FUEL CELL SYSTEM ASSEMBLY

Abstract

The invention relates to a fuel cell system assembly comprising at least two coupled fuel cell systems (A, B) that can be operated at different load points, each fuel cell system (A, B) being connected to a respective cooling circuit (3A, 3B) comprising a circulating coolant, via a coolant supply line (1A, 1B) and a coolant drain line (2A, 2B). According to the invention, the cooling circuits (3A, 3B) are coupled via a common return line (4), via which the coolant supply lines (1A, 1B) can be supplied with coolant, and a return conduit of at least one ancillary unit (5, 6), for example an electric heating device (5) and/or a heater core (6), is connected to the common return line (4).

Claims

1. A fuel-cell-system combination comprising at least two coupled fuel-cell systems (A, B) which are configured to be operated at different load points, wherein each fuel-cell system (A, B) is connected to in each case one cooling circuit (3A, 3B), with a circulating coolant, via a coolant feed line (1A, 1B) and a coolant discharge line (2A, 2B), wherein the cooling circuits (3A, 3B) are coupled via a common recirculation line (4), via which the coolant feed lines (1A, 1B) are supplied with coolant, wherein a return (5) with at least one auxiliary unit (6) is connected to the common return line (4).

2. The fuel-cell-system combination as claimed in claim 1, wherein at least two auxiliary units (6.1, 6.2), which are connected in parallel or in series, are connected to the common recirculation line (4) via the return (5).

3. The fuel-cell-system combination as claimed in claim 1, wherein the coolant discharge lines (2A, 2B) of the fuel-cell systems (A, B) are each configured to be connected to the corresponding coolant feed line (1A, 1B) of the respective fuel-cell system (A, B) via a branch valve (7A, 7B) and a branch line (8A, 8B).

4. The fuel-cell-system combination as claimed in claim 3, wherein an inlet (9) of the at least one auxiliary unit (6) is connected to at least one branch line (8A, 8B), wherein a pump (10) is arranged in the inlet (9).

5. The fuel-cell-system combination as claimed in claim 1, wherein in each case one pump (11A, 11B) is arranged in the coolant feed lines (1A, 1B) of the fuel-cell systems (A, B).

6. The fuel-cell-system combination as claimed in claim 5, wherein the branch lines (8A, 8B) of the fuel-cell systems (A, B) each open out into the respective coolant feed line (1A, 1B) upstream of the pump (11A, 11B).

7. The fuel-cell-system combination as claimed in claim 1, wherein at least one heat exchanger (12A, 12B) is arranged in the cooling circuits (3A, 3B) or in the common recirculation line (4).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention will be discussed in more detail below on the basis of the appended drawings, in which:

[0018] FIG. 1 shows a schematic illustration of a fuel-cell-system combination according to the invention,

[0019] FIG. 2 shows an enlarged detail of FIG. 1 in the region of the connected auxiliary units, and

[0020] FIG. 3 shows a modification of the embodiment illustrated in FIG. 2.

DETAILED DESCRIPTION

[0021] A fuel-cell-system combination comprising two fuel-cell systems A and B can be seen by way of example in FIG. 1. Each fuel-cell system A, B can be operated at a different load point. Consequently, the cooling requirement of the fuel-cell systems A, B can vary. Each fuel-cell system A, B is therefore assigned a cooling circuit 3A, 3B, wherein, in the present case, the cooling circuits 3A, 3B are coupled via a common recirculation line 4. Accordingly, the same coolant circulates in the two cooling circuits 3A, 3B.

[0022] The first fuel-cell system A is connected to the cooling circuit 3A via a first coolant feed line 1A and a first coolant discharge line 2A. The second fuel-cell system B is connected to the cooling circuit 3B via a second coolant feed line 1B and a second coolant discharge line 2B. A heat exchanger 12A, 12B is arranged in each cooling circuit 3A, 3B in order to extract heat from heated coolant which is introduced from a fuel-cell system A, B into the respective cooling circuit 3A, 3B via the respective coolant discharge line 2A, 2B. The heat exchangers 12A, 12B are in each case incorporated in the respective cooling circuit 3A, 3B upstream of the common recirculation line 4. Alternatively, a heat exchanger 12 may be arranged in the common recirculation line 4.

[0023] In order to individually set the temperature of the coolant in the respective coolant feed lines 1A, 1B of the fuel-cell systems A, B, heated coolant can be introduced from the coolant discharge lines 2A, 2B into the coolant feed lines 1A, 1B. For this purpose, the coolant discharge lines 2A, 2B are each connected to the corresponding coolant feed line 1A, 1B via a branch valve 7A, 7B and a branch line 8A, 8B. The branch lines 8A, 8B each open out into the respective coolant feed line 1A, 1B upstream of a pump 11A, 11B. With the aid of pumps 11A, 11B, each fuel-cell system A, B can be fed the presently required quantity of coolant.

[0024] The fuel-cell-system combination illustrated in FIG. 1 furthermore has two auxiliary units 6 which are integrated in an auxiliary circuit, which comprises an inlet 9 and a return 5. The auxiliary circuit is illustrated greatly enlarged in FIG. 2. Via the inlet 9, which has multiple branches, the auxiliary units 6 are connected to the branch lines 8A, 8B. Via a pump 10 arranged in the inlet 9, the auxiliary units 6 are fed coolant from the branch lines 8A, 8B. The auxiliary units 6 are connected in parallel in the present case, but may also be connected in series, as illustrated by way of example in FIG. 3. Via the return 5 of the auxiliary circuit, the auxiliary units 6 are connected to the common recirculation line 4.

[0025] The auxiliary units 6 involve in the present case an electrical heating device 6.1 by means of which the fuel-cell systems A, B can be fed heated coolant during a cold start. The electrical heating device 6.1 may thus be used as an independent heater for all the fuel-cell systems A, B. The quantity of coolant heated by means of the electrical heating device 6.1 moreover has to cover only a short coolant distance to the fuel-cell systems A, B. Furthermore, only a comparatively small quantity of coolant has to heated, and so the efficiency of the independent heater is increased.

[0026] The second auxiliary unit 6 is in the present case a heating heat exchanger 6.2 which uses the waste heat of the fuel-cell systems A, B for heating a passenger compartment. For this purpose, the heating heat exchanger 6.2 is fed heated coolant from the fuel-cell systems A, B via the branch lines 8A, 8B and the inlet 9. In this way, the waste heat of the fuel-cell systems A, B can be used for increasing the efficiency of the heating heat exchanger 6.2.