Control Method and Control Device for Liquid Cargo Handling System

Abstract

The present disclosure provides a control method and a control device for a liquid cargo handling system, belonging to the technical field of ships. The control method for the liquid cargo handling system includes: obtaining a switching instruction, where the switching instruction is used to indicate increasing the liquid cargo pump for discharging; controlling the rotational speed of the currently operating liquid cargo pump to decrease to a first rotational speed; controlling the rotational speed of the increased liquid cargo pump to increase to the first rotational speed; synchronously adjusting the rotational speeds of all the liquid cargo pumps until the pressure in the header meets the target pressure. The present disclosure can effectively avoid the problem that the header pressure will rapidly increase and exceed the pipeline pressure limit after increasing the liquid cargo pump, resulting in pipeline leakage, and improve the operating efficiency of the liquid cargo pump.

Description

Technical Field

[0001] The present disclosure relates to the technical field of ships, and particularly relates to a control method and a control device for a liquid cargo loading and unloading system. Background Art

[0002] A liquid cargo loading and unloading system is a device for transporting the liquid cargo stored in the liquid cargo hold of a ship to a storage tank at a port terminal. The liquid cargo loading and unloading system generally includes: a liquid cargo pump, a manifold, a control valve, and a control cabinet. The inlet of the liquid cargo pump is located in the liquid cargo hold of the ship, the outlet of the liquid cargo pump is connected to the manifold, the manifold is connected to the storage tank at the port terminal, and the control valve is arranged between the outlet of the liquid cargo pump and the manifold. The control cabinet includes a controller and a variable-frequency motor. The variable-frequency motor is used to drive the blades of the liquid cargo pump to rotate, and the controller drives the variable-frequency motor to rotate to drive the liquid cargo pump to operate.

[0003] In the related art, when unloading liquid cargo through a liquid cargo loading and unloading system, the rotation speed of the liquid cargo pump is usually adjusted until the rotation speed of the liquid cargo pump makes the manifold pressure reach the required pressure.

[0004] However, when it is necessary to add other liquid cargo pumps to work together midway, technicians need to repeatedly adjust the rotation speeds of different liquid cargo pumps to make the manifold pressure reach the required pressure. Moreover, the large differences in the rotation speeds of different liquid cargo pumps after adjustment are also not conducive to the stable unloading of liquid cargo by the liquid cargo loading and unloading system, affecting the operation efficiency. Summary of the Invention

[0005] Embodiments of the present disclosure provide a control method and a control device for a liquid cargo loading and unloading system, which can effectively avoid the problem that the manifold pressure will rapidly increase and exceed the pipeline pressure limit after adding a liquid cargo pump, resulting in pipeline leakage, and improve the operation efficiency of the liquid cargo pump. The technical solutions are as follows:

[0006] Embodiments of the present disclosure provide a control method for a liquid cargo loading and unloading system. The control method includes: obtaining a switching instruction, where the switching instruction is used to indicate adding a liquid cargo pump for unloading; controlling the rotation speed of the currently working liquid cargo pump to decrease to a first rotation speed; controlling the rotation speed of the added liquid cargo pump to increase to the first rotation speed; synchronously adjusting the rotation speeds of all the liquid cargo pumps until the pressure in the manifold meets the target pressure.

[0007] In one implementation manner of the embodiments of the present disclosure, after controlling the rotation speed of the added liquid cargo pump to increase to the first rotation speed, it includes: obtaining the first pressure and the pressure in the manifold in real time, where the first pressure is the pressure at the outlet of each of the added liquid cargo pumps; when each of the first pressures is not less than the pressure in the manifold, controlling the control valve at the outlet of the added liquid cargo pump to open.

[0008] In another implementation manner of the embodiment of the present disclosure, before obtaining the switching instruction, it further includes: obtaining a start instruction, where the start instruction includes a first quantity, an initial rotational speed, and an initial pressure; controlling the first quantity of liquid cargo pumps to increase the rotational speed until the pressure at the liquid outlet of each liquid cargo pump is not less than the initial pressure, and controlling the control valves at the liquid outlets of each liquid cargo pump to open.

[0009] In another implementation manner of the embodiment of the present disclosure, the start instruction further includes a target pressure, a speed regulation frequency, and a speed regulation amplitude. After controlling the control valves at the liquid outlets of each liquid cargo pump to open, it includes: if the pressure in the header is not greater than the target pressure, controlling the liquid cargo pumps to increase the rotational speed according to the speed regulation frequency and the speed regulation amplitude; if the pressure in the header is greater than the target pressure, controlling the liquid cargo pumps to decrease the rotational speed according to the speed regulation frequency and the speed regulation amplitude.

[0010] In another implementation manner of the embodiment of the present disclosure, the speed regulation frequency is 5HZ to 15HZ, and the speed regulation amplitude is 10rad / min to 30rad / min.

[0011] The embodiment of the present disclosure provides a control device for a liquid cargo loading and unloading system. The control device includes: a first acquisition module for acquiring a switching instruction, where the switching instruction is used to indicate to increase the unloading of the liquid cargo pump; a first control module for controlling the rotational speed of the currently working liquid cargo pump to decrease to a first rotational speed; controlling the rotational speed of the increased liquid cargo pump to rise to the first rotational speed; synchronously adjusting the rotational speeds of all the liquid cargo pumps until the pressure in the header meets the target pressure.

[0012] In another implementation manner of the embodiment of the present disclosure, the control device further includes: a second acquisition module and a second control module; after controlling the rotational speed of the increased liquid cargo pump to rise to the first rotational speed, the first acquisition module is used to acquire the first pressure and the pressure in the header in real time, where the first pressure is the pressure at the liquid outlet of each increased liquid cargo pump; the second control module is used to control the control valves at the liquid outlets of the increased liquid cargo pumps to open when each first pressure is not less than the pressure in the header.

[0013] In another implementation manner of the embodiment of the present disclosure, the control device further includes a third acquisition module and a third control module; before obtaining the switching instruction, the third acquisition module is used to acquire a start instruction, where the start instruction includes a first quantity, an initial rotational speed, and an initial pressure; the third control module is used to control the first quantity of liquid cargo pumps to increase the rotational speed until the pressure at the liquid outlet of each liquid cargo pump is not less than the initial pressure, and control the control valves at the liquid outlets of each liquid cargo pump to open.

[0014] In another implementation manner of the embodiments of the present disclosure, the start instruction further includes a target pressure, a speed regulation frequency, and a speed regulation amplitude; the third control module includes: a first control sub-module and a second control sub-module. After controlling the control valves at the liquid outlet ports of the liquid cargo pumps to open, the first control sub-module is configured to control the liquid cargo pumps to increase the rotational speed according to the speed regulation frequency and the speed regulation amplitude if the pressure in the manifold is not greater than the target pressure; the second control sub-module is configured to control the liquid cargo pumps to decrease the rotational speed according to the speed regulation frequency and the speed regulation amplitude if the pressure in the manifold is greater than the target pressure.

[0015] In another implementation manner of the embodiments of the present disclosure, the speed regulation frequency is 5HZ to 15HZ, and the speed regulation amplitude is 10rad / min to 30rad / min.

[0016] The beneficial effects brought by the technical solutions provided by the embodiments of the present disclosure at least include:

[0017] For the control method of the liquid cargo pump loading and unloading system provided by the embodiments of the present disclosure, after obtaining the switching instruction, first control the rotational speed of the currently working liquid cargo pump to decrease to the first rotational speed to reduce the pressure in the manifold; then control the rotational speed of the added liquid cargo pump to increase to the first rotational speed so that the pressure at the liquid outlet of the added liquid cargo pump can be more easily consistent with the pressure in the manifold. After the rotational speeds of the original working liquid cargo pump and the added liquid cargo pump are both the first rotational speed, control all the liquid cargo pumps to adjust the speed together until the pressure in the manifold meets the target pressure.

[0018] Compared with directly increasing the rotational speed of the added liquid cargo pump to the rotational speed of the original working liquid cargo pump without reducing the rotational speed of the original working liquid cargo pump, this method of reducing the speed first and then synchronously adjusting the speed can effectively avoid the problem that the manifold pressure will rapidly increase and exceed the pipeline pressure limit after adding the liquid cargo pump, resulting in pipeline leakage, and improve safety. At the same time, adjusting the rotational speeds of the original working liquid cargo pump and the added liquid cargo pump to be consistent can also avoid the situation that after the pressure at the liquid outlet of the added liquid cargo pump reaches the pressure in the manifold, the rotational speed of the added liquid cargo pump is inconsistent with the rotational speed of the original working liquid cargo pump, thereby reducing the operating efficiency of the liquid cargo pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 is a schematic diagram of a liquid cargo loading and unloading system provided by the embodiments of the present disclosure;

[0021] Figure 2 It is a flowchart of a control method for a liquid cargo loading and unloading system provided by an embodiment of the present disclosure;

[0022] Figure 3 It is a flowchart of another control method for a liquid cargo loading and unloading system provided by an embodiment of the present disclosure;

[0023] Figure 4 It is a structural block diagram of a control device for a liquid cargo loading and unloading system provided by an embodiment of the present disclosure;

[0024] Figure 5 It is a structural block diagram of a computer device provided by an embodiment of the present disclosure. Detailed implementation manners

[0025] To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following will further describe the embodiments of the present disclosure in detail with reference to the accompanying drawings.

[0026] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present disclosure pertains. The "first", "second", "third", and similar terms used in the specification and claims of the present patent application do not denote any order, quantity, or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "one" do not denote a quantity limitation, but mean that there is at least one. The terms "including" or "comprising" and the like are intended to cover the elements or items listed after the "including" or "comprising" and their equivalents, and do not exclude other elements or items. The terms "connected" or "coupled" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", "top", "bottom", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0027] Figure 1 It is a schematic diagram of a liquid cargo loading and unloading system provided by an embodiment of the present disclosure. As Figure 1 shown, the liquid cargo loading and unloading system includes: a liquid cargo pump 10, a manifold 20, a control valve 30, and a control cabinet 40. The inlet of the liquid cargo pump 10 is located in the liquid cargo hold 50 of the ship. The outlet of the liquid cargo pump 10 is connected to the manifold 20, and the manifold 20 is then connected to the storage tank 60 of the port terminal. The control valve 30 is arranged between the outlet of the liquid cargo pump 10 and the manifold 20. The control cabinet includes a controller and a variable-frequency motor. The variable-frequency motor is used to drive the blades of the liquid cargo pump to rotate, and the controller drives the variable-frequency motor to rotate to drive the liquid cargo pump to operate.

[0028] Among them, the controller can be a Programmable Logic Controller (PLC for short).

[0029] The process of the cargo pump unloading the liquid cargo is as follows: The controller controls the cargo pump to start working, and the cargo pump pumps the liquid cargo in the cargo tank; at the same time, the pressure at the liquid outlet of the cargo pump is obtained. When the pressure at the liquid outlet of the cargo pump reaches the set value, the control valve at the liquid outlet of the cargo pump is controlled to open, so that the liquid cargo flows into the manifold and is transported to the storage tank through the manifold.

[0030] In the related art, there is usually a need to increase the liquid cargo unloading speed during the process of unloading the liquid cargo. Therefore, during the unloading process, additional cargo pumps are often added to work together. When adding cargo pumps, the speed of the added cargo pumps is usually gradually increased until the pressure at the liquid outlet of the added cargo pumps is balanced with the pressure in the manifold. This easily leads to the problem that the speeds of the original working cargo pump and the added cargo pumps are inconsistent, thereby reducing the operating efficiency of the cargo pump. Moreover, when adding cargo pumps during the speed increase process, there is also an easy problem of excessive pipeline pressure causing leakage.

[0031] Figure 2 It is a flowchart of a control method for a liquid cargo loading and unloading system provided by an embodiment of the present disclosure. As Figure 2 shown, the control method of the liquid cargo loading and unloading system is executed by the controller of the control cabinet and includes:

[0032] Step 101: Obtain a switching instruction.

[0033] Among them, the switching instruction is used to indicate adding a cargo pump to unload the cargo.

[0034] Step 102: Control the speed of the currently working cargo pump to decrease to the first speed.

[0035] Step 103: Control the speed of the added cargo pump to increase to the first speed.

[0036] Step 104: Synchronously adjust the speeds of all the cargo pumps until the pressure in the manifold meets the target pressure.

[0037] Among them, the target pressure can be the pipeline pressure limit of the storage tank.

[0038] The control method of the liquid cargo pump loading and unloading system provided by the embodiments of the present disclosure, after obtaining a switching instruction, first controls the rotational speed of the currently operating liquid cargo pump to decrease to a first rotational speed to reduce the pressure in the manifold; then controls the rotational speed of the added liquid cargo pump to increase to the first rotational speed so that the pressure at the liquid outlet of the added liquid cargo pump can more easily match the pressure in the manifold. After the rotational speeds of the originally operating liquid cargo pump and the added liquid cargo pump are both the first rotational speed, controls all the liquid cargo pumps to adjust their speeds together until the pressure in the manifold meets the target pressure.

[0039] Compared with directly increasing the rotational speed of the added liquid cargo pump to the rotational speed of the originally operating liquid cargo pump without reducing the rotational speed of the originally operating liquid cargo pump, this method of reducing the speed first and then synchronously adjusting the speed can effectively avoid the problem that the manifold pressure will rapidly increase and exceed the pipeline pressure limit after adding the liquid cargo pump, resulting in pipeline leakage, and improve safety. At the same time, adjusting the rotational speeds of the originally operating liquid cargo pump and the added liquid cargo pump to be consistent can also avoid the situation where after the pressure at the liquid outlet of the added liquid cargo pump reaches the pressure in the manifold, the rotational speed of the added liquid cargo pump is inconsistent with the rotational speed of the originally operating liquid cargo pump, thereby reducing the operating efficiency of the liquid cargo pump.

[0040] Figure 3 It is a flowchart of another control method of the liquid cargo loading and unloading system provided by the embodiments of the present disclosure. As Figure 3 shown, the control method of this liquid cargo loading and unloading system is executed by the controller of the control cabinet and includes:

[0041] Step 201: Obtain a start instruction.

[0042] Among them, the start instruction includes a first quantity, an initial rotational speed, and an initial pressure.

[0043] In the embodiments of the present disclosure, each liquid cargo tank is equipped with a liquid cargo pump, the first quantity is determined according to the number of liquid cargo tanks, and the first quantity can be 1 / 6 to 1 / 2 of the number of liquid cargo tanks.

[0044] Exemplarily, if there are 12 liquid cargo tanks on a ship and 12 liquid cargo pumps are configured corresponding to the 12 liquid cargo tanks, and the first quantity is 1 / 6 of the number of liquid cargo tanks, then it can be determined that the first quantity is 2.

[0045] Among them, both the initial rotational speed and the initial pressure can be data manually input by technicians.

[0046] Exemplarily, the control cabinet can also be provided with a human-machine interaction device, and the human-machine interaction device is connected to the controller. For example, the human-machine interaction device can be a touch screen, and technicians can input the determined first quantity, initial rotational speed, and initial pressure manually to input a start instruction to the controller.

[0047] Step 202: Control a first quantity of liquid cargo pumps to increase their speeds until the pressures at the liquid outlets of each liquid cargo pump are not less than the initial pressure, and control the control valves at the liquid outlets of each liquid cargo pump to open.

[0048] In the embodiments of the present disclosure, a pressure sensor is provided at the position of the liquid outlet of the liquid cargo pump. The pressure sensor is electrically connected to the controller, and the control valve is also electrically connected to the controller, so that the controller can control the opening and closing of the control valve based on the acquired pressure.

[0049] Steps 201 to 202 are the startup stage of the liquid cargo loading and unloading system:

[0050] In the startup stage, first set the first quantity, the initial speed, and the initial pressure on the touch screen, and then select the liquid cargo pumps that need to unload the cargo.

[0051] For example, when the first quantity is 2, one liquid cargo pump on the starboard side and one liquid cargo pump on the port side of the ship can be selected.

[0052] Exemplarily, the initial pressure can be from 0.5 bar to 1.5 bar. For example, the initial pressure is 1 bar.

[0053] Optionally, before controlling the liquid cargo pump to work, it can be first determined whether there are faults in the variable-frequency motor and the controller. If at least one of the variable-frequency motor and the controller fails, a pop-up window will prompt the fault of the variable-frequency motor and / or the controller on the touch screen. If both the variable-frequency motor and the controller are normal, then execute Step 202.

[0054] Optionally, the startup instruction further includes a target pressure, a speed regulation frequency, and a speed regulation amplitude.

[0055] Among them, the target pressure can be the pipeline limit pressure of the storage tank.

[0056] Exemplarily, the limit pressure of the pipeline for transporting liquid cargo in the storage tank does not exceed 8 bar. For example, the pipeline limit pressure is 6 bar.

[0057] Among them, the speed regulation frequency is from 5 HZ to 15 HZ, and the speed regulation amplitude is from 10 rad / min to 30 rad / min.

[0058] Exemplarily, the speed regulation frequency is 10 HZ, and the speed regulation amplitude is 20 rad / min.

[0059] After the startup stage of the liquid cargo loading and unloading system is completed, since the control valve is opened, the liquid cargo in the liquid cargo pump will flow into the header. At this time, the pressure at the liquid outlet of the liquid cargo pump will decrease, and the pressure in the header will gradually increase. At this time, the liquid cargo loading and unloading system enters the speed-up stage.

[0060] In the speed-up stage, first adjust the speed of the liquid cargo pump to control the pressure in the header to be maintained at the initial pressure ± error value.

[0061] Among them, the error value can be from 0.2 bar to 0.5 bar.

[0062] When the pressure in the header exceeds the sum of the initial pressure and the error value, control the cargo pump to reduce the rotational speed according to the speed regulation frequency and the speed regulation amplitude.

[0063] When the pressure in the header does not exceed the difference between the initial pressure and the error value, control the cargo pump to reduce the rotational speed according to the speed regulation frequency and the speed regulation amplitude.

[0064] Among them, a pressure sensor is provided in the header, and the pressure sensor is electrically connected to the controller, so that the controller controls the speed regulation of the cargo pump based on the acquired pressure.

[0065] After maintaining the pressure in the header at the initial pressure ± the set time of the error value, then execute the following steps 203 and 204. In this way, maintaining the pressure of the header near the initial pressure during the speed-up stage is beneficial for sampling. And perform a trial run at low pressure to observe whether the liquid cargo loading and unloading system can work normally, which can improve safety.

[0066] Step 203: If the pressure in the header is not greater than the target pressure, control the cargo pump to increase the rotational speed according to the speed regulation frequency and the speed regulation amplitude.

[0067] Exemplarily, the target pressure is 6 bar, the speed regulation frequency is 10 HZ, and the speed regulation amplitude is 20 rad / min. If the pressure in the header is less than 6 bar, control the cargo pump to increase the rotational speed at a frequency of 10 HZ and a step size of 20 rad / min.

[0068] Step 204: If the pressure in the header is greater than the target pressure, control the cargo pump to reduce the rotational speed according to the speed regulation frequency and the speed regulation amplitude.

[0069] Exemplarily, the target pressure is 6 bar, the speed regulation frequency is 10 HZ, and the speed regulation amplitude is 20 rad / min. If the pressure in the header is greater than 6 bar, control the cargo pump to reduce the rotational speed at a frequency of 10 HZ and a step size of 20 rad / min.

[0070] Through steps 203 to 204, the pressure in the header can be controlled to gradually approach the target pressure, and when the pressure in the header reaches the target pressure, the pressure in the header can also be controlled to be maintained near the target pressure.

[0071] In the embodiment of the present disclosure, during the unloading process of the liquid cargo loading and unloading system, if it is necessary to add a cargo pump to work together midway, the liquid cargo loading and unloading system can enter the switching stage.

[0072] Step 205: Obtain a switching instruction.

[0073] Among them, the switching instruction is used to indicate increasing the unloading of the liquid cargo pump.

[0074] In the embodiments of the present disclosure, the switching instruction may include the second quantity of the liquid cargo pumps that need to be increased. For example, the second quantity may be 1 to 4.

[0075] Exemplarily, a technician can input the determined second quantity manually to input the switching instruction to the controller.

[0076] Step 206: Control the rotational speed of the currently working liquid cargo pump to decrease to the first rotational speed.

[0077] Exemplarily, the first rotational speed may be 500 rad / min to 1500 rad / min. For example, the first rotational speed may be 1000 rad / min.

[0078] Reducing the rotational speed of the liquid cargo pump to the first rotational speed can reduce the pressure in the header before adding the increased liquid cargo pump, and avoid the problem that the pressure in the header exceeds the pipeline pressure limit after adding the liquid cargo pump, resulting in pipeline leakage, thereby improving safety.

[0079] Step 207: Control the rotational speed of the increased liquid cargo pump to rise to the first rotational speed.

[0080] Among them, when increasing the rotational speed of the liquid cargo pump, the rotational speed of the liquid cargo pump can be controlled to increase according to the speed regulation frequency and the speed regulation amplitude.

[0081] Exemplarily, the speed regulation frequency is 10 HZ, and the speed regulation amplitude is 20 rad / min. Control the increased liquid cargo pump to increase the rotational speed at a frequency of 10 HZ and a step size of 20 rad / min until the rotational speed reaches 1000 rad / min.

[0082] Step 208: Obtain the first pressure and the pressure in the header in real time.

[0083] Among them, the first pressure is the pressure at the liquid outlet of each of the increased liquid cargo pumps.

[0084] Step 209: When each first pressure is not less than the pressure in the header, control the control valve at the liquid outlet of the increased liquid cargo pump to open.

[0085] When the pressure at the liquid outlet of each liquid cargo pump is not less than the pressure in the header, open the control valve at the liquid outlet of the increased liquid cargo pump to avoid the liquid cargo in the header flowing back to the liquid cargo pump due to the too small pressure at the liquid outlet of the liquid cargo pump.

[0086] Step 210: Synchronously adjust the rotational speeds of all the liquid cargo pumps until the pressure in the header meets the target pressure.

[0087] Exemplarily, the first quantity is 2, the second quantity is 2, the target pressure is 6 bar, the speed regulation frequency is 10 HZ, and the speed regulation amplitude is 20 rad / min.

[0088] Step 210 may include synchronously adjusting the rotation speeds of 4 liquid cargo pumps at a frequency of 10 HZ and a step size of 20 rad / min until the pressure in the manifold reaches 6 bar.

[0089] Finally, after the liquid cargo unloading is completed, the liquid cargo handling system enters the shutdown phase, and the control liquid cargo pump stops working. Among them, first close the control valve at the liquid outlet of the stopped liquid cargo pump, and then control the liquid cargo pump to stop.

[0090] In the embodiments of the present disclosure, the prerequisite for implementing the control method of the liquid cargo handling system is that the control valve of the liquid cargo pump is remotely adjustable, and the pressure at the liquid outlet of the liquid cargo pump and the manifold pressure can be monitored in real time. This requires establishing communication with the valve remote control device and the pressure test device, and at the same time, there are quite high requirements for the communication delay time of the valve remote control device and the pressure test device and the control accuracy of the valve.

[0091] Exemplarily, the communication delay of the valve remote control and pressure test cannot be higher than 0.1 S; the control accuracy of the valve remote control device cannot be lower than 2%, and the valve failure rate cannot be higher than 0.1%.

[0092] Among them, the internal network of the liquid cargo handling system uses a Profinet ring network, which has good network redundancy performance, real-time performance, and high reliability; the communication devices for external interfaces such as pressure test and valve remote control use the ModbusTCP communication protocol, and a firewall gateway is adopted to ensure the interaction speed and security of communication with the liquid level telemetry and valve remote control devices.

[0093] Figure 4 It is a structural block diagram of a control device for a liquid cargo handling system provided by an embodiment of the present disclosure. As Figure 4 shown, the control device includes: a first acquisition module 310 and a first control module 320.

[0094] Among them, the first acquisition module 310 is used to acquire a switching instruction, and the switching instruction is used to indicate increasing the unloading of the liquid cargo pump; the first control module 320 is used to control the rotation speed of the currently working liquid cargo pump to decrease to the first rotation speed; control the rotation speed of the increased liquid cargo pump to increase to the first rotation speed; synchronously adjust the rotation speeds of all the liquid cargo pumps until the pressure in the manifold meets the target pressure.

[0095] Optionally, the control device further includes: a second acquisition module 330 and a second control module 340; after the control device increases the rotational speed of the added liquid cargo pump to the first rotational speed, the first acquisition module is configured to acquire the first pressure and the pressure in the manifold in real time, where the first pressure is the pressure at the liquid outlet of each added liquid cargo pump; the second control module is configured to control the control valve at the liquid outlet of the added liquid cargo pump to open when each first pressure is not less than the pressure in the manifold.

[0096] Optionally, the control device further includes a third acquisition module 350 and a third control module 360; before acquiring the switching instruction, the third acquisition module is configured to acquire a start instruction, where the start instruction includes a first quantity, an initial rotational speed, and an initial pressure; the third control module is configured to control the first quantity of liquid cargo pumps to increase the rotational speed until the pressure at the liquid outlet of each liquid cargo pump is not less than the initial pressure, and control the control valve at the liquid outlet of each liquid cargo pump to open.

[0097] Optionally, the start instruction further includes a target pressure, a speed regulation frequency, and a speed regulation amplitude; the third control module 360 includes: a first control sub-module 361 and a second control sub-module 362. After controlling the control valve at the liquid outlet of each liquid cargo pump to open, the first control sub-module is configured to control the liquid cargo pump to increase the rotational speed according to the speed regulation frequency and the speed regulation amplitude if the pressure in the manifold is not greater than the target pressure; the second control sub-module is configured to control the liquid cargo pump to decrease the rotational speed according to the speed regulation frequency and the speed regulation amplitude if the pressure in the manifold is greater than the target pressure.

[0098] Optionally, the speed regulation frequency is 5HZ to 15HZ, and the speed regulation amplitude is 10rad / min to 30rad / min.

[0099] Figure 5 It is a structural block diagram of a computer device provided by an embodiment of the present disclosure. As Figure 5 shown, the computer device includes: a processor 501 and a memory 502.

[0100] The processor 501 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 501 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), or PLA (Programmable Logic Array). The processor 501 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the wake state, also known as the CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 501 may be integrated with a GPU (Graphics Processing Unit), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 501 may further include an AI (Artificial Intelligence) processor, and the AI processor is used to process computational operations related to machine learning.

[0101] The memory 502 may include one or more computer-readable storage media, and the computer-readable storage media may be non-transitory. The memory 502 may further include high-speed random access memory and non-volatile memory, such as one or more disk storage devices and flash storage devices. In some embodiments, the non-transitory computer-readable storage media in the memory 502 is used to store at least one instruction, and the at least one instruction is used to be executed by the processor 501 to implement the control method of the liquid cargo handling system provided in the method embodiment of the present application.

[0102] In some embodiments, the computer device may further optionally include: a peripheral device interface 503 and at least one peripheral device. The processor 501, the memory 502, and the peripheral device interface 503 may be connected through a bus or signal lines. Each peripheral device may be connected to the peripheral device interface 503 through a bus, signal lines, or a circuit board.

[0103] Those skilled in the art can understand that Figure 5 the structure shown in

[0104] The embodiments of the present disclosure also provide a non-transitory computer-readable storage medium storing computer instructions for causing a computer to execute the control method of the liquid cargo handling system described in the above embodiments. For example, the computer-readable storage medium may be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0105] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above embodiments can be completed by hardware or by a program instructing relevant hardware. The program can be stored in a computer-readable storage medium. The storage medium mentioned above can be a read-only memory, a magnetic disk, or an optical disc, etc.

[0106] In the above, there is no restriction on the present disclosure in any form. Although the present disclosure has been disclosed as above through embodiments, it is not intended to limit the present disclosure. Any person skilled in the art, without departing from the scope of the technical solution of the present disclosure, can make some changes or modifications to the above-disclosed technical content to form equivalent embodiments with equivalent changes. However, as long as it does not depart from the content of the technical solution of the present disclosure, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present disclosure still fall within the scope of the technical solution of the present disclosure.

[0107] In the above, there is no restriction on the present disclosure in any form. Although the present disclosure has been disclosed as above through embodiments, it is not intended to limit the present disclosure. Any person skilled in the art, without departing from the scope of the technical solution of the present disclosure, can make some changes or modifications to the above-disclosed technical content to form equivalent embodiments with equivalent changes. However, as long as it does not depart from the content of the technical solution of the present disclosure, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present disclosure still fall within the scope of the technical solution of the present disclosure.

Claims

1. A control method for a liquid cargo handling system, characterized in that, The control method includes: Obtaining a switching instruction for instructing to increase the unloading of the liquid cargo pump; Controlling the rotational speed of the currently operating liquid cargo pump to decrease to a first rotational speed; Controlling the rotational speed of the increased liquid cargo pump to rise to the first rotational speed. After controlling the rotational speed of the increased liquid cargo pump to rise to the first rotational speed, it includes: obtaining the first pressure and the pressure in the manifold in real time, where the first pressure is the pressure at the liquid outlet of each of the increased liquid cargo pumps; when each of the first pressures is not less than the pressure in the manifold, controlling the control valve at the liquid outlet of the increased liquid cargo pump to open; Synchronously adjusting the rotational speeds of all the liquid cargo pumps until the pressure in the manifold meets the target pressure.

2. The control method according to claim 1, characterized in that, Before obtaining the switching instruction, it further includes: Obtaining a start instruction, where the start instruction includes a first quantity, an initial rotational speed, and an initial pressure; Controlling the rotational speeds of the first quantity of liquid cargo pumps to rise until the pressures at the liquid outlets of each of the liquid cargo pumps are not less than the initial pressure, and controlling the control valves at the liquid outlets of each of the liquid cargo pumps to open.

3. The control method according to claim 2, wherein The start instruction further includes a target pressure, a speed regulation frequency, and a speed regulation amplitude. After controlling the control valves at the liquid outlets of each of the liquid cargo pumps to open, it includes: If the pressure in the manifold is not greater than the target pressure, controlling the liquid cargo pumps to increase the rotational speed according to the speed regulation frequency and the speed regulation amplitude; If the pressure in the manifold is greater than the target pressure, controlling the liquid cargo pumps to decrease the rotational speed according to the speed regulation frequency and the speed regulation amplitude.

4. The control method according to claim 3, characterized in that, The speed regulation frequency is from 5HZ to 15HZ, and the speed regulation amplitude is from 10rad / min to 30rad / min.

5. A control device for a liquid cargo handling system, characterized in that, The control device includes: A first acquisition module for obtaining a switching instruction for instructing to increase the unloading of the liquid cargo pump; A first control module for controlling the rotational speed of the currently operating liquid cargo pump to decrease to a first rotational speed; controlling the rotational speed of the increased liquid cargo pump to rise to the first rotational speed; synchronously adjusting the rotational speeds of all the liquid cargo pumps until the pressure in the manifold meets the target pressure; A second acquisition module and a second control module. After controlling the rotational speed of the increased liquid cargo pump to rise to the first rotational speed, the first acquisition module is used to obtain the first pressure and the pressure in the manifold in real time, where the first pressure is the pressure at the liquid outlet of each of the increased liquid cargo pumps; the second control module is used to control the control valve at the liquid outlet of the increased liquid cargo pump to open when each of the first pressures is not less than the pressure in the manifold.

6. The control device according to claim 5, wherein The control device further includes a third acquisition module and a third control module; before obtaining the switching instruction, the third acquisition module is used to obtain a start instruction, where the start instruction includes a first quantity, an initial rotational speed, and an initial pressure; The third control module is used to control the rotational speeds of the first quantity of liquid cargo pumps to rise until the pressures at the liquid outlets of each of the liquid cargo pumps are not less than the initial pressure, and controlling the control valves at the liquid outlets of each of the liquid cargo pumps to open.

7. The control device according to claim 6, characterized in that, The start instruction further includes a target pressure, a speed regulation frequency, and a speed regulation amplitude; the third control module includes: a first control sub-module and a second control sub-module. After controlling the control valves at the liquid outlets of the respective liquid cargo pumps to open, the first control sub-module is configured to control the liquid cargo pump to increase the rotational speed according to the speed regulation frequency and the speed regulation amplitude if the pressure in the header is not greater than the target pressure; the second control sub-module is configured to control the liquid cargo pump to decrease the rotational speed according to the speed regulation frequency and the speed regulation amplitude if the pressure in the header is greater than the target pressure.

8. The control device according to claim 7, wherein The speed regulation frequency is from 5HZ to 15HZ, and the speed regulation amplitude is from 10rad / min to 30rad / min.

Images