EP2937658B1 - Internal heat exchanger - Google Patents

Description

Technical area

The invention relates to an internal heat exchanger according to the preamble of the first claim. Such a heat exchanger is known DE 10 2006 017 432 ,

State of the art

Due to legal requirements, the refrigerant R-134a is in future no longer permitted for use in air conditioning systems. As an alternative refrigerant, among other things, R-744 (CO ₂ ) is used as the refrigerant. The refrigerant R-744 is much more environmentally friendly compared to R-134a and still allows for a higher cooling capacity with a comparable volume of the air conditioning system. In addition, a higher efficiency (COP = Coefficient of Performance) is achieved in terms of cooling capacity compared to the compressor performance.

However, this efficiency increase is possible with the use of R-744 as a refrigerant only with the use of an additional heat exchanger, a so-called internal heat exchanger. The refrigerant is further cooled in this inner heat exchanger by heat transfer between the refrigerant on the low pressure side of the refrigerant circuit and the warmer refrigerant on the high pressure side of the refrigerant circuit.

The inner heat exchanger can be integrated as a separate component or designed as a combination element with the so-called accumulator, which acts as a storage device and / or drying device for the refrigerant. The refrigerant on the high pressure side is guided through a line which is arranged on the accumulator and flows around the refrigerant of the low pressure side.

The publication DE 198 30 757 A1 discloses an air conditioner, wherein an internal heat exchanger is provided, which is combined with a condenser and a collector. The inner heat exchanger is arranged in the region of the capacitor, whereby a space-saving solution is generated. The air conditioning system thus produced is particularly suitable for use with the refrigerant R-744 (CO ₂ ).

From the publication DE 60 2005 002 995 T2 Furthermore, a device is known which combines an internal heat exchanger and a rechargeable battery for use in an air conditioning system. The accumulator in this case has an outer wall formed from two hollow-cylindrical shaped elements, which has a plurality of flow channels formed between the hollow cylindrical elements. Through these flow channels, the refrigerant can flow. Thus, a heat transfer can take place between the refrigerant flowing through the flow channels, which are formed in the outer wall, and the refrigerant flowing through the accumulator in the interior.

Furthermore, from the document DE 103 48 141 B3 an internal heat exchanger for high-pressure refrigerant with an accumulator known. The inner heat exchanger is formed by two hollow cylinders arranged one inside the other. In the space between the inner cylinder and the outer cylinder can flow a vapor refrigerant with low pressure. The inner cylinder is designed as a flat tube with a plurality of microchannels, which can be flowed through by a high-pressure refrigerant. In the cavity formed by the inner cylinder, the refrigerant can be further collected with a low pressure. Between the refrigerant with low pressure and the refrigerant with high pressure can be generated by this arrangement, a heat transfer.

From the publication US 2008/0000261 A1 Furthermore, an internal heat exchanger is known, which has an integrated accumulator. The cylindrical accumulator, which can be flowed through by a refrigerant, is surrounded by a tube formed into a helix. Through the pipe can also flow a refrigerant. The tube is arranged between the outer wall of the accumulator and the inner wall of a likewise hollow cylindrical housing. Preferably, a heat transfer between the refrigerant flowing in the pipe and the refrigerant flowing around the pipe can be achieved. The tube is located at the inner heat exchanger or publication US 2008/0000261 A1 both flat on the outer wall of the accumulator and on the inner wall of the housing.

Also from the publication DE 10 2006 031 197 A1 is a heat exchanger with accumulator known, the accumulator is wrapped by a helical tube. The tube and the accumulator are arranged in a hollow cylindrical housing. The helical tube is flat both on the outer wall of the accumulator and on the inner wall of the housing. The tube, the accumulator and the gap between the accumulator and the housing can be flowed through by a refrigerant.

A disadvantage of the solutions of the prior art is in particular that the higher cooling capacity is accompanied by the inner heat exchanger with a higher pressure drop within the refrigerant circuit, which in turn leads to a negative impact on the cooling capacity. In this case, the pressure drop occurs, in particular on the low-pressure side in the region in which the line of the high pressure side is flowed around by the refrigerant of the low pressure side. In addition, the heat transfer between the high-pressure side refrigerant and the low-pressure side refrigerant is not optimal.

From the DE 10 2006 017 432 A1 In addition, a heat exchanger with a calibrated helical finned tube is known. The finned tube is formed into a helix, which comprises an accumulator. The finned tube is formed by a tube which has radially projecting elements. The elements protrude completely circumferentially in the radial direction of the tube from the surface of the tube. As a result, the tube is spaced both in the radial direction of the helix to surrounding structures and the individual turns of the tube in the axial direction of the helix to each other. The spiral-shaped tube and the accumulator can be flowed through by a refrigerant. In particular, a heat transfer between the refrigerant flowing inside the helix and the refrigerant flowing around the helix is generated.

A disadvantage of this solution from the prior art is in particular that a relative movement of the individual turns of the helix to each other in the axial direction of the helix through the elements is not possible. Also, the elements which protrude into the space between the turns impede fluid flow in this area, thereby creating a higher pressure loss. Furthermore, the handling of finned tubes is particularly complex, since they are difficult to process due to the protruding rib elements. The projecting elements can, for example, interlock with each other, which makes assembly difficult.

Presentation of the invention, object, solution, advantages

Therefore, it is the object of the present invention to provide an internal heat exchanger, which allows a heat transfer between the refrigerant of the low pressure side and the refrigerant of the high pressure side, wherein the resulting pressure loss should be minimized. Moreover, the invention relates to an air conditioner with a refrigerant circuit with an internal heat exchanger according to the invention

The object with regard to the internal heat exchanger is achieved by an internal heat exchanger with the features of claim 1.

An embodiment of the invention relates to an internal heat exchanger with a cylindrical accumulator, with a cylindrical housing, with a spiral-shaped tube, with first corrugated fins and second corrugated fins, wherein the accumulator compared to the inner diameter of the housing has a smaller outer diameter and within the Housing is arranged, wherein the helix-shaped tube is disposed in the gap between the accumulator and the housing, wherein the first corrugated fins are arranged in the radial direction between the tube and an outer wall of the accumulator and / or the second corrugated fins in the radial direction between the tube and an inner surface of the housing are arranged.

The arrangement of the corrugated fins in an axial direction inside and outside the helix, an advantageous spacing of the tube relative to the inner walls of the housing and the outer walls of the accumulator can be achieved. The refrigerant flowing through the formed gap can therefore flow through the structure created by the corrugated fins. This causes a much lower pressure loss than the conventional arrangements in which the tube rests directly on the respective inner surfaces and outer surfaces. In such a conventional arrangement, the refrigerant may only run down the individual turns of the coil on the pipe itself, and more particularly in the optional clearances formed between the adjacent turns.

It is particularly advantageous if the free spaces formed in the axial direction between the individual turns of the tube are designed without corrugations. This allows the refrigerant to flow around the individual turns, which promotes the heat exchange.

It is particularly advantageous if the corrugated fins do not fill the free spaces formed between the turns of the helix. Such an arrangement of the corrugated fins is particularly advantageous in order to further reduce the resulting pressure loss.

Alternatively, it is also advantageous if the individual turns of the tube to form contact with each other without open spaces.

It is also advantageous if a plurality of first corrugated ribs and / or in each case a plurality of second corrugated ribs are arranged lined up in the axial direction.

The inner jacket and the outer jacket of the corrugated ribs on the helix can be made in one piece in the axial direction or can be formed from a plurality of hollow cylindrical corrugated rib elements, which are successively pushed onto the helix or pushed into the helix. This is particularly advantageous in terms of mounting. Furthermore, in a simple way, a section-wise adaptation of the corrugated ribs can be carried out by using different corrugated rib elements.

A preferred embodiment is characterized in that the individual turns of the helix are movable in the axial direction relative to each other, wherein in a relative movement in the axial direction, the helix on inner surfaces of the corrugated fins, which face the tube, or the outer surfaces of the corrugated fins, which the Accumulator or the housing, slide on the outer surface of the accumulator or the inner surface of the housing.

By corrugation-free formation of the free spaces between the turns, a relative movement of the turns can take place to each other, which in particular length changes due to thermal fluctuations can be compensated. Depending on whether the corrugated fins are firmly connected to the tube or are loosely arranged on the tube, the tube slides with the corrugated fins on the inner surfaces and outer surfaces of the housing or of the accumulator or on the corrugated fins themselves.

It is also preferable if the corrugated ribs form a first and a third layer in the radial direction, wherein the tube formed into a helix forms a second layer lying between the two layers.

The package of corrugated fins and helix forms a multi-layered in cross-section package. The corrugated ribs thereby form the two outer layers, while the helix is enclosed as a middle layer between the layers of the corrugated ribs. The layers are preferably arranged concentrically to one another. Furthermore, the layers preferably do not protrude into one another in the radial direction but are clearly separated from one another. This is advantageous to produce the corrugated rib-free space between the mutually adjacent turns of the coil. In this way, the pressure loss occurring during the flow is minimized.

Moreover, it is advantageous if the accumulator and the gap between the accumulator and the housing with a refrigerant can be flowed through, wherein the pressure level of the refrigerant in the accumulator and in the gap compared to the pressure level of the refrigerant in the helical shaped tube is smaller. By flowing the gap with the refrigerant from the accumulator, which is associated with the low pressure side of the refrigerant circuit, and the flowing through the coil with the refrigerant, which is associated with the high pressure side of the refrigerant circuit, an additional heat transfer within the refrigerant circuit can be generated, whereby the performance total can be increased.

It is also advantageous if the refrigerant in the accumulator and the refrigerant in the gap to each other in countercurrent and / or in the DC are flowable. By a flow in countercurrent overall a higher heat transfer can be achieved. Depending on the space requirements and the arrangement of the individual elements, however, a flow in the DC can also be provided.

It is also appropriate if the tube has a plurality of fluidically separated flow channels in the interior. Through a tube with several internal flow channels, the heat transfer due to the larger interfaces between the refrigerant in the interior of the tube and the refrigerant flowing around the pipe can be further increased.

Moreover, it is advantageous if the first corrugated ribs and / or the second corrugated ribs are designed as ribs which are V-shaped in cross-section and / or ribs which are trapezoidal in cross section and / or ribs provided with bevels.

Furthermore, it is expedient if the first corrugated ribs and / or second corrugated ribs arranged adjacent to each other in the axial direction have an offset in the circumferential direction relative to each other.

By an offset from each other in the axial direction adjacent corrugated fins in the circumferential direction can be achieved that a plurality of flow channels is formed, which are flowed through by the refrigerant. Due to the deflections of the refrigerant between the individual flow channels, the maximum heat transfer can be further increased.

It is also advantageous if the first corrugated fins and / or the second corrugated fins are permanently connected to the tube formed into a helix. This can be achieved, for example, by the common joining methods of brazing, welding or gluing. A permanent connection is particularly advantageous in terms of mountability.

A further preferred embodiment is characterized in that at the upper end portion of the accumulator, a refrigerant inlet and a refrigerant transfer is arranged, the accumulator can be flowed through in a U-shape, wherein the refrigerant inlet leads from outside the inner heat exchanger through the housing and the gap in the accumulator and a deflection of the refrigerant at the lower end portion of the accumulator is executable, wherein the helical-shaped tube having a first refrigerant port and a second refrigerant port, which pierce the housing to the outside, wherein the housing further comprises a first refrigerant outlet, which from the gap to the outside leads.

Such an arrangement is advantageous in order to ensure a guidance of the refrigerant along the low-pressure side through the inner heat exchanger and at the same time a guidance of the refrigerant on the high-pressure side and furthermore a most effective heat exchange between the refrigerants of the two sides.

The object with respect to the air conditioning is achieved by an air conditioner having the features of claim 12.

An embodiment of the invention relates to an air conditioning system with a refrigerant circuit and an internal heat exchanger, wherein the accumulator is flowable with a refrigerant, which has a lower pressure level compared to the refrigerant in the tube formed into a helix.

An air conditioner with an internal heat exchanger according to the invention is particularly advantageous, since the efficiency of the entire air conditioner can be further increased by, in particular, the cooling capacity can be increased.

Advantageous developments of the present invention are described in the subclaims and in the following description of the figures.

Brief description of the drawings

Fig. 1

einen Querschnitt durch ein zu einer Wendel geformtes Rohr, wobei in radialer Richtung innerhalb der Wendel und außerhalb der Wendel Wellrippen angeordnet sind,

Fig. 2

eine perspektivische Ansicht einer Wendel mit in radialer Richtung innerhalb und außerhalb angeordneten Wellrippen,

Fig. 3

einen Querschnitt durch ein zylindrisches Gehäuse, wobei im Inneren ein zylindrischer Akkumulator angeordnet ist und in dem zwischen dem Gehäuse und dem Akkumulator entstehenden Spalt eine von Wellrippen beidseitig in radialer Richtung umgebene Wendel angeordnet ist,

Fig. 4

einen Querschnitt durch einen inneren Wärmeübertrager, wobei die Durchströmung des Akkumulators, des Spalts und des zu einer Wendel geformten Rohrs dargestellt ist, wobei die Kältemittelströmung im Rohr im Gegenstrom zur Kältemittelströmung im Spalt verläuft,

Fig. 5

einen Querschnitt durch einen inneren Wärmeübertrager gemäß Fig. 4, wobei die Kältemittelströmung im Rohr im Gleichstrom zu der Kältemittelströmung im Spalt verläuft,

Fig. 6

eine perspektivische Ansicht eines zu einer Wendel geformten Rohres,

Fig. 7

alternative Querschnitte für ein Rohr, aus dem die Wendel geformt werden, kann, wobei im oberen Bereich ein ovaler Querschnitt gezeigt ist und im unteren Bereich ein langlochförmiger Querschnitt gezeigt ist,

Fig: 8

zwei unterschiedliche Querschnitte eines Rohres, wobei innehalb der Rohre mehrere einzelne fluidisch voneinander getrennte Strömungskanäle angeordnet sind,

Fig. 9

eine Schnittansicht durch eine wellenförmig ausgeformte Wellrippe, wobei die Wellrippe an ihren Knickstellen eine Kimme aufweist, und

Fig. 10

eine Turbulenzeinlage, welche als Wellrippenersatz zwischen der Wendel und dem Akkumulator beziehungsweise dem Gehäuse angeordnet werden kann.

In the following the invention will be explained in detail by means of embodiments with reference to the drawings. In the drawings show:

Fig. 1

a cross section through a tube formed into a helix, wherein corrugated ribs are arranged in the radial direction within the helix and outside the helix,

Fig. 2

a perspective view of a coil with radially inwardly and outwardly disposed corrugated fins,

Fig. 3

a cross-section through a cylindrical housing, wherein a cylindrical accumulator is arranged in the interior and in the resulting gap between the housing and the accumulator is arranged a corrugated ribs on both sides in the radial direction helix,

Fig. 4

a cross-section through an inner heat exchanger, wherein the flow through the accumulator, the gap and the helical shaped tube is shown, wherein the refrigerant flow in the tube runs in countercurrent to the refrigerant flow in the gap,

Fig. 5

a cross section through an internal heat exchanger according to Fig. 4 wherein the flow of refrigerant in the tube is co-current with the flow of refrigerant in the gap,

Fig. 6

a perspective view of a helix-shaped tube,

Fig. 7

alternative cross-sections for a tube from which the helix can be formed can be seen, wherein an oval cross section is shown in the upper region and a slot-shaped cross section is shown in the lower region,

Fig. 8

two different cross-sections of a tube, wherein a plurality of individual fluidically separate flow channels are arranged inside the tubes,

Fig. 9

a sectional view through a wave-shaped corrugated fin, wherein the corrugated rib at their kinks has a rear sight, and

Fig. 10

a turbulence insert, which can be arranged as a corrugated rib replacement between the coil and the accumulator or the housing.

Preferred embodiment of the invention

The Fig. 1 shows a cross section through a bent into a helix tube 3. The tube 3 has a refrigerant port 4, through which a refrigerant can flow into the tube 3 or can flow out of this.

At the inner periphery of the tube 3 first corrugated fins 2 are arranged. At the outer periphery of the tube 3 second corrugated fins 1 are arranged. The corrugated fins 1, 2 are in each case arranged adjacent to the tube 3 in the radial direction and, in particular, do not engage between the individual turns of the tube 3. The corrugated fins 1, 2 are arranged completely circumferentially on the outer circumference or on the inner circumference of the tube 3. The first corrugated fins 2 thus form an axially extending jacket, which is surrounded by the tube 3, which is shaped as a helix. Furthermore, the second corrugated fins 1 are formed as a jacket, which surrounds the tube 3 on the outer circumference.

The Fig. 2 shows a perspective view of a helix-shaped tube 3 with a refrigerant port 4, as already in Fig. 1 was shown. At least a portion of the tube 3 is surrounded with first corrugated fins 2 on the inner circumference and surrounded with second corrugated fins 1 on the outer circumference. The corrugated fins 1, 2 may extend over the entire axial extent of the helix or be formed of a plurality of subregions, which are successively inserted in the axial direction of the helix or in the helix. The corrugated fins 1, 2 can be pushed onto the helix without further locking or permanently connected thereto by joining methods, such as joining, soldering, welding or gluing.

The tube 3 forms with the corrugated fins 1, 2 a three-layer structure, wherein the middle layer is formed by the tube 3 and both corrugated fins 1, 2 are arranged both on the outer circumference and in the inner circumference. The resulting in the helix free spaces in the axial direction between adjacent turns are not filled in particular by the corrugated fins 1, 2. This is particularly advantageous in terms of mounting, since the corrugated fins can be formed into cylindrical bodies and can be inserted into the coil without great installation effort or can be pushed over the coil. Alternatively, it may also be advantageous if these clearances are not present and touch the windings.

As a tube 3, in particular simple smooth tubes can be used, which are formed in a corresponding shaping process into a helix. In alternative embodiments, special tubes can be used, which will be discussed in the following figures.

The Fig. 3 shows a cross section through an inner heat exchanger 21. This is essentially formed by a cylindrical housing 6, which has mutually parallel outer walls, which form the long side of the housing 6 and two opposite narrow sides, which act as a lid and the housing 6 complete. Inside the housing 6 is an accumulator 7 is arranged, which is also formed cylindrically. The accumulator is used primarily for storing and / or drying and / or filtering a refrigerant which can flow through the accumulator 7. The accumulator 7 has a smaller outer diameter than the inner diameter of the housing 6. In this way arises between the housing 6 and the accumulator 7, a gap 9. Within this gap is in the Fig. 1 and 2 described package, which is formed by the tube 3 and the tube 3 surrounding corrugated fins 1, 2, arranged. The tube 3 is spaced primarily by the first corrugated fins 2 to the accumulator 7 and by the second corrugated fins 1 to the inner surface of the housing. 6

The accumulator 7 is supported via spacer elements 8 in the right region of the figure with respect to an inner surface of the housing 6. In this way, a completely circumferential gap between the accumulator 7 and the housing 6 is generated.

The pipe 3 has a first refrigerant connection 4 and a second refrigerant connection 5. Depending on the direction of flow, the refrigerant connections 4, 5 serve as a fluid inlet or as a Flüidablauf. The helix, which is formed from the tube 3, is in each case completely flowed through by the refrigerant.

For mounting the accumulator 7 of the corrugated fins 1, 2 and the tube 3, preferably, an end portion of the housing 6 can be separated to realize a insertion opening.

The Fig. 4 shows a further sectional view through the inner heat exchanger 21. In addition to Fig. 3 the inner heat exchanger 21 has a refrigerant inlet 10 at the left end region, via which a refrigerant can flow through the housing 6 into the accumulator 7 along the flow direction 12. There, the refrigerant in the right area of the Fig. 4 flow and are deflected along the arrow 13, before it flows back to the left end of the accumulator 7 again. Along the flow direction 14, an overflow region is shown, through which the refrigerant from the accumulator 7 can flow into the gap 9 between the housing 6 and the accumulator 7. The refrigerant can flow along the entire circumference in the gap 9 and from left to right, the tube 3 and the corrugated fins 1, 2 flow around.

In a final mounted position is in the Fig. 3 to 5 each area shown on the right side directed down and arranged the left end of each directed upward.

Through the pipe 3, in particular, the refrigerant flows at a pressure which is higher than the pressure of the refrigerant, which flows through the accumulator 7 and the gap 9. At the right end portion of the housing 6, a refrigerant outlet 11 is further arranged, via which the refrigerant can flow out of the housing 6 after the flow through the gap 9. The pipe 3 is supplied along the flow direction 17 through the refrigerant port 5 with a refrigerant. Via the refrigerant connection 4, the refrigerant can flow out of the tube 3 in the direction of the flow arrow 18.

In Fig. 4 a flow through the inner heat exchanger is shown, wherein the refrigerant flows in the pipe 3 in a counterflow to the refrigerant in the gap 9. This is particularly advantageous in order to realize a higher heat transfer.

The Fig. 5 shows a sectional view through an internal heat exchanger 21 analogous to Fig. 4 , The reference numerals therefore come, as far as the same elements are designated, match. In contrast to Fig. 4 the refrigerant of the higher pressure, which flows through the pipe 3, flows into the pipe 3 along the left-hand fluid connection 4 along the flow arrow 19. The refrigerant finally flows out along the flow arrow 20 from the refrigerant connector 5 at the right end region. The flow through the accumulator 7 and the gap 9 has not changed thereby. As a result, the tube 3 and the gap 9 are flowed through in direct current.

The Fig. 6 shows a perspective view of a coil, which is formed from the circularly wound tube 3, which further comprises the refrigerant port 4 at the left end portion and the refrigerant port 5 at the right end portion.

The Fig. 7 shows by the reference numeral 30, an alternative cross-sectional shape for the tube 3. The reference numeral 30 in particular an oval or elliptical cross-sectional shape of the tube 3 is shown. By the reference numeral 31, a slot-like cross-sectional shape is shown, which is formed essentially of two mutually parallel broad sides, which are completed by rounded semicircular narrow sides to a closed pipe contour.

The Fig. 8 shows two cross sections of flat tubes 32, 34. The flat tube 32 has in its interior a plurality of circular cross-sectional flow channels 33, which are arranged in a row adjacent to each other. The flat tube 34, which is arranged underneath, has an alternative embodiment, in which a plurality of flow channels 35, which have a square cross section, are arranged in a row next to one another.

The flat tubes 32, 34 may also form the base material for forming the helix, which is arranged in the gap 9 of the inner heat exchanger 21. In particular, the number of flow channels 33, 35 in the flat tubes 32, 34 of the in Fig. 8 differ from the example shown.

The Fig. 9 shows a sectional view through a corrugated fin 36, wherein the rib elements are each arranged W-shaped, in particular, the kink of the corrugated fins, which are arranged in the upper end region or in the lower end of the corrugated fins 36, provided with a Komme 37. In the area of the rear sight 37, in particular, the material of the corrugated rib is pressed against one another.

The Fig. 10 shows a turbulence insert 38, which can be used as an alternative to the corrugated fins 1 and 2. The turbulence insert 38 in this case has first flow channels 39, 40 and 41, which are also found in the right adjacent elements of the turbulence insert 38 each. The flow channels 39, 40 and 41 are formed in particular by an offset of the sections 42 and 43 of the turbulence insert to each other. In this case, the turbulence insert 38 can be produced in particular by a partial deflection of partial regions from one plane only. For this purpose, various methods for producing a corresponding turbulence insert are known in the prior art.

The in the Fig. 1 to 10 Embodiments shown are merely exemplary and serve to illustrate the inventive concept. In particular, with regard to the design, the choice of materials and the arrangement of the individual elements to each other have the Fig. 1 to 10 no limiting character.

It is essential for the invention that the tube formed into a helix is surrounded both on the outer circumference and on the inner periphery by a sheath-like corrugated rib structure, whereby the tube can be spaced to inner surfaces or outer surfaces of the housing or the accumulator.

The gap generated by the corrugated fins between the tube 3 and the inner walls or outer walls of the housing 6 and the accumulator 7 is preferably flowed through by the refrigerant, whereby in particular a lower pressure drop is generated than in the known in the prior art solutions which no spacing of Provide pipe to the inner wall of the housing or to the outer wall of the accumulator.

Claims (14)

1. An internal heat exchanger (21) with a cylindrical accumulator (7), with a cylindrical housing (6), with a tube (3) shaped into a coil, with first corrugated fins (2) and with second corrugated fins (1), wherein the accumulator (7) has a smaller outer diameter compared to the inner diameter of the housing (6) and is arranged within the housing (6), wherein the tube (3) shaped into a coil is arranged in the gap (9) between the accumulator (7) and the housing (6), characterised in that the first corrugated fins (2) are arranged in the radial direction between the tube (3) and an outer wall of the accumulator (7) and/or the second corrugated fins (1) are arranged in the radial direction between the tube (3) and an inner surface of the housing (6).
2. The internal heat exchanger according to claim 1, characterised in that the clearances formed in the axial direction between the individual windings of the tube (3) are constructed free from corrugated fins.
3. The internal heat exchanger according to claim 1, characterised in that the individual windings of the tube touch each other without forming clearances.
4. The internal heat exchanger (21) according to claim 1, 2 or 3, characterised in that a plurality of first corrugated fins (2) and/or a plurality of second corrugated fins (1) is in each case arranged in a row in the axial direction.
5. The internal heat exchanger (21) according to one of the preceding claims, characterised in that the individual windings of the coil are movable relative to each other in the axial direction, wherein during a relative movement in the axial direction, the windings on inner surfaces of the corrugated fins (1, 2) which face the tube (3) slide or the outer surfaces of the corrugated fins (1, 2) which face the accumulator (7) or the housing (6) slide on the outer surface of the accumulator (7) or the inner surface of the housing (6).
6. The internal heat exchanger (21) according to one of the preceding claims, characterised in that the corrugated fins (1, 2) form a first and a third layer in the radial direction, wherein the tube (3) shaped into a coil forms a second layer lying between the two layers.
7. The internal heat exchanger (21) according to one of the preceding claims, characterised in that the accumulator (7) and the gap (9) between the accumulator (7) and the housing (6) can be flowed through by a refrigerant, wherein the pressure level of the refrigerant in the accumulator (7) and in the gap (9) is less compared to the pressure level of the refrigerant in the tube (3) shaped into a coil.
8. The internal heat exchanger (21) according to one of the preceding claims, characterised in that the refrigerant in the accumulator (7) and the refrigerant in the gap (9) can flow towards each other in counter flow and/or in co-flow.
9. The internal heat exchanger (21) according to one of the preceding claims, characterised in that the tube (32, 34) has a plurality of flow channels (33, 35) on the inside which are fluidly separated from each other.
10. The internal heat exchanger (21) according to one of the preceding claims, characterised in that the first corrugated fins (2) and/or the second corrugated fins (1) are formed as fins which are V-shaped in the cross-section and/or as fins which are trapezoidal in the cross-section and/or as fins provided with chines.
11. The internal heat exchanger (21) according to one of the preceding claims, characterised in that the first corrugated fins (2) and/or second corrugated fins (1) which are respectively arranged adjacent to each other in the axial direction have an offset in the circumferential direction relative to each other.
12. The internal heat exchanger (21) according to one of the preceding claims, characterised in that the first corrugated fins (2) and/or the second corrugated fins (1) are permanently connected to the tube (3) shaped into a coil.
13. The internal heat exchanger (21) according to one of the preceding claims, characterised in that a refrigerant inlet (10) and a refrigerant transfer are arranged in the upper end portion of the accumulator (7), wherein the accumulator (7) can be flowed through in a U-shape, wherein the refrigerant inlet (10) leads from outside the internal heat exchanger (21) through the housing (6) and the gap (9) into the accumulator (7) and a deflection (13) of the refrigerant can be performed in the lower end portion of the accumulator (7), wherein the tube (3) shaped into a coil has a first refrigerant port (4) and a second refrigerant port (5) which penetrate the housing (6) to the outside, wherein the housing (6) further has a first refrigerant outlet (11) which leads to the outside from the gap (9).
14. An air-conditioning system having a refrigerant circuit and an internal heat exchanger (21) according to one of the preceding claims, characterised in that the accumulator (7) can be flowed through by a refrigerant which in comparison to the refrigerant in the tube (3) shaped into a coil has a lower pressure level.

Images