KR20030092214A - Combination structure of heat exchanger for using CO2 as a refrigerant - Google Patents

Abstract

PURPOSE: A structure for coupling a header pipe of a heat exchanger for oxygen dioxide is provided to allow the heat exchanger to endure oxygen dioxide refrigerant with high working pressure without largely changing a usual structure of the heat exchanger. CONSTITUTION: A plurality of insertion grooves(128a) are formed on an end of a second partition(128) of a header(123) in longitudinal direction in such a manner that the insertion grooves penetrate the second partition. A plurality of ribs(127a) are protrusively formed on an end of a first partition(127) of a tank(122) to be inserted and coupled to the insertion grooves and protruded from outsides of the insertion grooves. The ribs protruded from the outside of the insertion grooves are pressurized to form caulking parts so as to couple and fix the header and the tank. The rib is formed on the end of the first partition as long as the first partition when the tank is manufactured by extrusion. The rib is removed except for a part thereof inserted to the insertion groove of the header.

Description

Combination structure of heat exchanger for using CO2 as a refrigerant}

The present invention relates to a header pipe coupling structure of a heat exchanger for carbon dioxide, and more particularly, to prevent breakage due to high pressure and to improve brazing property by combining the tanks of the header pipe constituting the heat exchanger with the respective partition walls of the header. A header pipe coupling structure of a heat exchanger for carbon dioxide.

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. HFC refrigerants have been mainly used as an operating medium for air conditioner systems having such heat exchangers. However, the 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 the next generation carbon dioxide refrigerant to replace the HFC refrigerant is being actively conducted.

Carbon dioxide, the representative of such next-generation refrigerants, corresponds to about one-third 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 due to the low operating compression ratio, and the heat transfer performance is so excellent 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 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 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 static 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 former 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 the carbon dioxide, which is the refrigerant when the refrigerant is cooled, is heat exchanged. Since there is no condensation process in the air, the temperature is continuously lowered, and thus, a temperature deviation in the entire heat exchanger is increased so that heat flows itself along the surface of the heat exchanger through tubes and fins. This heat flow prevents the refrigerant from exchanging heat with the external inlet air and naturally reduces the heat exchange performance.

The latter multi slab method allows a plurality of rows of tubes to be arranged so that the refrigerant conducts heat exchange as it passes through the columns of the tubes, which can block heat flow like the multi-pass method, and thus operate at a high pressure such as carbon dioxide. In a heat exchanger using a refrigerant to be known as a better structure,

However, such a multi slab heat exchanger has to 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.

Therefore, in the related art, a heat exchanger having a large thickness so as to withstand only a high operating pressure without considering the refrigerant characteristics of the carbon dioxide has been used as a heat exchanger for carbon dioxide.

As shown in FIGS. 1 to 4, the multi-slab type carbon dioxide heat exchanger 1 is disposed in parallel to each other and the first and second header pipes 10 and 20 are sealed at both ends, and It consists of a plurality of tubes 50 for connecting the first and second header pipes 10 and 20 so as to communicate with each other, and a plurality of heat dissipation fins 60 provided between the tubes 50.

First, the first header pipe is formed between a plurality of flow paths 14a and 15a and has a tank 12 having a first partition wall 17 having a predetermined thickness that separates the flow paths 14a and 15a, The first flow paths 14a and 15b of the tank 12 and the flow paths 14b and 15b facing the first partition wall 17 and the header 13 on which the second partition wall 18 are formed are mutually coupled to each other. The first and second single channels 14 and 15 are independent of each other by the first and second partition walls 17 and 18, and the upper and lower parts thereof are sealed by the cap 11.

The second header pipe 20 is formed between a plurality of flow paths 24a and 25a and has a first partition wall 27 having a constant thickness for dividing the flow paths 24a and 25a. ) And the headers 23 formed with the flow paths 24b and 25b facing each of the flow paths 24a and 25a of the tank 22 and the first partition wall 27 and the second partition wall 28. Thus, the first and second partition walls 27 and 28 have third and fourth single channels 24 and 25 independent from each other, and upper and lower portions thereof are sealed by the cap 21 so that the first header pipe 10 and A communication hole 29 is disposed to be spaced apart from each other at predetermined intervals and to communicate the third and fourth single channels 24 and 25 with each other.

In addition, the tube 50 communicates the first single channel 14 and the third single channel 24, and the second single channel 15 and the fourth single channel 25 communicate with each other. It is installed to flow.

The heat dissipation fins 60 are installed between the respective tubes 50 to allow the refrigerant flowing in the tubes 50 to smoothly exchange heat with air.

In addition, the refrigerant inlet pipe 30 is formed in the first header pipe 10 and the refrigerant is introduced, and the refrigerant outlet pipe 40 is formed in the first header pipe 10, the refrigerant flows out. do.

Referring to the flow of the refrigerant flowing inside the heat exchanger 1 for the carbon dioxide is as follows.

The refrigerant introduced through the refrigerant inlet pipe 30 formed in the first single channel 14 flows into the entire first single channel 14, and the refrigerant flows through the first tube row 50a to the second header pipe ( 20 flows to the third single channel 24. The refrigerant introduced into the third single channel 24 is returned to the fourth single channel 25 through the communication hole 29 communicating the third single channel 24 and the fourth single channel 25. It flows into the 2nd single channel 15 through the 2 tube row | line 50b. The refrigerant introduced into the second single channel 15 is discharged through the refrigerant outlet pipe 40.

The heat exchanger 1 for carbon dioxide is the first and second partitions 17, 18, and 27 of the tanks 12 and 22 and the headers 13 and 23 due to the tensile force due to the high operating pressure therein. The thickness of 28) is made thicker than the thickness of the outer portion. Therefore, it can withstand high operating pressure.

However, the above-described heat exchanger 1 for carbon dioxide is used for the first partitions 17 and 27 of the tanks 12 and 22 and the second partitions 18 and 28 of the headers 13 and 23. Since the joining surface is only in surface contact, gaps may be exceeded in the manufacturing process, assembly, or conveying process. Therefore, perfect brazing may not be possible, thereby increasing the defective rate.

In addition, when a high operating pressure is applied there is a problem that the fracture proceeds from the gap.

An object of the present invention for solving the above-described problems is to provide a heat exchanger having a structure that can withstand a carbon dioxide refrigerant having a high operating pressure without significantly changing the structure of the conventional heat exchanger.

Still another object is to provide a heat exchanger which further improves brazing property by coupling / fixing each partition wall of the header pipe tank and the header by the ribs.

In order to achieve the above object, the present invention is formed between a plurality of flow paths and having a partition for partitioning the respective flow paths, the flow path and partition walls facing each of the flow paths and partitions of the tank and the each flow path In the header pipe coupling structure of the heat exchanger for carbon dioxide comprising a header pipe consisting of a header to form a single channel, the coupling means are formed integrally on the partition wall of the tank and the header, respectively.

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

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

3 is an exploded perspective view of the second header pipe in FIG. 1;

4 is a cross-sectional view taken along the line A-A in FIG.

5 is a perspective view showing a heat exchanger for carbon dioxide of the present invention,

6 is an exploded perspective view of a first header pipe of the present invention;

7 is an exploded perspective view of a second header pipe of the present invention;

8 is a cross-sectional view taken along line B-B in FIG. 5;

FIG. 9 is a cross-sectional view of the tank and the header fixed by crimping the caulking rib protruding to the outside of the header in FIG.

<Code Description of Main Parts of Drawing>

1: heat exchanger for carbon dioxide 50: tube

50a: first tube row 50b: second tube row

60: heat sink fin 100: heat exchanger for carbon dioxide

110: first header pipe 111,121: cap

112, 122: tank 113,123: header

114: first single euro

114a, 114b, 115a, 115b, 124a, 124b, 125a, 125b: Euro

115: second single channel 116, 126: tube hole

117, 127: first partition 117a, 127a: rib

118,128: 2nd bulkhead 118a, 128a: insertion groove

120: second header pipe 124: third single channel

125: fourth single channel 127b: caulking unit

129: communication hole 130: refrigerant inlet pipe

140: refrigerant outlet pipe 150: coupling means

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

The same components as in the related art are denoted by the same reference numerals, and redundant descriptions are omitted.

5 is a perspective view showing a heat exchanger for carbon dioxide of the present invention, Figure 6 is an exploded perspective view of the first header pipe of the present invention, Figure 7 is an exploded perspective view of the second header pipe of the present invention, Figure 8 is a view 5 is a cross-sectional view taken along line BB, and FIG. 9 is a cross-sectional view of the rib that protrudes to the outside of the header in FIG. 8 by pressing the tank and the header.

The present invention is formed between a plurality of flow paths and having a partition for partitioning each of the flow paths, flow paths and partitions facing each of the flow paths and partitions of the tank are formed, and the flow path is formed so that each of the flow path is formed as a single flow path A header pipe coupling structure of a heat exchanger for carbon dioxide including a header pipe composed of a header coupled by a tank and coupling means, wherein the header pipe is composed of a first header pipe and a second header pipe of the present invention.

Hereinafter, the overall configuration of the first and second header pipes of the heat exchanger for carbon dioxide of the present invention will be described first before explaining the coupling structure of the present invention.

As shown, the heat exchanger 100 for carbon dioxide of the present invention is disposed in parallel with each other and the first and second header pipes 110 and 120 are sealed at both ends, and the first and second header pipes 110 ) Is composed of a plurality of tubes (50) for connecting to communicate with each other, and a plurality of heat radiation fins (60) provided between the tubes (50).

First, the first header pipe 110 is formed between a plurality of flow paths 114a and 115a and has a tank 112 having a first partition wall 117 having a predetermined thickness that separates the flow paths 114a and 115a. And a header 113 formed with flow paths 114b and 115b and second partitions 118 facing the flow paths 114a and 115a and the first partition wall 117 of the tank 112. The first and second single flow passages 114 and 115 which are mutually coupled to each other by the first and second partitions 117 and 118 are separated from each other by the first and second partitions 117 and 118, and the upper and lower portions are sealed by the cap 111.

In addition, a refrigerant inlet pipe 130 is installed at an upper portion of the first single channel 114 of the first header pipe 110, and a refrigerant outlet tube 140 is installed at a lower portion of the second single channel 115.

The second header pipe 120 is formed between the plurality of flow paths 124a and 125a and has a tank 122 having a first partition wall 127 having a predetermined thickness that separates the flow paths 124a and 125a. And a header 123 having flow paths 124b and 125b and second partitions 128 opposed to the flow paths 124a and 125a and the first partition wall 127 of the tank 122. The third and fourth single flow paths 124 and 125 which are mutually coupled by the first and second partitions 127 and 128 and are separated from each other by the first and second partitions 127 and 128, and the upper and lower parts are sealed by the cap 121, The first header pipe 110 is spaced apart from each other at a predetermined distance and arranged in parallel, and the tank 122 has a communication hole 129 for communicating the third and fourth single channels 124 and 125 with each other.

The tube 50 communicates the first single channel 114 and the third single channel 124 between the first header pipe 110 and the second header pipe 120, and the second single channel ( 115 and tube holes 116 on the side of each header 113 and 123 of the first and second header pipes 110 and 120 so that the refrigerant flows into the fourth single channel 125. Plural numbers are provided at 126.

In addition, the heat dissipation fin 60 is installed between the tubes 50 to allow the refrigerant flowing in the tube 50 to smoothly exchange heat with air, which is the second heat exchange medium.

Meanwhile, the coupling means 150 will be described with reference to the second header pipe 120 as shown in FIGS. 8 to 9.

A plurality of insertion grooves 128a are arranged at regular intervals in the longitudinal direction such that both ends penetrate through ends of the second partition wall 128 of the header 123, and the first partition wall 127 of the tank 122 At the end, a plurality of ribs 127a are inserted / coupled to the insertion groove 128a to protrude outwardly of the insertion groove 128a, and the ribs 127a protruding outward of the insertion groove 128a are formed. Compression forms the caulking portion 127b to couple / fix the header 123 and the tank 122.

Here, the rib 127a is formed at the end of the first partition 127 at the end of the first partition 127 when the tank 122 is manufactured by extrusion, and then the header 123 is formed. Except for the portion to be inserted into the insertion groove (128a) of all will be formed by removing.

In addition, the coupling means 150 is also applied to the first header pipe 110 in the same manner, and in the above, the insertion groove 128a is formed in the second partition wall 128 of the header 123 and the tank 122 Although the rib 127a is formed in the first partition 127, the rib 127a is formed in the second partition 128 of the header 123 and the first partition 127 of the tank 122 is formed. Of course, it is also possible to form the insertion groove (128a) in.

In addition, the first header pipe 110 prevents the independent first single channel 114 and the second single channel 115 from communicating with each other.

In particular, in the heat exchanger 100 using carbon dioxide as the refrigerant, since the first and second header pipes 110 and 120 need to be able to withstand high pressure, the headers 113 and 123 according to the present invention. ) Is manufactured by pressing, and tanks 112 and 122 are manufactured by extrusion and joined by brazing.

At this time, in order to improve the brazing property, the coupling means 150 as described above, that is, the tanks 112 and 122 are formed with ribs 117a and 127a and the insertion grooves 118a in the headers 113 and 123. After forming and coupling the 128a, the portions of the ribs 117a and 127a protruding outward from the headers 113 and 123 are pressed and fixed to perform brazing.

In the carbon dioxide heat exchanger 100, the single channel 114, 115, 124, 125 and the tubes 50 form a slab, the first single channel 114 and the third channel. The first tube stream 50a communicating with the single channel 124 and the first and third single channels 114 and 124 form one slab, and the second single channel 115 and the fourth single channel ( The second tube row 50b communicating 125 and these second and fourth single flow paths 115 and 125 form another slab.

Therefore, the refrigerant introduced through the refrigerant inlet pipe 130 attached to the first single channel 114 is heat-exchanged through the slab composed of the first and third single channels 114 and 124 and the first tube row 50a. This is done, and returned from the second header pipe 120 to exchange heat again through the slab consisting of the second and fourth single channels 115 and 125 and the second tube row 50b, and then the second single channel 115 It is to flow through the refrigerant outlet pipe 140 provided in). At this time, as can be seen in Figure 5, the heat exchanger 100 is such that the air flows from the side where the outlet pipe 140 of the refrigerant is installed can increase the overall heat exchange efficiency, the heat exchanger 100 refrigerant It is preferable that the outlet pipe 140 is disposed so as to face the direction in which the air enters.

Referring to the refrigerant flow of the carbon dioxide heat exchanger 100 having the above configuration in more detail as follows.

As shown in FIG. 4, the refrigerant introduced through the refrigerant inlet pipe 130 formed in the first single channel 114 flows into the entire first single channel 114, and the refrigerant flows through the first tube row 50a. ) Flows into the third single channel 124 of the second header pipe 120. The refrigerant introduced into the third single channel 124 is returned to the fourth single channel 125 through a communication hole 129 that communicates the third single channel 124 and the fourth single channel 125. It is introduced into the second single channel 115 through the two tube rows (50b). The refrigerant introduced into the second single channel 115 is discharged through the refrigerant outlet pipe 140. At this time, the air to be heat-exchanged with the refrigerant is introduced from the second tube row 50b side, and first heat-exchanges with the refrigerant flowing through the second tube row 50b, and the air and the first tube row 50a at which the temperature rises to a certain degree are increased. As the heat exchange is performed, heat exchanger efficiency can be improved by arranging the heat exchanger to face the refrigerant flow and the air flow direction. Therefore, the heat exchange efficiency of the heat exchanger 100 can be increased as a whole.

In addition, the tanks 112 and 122 and the headers 113 and 123 of the first and second header pipes 110 and 120 are connected to the tanks 112 and 122 by the coupling means 150. (113) (123) will have a perfect coupling structure.

Therefore, the tanks 112 and 122 and the headers 113 and 123 of the first and second header pipes 110 and 120 are not separated even during the manufacturing process, the assembly process, or the transfer process. Since the gap between the joint surface of the header 113 and 123 can be maintained as it is minimized, it will have a more rigid coupling structure and thus the brazing can be perfected.

The heat exchanger 100 for carbon dioxide having the bonding structure of the present invention described above not only improves brazing property, but also can withstand high operating pressure therein.

As described above, the coupling structure of the heat exchanger 100 for carbon dioxide of the present invention has been described for the convenience of a two-row multi-slab type heat exchanger for convenience, three rows, four rows, etc. through the coupling structure of the same method Of course, it can be applied to all types of multi slab heat exchanger.

According to the present invention, a plurality of ribs formed in the first partition of the tank of the header pipe is inserted / coupled to the plurality of insertion grooves formed in the second partition of the header crimped ribs protruding outward of the insertion groove. By having a coupling structure that is fixed by fixing, the brazing property can be improved and the defect rate can be significantly reduced.

In addition, the coupling structure can withstand the high operating pressure acting inside the heat exchanger to prevent the breakage of the header pipe.

Claims (5)

A tank formed between a plurality of flow paths and having a partition wall for dividing the flow paths, and a header for forming a flow path and a partition wall facing the flow paths and partition walls of the tank and forming the flow paths in a single flow path. In the header pipe coupling structure of the heat exchanger for carbon dioxide comprising a header pipe, Coupling structure of the header pipe of the heat exchanger for carbon dioxide, characterized in that the coupling means are integrally formed in each of the partition walls of the tank and the header. The method of claim 1, The coupling means has an insertion groove is formed in any one of the partition of the tank and the header, the other rib is formed in the header pipe coupling structure of the heat exchanger for carbon dioxide, characterized in that the rib is inserted into the insertion groove. The method of claim 2, And a caulking portion is formed at the end of the rib so as not to be separated from the insertion groove. The method of claim 2, The rib and the insertion groove is a header pipe coupling structure of the heat exchanger for carbon dioxide, characterized in that formed in the tank and the header at least two or more in the longitudinal direction at regular intervals. The method according to any one of claims 1 to 4, And a communication hole for communicating the flow path in the partition wall of the tank.