Method for operating a ship's cooling system

Abstract

Method for operating a cooling system (10) of a ship, wherein the cooling system (10) comprises a seawater subsystem (11) with a seawater pump (14a, 14b) and at least one first cooling water circuit (13); wherein the seawater subsystem (11) and the first cooling water circuit (13) are coupled via a heat exchanger (12) such that in the region of the heat exchanger (12) the cooling water of the first cooling water circuit (13) is cooled by the seawater of the seawater subsystem (11); and wherein the first cooling water circuit (13) has a bypass (17) to the heat exchanger (12) coupling the seawater subsystem (11) and the first cooling water circuit (13) and a control valve (18) whose position determines which portion of the cooling water of the first cooling water circuit (13) is routed through the heat exchanger (12) and which portion of the cooling water of the first cooling water circuit (13) is routed through the bypass (17), wherein the position of the control valve (18) is regulated such thatthat a supply cooling water temperature, which is established by mixing the cooling water portion routed through the heat exchanger (12) and the cooling water portion routed through the bypass (17), corresponds to a corresponding setpoint. The speed of the seawater pump (14a, 14b) of the seawater subsystem (11) is controlled depending on the position of the control valve (18) of the first cooling water circuit (13), the position of which determines which cooling water portion of the first cooling water circuit (13) is routed through the heat exchanger (12) and which cooling water portion of the first cooling water circuit (13) is routed through the bypass (17), wherein the first cooling water circuit (13) comprises a cooling water pump (28a, 28b), a low-temperature charge air cooler (26), at least one cooler (32) for cooling at least one further assembly, and another control valve (30).via whose switching position a cooling water portion of the first cooling water circuit (13) routed via the low-temperature charge air cooler (26) can be adjusted, The speed of the cooling water pump (28a, 28b) of the first cooling water circuit (13) is regulated depending on the position of the control valve or each control valve (18, 30) of the first cooling water circuit (13).

Description

[0001] The invention relates to a method for operating a cooling system of a ship according to the preamble of claim 1.

[0002] The basic structure and operation of a ship's cooling system are well known to the expert in question from practical experience and are schematically represented in Fig. Figure 6 shows that a cooling system 10 of a ship comprises a seawater subsystem 11 with a seawater pump 14 and at least one cooling water circuit 13 with a cooling water pump 28. The seawater subsystem 11 and the cooling water circuit 13 are coupled via a heat exchanger 12 such that, in the region of the heat exchanger 12, the cooling water of the first cooling water circuit 13 is cooled by the seawater of the seawater subsystem 12. The first cooling water circuit 13 has a bypass 17 to the heat exchanger 12, which couples the seawater subsystem 11 and the first cooling water circuit 13, and a control valve 18, the position of which determines what portion of the cooling water of the first cooling water circuit 13 is routed through the heat exchanger 12 and what portion of the cooling water of the first cooling water circuit 13 is routed through the bypass 17.The position of the control valve 18 is changed via an actuator 19 and determined by a controller 41 such that the supply cooling water temperature, which is achieved by mixing the cooling water portion routed via the heat exchanger 12 and the cooling water portion routed via the bypass 17, corresponds to a setpoint value. The cooling water can then be supplied to a component 42 to be cooled at this supply cooling water temperature. This is the case with cooling water systems 10 known from practice according to... Fig. According to this, a sensor 43 measures the actual value of the supply cooling water temperature, and depending on this value, the controller 41 influences the position of the control valve 18 via the actuator 19. In typical ship cooling systems, the seawater pump 14 of the seawater subsystem 11 and the cooling water pump 28 of the first cooling water circuit 13 are operated at full speed. This results in a relatively high energy consumption.

[0003] The JP 2002 - 274 493 A, the KR 10 2010 0 080 566 A and the KR 10 2012 0 015 402 A reveal cooling systems of a ship.

[0004] Based on this, the present invention aims to create an energy-saving method for operating a ship's cooling system.

[0005] This problem is solved by a method for operating a ship's cooling system according to claim 1. According to the invention, the rotational speed of the seawater pump of the seawater subsystem is controlled depending on the position of the control valve of the first cooling water circuit, the position of which determines what proportion of the cooling water of the first cooling water circuit is routed through the heat exchanger and what proportion is routed through the bypass. The primary control variable for regulating the rotational speed of the seawater pump of the seawater subsystem is therefore the position of that control valve of the first cooling water circuit which determines what proportion of the cooling water of the first cooling water circuit is routed through the heat exchanger and what proportion is routed through the bypass.The control system for this control valve of the first cooling water circuit, which is known from practical experience and depends on the actual value of the supply cooling water temperature, remains active. The control concept according to the invention has the advantage that energy can be saved by varying the speed of the seawater pump. The control concept is particularly suitable for use in cooling systems where the heat exchanger that connects the seawater subsystem and the first cooling water circuit is not designed as a central heat exchanger.

[0006] Preferably, the speed of the seawater pump in the seawater subsystem is regulated according to the position of this control valve in the first cooling water circuit such that the proportion of cooling water from the first cooling water circuit passing through the heat exchanger is maximized and thus approximated to a corresponding setpoint. When as much cooling water as possible passes through the heat exchanger, i.e., when the proportion of cooling water from the first cooling water circuit passing through the heat exchanger is maximized, the speed of the seawater pump can be reduced further, resulting in greater energy savings.

[0007] According to the invention, the first cooling water circuit comprises a cooling water pump, a low-temperature charge air cooler, at least one radiator for cooling at least one further assembly, and a further control valve, the switching position of which allows adjustment of the cooling water portion of the first cooling water circuit that is routed through the low-temperature charge air cooler. The speed of the cooling water pump of the first cooling water circuit is regulated depending on the position of the control valve(s) of the first cooling water circuit, preferably such that the cooling water portion of the first cooling water circuit routed through the low-temperature charge air cooler is maximized and thus approximated towards a corresponding setpoint.In this advantageous further development, in addition to the speed of the seawater pump, the speed of the cooling water pump of the first cooling circuit is also regulated in order to reduce its speed as much as possible and thereby save energy. Furthermore, when the second and first cooling water circuits are coupled via their respective heat exchangers, the speed of the cooling water pump of the first cooling water circuit is additionally regulated depending on the position of the control valve of the second cooling water circuit. This feature also allows for effective control of the speed of the cooling water pump of the first cooling water circuit.

[0008] In a further advantageous embodiment, the speed of the seawater pump of the seawater subsystem is controlled depending on the temperature of the seawater downstream of the heat exchanger, preferably such that when the temperature of the seawater downstream of the heat exchanger exceeds a limit value, the speed of the seawater pump is increased so that the temperature of the seawater becomes lower than or equal to the limit value. This prevents salt deposits from forming in the cooler or in parts of the cooling system.

[0009] In a further advantageous embodiment, the cooling system comprises a second cooling water circuit, wherein the second cooling water circuit and the seawater subsystem or the second cooling water circuit and the first cooling water circuit are coupled via a heat exchanger, in the region of which the cooling water of the second cooling water circuit is cooled by the seawater of the seawater subsystem or the cooling water of the first cooling water circuit. The second cooling water circuit comprises a bypass to the heat exchanger coupling the second cooling water circuit and the seawater subsystem or the second cooling water circuit and the first cooling water circuit, and a control valve whose position determines what portion of the cooling water of the second cooling water circuit is routed through the heat exchanger and what portion of the cooling water of the second cooling water circuit is routed through the bypass.The position of the control valve of the second cooling water circuit is determined such that the return cooling water temperature upstream of the heat exchanger corresponds to a specific setpoint. The speed of the seawater pump of the seawater subsystem is further regulated depending on the position of the control valve of the second cooling water circuit, preferably such that, on the one hand, the cooling water fraction of the first cooling water circuit passing through the heat exchanger of the first cooling water circuit is maximized and thus approximated to a specific setpoint, and, on the other hand, the cooling water fraction of the second cooling water circuit passing through the heat exchanger of the second cooling water circuit is maximized and thus approximated to a specific setpoint.This further development of the invention has the advantage that the speed of the seawater pump can be controlled even more advantageously and the potential for energy savings while maintaining good cooling can be exploited even better.

[0010] According to one variant, the first cooling water circuit comprises a cooling water pump, a low-temperature charge air cooler, a high-temperature charge air cooler, at least one radiator for cooling at least one further assembly, and a further control valve whose switching position allows adjustment of the proportion of cooling water routed through the low-temperature charge air cooler and the proportion routed through the high-temperature charge air cooler. The speed of the cooling water pump of the first cooling water circuit is then regulated depending on the position of this control valve, preferably such that the proportion of cooling water routed through the high-temperature charge air cooler is maximized and thus approximated towards a corresponding target value.This variant also allows for effective control of the speed of the seawater pump as well as the speed of the cooling water pump of the first cooling water circuit in order to achieve the best possible energy savings while maintaining the necessary cooling function.

[0011] Preferred embodiments of the invention are described in the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail with reference to the drawing, without being limited thereto. The drawing shows: Fig. 1: a block diagram of a first cooling system of a ship to illustrate the invention; Fig. 2: a block diagram of a second cooling system of a ship to illustrate the invention; Fig. 3: a block diagram of a third cooling system of a ship to illustrate the invention; Fig. 4: a block diagram of a fourth cooling system of a ship to illustrate the invention; Fig. 5: a block diagram of a fifth cooling system of a ship to illustrate the invention; Fig. 6. A block diagram to illustrate the state of the art; and Fig. 7 A block diagram to further illustrate the invention.

[0012] Fig. Figure 1 shows a section of a cooling system 10 of a ship in the area of ​​a seawater subsystem 11 of the cooling system 10 and a first cooling water circuit 13 of the cooling system 10 coupled to the seawater subsystem 11 via a heat exchanger 12.

[0013] The seawater subsystem 11 has a seawater pump or at least one seawater pump, in the illustrated embodiment two seawater pumps 14a, 14b, each driven by an actuator 15a, 15b.

[0014] Seawater can be drawn from seawater tanks 16a, 16b via the seawater pumps 14a, 14b of the seawater subsystem 11 and conveyed via the heat exchanger 12, which couples the seawater subsystem 11 with the first cooling water circuit 13. Cooling water is conveyed in the first cooling water circuit 13 to Fig. The first cooling water circuit 13 (not shown) is used to cool the ship's components, with the cooling water in the area of ​​the heat exchanger 12 being cooled by the seawater of the seawater subsystem 11, which also passes through the heat exchanger 12. The first cooling water circuit 13 has a bypass 17 to which the seawater subsystem 11 and the first cooling water circuit 13 are connected, as well as a control valve 18, which in the illustrated embodiment is designed as a three-way control valve and whose position can be changed by an actuator 19. The position of the control valve 18 of the first cooling water circuit 13 determines what proportion of the cooling water in the first cooling water circuit 13 passes through the heat exchanger 12 and what proportion passes through the bypass 17.In the area of ​​the control valve 18, cooling water routed via the heat exchanger 12 and cooling water routed via the bypass 17 are mixed, whereby an actual value of a supply cooling water temperature is established downstream of the control valve 18, depending on the mixture of the cooling water portion routed via the heat exchanger 12 and the cooling water portion routed via the bypass 17. The position of the control valve 18 is adjusted by the actuator 19 such that the actual value of the supply cooling water temperature corresponds to a corresponding predetermined setpoint value.

[0015] According to the invention, the rotational speed of the seawater pump is controlled. Fig. 1. The rotational speed of the seawater pump 14a and / or the rotational speed of the seawater pump 14b is regulated, depending on the position of the control valve 18 of the first cooling water circuit 13, the position of which determines what proportion of the cooling water of the first cooling water circuit 13 is routed via the heat exchanger 12 and what proportion of the cooling water of the first cooling water circuit 13 is routed via the bypass 17. The primary control variable, depending on which the rotational speed of the pump(s) is regulated, is... Fig. The position of valve 18 is therefore used to control the seawater pump 14a and / or 14b shown in Figure 1. The control of the control valve 18, which is known from practice, i.e. the control of the actual value of the supply cooling water temperature via the control valve 18, remains active.

[0016] The speed of the seawater pump 14a and / or 14b is regulated depending on the position of the control valve 18 of the first cooling water circuit 13 in such a way that the cooling water fraction of the first cooling water circuit 13, which is routed via the heat exchanger 12, is as large as possible and thus approximated towards a corresponding target value.

[0017] In this context, it should be mentioned that the cooling water fraction of the first cooling water circuit 13, which is routed through the heat exchanger 12, is typically set to a maximum value of, for example, 90%, so that a minimum amount of cooling water, for example, 10%, is always routed through the bypass 17. The speed of the seawater pump 14a and / or 14b is adjusted or controlled, depending on the position of the control valve 18, such that the cooling water fraction of the first cooling water circuit routed through the heat exchanger 12 is adjusted towards its maximum value and thus the corresponding target value, so that as much cooling water as possible from the first cooling water circuit 13 is always routed through the heat exchanger 12, but a minimum amount of cooling water always flows through the bypass 17.

[0018] By appropriately reducing the speed of the seawater pump 14a and / or 14b, the amount of seawater passed through the heat exchanger 12 is reduced, thereby indirectly increasing the proportion of cooling water in the first cooling water circuit 13 that passes through the heat exchanger 12.

[0019] In the above-mentioned control of the speed of the seawater pump 14a and / or 14b, the temperature of the seawater downstream of the heat exchanger 12 can also be taken into account. If the temperature of the seawater downstream of the heat exchanger 12 exceeds a predetermined limit, the speed of the seawater pump 14a and / or 14b is increased so that the temperature of the seawater downstream of the heat exchanger 12 then becomes less than or equal to this limit.

[0020] As already explained, shows Fig. 1 Two seawater pumps 14a, 14b in the seawater subsystem 11. It can be provided that both seawater pumps 14a, 14b are designed as variable-speed pumps, in which case the speed of both seawater pumps 14a and 14b can be regulated in the manner described above. In contrast, it is also possible that one of the seawater pumps 14a or 14b is designed as a constant-speed pump, in which case only the speed of the other seawater pump 14b or 14a is regulated in the manner described above.

[0021] Fig. Figure 2 shows a modification of the cooling system 10. Fig. 1, where the cooling system is 10 of the Fig. 2 in addition to the first cooling water circuit 13, a second cooling water circuit 20 is included. In the exemplary embodiment of the Fig. 2 The second cooling water circuit 20 is also coupled to the seawater subsystem 12 via a heat exchanger 21, such that in the area of ​​the heat exchanger 21 the cooling water of the second cooling water circuit 20 is cooled by the seawater of the seawater subsystem 12, wherein the two heat exchangers 12, 21, via which the two cooling water circuits 13, 20 are coupled to the seawater subsystem 12, are connected in series such that the seawater of the seawater subsystem 11 is first passed through the heat exchanger 12, which couples the seawater subsystem 11 and the first cooling circuit 13, and subsequently through the heat exchanger 21, which couples the seawater subsystem 11 and the second cooling circuit 20.

[0022] The second cooling circuit 20, like the first cooling circuit 13, has a bypass 22 and a control valve 23. The position of the control valve 23 of the second cooling circuit 20 can be changed by an actuator. The position of the control valve 23 of the second cooling circuit 20 determines what proportion of the cooling water of the second cooling circuit 20 is routed through the heat exchanger 21 and what proportion of the cooling water of the second cooling circuit 20 is routed to the heat exchanger 21 via the bypass 22. The position of the control valve 23 is preferably determined such that the return temperature upstream of the heat exchanger 21 of the cooling water of the second cooling circuit 20 corresponds to a specific, predetermined setpoint.

[0023] In the exemplary embodiment of the Fig. 2 The speed of the seawater pump 14a and / or 14b is determined not only depending on the position of the control valve 19 of the first cooling water circuit 13, but also depending on the position of the control valve 23 of the second cooling water circuit 20.

[0024] The speed of the seawater pump 14a and / or 14b is regulated in such a way that, on the one hand, the cooling water fraction of the first cooling water circuit 13, which is guided via the heat exchanger 12 of the first cooling water circuit 13, is made as large as possible and thus approximates the corresponding target value, and that, on the other hand, the cooling water fraction of the second cooling water circuit 20, which is guided via the heat exchanger 21 of the second cooling water circuit 20, is made as large as possible and thus approximates a corresponding target value.

[0025] As already described in connection with the first cooling water circuit 13, it is also intended for the second cooling water circuit 20 to always carry a minimum amount of cooling water via the bypass 22, so that the corresponding target value for the cooling water fraction of the second cooling water circuit 20 carried via the heat exchanger 21 is less than 100%.

[0026] Even in the variant of Fig. 2, in which the speed of the seawater pump 14a and / or the seawater pump 14b is controlled depending on the position of the control valves 19 and 23, the temperature of the seawater is taken into account when controlling the speed of the seawater pump 14a and / or the seawater pump 14b, specifically the temperature of the seawater downstream of the two heat exchangers 12 and 21, i.e., immediately downstream of heat exchanger 21. Then, if this seawater temperature exceeds a limit value, the speed of the seawater pump 14a and / or the seawater pump 14b is increased so that the seawater temperature again falls below or equals the respective limit value.

[0027] Fig. Figure 3 shows a further development of the cooling system 10 of the Fig. 2, wherein in Fig. 3 in addition to those in Fig. The two assemblies shown are further assemblies, in particular an internal combustion engine 25 to be cooled, to which a low-temperature charge air cooler 26 and a high-temperature charge air cooler 27 are assigned. The low-temperature charge air cooler 26 is integrated into the first cooling circuit 13 and the high-temperature charge air cooler 27 into the second temperature circuit 20. Further assemblies of the first cooling water circuit 13 are shown. Fig. 2 a cooling water pump, namely at least one cooling water pump, and in the illustrated embodiment two cooling water pumps 28a, 28b, each driven by an actuator 29a, 29b and serving to circulate the cooling water in the first cooling water circuit 13. Furthermore, the figure shows Fig. 3 as a further component of the first cooling water circuit 13, a further control valve 30, the position of which is influenced by an actuator 31, as well as a further cooler 32, which is designed in particular as a lubricating oil cooler for cooling the lubricating oil for the internal combustion engine 25. As a further component of the second cooling circuit 20, Fig. 3 a cooling water pump 33 with an actuator 39, which serves to circulate the coolant in the second cooling circuit 20. In Fig. 3. The speed of the seawater pump 14a and / or 14b is regulated as described in connection with Fig. 2 described depending on the position of the switching valve 18 of the first cooling water circuit 13 as well as depending on the position of the switching valve 23 of the second cooling water circuit 20 as well as possibly depending on the temperature of the seawater downstream of the heat exchanger 21.

[0028] In Fig. 3. Furthermore, the speed of the cooling water pump 28a and / or 28b is regulated, depending on the position of the two switching valves 18 and 30 of the first cooling water circuit 13. As already explained, the position of the control valve 18 is determined such that a desired actual value of the supply cooling water temperature is established downstream of the control valve 18. The position of the control valve 30 adjusts the portion of the cooling water in the first cooling water circuit 13 that passes through the low-temperature charge air cooler 26, as well as the portion that bypasses the low-temperature charge air cooler 26. Downstream of the control valve 30, the cooling water portions that pass through and bypass the low-temperature charge air cooler 26 are mixed again before being directed via the cooler 32, which serves as a lubricating oil cooler, to cool the lubricating oil.

[0029] The rotational speed of the coolant pump 28a and / or 28b is determined based on the switching position of the switching valves 18 and 30 in such a way that as much water as possible is routed through the low-temperature charge air cooler 26, thus maximizing the proportion of coolant from the first cooling circuit 13 routed through the low-temperature charge air cooler 26 and thereby approximating it to a corresponding target value. However, not the entire quantity of coolant pumped by the coolant pump 28a and / or 28b is routed through the low-temperature charge air cooler 26. Instead, a minimum proportion of this coolant from the first cooling circuit 13 is always routed to the low-temperature charge air cooler 26 via a bypass 34.By regulating the speed of the coolant pump 28a and / or 28b of the first coolant circuit 13, the speed of the coolant pump 28a and / or 28b is reduced until the amount of coolant or the proportion of coolant of the first coolant circuit 13 that passes through the low-temperature charge air cooler 26 corresponds to a maximum value and thus to its corresponding target value.

[0030] When regulating the speed of the cooling water pump 28a and / or 28b, the temperature of the medium cooled in the radiator 32 is also taken into account. Fig. 3 of the lubricating oil cooled in the cooler 32 is taken into account. Should the temperature of the lubricating oil leaving the cooler 32 exceed a limit value, the speed of the cooling water pump 28a and / or 28b is increased until the temperature of the lubricating oil leaving the cooler 32 falls below or equals this limit value. In addition to the cooler 32, 13 further coolers for cooling a medium can be installed in the first cooling circuit, for example, a cooler for an auxiliary drive unit and / or a cooler for an air conditioning system and / or a cooler for an injector cooling system.The temperature of each medium to be cooled in the respective cooler is preferably monitored and compared with a corresponding limit value, whereby if a corresponding limit value is exceeded, the speed of the coolant pump 28a and / or 28b is increased in order to ensure proper cooling of the respective medium to be cooled in the area of ​​the respective cooler.

[0031] In Fig. 3. Both cooling water pumps 28a and 28b can be variable-speed cooling water pumps, in which case their speed can be regulated as described above. Alternatively, it is also possible that only one of these cooling water pumps 28a or 28b is variable-speed, while the other cooling water pump 28b and 28s is a constant-speed pump. In this case, only the variable-speed cooling water pump is regulated as described above.

[0032] In Fig. 3 Furthermore, the speed of the cooling water pump 33 of the second cooling water circuit 20 can be regulated, depending on the cooling requirement of the internal combustion engine 25.

[0033] Fig. Figure 4 shows a modification of the cooling system 10. Fig. 3, where the cooling system is 10 of the Fig. 4 of the cooling system 10 of the Fig. 3 differs in that the second heat exchanger 21, which serves to cool the cooling water of the second cooling circuit 20, is not coupled to the seawater subsystem 11, but rather to the first cooling circuit 13. Thus, Fig. It can be seen from Figure 4 that, downstream of the cooling water pumps 28a and 28b, coolant from the first cooling circuit 13 is supplied to the heat exchanger 21 via line 35 in order to cool the cooling water of the second cooling circuit 20 in the area of ​​the heat exchanger 21. In the area of ​​the return of the first cooling circuit 13, this cooling water from the first cooling circuit 13, which has been routed via the heat exchanger 21, is returned to the cooling circuit 13, specifically downstream of the radiator 32 and upstream of the heat exchanger 12, namely upstream of the bypass 17. The embodiment shown applies to all other assemblies. Fig. 4 with the exemplary embodiment of the Fig. 3 agree, so to avoid unnecessary repetition, reference is made to the above statements. Regarding cooling system 10 of the Fig. 4. The speed of the seawater pumps 14a and / or 14b of the seawater subsystem 11 is preferably controlled as described in connection with Fig. 1 described.

[0034] In the cooling water system 10 of the Fig. 4. The speed of the coolant pump 28a and / or 28b of the first coolant circuit 13 is controlled not only by the switching position of the switching valves 19 and 30 of the first coolant circuit 13, but also by the switching position of the control valve 23 of the second coolant circuit 20. The speed of the coolant pump 28a and / or 28b is adjusted so that as much coolant as possible, and thus the highest possible proportion of coolant from the second coolant circuit 20, is routed through the heat exchanger 21. To achieve this, the speed of the coolant pump 28a and / or 28b of the first coolant circuit 13 is reduced accordingly, so that less coolant from the first coolant circuit 13 is routed through the heat exchanger 21, ultimately increasing the amount of coolant from the second coolant circuit 20 passing through the heat exchanger 21.Preferably, a minimal amount of coolant from the second cooling circuit 20 is routed via bypass 22 of the second cooling circuit 20. Therefore, the speed of the coolant pump 28a and / or 28b is reduced only to the extent that the coolant flow rate of the second cooling circuit 20 via the heat exchanger 21 reaches its corresponding target value, which is less than 100%, and thus maintains a minimal amount of coolant flow via bypass 22. The speed of the coolant pump 33 of the second cooling circuit 20 can again be regulated according to the requirements of the internal combustion engine 25.

[0035] Fig. Figure 5 shows another modification of a ship's cooling water system, where the cooling water system 10 is the Fig. 5 of the cooling water system 10 of the Fig. 4 differs in that only a single cooling water circuit, i.e., first cooling water circuit 13, is present, so that the separate second cooling water circuit 20 is omitted. In accordance with the embodiments described above, the supply cooling water temperature downstream of the control valve 18 is set by directing the cooling water of the first cooling water circuit 13 partly via the heat exchanger 12 and partly via the bypass 17 to the heat exchanger 12, wherein the heat exchanger 12 couples the seawater subsystem 11 for cooling the cooling water of the first cooling circuit 13 with the first cooling circuit 13.

[0036] The cooling water pump 28a and / or 28b pumps the cooling water of the first cooling water circuit 13 from this supply line, the switching position of the control valve 30 determining what portion of the cooling water is routed through the low-temperature charge air cooler 26 and what portion bypasses the low-temperature charge air cooler 26 and passes through the radiator 32. Downstream of the radiator 32, the cooling water of the first cooling circuit 13 is divided into a portion that is routed through the high-temperature charge air cooler 27 by means of the pump 36, and a portion that bypasses the high-temperature charge air cooler 27 and is routed directly into the return line towards the heat exchanger 12.A control valve 37, which is adjustable by an actuator 38, determines these two cooling water fractions: the cooling water fraction that is circulated over the high-temperature charge air cooler 27 by means of the pump 36, and the cooling water fraction that bypasses the high-temperature charge air cooler 27. The speed of the seawater pump 14a and / or 14b of the seawater subsystem 11 is controlled in [the relevant section / section]. Fig. 5 as in connection with Fig. 1 described.

[0037] The speed of the cooling water pump 28a and / or 28b of the first cooling circuit 13 is regulated depending on the position of the control valves 18 and / or 30 and / or 37, such that, by adjusting the speed of the cooling water pump 28a and / or 28b accordingly, it is ensured that as much cooling water as possible, and thus as high a cooling water fraction as possible, is routed through the high-temperature charge air cooler 27. However, a minimal amount of cooling water is also routed past the high-temperature charge air cooler 27. The speed of the cooling water pump 36 can be regulated according to the requirements of the internal combustion engine 25.

[0038] The cooling water pumps 28a, 28b, 33 and 36 are each electrically driven. The flow rate of the respective pump can be regulated by appropriately changing the speed of the corresponding actuators 29a, 29b, 39, 40. This is preferred.

[0039] It should be noted that mechanically driven cooling water pumps 28a, 28b, 33, 36 can also be used, whereby throttles are integrated into the cooling circuit which are adjusted accordingly via the control system.

[0040] Referring to Fig. Examples of embodiments described in 1 to 5 Fig. Numbers 1 through 5 have in common that, as in Fig.Figure 7 shows that the control of the position of the control valve 18, known from practical experience, is maintained depending on the actual value of the supply cooling water temperature. Depending on the position of the control valve 18 of the first cooling water circuit 13, which determines what proportion of the cooling water in the first cooling water circuit 13 is routed through the heat exchanger 12 and what proportion is routed through the bypass 17, the controller 41 regulates the speed of one or at least one seawater pump 14. Furthermore, the controller 41 preferably also regulates the speed of one or at least one cooling water pump 28 of the cooling water circuit 13, also depending on the position of the control valve 18. The speed of the seawater pump 14 and / or the cooling water pump 28 can be reduced, thereby saving energy. The process is fully automatic. Reference symbol list 10 Cooling system 11 Seawater subsystem 12 heat exchangers 13 first cooling water circuit 14 Seawater pump 14a Seawater pump 14b Seawater pump 15 Actuator 15a Actuator 15b Actuator 16a Seawater tank 16b Seawater tank 17 Bypass 18 Control valve 19 Actuator 20 second cooling water circuit 21 heat exchangers 22 Bypass 23 Control valve 24 actuator 25 Internal combustion engine 26 Low-temperature charge air coolers 27 High-temperature charge air coolers 28 Cooling water pump 28a Coolant pump 28b Cooling water pump 29 Actuator 29a Actuator 29a Actuator 30 Control valve 31 Actuator 32 coolers 33 Cooling water pump 34 Bypass 35 Management 36 Cooling water pump 37 Control valve 38 Actuator 39 Actuator 40 actuator 41 regulators 42 Assembly 43 Sensor

Claims

Method for operating a cooling system (10) of a ship, wherein the cooling system (10) comprises a seawater subsystem (11) with a seawater pump (14a, 14b) and at least one first cooling water circuit (13); the seawater subsystem (11) and the first cooling water circuit (13) are coupled via a heat exchanger (12) such that, in the region of the heat exchanger (12), the cooling water of the first cooling water circuit (13) is cooled by the seawater of the seawater subsystem (11); the first cooling water circuit (13) has a bypass (17) to the heat exchanger (12) coupling the seawater subsystem (11) and the first cooling water circuit (13) and a control valve (18) whose position determines which portion of the cooling water of the first cooling water circuit (13) is routed through the heat exchanger (12) and which portion of the cooling water of the first cooling water circuit (13) is routed through the bypass (17). is, whereby the position of the control valve (18) is regulated in such a way thatthat a supply cooling water temperature, which is set by mixing the cooling water portion routed via the heat exchanger (12) and the cooling water portion routed via the bypass (17), corresponds to a corresponding setpoint; characterized in that the speed of the seawater pump (14a, 14b) of the seawater subsystem (11) is controlled depending on the position of the control valve (18) of the first cooling water circuit (13), the position of which determines which cooling water portion of the first cooling water circuit (13) is routed via the heat exchanger (12) and which cooling water portion of the first cooling water circuit (13) is routed via the bypass (17), wherein the first cooling water circuit (13) comprises a cooling water pump (28a, 28b), a low-temperature charge air cooler (26), at least one cooler (32) for cooling at least one further assembly, and a further control valve (30),via whose switching position a cooling water portion of the first cooling water circuit (13) routed via the low-temperature charge air cooler (26) can be adjusted, a speed of the cooling water pump (28a, 28b) of the first cooling water circuit (13) is regulated depending on the position of the control valve(s) (18, 30) of the first cooling water circuit (13). Method according to claim 1, characterized in that the rotational speed of the seawater pump (14, 14b) is controlled, in particular reduced, as a function of the position of the control valve (18) of the first cooling water circuit (13) in such a way that the proportion of cooling water of the first cooling water circuit (13) passing through the heat exchanger (12) is as large as possible and is thus brought closer to a corresponding setpoint. Method according to claim 1 or 2, characterized in that the speed of the seawater pump (14a, 14b) is further controlled depending on the temperature of the seawater downstream of the heat exchanger (12). Method according to claim 3, characterized in that when the temperature of the seawater downstream of the heat exchanger (12) becomes greater than a limit value, the rotational speed of the seawater pump (14a, 14b) is increased so that the temperature of the seawater becomes less than or equal to the limit value. Method according to one of claims 1 to 4, characterized in that the cooling system comprises a second cooling water circuit (20); the second cooling water circuit (20) and the seawater subsystem (11) or the second cooling water circuit (20) and the first cooling water circuit (13) are coupled via a heat exchanger (21), in the region of which the cooling water of the second cooling water circuit (20) is cooled by the seawater or the cooling water of the first cooling water circuit (13);The second cooling water circuit (20) has a bypass (22) to the heat exchanger (21) coupling the second cooling water circuit (20) and the seawater subsystem (11) or the second cooling water circuit (20) and the first cooling water circuit (13), and a control valve (23) whose position determines what proportion of the cooling water of the second cooling water circuit (20) is routed through the heat exchanger (21) and what proportion of the cooling water of the second cooling water circuit (20) is routed through the bypass (22), wherein the position of the control valve (23) of the second cooling water circuit is regulated such that a return cooling water temperature upstream of the heat exchanger (21) of the second cooling water circuit (20) corresponds to a corresponding setpoint; the speed of the seawater pump (14a, 14b) of the seawater subsystem (11) is further regulated depending on the position of the control valve (23) of the second cooling water circuit (20). Method according to claim 5, characterized in that the rotational speed of the seawater pump (14a, 14b) is controlled, in particular reduced, such that, on the one hand, the cooling water fraction of the first cooling water circuit (13) passing through the heat exchanger (12) of the first cooling water circuit (13) is maximized and thus approximated towards a corresponding setpoint, and that, on the other hand, the cooling water fraction of the second cooling water circuit (20) passing through the heat exchanger (21) of the second cooling water circuit (20) is maximized and thus approximated towards a corresponding setpoint. Method according to one of claims 1 to 6, characterized in that the speed of the cooling water pump (28a, 28b) of the first cooling water circuit (13) is regulated as a function of the position of the control valves (18, 30) of the first cooling water circuit (13) such that the proportion of cooling water of the first cooling water circuit (13) that passes through the low-temperature charge air cooler (26) is as large as possible and is thus brought closer to a corresponding target value. Method according to claim 1 or 7, characterized in that the speed of the cooling water pump (28a, 28b) of the first cooling water circuit (13) is further controlled depending on the temperature of at least one cooler (32) for cooling at least one further assembly. Method according to one of claims 5 or 6 and one of claims 1, 7 or 8, characterized in that the second cooling water circuit (20) and the first cooling water circuit (13) are coupled via the heat exchanger (21) of the second cooling water circuit (20), and the speed of the cooling water pump (28a, 28b) of the first cooling water circuit (13) is additionally controlled depending on the position of the control valve (23) of the second cooling water circuit (20). Method according to one of claims 5 to 9, characterized in that the second cooling water circuit (20) comprises a high-temperature charge air cooler (27) and a cooling water pump (33), wherein the speed of the cooling water pump (33) of the second cooling water circuit (20) is controlled depending on the internal combustion engine. A method according to one of claims 1 to 4, characterized in that the first cooling water circuit (13) comprises a cooling water pump (28a, 28b), a low-temperature charge air cooler (26), a high-temperature charge air cooler (27), at least one cooler (32) for cooling at least one further assembly, and a further control valve (30), as well as a further control valve (37), the switching position of which allows adjustment of the cooling water portion routed through the low-temperature charge air cooler (26) and the cooling water portion routed through the high-temperature charge air cooler (27); the speed of the cooling water pump (28a, 28b) of the first cooling water circuit (13) is controlled depending on the position of one or each control valve (18, 30, 37) of the first cooling water circuit (13). Method according to claim 11, characterized in that the speed of the cooling water pump (28a, 28b) of the first cooling water circuit (13) is controlled, in particular reduced, in such a way that the proportion of cooling water passed through the high temperature charge air cooler (27) is as large as possible and is thus brought closer to a corresponding target value.

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