Heat exchanger, vehicle comprising a corresponding heat exchanger and method for operating a heat exchanger

Abstract

A heat exchanger (10) for a motor vehicle is proposed, comprising a first manifold (14) in a first end region (11) and a second manifold (15) in a second end region (12). The heat exchanger (10) comprises at least one discharge means (20) on a manifold for discharging condensate on the heat exchanger (10).

Description

[0001] The present invention relates to a heat exchanger, a vehicle comprising a corresponding heat exchanger, and a method for operating a heat exchanger according to the independent claims.

[0002] Heat exchangers are generally known from the prior art. The problem of condensate accumulating on the heat exchanger is also well known. For example, WO 2020 / 058585 A1 describes a front-end module for a motor vehicle, with a drain hole and at least one heat exchanger arranged in one of the walls. The front-end module includes a defrosting element designed to transfer the heat generated by the heat exchanger to the drain hole.

[0003] DE 10 2022 202 503 A1 relates to a heat exchanger comprising means for draining condensate from a tube-fin block.

[0004] DE 10 2020 200 079 A1 shows an outside air heat exchanger for a vehicle, wherein a collecting pipe can be provided with capillaries so that the capillary force supports the removal of water.

[0005] It is therefore generally known that heat pumps used in electromobility to heat vehicle interiors extract the heat required for heating from the outside air. As a prerequisite, the ambient heat exchanger must be cooled below the outside air temperature. However, if the outside air falls below its dew point, frost forms on the surface of the heat exchanger, preventing further air from flowing through the heat exchanger and reducing the efficiency of the heat pump. To enable airflow again, defrost cycles are necessary during which the heat exchanger is heated up. The ice then melts, and air flow through the heat exchanger can resume. During defrosting, the previously frozen condensate escapes from the heat exchanger as meltwater, where it can collect in the underbody of the heat exchanger or the underbody of the vehicle.Due to the cold surfaces, meltwater can freeze in the underbody areas. Excessive de-icing during a winter trip can cause malfunctions or failures of the heat pump system. Furthermore, the accumulated ice can damage other components.

[0006] The present invention is therefore based on the problem of further developing a heat exchanger in such a way that condensate is efficiently and reliably removed in order to guarantee a flow through the heat exchanger and thus counteract a reduction in efficiency.

[0007] The above-mentioned task is solved by a heat exchanger of a motor vehicle, especially a passenger vehicle, especially an electrically powered motor vehicle.

[0008] The heat exchanger can, in particular, be part of a heat pump. The heat exchanger can preferably be an external heat exchanger, i.e., an outside air heat exchanger, with the help of which the heat required to heat the interior of the vehicle is extracted. This heat exchanger has the problem that, when the temperature of the outside air is below the dew point, frost forms on it. The heat exchanger comprises, in particular, a coolant that flows through it and evaporates there. The medium flowing around the heat exchanger, i.e., preferably the outside air, is cooled in the process, and the coolant heats up. The heated coolant then flows into another heat exchanger of the heat pump in the passenger compartment, where the heat can then be released back into the interior air for heating purposes.

[0009] The heat exchanger comprises, in particular, a first header pipe in a first end region and a second header pipe in a second end region of the heat exchanger. The first end region is located, in particular, vertically above the second end region. In particular, the height direction of the heat exchanger extends vertically, while the longitudinal direction of the header pipe extends horizontally. Furthermore, the heat exchanger comprises a central region between the header pipes, in which pipes are also arranged that fluidically connect the header pipes to one another. These pipes extend primarily vertically between the two end regions.

[0010] The heat exchanger comprises at least one discharge means arranged on a manifold, in particular the second manifold. The discharge means serves to discharge condensate onto the heat exchanger. The condensate is in particular water that has condensed directly on the surface of the heat exchanger. This condensate can initially form as frost on the surface of the heat exchanger and then return to the liquid state during a defrost cycle. The discharge means is intended to ensure that this condensate is discharged and does not refreeze. The discharge means is deliberately arranged on a manifold. This is intended to use the heat of the warm refrigerant in the manifold to discharge the condensate or meltwater onto a warm surface so that it does not refreeze. Furthermore, frozen water in this area can also be defrosted and discharged again.

[0011] The discharge means is preferably not arranged in the central region of the heat exchanger in the longitudinal direction of the heat exchanger, where the tubes connecting the header tubes are located. Preferably, no discharge means is provided in this central region. The at least one discharge means extends primarily in a straight line.

[0012] In particular, the discharge means is attached to a collecting pipe. The discharge means can, in particular, be soldered to the collecting pipe. Preferably, the at least one discharge means is arranged laterally on a collecting pipe or is attached there. In particular, the at least one discharge means is arranged exclusively laterally on the collecting pipe and does not extend beyond the corresponding collecting pipe in the vertical direction extending between the first collecting pipe and the second collecting pipe.

[0013] Most preferably, the drainage means is a channel, especially a drainage channel. The channel is designed to collect the condensate and drain it away in a targeted manner. For this purpose, the drainage means can be arranged at an angle relative to a longitudinal direction of the collecting pipe.

[0014] The second collecting pipe is arranged in particular on an underbody of the motor vehicle, wherein the at least one discharge means can be arranged laterally on the second collecting pipe.

[0015] The drainage means can be arranged at an angle relative to the longitudinal direction of the collecting pipe. This inclined arrangement allows condensate to be drained away in a targeted manner, specifically along the slope of the drainage means. For this purpose, the drainage means can, in particular, form an angle of inclination with the longitudinal direction of the collecting pipe. This angle is in particular between 1° and 20°, preferably between 5° and 15°.

[0016] Preferably, two drainage means can be provided on a collecting pipe. These can be arranged laterally on the same side of the collecting pipe and each have a corresponding angle of inclination with the longitudinal direction of the collecting pipe. Each drainage means can extend over at least 30%, preferably at least 40%, most preferably almost 50% of the length of the collecting pipe. Both drainage means can have a respective gradient and can be responsible for drainage from the corresponding region of the collecting pipe. For example, both can be arranged such that condensate is drained outwards in the longitudinal direction starting from a central region of the collecting pipe. The drainage means can extend longitudinally across the collecting pipe.

[0017] Furthermore, only one drainage means can be arranged on the collecting pipe, extending over at least 60 percent, preferably at least 80 percent, of the length, most preferably over the entire length. This drainage means can, for example, include a bend in the middle and slope downwards, allowing the drainage means to transport condensate to the outside.

[0018] The drain can be made primarily of metal and thus effectively absorbs heat from the collector pipe. Each drain can be assigned to an outlet opening in the underbody of a vehicle and direct condensate there. The drain can then flow into the opening. Furthermore, the drain can extend through the outlet opening to thaw frozen water blocking the opening.

[0019] Furthermore, the at least one discharge means can be arranged perpendicular to a longitudinal direction of the header pipe. In other words, it can be arranged parallel to a vertical direction of the header pipe. In this case, a plurality of discharge means can be provided, which are arranged or fastened on the same side of the header pipe. These can be arranged equidistantly or at different distances from one another. More than three, preferably four or five, discharge means can be provided. In particular, these do not extend beyond the header pipe in the vertical direction of the heat exchanger. The at least one discharge means can be rod-shaped. Condensate can be discharged vertically therefrom towards the underbody of a vehicle. In this case, each discharge means can be assigned to an outlet opening in the underbody. The discharge means can, in particular, protrude into the outlet opening orprotrude through the outlet opening in order to thaw any ice that may be there.

[0020] Furthermore, the heat exchanger can comprise a housing. The housing can in particular extend around a manifold. The manifold is in particular the second manifold. The housing can in particular be a panel, preferably an underbody panel, which encloses the second manifold. The drainage means can be designed as a housing section, which can be arranged at a distance from the manifold. In other words, the housing is designed such that a distance and thus a gap is created between the manifold and the housing, with the housing section assigned to the gap acting as the drainage means. The housing section can in particular extend in a funnel shape towards the manifold in order to collect water in this area in a targeted manner. In other words, a gap is thus formed at the bottom of the underbody in the immediate vicinity of the manifold.The housing section can primarily be designed as a frame that encloses the collecting pipe.

[0021] In a further aspect, the invention relates to a vehicle comprising a heat exchanger described above. The vehicle can comprise at least one outlet opening mentioned above in the underbody, wherein a discharge means can be assigned to each outlet opening.

[0022] In a further aspect, the invention relates to a method for operating a heat exchanger of a motor vehicle as described above. Most preferably, this is a method for operating a heat pump comprising a corresponding heat exchanger. The method may comprise performing a defrost cycle and draining the resulting condensate using at least one draining means on a manifold of the heat exchanger.

[0023] They show in a purely schematic representation: Fig. 1: a perspective view of a heat exchanger, Fig. 2: a side view of a heat exchanger; Fig. 3: a side view of another heat exchanger; Fig. 4: a side view of another heat exchanger; Fig. 5: a plan view of the lower area of ​​another heat exchanger; Fig. 6: a sectional view of the heat exchanger of the Fig. 5; and Fig. 7: a process diagram of a process for operating a heat exchanger.

[0024] In Fig. 1, the installation position of a heat exchanger 10 is clearly visible. Namely, a first manifold 14 is located in a first end region 11 and a second manifold 15 is located in a second end region 12. Fig. 1 clearly shows the height direction 51 and the longitudinal direction 50 of the heat exchanger.

[0025] In particular, the height direction 51 corresponds to the vertical direction, while the longitudinal direction 50 corresponds to the horizontal direction. Fig. 1 shows an example of a refrigerant flow 40. In particular, tubes 13 extend between the first end region 11 and the second end region 12 in a central region, connecting the manifold tubes. Refrigerant is collected in the manifold tubes and distributed among the tubes.

[0026] In Fig. Figure 2 shows a side view of a heat exchanger 10, in which the central region 13 and the second header pipe 15 are visible in the second end region 12. Two discharge means 20, namely a first discharge means 21 and a second discharge means 22, are arranged laterally on the second header pipe 15. These are designed as grooves 23 with an angle of inclination 24 to a longitudinal direction 52 of the header pipe, which corresponds to the longitudinal direction 50 of the heat exchanger.

[0027] Both discharge means 20 have two ends and extend linearly between the ends. The ends in a central region in the longitudinal direction 50 of the heat exchanger 10 are arranged higher than the other ends. The condensate is thus transported outward in the longitudinal direction 50 toward outlet openings 33 of an underbody panel 32, into which the second collecting pipe 15 is arranged or inserted. In particular, each discharge means 20 is assigned its own outlet opening 33, so that condensate is drained away and brought directly to an outlet opening 33.

[0028] In Fig. 3 is a further heat exchanger 10 in a lateral view according to Fig. 2, where the discharge means are analogous to Fig. 2 are formed: In the embodiment according to Fig. 3, the discharge means protrude directly into the outlet openings in the underbody panel 32. For this purpose, the discharge means can have a bend, as in Fig. 3 shown.

[0029] In Fig. Figure 4 shows a side view of another heat exchanger 10, in which a plurality of discharge means 20, specifically in the form of rods 25, are arranged on the second header pipe 15. These extend in the vertical direction 51 of the heat exchanger 10 and are thus perpendicular to the longitudinal direction 52 of the second header pipe. The discharge means 20 are again each assigned to an outlet opening 33 in the underbody paneling 32. They do not extend beyond the second header pipe 15 in the vertical direction 51 of the heat exchanger 10 toward the first end region 11.

[0030] In Fig. Figure 5 shows a plan view of the lower portion of another heat exchanger 10. The second manifold 15 and a housing 30 are clearly visible. The housing 30 is an underbody panel 32 into which the second manifold 15 is enclosed, primarily by means of a frame 35. The second manifold 15 is enclosed in such a way that a gap 36 is created between the second manifold 15 and the housing 30, so that the frame 35 acts as a housing section 31 as a discharge means 20.

[0031] This is clearer in the sectional view of the Fig. 6, which shows the second collecting pipe 15 and the housing section 31. The housing section 31 extends in a funnel shape toward the second collecting pipe 15 in order to specifically collect water in this area.

[0032] In Fig.Figure 7 shows a process diagram of a method 100 for operating a heat exchanger, in particular a method 100 for operating a heat pump comprising a corresponding heat exchanger. In particular, a defrost cycle is performed 101, and condensate, which subsequently returns to the liquid state, is drained 102 by means of a draining means. List of reference symbols 10 heat exchangers 11 first end area 12 second end area 13 middle range 14 first collecting pipe 15 second collecting pipe 20 diverting agents 21 first diverting agent 22 second discharge agent 23 Gutter 24 tilt angles 25 bars 30 housings 31 Housing section 32 Underbody paneling 33 Outlet opening 35 frame 36 gap 40 Refrigerant flow 50 Longitudinal direction of the heat exchanger 51 Height direction of the heat exchanger 52 Longitudinal direction of the collecting pipe 100 Methods for operating a heat exchanger 101 Performing a defrost cycle 102 Drainage of condensate using a drainage agent QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2020 / 058585 A1

[0002] DE 10 2022 202 503 A1

[0003] DE 10 2020 200 079 A1

[0004]

Claims

[1] Heat exchanger (10) of a motor vehicle with a first collecting pipe (14) in a first end region (11) and a second collecting pipe (15) in a second end region (12), characterized by , that the heat exchanger (10) comprises at least one discharge means (20) on a collecting pipe for discharging condensate on the heat exchanger (10). [2] Heat exchanger (10) according to claim 1, characterized by that the at least one discharge means (20) is arranged laterally on the collecting pipe. [3] Heat exchanger (10) according to one of claims 1 or 2, characterized by that the at least one discharge means (20) is a channel (23). [4] Heat exchanger (10) according to one of the preceding claims, characterized by that the discharge means (20) is arranged inclined compared to a longitudinal direction (52) of the collecting pipe. [5] Heat exchanger (10) according to claim 4, characterized bythat the discharge means (20) forms an angle of inclination (24) of between 1° and 20° with the longitudinal direction (52) of the collecting pipe. [6] Heat exchanger (10) according to one of the preceding claims, characterized by that the at least one discharge means (20) is arranged perpendicular to a longitudinal direction (52) of the collecting pipe. [7] Heat exchanger (10) according to one of the preceding claims, characterized by that each discharge means (20) is assigned to an outlet opening (33) in an underbody of the vehicle. [8] Heat exchanger (10) according to one of the preceding claims, characterized by , that the heat exchanger (10) comprises a housing (30), wherein the discharge means (20) is designed as a housing section (31), wherein the housing section (31) is arranged at a distance from the collecting pipe. [9] Vehicle comprising a heat exchanger (10) according to one of claims 1 to 8. [10] Method (100) for operating a heat exchanger (10) according to one of claims 1 to 8, characterized by that the method (100) comprises carrying out (101) a defrost cycle and draining (102) condensate water with the aid of the at least one draining means (20) on a collecting pipe of the heat exchanger (10).

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