SUBMERSIBLE WITH COMMON REDUNDANT COOLING CIRCUITS, FOR EXAMPLE, A FUEL CELL AND A BATTERY

Description

[0001] The invention relates to a submarine with a fuel cell and a battery, each having its own cooling circuit.

[0002] Until now, submarines have almost exclusively used lead-acid battery systems. These are tried and tested and therefore enjoy widespread market acceptance. Furthermore, the technology is relatively robust.

[0003] Lead-acid batteries are relatively unproblematic in terms of cooling. Cooling is only necessary at very high power outputs. Therefore, if the cooling system fails, simply reducing the maximum power output will ensure continued safe operation. A redundant cooling system is thus unnecessary.

[0004] Due to their better power-to-weight ratio, there is currently a growing desire to use lithium-based batteries. This is happening both in new boat construction and in replacing existing lead-acid batteries with new systems to increase capacity and thus range.

[0005] However, temperature is a significantly more critical factor for lithium-based batteries, particularly due to the temperature sensitivity of the control electronics required for operation. Therefore, the cooling system becomes considerably more important.

[0006] A storage unit for a propulsion system in a vehicle is known from US patent 2014 / 0150485A1. A cooling circuit for a fuel cell in a submarine, where the submarine also contains accumulators, is known from WO 2004 / 030182A1.

[0007] The object of the invention is to provide a safe submarine while keeping the weight and volume of the equipment as low as possible.

[0008] This problem is solved by the submarine with the features specified in claim 1. Advantageous further developments are described in the dependent claims, the following description, and the drawing.

[0009] The submarine according to the invention comprises a first heat-generating device, for example an energy storage device, and a second heat-generating device, for example a fuel cell device. The first heat-generating device, for example an energy storage device, is cooled via a second cooling circuit, for example an energy storage cooling circuit, and the second heat-generating device, for example the fuel cell device, is cooled via a first cooling circuit, for example a fuel cell cooling circuit. The second cooling circuit comprises a first circulation pump, and the second cooling circuit comprises a second circulation pump.

[0010] According to the invention, the second cooling circuit includes a third circulation pump, which is arranged in parallel to the second circulation pump. This provides redundancy for the second cooling circuit. If the second circulation pump fails, the third circulation pump can simply be activated and take over. The third circulation pump does not need to have the full capacity of the second circulation pump. If the capacity of the third circulation pump is lower than that of the second circulation pump, in the sense that it has or generates a lower flow rate per unit of time, the power of the heat-generating process can be throttled accordingly via the control of the first waste heat-generating device, for example, an energy storage device, thus limiting, for example, the power output of the energy storage device.

[0011] Furthermore, the submarine has a first cooling circuit connection. This connection links the first cooling circuit, located before the first circulation pump, to the second cooling circuit, located before the second circulation pump and after the branch to the third circulation pump. The submarine also has a second cooling circuit connection. This connection links the first cooling circuit, for example, the fuel cell cooling circuit, located after the first circulation pump, to the second cooling circuit, for example, the energy storage cooling circuit, located after the second circulation pump and before the merge point at the third circulation pump. This allows the coolant from the first cooling circuit to be routed through either the first or the second circulation pump.In order to control this in a targeted manner, a first switching valve is arranged in the first cooling circuit connection, a second switching valve is arranged in the second cooling circuit connection, a third switching valve is arranged in the second cooling circuit before the connection with the first cooling circuit connection and after the branch to the third circulation pump, and a fourth switching valve is arranged in the second cooling circuit after the connection with the second cooling circuit connection and before the merging with the third circulation pump.

[0012] Normally, the first and second switching valves are closed, and the coolant from the first cooling circuit is circulated by the first circulation pump. The third and fourth switching valves are open, so the coolant from the second cooling circuit is circulated by the second circulation pump.

[0013] If the first circulation pump fails, the third and fourth diverter valves close, and the first and second diverter valves open. This allows the coolant from the first cooling circuit to be circulated by the second circulation pump. The third circulation pump is then activated, circulating the coolant from the second cooling circuit.

[0014] The advantage is that connecting both cooling circuits with lockable connections achieves redundancy for both systems. In particular, this system avoids the need to create separate redundancy for each system. The additional piping is smaller and requires less maintenance than an additional pump, thus ensuring that reliability is not reduced while saving space and effort.

[0015] Although the main focus is on the application case where the first waste heat-generating device is an energy storage device and the second waste heat-generating device is a fuel cell device, and this is also a preferred embodiment, the invention is not limited to this.

[0016] Alternatively, the first waste heat-generating device can be a device for providing cold water and the second waste heat-generating device can be the drive motor.

[0017] Alternatively, the first waste heat-generating device can be a device for providing cold water and the second waste heat-generating device can be a power generator.

[0018] Alternatively, the first waste heat-generating device can be a device for providing cold water and the second waste heat-generating device can be an energy storage device.

[0019] Alternatively, the first waste heat-generating device can be an energy storage device and the second waste heat-generating device can be a diesel generator.

[0020] In a further embodiment of the invention, the first cooling circuit comprises a first heat exchanger. The first heat exchanger transfers heat from the coolant of the primary circuit to a secondary circuit. This secondary cooling circuit can, for example, be supplied with ambient water on the secondary side via a first heat exchanger pump. This is then an open secondary cooling circuit. Furthermore, the second cooling circuit comprises a second heat exchanger. The second heat exchanger transfers heat from the coolant of the primary circuit to a secondary circuit. This secondary cooling circuit can, for example, be supplied with ambient water on the secondary side via a second heat exchanger pump. This is then an open secondary cooling circuit.The use of closed cooling circuits is advantageous because, especially in the area of ​​fuel cells, the coolant has very well-defined properties and problems such as adhesion or growth of biological systems in the cooling circuit are avoided.

[0021] Alternatively, it can be provided that an additional, closed coolant circuit is arranged between the respective primary cooling circuits and the respective secondary circuits, which transfers the waste heat.

[0022] In a further embodiment of the invention, the inlet of the second heat exchanger can be connected to the inlet of the first heat exchanger. This makes both systems connectable to the ambient water if one of the pumps in one of the two systems fails and the pumps are located upstream of the heat exchangers.

[0023] In a further embodiment of the invention, the outlet of the second heat exchanger can be connected to the outlet of the first heat exchanger. This makes both systems connectable for the ambient water if one of the pumps in one of the two systems fails and the pumps are located downstream of the heat exchangers.

[0024] In a further embodiment of the invention, the submarine has a third heat exchanger pump, either as an alternative or in addition to the ability to connect the two ambient water systems. The third heat exchanger pump can be connected alternately to the first or the second heat exchanger. The third heat exchanger pump is thus configured so that it can replace either the first or the second heat exchanger pump and can preferably be connected in parallel to the heat exchanger pump to be replaced by opening appropriate valves.

[0025] In a further embodiment of the invention, a coolant degassing device is arranged in parallel to the second waste heat-generating device in the first cooling circuit. The volume flow rate through the coolant degassing device is particularly preferably adjustable. If, after the failure of the first circulation pump, the second circulation pump is connected to the first cooling circuit, coolant enters the first cooling circuit, which is typically not degassed, as this is not necessary for the first waste heat-generating device. Although this is only a small volume, it can be advantageous to increase the volume flow rate through the coolant degassing device, at least temporarily, in order to remove the dissolved gases as quickly as possible.

[0026] In a further embodiment of the invention, the third circulation pump is smaller than the first and second circulation pumps. This saves space and weight. Furthermore, this third circulation pump is intended only for emergencies, in which the requirements for the third circulation pump can be easily reduced by further reducing the power output of the first waste heat-generating device.

[0027] In a further aspect, the invention relates to a method for converting a submarine with a first waste heat-generating device based on lead-acid batteries into an energy storage device with redundant cooling circuits according to the previously described invention. In the conversion process, an acid recirculation compressor is replaced by a suitable third recirculation pump, thus utilizing the space and weight saved by removing the acid recirculation compressor. The acid recirculation compressor is typically relatively small, significantly smaller than a recirculation pump for a coolant circuit. The third recirculation pump is connected to the second cooling circuit. Additionally, the first cooling circuit connection, the second cooling circuit connection, the first switching valve, the second switching valve, the third switching valve, and the fourth switching valve are installed.This makes it relatively easy to produce a submarine according to the invention during a conversion.

[0028] The submarine according to the invention is explained in more detail below with reference to an embodiment shown in the drawing. Fig. 1 schematic representation of a first embodiment Fig. 2 schematic representation of a second embodiment

[0029] In Fig. 1 The corresponding part of a submarine according to the invention is shown schematically. The submarine has a fuel cell device 20 with a fuel cell cooling circuit 40. A coolant degassing device 190 is arranged parallel to the fuel cell device, as can be seen, for example, in DE 10 2020 202 024 or DE 10 2020 206 554. The flow direction of the coolant in the fuel cell cooling circuit 40 is shown in the Fig. 1 indicated by arrows. The fuel cell cooling circuit 40 further comprises a first circulation pump 50 for circulating the coolant and a first heat exchanger 140. In particular, for starting up the fuel cell device 20, the coolant flow can be diverted past the first heat exchanger 140 via the start-up valve 200.

[0030] Furthermore, the submarine has an energy storage device 10, which is cooled via an energy storage cooling circuit 30. The energy storage cooling circuit 30 includes a second circulation pump 60 and a second heat exchanger 150. In order to maintain cooling in the event of a failure of the second circulation pump 60, a third circulation pump 70 is installed in parallel to the second circulation pump 60; however, this third pump has, for example, only half the flow rate of the second circulation pump 60.

[0031] To transfer heat to the boat's surroundings, the first heat exchanger 140 is supplied with water from the environment outside the hull 210, for example, as part of the pressure hull, via a first heat exchanger pump 160. Similarly, the second heat exchanger 150 is supplied with water from the environment outside the hull 210 via a second heat exchanger pump 170. The arrows indicate an example flow direction; however, the direction of rotation of the two heat exchanger pumps 160 and 170 could also be reversed, in which case the flow directions would be reversed.

[0032] To achieve redundancy for the first circulation pump 50, the submarine has a first cooling circuit connection 80 and a second cooling circuit connection 90. The first cooling circuit connection 80 connects the fuel cell cooling circuit 40 upstream of the first circulation pump 50 with the energy storage cooling circuit 30 upstream of the second circulation pump 60 and downstream of the branch to the third circulation pump 70. The second cooling circuit connection 90 connects the fuel cell cooling circuit 40 downstream of the first circulation pump 50 with the energy storage cooling circuit 30 downstream of the second circulation pump 60 and upstream of the merger with the third circulation pump 70.

[0033] To selectively activate and deactivate these cooling circuit connections 80 and 90, a first switching valve 100 is arranged in the first cooling circuit connection 80, and a second switching valve 110 is arranged in the second cooling circuit connection 90. Furthermore, a third switching valve 120 is arranged in the energy storage cooling circuit 30 upstream of the connection with the first cooling circuit connection 80 and downstream of the branch to the third circulation pump 70. A fourth switching valve 130 is also arranged in the energy storage cooling circuit 30 downstream of the connection with the second cooling circuit connection 90 and upstream of the merger with the third circulation pump 70.

[0034] Normally, the first changeover valve 100 and the second changeover valve 110 are closed, while the third changeover valve 120 and the fourth changeover valve 130 are open. If the first circulation pump 50 fails, the first changeover valve 100 and the second changeover valve 110 open, and the third changeover valve 120 and the fourth changeover valve 130 close. Now, the coolant of the fuel cell cooling circuit 40 can be circulated by the second circulation pump 60, and the coolant of the energy storage cooling circuit 30 can be circulated by the third circulation pump 70, without mixing. Only the small volume located in the area of ​​the second circulation pump 60 between the switching valves 100, 110, 120, 130 enters the fuel cell cooling circuit 40. This will lead to a short-term increase in the amount of gas discharged in the coolant degassing device 190.

[0035] The in Fig. 2 The second embodiment shown differs from the one in Fig. 1 The first embodiment shown differs in that the first waste heat-generating device is a device for providing cold water 230 and the second waste heat-generating device is the drive motor 220. Furthermore, both embodiments are identical. Reference sign

[0036] 10 Energy storage device 20 Fuel cell device 30 Energy storage cooling circuit 40 Fuel cell cooling circuit 50 First circulation pump 60 Second circulation pump 70 Third circulation pump 80 First cooling circuit connection 90 Second cooling circuit connection 100 First changeover valve 110 Second changeover valve 120 Third changeover valve 130 Fourth changeover valve 140 First heat exchanger 150 Second heat exchanger 160 First heat exchanger pump 170 Second heat exchanger pump 180 Connection valve 190 Coolant degassing device 200 Starting valve 210 Side panel 220 Drive motor 230 Chilled water supply device

Claims

1. Submarine with a first waste heat generating device and a second waste heat generating device, wherein the first waste heat generating device is cooled via a second cooling circuit, wherein the second waste heat generating device is cooled via a first cooling circuit, wherein the first cooling circuit has a first circulation pump (50), wherein the second cooling circuit has a second circulation pump (60), wherein the second cooling circuit comprises a third circulation pump (70), wherein the third circulation pump (70) is arranged in parallel with the second circulation pump (60), wherein the submarine comprises a first cooling circuit connection (80), wherein the first cooling circuit connection connects the first cooling circuit upstream of the first circulation pump (50) to the second cooling circuit upstream of the second circulation pump (60) and downstream of the branch to the third circulation pump (70), characterised in that the submarine comprises a second cooling circuit connection (90), wherein the second cooling circuit connection (90) connects the first cooling circuit after the first circulation pump (50) to the second cooling circuit after the second circulation pump (60) and before the junction from the third circulation pump (70), wherein a first changeover valve (100) is arranged in the first cooling circuit connection (80) (100) is arranged in the first cooling circuit connection (80), wherein a second switchover valve (110) is arranged in the second cooling circuit connection (90), wherein a third switchover valve (120) is arranged in the second cooling circuit before the connection to the first cooling circuit connection (80) and after the branch to the third circulation pump (70) (120) is arranged in the second cooling circuit, a fourth switchover valve (130) is arranged in the third cooling circuit after the connection to the second cooling circuit connection (90) and before the junction from the third circulation pump (70).

2. Submarine according to claim 1, characterised in that the first waste heat generating device is an energy storage device (10) and the second waste heat generating device is a fuel cell device (20), wherein the second cooling circuit is an energy storage cooling circuit (30), wherein the first cooling circuit is a fuel cell cooling circuit (40).

3. Submarine according to claim 2, characterised in that a coolant degassing device (190) is arranged in parallel with the fuel cell device (20) in the fuel cell cooling circuit (40).

4. Submarine according to one of the preceding claims, characterised in that the first cooling circuit has a first heat exchanger (140), wherein the first heat exchanger (140) is cooled by ambient water via a first heat exchanger pump (160), wherein the second cooling circuit has a second heat exchanger (150), wherein the second heat exchanger (150) is cooled by ambient water via a second heat exchanger pump (170).

5. Submarine according to claim 4, characterised in that the inlet of the second heat exchanger (150) can be connected to the inlet of the first heat exchanger (140).

6. Submarine according to claim 4, characterised in that the submarine has a third heat exchanger pump, wherein the third heat exchanger pump can be connected alternately to the first heat exchanger (140) or the second heat exchanger (150).

7. Submarine according to one of the preceding claims, characterised in that the capacity of the third circulation pump (70) is lower than the capacity of the first circulation pump (50) and the second circulation pump (60).

8. Method for converting a submarine to a submarine according to one of the preceding claims with an energy storage device (10) based on lead accumulators to an energy storage device (10) based on lithium accumulators with redundant cooling circuits, characterised in that the acid circulation compressor is replaced by a third circulation pump (70), wherein the third circulation pump (70) is additionally connected to the energy storage cooling circuit (30), wherein the first cooling circuit connection (80), the second cooling circuit connection ( ) (90), the first changeover valve (100), the second switch valve (110), the third switch valve (120) and the fourth switch valve (130) are also installed.