EP2972047A1

EP2972047A1 - Cooler

Info

Publication number: EP2972047A1
Application number: EP14707782.0A
Authority: EP
Inventors: Harald Rieger; Hartmut Sauter; Hartmut Sohla
Original assignee: Mahle International GmbH
Current assignee: Mahle International GmbH
Priority date: 2013-03-08
Filing date: 2014-03-04
Publication date: 2016-01-20
Also published as: US20160010596A1; JP2016510868A; US9404447B2; CN105121991B; BR112015019078A8; KR20150123941A; DE102013203963A1; KR101630139B1; JP6068686B2; WO2014135518A1; CN105121991A; BR112015019078A2

Abstract

The present invention relates to a cooler (18) for cooling a gas flow (25), particularly for an internal combustion engine (1), preferably for a motor vehicle, comprising a cooler block (23), which has a gas path (27) through which the gas flow (25) can flow and a coolant path (28) through which a coolant can flow, the gas path and the coolant path being thermally coupled to each other in a media-separated manner. The risk of condensate in the gas flow can be reduced by means of a liquid separator (24) for separating liquid from the gas flow (25), which liquid separator is arranged on the cooler block (23) on an outlet side (26) of the gas path (27).

Description

cooler

The present invention relates to a cooler for cooling a gas flow, in particular an exhaust gas recirculation cooler for cooling recirculated exhaust gas. The invention also relates to a use of such a cooler.

A cooler usually comprises a radiator block which has a gas path through which the gas flow can flow and a coolant path through which a coolant can flow, which are thermally coupled to one another in a media-separated manner.

In vehicles such coolers are used in many ways. A particular application arises in the exhaust gas recirculation, in which exhaust gas from an exhaust system is externally supplied to a fresh air system to mix the recirculated exhaust gas with the fresh air upstream of combustion chambers of an internal combustion engine. Such exhaust gas recirculation (EGR) has proven to be advantageous in terms of fuel consumption and pollutant emissions of the internal combustion engine. In supercharged internal combustion engines, a distinction is made between high-pressure exhaust gas recirculation (HP-EGR) and low-pressure exhaust gas recirculation (LP-EGR). A supercharged internal combustion engine is equipped with an exhaust gas turbocharger, the turbine is arranged in the exhaust system and the compressor is arranged in the fresh air system. The compressor and turbine subdivide the fresh air system and the exhaust system into a high-pressure area and a low-pressure area. The fresh air side low pressure region extends upstream of the compressor. The fresh-air-side high-pressure region extends downstream of the compressor. The exhaust side low pressure region extends downstream of the turbine. The exhaust gas-side high-pressure region extends upstream of the turbine. High-pressure exhaust gas recirculation (HD-EGR) thus takes place upstream of the turbine and downstream of the turbine Compressor. In contrast, low-pressure exhaust gas recirculation (LP EGR) takes place downstream of the turbine and upstream of the compressor.

The exhaust gas may contain water in the form of water vapor, which may be produced by the combustion processes. Also may be contained in the sucked from the environment fresh air water in the form of water vapor. The recirculated exhaust gas is usually cooled by means of an exhaust gas recirculation cooler, for example, to increase the mass flow of fresh air. Depending on the ambient conditions, the recirculated exhaust gas can cool below the dew point of water, as a result of which condensation can occur, so that liquid water is obtained. This can form drops that can damage downstream following components. Both mechanical and corrosive damage is possible. In particular, a compressor wheel, which rotates in the compressor at high speed, is exposed by the collision with droplets of increased risk of damage. Furthermore, condensate can precipitate and freeze in adverse environmental conditions. Again, in particular, the compressor wheel is exposed to increased risk.

Particularly critical is the risk of condensation in a low-pressure exhaust gas recirculation, since there the recirculated exhaust gas is cooled regularly to a lower temperature level than in a high-pressure exhaust gas recirculation.

Preferred embodiments of such coolers are thus EGR coolers, which can be integrated into a low-temperature cooling circuit (NT cooling circuit) for a particularly high cooling capacity, ie in particular in a liquid cooling circuit, preferably a conventional engine cooling circuit. Such NT EGR coolers can be used, in particular in commercial vehicles, in the HD range or in the LP range, so that it is then NT-HD AGR cooler or NT-ND EGR cooler. The exhaust gas may contain, besides the water vapor, various combustion residues which are present in particulate form. In particular, the combustion residues may contain carbon black, mineral components, ceramic particles or silicates.

Coolers of the type mentioned can also be used in buildings, in particular for air conditioning of the room air. Further possible uses of such coolers are, for example, battery cooling, e.g. in electric vehicles, or in connection with an air supply of fuel cells. The respective gas flow may, in addition to liquids or condensate, also include solids, e.g. Dust, silicates (e.g., sand) or organic matter.

The present invention is concerned with the problem, for a cooler of the type mentioned, which may be designed in particular as exhaust gas recirculation cooler, to provide an improved embodiment or a novel use, which is characterized in that the risk of damage in the event of condensation Components is reduced.

This problem is solved according to the invention by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea of equipping the cooler with a liquid separator. With the aid of such a liquid separator, liquid can be separated from the gas flow, so that the gas flow emerging from the cooler contains no or only a reduced amount of liquid. Consequently, the risk of damage is reduced subsequent components. Suitably, the liquid separator is arranged on an outlet side of the gas path on the radiator block. This ensures that as much liquid as possible can be captured by the liquid separator, which accumulates within the gas path. Liquid, which precipitates in the gas path upstream of the outlet side, is transported by the gas flow in the direction of the outlet side and thus fed to the liquid separator.

According to an advantageous embodiment, the liquid separator may have a gas channel which has a channel cross-section through which the gas flow can pass and which is largely blocked by at least one deposition structure through which the gas flow can flow. Since the deposition structure completely or at least substantially obstructs the channel cross-section, the gas flow is forced to flow through the deposition structure. As a result, entrained liquid and / or solid impurities can accumulate on the deposition structure and be separated from the gas flow.

According to a development can connect in the direction of gravity a collecting duct to the channel cross-section, which extends transversely to the gas channel, which is open to the gas channel and which is arranged so that a drip edge of the at least one deposition structure in the direction of gravity adjacent thereto. In this way, the deposited impurities can be removed particularly easily from the deposition structure. Preferably, the respective drip edge is arranged outside the channel cross section of the gas channel and for this purpose within the collecting channel, whereby the dripping of the deposited impurities is improved in the collecting channel.

Appropriately, a drain line is connected to the collection channel to dissipate the deposited impurities, for example to a memory. Particularly efficient is an embodiment in which a plurality of deposition structures are arranged in series in the gas channel. The individual deposition structures can be designed identically or equipped with different separation effects. Suitably, the adjacent Abscheidestrukturen are arranged spaced from each other.

Preferably, the respective deposition structure may be formed by a hydrophobic tissue. Preferably, a metal mesh, e.g. made of steel or stainless steel. However, ceramic fabrics are also conceivable.

A simplified structure results when the respective deposition structure is arranged on a carrier which extends transversely through the channel cross section. As a result, the respective deposition structure itself can be relatively limp, which allows the use of materials and structures which have relatively low flow resistances and / or high separation effects.

In addition, the liquid separator may include a housing that contains the gas channel and that is attached to the radiator block. As a result, the liquid separator represents a separate assembly, which can be particularly easy to grow on the radiator block as needed.

According to an advantageous embodiment, the gas path in the radiator block can have a plurality of wall surfaces, on which a liquid film can form. The liquid separator then expediently immediately adjoins a gas-end-side end face of the radiator block which has the wall surfaces and conducts the liquid film therefrom. In this embodiment, the liquid separator serves primarily to receive and discharge the liquid film flowing along the wall surfaces, so that droplet formation in the gas stream can be avoided. In addition, the liquid Separators also already deposited in the gas stream entrained droplets that can form, for example, already within the cooler.

In an expedient development of the liquid separator may have webs which connect directly to the gas outlet side end face of the radiator block and direct the liquid film to a collecting structure of the liquid separator. With the aid of these webs is achieved that the liquid film, which can not flow along the gas outlet side end face of the radiator block along this end side due to gravity, but strikes the webs and is forwarded by them to the collecting structure. In particular, the wall surfaces on which the liquid film is formed delimit individual gas passages in the radiator block, which can be arranged adjacent to one another, in particular, in the direction of the gravitational force. If a liquid film on a wall surface emerges from such a gas channel, gravity drives it in the direction of the next underlying gas channel. There, drops could form and be taken away by the gas flow. Since such a flow to the next gas channel can be prevented with the aid of the webs, droplet formation in the gas flow can thereby also be avoided efficiently.

According to another development, the liquid separator may have a plate body which extends transversely to the gas flow, has gas passages aligned with gas outlet openings of the cooler block and from which the webs project. The aforementioned gas ducts have the exit openings of the radiator block on the outlet side. By the complementarily designed to the outlet side of the radiator block plates body, such that the passage openings of the plates body axially aligned to the outlet openings of the radiator block, ie in the flow direction of the gas flow, there is only a comparatively low flow resistance through the plate body and thus by the liquid separator. In addition, points the liquid separator thereby a comparatively simple structure. In particular, the plate body with the protruding webs can be made integrally from one piece.

In principle, the fiber structure can have any structure suitable for receiving liquid, in particular also a hydrophobic structure. According to a preferred embodiment of the plate body, however, may have a hydrophilic fiber structure that receives the liquid film. As a result, the liquid film can be rapidly removed from the gas flow, whereby the risk of entrainment of droplets is reduced by the gas flow.

In another embodiment, the liquid separator may have Ableitspalte that connect transversely to the gas flow direction directly to the gas-side outlet ends of the wall surfaces, so that the liquid film from the respective wall surface can enter into the respective discharge gap and is derivable therein. In contrast to the aforementioned embodiment, in which the webs derive the liquid film flowing out of the gas ducts on the outlet side, in this embodiment the discharge gaps ensure that the respective liquid film can flow away from the region of the gas flow transversely to the gas flow.

In principle, the respective liquid film can enter the respective discharge gap due to gravity. According to a particularly advantageous development, however, it may be provided to dimension the respective discharge gap so that capillary forces suck in and discharge the liquid film into the discharge gap. The Ableitspalte, which extend transversely to the gas flow direction, are thus dimensioned parallel to the gas flow direction relatively small in order to use the capillary forces can. The capillary forces cause a particularly efficient suction of the liquid film, without additional energy-consuming measures are required.

In another development, the liquid separator may have a fiber structure which adjoins the respective discharge gap and / or is arranged in the respective discharge gap. In principle, the fiber structure can have any structure suitable for receiving and discharging liquid, in particular also a hydrophobic structure. However, it is preferably a hydrophilic fiber structure. The fibrous structure absorbs the liquid film and can pass it within the liquid separator.

In another development, the liquid separator may comprise a plate body which extends transversely to the gas flow, which has aligned through openings to gas outlet openings of the radiator block and which has a protruding web structure, which abut directly on the gas outlet side end face of the radiator block, so that the Ableitspalte by the gas outlet-side end face and a cooler block facing the inside of the plate body are limited. This results in an extremely compact design for the liquid separator. It is also noteworthy that the liquid separator is completed only by the attachment of the plate body on the radiator block and functional.

In another advantageous embodiment, the liquid separator may have a fiber structure which extends completely over a gas outlet-side end side of the radiator block, which can be traversed by the gas flow and receives and discharges the liquid emerging from the gas path. In principle, the fiber structure can have any structure suitable for receiving and discharging liquid, in particular also a hydrophobic structure. However, it is preferably a hydrophilic fiber structure. at In this embodiment, the liquid separator has an extremely simple structure, which can be realized particularly inexpensively.

According to an advantageous development can be provided that the fiber structure is arranged in the gas flow direction spaced from the radiator block. This ensures that the fiber structure provides substantially more volume that can be flowed through than with an arrangement of the fiber structure directly on the radiator block. As a result, the flow resistance of the fiber structure can be significantly reduced.

The fiber structure may be a single-layer or multi-layer fabric or knit. This may be a ceramic or a metallic fiber structure. Likewise, a fiber structure made of plastic can be used.

In another advantageous embodiment, the liquid separator can have a store for separated liquid and an evaporator for evaporating the separated liquid. With the help of the evaporator, the memory can be emptied again. In this embodiment, the fact is taken into account that a condensate formation in the radiator, especially when used as a low-pressure side exhaust gas recirculation cooler, only under certain environmental conditions or operating conditions, while in many other environmental conditions or operating conditions no condensation occurs. In addition, operating conditions and environmental conditions prevailing, in which even an evaporation of water is possible. With the help of the memory can thus be collected for phases in which condensate accumulates, the separated condensate. With the help of the evaporator can then in phases, in which an evaporation of the condensate is possible, the memory to be emptied again. In this way, can be dispensed with an elaborate dissipation of the condensate in the environment.

The reservoir can optionally be equipped with an overflow to ensure the functionality of the liquid separator even when the storage tank is full. Additionally or alternatively, the memory may be equipped with baffles or with a surge structure. In particular, in vehicle applications, the dynamics of driving within the memory can accelerate the liquid, which can cause waves in the memory, which can cause the memory to spill over. As a result, stored liquid could be returned to the gas flow via the discharge structure. A

Swell structure counteracts the formation of waves, which also spilling over can be avoided.

According to another advantageous development, the evaporator can be temperature-controlled depending on the temperature of the gas flow downstream of the radiator block. This ensures that the evaporation is actively operated only at temperatures in the gas stream above the evaporation temperature of the water.

In a simple case, the evaporator may be a type of wick. The wick, due to capillary forces, promotes the separated water from the reservoir to a wick end exposed to the gas flow. At sufficient gas temperature it comes at the wick end to the desired evaporation of the liquid. A detachment of droplets, however, is not expected due to the high capillary forces in the wick. In another embodiment, the evaporator may operate with a pump which supplies the liquid from the reservoir to an evaporation surface during an evaporation operation, that is, at a sufficient gas temperature.

It is also possible to arrange a heater in the memory, with the help of which the liquid stored therein can be evaporated. The heater may be electrically operated, for example. It is likewise possible to realize the heating device by means of at least one so-called heat pipe which, for example, couples a bottom of the accumulator to the radiator block in order to transfer heat from the radiator block to the bottom of the accumulator.

Furthermore, the evaporator, for example, work with a suction jet pump, wherein the gas flow in a Venturi nozzle of the suction jet pump generates the negative pressure for sucking the liquid from the memory.

Additionally or alternatively, the evaporator may have corresponding valves in order to be able to actively control a supply of the liquid to the gas flow.

In another advantageous embodiment, the evaporator may deliver the separated liquid to vaporize the fibrous structure which during the deposition phase serves to receive the liquid from the gas flow or liquid film from the cooler block.

An inventive use of a cooler of the type described above takes place in an exhaust gas recirculation system for cooling recirculated exhaust gas. Accordingly, the present invention also relates to an exhaust gas recirculation cooler and an exhaust gas recirculation system with such exhaust gas recirculation cooler. Finally, the present invention also relates to an internal combustion engine with such an exhaust gas recirculation system. Preferably, the gas recirculation cooler in a low-pressure exhaust gas recirculation of a supercharged internal combustion engine for use.

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 below can be used not only in the particular combination given, but also in other combinations or in isolation, 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,

Fig. 1 is a greatly simplified schematic diagram of a schematic

Internal combustion engine,

2 shows a greatly simplified longitudinal section through a cooler in the region of a liquid separator,

Fig. 3 is an axial view of the liquid separator according to a

Detail III in Fig. 2, 4 is an isometric view of a plate body of the liquid separator,

5 is a sectional view as in Fig. 2, but in another embodiment,

6 is a sectional view as in Figures 2 and 5, but in a further embodiment,

7 is a sectional view as in Figure 6, but in another embodiment,

Fig. 8 is an axial view of the liquid separator at another

Embodiment, but without a deposition structure,

9 shows an axial section of the liquid separator from FIG. 8 according to FIG

Section lines IX in Fig. 8, but with deposition structures,

10 is an enlarged cross-sectional view of the liquid separator of FIGS. 8 and 9, but with a deposition structure corresponding to section lines X in FIG. 9.

1, an internal combustion engine 1 includes an engine block 2 having a plurality of combustion chambers 3, a fresh air system 4 for supplying fresh air to the combustion chambers 3, an exhaust system 5 for discharging exhaust gas from the combustion chambers 3, and an exhaust gas recirculation system 6 for returning exhaust gas from the exhaust system 5 to the fresh air system 4. The fresh air system 4 includes a fresh air filter 7, a compressor 8 of an exhaust gas turbocharger 9, a charge air cooler 10 and a throttle device 1 1, for example in the form of a throttle valve. The intercooler 10 is connected to a cooling circuit 12. The exhaust system 5 includes a turbine 13 of the exhaust gas turbocharger 9, which is connected via a drive shaft 14 to the compressor 8. Furthermore, the exhaust system 5 includes a catalyst 15 and a throttle device 16, for example in the form of a storage flap.

The exhaust gas recirculation system 6 includes an exhaust gas recirculation valve 17 and an exhaust gas recirculation cooler 18, which is connected to a cooling circuit 19. A removal point 20 of the exhaust gas recirculation system 6 is arranged here downstream of the turbine 13 on the exhaust system 5. An introduction point 21 of the exhaust gas recirculation system 6 is arranged upstream of the compressor 8 on the fresh air system 4. Accordingly, this is a low-pressure exhaust gas recirculation.

The cooling circuit 12 of the charge air cooler 10 and / or the cooling circuit 19 of the exhaust gas recirculation cooler 18 may be coupled to an engine cooling circuit 22. It can also be a separate cooling circuit.

The exhaust gas recirculation cooler 18, which is also referred to below generally as "cooler 18", according to the figures 1 to 6 comprises a cooler block 23 and a liquid separator 24 for separating liquid from a gas flow 25 which flows through the cooler block 23. The liquid separator 24 is arranged on a gas side exit side 26 of the radiator block 23.

The radiator block 23 has a gas flow path 27 through which the gas flow can flow, which is indicated by arrows in FIGS. 2, 5, 6 and 7. Furthermore, the radiator block 23 includes a recognizable in Figure 1 coolant path 28, which is traversed by a preferably liquid coolant. The coolant path 28 and the gas path 27 are thermal but media separated coupled together. Accordingly, the coolant path may remove heat from the gas path.

According to FIGS. 2 to 6, the gas path 27 in the radiator block 23 may contain a plurality of gas channels 29, which are bounded laterally by wall surfaces 30. During operation of the cooler 18, a liquid film 31 can form on these wall surfaces 30 under appropriate boundary conditions, namely by condensation of water vapor carried in the gas flow 25. This precipitate on the wall surfaces 30 then forms the liquid film 31, which emerges driven by the gas flow 25 from the gas channels 29.

According to FIGS. 2 to 4 and 5, the liquid separator 24 is connected directly to a gas outlet-side end face 32 of the radiator block 23, which coincides here with the outlet side 26 of the gas path 27. Thus, the liquid separator 24 can discharge the liquid film 31.

According to the embodiment shown in FIGS. 2 to 4, the liquid separator 24 may have webs 33 which directly adjoin the gas outlet-side end face 32 of the radiator block 23. The webs 33 lead the liquid film 31 emerging from the gas channels 29 to a collecting structure 34 of the liquid separator 24. Thus, the accumulated liquid according to FIG. 3 can be deflected laterally along the webs 33 transversely to the gas flow direction 35 and then along the collecting structure 34, for example downwards be dissipated.

Referring to FIG. 4, the liquid separator 24 may include a plate body 36 extending transversely to the gas flow direction 35. The plate body 36 has a plurality of through openings 37, which in terms of number, arrangement and dimensioning complementary to gas side outlet openings 38 of the heat sink 23 are designed. Accordingly, the passage openings 37 are arranged with respect to the gas flow direction 35 axially aligned with the outlet openings 38. The plate body 36 may have a hydrophilic fiber structure 39, which is indicated purely by way of example in Figure 4 on the right edge side of the plate body 36. It is clear that in principle the entire cooler block 23 facing the inner side 40 of the plate body 36 may be provided with such a fiber structure 39. The fiber structure 39 is configured so that it can receive the liquid film 31.

FIG. 5 shows another embodiment of the liquid separator 24, in which discharge gaps 41 are formed, which extend transversely to the gas flow direction 35 and thereby directly adjoin the gas-side outlet ends 42 of the wall surfaces 30. Accordingly, the respective liquid film 31 can enter from the respective wall surface 30 into the respective discharge gap 41, the respective liquid film 31, which enters such a discharge gap 41, being diverted in the discharge gap 41. Expediently, a gap width 43 is dimensioned so that capillary forces arise which suck the liquid film 31 into the discharge gap 41 and effect a discharge of the liquid in the discharge gap 41. For example, according to FIG. 5, liquid can collect at the respective outlet end 42 of the wall surface 30 in an inlet region 44 of the respective discharge gap 41 liquid transported with the liquid film 31 until it is sucked into the discharge gap 41 by the capillary forces and discharged thereinto.

Also in this embodiment, the liquid separator 24 may have a hydrophilic fiber structure 45, which may be arranged as in the example of Figure 5 within the respective discharge gap 41. It is also possible that the respective discharge gap 41 with its capillary action leads to such a fiber structure 45. Suitably, the liquid separator 24 in this embodiment also have a plate body 46 which extends transversely to the gas flow 25, which has through openings 47 aligned with the gas-side outlet openings 38 of the cooler block 23 and which has a web structure 48 protruding from the plate body 46. The web structure 48 comprises a plurality of webs 49, each of which abuts directly on the gas outlet-side end face 32 of the radiator block 23. In this way, the Ableitspalte 41 on the one hand by the gas outlet side end face 32 and on the other hand by a cooler block 23 facing the inner side 50 of the plate body 46 is limited.

According to FIGS. 6 and 7, the liquid separator 24 can also be formed by means of a hydrophilic fiber structure 51, which extends completely over the outlet-side end face 32 of the radiator block 23. The fibrous structure 51 can be traversed by the gas flow 25 and configured so that it can receive and discharge the liquid emerging from the gas path 27. In the specific embodiment shown in FIGS. 6 and 7, the fiber structure 51 is arranged at a distance from the exit-side end face 32 of the radiator block 23 in the gas flow direction 35. As a result, the entire surface of the fiber structure 51 is available for the flow and flow through the gas flow 25, whereby the flow resistance of the fiber structure 51 is reduced. The fibrous structure 51 may be a ceramic or metallic knit or knit. The fiber structure 51 may be single-layered or multi-layered. In the example of FIGS. 6 and 7, a three-layer fiber structure 51 is indicated. An embodiment in which the individual layers of the fibrous structure 51 maintain a predetermined distance relative to one another, which is particularly suitable for receiving and removing drops of liquid from the gas flow 25, is particularly advantageous in the case of a multilayer fibrous structure 51. In the embodiment shown in FIG. 7, in addition to the embodiment shown in FIG. 6, the liquid separator 24 is equipped with a reservoir 52 which can store the separated liquid. Accordingly, the respective liquid separator 24 may be configured to supply the separated liquid to this reservoir 52. Such a memory 52 may be implemented in all embodiments shown here.

Furthermore, FIG. 7 shows an evaporator 53, with the aid of which the separated liquid can be evaporated from the accumulator 52. In operating phases in which condensate accumulates, this can be stored in the memory 52. In operating phases in which liquid can be evaporated, the memory 52 can be emptied again with the aid of the evaporator 53. In the example of FIG. 7, the accumulator 52 has an overflow 54, which can be controlled by a suitable valve 55. In the example of FIG. 7, a surge structure 56 is also arranged in the accumulator 52, for example in the form of a grid, which ensures that waves that may arise in the accumulator 52 during operation of a vehicle equipped with the internal combustion engine 1 do not cause the accumulators to overflow Can lead liquid.

The evaporator 53 is suitably temperature-controlled, depending on the temperature of the gas flow 25 downstream of the radiator block 23. In a particularly simple case, the evaporator 53 may have a wick, which promotes liquid according to Figure 7 to a gas flow 25 exposed area. Between the accumulator 52 and the radiator block 23 may also be arranged a heat pipe 57 to evaporate liquid from the accumulator 52.

In this case, the evaporator 53 may expediently be configured such that it feeds the separated liquid back to the fibrous structure 51 for evaporation. This can be done according to Figure 7 so that the evaporator 53 promotes the liquid into the region of the gas flow 25, such that there can detach droplets, which are collected and vaporized in the fiber structure 51. In FIG. 7, downstream of the fiber structure 51, a region is indicated in which the gas flow 25 contains water vapor.

According to FIGS. 8 to 10, the liquid separator 24 may have in a separate housing 58 a gas channel 59 which has a channel cross-section 60 through which the gas flow 25 can flow. The channel cross section 60 is now largely, preferably completely, blocked by at least one deposition structure 61, 62, which can be traversed by the gas flow 25. In the example, two such deposition structures 61, 62 are shown in FIG. 9, which are arranged one behind the other, ie in series in the flow direction of the gas flow 25, such that they are spaced apart in the flow direction of the gas flow 25. In principle, a single deposition structure 61, 62 may suffice; Likewise, more than two deposition structures 61, 62 may be provided.

The respective deposition structure 61, 62 is permeable to the gas flow 25, but forms for entrained particles and in particular for entrained liquid droplets an obstacle to which the particles or droplets can accumulate, whereby they are eliminated from the gas flow 25. For example, the respective deposition structure 61, 62 is a fabric of a hydrophobic material, such as e.g. a metal fabric, in particular of steel, preferably of stainless steel.

According to FIGS. 9 and 10, the liquid separator 24 has in its housing 58 a collecting channel 63 which adjoins the channel cross-section 60 in the direction of gravity 64 indicated by an arrow. The collection Channel 63 collects the separated from the respective deposition structure 61, 62 liquid and leads them to a drain line 65 to. The drain line 65 can lead to the memory 52, which has been explained with reference to the embodiment of Fig. 7. The collecting channel 63 extends transversely to the gas channel 59 and is open to the gas channel 59, that is opposite to the direction of gravity 64. Further, the collecting channel 63 is positioned so that a drip edge 66 of the respective Abscheidestruktur 61, 62 in the direction of gravity 64 adjacent thereto. Thus, liquid absorbed by the respective deposition structure 61, 62 within the deposition structure 61, 62 can flow off in the direction of the drip edge 66 due to gravity and drip off from it into the collection channel 63. It is advantageous if the respective drip edge 66 is already arranged outside the channel cross-section 60 of the gas channel 59 through which the gas flow 25 flows and dips into the collecting channel 63. Then, the liquid from the gas flow 25 undisturbed drain into the collecting channel 63. The collecting channel 63 is also designed here so that it tapers in the direction of gravity 64 to the discharge line 65 back.

For the respective deposition structure 61, 62 a support 67 or 68 is respectively provided, on which the respective deposition structure 61, 62 is arranged or fixed. The respective carrier 67, 68 extends transversely through the channel cross-section 60 and is formed, for example, by means of cross-shaped webs which generate only a small flow resistance.

Referring to FIGS. 8 and 10, the housing 58 has openings 69 with which the liquid separator 24 can be mounted on the radiator block 23, for example by means of a corresponding screw. According to FIG. 9, the housing 58 can have two housing halves 70 and 71, between which the respective carrier 67, 68 and / or the respective deposition structure 61, 62 can be clamped on the housing 58 for fixing.

*****

Claims

Expectations

1 . Cooler for cooling a gas flow (25), in particular in an internal combustion engine (1), preferably in a motor vehicle,

- with a cooler block (23), which has a gas path (27) through which the gas flow (25) can flow and a coolant path (28) through which a coolant can flow, which are thermally coupled to one another in a media-separated manner,

- With a liquid separator (24) for separating liquid from the gas flow (25), which is arranged on an outlet side (26) of the gas path (27) on the radiator block (23).

2. Cooler according to claim 1,

characterized,

in that the liquid separator (24) has a gas channel () which has a channel cross section () through which the gas flow (25) can flow and which is largely blocked by at least one separation structure () through which the gas flow (25) can flow.

3. Cooler according to claim 2,

characterized,

that in the direction of gravity (), a collecting channel () connects to the channel cross section (), which runs transversely to the gas channel (), which is open to the gas channel () and which is arranged in such a way that a drip edge () of the at least one separation structure () in the direction of gravity () is adjacent to it.

4. Cooler according to claim 2 or 3,

characterized,

that a drain line () is connected to the collecting channel ().

5. Cooler according to one of claims 2 to 4,

characterized,

that several separation structures () are arranged in series in the gas channel ().

6. Cooler according to one of claims 2 to 5,

characterized,

that the respective deposition structure () is formed by a hydrophobic fabric.

7. Cooler according to one of claims 2 to 6,

characterized,

that the respective separation structure () is arranged on a support () which extends transversely through the channel cross section ().

8. Cooler according to one of claims 2 to 7,

characterized,

that the liquid separator (24) has a housing () which contains the gas channel () and which is attached to the cooler block (23).

9. Cooler according to claim 1,

characterized,

- that the gas path (27) in the radiator block (23) has several wall surfaces (30) on which a liquid film (31) can form, - That the liquid separator (24) connects directly to a gas outlet end face (32) of the radiator block (23) and drains the liquid film (31).

10. Cooler according to claim 9,

characterized,

that the liquid separator (24) has webs (33) which connect directly to the gas outlet end face (32) of the radiator block (23) and direct the liquid film (31) to a collecting structure (34) of the liquid separator (24).

1 1 . Cooler according to claim 10,

characterized,

in that the liquid separator (24) has a plate body (36) which extends transversely to the gas flow direction (35), which has through openings (37) aligned with the gas-side outlet openings (38) of the radiator block (23) and from which the webs (33) protrude .

12 cooler according to claim 1 1,

characterized,

that the plate body (36) has a hydrophilic fiber structure (39) which absorbs the liquid film (31).

13. Cooler according to claim 9,

characterized,

that the liquid separator (24) has discharge gaps (41) which connect directly to the gas-side outlet ends (42) of the wall surfaces (30) transversely to the gas flow direction (35), so that the liquid film (31) is separated from the respective against wall surface (30) can enter the respective discharge gap (41) and can be derived therein.

14. Cooler according to claim 13,

characterized,

that the respective discharge gap (41) is dimensioned such that capillary forces suck the liquid film (31) into the discharge gap (41) and discharge it therein.

15. Cooler according to claim 13 or 14,

characterized,

that the liquid separator (24) has a hydrophilic fiber structure (45) which connects to the respective discharge gap (41) and/or is arranged in the respective discharge gap (41).

16. Cooler according to one of claims 13 to 15,

characterized,

in that the liquid separator (24) has a plate body (46) which extends transversely to the gas flow (25), which has through openings (47) aligned with gas-side outlet openings (38) of the radiator block (23) and which has a web structure (48) projecting therefrom which abuts directly on the gas outlet end face (32) of the radiator block (23), so that the discharge gap (41) passes through the gas outlet end face (32) and an inside (50) of the plate body (46) facing the radiator block (23). ) are limited.

17. Cooler according to claim 1,

characterized,

that the liquid separator (24) has a hydrophilic fiber structure (51) which extends completely over a gas outlet end face (32) of the radiator block (23), through which the gas flow (25) can flow and which receives and discharges the liquid emerging from the gas path (27).

18. Cooler according to claim 17,

characterized,

that the fiber structure (51) is arranged at a distance from the cooler block (23) in the gas flow direction (35).

19. Cooler according to one of claims 1 to 20,

characterized,

that the liquid separator (24) has a storage (52) for separated liquid and an evaporator (53) for evaporating the separated liquid.

20. Cooler according to claim 19,

characterized,

that the evaporator (53) is temperature-controlled depending on the temperature of the gas flow (25) downstream of the cooler block (23).

21. Cooler according to claim 17 or 18 and according to claim 19 or 20, characterized in

that the evaporator (53) supplies the separated liquid to evaporate the fiber structure (51).

22. Use of a cooler (18) according to one of claims 1 to 21 in an exhaust gas recirculation system (6) for cooling recirculated exhaust gas.