A pure methanol power system and a ship

Abstract

The application discloses a pure methanol power system and a ship, the power system comprises a methanol fuel storage unit, a methanol supply unit, a pure methanol fuel engine, a generator, a main distribution board and a propulsion branch, the power system takes pure methanol as the only combustion fuel, and a complete system-level power architecture is formed from fuel storage, fuel supply, engine power generation, power distribution to ship propulsion, no diesel or other fossil fuels are involved, no sulfur oxide and fossil source particulate matter emissions are generated in engine exhaust, the number of system component parts is greatly reduced, pipeline layout is significantly simplified, there is no switching process between the methanol mode and the diesel mode in the dual-fuel system, problems such as combustion instability, emission transient deterioration and methanol replacement rate reduction under low load in the fuel switching working condition are eliminated, parameters such as injection timing, injection pressure and air-fuel ratio do not need to be adjusted according to fuel mode switching, and the complexity and failure risk of the control system are significantly reduced.

Description

Technical Field

[0001] This application relates to the field of marine power system technology, and in particular to a pure methanol power system and a ship. Background Technology

[0002] With the goal of net-zero emissions for ship systems, traditional ship propulsion systems that use heavy oil or diesel as a single fuel can no longer meet increasingly stringent emission compliance requirements. The current mainstream technology route for methanol-powered ships is the methanol-diesel dual-fuel engine solution, which requires the use of a small amount of diesel for ignition to solve the problem of methanol's low cetane number and difficulty in compression ignition, and cannot completely get rid of dependence on fossil fuels.

[0003] Existing dual-fuel propulsion systems have significant drawbacks. These systems require separate fuel storage and supply units for both methanol and diesel, resulting in complex system architecture, large cargo space requirements, and high maintenance costs. Diesel ignition is always involved in combustion, leading to emissions that fail to meet requirements. Fuel switching conditions also present problems such as unstable combustion, power fluctuations, and emission degradation at low loads. Current technologies primarily focus on improving the combustion technology of the engine itself, lacking a complete system-level design solution for pure methanol single-fuel vessels, encompassing fuel storage and supply, engine power generation, power distribution, propulsion, and overall shipboard electrical systems. Summary of the Invention

[0004] In view of the deficiencies in the prior art, this application provides a pure methanol power system and a ship to solve the problems of poor power switching reliability and failure to meet emission requirements in the prior art ship power system.

[0005] The above-mentioned objectives of this application are mainly achieved through the following technical solutions: A pure methanol power system, the power system comprising: Methanol fuel storage unit, used to store methanol fuel; A methanol supply unit is connected to the methanol fuel storage unit and is used to output methanol fuel from the methanol fuel storage unit; A pure methanol fuel engine is connected to the methanol supply unit, and the pure methanol fuel engine uses methanol fuel as fuel. A generator is connected to the pure methanol fuel engine, and the pure methanol fuel engine drives the generator to generate electrical energy. The pure methanol fuel engine and the generator form a pure methanol fuel generator set. The main distribution board, electrically connected to the generator, is used to receive and distribute the electrical energy generated by the generator; The propulsion branch is electrically connected to the main power distribution board. The propulsion branch includes a propulsion motor, a gearbox, a shaft system, and a propeller connected in sequence. The propulsion branch is used to convert electrical energy into ship propulsion power.

[0006] In an optional implementation, the power system further includes an equipment power supply branch, which is electrically connected to the main switchboard and is used to provide electrical energy to the ship's machinery and equipment.

[0007] In an optional embodiment, the power system further includes a domestic power supply branch electrically connected to the main switchboard. The domestic power supply branch includes a transformer and a low-voltage switchboard connected in sequence and is used to provide power to the ship's living facilities and electrical equipment.

[0008] In an optional embodiment, at least two sets of pure methanol fuel generator sets are provided, and at least two sets of pure methanol fuel generator sets are connected in parallel to the main distribution board, and at least two sets of pure methanol fuel generator sets serve as backups for each other.

[0009] In an optional embodiment, the methanol fuel storage unit is a methanol fuel tank or a methanol fuel storage tank, and the methanol supply unit includes a methanol delivery pump and a methanol delivery pipeline. The inlet end of the methanol delivery pump is connected to the methanol fuel storage unit, and the outlet end of the methanol delivery pump is connected to the fuel inlet of the pure methanol fuel engine through the methanol delivery pipeline.

[0010] In an optional embodiment, the methanol supply unit further includes a methanol preheating device, which is installed on the methanol delivery pipeline and is used to heat the methanol fuel to a preset temperature range.

[0011] In an optional embodiment, the inner wall of the methanol fuel storage unit is provided with an anti-corrosion layer, which is a coating or lining resistant to methanol corrosion, and the material of the anti-corrosion layer is selected from at least one of epoxy resin coating, polytetrafluoroethylene lining or stainless steel composite plate.

[0012] In an optional embodiment, the inner wall of the methanol fuel storage unit is further provided with a methanol leakage detection device, which includes a liquid level sensor located at the bottom of the methanol fuel storage unit. When the liquid level sensor detects a liquid level drop rate exceeding a preset threshold, a leakage alarm signal is triggered.

[0013] In an optional embodiment, the methanol leak detection device further includes a methanol vapor concentration sensor disposed around the methanol fuel storage unit. When the methanol vapor concentration detected by the methanol vapor concentration sensor exceeds a preset safe concentration, a leak alarm signal is triggered.

[0014] Based on the same inventive concept, this application also provides a ship, which includes the power system as described above.

[0015] Compared with the prior art, the advantages of this application are: The pure methanol power system of this application includes a methanol fuel storage unit, a methanol supply unit, a pure methanol fuel engine, a generator, a main switchboard, and a propulsion branch. The methanol fuel storage unit is used to store methanol fuel; the methanol supply unit is connected to the methanol fuel storage unit and is used to output the methanol fuel from the methanol fuel storage unit; the pure methanol fuel engine is connected to the methanol supply unit and uses methanol fuel as fuel; the generator is connected to the pure methanol fuel engine and drives the generator to generate electrical energy, and the pure methanol fuel engine and the generator form a pure methanol fuel generator set; the main switchboard is electrically connected to the generator and is used to receive and distribute the electrical energy generated by the generator. The propulsion branch is electrically connected to the main power distribution board. The propulsion branch includes a propulsion motor, a gearbox, a shaft system, and a propeller connected in sequence. The propulsion branch is used to convert electrical energy into ship propulsion power.

[0016] This power system uses pure methanol as the sole combustion fuel, forming a complete system-level power architecture from fuel storage, fuel supply, engine power generation, power distribution to ship propulsion, fundamentally solving the problem of dependence on fossil fuels in existing methanol and diesel dual-fuel power systems.

[0017] Pure methanol in the methanol fuel storage unit is supplied to the pure methanol fuel engine via the methanol supply unit. The engine injects methanol into the cylinder via direct injection, and complete combustion of methanol is achieved through spark plug ignition or high compression ratio compression ignition, converting chemical energy into mechanical energy, which in turn drives a coaxially connected generator to generate electricity. Since no diesel or other fossil fuels are involved in the entire combustion process, no sulfur oxides or fossil particulate matter are emitted in the engine exhaust, eliminating the emission residue problems caused by diesel ignition in dual-fuel systems from the fuel source.

[0018] Compared to the complex architecture of traditional dual-fuel power systems, which require simultaneous configuration of methanol and diesel fuel tanks, two independent supply pipelines, and a dual-fuel switching control system, this power system only needs one methanol fuel storage unit and one methanol supply unit. It eliminates the diesel storage tank, diesel supply pipelines, ignition injection system, and fuel mode switching control logic, significantly reducing the number of system components and simplifying the pipeline layout. The reduced construction costs, smaller tank occupancy, and decreased daily maintenance workload effectively solve the practical engineering problems of existing dual-fuel systems, such as high maintenance frequency and difficult troubleshooting due to their complex architecture.

[0019] This propulsion system centrally receives and distributes electrical energy through a main switchboard. The propulsion motor in the propulsion branch receives the electrical energy output from the main switchboard and converts it into rotational mechanical energy. This energy is then matched for speed and amplified by a gearbox before being transmitted to the propeller via the shaft system. Ultimately, the rotational mechanical energy is converted into water thrust to propel the ship forward. This achieves physical decoupling between the engine and propeller, allowing the engine to operate stably at its optimal speed and load point, eliminating the need for frequent adjustments to operating conditions based on propeller speed changes, as is common in traditional direct-drive systems. Furthermore, the propulsion motor's speed can be infinitely adjusted by regulating the input electrical power. Ship speed regulation no longer depends on engine speed changes but can be achieved through electrical control, resulting in more flexible and stable handling response. This avoids power fluctuations and combustion instability that can occur in dual-fuel systems during fuel switching or sudden load changes.

[0020] In this power system, the pure methanol fuel engine always operates on a single fuel, eliminating the switching process between methanol and diesel modes inherent in dual-fuel systems. This eliminates problems such as unstable combustion, transient emission deterioration, and decreased methanol substitution rate under low load conditions during fuel switching. The engine maintains stable combustion of pure methanol across the entire load range, with a single and deterministic combustion control strategy. It eliminates the need to adjust multiple control parameters such as injection timing, injection pressure, and air-fuel ratio based on fuel mode switching, significantly reducing the complexity and failure risk of the control system. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of the power system provided in the embodiments of this application; In the diagram: 1. Methanol fuel storage unit; 2. Methanol supply unit; 3. Pure methanol fuel engine; 4. Generator; 5. Main switchboard; 600. Propulsion branch; 601. Propulsion motor; 602. Gearbox; 603. Shaft system; 604. Propeller; 700. Equipment power supply branch; 800. Domestic power supply branch; 801. Transformer; 802. Low-voltage switchboard. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that the description of these embodiments is intended to aid in understanding the invention, but does not constitute a limitation thereof. The specific structural and functional details disclosed herein are merely for describing exemplary embodiments of the invention. However, the invention can be embodied in many alternative forms and should not be construed as being limited to the embodiments described herein.

[0024] like Figure 1 As shown, Figure 1 A schematic diagram of a power system provided in this application embodiment; a pure methanol power system, the power system including a methanol fuel storage unit 1, a methanol supply unit 2, a pure methanol fuel engine 3, a generator 4, a main switchboard 5, and a propulsion branch 600, wherein: like Figure 1 As shown, the methanol fuel storage unit 1 is used to store methanol fuel, providing a fuel source for the entire power system. The methanol fuel storage unit 1 includes a methanol fuel tank, which is located inside the ship's hull. The volume of the methanol fuel tank is designed according to the ship's range requirements and the energy density of methanol fuel to meet the fuel storage requirements for the ship to complete the entire voyage without refueling en route.

[0025] The methanol fuel tank is equipped with a venting device at the top, which is used to balance the air pressure inside the tank and discharge methanol vapor. The outlet end of the venting device is connected to a methanol vapor recovery pipeline or leads to a safe area for discharge to prevent methanol vapor from accumulating in the confined space and forming an explosive gas mixture. The bottom of the methanol fuel tank is equipped with a fuel outlet, which is connected to the methanol supply unit 2 through a pipeline.

[0026] like Figure 1 As shown, the methanol supply unit 2 is connected to the methanol fuel storage unit 1 and is used to output the methanol fuel in the methanol fuel storage unit 1; the methanol supply unit 2 outputs the methanol fuel in the methanol fuel storage unit 1 to the pure methanol fuel engine 3. The methanol supply unit 2 continuously and stably supplies methanol fuel to the pure methanol fuel engine 3, ensuring that the engine can obtain sufficient fuel supply under various operating conditions.

[0027] A pure methanol fuel engine 3 is connected to the methanol supply unit 2, and the pure methanol fuel engine 3 uses methanol fuel as fuel. The pure methanol fuel engine 3 receives methanol fuel supplied by the methanol supply unit 2 and injects the methanol fuel into the cylinder at high pressure through direct injection. The methanol fuel mixes thoroughly with the high-temperature and high-pressure air drawn in through the intake system and compressed, forming a combustible mixture. Because methanol has a low cetane number and is difficult to ignite spontaneously through compression ignition, the pure methanol fuel engine 3 generates an electric spark at the end of the compression stroke to ignite the methanol-air mixture in the cylinder. After ignition, the mixture burns and expands rapidly, generating high-temperature and high-pressure gas that pushes the piston downward, converting the chemical energy released by the combustion of methanol into the reciprocating linear motion mechanical energy of the piston. The piston is connected to the crankshaft through a connecting rod. According to the kinematic principle of the crank-connecting rod mechanism, the reciprocating linear motion of the piston is transmitted to the crankshaft through the connecting rod, converting it into continuous rotational motion of the crankshaft, thereby outputting rotational mechanical energy at the output end of the crankshaft. The pure methanol fuel engine 3 operates solely on methanol, with no diesel or other fossil fuels involved in the entire combustion process, thus eliminating sulfur oxides and fossil particulate matter emissions from fossil fuel combustion at the fuel source.

[0028] like Figure 1 As shown, generator 4 is connected to pure methanol fuel engine 3, and pure methanol fuel engine 3 drives generator 4 to generate electrical energy. Pure methanol fuel engine 3 and generator 4 form a pure methanol fuel generator 4 group. The input shaft of the generator 4 is coaxially connected to the crankshaft output end of the pure methanol fuel engine 3 via a coupling. When the crankshaft of the pure methanol fuel engine 3 rotates, it directly drives the rotor of the generator 4 to rotate synchronously through the coupling. During the rotation of the rotor of the generator 4, the excitation winding on it generates a rotating magnetic field. This rotating magnetic field moves relative to the stator winding. According to the principle of electromagnetic induction, the conductors in the stator winding cut the magnetic lines of force of the rotating magnetic field, inducing an alternating electromotive force in the stator winding, thereby converting the rotational mechanical energy output by the pure methanol fuel engine 3 into electrical energy. The pure methanol fuel generator 4 integrates the two energy conversions from chemical energy to mechanical energy and then to electrical energy into one unit, providing a basis for the centralized distribution and flexible use of electrical energy on the main distribution board 5.

[0029] like Figure 1As shown, the main distribution board 5 is electrically connected to the generator 4 and is used to receive and distribute the electrical energy generated by the generator 4. The main distribution board 5 is the power distribution hub of the power system. The input end of the main distribution board 5 is connected to the output end of the generator 4 via a power cable, and the electrical energy generated by the generator 4 is transmitted to the main distribution board 5 via the power cable. The main distribution board 5 is equipped with a busbar and electrical components such as circuit breakers, disconnect switches, and protective relays connected to the busbar. After the electrical energy generated by the generator 4 flows into the busbar, the circuit breakers control the on / off state of each output branch, distributing the electrical energy to each power consumption branch according to a preset distribution path. The main distribution board 5 centrally receives and uniformly distributes electrical energy, enabling each power consumption branch to obtain electrical energy from the same power source, thus realizing centralized management and orderly distribution of the ship's electrical energy.

[0030] like Figure 1 As shown, the propulsion branch 600 is electrically connected to the main power distribution board 5. The propulsion branch 600 includes a propulsion motor 601, a gearbox 602, a shaft system 603, and a propeller 604 connected in sequence. The propulsion branch 600 is used to convert electrical energy into ship propulsion power.

[0031] The propulsion motor 601 is connected to the output end of the main power distribution board 5 via a power cable, and the main power distribution board 5 supplies electrical energy to the propulsion motor 601. After receiving electrical energy, the stator winding of the propulsion motor 601 is energized to generate a rotating magnetic field. The rotating magnetic field drives the rotor to rotate, converting the electrical energy into rotational mechanical energy of the output shaft of the propulsion motor 601 according to the principle of electromagnetic force. The output shaft of the propulsion motor 601 is connected to the input shaft of the gearbox 602. The gearbox 602 is equipped with multi-stage meshing gear pairs. According to the kinematic principle of gear transmission, the gearbox 602 converts the high-speed, low-torque rotational mechanical energy output by the propulsion motor 601 into low-speed, high-torque rotational mechanical energy to match the working requirement of the propeller 604 to generate sufficient thrust at a lower speed. The output shaft of the gearbox 602 is connected to the shaft system 603, which extends longitudinally along the ship and transmits the rotational mechanical energy output by the gearbox 602 to the stern. The propeller 604 is mounted at the end of the shaft system 603. Driven by the shaft system 603, the blades of the propeller 604 rotate, exerting a backward force on the surrounding water. The water exerts an equal and opposite reaction force on the blades; the component of this reaction force along the ship's forward direction is the ship's propulsion force, propelling the ship forward in the water. The propulsion branch 600, through the sequential connection of the propulsion motor 601, gearbox 602, shaft system 603, and propeller 604, completes a step-by-step transformation process from electrical energy to rotational mechanical energy, from rotational mechanical energy to speed-torque matching, from speed-torque matching to power transmission, and from power transmission to ship propulsion force, ultimately achieving the ship's propulsion and navigation.

[0032] like Figure 1 As shown, in an optional embodiment, the pure methanol power system of this application includes a methanol fuel storage unit 1, a methanol supply unit 2, a pure methanol fuel engine 3, a generator 4, a main switchboard 5, and a propulsion branch 600. The methanol fuel storage unit 1 is used to store methanol fuel; the methanol supply unit 2 is connected to the methanol fuel storage unit 1 and is used to output the methanol fuel in the methanol fuel storage unit 1; the pure methanol fuel engine 3 is connected to the methanol supply unit 2 and uses methanol fuel as fuel; the generator 4 is connected to the pure methanol fuel engine 3, and the pure methanol fuel engine 3 drives the generator 4 to generate electrical energy, and the pure methanol fuel engine 3 and the generator 4 form a pure methanol fuel generator 4 group; the main switchboard 5 is electrically connected to the generator 4 and is used to receive and distribute the electrical energy generated by the generator 4. The propulsion branch 600 is electrically connected to the main power distribution board 5. The propulsion branch 600 includes a propulsion motor 601, a gearbox 602, a shaft system 603, and a propeller 604 connected in sequence. The propulsion branch 600 is used to convert electrical energy into ship propulsion power.

[0033] This power system uses pure methanol as the sole combustion fuel, forming a complete system-level power architecture from fuel storage, fuel supply, engine power generation, power distribution to ship propulsion, fundamentally solving the problem of dependence on fossil fuels in existing methanol and diesel dual-fuel power systems.

[0034] Pure methanol in methanol fuel storage unit 1 is supplied to pure methanol fuel engine 3 via methanol supply unit 2. The engine injects methanol into the cylinder via direct injection, and complete combustion of methanol is achieved through spark plug ignition or high compression ratio compression ignition, converting chemical energy into mechanical energy, which in turn drives the coaxially connected generator 4 to rotate and generate electricity. Since no diesel or other fossil fuels are involved in the entire combustion process, no sulfur oxides or fossil particulate matter are emitted in the engine exhaust, eliminating the emission residue problems caused by diesel ignition in dual-fuel systems from the fuel source.

[0035] like Figure 1 As shown, compared to the complex architecture of traditional dual-fuel power systems that require simultaneous configuration of methanol fuel tanks, diesel fuel tanks, two independent supply pipelines, and a dual-fuel switching control system, this power system only requires one methanol fuel storage unit 1 and one methanol supply unit 2. It eliminates the diesel storage tank, diesel supply pipelines, ignition injection system, and fuel mode switching control logic, significantly reducing the number of system components and greatly simplifying the pipeline layout. The reduced construction costs, decreased tank space occupancy, and reduced daily maintenance workload effectively solve the practical engineering problems of existing dual-fuel systems, such as high maintenance frequency and difficult troubleshooting due to their complex architecture.

[0036] This power system centrally receives and distributes electrical energy through the main switchboard 5. The propulsion motor 601 in the propulsion branch 600 receives the electrical energy output from the main switchboard 5 and converts it into rotational mechanical energy. This energy is then matched for speed and amplified by the gearbox 602, and transmitted to the propeller 604 via the shaft system 603. Ultimately, the rotational mechanical energy is converted into water thrust to propel the ship forward. This achieves physical decoupling between the engine and the propeller 604, allowing the engine to operate stably at its optimal speed and load point, eliminating the need for frequent adjustments to operating conditions as required by traditional direct-drive mechanical systems. Furthermore, the speed of the propulsion motor 601 can be infinitely regulated by adjusting the input electrical power. Ship speed adjustment no longer depends on engine speed changes but can be achieved through electrical control, resulting in more flexible and stable handling response and avoiding power fluctuations and combustion instability that occur during fuel switching or sudden load changes in dual-fuel systems.

[0037] In this power system, the pure methanol fuel engine 3 always operates on a single fuel, eliminating the switching process between methanol and diesel modes inherent in dual-fuel systems. This eliminates problems such as unstable combustion, transient emission deterioration, and decreased methanol substitution rate under low load conditions during fuel switching. The engine maintains stable combustion of pure methanol across the entire load range, with a single and deterministic combustion control strategy. It eliminates the need to adjust multiple control parameters such as injection timing, injection pressure, and air-fuel ratio based on fuel mode switching, significantly reducing the complexity and failure risk of the control system.

[0038] In an optional embodiment, the power system further includes an equipment power supply branch 700, which is electrically connected to the main power distribution board 5 and is used to provide power to the ship's mechanical equipment.

[0039] During navigation and berthing operations, in addition to the propulsion system, a large number of mechanical devices, including but not limited to steering gear, anchor winches, mooring winches, bilge pumps, ballast pumps, fire pumps, ventilators, refrigeration compressors, and various hydraulic power units, require a stable power supply to their drive motors. The equipment power supply branch 700 has an independent output circuit drawn from the main distribution board 5, delivering power to the drive motors of each mechanical device via dedicated power cables, ensuring that each device receives power matching its rated power and voltage level. The equipment power supply branch 700 and the propulsion branch 600 belong to different output circuits on the main distribution board 5 and are electrically independent. When the propulsion branch 600 experiences current fluctuations due to sudden load changes in the propulsion motor 601, the voltage and frequency on the equipment power supply branch 700 remain unaffected. This ensures the power supply stability and responsiveness of critical mechanical devices such as steering gear and anchor winches during ship maneuvering, preventing malfunctions or shutdowns caused by propulsion load fluctuations, thereby guaranteeing navigation and operational safety.

[0040] like Figure 1 As shown, in an optional embodiment, the power system further includes a domestic power supply branch 800 electrically connected to the main switchboard 5. The domestic power supply branch 800 includes a transformer 801 and a low-voltage switchboard 802 connected in sequence, and is used to provide power to the ship's living facilities and electrical equipment.

[0041] The main distribution board 5 outputs electrical energy at the ship's power-grade voltage, typically 690V or higher AC. This voltage level is suitable for driving the propulsion motor 601 and high-power mechanical equipment. However, for lighting fixtures, kitchen appliances, air conditioning terminals, entertainment equipment, communication terminals, and various small electrical devices in the ship's living areas, the power-grade voltage is too high, posing a risk of electric shock if used directly and is incompatible with the rated operating voltage of these devices. Therefore, the living power supply branch 800 is equipped with the transformer 801. The primary winding of the transformer 801 is connected to the output terminal of the main distribution board 5, receiving electrical energy from the power-grade voltage. According to the principle of electromagnetic induction, the alternating current generates alternating magnetic flux in the primary winding. This alternating magnetic flux passes through the iron core and couples to the secondary winding, inducing a lower voltage electromotive force in the secondary winding. By rationally designing the turns ratio of the primary and secondary windings, the power-grade voltage is stepped down to a safe voltage level suitable for living electricity, such as 220V or 380V. The secondary output terminal of the transformer 801 is connected to the low-voltage distribution board 802. The low-voltage distribution board 802 is equipped with multiple low-voltage output circuits. Each circuit is connected to the electrical equipment in each living area on the ship through an independent circuit breaker and leakage protection device. When a short circuit or leakage fault occurs in a certain circuit, the circuit breaker or leakage protection device corresponding to that circuit will quickly act to cut off the faulty circuit without affecting the normal power supply of other circuits, thus ensuring the safety and continuity of the crew's electricity use.

[0042] like Figure 1 As shown, in an optional embodiment, at least two sets of the pure methanol fuel generator 4 are provided, and at least two sets of the pure methanol fuel generator 4 are connected in parallel to the main distribution board 5, and at least two sets of the pure methanol fuel generator 4 serve as backups for each other.

[0043] During ocean voyages, the continuous power supply capability of the propulsion system is directly related to the ship's navigation safety. If the generator set 4 fails, resulting in a complete power loss, the ship will lose its propulsion and maneuverability, and in severe sea conditions, it is highly susceptible to serious accidents such as drifting, grounding, or even capsizing. By setting at least two sets of the pure methanol fuel generator set 4 connected in parallel to the main switchboard 5, under normal navigation conditions, multiple generator sets 4 operate simultaneously and jointly supply power to the main switchboard 5. Each generator set 4 bears the total power load according to the principle of load sharing, so that each generator set 4 operates in a high-efficiency range close to its rated power, avoiding the problem of low efficiency and high fuel consumption rate of a single high-power unit under partial load. When one of the four generator sets needs to be taken out of operation due to mechanical failure, electrical failure, or planned maintenance, the remaining four generator sets can automatically take over the entire power load. The power management function on the main distribution board 5 detects the reduction in the number of operating units and automatically adjusts the output power distribution of the remaining units to ensure uninterrupted power supply to the entire ship, achieving seamless switching between non-stop operation and non-stop navigation, which significantly improves the reliability and safety of the ship's power system during long-distance ocean voyages.

[0044] like Figure 1 As shown, in an optional embodiment, the methanol fuel storage unit 1 is a methanol fuel tank or a methanol fuel storage tank, and the methanol supply unit 2 includes a methanol delivery pump and a methanol delivery pipeline. The inlet end of the methanol delivery pump is connected to the methanol fuel storage unit 1, and the outlet end of the methanol delivery pump is connected to the fuel inlet of the pure methanol fuel engine 3 through the methanol delivery pipeline.

[0045] The methanol fuel storage unit 1 can be selected as either a methanol fuel tank or a methanol fuel storage tank, depending on the ship's hull structure and cabin layout. The methanol fuel tank is a fixed storage space enclosed by the hull structure, suitable for large ocean-going vessels, with a large volume and low center of gravity, which is beneficial to ship stability. The methanol fuel storage tank is an independently installed tank structure, which can be flexibly arranged in available space inside the ship's hull, suitable for small and medium-sized vessels or converted vessels, and is easier to install and replace. The methanol transfer pump is a positive displacement pump or a centrifugal pump. When the methanol transfer pump starts operating, the periodic change in the working volume within the pump chamber or the high-speed rotation of the impeller generates centrifugal force, forming a negative pressure zone below atmospheric pressure at the pump inlet. The methanol fuel in the methanol fuel storage unit 1 is drawn into the pump chamber under the pressure difference between atmospheric pressure and the negative pressure in the pump chamber. Subsequently, it is pressurized at the pump outlet to a transfer pressure higher than the pipeline resistance and engine injection pressure required, flowing along the methanol transfer pipeline to the fuel inlet of the pure methanol fuel engine 3, completing the forced transfer of methanol fuel from the storage location to the combustion location.

[0046] In an optional embodiment, the methanol supply unit 2 further includes a methanol preheating device, which is installed on the methanol delivery pipeline and is used to heat the methanol fuel to a preset temperature range.

[0047] Methanol has a higher viscosity than diesel at room temperature and a larger latent heat of vaporization. If injected directly into the cylinder at room temperature, the methanol droplets will have a larger atomization particle size and a slower evaporation rate, resulting in insufficient uniformity of methanol-air mixing, incomplete combustion, reduced engine thermal efficiency, and increased emissions of unburned methanol and formaldehyde. The methanol preheating device heats the methanol fuel, reducing its viscosity and surface tension. This makes it easier for the methanol to be dispersed into fine droplets when injected into the cylinder, increasing the specific surface area of ​​the droplets, accelerating methanol evaporation and mixing with air, thereby improving the uniformity of the in-cylinder mixture, promoting complete combustion of methanol, increasing the engine's indicated thermal efficiency, and reducing the generation of harmful emissions. The methanol preheating device heats the methanol fuel to a preset temperature range, which is determined based on the physical properties of methanol and the engine's injection system design. Too low a temperature results in insufficient preheating, while too high a temperature may cause vapor lock in the pipeline, affecting fuel supply continuity. Therefore, the heating temperature is controlled within the preset range to balance atomization improvement and fuel supply stability.

[0048] In an optional embodiment, the inner wall of the methanol fuel storage unit 1 is provided with an anti-corrosion layer, which is a coating or lining resistant to methanol corrosion, and the material of the anti-corrosion layer is selected from at least one of epoxy resin coating, polytetrafluoroethylene lining or stainless steel composite plate.

[0049] Methanol is a polar organic solvent that causes swelling and corrosion of common engineering materials such as carbon steel, aluminum alloys, and ordinary rubber. Long-term contact can lead to pitting and uniform corrosion on the carbon steel surface, gradually thinning the tank wall and reducing structural strength. In severe cases, it may cause fuel leakage. The anti-corrosion layer covers the inner wall surface of the methanol fuel storage unit 1, forming a dense isolation barrier between the methanol fuel and the tank substrate, preventing methanol molecules from directly contacting the substrate metal, thereby isolating electrochemical and chemical corrosion. The epoxy resin coating is applied to the inner wall of the tank through a coating process, forming a continuous and dense polymer film after curing, exhibiting excellent methanol penetration resistance and adhesion. The polytetrafluoroethylene lining has extremely low surface energy and extremely high chemical inertness, reacting almost no with any organic solvents, and exhibiting outstanding methanol corrosion resistance. The stainless steel composite plate uses the stainless steel layer as the corrosion-resistant surface in contact with methanol and the carbon steel layer as the load-bearing structural layer, combining corrosion resistance and structural strength. The three materials can be selected or combined according to the ship's cost budget, expected service life and maintenance conditions to provide long-term and reliable corrosion protection for the methanol fuel storage unit 1.

[0050] In an optional embodiment, the inner wall of the methanol fuel storage unit 1 is further provided with a methanol leakage detection device, which includes a liquid level sensor disposed at the bottom of the methanol fuel storage unit 1. When the liquid level sensor detects a liquid level drop rate exceeding a preset threshold, a leakage alarm signal is triggered.

[0051] During long-term operation, methanol fuel storage unit 1 may leak methanol due to reasons such as weld fatigue cracking, loose pipe joints, aging valve seals, or external impact. If not detected in time, the leaked methanol will accumulate inside the hull, causing not only fuel loss but also the formation of a flammable vapor cloud, posing a risk of deflagration upon contact with an open flame or electrical spark. The liquid level sensor continuously monitors the methanol fuel level in methanol fuel storage unit 1. Under normal operating conditions, changes in the liquid level are only caused by engine fuel consumption, and its rate of decline corresponds to the engine's fuel consumption rate, remaining within a predictable and slow range. When methanol fuel storage unit 1 leaks, methanol fuel flows out from the leak point, and the rate of liquid level decline will be significantly higher than the rate corresponding to normal consumption. The liquid level sensor transmits the real-time detected liquid level signal to the ship's centralized monitoring platform. The centralized monitoring platform performs differential calculation on the liquid level signal to obtain the liquid level drop rate, and compares the rate with the preset threshold. When the liquid level drop rate exceeds the preset threshold, it is determined to be an abnormal leakage state, and a leakage alarm signal is immediately triggered to remind the crew to promptly investigate the leak point and take emergency measures to control the leakage risk.

[0052] In an optional embodiment, the methanol leak detection device further includes a methanol vapor concentration sensor disposed around the methanol fuel storage unit 1. When the methanol vapor concentration detected by the methanol vapor concentration sensor exceeds a preset safe concentration, a leak alarm signal is triggered.

[0053] The liquid level sensor indirectly determines the presence of a leak by monitoring changes in the liquid level. However, in the initial stage of a leak when the leakage volume is small, the rate of liquid level drop may not be obvious, resulting in a certain detection lag. The methanol vapor concentration sensor is installed in the peripheral space of the methanol fuel storage unit 1 to directly detect the methanol vapor concentration in the surrounding air in real time. The preset safety concentration is set as a warning value below the lower explosive limit. When the methanol vapor concentration sensor detects that the methanol vapor concentration in the surrounding air exceeds the preset safety concentration, it indicates that methanol vapor has escaped from the methanol fuel storage unit 1, posing a potential leak. At this time, a leak alarm signal is immediately triggered. The methanol vapor concentration sensor and the liquid level sensor constitute a dual detection mechanism. The liquid level sensor performs macroscopic monitoring from the perspective of changes in fuel inventory, while the methanol vapor concentration sensor performs microscopic sensing from the perspective of the diffusion of leak products. The two complement each other in detection principle and form a gradient coverage in detection time, jointly constructing a comprehensive, multi-level safety monitoring system for methanol leaks, maximizing the safety of ships and personnel.

[0054] like Figure 1 As shown, based on the same inventive concept, this application also provides a vessel, which includes the power system as described above. Specifically, in this vessel, except for the power system and related components which adopt the technical solutions in the above embodiments, the structure, connection relationship, installation position, etc. of other devices can refer to the relevant disclosures in the prior art, and will not be described in detail here.

[0055] It should be understood that the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. Although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit, without departing from the scope of the exemplary embodiments of the invention.

[0056] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" in this article describes another relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the related objects before and after it are in an "or" relationship.

[0057] It should be understood that in the description of this invention, the terms "upper," "vertical," "inner," "outer," etc., indicate the orientation or positional relationship as commonly placed when the disclosed product is used, or the orientation or positional relationship commonly understood by those skilled in the art. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0058] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" 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 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 this invention based on the specific circumstances.

[0059] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” “containing,” and / or “including” as used herein specify the presence of the stated features, integers, steps, operations, units, and / or components, and do not exclude the presence or addition of one or more other features, quantities, steps, operations, units, components, and / or combinations thereof.

[0060] Specific details are provided in the following description to provide a complete understanding of the exemplary embodiments. However, those skilled in the art will understand that the exemplary embodiments can be implemented without these specific details. In other embodiments, well-known processes, structures, and techniques may be omitted in the depiction of non-essential details to avoid obscuring the exemplary embodiments.

[0061] The above are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

[0062] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art.

Claims

1. A pure methanol power system, characterized in that, The power system includes: Methanol fuel storage unit, used to store methanol fuel; A methanol supply unit is connected to the methanol fuel storage unit and is used to output methanol fuel from the methanol fuel storage unit; A pure methanol fuel engine is connected to the methanol supply unit, and the pure methanol fuel engine uses methanol fuel as fuel. A generator is connected to the pure methanol fuel engine, and the pure methanol fuel engine drives the generator to generate electrical energy. The pure methanol fuel engine and the generator form a pure methanol fuel generator set. The main distribution board, electrically connected to the generator, is used to receive and distribute the electrical energy generated by the generator; The propulsion branch is electrically connected to the main power distribution board. The propulsion branch includes a propulsion motor, a gearbox, a shaft system, and a propeller connected in sequence. The propulsion branch is used to convert electrical energy into ship propulsion power.

2. The pure methanol power system as described in claim 1, characterized in that: The power system also includes an equipment power supply branch, which is electrically connected to the main switchboard and is used to provide power to the ship's mechanical equipment.

3. The pure methanol power system as described in claim 1, characterized in that: The power system also includes a domestic power supply branch electrically connected to the main switchboard. The domestic power supply branch includes a transformer and a low-voltage switchboard connected in sequence, and is used to provide power to the ship's living facilities and electrical equipment.

4. The pure methanol power system as described in claim 1, characterized in that: The pure methanol fuel generator set is provided in at least two sets, and the at least two sets of pure methanol fuel generator sets are connected in parallel to the main distribution board, and the at least two sets of pure methanol fuel generator sets serve as backups for each other.

5. The pure methanol power system as described in claim 1, characterized in that: The methanol fuel storage unit is a methanol fuel tank or a methanol fuel storage vessel. The methanol supply unit includes a methanol delivery pump and a methanol delivery pipeline. The inlet end of the methanol delivery pump is connected to the methanol fuel storage unit, and the outlet end of the methanol delivery pump is connected to the fuel inlet of the pure methanol fuel engine through the methanol delivery pipeline.

6. The pure methanol power system as described in claim 5, characterized in that: The methanol supply unit also includes a methanol preheating device, which is installed on the methanol delivery pipeline and is used to heat the methanol fuel to a preset temperature range.

7. The pure methanol power system as described in claim 1, characterized in that: The inner wall of the methanol fuel storage unit is provided with an anti-corrosion layer, which is a coating or lining resistant to methanol corrosion. The material of the anti-corrosion layer is selected from at least one of epoxy resin coating, polytetrafluoroethylene lining, or stainless steel composite plate.

8. The pure methanol power system as described in claim 1, characterized in that: The inner wall of the methanol fuel storage unit is also equipped with a methanol leakage detection device, which includes a liquid level sensor located at the bottom of the methanol fuel storage unit. When the liquid level sensor detects a liquid level drop rate exceeding a preset threshold, a leakage alarm signal is triggered.

9. The pure methanol power system according to any one of claims 1 to 8, characterized in that: The methanol leak detection device also includes a methanol vapor concentration sensor located around the methanol fuel storage unit. When the methanol vapor concentration detected by the methanol vapor concentration sensor exceeds a preset safe concentration, a leak alarm signal is triggered.

10. A ship, characterized in that: The vessel includes the propulsion system as described in any one of claims 1-9.

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