DK178889B1

DK178889B1 - METHOD AND FUEL MANAGEMENT SYSTEM FOR A MARINE SHIP

Info

Publication number: DK178889B1
Application number: DKPA201500364A
Authority: DK
Inventors: Klaus Bruun Egeberg
Original assignee: A P Møller - Mærsk As
Priority date: 2015-06-25
Filing date: 2015-06-25
Publication date: 2017-05-01
Also published as: DK201500364A1; WO2016206694A1

Abstract

A method for controlling fuel consumption of a marine vessel (1) with at a storage tank (10) and a day tank (25), a plurality of fuel consuming devices(4,14), including a main large two-stroke turbocharged diesel engine (4) and an auxiliary four-stroke diesel engine (14), the method comprising: batch wise filling the day tank (25) from the storage tank (10) with fuel, metering the amount of fuel transferred from the storage tank (10) to the day tank (25) with a first flowmeter (23) and recording the amount measured by the first flowmeter (23) with an electronic controller (50), metering the amount of fuel transferred from the day tank (25) to the plurality of fuel consuming devices (4,14,19) with a second flowmeter (26,126) and recording the amount measured by the second flowmeter with the electronic controller (50), determining a first sum of the recorded amount of fuel transferred from the storage tank (10) to the day tank (25) over time with the electronic controller (50) determining a second sum of the recorded amount of fuel transferred from the day tank (10) to the fuel consuming devices (4,14,19) over the same time with the electronic controller (50) determining with the electronic controller (50) a difference between the first sum and the second sum, and determining with the electronic controller (50) if the determined difference between the first sum and the second sum exceeds a threshold.

Description

FUEL MANAGEMENT METHOD AND SYSTEM FOR MARINE VESSEL TEHCNICAL FIELD

The present invention relates to a fuel system and method for controlling fuel consumption of a marine vessel, in particular controlling the flow of fuel on a marine vessel from a storage tank to the fuel consuming device, such as e.g. the main engine.

BACKGROUND

Marine vessels are large ocean going ships that are used for transporting passengers or for transporting various kinds of goods. Typically, such a marine vessel provided with one or more main engines each coupled to a propeller for propulsion and one or more auxiliary engines coupled to a generator for generating electrical power. These engines consume significant amounts of fuel. Most Marine vessels are also provided with a boiler that uses the same type of fuel as the engines. Thus, the Marine vessel uses a significant amount of fuel. Conventionally, the amount of fuel used/transferred to the measured was measured by simple metering equipment, like dip sticks and was manually recorded. Control over the transfer of fuel aboard marine vessel 1 was not accurate and complete .

Recently, meters of being developed for metering the amount of fuel that is taken on board into a storage tank during bunkering. Similar meters also been recently developed to measure the amount of fuel delivered to the engines and the boiler. Typically, these meters are vibrating flowmeters based on the Coriolis effect, i.e. these are electronic flowmeters that allow automatic recording of the amount of fuel transferred. DK 201300607 discloses a method according to the preamble of claim 1 and a marine vessel according to the preamble of claim 6.

SUMMARY

On this background it is an object to overcome or at least reduce the drawbacks indicated above.

The object above is achieved in accordance with a first aspect by providing a method for controlling fuel consumption of a marine vessel, the marine vessel comprising at least one storage tank for storing fuel and at least one day tank, a plurality of fuel consuming devices, the plurality of fuel consuming devices including at least one main large two-stroke turbocharged pressure ignited combustion engine for providing propulsion for the marine vessel and at least one auxiliary four-stroke pressure ignited combustion engine for generating electrical power for the marine vessel and optionally a boiler for generating steam, the method comprising: batch wise filling the day tank from the storage tank with fuel, metering the amount of fuel transferred from the storage tank to the day tank with a first flowmeter and recording the amount measured by the first flowmeter with an electronic controller, metering the amount of fuel transferred from the day tank to the plurality of fuel consuming devices with a second flowmeter and recording the amount measured by the second flowmeter with the electronic controller, determining a first sum of the recorded amount of fuel transferred from the storage tank to the day tank over time with the electronic controller from the readings of the first meter, determining a second sum of the recorded amount of fuel transferred over the same time from the day tank to the fuel consuming devices with the electronic controller from the readings of the second meter, and determining with the electronic controller a difference between the first sum and the second sum.

By recording the sum of fuel transferred from the storage tank to the data and by comparing the sum with the sum of fuel transferred from the day tank to the engine it becomes possible to determine to check the mass balance and verify that the fuel in the storage tank indeed ends up being consumed by one of the fuel consuming devices. A small portion of the fuel, which is typically heavy fuel, is sludge that is removed from the fuel system and cannot be used in the fuel consuming devices. The percentage of the fuel that ends up as sludge should not exceed a given percentage of the total amount of fuel. If the difference between the record sums is over a certain threshold this is an indication the funeral is wasted or misused. By comparing the two sums, it becomes possible to determine a mass balance, to determine how the fuels consumed with a documented audit trail of how much fuel is consumed and hereby be able to document how the fuel is being spent (divided by machinery type (Main Engine, Auxiliary and boiler)), mitigating fraud/short deliveries and how much is being excess in terms of sludge (waste).

Using the data collected from both the bunker intake system and the bunker consumption system, it is possible to make a mass balance, with a documented audit trail of how much bunker is ordered, how much received, how it is consumed and thereby render it possible to document how the bunker is being spent (divided by machinery type (Main Engine, Auxiliary and boiler)), mitigating fraud/short deliveries and how much is excess in terms of sludge (waste).

According to a first possible implementation of the first aspect the method further comprises the controller being configured to determining if the determined difference between the first sum and the second sum exceeds a threshold, and the controlled preferably being configured to issue a notification when the determined difference exceeds the threshold.

According to a second possible implementation of the first aspect the method further comprises determining the threshold as a percentage of the first sum.

According to a third possible implementation of the first aspect the second flowmeter comprises several flowmeters that preferably measure the amount of fuel transferred to the individual fuel consuming devices.

According to a fourth possible implementation of the first aspect the first flowmeter and/or the second flowmeter is a vibrating flow meter, preferably a Coriolis flowmeter.

According to a fifth implementation of the first aspect the method further comprises metering the amount of fuel transferred to the storage tank during a bunkering operation with a third flow meter and recording the transferred amount during bunkering in the electronic control unit.

According to a sixth implementation of the first aspect the method further comprises comparing the recorded amount transferred during bunkering with said first sum.

According to a seventh implementation of the first aspect the method further comprises recording a complete full mass balance from bunkering to consumption by the fuel consuming devices.

The object above is also achieved in accordance with a second aspect by providing a marine vessel comprising: at least one storage tank for storing fuel, at least one day tank, the day tank being connected to the storage tank for batch wise filling the day tank from the storage tank, a first flowmeter in the connection between the storage tank and the day tank a plurality of fuel consuming devices connected to the day tank for being supplied with fuel from the day tank, the plurality of fuel consuming devices including at least one main large two-stroke turbocharged pressure ignited combustion engine coupled to a propeller for propulsion of the marine vessel and at least one auxiliary four-stroke pressure ignited combustion engine for generating electrical power for the marine vessel and optionally a boiler for generating steam, a second flowmeter between the day tank and the plurality of fuel consuming devices, an electronic controller, the electronic controller being in receipt of a signal from the first flowmeter, the electronic controller being in receipt of a signal from the second flowmeter, the electronic controller being configured for recording the amount measured by the first flowmeter, the controller being configured for recording the amount measured by the second flowmeter, the electronic controller being configured for: determining a first sum of the recorded amount of fuel transferred from the storage tank to the day tank over time, determining a second sum of the recorded amount of fuel transferred from the day tank to the fuel consuming devices over the same time, and determining a difference between the first sum and the second sum.

According to a first possible implementation of the second aspect the controller is configured to determine if the determined difference between the first sum and the second sum exceeds a threshold, and the controller is preferably also configured to issue an alarm or notification when the difference exceeds the threshold.

According to a second possible implementation of the second aspect the controller is configured to reset the first sum and the second sum to zero after the threshold has been exceeded.

According to a third possible implementation of the second aspect the controller is configured to determine the difference by subtracting the second sum from the first sum.

According to a fourth possible implementation of the second aspect the controller is configured to calculate the difference as a percentage of the first sum.

According to a fifth possible implementation of the second aspect the controller is configured to control the operation of a transfer pump in the connection between the storage tank and the day tank.

According to a sixth possible implementation of the second aspect the first flowmeter is a vibrating mass flowmeter, preferably a Coriolis flowmeter.

According to a seventh possible implementation of the second aspect the second flowmeter is a vibrating mass flowmeter, preferably a Coriolis flowmeter.

According to an eighth possible implementation of the second aspect the second flowmeter is formed by several individual flowmeters that are placed in the connection between the day tank and the individual fuel consuming devices .

According to a ninth possible implementation of the second aspect a settling tank is provided between the storage tank and the day tank.

According to a tenth possible implementation of the second aspect the volume of the day tank is significantly less than the volume of the storage tank.

According to an eleventh possible implementation of the second aspect the marine vessel is provided with a third flowmeter in the connection between a bunkering manifold and the storage tank for measuring the amount of fuel transferred during a bunkering operation.

These and other aspects of the invention will be apparent from and the example embodiments described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present description, the invention will be explained in more detail with reference to the exemplary embodiments shown in the drawings, in which:

Fig. 1 is a side view of a marine vessel according to an example embodiment,

Fig. 2 is a rear view of the marine vessel of Fig. 1 and of a bunkering barge during a bunkering operation,

Fig. 3 is a diagrammatic representation of a fuel system of the marine vessel of Fig. 1,

Fig. 4 is a more detailed illustration of the fuel system according to Fig. 3,

Fig. 5 is a graph illustrating fuel transfers on a marine vessel over time,

Fig. 5 is a graph illustrating fuel transfers on another marine vessel over time, and

Fig. 6 is a flow chart of a method for controlling fuel consumption of a marine vessel according to an embodiment.

DETAILED DESCRIPTION

Fig. 1 shows a marine vessel in the form of large ocean going cargo ship 1 according to an example embodiment in side view. In this embodiment the marine vessel is a container ship. However, the marine vessel 1 could just as well be a general cargo vessel, a tanker, a dry-bulk carrier, a multipurpose vessel, a reefer ship, a passenger ship or any other large ocean going type of marine vessel that uses liquid fuel, such as e.g. fuel oil or heavy fuel oil.

Marine vessel 1 has a hull 2 and one or more engine rooms 3 provided inside the hull 2. The marine vessel 1 is powered by one or more large self-igniting internal combustion engines 4, i.e. four-stroke or two-stroke self-igniting combustion engines 4 located in an engine room 3. The large self-igniting internal combustion engine (s) 4 drive (s) the propellers (s) 12 and there may be one or more auxiliary engines (generator sets) 14 (Fig. 3) that provide electrical power and heat for various consumers aboard the marine vessel 1.

At least one fuel storage tank 10 (bunker) is provided in the hull 2 in a suitable location. Typically, there will be several interconnected fuel storage tanks 10. If the marine vessel 1 is operated with heavy fuel oil the storage tank or tanks 10 for heavy fuel oil will be heated at all times to ensure that the heavy fuel oil remains flowable. Also the further components of the fuel system further downstream of the storage tank will be provided with means such as steam tracing to ensure that the heavy fuel oil will remain flowable throughout the fuel system.

The marine vessel 1 also has one or more funnels 6 and a bridge 7. Containers are shown on the deck in container bays filled with rows of containers in a plurality of tiers. Containers can also be stowed inside cargo space in the hull 2.

Fig. 2 is a diagrammatic rear view of the marine vessel 1 when it is moored and a bunkering barge 5 alongside and with the starboard bunkering manifold 9 connected to the bunkering barge 5 via a hose that is supported by a crane of the bunkering barge 5. The marine vessel 1 could also receive bunker fuel from tanks or other storage facilities on shore using the port bunkering manifold 9. At the start of a bunkering operation the bunkering barge 5 is moored and alongside the marine vessel 1 and the free end of hose is connected to one of the two bunkering manifolds 9. During bunkering fuel is pumped from a bunker fuel tank 40 in the bunkering barge 5 via the pipe or hose to one of the bunker manifolds 9 and from there it flows into the storage tank 10 in the marine vessel 1.

Fig. 3 is a diagrammatic representation of a fuel system according to an example embodiment and also showing several fuel consuming devices 4,14,19. In this example embodiment the fuel consuming devices include a main large two-stroke turbocharged compression ignited internal combustion engine 4, two auxiliary four-stroke compression ignited internal combustion engines and a boiler 19.

The fuel system includes a storage tank 10. The storage tank 10 is provided with a bunker line 8 connected to each of the bunker manifolds 9.

Through bunker line 8 and its manifold, fuel oil is supplied from e.g. a bunkering barge 5. Although only one storage tank 10 is shown in the figures it is understood that there can be several connected storage tanks 10 in the marine vessel 1. A transfer pump 13 in a feed conduit pumps fuel oil from the bunker tank 10 via the feed conduit to a day tank 25. A filter may be used in the feed conduit to prevent large impurities from being transported to the day tank 25. A first flow meter flowmeter 23 in the feed conduit between the storage tank 10 and the day tank 25 measures the amount of fuel transferred from the storage tank 10 to the day tank 25. The first flow meter 23 is in an embodiment a vibrating flow meter of e.g. the Coriolis type and measures the mass of the fuel flowing through the meter. An electronic control unit 50 is in receipt of a signal from the first flow meter 23. The electronic control unit 50 is configured to record the amount (mass) of the fuel transferred to the day tank 10. A fuel line connects each of the fuel consuming devices 4,14,19 with the day tank 25. The fuel line branches off to each of the fuel consuming devices 4,14,19. A flow meter 26, 126 is provided in each of the branches of the fuel line in order to meter the amount of fuel consumed by the respective fuel consuming devices 4,14,19. Thus, a second flow meter 26 is provided in the branch of the fuel line that connects to the main engine 4. This branch also includes a feed pump 28. The second flow meter 26 is in an embodiment a vibrating flow meter of e.g. the Coriolis type and measures the mass of the fuel flowing through the meter. The electronic control unit 50 is in receipt of a signal from the second flow meter 26. The electronic control unit 50 is configured to record the amount (mass) of the fuel transferred to the main engine 4 .

Similarly, each of the other fuel consuming devices 4,14,19, such as the two auxiliary engines 14 and the boiler 19 are each provided with fuel from the day tank 25 via their individual branch of the fuel line that includes a second flowmeter 126 and a feed pump 128. Each of the second flowmeters 26,126 meters the amount (mass) of fuel flowing through the respective branch and each of the second flow meters 26, 126 is connected to the electronic control unit 50.

The electronic control unit 50 is configured record the amount of fuel transfer to each of the fuel consuming devices 4, 14, 19. In an embodiment the feed pumps 28,128 are also connected to the electronic control unit 50.

In an embodiment (not shown) the a second flow meter 26 is placed upstream of the position where the fuel line branches and thus a single second flow meter 26 meters the whole amount of fuel transferred from the day tank 10 to all of the fuel consuming devices 4,14,19.

Filling of the day tank 25 from the storage tank 10 is typically performed batch wise, whilst the consumption of fuel by the fuel consuming devices is typically in a more steady fashion, at a higher level when marine vessel 1 is sailing and uses all the fuel consuming devices including the main engine 4 and at a lower level when the marine vessel is in port and the main engine 4 is stopped but with typically at least one of the auxiliary engines running.

The electronic control unit 50 is configured to record the amount of fuel transferred to the fuel consuming devices 4,14,19 over time. The electronic control unit 50 is also configured to record the amount of fuel transferred from the storage tank 10 to the day tank 10 over the same time.

The electronic control unit 50 is configured to sum the amount of fuel transferred over time from the storage tank 10 to the day tank 25 in a first sum and to sum the amount of fuel transferred over the same time to the fuel consuming devices 4,14,19 in a second sum.

Fig. 5 is a graph that illustrates the development over time of the first sum as a grey area and the second sum as a dark line. The batch wise filling of the day tank 10 can be recognized by the steps in the gray area. The graph shows an example of the development of each of the sums from May 5, 2015 to June 8, 2015 of a first marine vessel and represents a mass balance in the fuel system. The mass balance at the end of the measuring period was -31.4 metric tons, corresponding to -1.1% of the supplied fuel. Depending on the quality of the fuel, a loss of 1.1% is expected.

Fig. 6 shows the same graph for the development of a second marine vessel. The mass balance at the end of the measuring period was -68.8 metric tons, corresponding to -2.4% of the supplied fuel. Depending on the quality of the fuel, a loss of 2.4% is more than expected and the name of the quality of the fuel the process it could be configured to issue a notification or alarm when loss reaches 2.4%.

The comparing of the sums is done after a certain amount of time in order to make sure that any fluctuations due to the stepwise filling of the day of become negligible. Alternatively, the controller 50 can be provided with an algorithm to compensate for the effect on the first sum of the batch wise filling process of the day tank 25.

At the start of measurements the first sum and the second sum are recorded and taken into account or they are reset by the electronic control unit 50 to zero or to an equal value of choice (in Fig. 5 to zero) . The reset procedure can be automatic (initiated by the electronic control unit 50) or initiated by a human operator and carried out by the electronic control unit.

The electronic control unit 50 is in an embodiment configured to determine a difference between the first sum and the second sum.

The electronic control unit 50 is configured to issue a notification or alarm when the difference exceeds a threshold.

In an embodiment, the electronic control unit 50 is configured to subtract the second sum from the first sum in order to determine the difference between the two sums. The electronic control unit 50 can further be configured to determine the size of the difference relative to the size of the first or second sum or the average of the first and second sum. Thus, the threshold for the electronic control unit 50 issuing and alarm can be set at a percentage of the e.g. the first sum. An excess amount of fuel being removed as sludge and thereby creating a difference between the sums that exceeds the threshold can be an indication of the fuel quality that is less than expected (ordered) or point to the irregularities .

The notification issued by the electronic control unit 50 can be in the form of a message that is transmitted to a remote recipient and/or in the form of a message is transmitted to a local recipient on board of the marine vessel 1.

Fig. 4 is a more detailed diagrammatic illustration of the fuel system and one of the fuel consuming devices (main engine 4).

The storage tank 10 is connected to the bunker manifolds 9 via the bunker line 8 that includes a third flow meter 20. In an embodiment the third flow meter 20 is a vibrating meter of the Coriolis type that measures the mass of the fuel flowing through the third flow meter 20. The third flow meter 20 is connected to the electronic control unit 50 for recording the amount of fuel transferred to the storage tank 10 during bunkering. Thus, the electronic control unit 50 can also verify the fuel mass balance in relation to the amount of fuel bunkered, by comparing the first sum with the amount of fuel taken in during bunkering.

Based on the numbers on the amount of fuel that it is taken in during bunkering and on the amount of fuel used by consumption, the electronic control unit 50 or another local or remotely located electronic control unit calculates stock numbers, based on these parameters.

In an embodiment the electronic control unit is 50 is configured to determine the amount of fuel in the storage tank by comparing the amount of fuel bunkered with the first sum, preferably taking into account an initial amount of fuel in the storage tank 10 before the last bunkering operation.

In an embodiment the electronic control unit 50 or another local or remote but connected electronic control unit is configured to determine the stock levels of fuel on board the marine vessel 1 and configured to determine precisely the amount of fuel needed to bunker for a given upcoming voyage . A pipe 57 connects a fuel outlet of the storage tank 10 to the inlet of a settling tank 15. The settling tank allows the fuel oil to settle for removal of particulates that accumulate at the bottom of the settling tank 15 from where sludge with the particulate is drained and removed from the fuel. The outlet of the settling tank 15 is connected to the inlet of a heater 18 via conduit 57 and transported by a transfer pump 11.

The operation of the transfer pumps 11,13 and the heater 18 is in an embodiment controlled by the electronic control unit 50 (Fig. 3).

The fuel inlet of the day tank 25 is connected to the outlet of the heater 18 via pipe 57. A fuel outlet of the day tank 25 connects to a fuel oil mixing tank 30 via piping 61. In the connection between the fuel oil day tank 25 and the fuel oil mixing tank 30 there is provided the second flow meter 26, a fine filter 27 (e.g. a 10-34 micron filter) and a feed pump 28. The electronic control unit 50 (Fig. 3) controls the speed of the feed pump 28 and receives a signal representative of the mass flow through the flow meter 26. The fine filter 27 prevents impurities to reach the mixing tank 30. A fuel outlet of the mixing tank 30 connects to the inlet of the fuel injection system of the main engine 4 by a fuel line 31. This connection includes a booster pump 33 followed by a fuel heater 34. A fuel return pipe 32 connects the fuel injection system of the main engine 4 to a fuel return port of the mixing tank 30. The measured viscosity of the crude oil is in an embodiment measured using standardized equipment such as e.g. viscosirator 38 or the like. In an embodiment the signal reflecting the measured viscosity of the fuel oil is send to the electronic control unit 50. The measured viscosity is then used by the electronic control unit 50 to regulate the heater 34 and thereby the viscosity of the fuel oil flowing to the fuel injection system. A bypass line with a pressure regulation valve 37 allows fuel to be recirculated back into the mixing tank 30 and thereby to regulate the pressure in fuel line 31.

The first flowmeter 23, the second flowmeter 26 and the third flowmeter 20 are in an embodiment vibrating flowmeters of the Coriolis type that measure the mass of the fuel flowing through the flow meter.

Fig. 7 is a flow chart illustrating an example embodiment of a method for controlling fuel consumption of a marine vessel 1.

At the start of the method the first sum and the second sum are set to initial value that can be zero or another equal amount in step 101. Next, a batch of fuel is transferred from fuel storage tank 10 to the day tank 25. The transferred amount is measured by the first flowmeter 23 and the amounts (mass) transferred over time are recorded and added to the first sum by the electronic control unit 50 in step 102.

The amount (mass) of fuel that is consumed by the fuel consumers 4, 14, 19 is metered from the start by the second flow meter 26 and the amount consumed over time is recorded and added to the second sum by the electronic control unit 50 in step 103.

The difference between the first sum and the second sum is monitored by the electronic control unit 50 in step 104 (typically, the second sum will be slightly smaller than the first sum due to losses in the form of sludge that is removed from the fuel before it is transferred to the fuel consuming devices).

In step 105 the electronic control unit 50 determines whether the difference between the first sum the second sum is larger than a given threshold, e.g. larger than 1% of the first sum.

If the difference is larger than the given threshold the electronic control 50 moves on to step 106 and issues a notification or alarm. Thereafter, the process moves back to step 101 where the first and second sums are reset.

If the electronic control unit 50 determines in step 105 that the difference does not exceed the given threshold the process moves to step 102 in the process in steps 102 to 105 of monitoring and summing the fuel consumption and detecting any mismatch in the fuel mass balance is repeated.

The invention has been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. The reference signs used in the claims shall not be construed as limiting the scope .

Claims

METHOD AND FUEL MANAGEMENT SYSTEM FOR A MARINE SHIP

1. A method of controlling fuel consumption for an ocean-going ship (1), comprising at least one fuel storage tank (10) and at least one day tank (25), a plurality of fuel-consuming devices (4, 14), which plurality of fuel-consuming devices (4, 14, 19) include at least one large two-stroke, turbocharged, main-ignition main combustion engine (4) to provide propulsion for the seagoing ship (1) and at least one four-stroke, high-pressure secondary combustion engine (14) for generating electric current to the seagoing ship (1) and optionally a steam generating boiler (19), comprising: batch-filling the daily tank (25) from the storage tank (10) with fuel, measuring the amount of fuel transferred from the day tank (25) for the plurality of fuel-consuming devices (4, 14, 19), with a second flow meter (26, 126) and recording the amount measured by the second flow meter with d. an electronic control unit (50), characterized by: measuring the amount of fuel transferred from the storage tank (10) to the day tank (25), with a first flow meter (23) and recording the amount measured by the first flow meter (23), with an electronic control unit (50), determining an initial sum of the recorded amount of fuel transferred from the storage tank (10) to the day tank (25) over time, with the electronic control unit (50) from the readings of the first flow meter (23), determining a second sum of the recorded amount of fuel transferred from the day tank (10) to the fuel-consuming devices (4, 14, 19) over the same time, with the electronic control unit (50) from the readings of the second flow meter (26), and determining with the electronic control unit (50) a difference between the first sum and the second sum.

The method of claim 1, further comprising determining with the electronic control unit (50) if the determined difference between the first sum and the second sum exceeds a threshold value, and further preferably comprises the sending of a notification when the particular difference exceeds the threshold.

The method of claim 1 or 2, further comprising determining the threshold value as a percentage of the first sum.

4. A method according to any one of claims 1 to 3, wherein the second flow meter comprises several flow meters (26, 126), which preferably measure the amount of fuel transferred to the individual fuel-consuming devices (4, 14, 19).

5. The method of any one of claims 1 to 4, wherein the first flow meter (23) and / or the second flow meter (26, 126) is a vibrating flow meter, preferably a Coriolis flow meter.

A seagoing vessel comprising: at least one fuel storage tank (10), at least one fuel tank (25), which fuel tank (25) is connected to the storage tank (10) for batch filling of the fuel tank (25) from the storage tank (10) ), a plurality of fuel-consuming devices (4, 14, 19) connected to the fuel tank (25) for supplying fuel from the fuel tank (25), the plurality of fuel-consuming devices (4, 14, 19) including at least one large two-stroke turbocharger , pressurized main combustion engine (4) coupled to a screw (12) for propulsion of the seagoing ship (1) and at least one four-stroke pressurized auxiliary combustion engine (14) for generating electric current for the seagoing ship (l) and optionally a steam generating boiler (19), another flow meter (26) between the day tank (25) and the plurality of fuel-consuming devices (4, 14, 19), an electronic control unit (50), which electronic control unit (50) can receive a signal from the second flow meter (26), characterized by: a first flow meter (23) in the connection between the storage tank (10) and the day tank (25), which electronic control unit (50) can receive a signal from the first flow meter (23), which electronic control unit (50) is configured to record the amount measured by the first flow meter (23), which control unit (50) is configured to record the amount measured by the second flow meter (26), which electronic control unit (50) is configured for: determining a first sum of the recorded amount of fuel transferred from the storage tank (10) to the day tank (25) over time, determining a second sum of the recorded amount of fuel transferred from the day tank (25 ) for the fuel-consuming devices over the same time, and determining a difference between the first sum and the second sum.

A seagoing ship (1) according to claim 6, wherein the controller (50) is configured to determine whether the particular difference between the first sum and the second sum exceeds a threshold value, and wherein the controller is preferably configured to emit an alarm or notification when the difference exceeds the threshold.

A seagoing ship (1) according to claim 6 or 7, wherein the controller (50) is configured to reset the first sum and the second sum after the threshold has been exceeded.

A seagoing ship (1) according to any one of claims 6 to 8, wherein the controller (50) is configured to determine the difference by subtracting the second sum from the first sum.

A seagoing ship (1) according to claim 9, wherein the control unit (50) is configured to calculate the difference as a percentage of the first sum.

A seagoing ship (1) according to any one of claims 6 to 10, wherein the control unit (50) is configured to control the operation of a transfer pump (13) in the connection between the storage tank (10) and the day tank (25).

A seagoing ship (1) according to any one of claims 6 to 11, wherein the first flow meter (23) is a vibrating flow meter, preferably a Coriolis flow meter.

A seagoing ship (1) according to any one of claims 6 to 12, wherein the second flow meter (26) is a vibrating flow meter, preferably a Coriolis flow meter.

A seagoing ship (1) according to any one of claims 6 to 13, wherein the second flow meter (26, 126) is formed by several individual flow meters (26, 126) located in the connection between the day tank (25) and the individual fuel-consuming devices (4, 14, 19).

A seagoing ship (1) according to any one of claims 6 to 14, wherein a settling tank (15) is provided between the storage tank (10) and the day tank (25).