flow path. In addition, at least one microtube passage 754 is formed in the first and second heat dissipation tubes 751 and 752 along its length direction.

According to the present embodiment, the tube holes 717 and 718 of the header portion 714 and the end portions 755 and 756 of the heat dissipation tube 750 inserted therein are formed to be inclined at a predetermined angle. have.

To prevent this, the ends 755 and 756 of the first and second heat dissipation tubes 751 and 752 are twisted at an angle of 90 degrees or less. In addition, the first and second tube holes 717 and 718 into which the first and second heat dissipation tubes 751 and 752 are inserted are also inclined at the header portion 714 at a corresponding angle. .

When the inclination angles of the first and second tube holes 717 and 718 become 90 degrees, the interference between the tube spaces arranged in the vertical direction of the tank part 714 may occur. It is desirable to form it to have an inevitable rotation angle.

Thus, since the first and second heat dissipation tubes 751 and 752 are twisted at an angle of 90 degrees or less, the first and second compartments 711 and 712 into which the end portions 755 and 756 are inserted. The inner flow passage will be able to reduce the internal volume by the existence of a space by the inclined angle.

As described above, the heat exchanger for carbon dioxide of the present invention can obtain the following effects.

First, since the heat dissipation tube coupled to the header pipe has one single flow passage by the return portion, the flow path number of the refrigerant coupled thereto is reduced. As a result, as the brazing joint is reduced, leakage of the high pressure refrigerant can be reduced.

Second, as the number of tube holes of the header pipe to which the heat dissipation tube is coupled is reduced, the brazing joint is reduced.

Third, in the refrigerant passage of the header pipe, only the portion where the refrigerant flows in and the portion where the refrigerant flows are required, so that the structure is simple and the weight is reduced.

Fourth, as the distance between adjacent tubes is reduced, it is possible to manufacture a compact heat exchanger.

Fifth, since the tube hole of the header pipe and the heat dissipation tube inserted into the tube hole are inclined at a predetermined angle, the flow path width of the refrigerant can be reduced by the angle at which the heat dissipation tube is inclined. Thereby, the flow volume of a header pipe can be reduced significantly.

Sixth, the pressure resistance is greatly improved by reducing the flow volume of the header pipe.

Seventh, since the end of the tube is inclined at a predetermined angle inside the header pipe, the resistance to the flow of the refrigerant can be greatly reduced.

Eighth, as the distance between the tubes decreases in the header pipe with the dividing wall, it is possible to manufacture a compact heat exchanger.

Ninth, each of the independent flow paths is formed, and since the cross section is formed into a circular or track-shaped ellipse, the pressure resistance of the heat exchanger using high pressure carbon dioxide as a refrigerant can be improved.

Although the present invention has been described with reference to the embodiments illustrated in the accompanying drawings, it is merely exemplary, and those skilled in the art may realize various modifications and other equivalent embodiments therefrom. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (6)

The header portion and the tank portion is made of a combination, therein the first and second header pipe having an independent compartment for inducing the flow of the refrigerant along the longitudinal direction; A heat dissipation tube flowing inside the refrigerant and communicating with a compartment of the header pipe to form a heat exchange unit with them; A refrigerant inlet pipe positioned at one end of the first header pipe to introduce a refrigerant; And a refrigerant discharge pipe disposed at one end of the second header pipe to discharge the refrigerant. The heat dissipation tube is disposed in a direction orthogonal to a direction in which a plurality of unit heat dissipation tubes flow, wherein at least two return portions are formed in a portion where the unit heat dissipation tubes are interconnected to form a single refrigerant flow path. Heat exchanger for carbon dioxide, characterized in that. The method of claim 1, The heat dissipation tube is a heat exchanger for carbon dioxide, characterized in that consisting of an odd number of unit heat dissipation tube and an even number of return portions formed in a direction in which air flows to connect the unit heat dissipation tube. The method of claim 1, The heat dissipation tube is a heat exchanger for carbon dioxide, characterized in that it consists of an even number of unit heat dissipation tube and an odd number of return portions formed in a direction in which air flows to connect the unit heat dissipation tube. The method of claim 2 or 3, The heat dissipation tube is disposed such that adjacent unit heat dissipation tubes have flow paths in different directions, and both ends of the heat dissipation tube are coupled to communicate with the first and second header pipes, respectively. . The method of claim 1, And both ends of the heat dissipation tube are coupled to the first and second header pipes at predetermined angles. The method of claim 1, The heat dissipation tube may be arranged side by side in the horizontal direction in which the outside air flows, and at the same time, the return unit communicating the unit heat dissipation tubes in the horizontal direction to form a single refrigerant flow path in the vertical direction in which the flow path of the header pipe is formed; The vertical heat exchanger for the carbon dioxide, characterized in that a vertical flow path is formed by at least one bending portion for communicating each unit heat dissipation tube up and down adjacent in the longitudinal direction of the header pipe.