METHOD FOR OPERATING A COOLING SYSTEM FOR A VEHICLE AND COOLING SYSTEM

Abstract

A method for operating a cooling system for a vehicle, for example a rail vehicle, may include circulating a coolant in a first cooling circuit and in a second cooling circuit. A first heat source to be cooled may be arranged in the first cooling circuit and a second heat source to be cooled may be arranged in the second cooling circuit. The coolant may be circulated by pumping the coolant in the first cooling circuit via a first pumping device, and pumping the coolant in the second coolant circuit via a second pumping device. The first pumping device and the second pumping device may each be operated in a normal mode. The method may further include cooling the coolant via at least one cooling element arranged in at least one of the first cooling circuit and the second cooling circuit.

Claims

1. A method for operating a cooling system for a vehicle, comprising: circulating a coolant in a first cooling circuit and in a second cooling circuit, wherein a first heat source to be cooled is arranged in the first cooling circuit and a second heat source to be cooled is arranged in the second cooling circuit; cooling the coolant via at least one cooling element arranged in at least one of the first cooling circuit and the second cooling circuit; wherein circulating the coolant includes pumping the coolant in the first cooling circuit via a first pumping device arranged in the first cooling circuit and pumping the coolant in the second coolant circuit via a second pumping device arranged in the second cooling circuit; wherein the first pumping devices and the second pumping device are each operated in a normal mode; and in response to a first emergency mode in which the second pumping device provides an at least reduced pumping capacity, branching off the coolant from the second cooling circuit downstream of the second heat source and pumping the coolant via the first pumping device and returning the coolant to the second cooling circuit upstream of the second heat source.

2. The method according to claim 1, further including, in response to a second emergency mode in which the first pumping device provides an at least reduced pumping capacity, branching off the coolant from the first cooling circuit downstream of the first heat source and pumping the coolant via the second pumping device and returning the coolant to the first cooling circuit upstream of the first heat source.

3. The method according to claim 1, that further including, in response to a support mode in which a temperature of the coolant in one of the first cooling circuits and the second cooling circuit upstream of the appurtenant one of the first heat source and the second heat source increases above a predefined value, pumping the coolant in the one of the first cooling circuit and the second cooling circuit with the temperature increase of the coolant via the appurtenant one of the first pumping device and the second pumping device arranged in the other one of the first cooling circuit and the second cooling circuit.

4. A cooling system for a vehicle, comprising: a first cooling circuit and a second cooling circuit, wherein a coolant circulates in the first cooling circuit and in the second cooling circuit; a first heat source to be cooled arranged in the first cooling circuit; a second heat source to be cooled arranged in the second cooling circuit; a first pumping device arranged in the first cooling circuit for pumping the coolant; a second pumping device arranged in the second cooling circuit for pumping the coolant; at least one cooling element arranged in at least one of the first cooling circuit and the second cooling circuit for cooling the coolant; a branch line providing a fluidic connection between the first cooling circuit and the second cooling circuit upstream of the first pumping device and upstream of the second pumping device and downstream of the second heat source; a first return line providing a fluidic connection between the first cooling circuit and the second cooling circuit, wherein the first return line branches off from the first cooling circuit downstream of the first pumping device and opens into the second cooling circuit upstream of the second heat sources; a valve for regulating a flow of coolant arranged in the first return line; and in response to a first emergency mode in which the second pumping device provides an at least reduced pumping capacity, the coolant is branched off from the second cooling circuit downstream of the second heat source and pumped via the first pumping device then returned to the second cooling circuit upstream of the second heat source.

5. The cooling system according to claim 4, further comprising a second return line providing a fluidic connection between the second cooling circuit and the first cooling circuit, wherein the second return line branches off from the second cooling circuit downstream of the second pumping device and opens into the first cooling circuit downstream of the first heat source, and wherein another valve for regulating a flow of the coolant is arranged in the second return line.

6. The cooling system according to claim 4, further comprising an other valve arranged in the second cooling circuit downstream of the second pumping device and upstream of the first return line, wherein the other valve is configured to prevent flow of the coolant from the first return line to the second pumping device.

7. The cooling system according to claim 4, further comprising another a valve for regulating the flow of the coolant arranged in the branch line.

8. The cooling system according to claim 4, the valve is configured as a non-return valve.

9. The cooling system according to claim 4, further comprising a control device configured communicate control commands.

10. The cooling system according to claim 4, further comprising at least one pressure-equalizing container for equalizing a pressure in the coolant.

11. The cooling system according to claim 10, wherein the at least one pressure-equalizing container includes a first pressure equalizing container and a second pressure equalizing container, wherein the first pressure equalizing container is for the first cooling circuit and the second pressure equalizing container is for the second cooling circuit.

12. The cooling system according to claim 4, wherein the branch line is located upstream of the at least one cooling element.

13. The cooling system according to claim 4, further comprising a throttle device for regulating a flow of the coolant arranged in at least one of the branch line and the first return lines.

14. The cooling system according to claim 4, wherein the at least one cooling for cooling the coolant is common to both of the first cooling circuit and the second cooling circuit.

15. The cooling system according to claim 4, wherein at least one of the first heat source and the second heat source is a component of a rail vehicle, and wherein the first emergency mode is when the second pumping device fails.

16. The cooling system according to claim 5, further comprising a throttle valve for regulating a flow of the coolant arranged in the second return line.

17. The method according to claim 1, wherein circulating the coolant includes cooling the first heat source and the second heat source, and wherein at least one of the first heat source and the second heat source is a component of a rail vehicle; and wherein the first emergency mode is when the second pumping device fails.

18. The method according to claim 1, further comprising regulating a flow of the coolant through the first cooling circuit via a valve.

19. The method according to claim 1, further comprising regulating a flow of the coolant through the second cooling circuit via a valve arranged in the second cooling circuit configured to prevent flow of the coolant from the first return line to the second pumping device.

20. The method according to claim 1, further comprising equalizing a pressure of the coolant via at least one pressure-equalizing container.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In the figures, in each case schematically and shown in a highly simplified and circuit-diagram-like manner,

[0034] FIG. 1 shows a cooling system in a first operating state,

[0035] FIG. 2 shows the cooling system in a second operating state,

[0036] FIG. 3 shows the cooling system in a further operating state,

[0037] FIG. 4 shows the cooling system in the second operating state in another exemplary embodiment of the cooling system,

[0038] FIG. 5 shows the cooling system in the first operating state in another exemplary embodiment of the cooling system,

[0039] FIG. 6 shows the cooling system from FIG. 5 in a third operating state,

[0040] FIG. 7 shows the cooling system from FIG. 5 in a third operating state.

DETAILED DESCRIPTION

[0041] FIG. 1 shows a cooling system 1 which is part of a vehicle 2, in particular a rail vehicle 2′, for example an electrically driven rail vehicle 2′. The cooling system 1 comprises a first cooling circuit 3 and a second cooling circuit 4 in which a coolant is circulating. With the aid of the coolant, a heat source 5, 6 is cooled in the respective cooling circuit 3, 4, the heat source being arranged in the appurtenant cooling circuit 3, 4 and having coolant flowing through it or around it. In this case, a first such heat source 5 is arranged in the first cooling circuit 3, which for example can be a drive component 7 of the vehicle 2. A second such heat source 6 is arranged in the second cooling circuit 4, which can also be a drive component 7 of the vehicle 2. The drive component 7 arranged in the second cooling circuit 4 is more critical with regard to cooling than the drive component 7 arranged in the first cooling circuit 3. That is, the drive component 7 arranged in the second cooling circuit 4 for driving the vehicle 2 requires a permanent cooling and/or is more important for driving the vehicle 2 than the drive component 7 arranged in the first cooling circuit 3.

[0042] A first pumping device 8, for example, a pump 9, in particular a circulating pump 9′ is arranged in the first cooling circuit 3 for pumping the coolant. In addition, a second pumping device 10, which for example is configured as a pump 9, in particular as circulating pump 9′ is arranged in the second cooling circuit 4 for pumping the coolant. The cooling circuits 3, 4 have a common cooling means 11 for cooling the coolant which is arranged in the respective cooling circuit 3, 4 downstream of the pumping device 8, 10 and upstream of the heat source 5, 6. The cooling means 11 has a cooling fluid flowing through it for cooling the coolant, which flows through the cooling means 11 in a cooling fluid flow direction 13. In this case, the first cooling circuit 3 and the second cooling circuit 4 are guided separately through the cooling means 11, wherein the first cooling circuit 3 is guided in relation to the cooling fluid flow direction 13 upstream of the second cooling circuit 4 through the cooling means 11. FIG. 1 shows a normal mode 12 of the cooling system 1 in which the first cooling circuit 3 and the second cooling circuit 4 are separated fluidically and the first pumping device 8 pumps the coolant in the first cooling circuit 3 whilst the second cooling device 10 pumps the coolant in the second cooling circuit 4. As a result, a flow of the coolant is obtained in the respective cooling circuit 3, 4 wherein the following references refer to the cooling circuits 3, 4 in the sense of upstream and downstream of the flow in the respective cooling circuits 3, 4 in the normal mode 12.

[0043] The cooling system 1 has a branch line 14 which fluidically interconnects the first cooling circuit 3 and the second cooling circuit 4. Here the branch line 14 runs from a first branch point 15 downstream of the first heat source 5 and upstream of the first pumping device 8 in the first cooling circuit 3 as far as a second branch point 16 arranged downstream of the second heat source 6 and upstream of the second pumping device 10 in the second cooling circuit 4. A valve 17 is arranged in the branch line 14 which in the example shown is configured as a non-return valve 18. The non-return valve 18 here only allows a flow of coolants from the second cooling circuit 4 to the first cooling circuit 3. The non-return valve 18 is loaded with a counter-pressure which is symbolized by a spring 19. That is, the counter-pressure must be overcome to open the valve 17 for the purpose of flow of the coolant from the second cooling circuit 4 to the first cooling circuit 3. A first return line 20 connects the first cooling circuit 3 fluidically to the second cooling circuit 4 and runs from the first return point 21 of the first return line 20 in the first cooling circuit 3 as far as a second return point 22 of the first return line 20 in the second cooling circuit 4. Here the first return point 21 of the first return line 20 is arranged downstream of the first pumping device 8 and upstream of the first heat source 5 and downstream of the cooling means 11. The second return point 22 of the first return line 20 is arranged upstream of the second heat source 6 and downstream of the second pumping device 10 as well as downstream of the cooling means 11. A valve 17 is arranged in the first return line 20 which like the valve 17 arranged in the branch line 14 is configured as a non-return valve 18 and is exposed to a counter-pressure and merely allows a flow of coolant from the first cooling circuit 3 to the second cooling circuit 4. A valve 17 is arranged in the second cooling circuit 4 upstream of the second return point 22 of the first return line 20 and downstream of the second pumping device 10 as well as downstream of the cooling means 11, which valve is also configured as a non-return valve 18, is exposed to a counter-pressure and merely allows a flow of coolant from the pumping device 10 to the second heat source 6.

[0044] In the normal mode 12 shown in FIG. 1, as mentioned previously, the cooling circuits 3 and 4 are separate from one another. Accordingly no coolant flows through the branch line 14 or through the first return line 20. In the diagram sections through which coolant does not flow are shown by dashed lines. That is, in the normal mode 12 shown in FIG. 1, the branch line 14 and the first return line 20 are shown by dashed lines.

[0045] In the example shown the respective cooling circuit 3, 4 is further assigned a pressure-equalizing container 23. That is, that the first cooling circuit 3 is assigned a first such pressure-equalizing container 23′ whilst the second cooling circuit 4 is assigned a second such pressure-equalizing container 23″ wherein the respective pressure-equalizing container 23 serves to equalize the pressure of the coolant in the appurtenant cooling circuit 3, 4.

[0046] FIG. 2 shows an emergency mode 24 of the cooling system 1. In the emergency mode 24 the second pumping device 10 of the second cooling circuit 4 delivers a reduced capacity or fails, wherein FIG. 2 shows a state in which the second pumping device 10 has failed. In the emergency mode 24 coolant has branched off downstream of the second heat source 6 from the second cooling circuit 4, is supplied to the first cooling circuit 24 upstream of the pumping device 8, pumped by means of the first pumping device 8 and supplied to the second cooling circuit 4 again upstream of the second heat source 6. That is that in the event of failure of the second pumping device 10 or in the case of a reduced capacity of the second pumping device 10, the first pumping device 8 is used as emergency pumping device of the second cooling circuit 4. As a result, the second heat source 6 arranged in the second cooling circuit 4 is also cooled when the second pumping device 10 fails or delivers a reduced capacity. In this case, the coolant is supplied from the second cooling circuit 4 via the branch line 14 to the first cooling circuit 3 and returned via the first return line to the second cooling circuit 4. In the emergency mode 24 in the example shown the cooling of the coolant via the cooling means 11 is therefore accomplished exclusively in the first cooling circuit 3. The non-return valve 18 in the branch line 14 ensures that the coolant in the branch line 14 flows from the second cooling circuit 4 to the first cooling circuit 3 whilst the non-return valve 18 in the first return line 20 ensures that the coolant flows via the first return line 20 from the first cooling circuit 3 to the second cooling circuit 4. The non-return valve 18 arranged in the second cooling circuit 4 further ensures that the coolant flowing via the first return line 20 to the second cooling circuit 4 does not pass via the first pumping device 10 to the branch line 14 but exclusively via the second heat source 6 to the branch line 14. This non-return valve 18 therefore ensures that the coolant in the emergency mode 24 flows in the correct direction or not in the “wrong” direction.

[0047] The non-return valves 18 exposed to counter-pressure in the branch line 14 and in the first return line 20 ensure that the valves open in a self-regulating manner when the pressure relationships between the first cooling circuit 3 and the second cooling circuit 4 changes as a result of the falling pressure in the second cooling circuit 4 due to the at least reduced capacity of the second pumping device 10 in the second cooling circuit 4. That is in particular that the emergency mode 24 can be adjusted in a self-regulating manner. Alternatively or additionally, it is conceivable to provide the cooling system 1 or the vehicle 2 with a control device 25 which is connected to the corresponding valves 17 in a communicating manner in order to actuate these. The control device 25 is additionally connected in a communicating manner to at least the second pumping device 10, preferably to both pumping devices 8, 10 in order in particular to actuate the respective pumping device 8, 10 and/or interrogate the pumping capacity of the respective pumping device 8, 10. In addition, a temperature sensor 30 for determining the temperature of the coolant upstream or downstream of the appurtenant heat source 5, 6, which is also connected to the control device 25 in a communicating manner, can be provided upstream and/or downstream of the respective heat source 5, 6.

[0048] In the cooling system 1 shown in FIGS. 1 and 2, the second cooling circuit 4 or the second heat source 6 is prioritized. That is that the emergency mode 24 can only be operated in favour of the second heat source 6 or the second cooling circuit 7. If therefore according to FIG. 3 the first pumping device 8 fails or it delivers a reduced capacity, wherein FIG. 3 shows a state in which the first pumping device 8 has failed, no pumping of the coolant in the first cooling circuit 3 takes place, accordingly the first cooling circuit 3 is shown by a dashed line. The same applies to the branch line 14 and the first return line 20.

[0049] FIG. 4 shows a further exemplary embodiment of the cooling system 1 in simplified manner, where the emergency mode 24 is shown in FIG. 4. This exemplary embodiment differs from the exemplary embodiments shown in FIGS. 1 to 3 in particular in that only a single such pressure-equalizing container 23 is provided which is fluidically connected to the branch line 14. This results in a reduced installation space requirement and a reduced number of components of the cooling system 1. In addition, no such valve 17 is provided in the branch line 14. The fluidic connection between the first cooling circuit 3 and the second cooling circuit 4 via the branch line 14 can here in particular be accomplished with the aid of the pressure-equalizing container 23 which can be connected to the control device 25 in a communicating manner. This has the result that both cooling circuits 3, 4 are at the same pressure level on the suction side, that is upstream of the pumping devices 8, 10. If a prioritization of the second cooling circuit 4 is required, a valve 17 can be provided (not shown) between the pressure-equalizing container 23 and the first branch point 15 in order, in the event of a failure of the first pumping device 8 and/or in the case of a leak in the first cooling circuit 3, to separate the second cooling circuit 4 and the pressure-equalizing container 23 from the first cooling circuit 3 so that in such cases a regulated operation of the second cooling circuit 4 is further possible.

[0050] FIG. 5 shows a further exemplary embodiment of the cooling system 1 wherein the normal mode of the cooling system 1 is accomplished in FIG. 5. This exemplary embodiment differs from the exemplary embodiment shown in FIG. 4 in particular in that the first return line 20 is arranged upstream of the cooling means 11. In this case, the first return point 21 of the first return line 20 is arranged downstream of the first pumping device 8 and upstream of the cooling means 11 whereas the second return point 22 of the first return line 20 is arranged downstream of the second pumping device 10 and upstream of the cooling means 11. In this exemplary embodiment, a second return line 26 is additionally provided which runs from the first return point 27 of the second return line 26 in the first cooling circuit 3 as far as a second return point 28 of the second return line 26 in the second cooling circuit 4. The first return point 27 of the second return line 26 is arranged upstream of the first heat source 5 whilst the second return point 28 of the second return line 26 is arranged downstream of the second pumping device 10. In the example shown, the first return point 27 of the second return line 26 is arranged upstream of the first return point 21 of the first return line 20 whilst the second return point 28 of the second return line 26 is arranged upstream of the second return point 22 of the first return line 20, wherein a reversed sequence is also conceivable. A valve 17 configured as a non-return valve 18 is arranged in the second return line 26, which valve is exposed to a counter-pressure and only allows a flow of coolant from the second cooling circuit 4 to the first cooling circuit 3. In the example shown a throttle device 29 is additionally arranged in the respective return line 20, 26 which regulates the flow of coolant through the appurtenant line 20, 26. This regulation by means of the throttle device 29 can be accomplished additionally or alternatively to the valve 17, in particular to the non-return valve 18.

[0051] In the normal mode 12 shown in FIG. 5, the first cooling circuit 3 and the second cooling circuit 4 are fluidically separated. That is, that the fluidic connection between the cooling circuits 3 and 4 is interrupted via the lines 14, 20, 26.

[0052] FIG. 6 shows the cooling system 1 in the emergency mode 24 in which the second pumping device 10 delivers a reduced capacity or fails, wherein FIG. 6 shows a state in which the second pumping device 10 has failed. In this case, similarly to the variants shown in FIGS. 2 and 4, the coolant is branched off from the second cooling circuit 4 downstream of the second heat source 6 to the first cooling circuit 3, the coolant is pumped through the first pumping device 8 and the coolant is returned to the second cooling circuit 4 upstream of the second heat source 6. The coolant is branched off via the branch line 14 whilst the coolant is returned via the first return line 20. For the sake of better clarity, the throttle devices 29 are not shown in FIG. 6 although these can be present instead of the valves 17 show or alternatively to these. Since the first return line 20 opens at the second return point 22 into the second cooling circuit 4, which is located upstream of the cooling means 11, after return to the second cooling circuit 4 the coolant is guided through the cooling means 11 before it is supplied to the second heat source 6. In the emergency mode 24 shown in FIG. 6, the second return line 26 is blocked in such a manner that coolant cannot flow between the first cooling circuit 3 and the second cooling circuit 4.

[0053] By means of the second return line 26 however, in a further emergency mode 31 which is hereinafter designated as second emergency mode 31, whilst the previously explained emergency modes 24 are designated as first emergency mode 24, it is possible to use the second pumping device 10 for pumping the coolant in the first cooling circuit 3 when the first pumping device 8 delivers a reduced pumping capacity or fails.

[0054] Such a second emergency mode 31 is shown in FIG. 7, wherein FIG. 7 shows a state in which the first pumping device 8 has failed. In the second emergency mode 31 coolant is branched off from the first cooling circuit 3 downstream of the first heat source 5, supplied to the second cooling circuit 4 upstream of the second pumping device 10 and returned to the first cooling circuit 3 upstream of the first heat source 5. In the example shown, the coolant is branched off via the branch line 14 whilst the coolant is returned via the second return line 26. In this case, the coolant flows in the second cooling circuit 3 as a result of the arrangement of the first return point 27 of the second return line 26 in the first cooling circuit 3 upstream of the cooling means 11 through the cooling means 11 before it is supplied to the first heat source 5.

[0055] In the cooling system shown in FIGS. 5 to 7, there is therefore no prioritization of one of the cooling circuits 3, 4 or the appurtenant heat source 5, 6. Naturally however it is possible to make such a prioritization by means of corresponding control of the valves 17 and/or the throttle devices 29.

[0056] In all the examples shown it is further possible in a support mode to use the pumping device 8, 10 of the other cooling circuit 3, 4 for pumping the coolant in one cooling circuit 3, 4 when a temperature which lies above a predefined value is determined in this cooling circuit upstream of the appurtenant heat source 5, 7. It is for example possible to use the first pumping device 8 in addition to the second pumping device 10 for pumping the coolant in the second cooling circuit 4 when the coolant upstream of the second heat source 6 has a temperature which lies above the predefined value. The temperature is determined in this case by means of the temperature sensor 30 arranged upstream or downstream of the second heat source 6.

[0057] Similarly to this, in a second support mode the second support mode the second pumping device 10 can be used in addition to the first pumping device 8 for pumping the coolant in the first cooling circuit 3 when a temperature is determined upstream of the first heat source 5, in particular by means of the corresponding temperature sensor 30, which lies above a value which can differ from the value in the first support mode. In the support mode therefore, compared to the emergency mode there is no reduction in the capacity of the appurtenant pumping device 8, 10 or no failure of the appurtenant pumping device 8, 10.

[0058] In all the exemplary embodiments, the corresponding valves 17 or throttle devices 29 allow a corresponding regulation of the volume flow or the amount of branched-off and returned coolant.