A Smart Control Method for Switching Between LNG and Methanol Dual Fuels in Ships

Abstract

This invention discloses an intelligent control method for dual-fuel switching of LNG and methanol in ships, relating to the field of ship fuel switching control technology. It addresses the problem that current ship fuel switching judgments rely solely on whether the ship is located in a restricted area, and lack real-time monitoring of the remaining fuel concentration in pipelines during fuel switching. The method involves: obtaining the signal type of the ship's fuel switching signal based on real-time navigation data; analyzing the ship's external environment based on the real-time navigation data, and determining whether the ship meets pipeline purging conditions based on the external environment; acquiring data on methanol usage, liquefied natural gas usage, and pipeline usage within the ship, while simultaneously controlling inert gas to purge the main input pipeline within the ship, obtaining a pipeline purging completion command; and determining whether the ship's fuel switching control is qualified based on real-time operating data. This invention simultaneously cleans the ship's fuel pipelines during the fuel switching process to ensure a high success rate for ship fuel switching.

Description

Technical Field

[0001] This invention belongs to the field of ship fuel switching control technology, specifically a smart switching control method for ship LNG and methanol dual fuels. Background Technology

[0002] A dual-fuel system for ships is a power configuration technology that allows the same main engine to flexibly switch between two types of fuel, typically liquefied natural gas (LNG) and methanol, or marine diesel or heavy fuel oil. The system integrates dual independent fuel supply lines, dedicated injectors, valves, and pretreatment devices on the engine side. Through electronic control units (ECUs) and DCS / PLC control logic, it completes a series of automated operations such as purging, preheating / precooling, injection, and ignition. Ships can achieve an optimal balance between operating costs and environmental performance while meeting strict emission control limits, taking into account fuel market price fluctuations and inventory status. Technically, it takes into account combustion efficiency, safety redundancy, and system reliability, ensuring smooth and reliable fuel switching under any sea state and speed.

[0003] In the existing technology, the determination of whether a ship needs to start a fuel switch depends only on whether the ship is in a no-emission zone, ignoring the ship's power load requirements. This leads to the problem of power fluctuations during the fuel switch. At the same time, when the ship switches fuel, the cleaning of the remaining fuel in the pipeline depends on increasing or decreasing the flow rate of inert gas. There is a lack of real-time monitoring of the concentration of the remaining fuel in the pipeline, which can easily lead to the co-burning of residual fuel and hydrate blockage.

[0004] Therefore, this invention proposes a smart switching control method for ship LNG and methanol dual fuels. Summary of the Invention

[0005] The purpose of this invention is to propose an intelligent switching control method for ship LNG and methanol dual fuels to solve the problems mentioned in the background art.

[0006] The technical problem to be solved by this invention is:

[0007] How to intelligently determine when a ship needs to switch fuel and ensure the success rate of the fuel switch.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A method for intelligent switching control of LNG and methanol dual fuels in ships, the method comprising:

[0010] Step S1: Obtain the ship's real-time navigation data and determine the signal type of the ship's fuel switching signal based on the real-time navigation data.

[0011] Step S2: Based on the ship's real-time navigation data, analyze the ship's external environment and determine whether the ship meets the pipeline purging conditions based on the external environment.

[0012] Step S3: Obtain data on methanol usage, liquefied natural gas usage, and pipeline usage within the ship; simultaneously, control inert gas to purge the main input pipeline within the ship, and receive a pipeline purging completion command.

[0013] Step S4: Obtain the ship's real-time operating data and determine whether the ship's fuel switching control is qualified based on the real-time operating data.

[0014] Furthermore, real-time navigation data includes the ship's real-time coordinates, real-time speed, and real-time heading.

[0015] Further, step S1 includes the following sub-steps:

[0016] Step S11: Obtain the port coordinates of the target port. Construct a circular area with the port coordinates as the center and the fixed port distance as the radius. Divide the circular area into a land area and a navigation area according to the coastline. Use the navigation area as the port management area of ​​the target port.

[0017] Step S12: Obtain the real-time navigation coordinates of the ship. When the real-time navigation coordinates intersect with the edge of the port management area, obtain the real-time speed of the ship and the corresponding time node.

[0018] Step S13: Take the time node when the ship intersects with the edge of the port management area as the reference time node, and then bind the ship's real-time speed with the timestamp to obtain the ship's real-time speed at all time nodes, and calculate the ship's acceleration at the current time node.

[0019] Step S14: When the ship's acceleration is less than zero and the ship's real-time heading is to enter the port management area, it is determined that the ship needs to enter the port management area, the ship's state is deceleration, and the ship's current fuel is detected.

[0020] If the ship is currently using liquefied natural gas as fuel, the type of signal the ship sends for fuel switching is a methanol switching signal;

[0021] If the ship is currently using methanol as fuel, no action will be taken.

[0022] Step S15: When the ship's acceleration is less than zero and the ship's real-time heading is out of the port management area, it is determined that the ship needs to leave the port management area, the ship's state is deceleration, and the ship's current fuel is detected.

[0023] If the ship is currently using methanol as fuel, the signal type of the fuel switching signal sent by the ship will be switching to liquefied natural gas;

[0024] If the ship is currently using liquefied natural gas as fuel, no operation will be performed;

[0025] Step S16: When the ship's acceleration is greater than or equal to zero, it is determined that the ship needs to leave the port management area, the ship's state is in an acceleration state, and the ship's current fuel is detected at the same time.

[0026] If the ship is currently using liquefied natural gas as fuel, no operation will be performed;

[0027] If the ship is currently using methanol as fuel, the type of signal the ship sends for fuel switching is a liquefied natural gas (LNG) switching signal.

[0028] Further, step S2 includes the following sub-steps:

[0029] Step S21: Obtain the ship's real-time heading, bind the ship's real-time heading with a timestamp, and then construct a heading-time node curve;

[0030] Step S22: If the signal type is a methanol switching signal, then analyze the heading-time node curve;

[0031] If the slope of any point on the heading-time node curve is greater than or equal to the slope threshold within a fixed number of time nodes, it is determined that the ship is performing a turning operation and the ship does not meet the pipeline purging conditions.

[0032] When the slope of all time points in the heading-time node curve is less than the slope threshold within a fixed number of time points, the ship is determined to meet the pipeline purging conditions and a purging start command is issued.

[0033] Step S23: If the signal type is a switching liquefied natural gas signal, then analyze the heading-time node curve;

[0034] If the slope of any point on the heading-time node curve is greater than or equal to the slope threshold within a fixed number of time nodes, the pipeline purging condition is not met.

[0035] When the slope of all time nodes in the heading-time node curve is less than the slope threshold within a fixed number of time nodes, proceed to step S24.

[0036] Step S24: Obtain the real-time speed of the vessel. If the real-time speed of the vessel is greater than or equal to the speed threshold, it is determined that the vessel does not meet the pipeline purging conditions.

[0037] If the ship's real-time speed is less than the speed threshold, the ship is deemed to meet the pipeline purging conditions, and a purging start command is issued.

[0038] Furthermore, the methanol usage data includes the methanol preheating zone and the methanol storage tank storage volume;

[0039] The data on liquefied natural gas (LNG) usage includes the preheating zone of LNG and the storage volume of LNG storage tanks;

[0040] The pipeline usage data includes the real-time fuel concentration, methanol input rate, and liquefied natural gas input rate of the main input pipeline within the ship.

[0041] Furthermore, purging the main input pipeline inside the ship involves: expelling methanol or liquefied natural gas from the main input pipeline by supplying inert gas to the main input pipeline, thereby reducing the concentration of methanol or liquefied natural gas.

[0042] The real-time fuel concentrations in the main input pipeline are: real-time concentrations of liquefied natural gas and methanol.

[0043] Further, step S3 includes the following sub-steps:

[0044] Step S31: When the ship issues a start purging command, obtain the signal type of the fuel switching signal. When the fuel switching signal is a methanol switching signal, proceed to step S32.

[0045] When the fuel switching signal is a liquefied natural gas switching signal, proceed to step S37;

[0046] Step S32: Obtain the preheating range of methanol, heat the methanol input pipeline to the maximum endpoint value corresponding to the preheating range of methanol, and then input methanol from the methanol low temperature storage device into the methanol input pipeline.

[0047] Step S33: Fix the temperature of the methanol storage tank to the standard methanol preheating temperature, obtain the storage volume of the methanol storage tank and the methanol input rate of the main input pipeline in the ship, divide the storage volume by the methanol input rate to obtain the filling time required to fill the methanol storage tank.

[0048] Step S34: Close the valve corresponding to the liquefied natural gas input pipeline. Take the time point when methanol is transported from the methanol cryogenic storage device to the methanol storage tank via the methanol input pipeline as the initial time point. Obtain the real-time concentration of liquefied natural gas in the main input pipeline at the initial time point and record it as the initial concentration of liquefied natural gas QCN.

[0049] Furthermore, step S3 also includes the following sub-steps:

[0050] Step S35: When purging the main input pipeline, obtain the standard inert gas net discharge of the intelligent manufacturing equipment industry and the pipeline volume of the main input pipeline. Then, increase the filling time upward from the initial time node and calculate the final concentration of liquefied natural gas at the corresponding time node.

[0051] Step S36: If the final concentration of liquefied natural gas is greater than or equal to the liquefied natural gas concentration threshold, it is determined that the net discharge of inert gas does not meet the standard, and the net discharge of inert gas is automatically increased until the final concentration of liquefied natural gas is less than the liquefied natural gas concentration threshold.

[0052] If the final concentration of liquefied natural gas is less than the liquefied natural gas concentration threshold, the ship issues a pipeline purging completion command.

[0053] Step S37: Obtain the preheating range and storage temperature of liquefied natural gas, as well as the storage volume of the liquefied natural gas storage tank. The steps for calculating the filling time of the liquefied natural gas storage tank are the same as those for calculating the filling time of the methanol storage tank. Similarly, the filling time of the liquefied natural gas storage tank is calculated.

[0054] Step S38, the steps for reducing the methanol concentration in the main input pipeline are the same as those for reducing the liquefied natural gas concentration in the main input pipeline. Similarly, the valves of the corresponding pipeline in the methanol input pipeline are closed, and inert gas is used for purging to make the final methanol concentration in the main input pipeline less than the methanol concentration threshold. At the same time, the ship issues a pipeline purging completion command.

[0055] Furthermore, the real-time working data specifically includes the real-time pipeline pressure and injection flow rate of the main input pipeline inside the ship, as well as the real-time combustion temperature of the engine.

[0056] Further, step S4 includes the following sub-steps:

[0057] Step S41: When the ship issues a pipeline purging completion command, the control device opens the valve corresponding to the input pipeline and inputs fuel into the engine;

[0058] Step S42: Obtain the real-time injection flow rate of the main input pipeline. If the real-time pipeline pressure of the main input pipeline is not within the pipeline pressure range, or the real-time injection flow rate is greater than the injection flow rate threshold, the ship's fuel switching control is deemed unqualified, and the control device closes the corresponding pipeline valve of the input pipeline.

[0059] If the real-time pipeline pressure of the main input pipeline is within the pipeline pressure range and the real-time injection flow rate is less than or equal to the injection flow rate threshold, then proceed to the next step.

[0060] Step S43: Obtain the real-time combustion temperature inside the engine. When the real-time combustion temperature is within the methanol combustion temperature range, the ship's fuel switching control is deemed qualified.

[0061] If the real-time combustion temperature is not within the methanol combustion temperature range, the ship's fuel switching control is deemed unqualified.

[0062] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0063] 1. This invention obtains the signal type of the ship's fuel switching signal based on real-time navigation data, and then analyzes the ship's external environment based on the real-time navigation data. Based on the external environment, it determines whether the ship meets the pipeline purging conditions. This invention determines whether the ship has the conditions for fuel switching through environmental analysis.

[0064] 2. This invention uses data on methanol usage, liquefied natural gas usage, and pipeline usage within the ship to control the purging of inert gas into the main input pipeline. Finally, it determines whether the ship's fuel switching control is qualified based on real-time operating data. This invention simultaneously cleans the ship's fuel pipelines during the fuel switching process to ensure the success rate of the ship's fuel switching. Attached Figure Description

[0065] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0066] Figure 1 This is a flowchart of the method of the present invention;

[0067] Figure 2 This is an example diagram of the port management area in this invention;

[0068] Figure 3 This is an example diagram showing the real-time heading of a vessel in this invention;

[0069] Figure 4 This is an example diagram of the storage device in this invention;

[0070] Figure 5 This is a schematic diagram of the electronic device in this invention. Detailed Implementation

[0071] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0072] Example 1: Please refer to Figures 1-4As shown, the technical solution provided by this invention is: a smart switching control method for ship LNG and methanol dual fuels, the method is as follows:

[0073] Step S1: Obtain the ship's real-time navigation data and determine the signal type of the ship's fuel switching signal based on the real-time navigation data.

[0074] Specifically, the real-time navigation data includes the ship's real-time coordinates, real-time speed, and real-time heading.

[0075] Specifically, the fuel switching signal is a signal that the ship switches fuel when it arrives at a designated position and performs a designated operation.

[0076] It should be specifically noted that the signal types are methanol switching signal and liquefied natural gas switching signal;

[0077] In this embodiment, step S1 includes the following sub-steps:

[0078] Step S11, as follows Figure 2 As shown, the port coordinates of the target port are obtained. A circular area is constructed with the port coordinates as the center and the fixed port distance as the radius. The circular area is divided into a land area and a navigation area according to the coastline. The navigation area is used as the port management area of ​​the target port.

[0079] Step S12: Obtain the real-time navigation coordinates of the ship. When the real-time navigation coordinates intersect with the edge of the port management area, obtain the real-time speed of the ship and the corresponding time node.

[0080] Step S13: The time node when the ship intersects with the edge of the port management area is used as the reference time node. Then, the ship's real-time speed is bound to the timestamp to obtain the ship's real-time speed SSHi for all time nodes, where i is the time node number, i=1,2,...,n, and n is a positive integer. The ship's acceleration a at the current time node is calculated using the following formula:

[0081] a=(SSHi-SSHi-1) / [i-(i-1)];

[0082] Specifically, when the ship's acceleration is less than zero, it is determined that the ship is decelerating; when the ship's acceleration is greater than zero, it is determined that the ship is accelerating; and when the ship's acceleration is equal to zero, it is determined that the ship is traveling at a constant speed.

[0083] In reality, the time difference between adjacent time points is one second;

[0084] Step S14: When the ship's acceleration is less than zero and the ship's real-time heading is to enter the port management area, it is determined that the ship needs to enter the port management area, the ship's state is deceleration, and the ship's current fuel is detected.

[0085] If the ship is currently using liquefied natural gas as fuel, the type of signal the ship sends for fuel switching is a methanol switching signal;

[0086] If the ship is currently using methanol as fuel, no action will be taken.

[0087] Step S15: When the ship's acceleration is less than zero and the ship's real-time heading is out of the port management area, it is determined that the ship needs to leave the port management area, the ship's state is deceleration, and the ship's current fuel is detected.

[0088] If the ship is currently using methanol as fuel, the signal type of the fuel switching signal sent by the ship will be switching to liquefied natural gas;

[0089] If the ship is currently using liquefied natural gas as fuel, no operation will be performed;

[0090] It should be specifically noted that when a ship's acceleration is less than zero and its real-time course is heading out of the port management area, the ship needs to avoid other ships within its real-time course, and therefore needs to decelerate, resulting in the ship's acceleration being less than zero.

[0091] Step S16: When the ship's acceleration is greater than or equal to zero, it is determined that the ship needs to leave the port management area, the ship's state is in an acceleration state, and the ship's current fuel is detected at the same time.

[0092] If the ship is currently using liquefied natural gas as fuel, no operation will be performed;

[0093] If the ship is currently using methanol as fuel, the type of signal the ship sends for fuel switching is a liquefied natural gas switching signal;

[0094] Specifically, the fuels for ships are liquefied natural gas (LNG) and methanol. For the same volume and the same combustion time, the heat generated by the combustion of LNG is higher than that generated by the combustion of methanol. Therefore, the power generated by the combustion of LNG is higher than that generated by the combustion of methanol.

[0095] It should be noted that when a ship enters the port management area, it must slow down and make fine adjustments to its speed and direction, thus requiring methanol as fuel; when a ship leaves the port management area, it needs to accelerate quickly or sail at a constant speed, thus requiring liquefied natural gas as fuel.

[0096] Step S2: Based on the ship's real-time navigation data, analyze the ship's external environment and determine whether the ship meets the pipeline purging conditions based on the external environment.

[0097] In this embodiment, step S2 includes the following sub-steps:

[0098] Step S21: Obtain the ship's real-time heading, bind the ship's real-time heading with a timestamp, and then construct a heading-time node curve;

[0099] Step S22: If the signal type is a methanol switching signal, then analyze the heading-time node curve;

[0100] If the slope of any point on the heading-time node curve is greater than or equal to the slope threshold within a fixed number of time nodes, it is determined that the ship is performing a turning operation and the ship does not meet the pipeline purging conditions.

[0101] When the slope of all time points in the heading-time node curve is less than the slope threshold within a fixed number of time points, the ship is determined to meet the pipeline purging conditions and a purging start command is issued.

[0102] Step S23: If the signal type is a switching liquefied natural gas signal, then analyze the heading-time node curve;

[0103] If the slope of any point on the heading-time node curve is greater than or equal to the slope threshold within a fixed number of time nodes, it is determined that the ship is performing a turning operation and does not meet the pipeline purging conditions.

[0104] When the slope of all time nodes in the heading-time node curve is less than the slope threshold within a fixed number of time nodes, proceed to step S24.

[0105] Step S24: Obtain the real-time speed of the vessel. If the real-time speed of the vessel is greater than or equal to the speed threshold, it is determined that the vessel does not meet the pipeline purging conditions.

[0106] If the ship's real-time speed is less than the speed threshold, the ship is deemed to meet the pipeline purging conditions, and a purging start command is issued.

[0107] Step S3: Obtain data on methanol usage, liquefied natural gas usage, and pipeline usage within the ship; simultaneously, control inert gas to purge the main input pipeline within the ship, and receive a pipeline purging completion command.

[0108] Specifically, the methanol usage data includes the methanol preheating zone and the methanol storage tank volume; the liquefied natural gas (LNG) usage data includes the LNG preheating zone and the LNG storage tank volume; and the pipeline usage data includes the real-time fuel concentration, methanol input rate, and LNG input rate of the main input pipeline within the ship.

[0109] Specifically, purging the main input pipeline inside the ship involves: expelling methanol or liquefied natural gas from the main input pipeline by supplying inert gas, thereby reducing the concentration of methanol or liquefied natural gas.

[0110] In practice, the preheating range for methanol is [40℃~60℃]; the real-time fuel concentration in the main input pipeline is specifically the real-time concentration of liquefied natural gas and the real-time concentration of methanol.

[0111] In this embodiment, step S3 includes the following sub-steps:

[0112] Step S31: When the ship issues a start purging command, obtain the signal type of the fuel switching signal. When the fuel switching signal is a methanol switching signal, proceed to step S32.

[0113] When the fuel switching signal is a liquefied natural gas switching signal, proceed to step S37;

[0114] Step S32, as follows Figure 4 As shown, the preheating range of methanol is obtained, the methanol input pipeline is heated to the maximum endpoint value corresponding to the preheating range of methanol, and then methanol is input from the methanol low temperature storage device to the methanol input pipeline.

[0115] In practical implementation, in the methanol low-temperature storage device, the methanol storage temperature is 20℃, and the maximum endpoint value of the methanol preheating zone is 60℃. Since the methanol storage temperature is low and the methanol boiling temperature is 65℃, the methanol input value of the storage temperature can be used to prevent the methanol from boiling due to excessively high preheating temperature.

[0116] Step S33: Fix the temperature of the methanol storage tank to the standard methanol preheating temperature, obtain the storage volume of the methanol storage tank and the methanol input rate of the main input pipeline in the ship, divide the storage volume by the methanol input rate to obtain the filling time required to fill the methanol storage tank.

[0117] The methanol input rate is measured in cubic meters per minute.

[0118] In practice, the standard methanol preheating temperature can be 50℃;

[0119] Step S34: Close the valve corresponding to the liquefied natural gas input pipeline. Take the time point when methanol is transported from the methanol cryogenic storage device to the methanol storage tank through the methanol input pipeline as the initial time point. Obtain the real-time concentration of liquefied natural gas in the main input pipeline at the initial time point and record it as the initial concentration of liquefied natural gas QCN.

[0120] Step S35: When purging the main input pipeline, obtain the standard inert gas net discharge (DPL) for the intelligent manufacturing equipment industry and the pipeline volume (GDT) of the main input pipeline. Then, add the filling time (CSC) upwards from the initial time node and calculate the final liquefied natural gas concentration (ZND) at the corresponding time node using the formula as follows:

[0121] ;

[0122] The inert gas can be nitrogen, argon, helium or neon, etc. In this embodiment, nitrogen is preferred as the inert gas because nitrogen is less expensive and easier to obtain compared with other inert gases.

[0123] Specifically, the inert gas is stored in an inert gas storage tank, which is directly connected to the main input pipeline; the inert gas storage tank is connected to a control device, which is used to change the net discharge rate of the inert gas.

[0124] Step S36: If the final concentration of liquefied natural gas is greater than or equal to the liquefied natural gas concentration threshold, it is determined that the net discharge of inert gas does not meet the standard, and the net discharge of inert gas is automatically increased until the final concentration of liquefied natural gas is less than the liquefied natural gas concentration threshold.

[0125] If the final concentration of liquefied natural gas is less than the liquefied natural gas concentration threshold, the ship issues a pipeline purging completion command.

[0126] Specifically, the liquefied natural gas concentration threshold is the concentration value at which liquefied natural gas cannot affect the combustion of methanol when liquefied natural gas is mixed with methanol;

[0127] Step S37: Obtain the preheating range and storage temperature of liquefied natural gas, as well as the storage volume of the liquefied natural gas storage tank. The steps for calculating the filling time of the liquefied natural gas storage tank are the same as those for calculating the filling time of the methanol storage tank. Similarly, the filling time of the liquefied natural gas storage tank is calculated.

[0128] Step S38, the steps for reducing the methanol concentration in the main input pipeline are the same as those for reducing the liquefied natural gas concentration in the main input pipeline. Similarly, the valves of the corresponding pipeline in the methanol input pipeline are closed, and inert gas is used for purging to make the final methanol concentration in the main input pipeline less than the methanol concentration threshold. At the same time, the ship issues a pipeline purging completion command.

[0129] Step S4: Obtain the ship's real-time operating data and determine whether the ship's fuel switching control is qualified based on the real-time operating data;

[0130] Specifically, the real-time working data includes the real-time pipeline pressure and injection flow rate of the main input pipeline inside the ship, as well as the real-time combustion temperature of the engine.

[0131] It should be noted that step S4 only analyzes the combustion status of methanol, and the analysis of liquefied natural gas is similar.

[0132] In this embodiment, step S4 includes the following sub-steps:

[0133] Step S41: When the ship issues a pipeline purging completion command, the control device opens the valve corresponding to the input pipeline and inputs fuel into the engine;

[0134] Step S42: Obtain the real-time injection flow rate of the main input pipeline. If the real-time pipeline pressure of the main input pipeline is not within the pipeline pressure range, or the real-time injection flow rate is greater than the injection flow rate threshold, the ship's fuel switching control is deemed unqualified, and the control device closes the corresponding pipeline valve of the input pipeline.

[0135] If the real-time pipeline pressure of the main input pipeline is within the pipeline pressure range and the real-time injection flow rate is less than or equal to the injection flow rate threshold, then proceed to the next step.

[0136] Step S43: Obtain the real-time combustion temperature inside the engine. When the real-time combustion temperature is within the methanol combustion temperature range, the ship's fuel switching control is deemed qualified.

[0137] When the real-time combustion temperature is not within the methanol combustion temperature range, the ship's fuel switching control is deemed unqualified.

[0138] It should be noted that the combustion temperature range for methanol is [1427℃~1627℃], and the combustion temperature range for liquefied natural gas is [1627℃~1827℃]. Therefore, if the real-time combustion temperature does not fall within the methanol combustion temperature range, the final concentration of liquefied natural gas in the main input pipeline is deemed unqualified, and the ship's fuel switching control is also deemed unqualified.

[0139] In this application, if a corresponding calculation formula appears, the above calculation formula is a dimensionless calculation. The weighting coefficient, proportional coefficient and other coefficients in the formula are set to quantify each parameter to obtain a result value. The size of the weighting coefficient and proportional coefficient is only required to not affect the proportional relationship between the parameter and the result value.

[0140] Example 2: This embodiment of the invention also provides a computer device for running the aforementioned intelligent switching control method for ship LNG-methanol dual fuel; see [link to previous example]. Figure 5 The schematic diagram of a computer device provided by the embodiment of the present invention shown above includes a memory and a processor. The memory is used to store one or more computer instructions, and the one or more computer instructions are executed by the processor to realize the above-mentioned intelligent switching control method for ship LNG methanol dual fuel.

[0141] Furthermore, Figure 5 The computer device shown also includes a communication bus and a communication interface, with the processor, communication interface, and memory connected via the communication bus;

[0142] The memory may include high-speed random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface (which can be wired or wireless), such as the Internet, wide area network, local area network, metropolitan area network, etc. The communication bus can be an ISA bus, PCI bus, or EISA bus, etc. The communication bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The symbol is represented by only one double-headed arrow, but this does not mean that there is only one communication bus or one type of communication bus.

[0143] The processor may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above methods can be completed by integrated logic circuits in the processor's hardware or by software instructions. The processor can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the method described in the foregoing embodiments.

[0144] Example 3: This embodiment of the invention also provides a computer storage medium storing computer-executable instructions. When these computer-executable instructions are called and executed by a processor, they cause the processor to implement the aforementioned intelligent switching control method for LNG and methanol dual fuels in ships. For a specific implementation, please refer to the method embodiment. The method is as follows: acquiring real-time navigation data of the ship; obtaining the signal type of the ship's fuel switching signal based on the real-time navigation data; analyzing the ship's external environment based on the real-time navigation data; determining whether the ship meets the pipeline purging conditions based on the external environment; acquiring methanol usage data, liquefied natural gas usage data, and pipeline usage data of the ship's fuels; simultaneously controlling inert gas to purge the main input pipeline within the ship; obtaining a pipeline purging completion command; acquiring real-time operating data of the ship; and determining whether the ship's fuel switching control is qualified based on the real-time operating data.

[0145] The computer program product of the intelligent switching control method for LNG and methanol dual fuels in ships provided by this invention includes a computer storage medium storing program code. The instructions included in the program code can be used to execute the methods in the preceding method embodiments. For specific implementation, please refer to the method embodiments. The method is as follows: acquire the ship's real-time navigation data, and obtain the signal type of the ship's fuel switching signal based on the real-time navigation data; analyze the ship's external environment based on the ship's real-time navigation data, and determine whether the ship meets the pipeline purging conditions based on the external environment; acquire the ship's methanol usage data, liquefied natural gas usage data, and pipeline usage data, and simultaneously control inert gas to purge the main input pipeline in the ship, and obtain a pipeline purging completion command; acquire the ship's real-time operating data, and determine whether the ship's fuel switching control is qualified based on the real-time operating data.

[0146] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and / or device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0147] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0148] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0149] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for intelligent switching control of LNG and methanol dual fuels in ships, characterized in that, The methods include: Step S1: Obtain the ship's real-time navigation data and determine the signal type of the ship's fuel switching signal based on the real-time navigation data. Step S2: Based on the ship's real-time navigation data, analyze the ship's external environment and determine whether the ship meets the pipeline purging conditions based on the external environment. Step S3: Obtain data on methanol usage, liquefied natural gas usage, and pipeline usage within the ship; simultaneously, control inert gas to purge the main input pipeline within the ship, and receive a pipeline purging completion command. Step S3 includes the following sub-steps: Step S31: When the ship issues a start purging command, obtain the signal type of the fuel switching signal. When the fuel switching signal is a methanol switching signal, proceed to step S32. When the fuel switching signal is a liquefied natural gas switching signal, proceed to step S37; Step S32: Obtain the preheating range of methanol, heat the methanol input pipeline to the maximum endpoint value corresponding to the preheating range of methanol, and then input methanol from the methanol low temperature storage device into the methanol input pipeline. Step S33: Fix the temperature of the methanol storage tank to the standard methanol preheating temperature, obtain the storage volume of the methanol storage tank and the methanol input rate of the main input pipeline in the ship, divide the storage volume by the methanol input rate to obtain the filling time required to fill the methanol storage tank. Step S34: Close the valve corresponding to the liquefied natural gas input pipeline. Take the time point when methanol is transported from the methanol cryogenic storage device to the methanol storage tank through the methanol input pipeline as the initial time point. Obtain the real-time concentration of liquefied natural gas in the main input pipeline at the initial time point and record it as the initial concentration of liquefied natural gas. Step S35: When purging the main input pipeline, obtain the standard inert gas net discharge of the intelligent manufacturing equipment industry and the pipeline volume of the main input pipeline. Then, increase the filling time upward from the initial time node and calculate the final concentration of liquefied natural gas at the corresponding time node. Step S36: If the final concentration of liquefied natural gas is greater than or equal to the liquefied natural gas concentration threshold, it is determined that the net discharge of inert gas does not meet the standard, and the net discharge of inert gas is automatically increased until the final concentration of liquefied natural gas is less than the liquefied natural gas concentration threshold. If the final concentration of liquefied natural gas is less than the liquefied natural gas concentration threshold, the ship issues a pipeline purging completion command. Step S37: Obtain the preheating range and storage temperature of liquefied natural gas, as well as the storage volume of the liquefied natural gas storage tank. The steps for calculating the filling time of the liquefied natural gas storage tank are the same as those for calculating the filling time of the methanol storage tank. Similarly, the filling time of the liquefied natural gas storage tank is calculated. Step S38, the steps for reducing the methanol concentration in the main input pipeline are the same as those for reducing the liquefied natural gas concentration in the main input pipeline. Similarly, the valves of the corresponding pipeline in the methanol input pipeline are closed, and inert gas is used for purging to make the final methanol concentration in the main input pipeline less than the methanol concentration threshold. At the same time, the ship issues a pipeline purging completion command. Step S4: Obtain the ship's real-time operating data and determine whether the ship's fuel switching control is qualified based on the real-time operating data.

2. The intelligent switching control method for ship LNG-methanol dual fuel according to claim 1, characterized in that, Real-time navigation data includes the ship's real-time coordinates, real-time speed, and real-time heading.

3. The intelligent switching control method for ship LNG-methanol dual fuel according to claim 2, characterized in that, Step S1 includes the following sub-steps: Step S11: Obtain the port coordinates of the target port. Construct a circular area with the port coordinates as the center and the fixed port distance as the radius. Divide the circular area into a land area and a navigation area according to the coastline. Use the navigation area as the port management area of ​​the target port. Step S12: Obtain the real-time navigation coordinates of the ship. When the real-time navigation coordinates intersect with the edge of the port management area, obtain the real-time speed of the ship and the corresponding time node. Step S13: Take the time node when the ship intersects with the edge of the port management area as the reference time node, and then bind the ship's real-time speed with the timestamp to obtain the ship's real-time speed at all time nodes, and calculate the ship's acceleration at the current time node. Step S14: When the ship's acceleration is less than zero and the ship's real-time heading is to enter the port management area, it is determined that the ship needs to enter the port management area, the ship's state is deceleration, and the ship's current fuel is detected. If the ship is currently using liquefied natural gas as fuel, the type of signal the ship sends for fuel switching is a methanol switching signal; If the ship is currently using methanol as fuel, no action will be taken. Step S15: When the ship's acceleration is less than zero and the ship's real-time heading is out of the port management area, it is determined that the ship needs to leave the port management area, the ship's state is deceleration, and the ship's current fuel is detected. If the ship is currently using methanol as fuel, the signal type of the fuel switching signal sent by the ship will be switching to liquefied natural gas; If the ship is currently using liquefied natural gas as fuel, no operation will be performed; Step S16: When the ship's acceleration is greater than or equal to zero, it is determined that the ship needs to leave the port management area, the ship's state is in an acceleration state, and the ship's current fuel is detected at the same time. If the ship is currently using liquefied natural gas as fuel, no operation will be performed; If the ship is currently using methanol as fuel, the type of signal the ship sends for fuel switching is a liquefied natural gas (LNG) switching signal.

4. The intelligent switching control method for ship LNG-methanol dual fuel according to claim 1, characterized in that, Step S2 includes the following sub-steps: Step S21: Obtain the ship's real-time heading, bind the ship's real-time heading with a timestamp, and then construct a heading-time node curve; Step S22: If the signal type is a methanol switching signal, then analyze the heading-time node curve; If the slope of the course-time node curve is greater than or equal to the slope threshold at any point within a fixed number of time nodes, the ship does not meet the pipeline purging conditions. When the slope of all time points in the heading-time node curve is less than the slope threshold within a fixed number of time points, the ship meets the pipeline purging conditions and issues a purging start command. Step S23: If the signal type is a switching liquefied natural gas signal, then analyze the heading-time node curve; If the slope of any point on the heading-time node curve is greater than or equal to the slope threshold within a fixed number of time nodes, the pipeline purging condition is not met. When the slope of all time nodes in the heading-time node curve is less than the slope threshold within a fixed number of time nodes, proceed to step S24. Step S24: Obtain the real-time speed of the vessel. If the real-time speed of the vessel is greater than or equal to the speed threshold, it is determined that the vessel does not meet the pipeline purging conditions. If the ship's real-time speed is less than the speed threshold, the ship is deemed to meet the pipeline purging conditions, and a purging start command is issued.

5. The intelligent switching control method for ship LNG-methanol dual fuel according to claim 4, characterized in that, The data on methanol usage includes the preheating range of methanol and the storage volume of the methanol storage tank. The data on liquefied natural gas (LNG) usage includes the preheating zone of LNG and the storage volume of LNG storage tanks; The pipeline usage data includes the real-time fuel concentration, methanol input rate, and liquefied natural gas input rate of the main input pipeline within the ship.

6. The intelligent switching control method for ship LNG-methanol dual fuel according to claim 5, characterized in that, The process of purging the main input pipeline inside the ship involves supplying inert gas into the main input pipeline to remove methanol or liquefied natural gas from the pipeline, thereby reducing the concentration of methanol or liquefied natural gas. The real-time fuel concentrations in the main input pipeline are: real-time concentrations of liquefied natural gas and methanol.

7. The intelligent switching control method for ship LNG-methanol dual fuel according to claim 1, characterized in that, The real-time operating data specifically includes the real-time pipeline pressure and injection flow rate of the main input pipeline inside the ship, as well as the real-time combustion temperature of the engine.

8. The intelligent switching control method for ship LNG-methanol dual fuel according to claim 7, characterized in that, Step S4 includes the following sub-steps: Step S41: When the ship issues a pipeline purging completion command, the control device opens the valve corresponding to the input pipeline and inputs fuel into the engine; Step S42: Obtain the real-time injection flow rate of the main input pipeline. If the real-time pipeline pressure of the main input pipeline is not within the pipeline pressure range, or the real-time injection flow rate is greater than the injection flow rate threshold, the ship's fuel switching control is deemed unqualified, and the control device closes the corresponding pipeline valve of the input pipeline. If the real-time pipeline pressure of the main input pipeline is within the pipeline pressure range and the real-time injection flow rate is less than or equal to the injection flow rate threshold, then proceed to the next step. Step S43: Obtain the real-time combustion temperature inside the engine. When the real-time combustion temperature is within the methanol combustion temperature range, the ship's fuel switching control is deemed qualified. If the real-time combustion temperature is not within the methanol combustion temperature range, the ship's fuel switching control is deemed unqualified.

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