TEMPERATURE-CONTROL ELEMENT WITH SORPTION MATERIAL, IN PARTICULAR FOR CONTROLLING THE TEMPERATURE OF A BATTERY CELL UNIT OF A MOTOR VEHICLE

Abstract

The invention provides a temperature-control element (5) with two covering plates (8) which are arranged at a distance from one another and delimit an intermediate space within which a supporting structure (23) is arranged, said supporting structure keeping the covering plates (8) at a distance from one another, wherein a sorption material (7) which makes contact with the covering plates (8) and the supporting structure (23) is additionally accommodated in the intermediate space. A temperature-control element (5) of this kind allows particularly good transfer of thermal energy between the sorption material (7) and the covering plates (8) by way of the supporting structure (23) not only serving to mechanically connect the covering plates (8) and therefore provide structural strength to the temperature-control element (5) but also causing a transfer of thermal energy between the sorption material (7) and the covering plates (8). As a result, a temperature-control element (5) according to the invention is advantageously also suitable for directly controlling the temperature of, for example, one or more battery cells of a battery cell unit, for example of a traction battery of an electrified motor vehicle.

Claims

1. A temperature-control system with a battery cell unit (3) with at least one battery cell (6) and at least one temperature-control element (5) resting against the battery cell (6) with a covering plate (8), wherein the temperature-control element (5) has two covering plates (8) which are arranged at a distance from one another and form an intermediate space, within which a supporting structure (23) is arranged keeping the covering plates (8) at a distance from one another, wherein a sorption material (7) which makes contact with the covering plates (8) and the supporting structure (23) is additionally accommodated in the intermediate space, wherein the intermediate space of the temperature-control element (5) is connected via a control valve (11) to a phase variator (10) such that a process medium in a gaseous state can flow over between the sorption material (7) arranged within the intermediate space of the temperature-control element (5) and the phase variator (10) when the control valve (11) is opened.

2. The temperature-control system according to claim 1, characterized in that the phase variator (10) can be connected to a refrigerant circuit (13) of a refrigerator (12).

3. The temperature-control system according to claim 1, characterized in that the at least one temperature-control element (5) is integrated in a housing (4) surrounding the at least one battery cell (6) and/or is arranged between two battery cells (6).

4. The temperature-control system according to claim 1, characterized in that the covering plates (8) and/or the supporting structure (23) are formed from one or more metals.

5. The temperature-control system according to claim 1, characterized in that the or at least one of the covering plates (8) and/or the supporting structure (23) is/are coated at least partially with the sorption material (7) on the wall surfaces adjacent to the intermediate space.

6. The temperature-control system according to claim 5, characterized in that the coatings delimit one or more flow channels (25).

7. The temperature-control system according to claim 1, characterized in that the supporting structure (23) comprises a corrugated sheet metal structure and/or a foam structure and/or a nonwoven fabric structure and/or projections (27) formed by at least one of the covering plates (8).

8. The temperature-control system according to claim 1, characterized in that the supporting structure (23) comprises a corrugated sheet metal structure forming a plurality of channels (24) extending along a longitudinal extension of the sheet metal structure and running in parallel to one another.

9. The temperature-control system according to claim 8, characterized in that the channels (24) extend over the entire longitudinal extension of the sheet metal structure.

10. The temperature-control system according to claim 8, characterized in that the sheet metal structure is subdivided along the longitudinal extension into a plurality of strip-shapes portions (26) extending in a transverse direction, wherein the channels (24) of adjacent portions are offset in the transverse direction.

11. The temperature-control system according to claim 1, characterized by a media channel delimited by the intermediate space.

12. A motor vehicle with a temperature-control system according to claim 1.

13. The motor vehicle according to claim 12, characterized in that the refrigerator (12) comprises an air conditioning heat exchanger (16) provided for controlling the temperature of air (19) to be supplied to an interior space of the motor vehicle.

14. (canceled)

15. (canceled)

Description

[0026] The invention will be explained in more detail below on the basis of exemplary configurations illustrated in the drawings. In the drawings, shown are in a simplified representation respectively:

[0027] FIG. 1: a motor vehicle according to the invention;

[0028] FIG. 2a: a temperature-control system according to the invention in a first operative state;

[0029] FIG. 2b: the temperature-control system in a second and a third operative state;

[0030] FIG. 3: a cross-section through a temperature-control element according to the invention in accordance with a form of configuration;

[0031] FIG. 4: an alternative supporting structure for a temperature-control element according to FIG. 3 in a perspective representation;

[0032] FIG. 5: a cross-section through a portion of a temperature-control element according to the invention in accordance with a further form of configuration; and

[0033] FIG. 6 a top view of the temperature-control element according to FIG. 5.

[0034] FIG. 1 shows a motor vehicle according to the invention in a simplified representation. The motor vehicle is formed to be electrified and accordingly comprises at least one electrical traction motor 1, the driving power of which can be transferred to driven wheels 2 of the motor vehicle. The motor vehicle may in this case be formed as a battery-powered motor vehicle (BEV). For generating the travel driving power, it comprises in this case exclusively the one or more electrical traction motors 1 as well as a traction battery 3, which is inter alia provided for providing the electrical power required for driving the one or more traction motors 1. Alternatively, the motor vehicle may also be a hybrid vehicle. In this case, the motor vehicle moreover comprises an internal combustion engine (not shown), which is likewise provided to generate driving power at least temporarily, which will be transferred to the driven wheels of the motor vehicle. The hybrid vehicle may in this case be realized both in a configuration as a simple hybrid vehicle (HEV), in which the traction battery 3 which is usually dimensioned to be relatively small, is exclusively chargeable by generative utilization of the traction motor 1 or another generator, and also in a configuration as a so-called plug-in hybrid vehicle (PHEV), in which the traction battery 3 is also chargeable by connecting it to an external electrical energy source.

[0035] Both in charging the traction battery 3 and also when high electrical power is withdrawn from the traction battery 3, it can produce waste heat to a considerable extent, which needs to be dissipated in order to prevent the traction battery 3 from overheating. It should be ensured at the same time that the temperatures of the traction battery 3 will not fall below a defined lower threshold value, in order to avoid a reduction of the electrical storage capacity coming along with such relatively low temperatures. In order to achieve this, the traction battery 3 is integrated in a temperature-control system according to the invention. Such a temperature-control system is shown in FIG. 2 in a possible form of configuration.

[0036] The traction battery 3 formed as a battery cell unit according to the invention comprises in the temperature-control system according to FIG. 2 a plurality of battery cells 6, which are arranged electrically interconnected within a housing 4. A housing wall of this housing 4 has a temperature-control element according to the invention associated to it, wherein the temperature-control element 5 itself preferably forms this housing wall. If required, it may be provided for all of or at least a plurality of the housing walls of the battery cell unit 3 to be formed in the form of one or more temperature-control elements 4 according to the invention. Furthermore, one or more temperature-control elements 4 according to the invention may also be arranged between each of two battery cells 6 so as to realize a temperature-control of the battery cells 6 by means of the one or more temperature-control elements 5 which is as uniform as possible as a whole.

[0037] The temperature-control element 5 according to the invention comprises a housing within which a sorption material 7, for example zeolite or silica gel is arranged. The housing of the temperature-control element 5 is formed by two covering plates 8 (cf. FIGS. 3 and 5) as well as side walls (not shown). Via a connection line 9, the inner space of the housing accommodating the sorption material 7 is in fluid-conducting connection with a phase variator 10 formed as a heat exchanger. Into the connection line 9, a control valve 11 is integrated in this case, which is drivable by a control device (not shown). By means of the control valve 11, the fluid-conducting connection via the connection line 9 can be released or blocked. The temperature-control element 5 forms a sorption unit in conjunction with the phase variator 10 and the connection line 9 with the control valve 11 integrated therein, by means of which, in a principally controllable manner, thermal energy can be transferred between the sorption material 7 or the temperature-control element 5 (representing a sorption device of the sorption unit) and the phase variator 10 alternately in both directions. By means of the sorption unit, the temperature of the battery cells 6 of the battery cell unit 3 can accordingly be controlled and in this case be cooled or heated, if required.

[0038] For cooling the battery cells 6, the sorption unit is operated in a regeneration operation, for example, during a charging process for the traction battery 3 when the motor vehicle is not in operation, i.e. when the traction battery 3 is connected to an external electrical energy supply, wherein waste heat generated during charging of the battery cells, is utilized for the desorption of process medium (e.g. water) previously absorbed or adsorbed by the sorption material 7 of the one or more temperature-control element 5. For this purpose, a temperature control of the sorption material to a temperature of about 25 C. is already sufficient, for example. The battery cells 6 are cooled by this heat transfer to the sorption material 7 and the desorption of the process medium resulting therefrom. The water vapor released due to the desorption flows via the connection line 9 to the phase variator 10 when the control valve 11 is opened. In the phase variator 10, the water vapor condenses due to a cooling by a refrigerant of a refrigerator 12 of the temperature-control system, which likewise flows through the phase variator 10. When flowing through the phase variator 10, the refrigerant may have a temperature of 5 C., for example.

[0039] The refrigerator 12 comprises a refrigerant circuit 13, into which a condenser 14, a compressor 15, an evaporator 16 provided as an air conditioning heat exchanger of a motor vehicle according to the invention, as well as a plurality of control valves 11 are integrated. By means of the refrigerator 12, air 19 to be supplied for controlling the temperature of an interior (passenger) space of the motor vehicle can be cooled in case of demand in a known manner, to which purpose the refrigerant circulating within the refrigerant circuit 13 in a gaseous state is compressed by means of the compressor 15. The compressed, gaseous refrigerant subsequently condenses within the condenser 14, wherein the thermal energy released on this occasion is dissipated to ambient air 18. The refrigerant liquefied in this manner is then conveyed to the air conditioning heat exchanger 16, for example, by means of a pump not shown, in which heat exchanger it can relax, whereby the refrigerant is evaporated again, respectively transferred into the gaseous form. The refrigerant withdraws the thermal energy taken up during the evaporation from the air 19 likewise flowing through the air conditioning heat exchanger 16 and provided for air conditioning the interior space of the motor vehicle.

[0040] The phase variator 10 is connected to the refrigerant circuit 13 via separate connection lines 20 and three of the four control valves 17 in total. The thermal energy released within the phase variator 10 due to the condensation of the process medium during a regenerative operation of the sorption unit, is dissipated via the refrigerant. In this case, it may be provided for the refrigerant to be conveyed in a circuit by means of a pump 21 integrated into one of the connection lines 20 of the phase variator 20, which circuit otherwise comprises exclusively the phase variator 10 and the condenser 14 (cf. FIG. 2a), the condenser 14 serving in this case merely for re-cooling the refrigerant. A phase change of the refrigerant does not take place in this circuit. This refrigerant circuit correspondingly corresponds functionally to a cooling medium circuit.

[0041] Alternatively, the thermal energy released in the phase variator 10 during a regeneration operation of the sorption unit may also be dissipated via a refrigerant supplied within a circuit which additionally comprises a compressor 15. Thereby, the air conditioning heat exchanger 16 may be bypassed by means of a bypass 22 which can be released by means of the third control valve 17 of the refrigerator 12. In this case, the phase variator 10 of the sorption unit replaces the air conditioning heat exchanger 16 as an evaporator of the refrigerator 12. By means of the compressor 15, refrigerant in the gaseous state is then consequently compressed and supplied to the condenser 14, in which it condenses and is therewith liquefied. The liquid refrigerant is then supplied to the phase variator 10 by means of the pump 21, in which it evaporates. The thermal energy required for this evaporating of the refrigerant is thereby withdrawn from the process medium of the sorption unit, whereby it condenses. The corresponding circuit of the refrigerant is illustrated in FIG. 2b in an emphasized way (by arrows without filled-out surfaces).

[0042] During operation of the motor vehicle comprising the temperature-control system, it may be provided for the sorption unit to remain unutilized, for which purpose the control valve 11 of the sorption unit is then kept closed. This prevents the process medium from flowing over between the temperature-control element 5 and the phase variator 10. A possibly necessary cooling of the traction battery 3 can then preferably be realized by an additional cooling system of the motor vehicle (not shown), in which a cooling medium is conducted through cooling medium channels (not shown) integrated within the traction battery 3. Thermal energy which had thereby been transferred from the battery cells 6 to the cooling medium is subsequently transferred to ambient air in a cooling medium cooler of the cooling system. In this case, the coiling medium channels may also be integrated preferably into the one or more temperature-control elements 5 of the battery cell unit 3.

[0043] If the motor vehicle was not used for a longer period of time and, during this, was subjected to relatively cold ambient temperatures, the traction battery 3 will have a correspondingly low temperature when the motor vehicle is put into service (cold start) again, which results in a considerable restriction of the storage capacities of the battery cells 6. In order to bring the traction battery 3 after such a cold start of the motor vehicle as fast as possible to optimal temperatures with respect to the storage capacity, the sorption unit is then operated in a sorption operation, for which purpose the control valve 11 of the sorption unit is opened and moreover refrigerant is conveyed in a refrigerant circuit according, for example, to FIG. 2a or 2b (with the flow direction being reversed as compared to the regeneration operation (cf. arrows having a filled-out surface); in this case, the condenser 14 of the refrigerator 12 would be operated as an evaporator). Thereby, due to an appropriate configuration of the sorption unit (in particular also because the process medium is exclusively present within the sorption unit as a fluid, and the sorption unit moreover is operated at a negative pressure), the thermal energy which, when flowing through the phase variator 10, passes over from the refrigerant likewise having ambient temperature (for example, 0 C.) to the liquid process medium contained therein, is sufficient for evaporating this process medium, which then flows to the temperature-control element 5 via the connection line 9. The sorption material 7 contained within the temperature-control element 5 then absorbs or adsorbs the gaseous process medium while releasing heat. The thereby released thermal energy is in this case utilized for controlling the temperature of the battery cells 6 or heating the battery cells 6 of the battery cell unit/traction battery 3 to temperatures of about 25 C., for example.

[0044] In order to realize a transition of thermal energy as advantageous as possible between the battery cells 6 of the battery cell unit 3 and the sorption material of the one or more temperature-control elements 5, such a temperature-control element 5 comprises two covering plates 8 arranged at a distance from one another, which form an intermediate space within which a supporting structure 23 is arranged. Circumferentially, the intermediate space is enclosed by side walls (not shown). The side walls may in this case be parts of a separate frame, which is sealingly connected (for example, in a substance-fit manner, in particular soldered) to the covering plates 8. Alternatively, the side walls, however, may be formed by angled portions of one or two covering plates. Due to the supporting structure 23, the covering plates 8 are kept at a distance from one another. In the intermediate space between the covering plates 8, the sorption material 7 is moreover accommodated which contacts both the covering plates 8 and the supporting structure 23. The supporting structure 23, on the one hand, serves for the structural strength of the temperature-control element 5, and, on the other, for connecting the partial amounts of the sorption material 7 only contacting the supporting structure 23, to the covering plates 8 in a heat-conducting manner. In order to guarantee a heat conduction which is as good as possible, both the covering plates 8 and the supporting structure 23 are formed from materials of good heat-conductance, for example, aluminum.

[0045] The supporting structure 23 of the temperature-control element 5 represented in FIG. 3 is realized as a corrugated (i.e. meandering) sheet metal structure forming a plurality of channels 24 extending along a longitudinal extension (perpendicular to the drawing plane) of the sheet metal structure and running in parallel to one another, wherein the channels 24 extend uninterruptedly over the entire longitudinal extension of the sheet metal structure. The channels correspondingly represent free spaces within the intermediate space wherein the sorption material 7 is accommodated, which are separated from one another.

[0046] In the exemplary configuration according to FIG. 3, the sorption material 7 is provided in the form of coatings applied to the wall surfaces of the covering plates 8 and the supporting structure each delimiting the intermediate space. In this case, the layer thicknesses of the coatings of the sorption material are selected such that flow channels 25 are kept free. Due to these flow channels 25, the gaseous process medium of the sorption unit can get into contact with the sorption material 7 over a surface as large as possible.

[0047] In order to realize a distribution of the process medium to the individual flow channels 25, a distribution space (not shown) may be provided within the intermediate space delimited by the covering plates 8, into which all of the flow channels 25 open and which is moreover connected to the connection line 9 of the sorption unit.

[0048] The supporting structure 23 of a temperature-control element 5 according to FIG. 3 may also be configured in the form of a turbulence plate as illustrated in FIG. 4. Such a turbulence plate as well is a corrugated sheet metal structure forming a plurality of channels 24 extending along a longitudinal extension of the sheet metal structure and running in parallel to one another. In this case, the sheet metal structure is additionally subdivided along the longitudinal extension into a plurality of strip-shaped portions 26 extending in a transverse direction, wherein the channels 24 of adjacent portions 26 are offset from one another in the transverse direction.

[0049] FIGS. 5 and 6 show an alternative form of configuration for a temperature-control element 5 according to the invention, in which the supporting structure 23 is formed by the two covering plates 8 themselves, in that these respectively form a plurality of projections 27, wherein the projections 27 of the two covering plates 8 are opposite and contact one another. In this case, the covering plates 8 preferably are fixedly interconnected at these contact points, for example, by corresponding soldering points. Within the intermediate space delimited by the covering plates 8, sorption material 7 in turn is accommodated. This is represented in FIG. 5 by way of example as a bulk. Alternatively, however, a coating of the wall surfaces of the covering plates 8 delimiting the intermediate space (including the projections) with the sorption material 7 may also be provided in the temperature-control element 5 according to FIGS. 5 and 6.

LIST OF REFERENCE NUMERALS

[0050] 1 traction motor [0051] 2 wheel [0052] 3 traction battery/battery cell unit [0053] 4 housing of the battery cell unit [0054] 5 temperature-control element [0055] 6 battery cell [0056] 7 sorption material [0057] 8 covering plate of the temperature-control element [0058] 9 connection line [0059] 10 phase variator [0060] 11 control valve of the sorption unit [0061] 12 refrigerator [0062] 13 refrigerant circuit [0063] 14 condenser of the refrigerator [0064] 15 compressor of the refrigerator [0065] 16 air conditioning heat exchanger/evaporator of the refrigerator [0066] 17 control valve of the refrigerator [0067] 18 ambient air [0068] 19 air [0069] 20 connection line [0070] 21 pump [0071] 22 bypass of the refrigerant circuit [0072] 23 supporting structure of the temperature-control element [0073] 24 channel of the supporting structure [0074] 25 flow channel [0075] 26 portion of the corrugated sheet metal structure of the supporting structure [0076] 27 projection of a covering plate