KR100893354B1 - Internal heat exchanger for using CO2 as a refrigerant - Google Patents

Abstract

The present invention relates to an internal heat exchanger for carbon dioxide, and more particularly, for carbon dioxide to improve cooling performance by mutually heat-exchanging a gas cooler outlet refrigerant and an evaporator outlet refrigerant in a refrigerant system using carbon dioxide (CO ₂ ) as a refrigerant. It relates to an internal heat exchanger.

Accordingly, in the present invention, helical first and second refrigerant passages 21 and 22 are formed to be opposed to each other with a spiral partition 23 interposed therebetween, so that each refrigerant passage 21 ( The internal heat exchanger body 20 and the internal heat exchanger body 20 which are capable of mutual heat exchange as the same or different types of the first refrigerant and the second refrigerant are respectively flowed in the inside 22 and the open sides of the internal heat exchanger body 20 are respectively installed. The first and second end plates 30 and 40 determine the positions of the inlet and the outlet 21a, 21b, 22a, and 22b of the first and second refrigerant paths 21 and 22, respectively.

Heat exchanger, refrigerant, carbon dioxide, refrigerant flow path, evaporator, gas cooler

Description

Internal heat exchanger for using CO2 as a refrigerant

1 is a schematic cross-sectional view showing a heat exchanger having a conventional general double flow path,

2 is an exploded perspective view showing an internal heat exchanger for carbon dioxide having a double flow path according to a first embodiment of the present invention;

Figure 3 is a cross-sectional view showing the internal heat exchanger body for carbon dioxide in Figure 2,

4 is an exploded perspective view of an internal heat exchanger for carbon dioxide having a double channel according to a second embodiment of the present invention;

5 is an exploded perspective view of an internal heat exchanger for carbon dioxide having a double channel according to a third embodiment of the present invention;

6 is an exploded perspective view showing an internal heat exchanger for carbon dioxide having a double channel according to a fourth embodiment of the present invention;

FIG. 7 is a cross-sectional view illustrating an internal heat exchanger body for carbon dioxide in FIG. 6.

<Code Description of Main Parts of Drawing>

10: internal heat exchanger 20: internal heat exchanger body

20a, 20b: unit heat exchanger 21: first refrigerant flow path

21a: first refrigerant flow passage inlet 21b: first refrigerant flow passage inlet                 

22: second refrigerant passage 22a: second refrigerant passage inlet

22b: second refrigerant flow path outlet 23: partition wall

24: bridge 30: first end plate

31: first refrigerant inlet hole 32: second refrigerant inlet hole

33,41: first refrigerant discharge hole 34,42: second refrigerant discharge hole

35: refrigerant pipe 40: second end plate

50: refrigerant flow path conversion member 51: the first connection port

52: second connection port 60: first end cap

61: first inflow port 62: second inflow port

70: second end cap 71: first discharge port

72: second discharge port

The present invention relates to an internal heat exchanger for carbon dioxide, and more particularly, for carbon dioxide to improve cooling performance by mutually heat-exchanging a gas cooler outlet refrigerant and an evaporator outlet refrigerant in a refrigerant system using carbon dioxide (CO ₂ ) as a refrigerant. It relates to an internal heat exchanger.

CFC refrigerants, commonly referred to as freon gases, are known to destroy the ozone layer and are emerging as environmental issues at home and abroad, and new alternative refrigerants have been developed in advanced countries to minimize them.

Carbon dioxide (CO ₂ ) is a good stability, odorless, non-toxic, non-corrosive, non-combustion, non-explosive substance in the alternative refrigerant as described above, has a good compatibility with lubricating oil, and the small volume of gas compared to other refrigerants The system is easy to manufacture.

In addition, the biggest feature of carbon dioxide is to have a high vapor pressure and a low critical temperature.

Due to the high steam pressure and the low critical temperature, the carbon dioxide refrigerant system constitutes a supercritical cycle that absorbs heat at a pressure lower than the critical pressure and releases heat at a pressure higher than the critical pressure (supercritical state). The main components consist of a compressor, a gas cooler, an internal heat exchanger, an expansion valve, and an evaporator.

Since the efficiency of the cycle is influenced by the control of the gas cooler area, it is necessary to control the refrigerant flow rate during the throttling by sensing the temperature and pressure of the gas cooler outlet refrigerant. Since the temperature of the outlet refrigerant should be kept as low as possible, an internal heat exchanger that exchanges heat between the gas cooler outlet refrigerant and the evaporator outlet refrigerant is essential.

As an example of such a conventional internal heat exchanger (1), as shown in Figure 1, it is made of a case 2 of a sealed container type, the case (2) inlet 3 through which refrigerant from the evaporator flows in and out And an outlet 4 are formed.

The case 2 is configured to accommodate a thermally conductive coil conduit 5 through which refrigerant from a gas cooler passes.

Therefore, the refrigerant discharged from the evaporator and the refrigerant discharged from the gas cooler are mutually heat exchanged in the case 2.

Thus, the refrigerant discharged from the gas cooler is cooled by dissipating heat to the refrigerant discharged from the evaporator, and the cooled refrigerant becomes a complete liquid state and flows into the expansion valve to expand under reduced pressure.

In addition, the refrigerant evaporated in the evaporator is heated by mutual heat exchange with the refrigerant discharged from the gas cooler and returned to the compressor.

However, the conventional internal heat exchanger (1) of the above structure is not good heat exchange efficiency to increase the size of the internal heat exchanger (1) to increase the heat exchange efficiency, thereby increasing the weight and the structure is also complicated problem There was a weak problem, even pressure resistance.

SUMMARY OF THE INVENTION An object of the present invention for solving the conventional problems as described above is to provide an internal heat exchanger for carbon dioxide that reduces the weight by simplifying the structure of the internal heat exchanger and reduces its size and improves pressure resistance and heat exchange efficiency.

In order to achieve the above object, the present invention provides a spiral first and second refrigerant paths which are opposed to each other with a spiral bulkhead interposed therebetween in an open cylinder of both ends, so that the first and second types of first and second types of refrigerants are in each refrigerant path. An internal heat exchanger body capable of mutual heat exchange as the and second refrigerants flow, respectively; It is characterized by consisting of the first and second end plates which are respectively installed on both open sides of the internal heat exchanger body to determine the inlet and outlet positions of the first and second refrigerant passages.

In addition, both open types are formed by connecting a plurality of unit heat exchangers each having a spiral first and second refrigerant flow paths formed therein so as to allow heat exchange while the first and second refrigerants of the same type or the same type flow in the cylinder. Internal heat exchanger body; A first end plate installed at one open side of the internal heat exchanger body and having first and second refrigerant inlet holes formed therein to allow the first and second refrigerants to flow into the first and second refrigerant passages, respectively; A second end plate installed on the other open side of the internal heat exchanger body and having first and second refrigerant discharge holes through which first and second refrigerants are discharged from each of the first and second refrigerant passages; And a refrigerant flow converting member interposed between the unit heat exchangers and having first and second connection ports formed at positions different from the first and second refrigerant inlet holes to change the flow direction of the first and second refrigerants. It is done.

In addition, a plurality of bridges are formed between the first coolant flow path and a first coolant flow path through which the first coolant flows, and a partition wall is formed along the first coolant flow path to form a single helical passage inside the cylinder having both ends open. An internal heat exchanger body which is partitioned by a second refrigerant flow passage having a passage so that the second refrigerant flows in a straight line so that mutual exchange of heat is possible as the first and second refrigerants respectively flow; A first end plate installed at an open side of the internal heat exchanger body and having first and second refrigerant inlet holes formed therein to allow the first and second refrigerants to flow into the first and second refrigerant passages, respectively; A second end plate installed at the other open side of the internal heat exchanger body and having first and second refrigerant discharge holes through which the first and second refrigerants passing through the first and second refrigerant passages are discharged; A first end cap installed at an outer side of the first end plate and having first and second inflow ports so as to separately enter the first and second refrigerants into each refrigerant inlet hole; And a second end cap installed at an outer side of the second end plate and having first and second discharge ports for dividing the first and second refrigerants discharged from each refrigerant discharge hole and discharging them to the outside. .

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

The same parts as in the prior art are denoted by the same reference numerals, and repeated description thereof will be omitted.

2 is an exploded perspective view illustrating an internal heat exchanger for carbon dioxide having a double flow path according to a first embodiment of the present invention, and FIG. 3 is a cross-sectional view illustrating an internal heat exchanger body for carbon dioxide in FIG. 2.

As shown, the internal heat exchanger 10 of the present invention has a spiral first and second refrigerant flow passages 21 and 22 opposed to each other with a spiral partition wall 23 interposed therebetween in a cylinder having both ends open. The internal heat exchanger body 20 and the open and open sides of the internal heat exchanger body 20 are respectively provided, and the inlet and outlet 21a, 21b and 22a of the first and second refrigerant flow passages 21 and 22 are formed. 22b, the first and second end plates 30 and 40 determine the position.

Here, the first and second refrigerant passages 21 and 22 having the spiral winding form the first and second refrigerant passages 21a, 21b and 22a (the first and the second refrigerant passages whose first and end portions are enlarged in a substantially circular shape). 22b) is formed.

In addition, the internal heat exchanger body 20 is preferably manufactured by an extrusion process.

The first end plate 30 is configured to allow the first refrigerant and the second refrigerant to flow into the inlets 21a and 22a of the first refrigerant passage 21 and the second refrigerant passage 22, respectively. First and second refrigerant inlet holes 31 and 32 are formed, and the first and second refrigerants passing through the first and second refrigerant passages 21 and 22 are at the outlets 21b and 22b. First and second refrigerant discharge holes 33 and 34 are formed so as to be discharged through each.

In addition, the second end plate 40 is closed to a certain thickness to seal one side of the internal heat exchanger body 20.

In addition, separate refrigerant pipes 35 are integrally formed in each of the refrigerant inlet holes 31 and 32 and the refrigerant discharge holes 33 and 34 of the first end plate 30 to allow each refrigerant to flow therethrough. It will be provided as a separate type.

Accordingly, the first refrigerant passage 21 of the internal heat exchanger body 20 may have the same or different types of first and second refrigerants through the refrigerant inlet holes 31 and 32 of the first end plate 30. And flows into the inlets 21a and 22a of the second refrigerant passage 22 and flows in a spiral direction in each of the refrigerant passages 21 and 22, whereby the second end plate 40 As the first and second refrigerants close one side of the internal heat exchanger body 20, the outlets 21b and 22b opened by the refrigerant discharge holes 33 and 34 of the first end plate 30 are closed. Is discharged through the flow to the refrigerant pipe 35 connected to the refrigerant discharge holes 33, 34 side of the first end plate (30).

In addition, the first and second refrigerants exchange heat with each other through the partition walls 23 while contacting the partition walls 23 partitioning the first and second refrigerant passages 21 and 22. ) Is constructed so that its contact area becomes very large as it becomes spiral. Therefore, the heat exchange efficiency can be improved by increasing the contact area.

4 is an exploded perspective view of an internal heat exchanger for carbon dioxide having a double flow path according to a second embodiment of the present invention, and only a configuration different from the above-described embodiment will be omitted.

As illustrated, the internal heat exchanger body 20 having the same structure as that of the first embodiment and the open side of the internal heat exchanger body 20 are respectively installed, and the first and second refrigerant flow passages 21 and 22 are respectively provided. The first and second end plates 30 and 40 determine the positions of the inlet and the outlet 21a, 21b, 22a and 22b, and the first end plate 30 is connected to the first refrigerant. First refrigerant inlets 31 and 32 are formed to allow the second refrigerant to flow into the inlets 21a and 22a of the first refrigerant passage 21 and the second refrigerant passage 22, respectively.

In the second end plate 40, the first and second refrigerants introduced to the inlets 21a and 22a flow in the spiral direction in the first refrigerant passage 21 and the second refrigerant passage 22. After the heat exchange while moving, the first and second refrigerant discharge holes 41 and 42 are formed to be discharged to each of the outlets 21b and 22b.

That is, the first and second refrigerant inlet holes 31 and 32 of the first end plate 30 and the second and second refrigerant discharge holes 41 and 42 of the second end plate 40 are different from each other. It is preferably formed in position.

As in the first embodiment, the refrigerant may flow in the refrigerant inlet holes 31 and 32 and the refrigerant discharge holes 41 and 42 in the first and second end plates 30 and 40. The separate refrigerant pipe 35 is to be connected integrally or separately.

Accordingly, the first refrigerant passage 21 of the internal heat exchanger body 20 may have the same or different types of first and second refrigerants through the refrigerant inlet holes 31 and 32 of the first end plate 30. And flows into the inlets 21a and 22a of the second refrigerant passage 22 and flows mutually while flowing in the refrigerant passages 21 and 22 in a helical direction, and then the second end plate 40 The refrigerant pipe 35 discharged through the outlets 21b and 22b opened by the refrigerant discharge holes 41 and 42 and connected to the refrigerant discharge holes 41 and 42 side of the second end plate 40. It flows into.

FIG. 5 is an exploded perspective view of an internal heat exchanger for carbon dioxide having a double flow channel according to a third embodiment of the present invention.

As shown, the internal heat exchanger body 20 is configured by connecting the plurality of unit heat exchangers (20a, 20b) having the same structure as the internal heat exchanger body 20 of the first embodiment so as to communicate with each other Is installed on one open side of the internal heat exchanger body 20, the first refrigerant and the second refrigerant to the inlet (21a) (22a) side of each of the first refrigerant passage (21) and the second internal medium passage (22) The first end plate 30 having the first and second refrigerant inlet holes 31 and 32 formed therein and the other side of the internal heat exchanger body 20 are installed on the other open side. A second end plate having first and second refrigerant discharge holes 41 and 42 to be discharged through the outlets 21b and 22b of each of the first refrigerant passage 21 and the second refrigerant passage 22; 40 and the first and second connection ports 51 and 52 are formed between the unit heat exchangers 20a and 20b and are different from the refrigerant inlet holes 31 and 32. ,2 It consists of a refrigerant flow conversion member 50 which converts the flow direction of the sheets.

Here, each of the connection ports 51 and 52 of the refrigerant flow converting member 50 is connected to the outlets 21b and 22b of the first and second refrigerant passages 21 and 22 of the unit heat exchanger 20a. The inlet 21a, 22a is connected to the other side unit heat exchanger 20b, so that the inlet 21a, 22a of the first and second refrigerant flow passages 21, 22 of the one side unit heat exchanger 20a is connected. The first and second refrigerants introduced into the side flow through each other while flowing in a helical direction from the outside to the inside, and then open to each of the first and second openings 51 and 52 by the connection ports 51 and 52 of the refrigerant flow converting member 50. 2 are discharged through the outlets 21b and 22b of the refrigerant passages 21 and 22.

Subsequently, the first and second refrigerants passing through the connection ports 51 and 52 are inlets 21a and 22a of the first and second refrigerant passages 21 and 22 of the other unit heat exchanger 20b. The first and second heat exchangers, the first and second refrigerant discharge holes 41 and 42 of the second end plate 40 are exchanged with each other while flowing in a spiral direction from the inner side to the outer side. 2 is discharged through the outlets 21b and 22b of the refrigerant passages 21 and 22 to flow into the refrigerant pipe 35.

Therefore, the refrigerant flow converting member 50, which is a connection passage, is used in the middle of each of the unit heat exchangers 20a and 20b, and the inlet and outlet 21a of each unit heat exchanger 20a and 20b is used. As (21b) (22a) and (22b) are mutually opposite to each other, the heat exchange efficiency can be greatly improved by promoting more turbulence in the internal heat exchanger body (20).

6 is an exploded perspective view illustrating an internal heat exchanger for carbon dioxide having a double flow path according to a fourth embodiment of the present invention, and FIG. 7 is a cross-sectional view illustrating an internal heat exchanger body for carbon dioxide in FIG. 6, which is different from the above embodiment. Only the description will be omitted, and repeated descriptions thereof will be omitted.

As shown in the drawing, a spiral single passage is formed inside the cylinder having both ends open, and the first refrigerant passage 21 through which the first refrigerant flows, and the partition 23 along the first refrigerant passage 21. The first and second refrigerants are formed of a second refrigerant passage 22 formed by a plurality of bridges 24 connecting the partition walls 23 and having a passage so that the second refrigerant flows in a straight line. The internal heat exchanger body 20 and the internal heat exchanger body 20 which are capable of mutual heat exchange as they flow, are installed on one open side of the internal heat exchanger body 20, and the first refrigerant passage and the second refrigerant passage are respectively formed in the first refrigerant passage 21. The first end plate 30 is formed with the first and second refrigerant inlet holes 21 and 22 to be introduced into the inlet 22a side of the second refrigerant passage 22, which is divided into a plurality of inlets 21a and the inlet 21a. ) And the other side of the internal heat exchanger body 20 which is opened, and the first refrigerant passage 21 A first refrigerant discharge hole 41 through which the first refrigerant passed through is discharged is formed, and a second refrigerant discharge hole 42 through which the second refrigerant passed through the second refrigerant passage 22 in a straight line is formed; It is installed on the second end plate 40 and the outside of the first end plate 30, the first and second refrigerant flows into the first and second refrigerant inlet holes 31, 32 to separate the first and second refrigerants 1,2, A first end cap 60 having inlet ports 61 and 62 and a first end cap 60 installed outside the second end plate 40 and discharged from the first and second refrigerant discharge holes 41 and 42; It consists of a second end cap (70) having a first and second discharge ports (71, 72) for dividing the two refrigerant to the outside.

In addition, the first and second end caps 60 and 70 have spaces 63 and 73 in which the refrigerant is temporarily stored.

Here, as in the first embodiment, the first and second refrigerant passages 21 and 22 have first and second refrigerant passages 21a, 21b, 22a having their first and end portions expanded in a substantially circular shape. ) 22b is formed.

In addition, separate refrigerant pipes may flow to each of the inflow ports 61 and 62 of the first end cap 60 and the discharge ports 71 and 72 of the second end cap 70. 35 may be provided integrally or separately.

Therefore, the refrigerant pipe 35 through which the first refrigerant flows passes through the first inlet port 61 of the first end cap 60, and a tip portion thereof enters the first refrigerant of the first end plate 30. As the ball 31 is connected, the first refrigerant flows directly into the inlet 21a of the first refrigerant inlet hole 21 of the internal heat exchanger body 20, and the second refrigerant is the other refrigerant pipe 35. After being introduced into the second inlet port 62 side of the first end cap 60, the first partitioned into a plurality of the first end plate 30 in the state filled with the inner space (63) The second refrigerant inlet hole 32 is introduced into the inlet 22a of the second refrigerant passage 22 divided into a plurality of internal heat exchanger bodies 20.

Subsequently, the first refrigerant flow passage 21 spirally flows in the first refrigerant passage 21 and is opened by the first refrigerant discharge hole 41 of the second end plate 40. Is discharged through the outlet 21b of the c) and flows to the refrigerant pipe 35 connected to the first refrigerant discharge hole 41 of the second end plate 40.

In addition, the second refrigerant is heat-exchanged with the first refrigerant while flowing in the plurality of second refrigerant passages 22 partitioned in a straight line, and is discharged by the second refrigerant discharge holes 42 of the second end plate 40. The refrigerant is discharged through the outlet 22b side of the open second refrigerant passage 22 and flows into the space 73 of the second end cap 70 to be temporarily charged and connected to the second discharge port 72. It flows into the pipe 35.

Therefore, the internal heat exchanger body 20 is further improved in pressure resistance by the bridge 24 formed between the partition walls 23 so that the second refrigerant passage 22 is divided into a plurality of.

As described above, the internal heat exchanger 10 according to the present invention is an internal heat exchanger that mutually heat exchanges a gas cooler outlet refrigerant and an evaporator outlet refrigerant of a carbon dioxide refrigerant system, thereby exchanging high pressure and low pressure on a refrigerating cycle for mutual heat exchange performance. It is to improve.

In addition, when described with reference to the refrigeration cycle as follows.

The refrigerant passes through the compressor, the gas cooler, the expansion valve, and the evaporator in sequence, thereby performing heat exchange with the outside air that is supplied to the cabin.

First, the compressor compresses a gaseous refrigerant into a gaseous state of high temperature and pressure, which is easily liquefied. The refrigerant discharges heat in a supercritical state while passing through a gas cooler, and the first refrigerant of the internal heat exchanger 10 of the present invention. After passing through the flow path 21, the flow to the expansion valve.

Here, the refrigerant is changed into a liquid state while passing through the gas cooler and introduced into the expansion valve.

Subsequently, the refrigerant phase-changed into a liquid state is changed into a low-temperature, low-pressure wet saturated vapor state by the throttling action of the expansion valve, and is introduced into the evaporator, and the refrigerant introduced into the evaporator is heat required for evaporation from the surrounding air (evaporation latent heat). ) Absorbs and evaporates itself, changes to a gaseous state, and then heat exchanges with the refrigerant passing through the first refrigerant passage 21 while passing through the second refrigerant passage 22 of the internal heat exchanger 10 of the present invention. After that, the cycle flowing into the compressor is repeatedly performed.

That is, the refrigerant discharged from the gas cooler is cooled by dissipating heat to the refrigerant discharged from the evaporator, and the refrigerant cooled in the internal heat exchanger 10 of the present invention is in a completely liquid state and is introduced into the expansion valve to expand under reduced pressure.

In addition, the refrigerant evaporated in the evaporator is heated by mutual heat exchange in the internal heat exchanger 10 of the refrigerant discharged from the gas cooler and returned to the compressor.

Therefore, the refrigerant discharged from the gas cooler is supercooled in the internal heat exchanger 10 of the present invention to prevent the malfunction of the expansion valve by preventing the expansion valve from malfunctioning by introducing a refrigerant in a completely liquid state into the expansion valve. .

In addition, even though the evaporator does not evaporate the refrigerant smoothly, even if the dryness of the refrigerant is discharged in a low state, while passing through the internal heat exchanger 10 of the present invention, the heat exchanged with the refrigerant discharged from the gas cooler is heated again to improve dryness. By entering the compressor in a state, it is possible to extend the life of the compressor and at the same time increase the cooling performance and efficiency of the air conditioner.

According to the internal heat exchanger for carbon dioxide according to the present invention, the refrigerant discharged from the gas cooler and the evaporator are formed in the internal heat exchanger body for the carbon dioxide by forming the first and second spiral refrigerant paths opposed to each other with a spiral partition therebetween. The refrigerant discharged from the heat exchange structure passes through each of the refrigerant flow paths, and the refrigerants are in contact with each other through the partition wall to exchange heat, and as the contact surface becomes spiral, the heat exchange area is greatly increased to improve heat exchange efficiency. It will be improved.

In addition, the structure of the internal heat exchanger can be made simple and small in size to reduce the weight and at the same time improve the pressure resistance.

Claims (6)

delete delete delete delete delete The barrier rib is formed between the first refrigerant passage 21 through which the first refrigerant flows and is formed between the partition 23 along the first refrigerant passage 21 in a spiral single passage inside the cylinder having both ends opened. Comprised of a plurality of bridges (24) connecting between the 23 and the second refrigerant flow passage 22 having a passage so that the second refrigerant flows in a straight line consisting of the first and second refrigerant flows as the first and second refrigerants respectively flow Internal heat exchanger body 20 to enable this; First and second refrigerants installed at one open side of the internal heat exchanger body 20 to allow the first and second refrigerants to flow into the first and second refrigerant passages 21 and 22, respectively. A first end plate 30 on which inlet holes 31 and 32 are formed; First and second refrigerant discharge holes 41 installed at the other open side of the internal heat exchanger body 20 and through which the first and second refrigerants passing through the first and second refrigerant passages 21 and 22 are discharged. A second end plate 40 in which 42) is formed; A first and second inlet ports 61 and 62 installed outside the first end plate 30 so as to separately enter the first and second refrigerants into the respective refrigerant inlet holes 31 and 32. End cap 60; And First and second discharge ports 71 and 72, which are installed outside the second end plate 40 to discharge the first and second refrigerants discharged from the respective refrigerant discharge holes 41 and 42 and are discharged to the outside. Internal heat exchanger for carbon dioxide, characterized in that consisting of; a second end cap (70) having.

Images