Patent Publication Number: US-2013248151-A1

Title: Apparatus for cooling a heat source of a motor vehicle

Description:
The invention relates to an apparatus for cooling a heat source of a motor vehicle. 
     WO 2009/146876 A1 discloses an apparatus for cooling a vehicle battery. The apparatus has a heat sink, wherein the heat sink is designed as at least one extruded profile. A collector for collecting or distributing the cooling fluid is arranged at each of the ends of the at least one extruded profile. 
     It is the object of the invention to make available an apparatus for cooling a heat source of a motor vehicle which comprises fewer individual components and requires less installation space overall. 
     This object is achieved by means of an apparatus having the features of claim  1 . Advantageous embodiments form the subject matter of the dependent claims. 
     As a basic concept of the invention, an apparatus for cooling a heat source of a motor vehicle has a hollow heat sink, an inlet for introducing a cooling fluid, an outlet for discharging a cooling fluid, a first collecting region for collecting the cooling fluid introduced, a second collecting region for collecting the cooling fluid to be discharged, and an insert part for guiding the cooling fluid from the first to the second collecting region. According to the invention, provision is made for both the insert part and the at least first and second collecting regions to be arranged within the heat sink. 
     By integrating the collector function into the heat sink, it is possible to reduce the installation space requirement. As a consequence, it is furthermore possible to reduce the weight of the heat sink. 
     According to the invention, the insert part is preferably designed as a separate part. 
     According to the invention, the feature “heat source” is taken, for example, to include a vehicle battery, in particular a lithium-ion battery, which releases lost heat to the heat sink. 
     In a preferred embodiment, the heat sink is of tubular design, in particular is designed as a flat tube with a first and a second end. Flat tubes of this kind can be produced easily and at low cost. Moreover, the “sheet-like” side thereof forms a flat surface for the attachment of a heat source to the heat sink. The flat tube is preferably produced from metal, in particular from aluminum or an aluminum alloy. As an alternative, however, it is also possible to form the flat tube as an extruded profile made of plastic. 
     The flat tube is closed fluidtightly at both of the ends thereof. A dedicated closing element made, for example, of plastic, which is connected materially, in particular adhesively bonded, to the heat sink is a preferred and suitable option for this purpose. 
     In another preferred embodiment, the insert part is designed as a corrugated rib. By means of the corrugated rib, individual subducts are formed, enabling the cooling fluid to be passed from the first to the second collecting space. The corrugated rib is preferably made of metal, in particular aluminum, and is connected materially, in particular soldered, to the flat tube or heat sink. The individual subducts are preferably not connected to one another fluidically. 
     In another preferred embodiment, the longitudinal extent of the insert part is smaller than the longitudinal extent of the heat sink or flat tube, at least in a certain region or regions, i.e. the extent from the first to the second end. The two collecting regions are thus formed by the shortened insert part. 
     In another preferred embodiment, a plurality of insert parts is provided between the first and second collecting spaces. For example, provision can be made for the cooling fluid to flow from a first collecting space into an intermediate collecting space and then into the second collecting space. In this arrangement, a first insert part is arranged between the first collecting space and the intermediate collecting space, and a second insert part is arranged between the intermediate collecting space and the second collecting space. By means of an embodiment of this kind, the ducting can be matched to the width of the heat sink, in particular to the width of the flat tube. 
     By means of a suitable insert part or by means of suitable insert parts, different types of flow through the heat sink are conceivable in preferred detailed variants (e.g. flow in an “I-flow” pattern (no deflection of the cooling fluid), flow in a “U-flow” pattern (one deflection of the cooling fluid) or flow in an “S-flow” pattern (two deflections of the cooling fluid)). More than two deflections of the cooling fluid within the heat sink are also conceivable. 
     In a preferred embodiment, the cooling fluid is a coolant of a cooling circuit. As an alternative or in addition, the fluid can also be a refrigerant of a refrigerating circuit, wherein the heat sink is designed as an evaporator for the refrigerant. In the text which follows, a coolant is understood to be a heat transfer fluid, in particular but not necessarily in the liquid phase, which undergoes substantially no phase change as it flows through the heat sink. In the case of a refrigerant in the sense according to the invention, evaporation of the refrigerant generally takes place in the heat sink, the heat sink being part of a refrigerating circuit comprising a compressor, a gas cooler/condenser and an expansion member. In particular, the refrigerating circuit can comprise an air conditioning system of the vehicle. 
     It goes without saying that the features mentioned above and those which will be explained below can be used not only in the respectively indicated combination but also in other combinations or in isolation without exceeding the scope of the present invention. 
     Further important features of the present invention will emerge from the following detailed description in conjunction with the claims and the drawings. 
    
    
     
       In the text which follows, a preferred illustrative embodiment of an apparatus according to the invention for cooling a heat source of a motor vehicle is described and explained in greater detail with reference to the attached drawing. 
       In the drawing: 
         FIG. 1  shows a detail of an apparatus according to the invention for cooling a heat source of a motor vehicle; 
     
    
    
       FIG. 1  shows a detail of an apparatus  1  according to the invention for cooling a heat source of a motor vehicle. A vehicle battery, in particular a lithium-ion battery, could be provided as a heat source (not shown), for example. 
     The illustration according to  FIG. 1  shows a heat sink  2 , on the upper side  2   a  of which a multiplicity of battery cells of a lithium-ion battery which require cooling are arranged. The battery is held on the heat sink by means of straps or the like, for example, giving good heat-conducting contact between the battery and the heat sink. In addition, heat-conducting foils or similar could be provided between the heat sink and the battery in order to further improve heat conduction. 
     According to the embodiment under consideration, the heat sink  2  is designed as a flat tube made of metal. The flat tube has an inlet  3  for introducing a cooling fluid and an outlet for discharging (not shown) a cooling fluid. The flat tube is closed fluidtightly at both of the ends  6  thereof by a closing element  7 . 
     A first collecting space  4  for collecting and distributing the cooling fluid is arranged on the outflow side of the inlet  3 , while a second collecting space (not shown) is arranged on the inflow side of the outlet. According to the invention, an insert part  5  designed as a corrugated rib is provided between the first and second collecting spaces. In this case, the corrugated rib is arranged in such a way that individual subducts  5   a  are formed by the troughs of the corrugated rib, through which subducts the cooling fluid flows from a first collecting space  4  to a second collecting space. 
     According to the invention, the first and second collecting spaces and the insert part  5  designed as a corrugated rib are thus arranged within the heat sink  2 . The insert part  5  is furthermore of “shorter” design than the flat tube. According to the invention, the shortened form of the insert part is used to form the two collecting spaces for collecting and distributing the cooling fluid. 
     As a person skilled in the art can easily see from  FIG. 1 , the cross section in the collecting space  4  is chosen in such a way that the flow is slightly accelerated. For this purpose, the collecting space tapers in cross section upstream in accordance with the outflows into the individual subducts  5   a.  By means of a triangular configuration of this kind of the collecting space, improved uniformity of distribution of the cooling fluid is ensured.