HEAT EXCHANGER AND METHOD OF OPERATION

Abstract

A heat exchanger of an electrically driven motor vehicle, which includes a tube/rib block having a multiplicity of tubes and having a multiplicity of ribs. The tubes being arranged essentially in parallel to each other and spaced a distance apart, and the ribs each being arranged between two adjacent tubes. The ribs touching the two adjacent tubes, at least one manifold being arranged on one of the sides of the tube/rib block for the purpose of supplying fluid to tubes of the tube/rib block and for removing fluid from tubes of the tube/rib block. A cover device is arranged downstream and/or upstream from the tube/rib block for controlling the air flow through the tube/rib block temporarily or in certain regions for the defined removal of water from the tube/rib block. A method for operating a heat exchanger is also provided.

Claims

1. A heat exchanger of an electrically driven motor vehicle, the heat exchanger comprising: a tube-rib block having at least two tubes and at least two ribs, the tubes being arranged essentially in parallel to each other and spaced a distance apart, and the ribs each being arranged between two adjacent tubes, the ribs touching the two adjacent tubes; at least one manifold arranged on one of the sides of the tube/rib block for the supplying fluid to tubes of the tube/rib block and for removing fluid from tubes of the tube/rib block; and a cover device arranged downstream and/or upstream from the tube/rib block for controlling air flow through the tube/rib block temporarily or in certain regions for the defined removal of water from the tube/rib block.

2. The heat exchanger according to claim 1, wherein the cover device has a plurality of regions, to which air flow control elements are assigned, which are adapted to be actuated individually, in groups, and/or together releasing or blocking the air flow through the region so that a region of the tube/rib block assigned to the region of the cover device has air flowing or not flowing through it.

3. The heat exchanger according to claim 2, wherein valve elements are provided as air flow control elements, which are designed as vane valves, butterfly valves, and/or as wing valves, which are rotatably coupled to at least one carrier element.

4. The heat exchanger according to claim 2, wherein at least one louver arrangement having a plurality of valves is formed as air flow control elements.

5. The heat exchanger according to claim 1, wherein the cover device comprises at least one rolling strip as the air flow control element, which has at least one strip region with at least one through-opening, the strip region having a movable design, so that the at least one through-opening may be movably arranged in a defined manner along an end face of tube/rib block.

6. The heat exchanger according to claim 1, wherein the cover device essentially directly abuts at least one end face of the tube/rib block or is arranged adjacent to at least one end face of the tube/rib block or is arranged at a distance from at least one end face of the tube/rib block.

7. The heat exchanger according to claim 6, wherein the cover device includes webs, which run between the end face of the tube/rib block and a carrier element, on/to which the air flow control element(s) is/are arranged or linked.

8. The heat exchanger according to claim 1, wherein the at least one air flow control element or the air flow control elements are adapted to be actuated individually, in groups, and/or together with the aid of at least one actuator.

9. The heat exchanger according to claim 1, wherein a first air channel and a second air channel are provided downstream from the tube/rib block, an air flow control element being provided, with the aid of which the second air channel is connected to the first air channel so that air may be conducted out of the second air channel into the first air channel or the second air channel is adapted to be disconnected from the first air channel so that the air from the second air channel is able to flow out independently of the first air channel.

10. A method for operating a heat exchanger according to claim 1, the method comprising: arranging the cover device downstream and/or upstream from the tube/rib block; and actuating the cover device for the control of an air flow through the tube/rib block temporarily or in certain regions for the defined removal of water from the tube/rib block such that an air flow is made to pass into the tube/rib block for removing water only in certain regions, wherein the cover device releases a through-flow of the tube/rib block in certain regions.

11. The method according to claim 10, wherein the region or some regions of the tube/rib block and/or the cover device is/are released consecutively in a targeted manner for the through-flow of the tube/rib block so that water is removed from the tube/rib block in certain regions and the corresponding regions are subsequently closed again.

12. The method according to claim 11, wherein, in a first operating mode, the regions of the tube/rib block and/or the cover device are released consecutively from top to bottom for the through-flow of the tube/rib block and subsequently closed again.

13. The method according to claim 11, wherein, in a second operating mode, the lower region or the lower regions of the tube/rib block and/or the cover device is/are released for the through-flow of the tube/rib block.

14. The method according to claim 10, wherein the water and the air used to remove the water are discharged directly into the surroundings or are discharged via an air channel open to the surroundings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0035] FIG. 1 is a schematic representation of an example of a heat exchanger according to the invention, including vertically arranged manifolds;

[0036] FIG. 2 is a schematic representation of an example of a heat exchanger according to the invention, including horizontally arranged manifolds;

[0037] FIG. 3 is a schematic sectional representation of an example of a heat exchanger according to the invention;

[0038] FIG. 4 is a schematic sectional representation of an example of a heat exchanger according to the invention;

[0039] FIG. 5 is a schematic representation of an example of a heat exchanger according to the invention, including horizontally arranged manifolds;

[0040] FIG. 6 is a schematic sectional representation of the heat exchanger in FIG. 5;

[0041] FIG. 7 is a schematic representation of an example of a heat exchanger according to the invention, including horizontally arranged manifolds;

[0042] FIG. 8 is a schematic sectional representation of the heat exchanger according to the invention;

[0043] FIG. 9 is a schematic sectional representation of the heat exchanger according to the invention; and

[0044] FIG. 10 is a schematic sectional representation of the heat exchanger according to the invention.

DETAILED DESCRIPTION

[0045] The invention relates to a heat exchanger, in particular for a coolant or refrigerant circuit, in particular for a refrigerant circuit of an electrically driven motor vehicle, and a method for operating a heat exchanger of this type.

[0046] FIG. 1 shows a heat exchanger 1 according to a first exemplary embodiment, for example for a refrigerant circuit, in a frontal view against the air flow direction of air L, which flows through tube/rib block 2 of heat exchanger 1. Instead of refrigerant, another fluid may also be usable.

[0047] Heat exchanger 1 is a heat exchanger 1, for example, of a refrigerant circuit, which may be used, for example, in an electrically driven motor vehicle as a condenser or gas cooler for an air-conditioning mode and/or as an evaporator for a heat pump mode.

[0048] Heat exchanger 1 includes a tube/rib block 2, which has a multiplicity of tubes 3 and a multiplicity of ribs 4.

[0049] Tubes 3 are arranged essentially in parallel to each other and spaced a distance apart. Tubes 3 of tube/rib block 2 are oriented horizontally in the exemplary embodiment in FIG. 1, i.e., transversely to gravitational direction G.

[0050] Ribs 4 are each arranged between two adjacent tubes 3 and touch the two adjacent tubes 3 for the purpose of improving the heat transfer between the medium flowing through tubes 3, for example a refrigerant, and the air flowing between ribs 4. Ribs 4 are preferably designed as corrugated ribs.

[0051] Tube/rib block 2 includes at least one manifold 5 on one of the sides of tube/rib block 2, preferably two manifolds 5, 6 on both sides of tube/rib block 2 (cf. FIG. 1), which are oriented essentially in parallel to each other and at a right angle to tubes 3 or their longitudinal direction.

[0052] Manifolds 5, 6 are preferably used to supply and distribute fluid, for example refrigerant, into tubes 3 of tube/rib block 2 and/or to collect and conduct fluid out of tubes 3 of tube/rib block 2.

[0053] Cover device 7 arranged on the back side of tube/rib block 2 is not apparent in FIG. 1. In the exemplary embodiment in FIG. 1, this cover device 7 is arranged completely upstream from tube/rib block 2 or from the air flow. As an alternative to the complete upstream arrangement of a cover device 7, a complete arrangement of cover device 7 downstream from tube/rib block 2 may also generally be provided. As a further alternative, a partially upstream cover device 7 with a partially downstream cover device 7 may be provided. In this alternative situation, cover device 7 would be arranged partially on both sides of tube/rib block 2 in each case.

[0054] A cover device 7 of this type is used to control the air flow through tube/rib block 2 temporarily and/or in certain regions for the defined removal of water from tube/rib block 2.

[0055] FIG. 2 shows a heat exchanger 1 according to a second exemplary embodiment, for example for a refrigerant circuit, in a frontal view against the air flow direction of air L, which flows through tube/rib block 2 of heat exchanger 1. Instead of refrigerant, another fluid may also be usable.

[0056] Heat exchanger 1 is a heat exchanger 1, for example, of a refrigerant circuit, which may be used, for example, in an electrically driven motor vehicle as a condenser or gas cooler for an air-conditioning mode and/or as an evaporator for a heat pump mode.

[0057] Heat exchanger 1 includes a tube/rib block 2, which has a multiplicity of tubes 3 and a multiplicity of ribs 4.

[0058] Tubes 3 are arranged essentially in parallel to each other and spaced a distance apart. Tubes 3 of tube/rib block 2 are oriented vertically in the exemplary embodiment in FIG. 2, i.e., in parallel to gravitational direction G.

[0059] Ribs 4 are each arranged between two adjacent tubes 3 and touch the two adjacent tubes 3 for the purpose of improving the heat transfer between the medium flowing through tubes 3, for example a refrigerant, and the air flowing between ribs 4. Ribs 4 are preferably designed as corrugated ribs.

[0060] Tube/rib block 2 includes at least one manifold 5 on one of the sides of tube/rib block 2, preferably two manifolds 5, 6 on both sides of tube/rib block 2 (cf. FIG. 2), which are oriented essentially in parallel to each other and at a right angle to tubes 3 or their longitudinal direction.

[0061] Manifolds 5, 6 are preferably used to supply and distribute fluid, for example refrigerant, into tubes 3 of tube/rib block 2 and/or to collect and conduct fluid out of tubes 3 of tube/rib block 2.

[0062] Cover device 7 arranged on the back side of tube/rib block 2 is not apparent in FIG. 2. In the exemplary embodiment in FIG. 2, this cover device 7 is arranged completely upstream from tube/rib block 2. As an alternative to the complete upstream arrangement of a cover device 7, a complete arrangement of cover device 7 downstream from tube/rib block 2 may also generally be provided. As a further alternative, a partially upstream cover device 7 with a partially downstream cover device 7 may be provided. In this alternative situation, cover device 7 would be arranged partially on both sides of tube/rib block 2 in each case.

[0063] In each disclosed exemplary embodiment, the cover device may generally be arranged downstream for the heat exchanger, upstream from the heat exchanger or both partially upstream and partially downstream from the heat exchanger.

[0064] A cover device 7 of this type is used to control the air flow through tube/rib block 2 temporarily and/or in certain regions for the defined removal of water from tube/rib block 2.

[0065] FIG. 3 shows a heat exchanger 1 according to a third exemplary embodiment, for example, for a refrigerant circuit, in a sectional representation, in which the air flow of air L is oriented from right to left in FIG. 3, so that the air flows through tube/rib block 2 of heat exchanger 1 according to arrows 10. Instead of refrigerant, another fluid may also be usable.

[0066] Heat exchanger 1 in FIG. 3 is a heat exchanger 1, for example, of a refrigerant circuit, which may be used, for example, in an electrically driven motor vehicle as a condenser or gas cooler for an air-conditioning mode and/or as an evaporator for a heat pump mode.

[0067] Illustrated heat exchanger 1 includes a tube/rib block 2, which has a multiplicity of tubes 3 and a multiplicity of ribs 4. Tubes 3 are arranged essentially in parallel to each other and spaced a distance apart. Tubes 3 of tube/rib block 2 are oriented vertically in the exemplary embodiment in FIG. 3, i.e., in parallel to gravitational direction G. Ribs 4 designed, for example, as corrugated ribs, are each arranged between two adjacent tubes 3 and touch the two adjacent tubes 3 for the purpose if improving the heat transfer between the medium flowing through tubes 3, for example a refrigerant, and the air flowing between ribs 4. Ribs 4 are preferably designed as corrugated ribs.

[0068] Tube/rib block 2 includes at least one manifold 5 on one of the sides of tube/rib block 2, preferably two manifolds 5, 6 on both sides of tube/rib block 2 (cf. FIG. 3), which are oriented essentially in parallel to each other and at a right angle to tubes 3 or their longitudinal direction.

[0069] Manifolds 5, 6 are preferably used to supply and distribute fluid, for example refrigerant, into tubes 3 of tube/rib block 2 and/or to collect and conduct fluid out of tubes 3 of tube/rib block 2.

[0070] It is apparent in FIG. 3 that a cover device 7 is arranged on the air inflow side of tube/rib block 2. In the exemplary embodiment in FIG. 3, this cover device 7 is arranged completely upstream from tube/rib block 2.

[0071] As an alternative to the complete upstream arrangement of cover device 7, a complete arrangement of cover device 7 downstream from tube/rib block 2 may also generally be provided. As a further alternative, a partially upstream cover device 7 with a partially downstream cover device 7 may be provided. In this alternative situation, cover device 7 would be arranged partially on both sides of tube/rib block 2 in each case.

[0072] A cover device 7 of this type is used to control the air flow through tube/rib block 2 temporarily and/or in certain regions for the defined removal of water from tube/rib block 2.

[0073] It is apparent in FIG. 3 that tube/rib block 2 has a water accumulation 8 distributed to different rib regions, which is present essentially in the lower region of tube/rib block 2 and in the middle region of tube/rib block 2, however a certain water accumulation 8 also being detectable in the upper region of tube/rib block 2.

[0074] Since the water accumulation may form in different ways over tube/rib block 2, it is advantageous if the air for the through-flow may be correspondingly distributed.

[0075] For this purpose, cover device 7 includes a plurality of regions 9, to which air flow control elements 11 are assigned, which may be actuated individually, in groups, and/or together for the purpose of releasing or blocking an air flow through particular region 9, so that a region of tube/rib block 2 assigned to region 9 of cover device 7 has air flowing or not flowing through it.

[0076] A total of six regions 9 of cover device 7 are apparent as examples in FIG. 3, which are situated one on top of the other in the direction of G and which each delimit a corresponding region of tube/rib block 2. One air flow control element 11 is assigned to each of regions 9 of cover device 7 for the purpose of closing or blocking particular region 9 or of releasing particular region 9 to allow are to flow through it. Instead of the six regions 9 illustrated, more or fewer regions 9 may also be provided.

[0077] Air flow control elements 11 may be opened alone or in pairs or in groups, for example one after the other, so that an upper region 9 or upper regions 9 is/are opened first and through which air flows. Water may thus be blown out or discharged from the upper region of the tube/rib block. Afterwards, the opened region or opened regions is/are closed again and blocked for a through-flow. A region 9 arranged lower down or regions 9 arranged lower down may subsequently be opened and have air flowing through them, as illustrated in FIG. 3. Water from a region 9 or regions 9 of tube/rib block 2 arranged lower down may thus be blown out or discharged. Afterwards, opened area 9 or opened areas 9 is/are closed again and blocked for a through-flow. Further regions 9 down to the bottom-most region 9 may subsequently be opened and have air flowing through them, until bottom-most region 9 has also be opened and has air flowing through it. Afterwards, opened area 9 or opened areas 9 is/are closed again and blocked for a through-flow. Alternatively, for example after the through-flow of bottom-most region 9, a driving action may be carried out in such a way that all air flow control elements 11 are subsequently driven to open regions 9 in order to operate heat exchanger 1 normally.

[0078] As is apparent from FIG. 3, in the exemplary embodiment, a region 9 is made up of an air flow control element 11 and two partition walls 12, which divide region 9 upwardly or downwardly in the manner of an air channel and separate it from adjacent regions 9. Cover device 7 includes a number of partition walls 12 of this type and air flow control elements 11, to be able to separate the particular regions from each other.

[0079] Air flow control elements 11 are drivable and movable by at least one drive, for example with the aid of at least one electric motor, at least one hydraulic drive unit, or at least one pneumatic drive unit. This drive may be coupled with air flow control elements 11 via a gearing or the like, for example with the aid of cam disks or the like. A separate drive may also be assigned to each air flow control element 11, or one drive may be assigned in each case to groups of air flow control elements 11.

[0080] It is also apparent from FIG. 3 that air flow control elements 11 may be folded up by cover device 7 in the direction of tube/rib block 2.

[0081] In the exemplary embodiment illustrated in FIG. 3, six regions 9 are provided, which are arranged one above the other. Regions 9 may be opened individually one after the other for a through-flow and then closed again to open a different region 9 and allow it to be flowed through. Regions 9 may be driven, for example, in pairs, so that, for example, first the two upper regions 9 are driven as pair I, then the two middle regions 9 are driven as pair II, and finally the two lower regions 9 are driven as pair III.

[0082] FIG. 4 shows a fourth exemplary embodiment of a heat exchanger 1 according to the invention, which essentially has a design similar to that of heat exchanger 1 in FIG. 3, for which reason reference is made to the description relating thereto. However, the heat exchanger in FIG. 4 differs from the heat exchanger in FIG. 3 in that cover device 7 has five regions 9, in which the through-flow of the air through tube/rib block 2 is controlled with the aid of air flow control elements 11. The air flow control elements also essentially abut tube/rib block 2 in the closed state, and partition walls 12, which are arranged in the air flow direction in FIG. 3, are omitted in the exemplary embodiment in FIG. 4. Air flow control elements 11 are pivotably arranged in such a way that they pivot away from tube/rib block 2.

[0083] In the exemplary embodiment illustrated in FIG. 4, five regions 9 are provided, which are arranged one above the other. Regions 9 may be opened individually one after the other for a through-flow and then closed again to open a different region 9 and allow it to be flowed through. Regions 9 may be driven, for example, in pairs, so that, for example, first the two upper regions 9 are driven as pair I, then the two middle regions 9 are driven as pair II, and finally individual lower region 9 is driven as region III. Instead of the five regions 9 illustrated, more or fewer regions 9 may also be provided.

[0084] In the two exemplary embodiments shown in FIGS. 3 and 4, air flow control elements 11 are designed as valve elements. The valve elements are designed as a kind of vane valve having an articulated linkage to one end of the valve surface.

[0085] Alternatively, it may also be advantageous if individual or all air flow control elements 11 are designed as butterfly valves and/or as wing valves, which are, for example, rotatably coupled to a carrier element.

[0086] It may also be alternatively advantageous if at least one louver arrangement having a plurality of valves is formed as air flow control elements 11.

[0087] It may also alternatively be advantageous if cover device 7 comprises at least one rolling strip as air flow control element 11, which has at least one strip region with at least one through-opening, the strip region having a movable design, so that the at least one through-opening may be movably arranged in a defined manner along an end face of tube/rib block 2.

[0088] Cover device 7 of the exemplary embodiment in FIG. 4 is designed in such a way that it essentially directly abuts at least one end face of tube/rib block 2 or is arranged adjacent to at least one end face of tube/rib block 2.

[0089] In the exemplary embodiment in FIG. 3, cover element 7 is arranged in such a way that it and/or its air flow control elements 11 is/are arranged at a distance from at least one end face of tube/rib block 2. Cover device 7 may also include webs as partition walls 12, which run between the end face of tube/rib block 2 and a carrier element 13, at/to which air flow control element(s) 11 is/are arranged or coupled.

[0090] FIGS. 5 and 6 show different representations of a fifth exemplary embodiment of a heat exchanger 1 according to the invention, including horizontally arranged manifolds 5, 6 and vertically arranged tubes of tube/rib block 2.

[0091] FIGS. 5 and 6 show a fifth exemplary embodiment of a heat exchanger 1 according to the invention, which essentially has a design similar to that of heat exchanger 1 in FIG. 4 and the heat exchanger in FIG. 3, for which reason reference is made to the description of FIG. 4 and the description of FIG. 3 relating thereto. However, the heat exchanger in FIG. 5 differs from the heat exchanger in FIG. 4 in that cover device 7 has five regions 9, in which the through-flow of the air through tube/rib block 2 is controlled with the aid of air flow control elements 11, the vertical size or the vertical height of regions 9 and air flow control elements 11 is not the same, but rather lower region 9 has approximately half the height hw compared to the other regions 9, which are arranged above lower region 9. Instead of the five regions 9 illustrated, more or fewer regions 9 may also be provided.

[0092] The representation in FIG. 5 has five regions 9. However, this number of regions 9 is only an example. Any other number would also be possible. Height hw of lower region 9 is approximately half the height of the other regions 9 in the exemplary embodiment in FIG. 5. However, this is dependent on the particular structural conditions. Height hw is the height at which water accumulates in the rib or corrugated rib and does not flow out without external influence. The water also remains standing at this height even if no water is added from above. It is held in the rib or corrugated rib by the capillary forces. To blow out this water column, the lower element is approximately the same height as this water column hw. A typical value is in the range from 5 mm to approximately 35 mm.

[0093] Air flow control elements 11 are arranged at a slight distance from tube/rib block 2 in the closed state, the distance being bridged by partition walls 12 as webs. Air flow control elements 11 are arranged in a pivotable manner. Lower air flow control element 11 is designed as a butterfly valve. Upper air flow control elements 11 are designed as butterfly valves or as the vane valve according to FIG. 3.

[0094] In the exemplary embodiment illustrated in FIG. 6, five regions 9 are provided, which are arranged one above the other. Regions 9 may be opened, for example, individually one after the other for a through-flow and then closed again afterwards to open another region 9 and allow it to be flowed through. Regions 9 may also be driven, for example, in pairs or in groups, so that, for example, first the two upper regions 9 are driven as pair I, then the two middle regions 9 are driven as pair II, and finally individual lower regions 9 is driven as region III. Instead of the five regions 9 disclosed in this regard, more or fewer regions 9 may also be provided.

[0095] FIGS. 7 and 8 show different representations of a sixth exemplary embodiment of a heat exchanger 1 according to the invention, including horizontally arranged manifolds 5, 6 and vertically arranged tubes of tube/rib block 2.

[0096] FIGS. 7 and 8 show a sixth exemplary embodiment of a heat exchanger 1 according to the invention, which essentially has a design similar to that of heat exchanger 1 in FIGS. 5 and 6, heat exchanger 1 in FIG. 4, and heat exchanger 1 in FIG. 3, for which reason reference is made to the description in FIG. 4, FIGS. 5 and 6 relating thereto, and to the description of FIG. 3. However, the heat exchanger in FIGS. 7 and 8 differs from the heat exchanger in FIGS. 5 and 6 in that cover device 7 is arranged both partially downstream and partially upstream from tube/rib block 2.

[0097] Cover device 7 in FIG. 8 has two regions 9, upper region 9 being arranged downstream from heat exchanger 1, and lower region 9 being arranged upstream from heat exchanger 1. An air flow control element 11 is assigned to each of the two regions 9 for the purpose of controlling the air flow through regions 9.

[0098] The vertical size or the vertical height of regions 9 and air flow control elements 11 is not the same, but instead lower region 9 has a significantly shorter height hw compared to the other region 9 arranged above. Upper region 9 may be partially or completely closed with the aid of associated air flow control element 11. Lower region 9 may advantageously also be partially or completely closed with the aid of associated air flow control element 11. The discussion above with respect to FIG. 5 also applies to hw.

[0099] Air flow control elements 11 are arranged at a slight distance from tube/rib block 2 in the closed state, the distance being bridged by partition walls 12 as webs. Lower air flow control element 11 is arranged in a pivotable manner, lower air flow control element 11 being designed, for example, as a butterfly valve. Upper air flow control element 11 is designed, for example, as a rolling strip. Other designs may also be provided here, for example those having multiple valve elements. In the case of a rolling strip, it would be advantageous, for example, if the rolling strip could be set to be completely open, open only over the height of hw, and/or completely closed.

[0100] FIGS. 9 and 10 show different operating situations of a seventh exemplary embodiment of a heat exchanger 1 according to the invention, including horizontally arranged manifolds 5, 6 and vertically arranged tubes of tube/rib block 2.

[0101] FIGS. 9 and 10 show a seventh exemplary embodiment of a heat exchanger 1 according to the invention, which essentially has a design similar to that of heat exchanger 1 in the preceding figures, for which reason reference is made to the description relating thereto.

[0102] A first air channel 20 and a second air channel 21 are provided downstream from tube/rib block 2, which partially conduct the air flow passing through heat exchanger 1. A first air flow control element 11 is arranged in or assigned to first air channel 20, so that the air flow through heat exchanger 1 may be blocked in the first air channel.

[0103] An air flow control element for blocking second air channel 21 is not illustrated but would optionally also be possible.

[0104] However, an air flow control element 22 is provided, which is arranged in a partition wall 23 between first air channel 20 and second air channel 21.

[0105] Second air channel 21 may be connected to first air channel 20 via opening 24 with the aid of air flow control element 22, so that air is conductible out of second air channel 21 into first air channel 20 through opening 24 when air flow control element 22 releases the opening.

[0106] Second air channel 21 may also be disconnected from first air channel 20, so that the air from second air channel 21 is able to flow out independently of first air channel 20. The air of first air channel 20 may be supplied, for example, to an air-conditioning system of the interior of the motor vehicle, and the air of second air channel 21 may be supplied, for example, to the surroundings or the outside air of the motor vehicle or the like.

[0107] Heat exchanger 1 according to the invention may be operated with the aid of a method for operating a heat exchanger 1.

[0108] For this purpose, provided cover device 7, which is situated downstream and/or upstream from tube/rib block 2, is actuated for controlling the air flow through tube/rib block 2 temporarily and/or in certain regions for the defined removal of water from tube/rib block 2.

[0109] The actuation may take place in such a way that a tube/rib block 2 is provided with an air inflow only in certain regions for the purpose of removing water, in that cover device 7 releases a through-flow of tube/rib block 2 only in certain regions. The available air flow is reduced thereby to a smaller cross-section by a blower or by a fan, which effectuates a higher air velocity in the open region, which effectuates an improved blowing out of water from the released region of tube/rib block 2. If the released surface area of tube/rib block 2 is varied in a targeted manner, for example consecutively from top to bottom, either entire tube/rib block 2 is freed of water or a release may also take place only in regions 9 of tube/rib block 2 which are especially affected by water accumulations.

[0110] In one advantageous embodiment of the method, regions 9, all regions 9, or some regions 9 of tube/rib block 2 and/or of cover device 7 may thus be released consecutively in a targeted manner for the through-flow of tube/rib block 2, so that water is removed from tube/rib block 2 in certain regions, and, in particular, corresponding regions 9 are subsequently closed again.

[0111] In a first operating mode, regions 9 of tube/rib block 2 and/or cover device 7 may be released consecutively from top to bottom, individually or in groups, for the through-flow of tube/rib block 2 and, in particular, subsequently closed again. Tube/rib block 2 may thus be blown free of water from top to bottom.

[0112] In a second operating mode, lower region 9 or lower regions 9 of tube/rib block 2 and/or cover device 7 may be released for the through-flow of tube/rib block 2. Tube/rib block 2 may thus be blown free of water at least in one lower region 9 or in lower regions 9.

[0113] In a further exemplary embodiment, it may also be advantageous if the water and the air used to remove the water are discharged directly into the surroundings or removed with the aid of an air channel open to the surroundings. This achieves the fact that the water is not conducted into the interior of the motor vehicle and, for example, results in the windows of the motor vehicle fogging up in cold weather.

[0114] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.