Evaporator, in Particular for an Air-Conditioning System of a Motor Vehicle

Abstract

The invention relates to an evaporator (1), in particular for an air-conditioning system of a motor vehicle, comprising flow channels for a coolant and ribs which can be impinged upon by air and which are arranged on the outside of the flow channels. According to the invention, at least one cooling element (5) which can be cross-flown by a coolant (5) is connected in a thermally conductive manner to the evaporator (1) and is connected to a secondary circuit (6) which acts as a cooler for the consumers, in particular electronic components (8).

Description

BACKGROUND OF THE INVENTION

The invention relates to an evaporator, especially for an air-conditioning system of a motor vehicle.

Evaporators for motor vehicle air-conditioning systems are known in various constructions as mechanically joined round tube systems and also perforated flat tube, plate, or tray heat exchangers. A perforated, double-row flat-tube evaporator is known through DE 198 26 881 A1 by the applicant, wherein corrugated fins are arranged between the flat tubes which are impinged upon by surrounding air that is cooled in the evaporator and fed into the inner compartment of the vehicle. The evaporator is embedded in a refrigerant circuit of the air-conditioning system and carries a flow of refrigerant (R134a). A perforated tray evaporator is known, for example, from DE 198 14 050, wherein corrugated fins that can be impinged upon by surrounding air are also arranged here between the trays. The evaporator is arranged in an air-conditioning device within an air channel.

There is a plurality of electronic components or units in the motor vehicle that generate heat and therefore must be cooled. Here, surrounding air is usually used as the coolant. In DE 89 14 525 U1 by the applicant, an electronic component is cooled by the air flow drawn in by a fan, wherein the cover of the fan is formed as a cooling body. Another possibility for cooling electronic components is known by the applicant through DE 37 03 873 A1, wherein a cooling body is made from a base body with a fin package connected with a material fit, upon which cooling air impinges. The cooling body is connected to the electronic unit with its base body in a heat-conductive way.

Another cooling device, for cooling electronic components through convection, is proposed by the applicant in DE 198 06 978 A1, wherein the cooling body has corrugated fins that are impinged upon by a cooling air flow.

For increasing the cooling effect, a cooling device is proposed in DE 41 31 739 A1 having a hollow space that carries a flow of cooling fluid for heat transfer. The hollow space has turbulence inserts for increasing the heat transfer and is connected to the electronic unit via a base plate in a heat conductive way.

A similar cooling device for electronic components is proposed by the applicant in DE 199 11 205 A1, wherein a hollow space carries a flow of a liquid coolant that is removed from and fed back to a coolant radiator of a motor vehicle cooling circuit.

Finally, in DE 199 11 204 A1 by the applicant, a cooling device for electronic components is proposed wherein the components are connected directly to a coolant radiator of a motor vehicle in a heat-conductive connection, for example, arranged on the side parts or the coolant box of the radiator. The heat to be discharged thus flows directly into the coolant of the radiator via heat conduction.

A disadvantage in the known proposals mentioned above is that the heat that can be discharged is limited by the existing temperature of the coolant, whether it is an air flow or a liquid flow. In particular, at high outside temperatures, both the cooling air flow and also a coolant flow removed from the coolant radiator have a relatively high temperature. Thus, the cooling power is also limited.

The task of the present invention is to create a device for cooling loads generating heat, especially in a motor vehicle and preferably for electronic components, which allows a higher cooling power.

This task is solved as described and claimed herein. According to the invention, an evaporator, especially in a motor vehicle air-conditioning system, is used for cooling purposes, and at least one cooling element is implemented in the evaporator that can carry a coolant flow. The cooling element is located in heat-conductive contact with the evaporator, especially with its flow channels guiding the refrigerant, so that the heat absorbed by the coolant can be released to the refrigerant, which has a relatively low temperature in the evaporator. The cooling element is connected to a cooling circuit, a so-called secondary circuit, guiding the coolant that absorbs heat from loads to be cooled and transports it to the evaporator, which acts as a heat sink. The evaporator itself is not changed in its operation, thus there is also no intervention in the refrigerant circuit of the air-conditioning system. In principle, any type of evaporator is possible as a heat sink for the cooling according to the invention, but preferably flat tube, plate, or tray evaporators are used that offer smooth surfaces for connection to the cooling element according to the invention. Soldering the cooling element to parts of the evaporator, whereby an especially good heat transfer is achieved, is advantageous. Also, the refrigerant flowing through the evaporator is arbitrary, i.e., either a conventional refrigerant, such as R134a, or an alternative refrigerant, such as R744 (carbon dioxide) can be used. CO₂ evaporators also offer good possibilities for integrating at least one cooling element according to the invention.

In one advantageous construction of the invention, the cooling element or elements integrated into the evaporator can carry a flow of coolant, preferably a water-Glysantin mixture, and are connected to a separate cooling circuit, a secondary circuit. Individual loads generating heat, e.g., electronic components, are assigned to this secondary circuit, with the coolant of the secondary circuit being led past these components. Here, cooling bodies known from the state of the art mentioned above can be used. The cooling element according to the invention is preferably constructed as a rectangular tube, i.e., box-shaped, wherein it preferably takes up the space between two adjacent flat tubes, plates, or trays. This space is taken up by a corrugated fin in standard evaporators. The cooling element thus takes the place of the corrugated fin and fills its space, wherein—as mentioned—the heat conduction can be increased considerably through soldering. Alternatively, the cooling element can also be arranged between two corrugated fins or between a flat tube (tray or plate) and one corrugated fin, and soldered to these parts.

In another advantageous construction of the invention, the cooling element can carry one or more flows, i.e., it can carry a flow of coolant in two or more directions with reversal, whereby the cooling power can be influenced in this way. For increasing the heat transfer, turbulence inserts can be provided that can also be soldered to the walls of the cooling element. The cooling element is connected on the coolant side to the secondary circuit via an inlet and outlet port, wherein the coolant can be circulated by a pump.

In another construction, the evaporator has at least one cooling element that is connected to at least one outer flat tube with a material fit, especially through soldering, welding, adhesion, etc., and/or especially with a positive fit through clips, screws, etc. In this way, a side part, especially two side parts, of the evaporator are advantageously eliminated and costs are reduced. Advantageously, the width of the cooling element can be selected arbitrarily according to the required cooling power and is not dependent on the modular dimensions of tubes, especially flat tubes, and/or fins, especially corrugated fins.

In another construction, the evaporator has at least one first cooling element and at least one second cooling element which can carry a flow, especially advantageously in series.

In another construction, the evaporator has at least one first cooling element and at least one second cooling element which can carry a flow in parallel.

In another advantageous construction, at least one cooling element replaces at least one side part of the evaporator and delimits, in particular, the tube block. Therefore, in an especially advantageous way, at least one part, especially two parts, are eliminated, and thus the costs are advantageously reduced. The cooling element is flush with at least one of the collecting tanks in another advantageous construction and is connected, in particular, to at least one of the collecting tanks with a material fit, especially through soldering, welding, adhesion, etc. In another advantageous construction, the cooling element does not terminate flush with at least one collecting tank and is not connected to at least one collecting tank.

In another advantageous construction, at least one cooling element of the evaporator has a width that is independent of at least one modular dimension of at least one tube, especially a flat tube, and/or at least one fin, especially a corrugated fin.

In another advantageous construction, at least one cooling element of the evaporator has a width that is dependent on at least one modular dimension of at least one tube, especially a flat tube, and/or at least one fin, especially a corrugated fin.

According to an advantageous improvement of the invention, a cooling device with a secondary circuit is provided that can be alternatively connected to the engine cooling circuit of a motor vehicle or to a heating body arranged in the engine cooling circuit. In this way, the advantage is achieved that the secondary cooling circuit is redundant in case of a failed air-conditioning system. The coolant of the secondary circuit is then cooled in the heating body, through which there is a flow of air. The cooling of the electronics can thus be maintained. In an advantageous construction, the heating body is connected or disconnected by means of thermostatic valves or electrically controllable multi-port valves. In another advantageous construction, a controllable short circuit is provided between the feed and return line of the secondary circuit, whereby condensation can be prevented.

In another advantageous construction of the invention, an additional heat exchanger, which is connected to a secondary circuit for cooling loads, especially electronic components, is connected downstream on the air side of the evaporator of a motor vehicle air conditioning system. The additional heat exchanger, preferably a serpentine heat exchanger, is cooled by the cold air leaving the evaporator and thus acts as a heat sink for the secondary cooling circuit. Advantageously, the additional heat exchanger, which has a relatively small depth in the direction of air flow, can be installed between the evaporator and heating body of a conventional air-conditioning system, without requiring additional installation space.

Embodiments of the invention are shown in the drawing and are defined in more detail below.

BRIEF SUMMARY

An evaporator (1), in particular for an air-conditioning system of a motor vehicle, comprising flow channels for a coolant and ribs which can be impinged upon by air and which are arranged on the outside of the flow channels. According to the invention, at least one cooling element (5) which can be cross-flown by a coolant (5) is connected in a thermally conductive manner to the evaporator (1) and is connected to a secondary circuit (6) which acts as a cooler for the consumers, in particular electronic components (8).

One object of the present disclosure is to describe an improved evaporator for the air-conditioning system of a motor vehicle.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a refrigerant circuit with an evaporator according to the invention with a secondary circuit.

FIGS. 2, 2a illustrate a flat tube evaporator according to the invention with integrated cooling element.

FIGS. 3, 3a illustrate a flat tube evaporator with two integrated cooling elements.

FIGS. 4, 4a illustrate an evaporator for an alternative refrigerant (CO₂) with integrated cooling element.

FIGS. 5, 5a, 5b, 5c illustrate a cooling element that can carry double flow.

FIGS. 6, 6a illustrate a cooling element that can carry single flow.

FIG. 7 a illustrates a cooling element that can carry double flow.

FIGS. 7 b, c, d illustrate a cooling element that can carry single flow.

FIGS. 8 a, 8b, 8c, 8d, 8e illustrate various arrangements of cooling elements in the evaporator.

FIG. 9 a illustrates a front view of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block.

FIG. 9 b illustrates an isometric representation of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block.

FIG. 9 c illustrates a cooling element that can carry double flow.

FIG. 10 a illustrates a front view of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block.

FIG. 10 b illustrates an isometric representation of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block.

FIG. 10 c illustrates an isometric representation of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block.

FIG. 10 d illustrates a cooling element that can carry single flow.

FIG. 11 a illustrates a rear view of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block.

FIG. 11 b illustrates an isometric representation of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block.

FIG. 11 c illustrates a cooling element that can carry single flow.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the illustrated device and its use, and such further applications of the principles of the disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.

FIG. 1 shows a double-row flat tube evaporator 1, which is connected on the refrigerant side to a refrigerant circuit 2 of a not-shown motor vehicle air-conditioning system. In addition to the evaporator 1, there is a condenser 3 and a compressor in the refrigerant circuit. The evaporator 1 corresponds in its construction essentially to the state of the art mentioned above (DE 198 26 881 A1 by the applicant) and carries a flow of conventional refrigerant (R134a). The evaporator 1 thus has a block 1a consisting of non-designated flat tubes and corrugated fins, as well as top and bottom collecting tanks 1b, 1c. In the center region of the block 1a, a cooling element 5 is implemented in the evaporator 1 that is connected to a secondary circuit 6. In the secondary circuit 6, a cooling body 7, which is connected in a heat conductive way to an electronic component 8 to be cooled, is arranged as an example of a load. The cooling element 5, secondary circuit 6, and cooling body 7 carry a flow of coolant, preferably a liquid coolant, a water-Glysantin mixture, wherein the coolant can be circulated by a not-shown pump. In the secondary circuit 6, which thus acts as a cooling circuit, other not-shown loads can be arranged that are also cooled by the coolant flow. The cooling element 5 outputs the heat absorbed by the coolant to the evaporator or the refrigerant, i.e., the evaporator 1 acts as a heat sink for the cooling circuit 6. The primary function of the evaporator, to cool air for the interior of the vehicle, is not negatively affected by the connection of the secondary circuit 6. There is also no intervention into the refrigerant circuit 2.

FIGS. 2 and 2 a show a flat tube evaporator 10 in a view from the front as well as in a 3D representation. The evaporator 10 has flat tubes 10a, between which there are corrugated fins 10b that are impinged upon by the surrounding air. In the middle region of the evaporator 10 between two flat tubes 10a there is a cooling element 11 that is heat conductively connected, preferably through soldering, to the flat tubes 10a. The cooling element 11 has an inlet port 11a and an outlet port 11b for connecting to the secondary or coolant circuit (cf. secondary circuit 6 in FIG. 1), not shown here, in its bottom region (in the drawing). The flat tube evaporator 10 has a refrigerant connection flange 10c which is connected on one side to a not-shown refrigerant circuit of the motor vehicle air-conditioning system, and on the other side to the evaporator 10 or its collecting tanks via connection tubes 10d, 10e. The evaporator 10 carries a flow of air in the direction of the arrow L, which is cooled in the evaporator and is fed to a not-shown passenger compartment of the motor vehicle.

FIGS. 3 and 3 a show another embodiment of the invention in the form of a flat tube evaporator 20, in a view from the front and in an oblique representation. The construction of the flat tube evaporator 20 corresponds essentially to the construction of the evaporator according to FIGS. 2 and 2a with the difference that here two cooling elements 21, 22 are integrated into the evaporator block, i.e., each between two adjacent flat tubes. The cooling elements 21, 22 correspond in their construction to the cooling element 11 according to FIGS. 2, 2a, i.e., they also have connection ports 21a, 21b and also 22a, 22b. Both cooling elements 21, 22 are also connected to the secondary circuit, not shown here. By multiplying the number of cooling elements, the cooling capacity of the secondary circuit is increased accordingly—but at the cost of the secondary-side heat exchange surface area (corrugated fins) of the evaporator.

FIGS. 4 and 4 a show another embodiment of the invention in the form of an evaporator 30, in a view from the front and in a 3D representation. The evaporator 30 corresponds essentially also to the state of the art and is operated with an alternative refrigerant, CO₂ or R744, which means a pressure-tight construction for the individual evaporator components. The evaporator 30 has U-shaped or serpentine-shaped flat tubes 31 (preferably multiple-chamber tubes), between which are arranged corrugated fins, not shown here. The evaporator 30 is connected via connection tubes 32, 33 to a not-shown CO₂ refrigerant circuit of a motor vehicle air-conditioning system, wherein the connection tubes 32, 33 each transition into a distributor or collection tube 32′, 33′. The distribution of the refrigerant is performed in a collecting tank 34, which is shown in FIG. 4a in an exploded view. This evaporator type is also known from the state of the art, for example, DE 102 60 030 A1 by the applicant. Other constructions for evaporators operated with CO₂ are known through DE 100 25 362 A1. A cooling element 35 is integrated in the evaporator 30, approximately in the middle region, and arranged between two adjacent flat tubes 31, i.e., preferably soldered together with the adjacent flat tubes. The cooling element 35 has connection ports 35a, 35b in its lower region for connection to the secondary circuit mentioned above that serves to cool loads generating heat.

FIGS. 5, 5a, 5b, 5c show as an individual part a cooling element 60 that corresponds to the cooling elements 5, 11, 21, 22, 35 mentioned above. Just like the evaporator mentioned above, the cooling element 60 is also composed of aluminum materials and can thus be soldered to the evaporator. The cooling element 60 is formed as a rectangular tube 61 in which a holder frame 62 is inserted that closes the tube 61 on the end. The two connection ports 60a, 60b are arranged on the narrow side of the rectangular tube 60. FIG. 5a shows the interior of the rectangular tube 60, wherein an angled separating wall 63 is arranged between the coolant inlet 60a and the coolant outlet 60b. Thus there is an approximately U-shaped flow channel between the two connection ports 60a, 60b, i.e., the cooling element 60 carries a double flow. Flow arrows E for the inflow of the coolant and U for the reversal of the coolant are shown in FIG. 5c. The U-shaped flow channel is filled with a turbulence plate 64, which is shown in cross section in FIG. 5c. It can be soldered to the rectangular tube 60. There are free spaces 65, 66, i.e., not occupied by the turbulence plate, in the region of the inlet and outlet ports 60a, 60b for the distribution or collection of the coolant. The coolant is preferably a fluid heat carrier, especially a water-Glysantin mixture.

FIGS. 6 and 6 a show another embodiment of a cooling element 70 that can carry a single flow. The cooling element 70 is also constructed as a rectangular tube 71 and has an inlet port 70a on the narrow side in its bottom region and an outlet port 70b on the same side in its upper region for connection to the secondary circuit, not shown here. In FIG. 6a, the interior, i.e., the flow path of the coolant through the cooling element 70, is shown by means of an inlet-side flow arrow E and an outlet-side flow arrow A. Between the inlet and outlet ports 70a, 70b there is a turbulence plate 72 that leaves spaces 73, 74 free for the distribution and collection of the coolant within the cooling element 70. Through the turbulence plate 72, the heat transfer from the coolant to the rectangular tube and thus also to the refrigerant is improved. Compared with the embodiment according to FIGS. 5 to 5c with a double flow, a smaller coolant-side pressure drop, but also a smaller cooling output is produced for the single flow. Instead of the turbulence plate 72, other means increasing the heat transfer are also possible, e.g., simple internal ribbing.

FIGS. 7 a, 7b, 7c, 7d show additional embodiments for a cooling element. Identical features are designated with the same reference symbols as in the preceding figures.

FIG. 7 a corresponds to FIG. 5b.

FIG. 7 b shows another embodiment for a cooling element 90 that can carry a single flow. The cooling element 90 is also constructed as a rectangular tube and has an inlet port 90a on the narrow side in its bottom region and an outlet port 90b in its upper region for connecting to the secondary circuit, not shown here. The interior, i.e., the flow path of the coolant through the cooling element 90, is shown by inlet-side flow arrows E and outlet-side flow arrows A. Between the inlet and outlet ports 90a, 90b there is a turbulence plate 92 that leaves spaces free for the distribution and collection of the coolant within the cooling element 90. Through the turbulence plate 92, the heat transfer from the coolant to the rectangular tube and thus also to the refrigerant is improved. In comparison with FIG. 5b, the inlet and outlet ports 90a, 90b are arranged on the opposite side.

FIG. 7 c corresponds to FIG. 6a.

FIG. 7 d shows another embodiment for a cooling element 100 that can carry a single flow. The cooling element 100 is also constructed as a rectangular tube and has an inlet port 100a on the narrow side in its lower region and, in contrast to FIG. 6 and FIG. 7c, has an outlet port 100b in its upper region on the opposite side of the cooling element 100 for connection to the secondary circuit, not shown here.

FIGS. 8 a, 8b, 8c, 8d, 8e show various possibilities for the arrangement or integration of cooling elements in an evaporator. Identical features are designated with the same reference symbols as in the preceding figures.

In FIG. 8a, a cooling element 80 is arranged between adjacent flat tubes 81 of a double-flow flat tube evaporator. The walls of the cooling element 80 contact the flat tubes 81 directly and are preferably soldered to these tubes, which produces an excellent heat transfer. The heat released by the coolant in the cooling element 80 flows directly into the flat tubes 81 in which the refrigerant is flowing. Corrugated fins 82, which are also soldered to the flat tubes 81, are arranged on the sides of the flat tubes 81 facing away from the cooling element 80.

FIG. 8 b shows another embodiment, two cooling elements 80 that are each arranged between adjacent flat tubes 81. The two cooling elements 80 release their heat on one side to the middle, and on the other side to the two outer, flat tubes 81.

FIG. 8 c shows another asymmetric arrangement, wherein the cooling element 80 contacts on one side, i.e., with one broad side, the flat tubes 81 and on the other side, i.e., with the other broad side, corrugated fins 82. All of the parts are soldered to each other, so that the heat is released from the cooling element 80 on one side into the flat tubes 81 and on the other side via the corrugated fins 82 to the air flowing above, shown by arrows L.

FIG. 8 d shows another embodiment, wherein the cooling element 80 is arranged directly between adjacent corrugated fins 82 that are in heat-conductive contact with flat tubes 81 on the other side. The heat generated by the cooling element 80 flows via heat conduction directly into the corrugated fins 82 and is released on both sides to the surrounding air flowing over the corrugated fins 82.

FIG. 8 e shows another embodiment. The flat tube evaporator has at least one flat tube 81, especially several flat tubes 81, as well as at least one outer flat tube 83, especially two outer flat tubes. The outer flat tube 83 has a first inner side 84, which is arranged adjacent to a corrugated fin 82, or in another, not-shown embodiment adjacent to a flat tube 81. Next to the first inner side 84, the outer flat tube 83 has an essentially parallel second outer side 85. The second outer side 85 of the outer flat tube 83 is connected with a material fit to the cooling element 80, especially through soldering, welding, adhesion, etc., whereby an excellent heat transfer is produced. The heat released from the coolant in the cooling element 80 flows directly into the outer flat tube 83 in which the refrigerant flows. Especially advantageous is to replace at least one side part, which delimits, in particular, the tube block to the outside, by the cooling element 80. In particular, two side parts, which each delimit the tube block to the outside, are replaced by two cooling elements. In this way, at least one side part is eliminated and the costs are reduced.

In another embodiment that is not shown, the second outer side 85 of the outer flat tube 83 is connected to the cooling element 80 with a positive fit, especially with a clip connection, screw connection, etc., or with a positive and material fit. In the shown construction, a cooling element 80 is connected to at least one second outer side 85 of an outer flat tube 83.

In another embodiment, the flat tube evaporator has two outer flat tubes 83, one on each outer side. Each cooling element 80 is connected to an outer flat tube 83, especially with a material fit through soldering, welding, adhesion, etc., so that the flat tube evaporator has a total of two cooling elements 80.

In another not-shown embodiment, the flat tube evaporator has more than two cooling elements. One cooling element 80 is connected to an outer flat tube, at least one other cooling element 80, especially several other cooling elements 80, [these] are arranged between two flat tubes 81 in a first variant or between two corrugated fins 82 in a second variant or between a flat tube and a corrugated fin in a third variant, and connected to these parts or arranged as a combination of the three variants.

FIG. 9 a shows the front view of a flat tube evaporator with cooling elements arranged on the evaporator block on the outside. FIG. 9b shows the associated isometric representation of a flat tube evaporator with cooling elements arranged on the evaporator block on the outside. FIG. 9c shows the associated cooling element. Identical features are provided with the same reference symbols as in the preceding figures.

FIGS. 9 a, 9b show a flat tube evaporator 270, which is connected on the refrigerant side to a refrigerant circuit 300 of a not-shown motor vehicle air-conditioning system. In the refrigerant circuit, a condenser 280 and a compressor 290 are arranged next to the evaporator 270. The evaporator 270 corresponds in its construction essentially to the state of the art (DE 198 26 881 A1 by the applicant) mentioned above and carries a flow of a conventional refrigerant (R134a). In addition, in another construction it is operated with an alternative refrigerant CO₂ or R744. The evaporator 270 thus has flat tubes 230 and outer flat tubes 220 on undesignated corrugated fins, as well as upper and lower collecting tanks 230 and 320. A block 370 has the flat tube 230, two outer flat tubes 220, and also undesignated corrugated fins. The block 370 is delimited on two opposing sides by a cooling element 210. At least one cooling element 210, in particular each cooling element 210, is connected to a secondary circuit 380. The secondary circuit 380 has at least one feed line 350 and at least one return line 360. The secondary circuit has at least one load with at least one cooling body 330, which is heat-conductively connected to at least one electronic component 340 to be cooled. The return line 360 is arranged upstream of the cooling body 330 and is connected to at least one outlet connection 260 of the cooling element 210. The feed line is arranged downstream of the cooling body 330 and is connected to at least one inlet connection 250 of the cooling element 210. The cooling element 210, secondary circuit 380, and cooling body 330 carry a coolant, preferably a fluid coolant, especially a water-Glysantin mixture, wherein the coolant can be circulated by a not-shown pump. Other not-shown loads can be arranged, which are likewise cooled by the coolant flow, in the secondary circuit 380, which thus acts as a cooling circuit. The one or more cooling elements 210 transfer the heat absorbed by the coolant to the one or more outer flat tubes 220 and thus to the evaporator 270 and the refrigerant, i.e., the evaporator 270 acts as a heat sink for the cooling circuit 380. The one or more cooling elements 210 are arranged adjacent and especially parallel to the outer flat tube 220 of the evaporator 270, and in particular are connected to the outer side of the flat tube in a conductive, especially a heat-conductive way and with a material fit, especially through soldering, welding, adhesion, etc., and/or with a positive fit, especially through clips, screws, etc. According to the required cooling power, only one cooling element 210 can be connected to an outer flat tube 220. For a greater required cooling power, a cooling element is connected to each of the two outer flat tubes 220, so that at least two cooling elements 210 are connected to the evaporator 270. In comparison to the construction in FIGS. 1, 3, 4, the width 390 of the cooling element can be designed as larger or smaller according to the required cooling power. In FIGS. 1, 3, 4 the width 390 of the cooling element must be adapted to the modular dimensions of the flat tubes or the corrugated fins. In this embodiment, the width 390 of the cooling element 210 can be steplessly variable. With this embodiment, the number of cooling elements, and the width 390 according to the cooling power required in the secondary circuit 380, can be assembled as in a modular system. The one or more inlet connections 250 and one or more outlet connections 260 are arranged essentially parallel to each other, in the embodiment essentially adjacent to the lower collection tube 320. The cooling element 210 comprises a first outer face 390, a second outer face 400, and also a third outer face 410. In addition, the cooling element has a fourth outer face, which has essentially the size of the first outer face 390 and which is arranged essentially parallel to this face, a fifth outer face, which has essentially the size of the second outer face 400 and which is arranged essentially parallel to this face, and also another sixth outer face, which has essentially the size of the third outer face 410 and which is arranged essentially parallel to this face. In another embodiment, the one or more inlet connections 250 and the one or more outlet connections are arranged on at least the first outer face 390, and/or the second outer face 400 and/or the third outer face 410 and/or the fourth outer face and/or the sixth outer face, wherein the inlet connections 250 and the outlet connections 260 can be arranged on the same outer face of the same cooling element 210 or the inlet connections 250 can be arranged on a different outer face of the same cooling element 210 than the face on which the outlet connections 260 are arranged. FIG. 9c corresponds to FIG. 7a and shows a section through the cooling element 210. Identical elements are here designated with the same reference symbols as in the preceding figures. The cooling element 210, however, can also be formed as shown in FIG. 7b, 7c, or 7d.

FIG. 10 a shows the front view of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block. FIG. 10b shows the isometric representation of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block. FIG. 10c shows the isometric representation of another embodiment of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block. FIG. 10d shows a cooling element that can carry a single flow. Identical features are provided with the same reference symbols as in the preceding figures.

In contrast to FIG. 9a, FIGS. 10a and 10b show a cooling element 510. The inlet connection 550 is arranged in the lower region of the cooling element 510, essentially adjacent to the lower collecting tank 320, and the outlet connection 560 is arranged in the upper region of the cooling element 510, essentially adjacent to the upper collecting tank 310. A second cooling element 520 has an inlet connection 550 in the upper region of the cooling element 520, essentially adjacent to the upper collecting tank 310, and an outlet connection 560 in the lower region of the cooling element 520, essentially adjacent to the lower collecting tank 320. The secondary cooling circuit 680 has a feed line 650 and a return line 660. The coolant flows through the first cooling element 510 and the second cooling element 520 in series. Here, the coolant of the secondary circuit 680 enters into the cooling element 510 on the feed side 650 via the inlet connection 550, flows through this cooling element, and leaves this cooling element 510 via the outlet connection 560. The coolant then flows via a not-shown line to the inlet connection 550 of the second cooling element 520, flows through this cooling element, and emerges from the second cooling element 520 via the outlet connection. However, the reverse direction of flow is also possible.

FIG. 10 c shows another embodiment. Two cooling elements 710 of an evaporator 770 each comprise an inlet connection 750, which is arranged in the lower region of the cooling element 710 essentially adjacent to the lower collecting tank 320, and an outlet connection 760, which is arranged in the upper region of the cooling element 710 essentially adjacent to the upper collecting tank 310. The secondary cooling circuit 880 has a feed line 850 and a return line 860. The coolant flows through the first cooling element 710 and the second cooling element 710 in parallel. Here, the coolant of the secondary circuit 880 branches at a not-shown position on the feed side 850 and enters the respective cooling element 710 via the inlet connection 750, flows through this cooling element, and leaves the respective cooling element 510 [sic; 710] via the outlet connection 760. The two discharged coolant flows combine at a not-shown position in the return line 860. However, the reverse direction of flow is also possible.

FIG. 10 d corresponds to FIG. 7c and shows a section through the cooling elements 510, 520, 710. Identical elements are here designated with the same reference symbols as in the preceding figures. The cooling elements 510, 520, 710, however, can also be formed as shown in FIG. 7a, 7b, or 7d.

FIG. 11 a shows the rear view of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block. FIG. 11b shows an isometric representation of a flat tube evaporator with cooling elements arranged on the outside on the evaporator block. FIG. 11c shows a cooling element that can carry a single flow. Identical features are provided with the same reference symbols as in the preceding figures.

In contrast to the preceding figures, the cooling element 910 has an inlet connection 950 and an outlet connection 960 on the rear side instead of on the front side. FIG. 11c corresponds to FIG. 10d and shows the cooling element 910.

Other configurations are conceivable, for example, an arrangement of the cooling elements on the collecting tanks.

A cooling device is contemplated as another embodiment of the invention consisting of an evaporator that is arranged in a refrigerant circuit of a not-shown motor vehicle, a secondary circuit, and also a radiator that is arranged in the cooling circuit of a not-shown internal combustion engine of the motor vehicle. Evaporator, refrigerant circuit, and secondary circuit correspond to the embodiment according to FIG. 1 and the subsequent figures. The secondary circuit is used—as described above—for cooling loads generating heat, especially not-shown electronic components, wherein the evaporator is used with at least one cooling element, not shown here, as a heat sink. The secondary circuit has a feed line and a return line and is connected via connection lines to the radiator such that this is connected parallel to the not-shown cooling element arranged on the evaporator. The cooling circuit of the internal combustion engine (engine cooling circuit) and the secondary circuit both have the same coolant. The radiator is connected alternatively, i.e., instead of the cooling element, in the event that the air-conditioning system in the motor vehicle fails, and thus the evaporator is not functional. Activation is realized via not-shown thermostatically or electrically controllable valves in the feed line or return line. The radiator, which is also part of the not-shown air-conditioning system, is impinged upon by air on the secondary side, so that cooling of the coolant and thus of the secondary circuit can be realized. The radiator is thus used as an alternative to the evaporator as a heat sink for the secondary circuit. Advantageously, there can be a short-circuit line between the feed line and return line that can be controlled via a not-shown thermostatic valve and that adjusts the temperature of the return line for the purpose of preventing condensation at a certain temperature.

Also contemplated as another embodiment of the invention, a cooling device has an evaporator and an additional heat exchanger arranged behind the evaporator in the direction of air flow. The evaporator is part of a not-shown motor vehicle air-conditioning system and is connected to a refrigerant circuit. The construction of the evaporator corresponds to the state of the art—here a flat tube evaporator whose flat tubes, not shown, carry a flow of refrigerant of the refrigerant circuit, while a flow of air passes through the similarly not-shown fins between the flat tubes. The air is thus cooled in the evaporator and encounters the additional heat exchanger, which is preferably formed as a serpentine heat exchanger with a flat tube having multiple reversals, after emerging from the evaporator. The serpentine heat exchanger has two connections by means of which it is connected to a secondary circuit that corresponds to the secondary circuits described above and which is used for cooling loads generating heat, especially electronic components in the motor vehicle. The additional heat exchanger is cooled by the air cooled in the evaporator and is thus used as a heat sink for the secondary circuit, wherein the evaporator acts indirectly as a heat sink—via the air. Advantageously, the additional heat exchanger, which has a relatively small depth in the direction of the air flow, is arranged between the evaporator and a heating body that is connected to the cooling circuit of the internal combustion engine. The end face of the additional heat exchanger can correspond approximately to the end face of the evaporator. The volume flow of the coolant in the additional heat exchanger is relatively small—in this respect connecting the individual tubes in succession, e.g., in the form of the serpentine heat exchanger, is advantageous. Thus, a relatively strong cooling effect is also provided. The additional heat exchanger can be connected mechanically or with a material fit (e.g., through soldering) to the evaporator or to the heating body and thus can be integrated into a standard air-conditioning system.

In particular for the case in which a greater throughput of coolant through the additional heat exchanger is provided, it can also prove useful for several tubes to be arranged into groups in which the coolant flows in a uniform direction. The tubes are then connected by a suitable distribution or collection device to the corresponding coolant connection lines, for example, by known collection tubes. In practice, 2, 3, 4, 5, or 6 blocks has proven effective. Such a construction especially enables reduction of the flow resistance of the cooling water.

Obviously, it is also possible—especially in the case of high coolant throughputs—for the coolant to flow in the same direction in all of the tubes of the additional heat exchanger.

While the preferred embodiment of the invention has been illustrated and described in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that all changes and modifications that come within the spirit of the invention are desired to be protected.

Claims

1. An evaporator, especially for an air-conditioning system of a motor vehicle with flow channels for a refrigerant and with fins, arranged outside of the flow channels and that can be impinged upon by air, characterized in that at least one cooling element (5, 11, 21, 210, 510, 520, 710) that can carry a coolant flow is connected in a heat conductive way to the evaporator (1, 10, 20, 270, 570, 770).

2. The evaporator according to claim 1, characterized in that the evaporator is constructed as a flat tube evaporator (10, 20, 30, 270, 570, 770) with flat tubes (10a, 31, 81, 220, 230) and corrugated fins (10b, 82).

3. The evaporator according to claim 1, characterized in that the evaporator is constructed as a plate or tray evaporator.

4. The evaporator according to claim 1, characterized in that the refrigerant is R134a or R152.

5. The evaporator according to claim 1, characterized in that the refrigerant is R744 (carbon dioxide).

6. The evaporator according to claim 1, characterized in that the one or more cooling elements (5, 11, 21, 22, 35, 80) are arranged between two adjacent flat tubes (10a, 81) or trays or plates.

7. The evaporator according to claim 1, characterized in that the one or more cooling elements (5, 11, 21, 22, 35, 80, 210, 510, 520, 710, 910) are connected to at least one flow channel (10a, 31, 81, 220) with a material fit, especially through soldering, welding, adhesion, etc., or especially with a positive fit through clips, screws, etc.

8. The evaporator according to claim 1, characterized in that the cooling element (5, 11, 21, 22, 35, 60, 70, 80) is connected on the coolant side to a separate cooling circuit (secondary circuit 6).

9. The evaporator according to claim 8, characterized in that the secondary circuit (6) is used for cooling loads generating heat, especially electronic components.

10. The evaporator according to claim 1, characterized in that the coolant in the secondary circuit (6) is a mixture of water and Glysantin.

11. The evaporator according to claim 1, characterized in that the one or more cooling elements (5, 11, 21, 22, 35, 60, 70, 80, 210, 510, 520, 710, 910) are constructed as rectangular tubes (61, 71) and are arranged between adjacent flow channels (81).

12. The evaporator according to claim 1, characterized in that the one or more cooling elements (80) contact the flow channels (81) with both broad sides.

13. The evaporator according to claim 1, characterized in that the one or more cooling elements (80) are arranged between a flow channel (81) and a corrugated fin (82).

14. Evaporator according to claim 1, characterized in that the one or more cooling elements (80) are arranged between two adjacent corrugated fins (82).

15. The evaporator according to claim 1, characterized in that the one or more cooling elements (70) can carry a single flow of coolant.

16. The evaporator according to claim 1, characterized in that the cooling element (69) can carry a double flow (with reversal U).

17. The evaporator according to claim 1, characterized in that the one or more cooling elements (60, 70) have an inlet and an outlet port (60a, 60b, 70a, 70b) for the coolant.

18. The evaporator according to claim 1, characterized in that turbulence inserts (64, 72) are arranged in the interior of the cooling element (60, 70).

19. The evaporator according to claim 1, characterized in that the one or more cooling elements (210, 410, 520, 710, 910) are connected to at least one outer flat tube (220) with a material fit, especially through soldering, welding, adhesion, etc., and/or especially with a positive fit through clips, screws, etc.

20. The evaporator according to claim 1, characterized in that at least one first cooling element (510) and at least one second cooling element (520) can carry a flow in series.

21. The evaporator according to claim 1, characterized in that at least one first cooling element (710) and at least one second cooling element (710) can carry a flow in parallel.

22. The evaporator according to claim 1, characterized in that at least one cooling element (210, 510, 520, 710, 910) replaces at least one side part of the evaporator (270, 570, 770) and in particular delimits the tube block (370).

23. The evaporator according to claim 1, characterized in that a width (390) of the one or more cooling elements (210, 510, 520, 710, 910) is independent of at least one modular dimension of at least one tube, especially a flat tube, and/or at least one fin, especially a corrugated fin.

24. The evaporator according to claim 1, characterized in that a width (390) of the one or more cooling elements (210, 510, 520, 710, 910) is dependent on at least one modular dimension of at least one tube, especially a flat tube, and/or at least one fin, especially a corrugated fin.

25. A cooling device for cooling loads generating heat, especially in a motor vehicle, characterized by the heat-conductive connection of at least one cooling element that can carry a coolant flow to an evaporator, especially of a motor vehicle air-conditioning system, and the connection of a secondary circuit that can carry a flow of coolant to the one or more cooling elements according to one of the preceding claims.

26. Use of an evaporator, especially of a motor vehicle air-conditioning system, as a heat sink for cooling of loads generating heat.