Ship automatic pressurized and unloading control method and ship automatic pressurized and unloading device

Abstract

The application relates to a ship automatic ballast control method and a ship automatic ballast device. The control method comprises the following steps: acquiring real-time ship four-corner water level data; calculating ship stability parameters based on the data; determining to execute a ballast operation or a ballast discharge operation according to the stability parameters, and selecting a main ballast pump group or an auxiliary ballast pump; determining a target ballast tank and controlling an isolation valve to be opened; and controlling the selected pump group to execute the ballast operation or the ballast discharge operation. By acquiring the ship four-corner water level data, calculating the ship stability parameters, selecting the main ballast pump group or the auxiliary ballast pump, determining the target ballast tank to open the corresponding isolation valve, executing the ballast operation or the ballast discharge operation, and until the ship restores the stability state, the ballast operation or the ballast discharge operation is automatically completed according to the actual operation condition of the ship, the stability of the ship is effectively improved, and the safety and reliability of the ship are improved.

Description

Technical Field

[0001] This application relates to the field of marine engineering vessel technology, and in particular to automatic ballast control methods and automatic ballast devices for ships. Background Technology

[0002] With the development of ship automation control technology, automatic ballast water control technology based on sea state monitoring has emerged. This technology uses marine environmental parameters such as wind direction, wind speed, and wave amplitude as input sources to construct an automatic ballast water adjustment algorithm.

[0003] In related technologies, environmental sensor networks are typically used to monitor external sea conditions in real time. After the collected data is input into the control system, the liquid level adjustment scheme of each ballast tank is calculated through a preset algorithm model, and the ballast pumps and valves are automatically started and closed to perform adjustment operations.

[0004] However, the aforementioned automatic control methods have significant drawbacks: First, their control logic relies excessively on external sea state parameters and fails to effectively identify the dynamically changing loading conditions during actual ship operations, particularly the complex operational scenarios frequently encountered by marine engineering vessels, such as oil and gas storage and transportation, material replenishment, and waste disposal. Second, existing systems construct control models based on numerous superficial parameters but fail to grasp the essential parameters of ship stability regulation—the deviation between the ship's actual and theoretical center of gravity, the rate of change of the ship's draft, and the liquid level in the compartments. This control strategy results in a lag in system response, making it difficult to achieve precise and rapid stability regulation when facing the variable operating conditions of floating platforms such as FLNG and FPSO. Manual intervention for parameter correction is still required, weakening the practical application value of automated control.

[0005] In summary, the above-mentioned ballast adjustment methods have problems such as complex data processing, slow response, and insufficient accuracy. Summary of the Invention

[0006] Therefore, it is necessary to provide an automatic ballast removal control method and device for ships, addressing the problems of complex data processing, slow response, and insufficient accuracy in existing ship ballast adjustment technologies.

[0007] An automatic ballast removal control method for ships includes:

[0008] Real-time acquisition of draft and liquid level data at the four corners of the ship;

[0009] Calculate the ship's stability parameters based on the data;

[0010] The ballast or de-ballast operation is determined based on the stability parameters, and the main ballast / de-ballast pump set or auxiliary ballast / de-ballast pump is selected.

[0011] Identify the target ballast tank and control the opening of the corresponding isolation valve;

[0012] Control the selected pump set to perform ballast or discharge operations.

[0013] In one embodiment, the stability parameter is the difference between the actual center of gravity and the theoretical center of gravity, and determining whether to perform ballast or unloading operations includes:

[0014] When the difference between the actual center of gravity and the theoretical center of gravity is positive, ballast operation is performed;

[0015] When the difference between the actual center of gravity and the theoretical center of gravity is negative, a load scheduling operation is performed.

[0016] In one embodiment, determining to perform a ballast or unloading operation includes:

[0017] When the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to the first center of gravity threshold, ballast or unloading operations are performed.

[0018] If the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is less than the first center of gravity threshold, then no ballast or unloading operation will be performed.

[0019] The first centroid threshold is 300mm.

[0020] In one embodiment, selecting the main pressure discharge pump group or the auxiliary pressure discharge pump includes:

[0021] If the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to the second center of gravity threshold, the main pressure discharge pump group will be started.

[0022] If the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to the first center of gravity threshold and less than the second center of gravity threshold, the auxiliary pressure discharge pump will be started.

[0023] When the main ballast pump group or auxiliary ballast pump is started, if the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is less than the third center of gravity threshold, the main ballast pump group or auxiliary ballast pump is stopped.

[0024] The second centroid threshold is 500mm, and the third centroid threshold is 10mm.

[0025] In one embodiment, the stability parameter is the actual rate of change of liquid level, and determining whether to perform ballast or de-ballast operation includes:

[0026] When the actual rate of change of liquid level is negative, ballast operation is performed.

[0027] When the actual rate of change of liquid level is positive, the discharge operation is executed.

[0028] In one embodiment, determining to perform a ballast or unloading operation includes:

[0029] When the absolute value of the actual liquid level change rate is greater than or equal to the first liquid level change threshold, perform ballast or discharge operation.

[0030] If the absolute value of the actual liquid level change rate is less than the first liquid level change threshold, then ballast or discharge operations will not be performed.

[0031] The first liquid level change threshold is 20 mm / h.

[0032] In one embodiment, selecting the main pressure discharge pump group or the auxiliary pressure discharge pump includes:

[0033] If the absolute value of the actual liquid level change rate is greater than or equal to the second liquid level change threshold, control the start of the main pressure discharge pump group;

[0034] If the absolute value of the actual liquid level change rate is greater than or equal to the first liquid level change threshold and less than the second liquid level change threshold, the auxiliary pressure discharge pump will be started.

[0035] When the main pressure discharge pump group or auxiliary pressure discharge pump is started, if the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is less than or equal to the first center of gravity threshold, the main pressure discharge pump group or auxiliary pressure discharge pump is stopped.

[0036] The second liquid level change threshold is 180 mm / h.

[0037] In one embodiment, determining the target ballast tank includes:

[0038] Obtain ballast tank level data;

[0039] Calculate the difference in liquid level distribution between the port and starboard ballast tanks to determine the actual direction of the center of gravity offset;

[0040] Choose a ballast tank on the side opposite to the current actual center of gravity offset direction.

[0041] The aforementioned automatic ballast and discharge control method for ships obtains the draft level data at the four corners of the ship, calculates the ship's stability parameters, determines whether to perform ballast or discharge operations, selects the main ballast and discharge pump set or auxiliary ballast and discharge pump, and opens the corresponding isolation valve of the target ballast tank until the ship returns to a stable state. Based on the actual operating conditions of the ship, the ballast and discharge operations are completed automatically and accurately, effectively improving the ship's stability, reducing manual intervention, and enhancing the safety and reliability of ship operation.

[0042] According to another object of the present invention, an automatic ballast removal device for ships is also provided, comprising:

[0043] The ballast tank assembly consists of multiple ballast tanks, symmetrically distributed on the port and starboard sides, with each ballast tank equipped with two liquid level sensors.

[0044] The ballast pump assembly includes multiple main ballast pump units and one auxiliary ballast pump. The inlet ends of the main and auxiliary ballast pump units are connected to the port and starboard seagates via connecting pipes. The outlet ends of the main and auxiliary ballast pump units are connected to each ballast tank via ballast ring pipes. The discharge ends of the main and auxiliary ballast pump units are connected to the port and starboard overboard discharge ports via pipelines.

[0045] The sensing unit includes multiple draft level sensors, which are installed at the four corners of the bow, stern, port side, and starboard side of the ship.

[0046] The control unit includes:

[0047] Equipped with a computer, and connected to the liquid level sensors in each compartment and the draft sensors at the four corners;

[0048] The central control unit is connected in communication with the onboard computer;

[0049] The pump motor control center receives instructions from the central control unit and controls the operation of the ballast pump group and the isolation valves installed between each ballast tank and the ballast ring pipe.

[0050] In one embodiment, the loading computer is configured to receive draft level data at the four corners or ballast tank level data, calculate the sign of the difference between the ship's actual center of gravity and the theoretical center of gravity, compare the absolute value of the difference with a first center of gravity threshold and a second center of gravity threshold, or calculate the sign of the actual liquid level change rate, and compare the absolute value of the actual liquid level change rate with a first liquid level change threshold and a second liquid level change threshold.

[0051] The aforementioned automatic ballast removal device can automatically and accurately perform ballast removal operations based on the actual stability of the ship, rationally select ballast pump sets and target ballast tanks, and effectively improve the safety and reliability of the ship in complex marine environments. Attached Figure Description

[0052] Figure 1 A flowchart illustrating the automatic ballast removal control method for ships. Figure 1 .

[0053] Figure 2 A flowchart illustrating the automatic ballast removal control method for ships. Figure 2 .

[0054] Figure 3 A flowchart illustrating the automatic ballast removal control method for ships. Figure 3 .

[0055] Figure 4 This is a schematic diagram of the principle of an automatic ballast removal device for ships.

[0056] In the diagram: 10. Draft level sensor; 20. Ballast tank; 21. Level sensor; 30. Main ballast pump assembly; 31. Auxiliary ballast pump; 32. Pump motor control center; 40. Isolation valve; 50. Loading computer; 60. Central control unit; 70. Subsea door; 80. Outboard discharge port. Detailed Implementation

[0057] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0058] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0059] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0060] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0061] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0062] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0063] Traditional automatic ballast water control technology based on sea state monitoring monitors sea state through an environmental sensor network, inputs the data into the control system, calculates the liquid level adjustment scheme using a preset algorithm model, and automatically executes the adjustment operation. However, this control logic relies excessively on external sea state parameters and fails to effectively identify the dynamically changing loading conditions during actual ship operation, especially the complex operating scenarios of marine engineering vessels. Secondly, the existing system's control model fails to capture the essential parameters of ship stability adjustment, resulting in system response lag and insufficient accuracy.

[0064] See Figure 1 , Figure 1 A flowchart illustrating an embodiment of the automatic ballast removal control method for ships is shown.

[0065] To address the aforementioned technical problems, this application provides an embodiment of an automatic ballast removal control method for ships, enabling ships to automatically, accurately, and efficiently complete ballast removal operations under complex working conditions, thereby ensuring ship stability.

[0066] In this embodiment, the automatic ballast removal control method for ships includes:

[0067] Step S1: Acquire real-time draft level data at the four corners of the ship;

[0068] Step S2: Calculate ship stability parameters based on data;

[0069] Step S3: Determine whether to perform ballast operation or de-ballast operation based on stability parameters, and select the main ballast / de-ballast pump group 30 or the auxiliary ballast / de-ballast pump 31.

[0070] Step S4: Determine the target ballast tank 20 and control the opening of the corresponding isolation valve 40;

[0071] Step S5: Control the selected pump set to perform ballast or discharge operations.

[0072] Automatic ballast control methods are applied to various types of ships equipped with ballast systems, especially marine engineering vessels such as floating production storage and offloading (FPSO) and floating liquefied natural gas (FLNG) production storage and offloading (LNG) units. These vessels often face complex loading conditions and variable sea conditions during operation, and have high requirements for stability control.

[0073] Draft level sensors 10 are installed at the four corners of the ship—bow, stern, port, and starboard—to measure the draft level data at each location in real time. The bow tank serves as the first ballast tank 20. Nine ballast tanks 20 are arranged sequentially on the port side, and nine ballast tanks 20 are arranged symmetrically on the starboard side. Each ballast tank 20 is equipped with a level sensor 21 to collect the level data in real time. The data collected by the sensors is transmitted to the loading computer 50 via signal lines. The control unit includes the loading computer 50 and a central control unit 60. The loading computer 50 calculates the ship's stability parameters based on this data, and the central control unit 60 selects either the main ballast pump group 30 or the auxiliary ballast pump 31 to perform ballast or unloading operations.

[0074] In step S1, the draft level sensor 10 continuously monitors the draft depth at the four corners of the ship. At the same time, it converts the collected analog signals into digital signals and transmits them to the loading computer 50 through data transmission lines such as fieldbus and Ethernet.

[0075] The computer 50 performs preliminary processing on the received data, including data filtering and noise reduction, to eliminate the influence of sensor measurement errors and external interference on the data, ensuring the accuracy and reliability of the acquired liquid level data. For example, a moving average filtering algorithm is used to smooth the data and remove random noise.

[0076] In step S2, the computer 50 calculates the ship's stability parameters using a pre-set mathematical model and algorithm based on the real-time acquired draft level data at the four corners of the ship. The stability parameters include the ship's actual center of gravity position and the rate of change of the ship's draft level.

[0077] In one implementation, the actual center of gravity of the ship is determined by integrating the ship's draft level data at its four corners, combined with information such as the ship's geometry, structural layout, and load distribution in each compartment. Specifically, the ship is divided into multiple small volume units, the center of gravity position and weight of each volume unit are calculated, and then a weighted average of the center of gravity positions of all volume units is taken to obtain the actual center of gravity position of the ship.

[0078] In another implementation, differential calculations are performed on the draft level data at the four corners of the ship collected at continuous time points to obtain the rate of change of the ship's draft level over time. The rate of change of draft level reflects the speed at which the ship's draft depth changes during navigation or operation.

[0079] In step S3, the central control unit 60 compares the calculated ship stability parameters with the set stability threshold, and determines whether the ship needs to perform ballast operation or unloading operation based on the comparison result.

[0080] If the actual center of gravity of a vessel deviates from its theoretical center of gravity by more than a set threshold, or if the rate of change of the vessel's draft exceeds the safe range, it indicates that the vessel's stability is affected and stability adjustments are required. When the actual center of gravity of the vessel is too high or the draft is too shallow, ballast operations are performed to increase the vessel's weight, lower the center of gravity, and improve stability. When the actual center of gravity of the vessel is too low or the draft is too deep, unloading operations are performed to reduce the vessel's weight, raise the center of gravity, and restore stability.

[0081] Depending on the required ballast or discharge flow rate and the urgency of the operation, either the main ballast or discharge pump set 30 or the auxiliary ballast or discharge pump 31 is selected. The main ballast or discharge pump set 30 typically has a larger flow rate and higher head, making it suitable for large-flow ballast or discharge operations and enabling it to complete stability adjustments in a short time. The auxiliary ballast or discharge pump 31 has a relatively smaller flow rate but features rapid start-up and flexible operation, making it suitable for small-flow or emergency ballast or discharge operations. For example, when a ship encounters sudden sea conditions requiring rapid stability adjustments, the main ballast or discharge pump set 30 is preferred; while for routine stability fine-tuning or partial adjustments to some ballast tanks 20, the auxiliary ballast or discharge pump 31 can be selected.

[0082] In step S4, based on the ballast or discharge operation type determined in step S3, and in combination with the liquid level distribution and stability adjustment requirements of each ballast tank 20 of the ship, the target ballast tank 20 that needs to be ballasted or discharged is determined.

[0083] When performing ballast operations, the ballast tank 20 with a lower liquid level and closer to the ship's center of gravity is selected as the target ballast tank 20 to quickly and effectively lower the ship's center of gravity and improve stability. When performing unloading operations, the ballast tank 20 with a higher liquid level and less impact on the ship's stability is selected as the target ballast tank 20 to reduce the ship's weight while minimizing adverse effects on the overall stability of the ship.

[0084] The central control unit 60 generates a corresponding control command to open the isolation valve 40 based on the determined target ballast tank 20. This command is sent to the actuator of the isolation valve 40 corresponding to the target ballast tank 20 via a data transmission line, controlling the isolation valve 40 to open and connect the target ballast tank 20 with the selected pump set to enable subsequent ballasting or unloading operations.

[0085] In step S5, the central control unit 60 sends a start control command to the selected main pressure ballast pump group 30 or auxiliary pressure ballast pump 31 to control the pump group to start working and perform pressure ballast or pressure discharge operations.

[0086] During ballast operations, the main ballast pump unit 30 or the auxiliary ballast pump 31 pumps external seawater into the target ballast tank 20 through pipelines. Throughout the ballast process, the draft level data at the four corners of the vessel is continuously monitored. Based on the real-time monitored data, the operating parameters of the ballast pumps, such as flow rate and pressure, are dynamically adjusted to ensure the ballast operation proceeds smoothly and to avoid problems such as uneven or excessive ballasting.

[0087] During ballast removal operations, the main ballast removal pump unit 30 or the auxiliary ballast removal pump 31 discharges seawater from the target ballast tank 20 to the outside of the ship through pipelines. Similarly, during the ballast removal process, relevant data is monitored in real time, and the pump unit operating parameters are adjusted according to data changes to ensure the stability of the ballast removal operation.

[0088] The onboard computer 50 compares the ship's stability parameters calculated in real time with the preset stability target values. When the ship's actual center of gravity returns to near the theoretical center of gravity, the ship's rate of change of draft is within a safe range, and the liquid level distribution in each ballast tank 20 is reasonable, it is determined that the ship has returned to a stable state. At this time, the central control unit 60 sends a stop control command to the selected pump group, controlling the pump group to stop working and closing the isolation valve 40 corresponding to the target ballast tank 20, thus completing this ballast discharge operation.

[0089] As mentioned above, the automatic ballast removal control method can automatically and accurately complete ballast removal operations according to the actual operating conditions of the ship, effectively improving the stability of the ship, reducing manual intervention, and enhancing the safety and reliability of ship operation.

[0090] Combination Figure 2 As shown, Figure 2 This is a flowchart illustrating the automatic ballast removal control method for ships provided in one embodiment of this application.

[0091] In some embodiments, the stability parameter is the difference between the actual center of gravity and the theoretical center of gravity. Step S3, which determines whether to perform ballast or unloading operations, further includes the steps: S31, performing ballast operations when the difference between the actual center of gravity and the theoretical center of gravity is positive; and performing unloading operations when the difference between the actual center of gravity and the theoretical center of gravity is negative.

[0092] Specifically, the difference between the actual center of gravity and the theoretical center of gravity is calculated, which is the actual center of gravity coordinates minus the theoretical center of gravity coordinates. When the calculated difference is positive, it indicates that the ship's actual center of gravity is higher than the theoretical center of gravity, and the ship's stability is reduced. At this time, ballast operation is automatically determined.

[0093] When the difference is negative, it indicates that the ship's actual center of gravity is lower than its theoretical center of gravity. If the center of gravity is too low, it may affect the ship's maneuverability and seaworthiness, and a loading operation will be carried out.

[0094] When performing ballast operations, based on the liquid level of each ballast tank 20 in the port and starboard compartments, select the ballast tank 20, open the corresponding isolation valve 40, and start the main ballast pump group 30 or auxiliary ballast pump 31 to inject seawater into the target ballast tank 20, thereby increasing the ship's weight and lowering its center of gravity until the difference between the actual center of gravity and the theoretical center of gravity returns to a reasonable range.

[0095] When performing the ballast operation, select ballast tank 20 with a higher liquid level and less impact on the stability of the ship, open the isolation valve 40, and start the ballast pump to discharge the seawater in the tank, thereby reducing the weight of the ship, raising the center of gravity, and restoring the stability of the ship.

[0096] In one embodiment, step S3, which determines whether to perform ballast or unloading operation, further includes the step: S311, when the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to a first center of gravity threshold, perform ballast or unloading operation.

[0097] Specifically, the first center of gravity threshold for a ship is 300mm. If the absolute value of the difference between the actual and theoretical center of gravity is greater than or equal to 300mm, it indicates a significant shift in the ship's center of gravity, affecting its stability and requiring ballast or unloading operations. If the absolute value of the difference between the actual and theoretical center of gravity is less than 300mm, then ballast or unloading operations are not required.

[0098] If the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is less than the first center of gravity threshold, then no ballast or unloading operation will be performed.

[0099] In one embodiment, step S3, in selecting the main pressure venting pump group 30 or the auxiliary pressure venting pump 31, further includes the step: S33, if the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to the second center of gravity threshold, control the start of the main pressure venting pump group 30.

[0100] Specifically, the second center of gravity threshold is 500mm. If the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to 500mm, it indicates that the stability of the ship is seriously affected, and ballast or unloading operations need to be carried out quickly and extensively, and the main ballast and unloading pump unit 30 should be started.

[0101] In one embodiment, step S3, in selecting the main pressure displacement pump group 30 or the auxiliary pressure displacement pump 31, further includes the step: S34, if the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to the first center of gravity threshold and less than the second center of gravity threshold, control the start of the auxiliary pressure displacement pump 31.

[0102] Specifically, if the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to 300 mm but less than 500 mm, it indicates that there is a certain problem with the stability of the FPSO, but the adjustment requirement is relatively small, and the auxiliary pressure discharge pump 31 is controlled to start.

[0103] Based on the pump selection result, a start command is sent to the corresponding ballast pump, the isolation valve 40 of the target ballast tank 20 is opened, and the pump set is controlled to operate.

[0104] During ballast or de-ballasting processes triggered by the absolute value of the difference between the actual and theoretical center of gravity, the ship's center of gravity and draft / level data are monitored in real time. Simultaneously, the aforementioned center of gravity control and level change rate control programs are disabled. When the absolute value of the difference between the actual and theoretical center of gravity is detected to be less than the third center of gravity threshold (i.e., less than 10 mm), the ballast or de-ballasting procedure is stopped, the main or auxiliary ballast / de-ballasting pump unit is stopped, and the center of gravity control and level change rate control programs are reactivated.

[0105] Combination Figure 3 As shown, Figure 3 This is another flowchart illustrating the automatic ballast removal control method for ships provided in one embodiment of this application.

[0106] In some embodiments, the stability parameter is the difference between the actual liquid level change rate and the theoretical change rate. Step S3, which determines whether to perform ballast or discharge operations, further includes the step: S32, performing ballast operation when the actual liquid level change rate is negative; and performing discharge operation when the actual liquid level change rate is positive.

[0107] Specifically, the actual rate of change of the water level is calculated by performing differential calculations on the water level data continuously collected at the four corners of the ship.

[0108] When the actual rate of change of liquid level is negative, it indicates that the actual draft of the ship is dropping rapidly, which may be due to the ship tilting or the draft being too shallow in some areas, thus threatening the stability of the ship. Therefore, it is determined that ballast operation should be performed.

[0109] When the actual rate of change of liquid level is positive, it indicates that the actual draft of the ship is rising rapidly, which may indicate that the ship is overloaded or has excessive draft in some areas, affecting the safety of navigation. Therefore, it is determined that a dredging operation should be carried out.

[0110] When performing ballast operations, based on the current liquid level distribution of each ballast tank 20, determine which ballast tank 20 needs to be injected with seawater, open the corresponding isolation valve 40, start the main ballast pump group 30 or the auxiliary ballast pump 31 to perform ballast and adjust the ship's draft level.

[0111] When performing the ballast operation, select the corresponding ballast tank 20, open the isolation valve 40 and the main ballast pump group 30 or the auxiliary ballast pump 31 to discharge some seawater, reduce the ship's draft, and stabilize the ship's attitude.

[0112] Step S3, which determines whether to perform ballast or discharge operation, further includes the step S321: When the absolute value of the actual liquid level change rate is greater than or equal to the first liquid level change threshold, perform ballast or discharge operation.

[0113] Specifically, the first liquid level change threshold is 20 mm / h. Calculate the absolute value of the actual liquid level change rate. When the absolute value of this difference is greater than or equal to 20 mm / h, it indicates an abnormal change in the platform's draft level, and ballast or discharge operations should be performed.

[0114] If the absolute value of the actual liquid level change rate is less than 20 mm / h, ballast or discharge operations are not required.

[0115] In one embodiment, step S3, in selecting the main pressure venting pump group 30 or the auxiliary pressure venting pump 31, further includes the step: S33, if the absolute value of the actual liquid level change rate is greater than or equal to the second liquid level change threshold, control the start of the main pressure venting pump group 30.

[0116] Specifically, the second liquid level change threshold is 180 mm / h. If the absolute value of the actual liquid level change rate is greater than or equal to 180 mm / h, it indicates that the stability of the ship is severely affected, and rapid and large-scale ballast or unloading operations are required, controlling the start of the main ballast and unloading pump group 30.

[0117] In one embodiment, step S3, in selecting the main pressure venting pump group 30 or the auxiliary pressure venting pump 31, further includes the step: S34, if the absolute value of the actual liquid level change rate is greater than or equal to the first liquid level change threshold and less than the second liquid level change threshold, control the start of the auxiliary pressure venting pump 31.

[0118] Specifically, if the absolute value of the actual liquid level change rate is greater than or equal to 20 mm / h and less than 180 mm / h, it indicates that there is a certain problem with the stability of the FPSO, but the adjustment requirement is relatively small, and the auxiliary pressure discharge pump 31 is started.

[0119] Based on the pump selection result, a start command is sent to the corresponding ballast pump, the isolation valve 40 of the target ballast tank 20 is opened, and the pump set is controlled to operate.

[0120] During ballasting or unloading, the ship's center of gravity and liquid level data are monitored in real time. Simultaneously, the liquid level change rate control program and the center of gravity control program are kept online. When the absolute value of the difference between the actual and theoretical center of gravity is detected to be less than or equal to the first center of gravity threshold (i.e., less than or equal to 300 mm), the ballasting or unloading program is stopped, and the main or auxiliary ballasting / unloading pump unit is shut down.

[0121] In this embodiment, during ballasting or unloading, the liquid level change rate control program or the center of gravity control program needs to be kept online to monitor the absolute value change of the difference between the ship's actual center of gravity and the theoretical center of gravity in real time. It is understood that if the rate of change of the draft at the four corners of the ship is 100 mm / h, and its absolute value is greater than 20 mm / h but less than 180 mm / h, the auxiliary ballast pump is triggered to perform unloading operations, i.e., controlling the opening of the corresponding compartments to drain the water. If the center of gravity control program is disabled, the auxiliary ballast pump performs unloading operations at a liquid level change rate of -30 mm / h, causing the center of gravity of the corresponding drained compartment to decrease, while the center of gravity of other compartments, due to the lack of drainage, relatively increases. This also increases the draft at other locations on the ship, leading to a growing difference between the actual and theoretical center of gravity, and a decreasing center of gravity in some locations, posing a risk of sinking. Therefore, during unloading, the center of gravity control program is kept online, and unloading operations are stopped when the absolute value of the difference between the actual and theoretical center of gravity is less than 300 mm.

[0122] If the liquid level change rate control program is disabled during unloading, the reduced cargo load will cause the liquid level rate at the four corners of the ship to reach -150 mm / h, theoretically triggering ballast operations. However, because the liquid level change rate program is disabled, unloading operations continue, causing the difference between the ship's actual center of gravity and the theoretical center of gravity to increase, resulting in a higher center of gravity in some compartments and a risk of capsizing. Therefore, during unloading, the liquid level change rate control program should be kept online, and unloading operations should be stopped when the absolute value of the difference between the actual and theoretical center of gravity is less than 300 mm.

[0123] In this embodiment, if the center of gravity control program and the liquid level change rate control program are triggered simultaneously, the center of gravity control program is selected first, that is, the center of gravity control program has a higher priority.

[0124] In one embodiment, step S4 of determining the target ballast tank 20 further includes the following steps: S41, acquiring the liquid level data of the ballast tank 20, calculating the difference in liquid level distribution between the port and starboard ballast tanks 20, determining the actual center of gravity offset direction, and selecting the side ballast tank 20 opposite to the current actual center of gravity offset direction.

[0125] Specifically, the liquid level sensor 21 acquires the liquid level data of the ballast tank 20 in real time, calculates the difference in liquid level distribution between the port and starboard ballast tanks 20, calculates the actual center of gravity position, and compares it with the theoretical center of gravity position to determine the offset direction of the actual center of gravity.

[0126] The loading computer 50 calculates the difference in liquid level distribution between the port and starboard ballast tanks 20 based on the difference in the average liquid levels of the corresponding ballast tanks 20 on the port and starboard sides, or by calculating the difference after weighted averaging of the liquid levels of each ballast tank 20. Based on the actual direction of the center of gravity shift, the ballast tank 20 on the side opposite to that direction is selected as the target ballast tank 20. For example, when the actual direction of the center of gravity shift is starboard, the ballast tank 20 on the port side is selected as the target ballast tank 20. If there are multiple ballast tanks 20 on the port side, the ballast tank 20 with the lower liquid level can be prioritized based on the magnitude of the difference in liquid level distribution to more effectively adjust the ship's center of gravity.

[0127] Combination Figure 4 As shown, Figure 4 This is a schematic diagram of the principle of an automatic ballast removal device for ships provided in one embodiment of this application. In some embodiments, an automatic ballast removal device for ships includes: 20 sets of ballast tanks, a ballast removal pump set, a sensing unit, and a control unit, which implements the above-described automatic ballast removal control method for ships.

[0128] In this embodiment, the ballast tank group 20 includes multiple ballast tanks 20, which are symmetrically distributed on the port and starboard sides. Specifically, the bow section of the ship serves as the first ballast tank 20, with nine ballast tanks 20 arranged sequentially on the port side and nine ballast tanks 20 symmetrically arranged on the starboard side. This symmetrical layout helps to better adjust the ship's center of gravity and maintain balance during ballast removal and unloading.

[0129] Two independent liquid level sensors 21 are used to detect single-point faults. When the difference between the readings of the two sensors is less than 1%, the liquid level data is considered valid. If the difference between the readings of the two sensors is greater than or equal to 1%, the liquid level data is considered incorrect, the automatic ballast operation is stopped, and an alarm message is issued. This avoids errors in the original data input caused by the failure of a single point of failure of the compartment liquid level sensor 21, thereby improving safety.

[0130] The ballast pump assembly comprises three main ballast pump units 30 and one auxiliary ballast pump 31. The inlet ends of the main ballast pump units 30 and the auxiliary ballast pump 31 are connected to the port and starboard seagates 70 via connecting pipes, facilitating the extraction of seawater from the seagates 70 on both sides of the vessel. The outlet ends of the main ballast pump units 30 and the auxiliary ballast pump 31 are connected to each ballast tank 20 via ballast ring pipes, enabling the ballast pump units to deliver seawater to designated ballast tanks 20. The discharge ends of the main ballast pump units 30 and the auxiliary ballast pump 31 are connected to the port and starboard overboard discharge ports 80 via pipelines. During ballast operations, the pump units discharge seawater from the ballast tanks 20 overboard through the overboard discharge ports 80, completing the ballast process.

[0131] The sensing unit includes four draft level sensors 10, which are installed at the four corners of the ship's bow, stern, port side, and starboard side, respectively. They can monitor the draft level at the four corners of the ship in real time and accurately reflect the ship's overall draft status and attitude through multi-point measurement.

[0132] The control unit includes a computer 50, a central control unit 60, and a pump motor control center 32.

[0133] The onboard computer 50 is communicatively connected to the liquid level sensors 21 in each compartment and the draft liquid level sensors 10 located at the four corners of the ship, receiving liquid level data transmitted from the sensors in real time. The onboard computer 50 is configured to receive draft liquid level data at the four corners or liquid level data in the ballast tanks, calculate the sign of the difference between the ship's actual center of gravity and the theoretical center of gravity, compare the absolute value of the difference with the magnitude of a first center of gravity threshold and a second center of gravity threshold, or calculate the sign of the actual liquid level change rate, and compare the absolute value of the actual liquid level change rate with the magnitude of a first liquid level change threshold and a second liquid level change threshold.

[0134] The central control unit 60 is communicatively connected to the loading computer 50, and is responsible for receiving the data processed by the loading computer 50 and making logical judgments and decisions according to the preset control strategy. For example, based on the difference between the ship's actual center of gravity and the theoretical center of gravity, and the sign of the rate of change of liquid level, it determines whether ballast or unloading operations need to be performed, and selects the appropriate main ballast unloading pump set 30 or auxiliary ballast unloading pump 31.

[0135] The pump motor control center 32 receives instructions from the central control unit 60 and controls the operation of the ballast pump group and the isolation valves 40 installed between each ballast tank 20 and the ballast ring pipe. When ballast or discharge operations are required, the pump motor control center 32 starts the corresponding ballast pump according to the instructions and opens the isolation valve 40 of the target ballast tank 20, so that seawater can be ballasted or discharged according to the predetermined path.

[0136] Loading computer 50 determines whether to perform ballast or deballast operation, or selects main ballast pump group 30 or auxiliary ballast pump 31. After the ship's operators check and confirm, the operators issue an authorization instruction, and then the loading computer 50 further controls the execution of the corresponding operation to avoid the risk of misjudgment or misoperation under complex working conditions.

[0137] When the absolute value of the difference between the theoretical and actual center of gravity is greater than or equal to the first center of gravity threshold (greater than or equal to 300 mm), the ship's center of gravity and draft level data are monitored in real time during ballast or unloading operations. Simultaneously, the aforementioned center of gravity control program and level change rate control program are disabled. It is understandable that if the difference between the theoretical and actual center of gravity is 1000 mm, triggering the main ballast pump unit to perform unloading operations, the level change rate will be negative due to unloading from the corresponding compartments. If its absolute value exceeds the second level change threshold, and the level change rate control program is online, the main ballast pump unit will be activated to perform ballast operations, contradicting the aforementioned unloading operations. Therefore, during ballast or unloading operations, the center of gravity control program and level change rate control program are disabled. When the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is less than the third center of gravity threshold, i.e. less than 10 mm, the control stops executing the ballast or unloading program, stops the main ballast pump or auxiliary ballast pump, and reactivates the center of gravity control program.

[0138] When the absolute value of the liquid level change rate is greater than or equal to the first liquid level change threshold (20 mm / h), the ship's center of gravity and liquid level data are monitored in real time during ballast or de-ballasting. Simultaneously, the liquid level change rate control program and the center of gravity control program are kept online. When the absolute value of the difference between the actual and theoretical center of gravity is less than or equal to the first center of gravity threshold (300 mm / h), the ballast or de-ballasting procedure is stopped, and the main or auxiliary ballast / de-ballasting pump unit is shut down.

[0139] As mentioned above, the automatic ballast removal device can automatically and accurately perform ballast removal operations according to the actual stability of the ship, and rationally select the ballast pump group and target ballast tank 20, effectively improving the safety and reliability of the ship in complex marine environments.

[0140] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0141] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for automatic ballast removal control of ships, characterized in that, include: Real-time acquisition of draft and liquid level data at the four corners of the ship; Calculate the ship's stability parameters based on the data; The ballast or de-ballast operation is determined based on the stability parameters, and the main ballast / de-ballast pump set or auxiliary ballast / de-ballast pump is selected. Identify the target ballast tank and control the opening of the corresponding isolation valve; Control the selected pump set to perform ballast or discharge operations; The stability parameter is the difference between the actual center of gravity and the theoretical center of gravity. The step of determining whether to perform ballast or unloading operation includes: performing ballast operation when the difference between the actual center of gravity and the theoretical center of gravity is positive; and performing unloading operation when the difference between the actual center of gravity and the theoretical center of gravity is negative. The stability parameter is the actual liquid level change rate. The determination of whether to perform ballast or discharge operation includes: performing ballast operation when the actual liquid level change rate is negative; and performing discharge operation when the actual liquid level change rate is positive. If the center of gravity control program and the liquid level change rate control program are triggered simultaneously, the center of gravity control program shall be selected first. The process of determining the target ballast tank includes: acquiring ballast tank liquid level data; calculating the difference in liquid level distribution between the port and starboard ballast tanks to determine the actual center of gravity offset direction; and selecting the ballast tank on the side opposite to the current actual center of gravity offset direction.

2. The automatic ballast discharge control method for ships according to claim 1, characterized in that, The determination to perform ballast or unloading operations includes: When the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to the first center of gravity threshold, ballast or unloading operations are performed. If the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is less than the first center of gravity threshold, then no ballast or unloading operation will be performed. The first centroid threshold is 300mm.

3. The automatic ballast discharge control method for ships according to claim 2, characterized in that, The selection of the main pressure relief pump group or the auxiliary pressure relief pump includes: If the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to the second center of gravity threshold, the main pressure discharge pump group will be started. If the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is greater than or equal to the first center of gravity threshold and less than the second center of gravity threshold, the auxiliary pressure discharge pump will be started. When the main ballast pump group or auxiliary ballast pump is started, if the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is less than the third center of gravity threshold, the main ballast pump group or auxiliary ballast pump is stopped. The second centroid threshold is 500mm, and the third centroid threshold is 10mm.

4. The automatic ballast discharge control method for ships according to claim 1, characterized in that, The determination to perform ballast or unloading operations includes: When the absolute value of the actual liquid level change rate is greater than or equal to the first liquid level change threshold, perform ballast or discharge operation. If the absolute value of the actual liquid level change rate is less than the first liquid level change threshold, then ballast or discharge operations will not be performed. The first liquid level change threshold is 20 mm / h.

5. The automatic ballast discharge control method for ships according to claim 4, characterized in that, The selection of the main pressure relief pump group or the auxiliary pressure relief pump includes: If the absolute value of the actual liquid level change rate is greater than or equal to the second liquid level change threshold, control the start of the main pressure discharge pump group; If the absolute value of the actual liquid level change rate is greater than or equal to the first liquid level change threshold and less than the second liquid level change threshold, the auxiliary pressure discharge pump will be started. When the main pressure discharge pump group or auxiliary pressure discharge pump is started, if the absolute value of the difference between the actual center of gravity and the theoretical center of gravity is less than or equal to the first center of gravity threshold, the main pressure discharge pump group or auxiliary pressure discharge pump is stopped. The second liquid level change threshold is 180 mm / h.

6. An automatic ballast removal device for ships, characterized in that, For implementing the automatic ballast removal control method for ships as described in any one of claims 1-5, comprising: The ballast tank assembly consists of multiple ballast tanks, symmetrically distributed on the port and starboard sides, with each ballast tank equipped with two liquid level sensors. The ballast pump assembly includes multiple main ballast pump units and one auxiliary ballast pump. The inlet ends of the main and auxiliary ballast pump units are connected to the port and starboard seagates via connecting pipes. The outlet ends of the main and auxiliary ballast pump units are connected to each ballast tank via ballast ring pipes. The discharge ends of the main and auxiliary ballast pump units are connected to the port and starboard overboard discharge ports via pipelines. The sensing unit includes multiple draft level sensors, which are installed at the four corners of the bow, stern, port side, and starboard side of the ship. The control unit includes: Equipped with a computer, and connected to the liquid level sensors in each compartment and the draft sensors at the four corners; The central control unit is connected in communication with the onboard computer; The pump motor control center receives instructions from the central control unit and controls the operation of the ballast pump group and the isolation valves installed between each ballast tank and the ballast ring pipe.

7. The automatic ballast removal device for ships according to claim 6, characterized in that, The loading computer is configured to receive draft level data at the four corners or ballast tank level data, calculate the sign of the difference between the ship's actual center of gravity and the theoretical center of gravity, compare the absolute value of the difference with the magnitude of a first center of gravity threshold and a second center of gravity threshold, or calculate the sign of the actual liquid level change rate, and compare the absolute value of the actual liquid level change rate with the magnitude of a first liquid level change threshold and a second liquid level change threshold.

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