COOLING SYSTEM

Abstract

A cooling system for a vehicle is disclosed. The cooling system includes a cooling circuit that is flowed through by a coolant. The cooling circuit includes a first heat source, a first radiator, a second heat source, and a second radiator. A first partial circuit is provided with the first heat source and the first radiator fluidically connected to one another. A second partial circuit is provided with the second heat source and the second radiator fluidically connected to one another. The first partial circuit and the second partial circuit can be hydraulically separated from one another at times such that the two partial circuits are flowed through by a part of the coolant, and hydraulically connected to one another at times such that the two partial circuits can be jointly flowed through by a common part of the coolant.

Claims

1. A cooling system for a vehicle , comprising: a cooling circuitthat can be flowed through by a coolant, the cooling circuitcomprises a first heat source coolable at a lower temperature level, a first radiator, a second heat source coolable at a higher temperature level and a second radiator, a first partial circuitof the cooling circuitis provided with the first heat sourceand the first radiatorfluidically connected to one another and a second partial circuitof the cooling circuitis provided with the second heat sourceand the second radiator fluidically connected to one another, wherein the first partial circuitand the second partial circuitcan be completely or almost completely hydraulically separated from one another at times such that the first partial circuits and the second partial circuit are flowable through by a part of the coolant, and wherein the first partial circuitand the second partial circuitcan be completely or almost completely hydraulically connected to one another at times such that the first partial circuits and the second partial circuit are jointly flowable through by a common part of the coolant.

2. The cooling system according to claim 1, wherein: the cooling circuitcomprises a first pumpand a second pump , the first pumpin the first partial circuitand the second pump in the second partial circuitare directly connected downstream or upstream of the first heat sourceand the second heat sourcerespectively, and the first pumps and the second pump can be regulated such a that the first partial circuits and the second partial circuit can be hydraulically separated from one another completely or almost completely and can be hydraulically connected to one another completely or almost completely.

3. The cooling system according to claim 1, wherein: the cooling circuit comprises an advance shut-off valveand a return shut-off valve, the advance shut-off valve and the return shut-off valveare connected between the first partial circuits and the second partial circuit, and the first partial circuits and the second partial circuit can be hydraulically separated from one another by the advance shut-off valveand the return shut-off valve.

4. The cooling system according to claim 1, wherein at least one of: the first partial circuitcomprises a warming-up bypass line connected in parallel with the first radiatorfor bypassing the first radiatorand a warming-up bypass valve , wherein the warming-up bypass line is closed and opened via the warming-up bypass valve, and the second partial circuit comprises a radiator bypass line connected in parallel with the second radiator for bypassing the second radiator and a radiator bypass valve, wherein the radiator bypass line is closed and opened via the radiator bypass valve.

5. The cooling system according to claim 1, further comprising a non-return valve directly connected downstream or upstream of the second heat sourceor of a pumpthat is directly connected downstream or upstream of the second heat source.

6. The cooling system according to claim 1, wherein at least one of: the first radiator with respect to an airflow direction is connected upstream of the second radiator, and the first radiator and the second radiator partially or completely overlap one another with respect to an airflow direction.

7. A method for operating a cooling system , comprising: providing a cooling circuit that is flowed through by a coolant, the cooling circuit including a first heat source coolable at a lower temperature level, a first radiator, a second heat source coolable at a higher temperature level, and a second radiator; the first heat source and the first radiator being fluidically connected to one another in a first partial circuit of the cooling circuit; the second heat source and the second radiator being fluidically connected to one another in a second partial circuit of the cooling circuit; hydraulically separating the first partial circuit and the second partial circuit completely or almost completely from one another at times; the cooling circuit further including a first pump directly connected upstream or downstream of the first heat source and a second pump directly connected upstream or downstream of the second heat source; and operating the cooling system in a braking mode, in a normal operating mode and in a warming-up mode.

8. The method according to claim 7, wherein the cooling systemis operated in the braking mode, wherein in the braking mode: the first pumpand the second pump are switched on; the first partial circuitand the second partial circuit are hydraulically separated from one another at times completely or almost completely; the first partial circuit is flowed through by a first part of the coolant and the second partial circuit by a second part of the coolant; and a temperature of the first part of the coolant in the first partial circuit is lower than a temperature of the second part of the coolant in the second partial circuit.

9. The method according to claim 7, wherein the cooling system is operated in the normal operating mode, wherein in the normal operating mode: the first pump is switched on and the second pump is switched off; the first partial circuit and the second partial circuit are hydraulically connected to one another at times completely or almost completely; and the first partial circuit and at least in regions the second partial circuit are flowed through by a common part of the coolant.

10. The method according to claim 9, wherein in the normal operating mode or in the braking mode the second radiator is flowed through or bypassed via a radiator bypass line.

11. The method according to claim 7, wherein the cooling system is operated in the warming-up mode, wherein in the warming-up mode: the second pump is switched off; the second partial circuit and the first radiator are separated from the first heat source via a warming-up bypass valveand are not flowed through; the first pump is switched on; and the first heat source and a warming-up bypass line connected in parallel with the first heat source are flowed through.

12. A vehicle, comprising: a cooling system, the cooling system including: a cooling circuit that is flowed through by a coolant; the cooling circuit including a first heat source coolable at a lower temperature level, a first radiator, a second heat source coolable at a higher temperature level, and a second radiator; the first heat source and the first radiator being fluidically connected to one another in a first partial circuit of the cooling circuit; the second heat source and the second radiator being fluidically connected to one another in a second partial circuit of the cooling circuit; wherein the first partial circuit and the second partial circuit are completely or almost completely hydraulically separated from one another in a braking mode such that the first partial circuit is flowed through by a first part of the coolant and the second partial circuit is flowered through by a second part of the coolant; and wherein the first partial circuit and the second partial circuit are completely or almost completely hydraulically connected to one another in a normal operating mode such that the first partial circuit and the second partial circuit are jointly flowed through by a common part of the coolant.

13. The vehicle according to claim 12, wherein the cooling circuit further includes a first pump and a second pump; the first pump being directly connected downstream or upstream of the first heat source in the first partial circuit, and the second pump being directly connected downstream or upstream of the second heat source in the second partial circuit.

14. The vehicle according to claim 13, wherein in the braking mode the first pump and the second pump are switched on.

15. The vehicle according to claim 13, wherein the normal operating mode the first pump is switched on and the second pump is switched off.

16. The vehicle according to claim 12, wherein the cooling circuit further comprises an advance shut-off valve and a return shut-off valve; the advance shut-off valve and the return shut-off valve being connected between the first partial circuit and the second partial circuit; and wherein the first partial circuit and the second partial circuit are hydraulically separated from one another by the advance shut-off valve and the return shut-off valve.

17. The vehicle according to claim 12, wherein the first partial circuit comprises a warming-up bypass line connected in parallel with the first radiator for bypassing the first radiator and a warming-up bypass valve, wherein the warming-up bypass line is closed and opened via the warming-up bypass valve.

18. The vehicle according to claim 12, wherein the second partial circuit comprises a radiator bypass line connected in parallel with the second radiator for bypassing the second radiator and a radiator bypass valve, wherein the radiator bypass line is closed and opened via the radiator bypass valve.

19. The vehicle according to claim 12, wherein the cooling circuit further comprises a non-return valve directly connected downstream or upstream of the second heat source.

20. The cooling system according to claim 4, wherein the warming-up bypass valve comprises a switching valve, a regulating valve, or a thermostat valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] It shows, in each case schematically

[0027] FIG. 1 a circuit diagram of a cooling system according to the invention in a first embodiment;

[0028] FIG. 2 a circuit diagram of the cooling system according to the invention in a second embodiment.

DETAILED DESCRIPTION

[0029] FIG. 1 shows a circuit diagram of a cooling system 1 according to the invention in a first embodiment. There, the cooling system 1 comprises a cooling circuit 2 with a first partial circuit 2a and with a second partial circuit 2b. In the first partial circuit 2a, a first heat source 3a and a first radiator 4a and in the second partial circuit 2b a second heat source 3b and a first radiator 4b are fluidically connected to one another. In addition, the first heat source 3a, the second heat source 3b, the first radiator 4a and the second radiator 4b are fluidically connected to one another in the cooling circuit 2. In other words, the two partial circuits 2a and 2b are fluidically connected to one another in the cooling circuit 2.

[0030] The cooling system 1 is provided for a vehicle, in particular for a utility vehicle. The first heat source 3a can be in particular a fuel cell and the second heat source 3b can be in particular a retarder or a brake resistor or another braking system. The first radiator 4a and the second radiator 4b are coolant-air radiators. The coolant is preferentially a liquid.

[0031] The cooling circuit 1 comprises a first pump 5a and a second pump 5b. The first pump 5a is directly connected in the first partial circuit 2a downstream of the first heat source 3a and the second pump 5b directly downstream of the second heat source 3b. However, it is also conceivable that the second pump 5b is directly connected upstream of the second heat source 3b. Further, a non-return valve 6 in the first partial circuit 2 is directly connected downstream of the first heat source 3a.

[0032] Further, the first partial circuit 2a comprises a warming-up bypass line 7 and a warming-up bypass valve 8. The warming-up bypass line 7 is connected opposite in parallel with the first heat source 3a and with the first radiator 4a and can be flowed through in a bypass mode. The warming-up bypass valve 8 can be switched in such a manner that the first radiator 4a can be bypassed via the warming-up bypass line 7. The second partial circuit 2b comprises a radiator bypass line 9 and a radiator bypass valve 10. Basically however the one radiator bypass line 9 can also be omitted. The radiator bypass line 9 is connected opposite in parallel with the second heat source and parallel with the second radiator 4b. Here, the radiator bypass valve 10 can be switched in such a manner that the second radiator 4b can be bypassed via the radiator bypass line 9. If a thermostatic regulation of the temperature of the coolant is not required in the second heat source 3b, the radiator bypass line 9 and the radiator bypass valve 10 can be omitted. By way of this, the cooling system 1 can be simplified.

[0033] The two radiators 4a and 4b can be flowed through by air in an airflow direction SR. Then, the first radiator 4a and the second radiator 4b can overlap one another in the airflow direction SR completely or in regions, wherein the first radiator 4a is connected upstream of the second radiator 4b with respect to the airflow direction SR. Behind the second radiator 4b, a blower 11 is additionally arranged, which can promote the flow of air through the second radiator 4b. It is also conceivable that a further blower – not shown here – is arranged behind the second radiator 4b. The two pumps 5a and 5b and the non-return valve 6 can be combined in a common module 14 – as indicated with interrupted lines. Because of this, cost advantages are created and the assembly of the cooling system 1 is simplified. In addition, the module 14 includes five liquid connections which lead to the first heat source 3a, to the second heat source 3b, to the warming-up bypass line 7, to the first radiator 4a and to the second radiator 4b.

[0034] FIG. 2 shows a circuit diagram of the cooling system 1 according to the invention in a second embodiment. In the second embodiment, the cooling circuit 2 comprises an advance shut-off valve 12 and a return shut-off valve 13. The advance shut-off valve 12 and the return shut-off valve 13 are connected between the two partial circuits 2a and 2b and can hydraulically separate the two partial circuits 2a and 2b from one another.

[0035] Regardless of the embodiment, the cooling system 1 can be operated by means of a method according to the invention in a braking mode, in a normal operating mode and in a warming-up mode.

[0036] In the braking mode, the first heat source 3a and the second heat source 3b are switched on and are cooled at the different temperature levels. The pumps 5a and 5b are switched on and the partial circuits 2a and 2b are hydraulically separated from one another. In the first embodiment of the cooling system 1, the pump pressure and the mass flow of the coolant in the two pumps 5a and 5b can be suitably adapted. In the second embodiment, the advance shut-off valve 12 and the return shut-off valve 13 can be closed. Because of this, the first partial circuit 2a is flowed through by a first part of the coolant and the second partial circuit 2b is flowed through by a second part of the coolant. The two parts of the coolant can have different temperatures and because of this, the heat source 3a can be cooled at a lower temperature level and the second heat source 3b at a higher temperature level. Because of this, an overheating of the first heat source 3a can be prevented and the cooling capacity in the second partial circuit 2b increased. The cooling capacity in the second partial circuit 2b can be adapted by means of the radiator bypass valve 10.

[0037] In the normal operating mode, the first heat source 3a is switched on and the second heat source 3b switched off. Accordingly, only the first heat source 3a has to be cooled in the normal operating mode. The first partial circuit 2a and the second partial circuit 2b are not hydraulically separated from one another here and are flowed through by a common part of the coolant. To this end, the second pump 5b is switched off in the first embodiment and the second pump 5b switched off in the second embodiment and the advance shut-off valve 2 and the return shut-off valve 13 are open. The first pump 5a by contrast is switched on. Accordingly, the coolant can flow through the first heat source 3a and the first radiator 4a in the normal operating mode. The second radiator 4b can be flowed through or bypassed via the radiator bypass line 9. Here, the flow through the second heat source 3b is prevented by the non-return valve 6 if applicable.

[0038] In the warming-up mode, the first heat source 3a is switched on and the second heat source 3b switched off. In the warming-up mode, the second pump 5b is switched off and the warming-up bypass valve 10 switched in such a manner that the second partial circuit 2b and the first radiator 4a are not flowed through. By contrast, the first pump 5a is switched on and delivers a reduced part of the coolant through the first heat source 3a and the warming-up bypass line 7.