329 results about "Marine engine" patented technology

The invention provides a marine engine turbocharger fault prediction method based on digital twinning. The marine engine turbocharger fault prediction method comprises the steps that operation parameters and vibration signals of a marine turbocharger are acquired; performing signal processing on the vibration signal; establishing a three-dimensional solid model of the supercharger; establishing a fluid excitation reconstruction model and a vibration response model according to the three-dimensional entity model; performing all-condition fault simulation based on the vibration response model to obtain fault data; constructing a full-condition fault data set and training a fault prediction model, and screening sensitive vibration characteristic parameter categories based on various vibration characteristic parameters; according to a data transmission relationship among the fluid excitation reconstruction model, the vibration response model and the fault prediction model, constructing a corresponding data twinborn model; and inputting the operation parameters and the sensitive characteristic parameters corresponding to the real-time vibration signals into a digital twinborn model, and obtaining an output fault type and a fault degree. According to the method, the fault type and degree of the supercharger are accurately predicted, and the reliability and safety of equipment are improved.

The invention relates to the field of marine engine performance monitoring and optimization, and discloses a marine engine adaptive aging prediction method and a fault diagnosis model.The prediction method comprises the following steps that a digital twin model of a marine engine is constructed, and an engine reference health state is generated; acquiring operation parameters of the marine engine in real time, and inputting the operation parameters into the digital twin model to calculate a reference performance index; identifying the degradation offset of the actuating mechanism by comparing the output of the digital twin model with the operation data of the entity engine; constructing a multi-objective optimization problem based on performance indexes of a digital twin model, and generating a Pareto optimal solution set by using an NSGA-III algorithm; and an optimal solution under a specific working condition is selected through a fuzzy comprehensive evaluation method, and degradation state evaluation and optimal control strategy generation are realized. Compared with the prior art, the method can accurately predict the degradation state of the marine engine, reduces the maintenance cost, improves the operation efficiency and reliability, and meets the dynamic optimization requirements of complex working conditions.

The invention discloses a ship engine component cross-working-condition life prediction method and system, and the method comprises the steps: collecting the operation data of key components of a ship engine in real time, and carrying out the preprocessing of the operation data of each component, so as to guarantee the data synchronism and data validity of the operation data; inputting the preprocessed operation data into the corresponding trained life prediction network model, and outputting a life prediction result corresponding to each component; the life prediction network model comprises a feature extraction module used for extracting time sequence features under different scales, splicing all the time sequence features on a feature dimension, performing feature enhancement on a splicing result based on a Transform model, and outputting a global feature vector after compression of a global average pooling layer; the life prediction module is used for outputting a life prediction result according to the global feature vector; the domain discrimination module is used for outputting a domain discrimination result according to the global feature vector; in training, the feature extraction module and the domain discrimination module carry out adversarial training.

The invention provides a ship engine gas system health assessment method and system based on digital twinning. The method comprises the steps that a gas system hierarchical structure tree is acquired; through a subjective and objective weight fusion method, carrying out importance degree evaluation on each component of the gas system; obtaining a health degree data set of components in the gas system; according to the health degree data set of the components in the gas system, combining a crown porcupine optimization algorithm to optimize a variational mode decomposition method and a sparrow algorithm to optimize a long short-term memory neural network, and predicting and obtaining the health degree of the gas system; the gas system is monitored in real time based on digital twinning, and the current health degree is displayed in real time and subsequently predicted. According to the method, the importance degree of the components of the gas system is accurately evaluated through subjective and objective weight fusion, real-time monitoring and health degree visualization are realized based on digital twinning, the health degree prediction precision is improved by adopting a double-optimization mechanism of optimization of a crown porcupine optimization algorithm and optimization of a sparrow algorithm, and efficient prediction of single input and single output is supported.

The invention discloses an intelligent optical cable marine engine room management method and system, and the method comprises the steps: collecting the operation state data of each device in a marine engine room in real time through employing an Internet of Things sensor, transmitting the operation state data to a file module in real time, and carrying out the regular calling of the data, so as to adjust the monitoring parameters of each Internet of Things sensor; performing equipment health assessment on the operation state data by adopting an economical efficiency analysis tool, a performance degradation analysis tool and an equipment operation analysis tool, and generating a health assessment report; and generating a coping strategy for abnormal data in the health assessment report based on the expert knowledge base, and matching corresponding historical events and historical maintenance methods thereof in the archive module. According to the invention, comprehensive health assessment is carried out on each device in the ship by using a multi-dimensional analysis tool, the fault prediction accuracy is improved, a coping strategy is rapidly generated in combination with an expert knowledge base and historical data, the decision-making efficiency is improved, the intelligence level of a ship cabin system is promoted, and the safety, environmental protection, economical efficiency and reliability of ship management are improved.

The invention relates to the technical field of methyl alcohol fuel injection system injectors, in particular to a high-pressure-difference methyl alcohol injector for a ship engine, which comprises a gland, an electromagnetic valve assembly, a shell, an ejector rod, a spring, a range limiting disc, a valve body, a valve core bushing, an orifice plate and a valve seat. According to the methanol injector, the fuel inlet is laterally arranged, and the overall flow direction of fuel is side-in and bottom-out, so that the leakage phenomenon possibly caused by insufficient coaxiality of external pipe joints in a conventional fuel jacking installation mode is avoided, and the sealing of an engine cannot be influenced even under severe working conditions such as continuous vibration; according to the methanol injector, methanol supply pressure (hydraulic pressure) is used for assisting in opening of the valve element of the methanol injector, compared with an injector with a conventional direct-drive electromagnetic valve opening valve element, the structure can achieve opening of the methanol injector only through smaller electromagnetic force and lower power consumption, and higher methanol injection pressure can be achieved after the spring and the supply pressure are accurately matched; and more efficient atomization can be realized.

The invention aims to provide a marine engine lubricating oil system fault diagnosis method based on multi-source domain transfer learning, and belongs to the field of engine fault diagnosis. Comprising the following steps: carrying out multi-working-condition signal acquisition and pretreatment on the marine engine lubricating oil system; constructing a multi-source domain transfer learning model; performing multi-source domain transfer learning model training and optimization to obtain a diesel engine fault diagnosis model based on multi-source domain transfer learning; and performing cross-working-condition fault diagnosis on the diesel engine to obtain a fault diagnosis result. According to the method, multi-source domain data collected under different working conditions are integrated, and deep feature extraction and fusion of the monitoring signals of the lubricating oil system of the engine are realized. According to the method, feature distribution between each source domain and the target domain is effectively aligned, and common fault features in multi-source-domain data are fully mined and utilized, so that the diagnosis model has relatively high cross-working-condition diagnosis capability while realizing fault prediction.

The invention discloses a marine engine lightweight fault diagnosis system for a variable working condition environment. The marine engine lightweight fault diagnosis system comprises a fault simulation and data acquisition module, a progressive separation module and a double-view weighted confrontation module, constructing a fault data set containing multiple working conditions through fault simulation, and dividing the fault data set into a training set with labels and a to-be-diagnosed sample set; the progressive separation module uses the training set to train a basic model, extracts to-be-diagnosed sample features to carry out joint scoring and sorting, then uses K-Means clustering and a cross-working-condition class structure matching mechanism to adaptively estimate the number of unknown fault samples, and trains a fine classifier; and the double-view weighted confrontation module fuses the output of the auxiliary domain discriminator and the fine classifier, realizes safe and accurate migration of diagnosis knowledge to a to-be-diagnosed sample set through weighted confrontation training, and obtains a final fault diagnosis model. According to the method, the fault diagnosis precision and robustness under variable working conditions and open class environments are effectively improved.

The invention relates to a test system for monitoring the temperature of a piston ring of a marine engine, which belongs to the technical field of marine engine temperature monitoring and comprises an infrared temperature measurement module arranged in a cylinder sleeve test hole, a data acquisition unit electrically connected with the infrared temperature measurement module and a data processing unit electrically connected with the data acquisition unit. The number of the cylinder sleeve test holes is multiple, the infrared temperature measurement module is used for measuring the temperature of different positions of the piston ring, measured temperature data are collected through the data collection unit and subjected to primary processing, and the data processing unit receives the data transmitted by the data collection unit and then conducts deep analysis and processing so as to obtain the temperature distribution condition of the piston ring. Real-time and accurate monitoring of the temperature of the piston ring in the operation process of the engine is facilitated, the limitation of a traditional contact type measuring method is overcome, and the damage risk of the piston ring and a cylinder sleeve is reduced.

The invention discloses a marine engine manufacturing full-process decision prediction method combined with machine learning, and relates to the technical field of marine engine manufacturing and testing. The method solves the problems of model prediction deviation, confidence coefficient imbalance, response lag and the like caused by difference between a bench test and a sea test environment in key working condition feature statistical distribution, selects an adversarial domain adaptation or confidence calibration algorithm for model training, constructs a prediction model based on a deep neural network, and improves the prediction accuracy. Through adversarial optimization or post-processing calibration of the feature extraction network, the main task prediction sub-network and the domain discrimination sub-network, the generalization ability and confidence reliability of the model are improved, the model is deployed in a sea test environment and verified in real time, and closed-loop decision control is executed based on a model prediction result by calculating an error index of a predicted value and a measured value. Through data layer alignment, model layer adaptation, verification layer verification and execution layer control, the prediction accuracy and operation safety of the marine engine in the sea test stage are remarkably improved.

The invention relates to the technical field of fire early warning, and discloses a marine engine room fire multi-sensor fusion automatic early warning system, which comprises a data analysis unit, a baseline adjustment unit, a data correction unit, an anomaly analysis unit, a cooperative calculation unit and a fire early warning unit, and is characterized in that the thermal state of an engine room is accurately reflected through a global working condition coefficient generated by the data analysis unit; a dynamic sensing datum line generated by the baseline adjustment unit can adapt to working condition changes in real time, the data correction unit eliminates interference and generates refining abnormal signals, the abnormity analysis unit generates a single-dimensional burst strength index through abnormal energy flux and other parameters to achieve accurate scoring, and the cooperative calculation unit and the fire early warning unit are matched with each other. According to the method, the fire early warning instruction is generated, the accuracy of multi-sensor cooperative fire discrimination is improved, meanwhile, the adaptability of the early warning scheme to dynamic working conditions is enhanced, and the accuracy of cabin fire monitoring is guaranteed.

A support system for outboard marine motors at the transom of a boat includes a support device having a first part that is integral with the transom and a second part that is integral with the outboard motor. The second part is translatable with respect to the first part, so that the second part moves according to an orientation in the distancing or approaching direction of the water line of the boat. A control unit is configured to set the position of the second part with respect to the first part and to generate control signals, so as to move the second part in the direction of immersion of the propeller of the outboard motor.

The invention discloses a fault inspection method and device based on turbine multi-level structure self-adaptive weighted fusion and a medium, and relates to the technical field of intelligent operation and maintenance of ships, and the method comprises the steps: constructing a multi-level physical topology monitoring structure chart and a self-adaptive weighted fusion mathematical model corresponding to a ship turbine system; acquiring monitoring data corresponding to each level; based on the first monitoring data of the first hierarchy, determining whether the first hierarchy is abnormal in operation, and based on the adaptive weighted fusion mathematical model, the second monitoring data of the second hierarchy and the third monitoring data of the third hierarchy, predicting whether the first hierarchy and / or the second hierarchy is abnormal, and obtaining a detection result, and performing fault judgment based on a detection result. The system and the method are used for solving the problems of low efficiency, low accuracy and poor effect during ship operation and maintenance in the prior art, and realizing efficient and accurate online inspection of the ship wheel system.

An end cap for guiding an exhaust gas flow of a boat engine. The end cap is configured to be attached onto a propeller nut of the boat engine. The end cap including: a base body having a bottom surface, a lateral surface and a tip, the tip and the bottom surface being spaced apart from each other in a longitudinal direction of the base body. The lateral surface extends from the bottom surface and converges in the tip. The bottom surface having a recess for receiving the propeller nut; and at least one exhaust gas-guiding structure extends helically along the lateral surface.

The utility model relates to a misfire diagnosis system for a marine gas engine, and relates to the technical field of monitoring of marine gas engines, the misfire diagnosis system comprises an engine exhaust header pressure sensor and an engine electronic control unit, the engine exhaust header pressure sensor is arranged on an exhaust pipe of the engine and is used for collecting exhaust pressure waveform data in real time, and the engine electronic control unit is used for monitoring the exhaust pressure waveform data; the engine electronic control unit receives pressure waveform data from the engine exhaust manifold pressure sensor. According to the misfire detection system for the marine fuel engine, the exhaust header pressure wave signal is selected as a signal source, engine misfire monitoring and diagnosis can be carried out, and the requirement for stable operation of the marine engine is met.

The present application belongs to the technical field of marine engine bearing bush coating, and discloses a composite treatment method for the surface of a marine heavy-duty engine bearing bush, which comprises bearing bush substrate pretreatment, electroplating treatment, electroplating post-treatment and spraying treatment. The present application breaks through the limitation of single surface treatment technology, uses a tin-nickel alloy electroplating layer as the bottom layer to provide the bearing bush with good basic strength, toughness and impact resistance, and uses a spraying layer containing solid lubricants such as molybdenum disulfide and graphite as the surface layer to endow the bearing bush with excellent compliance, embeddability and self-lubricating performance. The combination of the two perfectly solves the technical problem that the traditional process cannot simultaneously consider strength and surface performance, and is particularly suitable for the complex working conditions of frequent start-stop and power overload of marine heavy-duty engines.

A marine engine lubricating oil composition comprising: (a) at least 40% by weight of an oil of lubricating viscosity having a kinematic viscosity at 100 DEG C of from 4.0 to less than 8.0 mm2 / s; and (b) one or more polyisobutylene thickeners having a number average molecular weight of from 400 to 6,000 Daltons. The marine lubricating oil composition has a TBN of less than 70 mg KOH / g. The marine lubricating oil composition is a single-stage lubricating oil composition which meets the requirements of the SAE J300 standard revised in January 2015 on SA E 20, SAE 30, SAE 40, SAE 50 or SAE 60 single-stage lubricating oil.

The invention discloses a digital twin marine engine health assessment method, and relates to the technical field of marine engines, and the method comprises the steps: obtaining the operation data of a marine engine, and carrying out the preprocessing of the operation data of the marine engine; constructing a health index function model for reflecting the performance degradation process of the marine engine based on the preprocessed operation data of the marine engine; and collecting real-time operation data of the marine engine, and inputting the real-time operation data into the health index function model to obtain health degree evaluation data of the engine. According to the method, the health indexes capable of representing the degradation characteristics of multiple sensors of the marine engine are constructed based on the time-frequency domain characteristic parameters and kernel principal component analysis, so that the accuracy of health assessment and prediction is improved, and meanwhile, the hyper-parameters in the BiLSTM health prediction model are automatically adjusted and optimized based on the improved HHO algorithm, so that more efficient health state prediction is realized.

The utility model discloses an optical energy meter mounting bracket for a marine engine, and belongs to the technical field of diesel engines. The bracket mainly comprises a steel pipe, a small seat plate, a large seat plate, a trough plate seat plate and a rib plate, and adopts a connection mode of combining welding and bolt fixation. The steel pipe is welded on the exhaust collecting pipe to form a T-shaped foundation frame, the small seat plate is welded at the upper end of the steel pipe, the large seat plate is fixed on the small seat plate through bolts, and the length of the large seat plate can be adjusted to adapt to installation of different numbers of optical energy meters. The groove plate base plate is welded to the side face of the steel pipe and used for standardizing cable wiring. The rib plate is welded to the bottom of the large base plate to enhance structural strength. The solar energy meter support solves the problems that a traditional solar energy meter support is inflexible in installation and inconvenient to maintain, has the advantages of being simple in structure, convenient to install, high in adjustability and the like, can effectively improve reliability and attractiveness of installation of a solar energy meter, and is suitable for temperature monitoring systems of various marine diesel engines.

LUBRICANT COMPOSITION FOR 4-STROKE MARINE ENGINE The present invention relates to a lubricating composition for a 4-stroke marine engine, comprising: - one or more base oils, of which at least 5% to 95% by mass, relative to the total mass of said lubricating composition, are one or more base oils chosen from Group II oils, Group III oils and their mixtures; - 0.3% to 3%, in particular 0.5% to 2%, by mass of a styrene-diene(s) hydrogenated copolymer, relative to the total mass of said lubricating composition, and - 2% to 30% by mass of detergent(s), relative to the total mass of said lubricating composition, said lubricating composition being free of olefin copolymer, and wherein the kinematic viscosity at 100°C, measured according to ASTM D445, of the base oil or base oil mixture is strictly less than 7 mm² / s. Figure for the abstract: none

An adaptable tie bar assembly for use with a power boat having more than one engine. The adaptable tie bar assembly comprises a hollow tube for a first part, a rod for second part that slides within the first part of the adaptable tie bar assembly and a pin to secure the rod second part in fixed position in the hollow tube at which point the engines are parallel and the power boat is being operated at higher speeds. A solenoid may be used to insert and retract the pin. Physically aligned and secured engines improve safety when moving at high speeds. At lower speeds, being able to operate the engines independently enables better steering control.

The present application relates to the technical field of bearing shell positioning, in particular to a hole system bidirectional positioning tool and method for bearing shell of marine engine. It comprises a positioning plate and a tool base, the positioning plate is fixed with the bearing shell through positioning pins, and a V-shaped groove is opened on the lower surface, and the tool base is provided with load-bearing ball plunger and positioning ball plunger. The positioning method comprises: fixing the positioning plate on the bottom of the bearing shell by the robot and hoisting it to the tool base; releasing the locking of the positioning ball plunger, so that it pops out; after positioning is completed, the load-bearing ball plunger is controlled to descend, the load is transferred to the tool base, and the positioning ball plunger is relocked. The present application is adapted to the lightweight structure of the bearing shell, and the positioning efficiency and accuracy are improved through bidirectional step positioning combined with the robot, the processing quality is guaranteed, and the operation difficulty is reduced.

The invention discloses a marine methanol dual-fuel engine tail gas wet-type treatment device in the technical field of marine engines, and the marine methanol dual-fuel engine tail gas wet-type treatment device comprises an annular conveying assembly installed on the broadside of a ship, a plurality of treatment assemblies are arranged on the annular conveying assembly, and the annular conveying assembly is used for driving all the treatment assemblies to be immersed in and separated from seawater periodically; the treatment assembly comprises a cylinder, the interior of the cylinder is divided into a seawater washing area and a catalytic oxidation area through a partition plate, a stirrer is arranged in the seawater washing area, and a fluid power conversion device used for driving the stirrer through water flow is arranged at the end of the cylinder. And a catalysis module, an activated carbon module and a negative pressure pump are sequentially arranged in the catalytic oxidation region from the airflow conveying direction. According to the device, circulating operation of multiple treatment assemblies is achieved through the annular conveying assembly, continuous tail gas treatment is achieved, breakdown of the whole system caused by failure of a single treatment assembly is avoided, seawater is used as a washing medium, and low-cost and efficient tail gas treatment is achieved.

The application relates to the technical field of air flow treatment equipment, and particularly discloses an air flow treatment device for a ship engine room, which comprises a first muffler, a second muffler, a column body, a first heat exchange assembly and a second heat exchange assembly, and a heat exchange pipe. The second muffler is arranged in the first muffler along the axial direction of the first muffler; the column body is arranged in the second muffler along the axial direction of the second muffler; the first heat exchange assembly is arranged between the first muffler and the second muffler; the second heat exchange assembly is arranged between the second muffler and the column body; the heat exchange pipe has a heat exchange medium inside; the outer wall of the heat exchange pipe is in abutment with the first heat exchange assembly and the second heat exchange assembly; the heat exchange pipe is used for heat exchange with the first heat exchange assembly and the second heat exchange assembly; the two ends of the heat exchange pipe are respectively provided with an inlet end and an outlet end; and the inlet end and the outlet end extend out of the outer wall of the first muffler. The device can adjust the temperature of the air flow input into the engine room, and meets the requirement of the air temperature of the ship engine room.

A kind of marine low-pressure selective catalytic reduction denitration system regeneration method utilizes marine engine supercharger front high-temperature exhaust waste heat, to heat up to ammonium bisulfate decomposition temperature point to SCR system, to realize the regeneration of SCR system.Supercharger front high-temperature exhaust gas is introduced into SCR reactor by exhaust gas bypass valve, and the flow of high-temperature exhaust gas can be changed by adjusting the opening of exhaust gas bypass valve according to the volume of catalyst in SCR reactor and the set regeneration temperature.The invention can save the traditional engine external afterburner, significantly reduce the floor area of SCR system, simplify the operation of SCR system, and realize the full utilization of engine exhaust waste heat utilization.

To provide a treatment system for ammonia combustion exhaust gas capable of achieving both reduction of slip NH3 and suppression of by-production of N2O.SOLUTION: An ammonia combustion exhaust gas treatment system for treating a combustion exhaust gas of a marine engine using ammonia as a main fuel in which an SCR catalytic converter 3 for treating NOx in the combustion exhaust gas is disposed, a NH3 for treating a slip ASC5 is disposed on a downstream side of the SCR catalytic converter 3, and a ratio of a volume of the SCR catalytic converter 3 in contact with the exhaust gas to a volume of the NH3 is adjusted so that a NH3 concentration after the slip NH3 treatment and a N2O concentration generated during the slip ASC5 treatment are equal to or less than a predetermined concentration.SELECTED DRAWING: Figure 1

The invention provides an optimization method and system for a marine engine room ventilation system, and relates to the technical field of analogue simulation, and the method comprises the steps: constructing a ventilation system simulation model of a marine engine room; according to the structure information and the working condition information of the ventilation system simulation model, determining the total heat dissipating capacity of the equipment; determining a reference ventilation quantity and a ventilation quantity area distribution table according to the total heat dissipation quantity of the equipment; setting the reference ventilation quantity and the ventilation quantity area distribution table into a ventilation system simulation model; performing fluid dynamic simulation on the ventilation system simulation model to generate a problem list; the optimal ventilation system structure parameters are optimized and determined through a swarm intelligence algorithm by taking weakening of hot spots, reduction of dead corner volume fraction reduction and weakening of a backflow path as targets. Hot spot areas in the cabin can be effectively weakened, the volume fraction of ventilation dead corners is reduced, the short-circuit backflow phenomenon is weakened, and the overall energy efficiency and design reliability of a ventilation system are remarkably improved while safe operation of equipment is guaranteed.

The invention relates to the technical field of engine manufacturing, in particular to a marine engine rack assembling and welding method and an auxiliary tool. The method comprises the following steps: sequentially standing and assembling web plates on a bottom plate of a rack and fixing by spot welding; mounting an auxiliary tool; the two ends of an adjusting rod are fixed to the two adjacent web plates correspondingly, and the top span size and perpendicularity of the web plates are sequentially adjusted through the adjusting rod; the side plates and the top plate of the rack are sequentially assembled, and the sizes among the web, the side plates and the top plate are adjusted and fixed through positioned welding; and the adjusting rod and the auxiliary tool are detached, and the auxiliary tool is taken out from the side face hole of the rack. The problems that in the prior art, potential safety hazards of climbing operation are large, the position and size of a web are difficult to adjust, and the production efficiency is low due to the fact that tools are inconvenient to remove are solved, and therefore safe, efficient and accurate rack assembling and welding are achieved.

The application discloses a nano-structure thermal protection coating for hydrogen fuel gas turbine and a preparation method thereof. The nano-structure thermal protection coating takes high-temperature alloy as a substrate, and sequentially deposits a bonding bottom layer, a yttrium stabilized zirconium oxide or zirconate intermediate layer and a silicate top layer on the surface of the substrate. The application starts from the design of the coating structure, and aims at the problems of low service temperature and poor water-oxygen corrosion resistance of the existing thermal protection coating for gas turbine. The water-oxygen corrosion resistance function of the silicate material is superimposed on the thermal protection coating for gas turbine, and the coating structure is optimized to form a new thermal protection coating structure resistant to high-temperature corrosion. The new thermal protection coating structure can not only meet more extreme service environments, but also resist water-oxygen corrosion at high temperature. The new thermal protection coating structure is suitable for hydrogen fuel power generation gas turbine, and is also suitable for hydrogen fuel or hydrogen mixed marine engines, hydrogen fuel rocket engines and other hydrogen fuel gas turbines.

The utility model relates to an external cylinder cover air inlet channel methanol injection switching system, and relates to the field of ship engineering and power systems. The methanol spraying device comprises a cylinder cover, a front-end switching block arranged at one end of the top of the cylinder cover, a methanol spraying device penetrating through the front-end switching block, a middle-end switching block arranged at the top of the methanol spraying device and connected with the front-end switching block, a rear-end switching block arranged on the middle-end switching block, a methanol distribution block arranged on the rear-end switching block and a methanol double-wall pipe arranged on the methanol distribution block. The alcohol spraying device is obliquely arranged above the air inlet channel and follows the air inlet direction, so that the spraying resistance is reduced; the methanol double-wall pipe is connected to the two transverse sides of the methanol distribution block, and methanol is supplied to the methanol sprayer through the middle-end adapter block and the rear-end adapter block. The external connection type design is adopted, large-scale transformation of an existing engine structure is not needed, the transformation cost and the implementation difficulty are reduced, and the engine is suitable for various types of ship engines.