DE102016201395A1 - Method for producing a heat exchanger device - Google Patents

Abstract

The invention relates to a method for producing a heat exchanger device (10) for a refrigeration system, in particular for a refrigeration system which works with CO.sub.2, having a housing (22) in which a high-pressure channel (18) and a low-pressure channel (20) for a refrigerant ( 12), with a heat exchanger (26) fluidly separating and thermally coupling the high pressure channel (18) and the low pressure channel (20), and a refrigerant receiver (28) disposed in the low pressure channel (20) between the housing (22) and the heat exchanger (26) an outer annular space (38) is formed, wherein between the heat exchanger (26) and the refrigerant collecting container (28) an inner annular space (68) is formed. In order to improve the quality of the component is proposed that for the production of the housing (22), the heat exchanger (26) and / or the refrigerant collecting container (28), a material is set by heating in a thixotropic state that as a material aluminum or an aluminum alloy is used, and that the material is passed in the thixotropic state in a negative mold.

Description

The invention relates to a method for producing a heat exchanger device for a refrigeration system, according to the preamble of claim 1. Furthermore, the invention relates to a refrigeration system with a heat exchanger device, which is produced by such a method and a motor vehicle with such a refrigeration system.

Such heat exchanger devices are used in refrigeration systems, in particular in refrigeration systems of an air conditioning system, for example a vehicle air conditioning system. By using these heat exchanger devices, the efficiency of the refrigeration system, in particular when using CO ₂ (R744) as a refrigerant, can be improved. By means of the heat exchanger device, the low temperature level of the low pressure region of the refrigeration circuit can be used to further cool the warmer refrigerant in the high pressure region immediately after the gas cooler. In this case, the heat exchanger device can be combined with a refrigerant collecting container (accumulator).

When using CO ₂ as the refrigerant, relatively high pressures prevail in the refrigeration cycle. Therefore, the production of the heat exchanger device, in particular the housing, the heat exchanger and the refrigerant collecting container is complicated. In conventional casting processes, such as aluminum die-casting process, defects, so-called voids and pores, occur in the component. As a result, the strength of the component is reduced. In pressure vessels would therefore have to be worked with a large wall thickness. The use of forged or reworked housing parts is considerably more expensive and expensive.

The object of the invention is to provide an improved or at least other embodiment of a method for producing a heat exchanger device, which is characterized in particular by lower production costs and a higher component quality.

This object is achieved by the subjects of the independent claims. Advantageous developments are the subject of the dependent claims.

The invention is based on the general idea of specifying a shaping method for producing the housing, the heat exchanger and / or the refrigerant collecting container, which allows the formation of complex and fine structures and at the same time allows a high component quality or small defects in the component. According to the invention it is provided that for the production of the housing, the heat exchanger and / or the refrigerant collecting a material is caused by heating in a thixotropic state that is used as a material aluminum or an aluminum alloy and that the material is passed in the thixotropic state in a negative mold. In the thixotropic state is a mixed phase of solid and liquid phases of the material, the solid phases are small and finely divided and are surrounded by a continuous liquid phase. A thixotropic state is characterized by the fact that the viscosity is reduced by the introduction of mechanical energy, in particular by shear stresses. When introducing the material in the thixotropic state in the negative mold turbulence can be prevented so that air pockets can be prevented in the material. As a result, on the one hand a very high component quality and thus high strength of the component can be achieved. On the other hand, very fine and filigree details can be formed on the component in this way.

In the description and the appended claims, the terms high pressure and low pressure relate to each other, that is to say that a higher pressure prevails in operation in the high pressure range than in the low pressure range. Typical pressures in the high pressure range are about 15 MPa. Typical pressures in the low pressure range are about 10 MPa.

Alternatively or additionally, it can be provided that plastic is used as the material for the refrigerant collecting container and that the refrigerant collecting container is produced by plastic injection molding.

A favorable possibility provides that the material is passed laminar into the negative mold. Due to the laminar introduction of the material into the negative mold, no vortices occur which could introduce air into the material and could thus lead to defects, pores or voids. Consequently, the quality of the component is thereby increased.

Another favorable possibility provides that on an outer side of the heat exchanger ribs are formed, which protrude into the outer annulus. These ribs are already formed in the negative mold, so that the part of the heat transfer thus formed requires only a few post-processing steps.

Another particularly favorable possibility provides that the heat exchanger is arranged in the housing such that the ribs on the outside of the heat exchanger extend to the housing. Thereby, the radial rib length can be increased, whereby the surface of the heat exchanger on the outside is enlarged. Consequently, thus, the heat coupling to the refrigerant in the outer annulus can be improved.

An advantageous solution provides that ribs are formed on an inner side of the heat exchanger, which protrude into the inner annular space. This increases the heat transfer area to the refrigerant in the low pressure channel. Preferably, the ribs are already provided in the negative form of the heat exchanger, so that no finishing step is necessary for the ribs.

A particularly advantageous solution provides that the refrigerant collecting container is arranged in the heat exchanger such that the ribs on the inside of the heat exchanger extend as far as the refrigerant collecting container. As a result, the radial rib length is increased, so that the heat transfer surface on the inside of the heat exchanger is further increased. Furthermore, thereby the inner annulus between the refrigerant receiver and the heat exchanger is divided into a plurality of channels, whereby the heat transfer to the refrigerant is also improved.

Another particularly advantageous solution provides that a wall thickness of the heat exchanger is between 0.5 mm and 2 mm. Such a wall thickness can be produced by the method according to the invention. Due to the high strength of the heat exchanger thus produced such a wall thickness is sufficient to withstand the pressures of the refrigerant. At the same time, the relatively small wall thickness leads to a high heat transfer between the low-pressure channel and the high-pressure channel.

A favorable variant provides that two identical parts of the heat exchanger are produced, and that the common parts of the heat exchanger are connected to each other. In this way, the same negative mold can be used for both identical parts to produce the heat exchanger from the two identical parts. To produce a largely closed hollow body is necessary in a casting process to divide the component into two parts, since otherwise the component can not be removed from the negative mold. Nevertheless, the formation of two identical parts can considerably reduce the production outlay since the same negative mold can be used for both identical parts.

A further favorable variant provides that ribs are formed on an outer side of the refrigerant collecting container which protrude into the inner annular space. Thereby, the heat transfer from the refrigerant tank to the coolant in the inner annulus is improved. Preferably, the ribs are already provided in the negative mold, so that no finishing steps are necessary for the ribs.

A particularly favorable variant provides that the refrigerant collecting container is arranged in the heat exchanger such that the ribs on the outside of the refrigerant collecting container extend to the heat exchanger. Thereby, the inner annular space between the refrigerant receiver and the heat exchanger is divided into a plurality of channels, whereby the heat transfer to the refrigerant is also improved.

Another particularly favorable variant provides that two identical parts of the refrigerant collecting container are produced, and that the common parts of the refrigerant collecting container are connected to each other. In this way only one negative mold is needed to make the refrigerant receiver.

Preferably, the two identical parts of the refrigerant collecting container are welded together. Thereby, a fluid density and stable connection between the two identical parts can be produced.

An advantageous possibility provides that ribs are formed on an inner side of the housing, which protrude into the outer annular space. This improves the stiffness of the case, reducing wall thickness and saving material. Moreover, the fins in the outer annulus create turbulence in the refrigerant, so that the heat transfer between the refrigerant and the heat exchanger is improved.

Preferably, the ribs are already provided in the negative mold of the housing, so that no further post-processing step is necessary for the ribs.

A further advantageous possibility provides that the heat exchanger is arranged in the housing such that the ribs rest against the heat exchanger on the inside of the housing. In this way, the heat exchanger can be supported radially outward on the housing, so that the wall thickness of the heat exchanger can be further reduced.

A particularly advantageous possibility provides that two identical parts of the housing are produced, and that the common parts of the housing are connected to each other. This can help with the Production of the housing to be used a mold. Preferably, the two common parts of the housing are welded together to form the housing.

A favorable solution provides that a grid structure is formed on an outer side of the housing. Preferably, the grid structure is already formed in the negative mold of the housing, so that no post-processing steps are necessary to form the grid structure. The grid structure on the outside increases the pressure stability of the housing.

Another favorable solution provides that the grid structure on the outside of the housing forms a triangular or quadrilateral grid, so-called isogrid or ortho-grid structures. Such grids are regular structures that are easy to design and increase stability.

A particularly favorable solution provides that the housing, the heat exchanger and the refrigerant collecting container are arranged such that the respective mutually facing ribs engage with each other. In this way, a space-saving arrangement can be found in which an excellent increase of the heat transfer area can be achieved.

Another particularly favorable solution provides that the inner annular space at least partially forms the low-pressure channel. As a result, the coolant which flows through the low-pressure channel must also flow through the inner annular space and can thereby absorb heat from the heat exchanger.

An advantageous variant provides that the outer annular space at least partially forms the high-pressure channel. As a result, the coolant that flows through the high-pressure channel must also flow through the outer annular space and thus can deliver heat to the heat exchanger.

A further advantageous variant provides that a desiccant is arranged in the high-pressure passage in the region of the high-pressure inlet. This allows water contained in the refrigerant to be collected. By achieved by the method, high strength of the material, the wall thicknesses of the housing and the heat exchanger can be reduced, so that the outer and inner annulus can be increased. Therefore, it is possible to arrange a desiccant in the outer annulus. Accordingly, a desiccant can also be arranged in the low-pressure channel in the region of the low-pressure outlet.

Further, the invention is based on the general idea to use a refrigeration system for CO ₂ with a refrigerant circuit in which circulates refrigerant in operation, with a compressor for driving the refrigerant, with an expansion valve, which separates a high pressure region and a low pressure region of the refrigerant circuit from each other a gas cooler for cooling the refrigerant in the high-pressure region, with an evaporator, with a heat exchanger device, which is produced by a method as described above, wherein the high-pressure passage of the heat exchanger device is connected in the high-pressure region of the refrigerant circuit downstream of the gas cooler and upstream of the expansion valve, and wherein the low-pressure channel of the heat exchanger device is arranged in the low-pressure region of the refrigerant circuit downstream of the expansion valve. As a result, the advantages of the manufacturing method of the heat exchanger device can be optimally utilized, the above description of which reference is made in this regard.

Furthermore, it is favorable if the heat exchanger device is connected in the refrigerant circuit such that the high-pressure channel and the low-pressure channel are flowed through in countercurrent or cross-flow or a mixed form thereof. As a result, the heat between two media can be optimally replaced.

Moreover, it is advantageous if the refrigerant is CO ₂ . Conventional refrigerants are often harmful to the environment. For a long time CFC-containing refrigerants have been banned, which attack the ozone hole. However, the replacement refrigerants used are very strong in terms of climate. That means they have a very high greenhouse gas coefficient. Although CO ₂ is also greenhouse active, but significantly lower than the previously used refrigerant.

Moreover, the invention is based on the general idea to use a refrigeration system as described above in a motor vehicle. The advantages of the refrigeration system are thus transferred to the motor vehicle to the above description insofar reference is made.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained not only in the combination given, but also in other combinations or alone, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Show, in each case schematically,

1 a sectional view along a longitudinal section through a heat exchanger device according to the invention,

2 a longitudinal sectional view through a first variant of a common part of the housing,

3 a longitudinal sectional view through a second variant of a common part of the housing,

4 a section of a sectional view along the cutting plane AA 1 in a first variant of the rib arrangement,

5 one of the 4 corresponding sectional view according to a second variant of the rib arrangement,

6 one of the 4 corresponding sectional view of a third variant of the rib arrangement,

7 one of the 4 corresponding sectional view of a fourth variant of the rib arrangement,

8th a longitudinal sectional view through a low-pressure inlet adapter, in a first variant,

9 a longitudinal sectional view through a low-pressure inlet adapter of a second variant, in which a filter element is provided,

10 a longitudinal sectional view through a low-pressure outlet adapter of a first variant,

11 a longitudinal sectional view through a Niederdruckauslassadapter according to a second variant, in which a filter element is arranged on the Niederdruckauslassadapter,

12 a sectional view of a Ölaustragseinrichtung according to a second embodiment,

13 a sectional view through an oil discharge device according to a third embodiment, and

14 a sectional view through an oil discharge device according to a fourth embodiment.

One in the 1 to 11 illustrated first embodiment of a heat exchanger device 10 is used in air conditioning systems for motor vehicles, in particular CO ₂ as a refrigerant 12 use. The heat exchanger device 10 includes a refrigerant receiver 28 and a heat exchanger 26 , The heat exchanger device 10 is usually installed in a refrigerant circuit of the refrigeration system, a typical order being as follows. From the compressor, the refrigerant is sent to a gas cooler, where it can give off heat to the environment, on to an internal heat exchanger 16 at least partially through the heat exchanger 26 is formed and to which the refrigerant 12 can still give off more heat. In particular, the refrigerant flows 12 through a high pressure channel 18 the heat exchanger device 10 , From the heat exchanger device 10 off is the refrigerant 12 to an expansion valve, which separates a high-pressure area of the refrigerant circuit from a low-pressure area of the refrigerant circuit. Behind the expansion valve, the refrigerant can 12 expand and thereby cool. After the expansion valve becomes the refrigerant 12 again to the heat exchanger device 10 , in particular to the inner heat exchanger 16 in a low pressure channel 20 passed, in which the refrigerant heat from the high-pressure channel 18 can record. From there is the refrigerant 12 directed to a heat exchanger which serves to absorb heat from an object or component or medium to be cooled. From this heat exchanger becomes the refrigerant 12 returned to the compressor, which is the refrigerant 12 drives and thus closes the cycle.

Through the inner heat exchanger 16 becomes the refrigerant 12 at the expansion valve brought to a lower temperature level. When using CO ₂ as a refrigerant 12 This can improve the efficiency of the refrigeration system.

The heat exchanger device 10 has a housing 22 on, that has an interior 24 encloses. In the interior 24 are the heat exchanger 26 and the refrigerant receiver 28 arranged.

At a first axial end 30 are a low pressure opening 32 and a high pressure port 34 arranged. The low pressure opening 32 is preferably coaxial with a longitudinal central axis 36 the heat exchanger device 10 arranged. The High pressure port 34 is preferably eccentric to the longitudinal central axis 36 arranged.

The low pressure opening 32 provides a fluid connection to the low pressure channel 20 , Accordingly, the high-pressure opening offers 34 a fluid connection to the high pressure passage 18 , The low pressure channel 20 and the high pressure channel 18 are heat coupled and media separated formed. The heat coupling and the media separation are through the heat exchanger 26 causes. Thus form the high-pressure channel 18 , the low pressure channel 20 and the heat exchanger 26 the inner heat exchanger 16 ,

Between the heat exchanger 26 and the housing 22 is an outer annulus 38 educated. There is fluid communication from the outer annulus 38 to the high-pressure opening 34 , Thus, the outer annulus forms 38 at least part of the high pressure channel 18 , On an exterior wall 40 of the housing 22 can ribs 42 be provided. It can ribs 42 on an outside 44 be arranged and the stability of the housing 22 increase. For example, the ribs 42 on the outside 44 the outer wall 40 be arranged in the form of a grid, for example. A triangular grid or a quadrangular grid.

Furthermore, ribs can 42 on an inside 46 the outer wall 40 be arranged, which also improve the stability of the housing. In addition, the ribs can 42 in the outer annulus 38 Turbulence in the refrigerant 12 induce, so that the heat transfer between the refrigerant 12 and the heat exchanger 26 is improved.

The housing 22 preferably has two identical parts 48 on. The identical parts 48 have a slightly conical shape so that they can be produced by a casting method or by a manufacturing method similar to a casting method. In particular, the common parts 48 be prepared by the material is introduced into a negative mold. Due to the slightly conical shape, the identical parts 48 simply removed from the negative mold.

The identical parts 48 are connected together to the housing 22 to form and thus the interior 24 to enclose.

The connection of the common parts 48 In this case, for example, it can be produced by positive locking, material connection or frictional connection, particularly preferably by welding or screwing. Both identical parts 48 each have one of the low pressure openings 32 and one of the high pressure ports 34 on.

Due to the design of the housing 22 from two identical parts 48 the manufacturing costs are reduced, as by an identical negative mold both for the production of the housing 22 needed equal parts 48 can be produced.

At a second axial end 50 shows the case 22 also a low pressure opening 32 and a high pressure port 34 on. Also in the second axial end 50 is the low pressure opening 32 Preferably arranged coaxially and the high-pressure opening 34 preferably arranged eccentrically. This can be one of the same parts 48 the first axial end 30 and the other equal part 48 the second axial end 50 of the housing 22 form.

In the 2 and 3 are two variants of the same parts 48 of the housing 22 shown. At the in 2 variant shown are connections 51 for the low-pressure opening 32 and the high pressure port 34 directed axially. At the in 3 variant shown are the connections 51 directed radially. Other oblique alignments of the connections 51 are also possible. As a result, the heat exchanger device 10 be adapted to different arrangements of the refrigeration system.

In the interior 24 of the housing 22 is the heat exchanger 26 arranged and in turn encloses an interior 52 of the heat exchanger 26 , In the interior 52 of the heat exchanger 26 is the refrigerant tank 28 arranged.

The heat exchanger 26 has at a first axial end 54 of the heat exchanger 26 an inlet nozzle 56 on which an opening to the interior 52 forms. Furthermore, the inlet nozzle engages 56 into one of the low-pressure openings 32 of the housing 22 , As a result, the inlet nozzle forms a fluid connection from the interior 52 of the heat exchanger 26 outward.

Furthermore, the heat exchanger points 26 at a second axial end 58 an outlet 60 on which an opening in the interior 52 of the heat exchanger 26 forms. The outlet nozzle 60 reaches into one of the low-pressure openings 32 of the housing 22 a, preferably in the low-pressure opening 32 at the second axial end 50 of the housing 22 , Thus forms the outlet 60 a fluid connection from the interior 52 of the heat exchanger 26 outward.

An outer wall 62 limited with an outside 64 the outer wall 62 the outer annulus 38 inside. With an inside 66 limits the outer wall 62 an inner annulus 68 outward. The inner annulus 68 is between the heat exchanger 26 and the Refrigerant collecting 28 educated. The inner annulus 68 at least partially forms the low pressure channel 20 ,

On the outside 64 the outer wall 62 can ribs 42 be provided in the outer annulus 38 protrude. This allows the heat transfer between the refrigerant 12 in the outer annulus 38 and the heat exchanger 26 be improved.

Furthermore, on the inside 66 the outer wall 62 ribs 42 be provided, which in the inner annulus 68 grab the heat transfer between the refrigerant 12 in the inner annulus 68 and the heat exchanger 26 to improve.

Also the heat exchanger 26 preferably has two identical parts 70 on, which are interconnected. At a first of the same parts 70 is the inlet nozzle 56 formed and at a second of the same parts 70 of the heat exchanger 26 is the outlet nozzle 60 formed, which are geometrically equal in itself. The connection of the common parts 70 of the heat exchanger 26 to the heat exchanger 26 can be done by positive engagement, material connection or frictional engagement. Particularly preferred are the identical parts 70 welded or bolted together.

Between the heat exchanger 26 and the housing 22 are several, for example four, sealing elements 71 intended. At the first axial end 54 is one of the sealing elements 71 arranged. It lies in one at the corresponding low-pressure opening 32 of the housing 22 formed groove and thus seals the inlet nozzle 56 against the low pressure opening 32 from. Thus, the outer annulus 38 and thus the high-pressure channel 18 against the low pressure opening 32 sealed. Accordingly, at the second axial end 58 of the heat exchanger 26 one of the sealing elements 71 arranged.

Furthermore, in the region of a connection point of the respective identical parts 48 and 70 of the housing 22 and the heat exchanger 26 such sealing elements 71 arranged. The identical parts 70 of the heat exchanger 26 each have a circumferential collar at the junction 73 on, to the respective axial end 54 . 58 form directed sealing surfaces. Each of these sealing surfaces is one of the annular sealing elements 71 at.

In the same parts 48 of the housing 22 a recess is arranged at the connection point, on which an axial sealing surface 75 is formed on which one of the sealing elements 71 is applied. Thus, by the sealing elements 71 at the junction an additional seal of the high pressure channel 18 formed against the environment.

In the surrounding collar 73 are several through holes 77 formed, which in the axial direction, the outer annular spaces 38 , each in one half of the heat exchanger device 10 are formed, connect with each other.

In the interior 52 of the heat exchanger 26 is the refrigerant tank 28 arranged and in turn encloses an interior 72 , which is a refrigerant collection area 74 forms.

At a first axial end 76 of the refrigerant tank 28 are at least one, preferably two inlet holes 78 arranged, which are eccentric to the longitudinal central axis 36 the heat exchanger device 10 are arranged. The inlet holes 78 thus form a refrigerant inlet 79 of the refrigerant tank 28 , Furthermore, the refrigerant receiver 28 at the first axial end 76 an outlet hole 80 which is preferably coaxial with the longitudinal central axis 36 is arranged.

To refrigerant that through a low-pressure opening 32 at the first axial end 30 of the housing 22 flows directly into the refrigerant collecting area 74 of the refrigerant tank 28 To be able to conduct is a low pressure inlet adapter 82 intended. The low pressure inlet adapter 82 provides fluid communication from the low pressure port 32 at the first axial end 30 in the interior 72 and thus into the refrigerant collecting area 74 of the refrigerant tank 28 ,

The low pressure inlet adapter 82 engages in at least one inlet bore 78 a, allowing a fluid connection in the interior 72 of the refrigerant tank 28 can be achieved. Furthermore, the low-pressure inlet adapter engages 82 in the inlet pipe 56 of the heat exchanger 26 a, so that the fluid connection to the low-pressure opening 32 of the housing 22 is made.

At a second axial end 84 is the refrigerant tank 28 closed trained. In particular, at the second axial end 84 a floor 86 formed, on which refrigerant in solid and / or liquid form can accumulate.

At the second axial end 84 , outside the refrigerant receiver 28 , is a low pressure outlet adapter 88 arranged. The low pressure outlet adapter 88 So is between the refrigerant tank 28 and the heat exchanger 26 arranged. Preferably, the low pressure outlet adapter engages 88 in the outlet 60 of the heat exchanger 26 and thus provides a fluid connection to the low-pressure opening 32 at the second axial end 50 of the housing 22 , Furthermore, the offers Niederdruckauslassadapter 88 a fluid connection to the inner annulus 68 ,

Thus, the low pressure channel 20 between the two low-pressure openings 32 of the housing 22 educated. The low pressure channel 20 extends from the low pressure port 32 at the first axial end 76 into the refrigerant tank 28 in and at the first axial end 76 again from the refrigerant tank 28 out into the inner annulus 68 into it. Next extends the low pressure channel 20 along the inner annulus 68 to the second axial end 84 of the refrigerant tank 28 and there through the low pressure outlet adapter 88 and through the outlet 60 of the heat exchanger 26 ,

Also the refrigerant tank 28 has two equal parts 90 on, which are interconnected. The two identical parts 90 of the refrigerant tank 28 differ through the inlet hole 78 and the outlet hole 80 at the first axial end 76 of the refrigerant tank 28 from each other. Nevertheless, the two identical parts 90 be made by a common negative mold. Only small post-processing steps, namely the drilling of the inlet bore 78 and the outlet hole 80 are necessary to the common parts 90 adapt.

The low pressure inlet adapter 82 and the low pressure outlet adapter 88 cause the required asymmetry for the flow guidance. So can the case 22 , the heat exchanger 26 and the refrigerant receiver 28 from the same parts 48 . 70 and 90 be prepared.

On an outside 92 can the refrigerant tank 28 ribs 42 that are in the inner annulus 68 to grab. As a result, on the one hand, the stability of the refrigerant collecting container 28 be improved. For another, through the ribs 42 Turbulence in the refrigerant in the inner annulus 68 which also improves heat transfer to the heat exchanger 26 enable. This is the heat transfer between the refrigerant 12 in the low pressure channel 20 and the refrigerant 12 in the high pressure channel 18 improved.

In the 4 to 7 are four different exemplary variants for the arrangement of the ribs 42 on the housing 22 , on the heat exchanger 26 and the refrigerant receiver 28 shown. At the in 4 illustrated variant are on the outer wall 40 of the housing 22 both on the outside 44 as well as on the inside 46 ribs 42 arranged. Also on the outside wall 62 of the heat exchanger 26 both on the outside 64 as well as on the inside 66 ribs 42 arranged. Also on the refrigerant tank 28 are ribs on the outside 42 arranged. The refrigerant receiver 28 , the heat exchanger 26 and the case 22 are arranged such that the ribs 42 mesh.

At the in 5 illustrated variant are on the outside 44 the outer wall 40 of the housing 22 no ribs arranged. Likewise are on the outside 92 of the refrigerant tank 28 no ribs 42 arranged. The at the heat exchanger 26 arranged ribs and the housing 22 arranged ribs 42 extend as far into the respective annulus 38 . 68 that they touch the opposite wall.

The on the outside wall 40 of the housing 22 arranged ribs 42 protrude into the outer annulus 38 in and touch the outside 64 of the heat exchanger 26 , The on the outside 64 of the heat exchanger 26 arranged ribs 42 protrude into the outer annulus 38 and touch the inside 46 of the housing 22 , The on the inside 66 the outer wall 62 of the heat exchanger 26 arranged ribs 42 protrude into the inner annulus 68 in and touch the outside 92 of the refrigerant tank 28 ,

At the in 6 variant shown are only ribs 42 provided in the outer annulus 38 protrude. There are both the heat exchanger and the housing 22 two different varieties of ribs provided. A first variety extends through the entire outer annulus 38 and touches the opposite wall. The other species of ribs 42 only partially protrudes into the outer annulus 38 into it.

At an in 7 shown variant are only in the outer annulus 38 protruding ribs 42 intended. The ribs are T-shaped in cross-section and thus engage behind each other. This allows a particularly high surface area for heat transfer between the refrigerant 12 in the outer annulus 38 and the corresponding walls are achieved.

In 8th and 9 are two different variants for the low pressure inlet adapter 82 shown. At the in 8th illustrated variant, the low pressure inlet adapter 82 a cylindrical inlet section 94 on top of a central hole 96 having. From the central hole 96 branch out two sub-channels 98 , each in two outlet sections 100 lead. The inlet section 94 is formed such that it from the interior 52 of the heat exchanger 26 in the inlet pipe 56 can be used. The two outlet sections 100 are designed that they are from the outside into the inlet holes 78 of the refrigerant tank 28 can intervene.

At the in 9 variant shown is at the inlet section 94 additionally a filter element 102 provided by the low pressure inlet adapter 82 inflowing refrigerant 12 filters.

In the 10 and 11 are two variants of a low-pressure outlet adapter 88 shown. The low pressure outlet adapter 88 has a central longitudinal bore 104 and a transversely extending transverse bore 106 on. The transverse bore 106 lies in the later installed state in the inner annulus 68 , The longitudinal bore 104 bumps against the ground on one side 86 of the refrigerant tank 28 and is thus through the ground 86 locked. An opposite opening of the longitudinal bore 104 is located in the outlet 60 of the heat exchanger 26 , This provides the low pressure outlet adapter 88 a fluid connection from the inner annulus 68 to the outlet 60 ,

At the in 11 illustrated variant of the low-pressure outlet adapter 88 is a filter element 102 provided, which from the Niederdruckauslassadapter 88 escaping refrigerant 12 filters.

In the interior 72 of the refrigerant tank 28 is a vortex generator 108 provided, which at the first axial end 76 of the refrigerant tank 28 is arranged. The vortex generator 108 is arranged such that the refrigerant passing through the inlet holes 78 in the interior 72 enters, swirls, in particular is set in rotation.

Axially adjacent thereto is a flow guide 110 arranged. The flow guide 110 has one of the inlet holes 78 facing conical surface 112 on. The conical surface 112 is to the inlet holes 78 convex, leaving the refrigerant 12 that through the inlet holes 78 in the interior 72 flows in at the conical surface 112 is directed radially outward, making it to the outer wall 114 of the refrigerant tank 28 is steered. As a result, solid and liquid phases of the refrigerant 12 on the outside wall 114 knock down, leaving them along the outside wall 114 towards the ground 86 of the refrigerant tank 28 to get promoted.

The flow guide 110 also has an inflow opening 116 on which to a center of the interior 72 is directed. Preferably, the inflow opening 116 arranged coaxially.

In order to hold back impurities is a filter element 118 provided, which in the inflow opening 116 is arranged.

refrigerant 12 coming from the refrigerant receiver 28 flows out through the flow guide 110 stream. Consequently, the refrigerant must 12 to the inlet opening 116 inflow and thus passes through the filter element 118 cleaned.

Furthermore, in the interior 72 a pipe 120 arranged, which as a suction tube 122 is trained. The pipe 120 forms a fluid connection between the interior 72 of the refrigerant tank 28 and the inner annulus 68 , For this purpose, the tube passes through 120 the outlet hole 80 in the refrigerant tank 28 ,

The pipe 120 runs starting from the flow guide 110 towards the ground 86 of the refrigerant tank 28 , Near the bottom 86 shows the tube 120 a bend 124 on, through which the pipe 120 is deflected substantially by 180 °.

Essentially 180 ° means a deviation of 180 ° of less than 10 °, preferably less than 5 °, particularly preferably less than 2 °. From the bend 124 out of the pipe extends 120 to the flow guide 110 and through it to the outlet hole 80 ,

refrigerant 12 coming from the refrigerant receiver 28 flows out, is at the flow guide 110 in the pipe 120 flowing through the pipe towards the bottom to flow at the bend 124 be diverted and through the pipe 120 from the refrigerant receiver 28 in the inner annulus 68 flow.

At the bend 124 is a suction opening 126 in the tube 120 educated. Through the suction opening 126 may be liquid, in particular lubricant, for example. Oil of the compressor, which is in the refrigerant collecting area 74 of the refrigerant tank 28 accumulates, be sucked. Due to the flow of the refrigerant 12 in the tube 120 the oil gets into the pipe through the Venturi effect 120 directed. The oil is thus together with the refrigerant 12 from the refrigerant receiver 28 promoted. Thus, an oil discharge device 127 educated.

On the ground 86 of the refrigerant tank 28 may be an oil filter element 128 be provided, preferably covers the oil filter element 128 the suction opening 126 off, leaving the oil in the pipe 120 sucked is freed from contamination.

In the production of the same parts 48 . 70 . 90 a negative mold is produced for the identical parts. In the negative mold, a material from which the corresponding components are to be manufactured, initiated.

The material is aluminum or an aluminum alloy provided. Before the material is introduced into the negative mold, the material is placed in a paste-like, thixotropic state. This is done in particular by heating. Alternatively or additionally, it is provided that the material is additionally kneaded.

The thixotropic state is characterized in particular by a mixing phase between liquid and solid parts. The solid parts are finely distributed in a continuous liquid phase. At rest, the material is thus firm, since the solid phases wedged against each other. As shearing forces are applied to the material, the solid particles begin to shift against each other so that the material behaves like a liquid. This behavior is also called thixotropic.

Before introducing the material into the negative mold, the negative mold is preheated, in particular to a temperature at which the material can reach a thixotropic state.

The introduction of the material into the negative mold takes place so slowly that a laminar flow of the material is made possible. As a result, defects, such as voids or pores can be avoided. Nevertheless, a training of very fine structures is possible.

Due to the lack of imperfections, the finished body has a higher strength than, for example, a manufactured by die-cast aluminum component. Thus, lower wall thicknesses of the components can be achieved. In addition, the components manufactured in this way are weldable.

Alternatively or additionally, it may be provided that as material for the refrigerant collecting container 28 Plastic is used and that the refrigerant tank 28 produced by plastic injection molding.

Due to the smaller wall thickness of the components may be in the outer annulus 38 and the inner annulus 68 each a desiccant 131 be provided, which otherwise usually in the refrigerant collecting area 74 are arranged and thereby the volume of the refrigerant collecting area 74 reduce.

An in 12 illustrated second embodiment of the heat exchanger device 10 is different from the one in the 1 to 11 shown first embodiment of the heat exchanger device 10 in that the pipe 120 the oil discharge device 127 straight. The pipe 120 extends from the flow guide 110 towards the ground 86 of the refrigerant tank. If refrigerant 12 from the refrigerant receiver 28 this does not necessarily flow through the pipe 120 stream. The refrigerant 12 can through the inlet opening 116 in the flow guide 110 inflow and over an outflow opening 117 from the flow guide 110 and thus from the refrigerant receiver 28 flow out.

If the refrigerant 12 through the inlet opening 116 in the flow guide 110 flows, it flows at a first end of the tube 120 over and that way at the opening of the pipe 120 generate a negative pressure through which liquid, in particular lubricant, for example oil, from the pipe 120 can be sucked.

The diameter of the pipe 120 is chosen such that due to the capillary effect, the oil at least partially into the tube 120 is sucked. Due to the combined effect of capillary effect and Venturi effect, the oil from the ground 86 of the refrigerant tank 28 be sucked off. Thus, the tube 120 a suction tube 122 ,

At a bottom end of the pipe 120 is the oil filter element 128 arranged and covered at the end of the tube 120 formed suction opening 126 ,

Incidentally, the in 12 illustrated second embodiment of the heat exchanger device 10 with the in the 1 to 11 shown first embodiment of the heat exchanger device 10 with regard to structure and function, to the above description of which reference is made.

An in 13 illustrated third embodiment of the heat exchanger device 10 is different from the one in the 1 to 11 shown first embodiment of the heat exchanger device 10 in that the oil discharge device 127 a straight pipe 120 in the refrigerant receiver 28 is arranged. The pipe 120 serves as a guide for a control rod 130 which a drive plate 132 with a valve body 134 combines.

The valve body 134 forms together with an oil discharge opening 136 which are in the ground 86 of the refrigerant tank 28 formed is a Ölaustragsventil 138 when the valve body 134 through the control rod 130 from the oil discharge opening 136 can be lifted, oil that is on the ground 86 of the refrigerant tank 28 has accumulated, from the refrigerant tank 28 flow out.

The drive plate 132 covers an outflow opening 117 the flow guide 110 , refrigerant 12 coming from the refrigerant receiver 28 flows out through this outflow opening 117 stream. This raises the refrigerant 12 the drive plate 132 on to the outflow opening 117 to open. By lifting the drive plate 132 is over the control rod 130 also the valve body 134 raised so that the oil discharge valve 138 is opened. Thus, the oil discharge valve 138 through the flow of the refrigerant 12 controlled.

In this way it can be achieved that at regular intervals, oil is drained from the refrigerant receiver and thereby can be returned to the compressor.

Incidentally, the in 13 illustrated third embodiment of the heat exchanger device 10 with the in the 1 to 11 shown first embodiment of the heat exchanger device 10 with regard to structure and function, to the above description of which reference is made.

An in 14 illustrated fourth embodiment of the heat exchanger device 10 is different from the one in 13 illustrated third embodiment of the heat exchanger device 10 in that the oil discharge device 127 instead of an oil discharge valve 138 a reciprocating pump 140 having. The reciprocating pump 140 is via the drive plate 132 and the control rod 130 driven.

The control rod 130 is with a piston 142 the reciprocating pump 140 connected. The piston 142 can in a cylinder 144 which is in the pipe 120 is formed, moved back and forth. In the pipe 120 is in the area of the cylinder 144 an oil suction port 146 arranged laterally, through which oil into the cylinder 144 can be sucked. In a rest position, the piston is 142 at a lowest position, at which the piston 142 the floor 86 is close. In this lowest position is the Ölansaugöffnung 146 Approved. Will the piston 142 through the drive plate 132 from the ground 86 Lifted away, the piston closes 142 the oil suction port 146 , On the way up to an upper end position can thus be built pressure to the oil from the refrigerant receiver 28 to transport.

In the tube is a check valve 148 formed, through which the oil from the cylinder 144 can flow out. By training as a check valve 148 prevents the check valve 148 that the oil is back in the cylinder 144 can flow. This can be achieved by an up and down movement of the piston 142 the oil will be gradually pumped out.

Preferably, the check valve 148 a valve ball 150 on which by a spring 152 against a conical valve seat 154 is pressed. The conical valve seat 154 encloses a valve opening 156 which has an opening to the cylinder 144 represents.

Incidentally, the in 14 illustrated fourth embodiment of the heat exchanger device 10 with the in 13 illustrated third embodiment of the heat exchange device 10 with regard to structure and function, to the above description of which reference is made.

Claims (16)

Method for producing a heat exchanger device ( 10 ) for a refrigeration system, in particular for a refrigeration system which works with CO ₂ , - with a housing ( 22 ), in which a high-pressure channel ( 18 ) and a low pressure channel ( 20 ) for a refrigerant ( 12 ), - with a heat exchanger ( 26 ), which the high-pressure channel ( 18 ) and the low pressure channel ( 20 ) fluidly separated and thermally coupled, and - with a refrigerant receiver ( 28 ) located in the low pressure channel ( 20 ) is arranged, - between the housing ( 22 ) and the heat exchanger ( 26 ) an outer annulus ( 38 ) is formed, - between the heat exchanger ( 26 ) and the refrigerant receiver ( 28 ) an inner annulus ( 68 ), characterized in that - for the manufacture of the housing ( 22 ), the heat exchanger ( 26 ) and / or the refrigerant receiver ( 28 ) a material is brought into a thixotropic state by heating, - that aluminum or an aluminum alloy is used as the material, and - that the material is passed in the thixotropic state into a negative mold. A method according to claim 1, characterized in that the material is passed laminar in the negative mold. Method according to claim 1 or 2, characterized in that on an outer side ( 64 ) of the heat exchanger ( 26 ) Ribs ( 42 ) formed in the outer annular space ( 38 ) protrude. Method according to one of claims 1 to 3, characterized in that on an inner side ( 66 ) of the heat exchanger ( 26 ) Ribs ( 42 ) formed in the inner annulus ( 68 ) protrude. Method according to one of claims 1 to 4, characterized in that - two identical parts ( 70 ) of the heat exchanger ( 26 ), and - that the common parts ( 70 ) of the heat exchanger ( 26 ). Method according to one of claims 1 to 5, characterized in that on an outer side ( 92 ) of the refrigerant receiver ribs ( 42 ) formed in the inner annulus ( 68 ) protrude. Method according to one of Claims 1 to 6, characterized in that - two identical parts ( 90 ) of the refrigerant receiver ( 28 ), and - that the common parts ( 90 ) of the refrigerant receiver ( 28 ). Method according to one of claims 1 to 7, characterized in that on an inner side ( 46 ) of the housing ( 22 ) Ribs ( 42 ) formed in the outer annular space ( 38 ) protrude. Method according to one of claims 1 to 8, characterized in that - two identical parts ( 48 ) of the housing ( 22 ), and - that the common parts ( 48 ) of the housing ( 22 ). Method according to one of claims 1 to 9, characterized in that on an outer side ( 44 ) of the housing ( 22 ) a grid structure is formed. A method according to claim 10, characterized in that the grid structure on the outside ( 44 ) of the housing ( 22 ) forms a triangular or quadrangular grid. Method according to one of claims 2 to 11, characterized in that the housing ( 22 ), the heat exchanger ( 26 ) and the refrigerant receiver ( 28 ) are arranged such that the respective mutually facing ribs ( 42 ) mesh. Refrigeration system for CO ₂ with a refrigerant circuit in which refrigerant ( 12 ) circulates during operation, with a compressor for driving the refrigerant ( 12 ), with an expansion valve, which separates a high pressure area and a low pressure area of the refrigerant circuit from each other, with a gas cooler for cooling the refrigerant ( 12 ) in the high-pressure region, with an evaporator and with a heat exchanger device ( 10 ) produced by a method according to any one of claims 1 to 12, wherein the high-pressure channel ( 18 ) of the heat exchanger device ( 10 ) is connected in the high pressure region of the refrigerant circuit downstream of the gas cooler and upstream of the expansion valve, and wherein the low pressure channel ( 20 ) of the heat exchanger device ( 10 ) is arranged in the low-pressure region of the refrigerant circuit downstream of the expansion valve. Refrigeration system according to claim 13, characterized in that the heat exchanger device ( 10 ) is connected in the refrigerant circuit such that the high-pressure channel ( 18 ) and the low pressure channel ( 20 ) are flowed through in countercurrent or cross flow or a mixed form thereof. Refrigeration system according to claim 13 or 14, characterized in that the refrigerant ( 12 ) CO ₂ is.  Motor vehicle with a refrigeration system according to one of claims 13 to 15.

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