Ammonia hybrid power ship power system and control method

Abstract

The invention discloses an ammonia hybrid power ship power system and a control method, the ammonia hybrid power ship power system comprises a power supply assembly, a ship power assembly and an ammonia conveying assembly, and the power supply assembly comprises a storage battery and a generator which are connected with each other; the ship power assembly comprises an ammonia-hydrogen engine unit and a ship propeller, and the ammonia-hydrogen engine unit is connected with the generator and the ship propeller; the ammonia conveying assembly comprises a liquid ammonia source, a liquid ammonia gasifier and an ammonia conveying pipeline, the liquid ammonia gasifier is connected with the ammonia hydrogen engine unit through the ammonia conveying pipeline, the ammonia conveying pipeline is provided with an ammonia decomposition section and a mixing section, an inner sleeve is arranged in the ammonia decomposition section in a sleeved mode, and an ammonia gas overflowing channel is formed between the outer wall of the inner sleeve and the inner wall of the ammonia decomposition section; the inner sleeve is filled with an ammonia decomposition catalyst with a magnetic thermal property, and an inductance coil electrically connected with the power supply assembly is wound on the periphery of the ammonia decomposition section. The problems that an ammonia decomposer is difficult in temperature rise, slow in response, redundant in structure, limited in high-pressure decomposition and the like are solved.

Description

Technical Field

[0001] This invention relates to the technical field of ammonia-hydrogen combustion, specifically to an ammonia-hydrogen hybrid power system for ships and its control method. Background Technology

[0002] Ammonia, as a clean fuel, is considered key to the future energy transition because its combustion process does not produce carbon dioxide and it possesses high energy density and good storage and transportation characteristics. To reduce the environmental impact of engines, the industry is developing ammonia-hydrogen engines for use in marine propulsion systems, aiming to replace traditional diesel engines and achieve zero-carbon marine power.

[0003] However, existing ammonia-hydrogen engine technologies suffer from numerous bottlenecks. Because ammonia must be mixed with hydrogen for combustion, complex heat exchangers and ammonia decomposers are necessary in practical systems. However, engine exhaust temperatures typically cannot reach the high temperatures required for effective ammonia decomposition (usually >800°C), necessitating an additional heat source. Traditional heating methods (such as hydrogen / ammonia-assisted combustion, electric furnaces, or multi-stage heat exchangers) not only significantly complicate the entire marine propulsion system, requiring additional space for installation and maintenance, but also suffer from inherent drawbacks such as low energy efficiency and slow thermal response.

[0004] Meanwhile, traditional ammonia decomposer technology faces more fundamental limitations: Insufficient tolerance to high temperature and high pressure: Due to limitations in material and structural safety, the currently known safe operating conditions are approximately 800℃ and 5 bar, which is insufficient to meet the requirements of higher temperature and high pressure and more efficient decomposition.

[0005] Thermodynamic heat transfer efficiency bottleneck: Constrained by the first law of thermodynamics, there is an upper limit to heat transfer. Existing heat transfer designs for ammonia decomposers are unable to overcome this bottleneck, resulting in a large amount of wasted thermal energy and low overall energy efficiency.

[0006] In summary, existing ammonia decomposers and their supporting systems generally suffer from interconnected technical challenges such as "difficulty in heating up, slow response, structural redundancy, and limited high-pressure decomposition," which severely restrict the practical application and performance improvement of ammonia-hydrogen engines in fields such as marine engineering. Summary of the Invention

[0007] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides an ammonia hybrid power ship propulsion system and control method to solve problems such as difficulty in heating ammonia decomposers, slow response, structural redundancy, and limitations in high-pressure decomposition.

[0008] According to a first aspect of the present invention, an ammonia hybrid power ship propulsion system includes: Power supply components, including interconnected batteries and generators, are used for power supply and generation; A marine power system includes an ammonia-hydrogen engine set and a marine propulsion system. The ammonia-hydrogen engine set is connected to the generator and the marine propulsion system respectively, and is used to provide kinetic energy for the power generation of the power supply system and the operation of the marine propulsion system. An ammonia delivery assembly includes a liquid ammonia source, a liquid ammonia vaporizer, and an ammonia delivery pipeline connected in sequence. The liquid ammonia vaporizer is connected to the ammonia-hydrogen engine unit through the ammonia delivery pipeline. The ammonia delivery pipeline has an ammonia decomposition section and a mixing section arranged in sequence along the internal airflow direction. An axially extending inner sleeve is fitted inside the ammonia decomposition section. The outer diameter of the inner sleeve is smaller than the inner diameter of the ammonia decomposition section. An ammonia gas flow channel with an annular cross-section is formed between the outer wall of the inner sleeve and the inner wall of the ammonia decomposition section. The interior of the inner sleeve is filled with an ammonia decomposition catalyst with magnetocaloric properties. An inductor coil electrically connected to the power supply assembly is wound around the outer periphery of the ammonia decomposition section. The inductor coil is used to apply a magnetic field to the ammonia decomposition catalyst when energized, so as to heat the ammonia decomposition catalyst.

[0009] The ammonia hybrid power ship propulsion system according to embodiments of the present invention has at least the following beneficial effects: In operation, the system is started, and the inductor coil is powered by the battery. The inductor coil is controlled to heat the ammonia decomposition catalyst with a magnetocaloric effect, rapidly raising its temperature to the set operating point. Simultaneously, the liquid ammonia source is controlled, causing the liquid ammonia to be vaporized into high-pressure ammonia gas via the liquid ammonia vaporizer. This gas is then introduced into the ammonia delivery pipeline. After entering the pipeline, the ammonia gas is divided into two paths: one flows through the ammonia decomposition catalyst heated by the inductor coil, and the other flows through an ammonia gas flow channel connected in parallel with the inner sleeve. The ammonia gas flowing through the high-temperature ammonia decomposition catalyst undergoes a decomposition reaction under its action, generating a hydrogen-rich mixed gas. This mixed gas is then rapidly and uniformly mixed with the undecomposed ammonia gas flowing out of the ammonia gas flow channel in the mixing section downstream of the pipeline, forming an ammonia-hydrogen mixed fuel that meets the engine's requirements. This ammonia-hydrogen mixed gas is then introduced into the ammonia-hydrogen engine unit, enabling the engine to start quickly and reliably. After the engine starts running, its output power is used to drive the ship's propeller and generator. The electrical energy generated by the generator is fed back into the battery, thus providing energy for the continuous and stable operation of the inductor coil, forming an efficient energy closed loop.

[0010] This invention creatively employs an inner and outer casing structure, integrating an inductor coil into the ammonia delivery pipeline. It utilizes the ship's electrical power to directly heat the ammonia decomposition catalyst within the pipeline, enabling the high-pressure ammonia to decompose simultaneously during delivery. This is equivalent to embedding the function of a traditionally separate ammonia decomposer into the fuel delivery pipeline itself, eliminating the need for burners, complex heat exchangers, and separate decomposition containers required in traditional solutions. The system structure is revolutionaryly simplified, significantly reducing space requirements, making it particularly suitable for applications on ships with ample installation space. Employing inductive heating technology, energy is directly applied to the catalyst particles through magnetic field coupling, achieving efficient and rapid internal heating. The catalyst bed temperature can be precisely controlled by adjusting the current, with a fast response speed. Unheated ammonia in the parallel ammonia flow channels provides continuous convective cooling to the mixing section and pipe walls, effectively suppressing local overheating and improving system thermal stability and pipeline pressure resistance life. The decomposed high-temperature hydrogen-blended gas and the undecomposed room-temperature / low-temperature ammonia gas converge in the mixing section for rapid heat and mass exchange. This process ensures that the temperature of the mixed fuel entering the ammonia-hydrogen engine is suitable, avoiding overcooling or overheating, and also maintains a high intake fuel density, which is beneficial to the combustion stability and efficiency of the ammonia-hydrogen engine.

[0011] According to some embodiments of the present invention, the ammonia decomposition catalyst includes a first ammonia decomposition catalyst and a second ammonia decomposition catalyst, wherein the first ammonia decomposition catalyst is a catalyst with high magnetocaloric properties and low catalytic efficiency, and the second ammonia decomposition catalyst is a catalyst with low magnetocaloric properties and a noble metal component and high catalytic efficiency. The inner sleeve is provided with at least one ammonia high-heating section and at least one ammonia high-decomposition section along the axial direction, the first ammonia decomposition catalyst is filled in the ammonia high-heating section, and the second ammonia decomposition catalyst is filled in the ammonia high-decomposition section.

[0012] According to some embodiments of the present invention, both the ammonia high heating section and the ammonia high decomposition section are provided with multiple sections, and the ammonia high decomposition section is provided between two adjacent ammonia high heating sections.

[0013] According to some embodiments of the present invention, the ammonia-hydrogen engine unit is provided with an exhaust pipe, the liquid ammonia vaporizer is provided with an exhaust heat exchange channel and a liquid ammonia vaporization channel having a heat exchange relationship between the walls, the exhaust pipe is connected to the inlet of the exhaust heat exchange channel, the liquid ammonia vaporization channel is connected between the liquid ammonia source and the ammonia delivery pipeline, and the outlet of the exhaust heat exchange channel is connected to an exhaust gas processor.

[0014] According to some embodiments of the present invention, the ammonia-hydrogen engine unit includes a generator engine and a mechanical transmission engine, wherein the generator engine is driven to the generator and the mechanical transmission engine is driven to the ship propulsion system.

[0015] According to some embodiments of the present invention, the generator engine is provided with a first exhaust pipe, the mechanical transmission engine is provided with a second exhaust pipe, and the first exhaust pipe and the second exhaust pipe are connected to the exhaust pipe through a mixer.

[0016] According to some embodiments of the present invention, an air source is also included, which is connected to both the power generation engine and the mechanical transmission engine.

[0017] According to some embodiments of the present invention, the ship propulsion assembly further includes a drive motor, which is electrically connected to the power supply assembly, and the drive motor and the mechanical transmission engine are connected to the ship propeller via a transmission system.

[0018] According to some embodiments of the present invention, the battery is connected to a first controller and a second controller. The first controller is connected between the inductor and the battery and is used to control the operating power of the inductor. The second controller is connected between the battery and the drive motor and is used to control the operating power of the drive motor.

[0019] According to a second aspect of the present invention, a control method for a marine propulsion system is applicable to the aforementioned ammonia hybrid power marine propulsion system. The marine propulsion system further includes a drive motor, which is electrically connected to the power supply component and drively connected to the marine propeller. The control method includes: During the cold start phase of the ship's engine, according to the first preset power distribution strategy, the battery is controlled to supply power to both the inductor coil and the drive motor. The inductor coil is controlled to rapidly heat the ammonia decomposition catalyst to the first preset temperature. Simultaneously, according to the first preset supply amount, liquid ammonia is controlled to be vaporized through the liquid ammonia vaporizer. The generated ammonia gas is introduced into the ammonia delivery pipeline. Part of the ammonia gas flows through the high-temperature ammonia decomposition catalyst and is catalytically decomposed into a hydrogen-mixed gas. The other part of the ammonia gas flows directly through the parallel ammonia gas flow channel. The two gas flows merge in the mixing section to form an ammonia-hydrogen mixture, which is then introduced into the ammonia-hydrogen engine unit. The ammonia-hydrogen mixture is used to quickly start the ammonia-hydrogen engine unit. After starting, the ammonia-hydrogen engine unit and the drive motor together provide starting kinetic energy for the ship's propulsion. During the steady-state operation of the ship, the ammonia-hydrogen engine unit is controlled to drive the generator to operate, and the generated electrical energy is stored in the battery. According to the second preset power distribution strategy, the electrical energy of the battery is distributed to the inductor coil and the drive motor. The inductor coil is controlled to maintain the ammonia decomposition catalyst at the second preset temperature. According to the second preset supply amount, liquid ammonia is continuously vaporized and supplied to the system. The ammonia-hydrogen engine unit and the drive motor are controlled to work together to provide stable cruising power for the ship's propulsion. During the high-load operation phase of the ship, the ammonia-hydrogen engine unit is controlled to drive the generator at full power to quickly replenish the battery with electrical energy. According to the third preset power distribution strategy, priority is given to ensuring the peak power requirements of the inductor coil and the drive motor. The inductor coil is controlled to heat the ammonia decomposition catalyst to the third preset temperature to increase the ammonia decomposition rate and the hydrogen doping ratio. According to the third preset supply amount, the liquid ammonia vaporization and supply flow rate are increased. The ammonia-hydrogen engine unit and the drive motor are controlled to jointly provide high-load power for the ship's propulsion.

[0020] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the structure of an ammonia hybrid power ship propulsion system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the ammonia delivery pipeline according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the electrical connection of the inductor coil according to an embodiment of the present invention; Figure 4 This is a flowchart of the control method according to an embodiment of the present invention; Icon labels: Power supply component 100; storage battery 110; generator 120; first controller 130; second controller 140; Marine power components 200; Marine propulsion system 210; Generator engine 220; Mechanical transmission engine 230; Drive motor 240; Transmission system 250; Exhaust pipe 260; Exhaust gas processor 270; Mixer 280; Ammonia conveying assembly 300; liquid ammonia source 310; liquid ammonia vaporizer 320; ammonia conveying pipeline 330; ammonia decomposition section 331; inductor coil 3311; mixing section 332; inner sleeve 333; ammonia high-heating section 3331; ammonia high-decomposition section 3332; ammonia flow channel 334; first ammonia decomposition catalyst 340; second ammonia decomposition catalyst 350; Air source 400. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0024] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0025] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0027] Reference Figures 1 to 3 As shown, the present invention provides the following embodiments of an ammonia hybrid power ship propulsion system: The ammonia hybrid power ship propulsion system of the present invention includes a power supply component 100, a ship propulsion component 200, and an ammonia delivery component 300.

[0028] The power supply component 100 includes a battery 110 and a generator 120 connected to each other. The generator 120 is used to generate electricity, while the battery 110 is used to store and supply electricity.

[0029] The marine power assembly 200 of the present invention includes an ammonia-hydrogen engine set and a marine propulsion unit 210. The ammonia-hydrogen engine set is connected to a generator 120 and a marine propulsion unit 210 respectively. The ammonia-hydrogen engine set is used to provide kinetic energy for the power generation of the power supply assembly 100 and the operation of the marine propulsion unit 210. In actual operation, the ammonia-hydrogen engine set drives the generator 120 and the marine propulsion unit 210 to operate respectively.

[0030] Furthermore, the ammonia-hydrogen engine set in this embodiment includes a generator engine 220 and a mechanical transmission engine 230. The generator engine 220 is connected to the generator 120 and is mainly used to provide kinetic energy for power generation, while the mechanical transmission engine 230 is connected to the ship propulsion unit 210 and is mainly used to provide kinetic energy for the ship's continued operation.

[0031] In some other implementations, the ammonia-hydrogen engine set may be equipped with a single engine that simultaneously powers both the ship's propeller 210 and the generator 120.

[0032] To further improve the speed of the ship's dynamic response and meet different operating conditions, the ship power assembly 200 of the present invention also includes a drive motor 240, which is electrically connected to the power supply assembly 100. The drive motor 240 and the mechanical transmission engine 230 are connected to the ship propeller 210 through the transmission system 250. It is understood that the battery 110 also supplies power to the drive motor 240, and provides kinetic energy to the ship propeller 210 through the drive motor 240 and the mechanical transmission engine 230.

[0033] The ammonia delivery assembly 300 of the present invention includes a liquid ammonia source 310, a liquid ammonia vaporizer 320, and an ammonia delivery pipeline 330 connected in sequence. The liquid ammonia vaporizer 320 is connected to an ammonia-hydrogen engine unit through the ammonia delivery pipeline 330. The ammonia delivery pipeline 330 of the present invention is provided with an ammonia decomposition section 331 and a mixing section 332 arranged in sequence along the internal airflow direction. An inner sleeve 333 extending axially is sleeved inside the ammonia decomposition section 331. The outer diameter of the inner sleeve 333 is smaller than the inner diameter of the ammonia decomposition section 331. The outer wall of the inner sleeve 333 is flush with the ammonia decomposition section 331. An ammonia gas flow channel 334 with an annular cross-section is formed between the inner walls of the ammonia decomposition section 331. The ammonia gas flow channel 334 has a heat exchange relationship with the interior of the inner sleeve 333. The interior of the inner sleeve 333 is filled with an ammonia decomposition catalyst with magnetocaloric properties. An inductor coil 3311 electrically connected to the power supply component 100 is wound around the outer periphery of the ammonia decomposition section 331. The inductor coil 3311 is used to apply a magnetic field to the ammonia decomposition catalyst when energized, so as to heat the ammonia decomposition catalyst. Specifically, the inductor coil 3311 is connected to the battery 110.

[0034] The materials of the ammonia delivery pipeline 330 and the inner sleeve 333 are neither magnetically thermally conductive nor pressure-resistant.

[0035] In operation, the inductor coil 3311 is powered by the battery 110, which controls the inductor coil 3311 to heat the ammonia decomposition catalyst with magnetocaloric effect, causing its temperature to rise rapidly to the set operating point. At the same time, the liquid ammonia source 310 is controlled to vaporize the liquid ammonia into high-pressure ammonia gas through the liquid ammonia vaporizer, and then the gas is introduced into the ammonia delivery pipeline 330. After entering the pipeline, the ammonia gas is divided into two paths: one path flows through the ammonia decomposition catalyst heated by the inductor coil 3311, and the other path flows through the ammonia gas flow passage 334, which is connected in parallel with the inner sleeve 333. The ammonia gas flowing through the high-temperature ammonia decomposition catalyst undergoes a decomposition reaction under the action of the ammonia decomposition catalyst to generate a hydrogen-rich mixed gas. This mixed gas is rapidly and uniformly mixed with the undecomposed ammonia gas flowing out of the ammonia gas flow passage 334 in the mixing section 332 downstream of the pipeline to form an ammonia-hydrogen mixed fuel that meets the requirements of the engine. The ammonia-hydrogen mixed gas is then introduced into the ammonia-hydrogen engine unit to achieve rapid and reliable engine starting.

[0036] In this invention, the battery 110 is connected to a first controller 130 and a second controller 140. The first controller 130 is connected between the inductor coil 3311 and the battery 110, and is used to control the operating power of the inductor coil 3311. The second controller 140 is connected between the battery 110 and the drive motor 240, and is used to control the operating power of the drive motor 240. It can be understood that the power distribution of the battery 110 is controlled by the first controller 130 and the second controller 140 to meet the different operating conditions of the ship.

[0037] To improve energy utilization, the liquid ammonia vaporizer 320 of the present invention is provided with an exhaust heat exchange channel and a liquid ammonia vaporization channel having a heat exchange relationship between the walls. The ammonia-hydrogen engine unit is provided with an exhaust pipe 260, which is connected to the inlet of the exhaust heat exchange channel. The liquid ammonia vaporization channel is connected between the liquid ammonia source 310 and the ammonia delivery pipeline 330. The outlet of the exhaust heat exchange channel is connected to an exhaust gas processor 270.

[0038] The high-temperature exhaust gas generated by the ammonia-hydrogen engine unit is heated and vaporized by the liquid ammonia vaporizer 320. After heat exchange, the exhaust gas is purified by the exhaust gas processor 270 before being discharged.

[0039] Specifically, the generator engine 220 of the present invention is provided with a first exhaust pipe 221, and the mechanical transmission engine 230 is provided with a second exhaust pipe 231. The first exhaust pipe 221 and the second exhaust pipe 231 are connected to the exhaust pipe 260 through a mixer 280.

[0040] The present invention also includes an air source 400, which is connected to both the generator engine 220 and the mechanical transmission engine 230. Based on the operating power of the generator engine 220 and the mechanical transmission engine 230, the air source 400 delivers a set amount of air to the generator engine 220 and the mechanical transmission engine 230 respectively.

[0041] After the ammonia-hydrogen engine set is running, the output power of the generator engine 220 and the mechanical transmission is used to drive the generator 120 and the ship propeller 210, respectively. The electrical energy generated by the generator 120 is fed back to the battery 110, thereby providing energy for the continuous and stable operation of the inductor coil 3311, forming an efficient energy closed loop.

[0042] This invention creatively employs an inner and outer tube structure, integrating the inductor coil 3311 into the ammonia delivery pipeline 330. It utilizes the ship's electricity to directly heat the ammonia decomposition catalyst within the pipeline, enabling the high-pressure ammonia to decompose simultaneously during delivery. This is equivalent to embedding the function of a traditionally independent ammonia decomposer into the fuel delivery pipeline itself, eliminating the need for burners, complex heat exchangers, and separate decomposition containers required in traditional solutions. The system structure is revolutionaryly simplified, significantly reducing space requirements, making it particularly suitable for applications on ships with ample installation space. Using inductive heating technology, energy is directly applied to the catalyst particles through magnetic field coupling, achieving efficient and rapid internal heating. The catalyst bed temperature can be precisely controlled by adjusting the current, with a fast response speed. The unheated ammonia in the parallel ammonia flow channel 334 provides continuous convective cooling to the mixing section 332 and the pipe wall, effectively suppressing local overheating and improving system thermal stability and pipeline pressure resistance life. The decomposed high-temperature hydrogen-blended gas and the undecomposed room-temperature / low-temperature ammonia gas meet in mixing section 332 and undergo rapid heat and mass exchange. This process ensures that the temperature of the mixed fuel entering the ammonia-hydrogen engine is suitable, avoiding overcooling or overheating, and maintains a high intake fuel density, which is beneficial to the combustion stability and efficiency of the ammonia-hydrogen engine.

[0043] Furthermore, this invention has deeply optimized the catalyst arrangement and functional integration to effectively control system costs while ensuring high performance. The specific solution is as follows: To balance heating efficiency and catalytic decomposition efficiency, this invention divides the catalyst bed in the inner sleeve 333 into two functionally complementary sections along the axial direction: High-heating section 3331 for ammonia: It is filled with a first ammonia decomposition catalyst 340. The first ammonia decomposition catalyst 340 has a high magnetocaloric conversion efficiency (i.e., it heats up rapidly under an alternating magnetic field), but its intrinsic catalytic activity for ammonia decomposition is relatively low.

[0044] The ammonia high decomposition section 3332 is filled with a second ammonia decomposition catalyst 350. The second ammonia decomposition catalyst 350 contains active components such as precious metals such as Ru and Pt, and has extremely high intrinsic catalytic activity, but its magnetocaloric effect is relatively weak.

[0045] Both catalysts possess catalytic capabilities, but their catalytic reaction rates differ significantly only at the same temperature. During system operation, gaseous ammonia preferentially flows through the ammonia high-heating section 3331. In this section, the first ammonia decomposition catalyst 340 is efficiently heated by the inductor coil 3311, rapidly raising the temperature of the flowing ammonia to near or at the reaction temperature. Subsequently, the preheated ammonia enters the ammonia high-decomposition section 3332, where, under the action of the second ammonia decomposition catalyst 350 containing highly active precious metals, a rapid and efficient decomposition reaction is achieved.

[0046] To maximize system efficiency and compactness, the following two preferred layout modes can be adopted: Basic configuration: Along the airflow direction, at least one ammonia high heating section 3331 and at least one ammonia high decomposition section 3332 are sequentially set.

[0047] Enhanced Mode (Multi-Segment Alternating Arrangement): To further improve overall decomposition efficiency, multiple ammonia high-heating sections 3331 and ammonia high-decomposition sections 3332 can be arranged alternately along the axial direction. That is, an ammonia high-decomposition section 3332 is set between two adjacent ammonia high-heating sections 3331. This alternating "heating-decomposition-reheating-redecomposition" mode can achieve segmented, stepped heating and deep decomposition of the reactant gas, and is especially suitable for scenarios with long pipelines or high conversion rate requirements.

[0048] The first ammonia decomposition catalyst 340 can be one or more catalysts with high magnetocaloric properties (such as specific ferrite materials), characterized by low cost and rapid heating, and is used to undertake the main heating function. The second ammonia decomposition catalyst 350 can be one or more high-efficiency catalysts supported on noble metals (such as Ru / Al2O3), characterized by high activity and high cost, and is used to undertake the core high-efficiency decomposition function.

[0049] The catalyst partitioning strategy of this invention significantly reduces the amount and cost of precious metals by decoupling the two functions of "efficient heating" and "efficient catalysis" and assigning them to catalysts with different properties. Only a small amount of highly efficient but expensive precious metal catalyst is needed in the critical ammonia high-decomposition section 3332, while a large amount of inexpensive high-magnetothermal material is used in the high-heating section 3331. This significantly reduces the overall material cost of the catalyst without sacrificing overall performance. The high-magnetothermal material enables faster heating response of inductive heating, concentrates heat more within the catalyst bed, reduces heat loss, lowers system thermal inertia, and enhances start-up and load tracking capabilities. Each catalyst operates within its most efficient functional range, making the best use of its resources and avoiding the performance trade-offs or waste that occur when a single catalyst needs to handle both heating and catalysis.

[0050] This invention also proposes a control method for a ship's propulsion system, applicable to the aforementioned ammonia-hydrogen hybrid power ship propulsion system. By precisely controlling electrical energy, ammonia decomposition heat, and propulsion power, the ship's ammonia-hydrogen propulsion system can operate efficiently and stably under different operating conditions, including cold start, steady state, and high load. Figure 4 As shown, the control method of the present invention includes: Step S100: During the cold start phase of the ship's engine, according to the first preset power distribution strategy, the battery 110 is controlled to supply power to the inductor coil 3311 and the drive motor 240 simultaneously. The inductor coil 3311 is controlled to rapidly heat the ammonia decomposition catalyst to the first preset temperature. At the same time, according to the first preset supply amount, the liquid ammonia is controlled to be vaporized through the liquid ammonia vaporizer. The generated ammonia gas is introduced into the ammonia delivery pipeline 330. Part of the ammonia gas flows through the high-temperature ammonia decomposition catalyst and is catalytically decomposed into a hydrogen-mixed gas. The other part of the ammonia gas flows directly through the parallel ammonia gas flow channel 334. The two gas flows merge in the mixing section 332 to form an ammonia-hydrogen mixture, which is then introduced into the ammonia-hydrogen engine unit. The ammonia-hydrogen mixture is used to quickly start the ammonia-hydrogen engine unit. After starting, the ammonia-hydrogen engine unit and the drive motor 240 together provide starting kinetic energy for the ship's propulsion unit 210. Step S200: During the steady-state operation of the ship, the ammonia-hydrogen engine group drives the generator 120 to operate. The generated electrical energy is stored in the battery 110. According to the second preset power distribution strategy, the electrical energy of the battery 110 is distributed to the inductor coil 3311 and the drive motor 240. The inductor coil 3311 is controlled to maintain the ammonia decomposition catalyst at the second preset temperature. According to the second preset supply amount, liquid ammonia is continuously vaporized and supplied to the system. The ammonia-hydrogen engine group and the drive motor 240 are controlled to work together to provide stable cruising power for the ship propulsion 210. Step S300: During the high-load operation phase of the ship, control the ammonia-hydrogen engine to drive the generator 120 at full power to quickly replenish the battery 110 with electrical energy. According to the third preset power distribution strategy, prioritize the peak power requirements of the inductor coil 3311 and the drive motor 240. Control the inductor coil 3311 to heat the ammonia decomposition catalyst to the third preset temperature to increase the ammonia decomposition rate and the hydrogen doping ratio. According to the third preset supply, increase the liquid ammonia vaporization and supply flow rate. Control the ammonia-hydrogen engine and the drive motor 240 to jointly provide high-load power for the ship's propulsion 210.

[0051] This invention utilizes an inner and outer jacket structure within the ammonia delivery pipeline 330 and introduces inductive heating. During navigation, surplus electrical energy from the ship's hybrid power system is directly used in the ammonia decomposition section 331 to activate a magnetocaloric ammonia decomposition catalyst. This allows high-pressure ammonia to decompose simultaneously as it flows through the pipeline, continuously generating a hydrogen-containing mixture that merges with undecomposed ammonia in real-time and supplies it to the ammonia-hydrogen engine. Thus, while retaining the original hybrid power architecture, a single pipeline doubles as a high-pressure ammonia decomposition reactor, eliminating the need for combustion heating devices, multi-stage heat exchangers, and additional decomposition containers required by traditional ammonia-powered systems. This significantly simplifies the system structure and reduces space requirements. Inductive heating acts only on the catalyst, avoiding direct gas heating and preventing continuous contact between high-temperature gas and the pipe wall. This enables safe and rapid ammonia decomposition under high pressure conditions. Furthermore, the convective cooling effect of ammonia in the ammonia flow channel 334 suppresses overheating, improving system stability and pipe wall pressure resistance. The resulting hydrogen enters the engine along with the main fuel, ammonia, increasing the laminar combustion speed and mitigating ammonia fuel ignition delay and combustion fluctuations, allowing the engine to maintain stable output under low-speed, high-load marine operating conditions.

[0052] The catalyst is arranged in sections along the radial central region. The catalyst bed in the inner sleeve 333 is divided axially into a functionally complementary ammonia high-heating section 3331 and ammonia high-decomposition section 3332. The ammonia high-heating section 3331 is filled with a first ammonia decomposition catalyst 340 with high magnetocaloric conversion efficiency to respond quickly to inductive excitation. The ammonia high-decomposition section 3332 is filled with a second ammonia decomposition catalyst 350 with extremely high intrinsic catalytic activity to balance conversion efficiency and precious metal usage, thereby achieving catalyst cost control and efficient utilization.

[0053] This solution addresses the problems of difficult heating, slow response, structural redundancy, and limited high-pressure decomposition in ammonia decomposers, achieving a comprehensive effect of zero carbon emissions, compact structure, instant high-pressure decomposition, second-level response, improved energy utilization, and reduced overall cost, thus forming an overall solution for ammonia hybrid power ships suitable for both ocean and coastal routes.

[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An ammonia hybrid power marine propulsion system, characterized in that, include: Power supply components, including interconnected batteries and generators, are used for power supply and generation; A marine power system includes an ammonia-hydrogen engine set and a marine propulsion system. The ammonia-hydrogen engine set is connected to the generator and the marine propulsion system respectively, and is used to provide kinetic energy for the power generation of the power supply system and the operation of the marine propulsion system. An ammonia delivery assembly includes a liquid ammonia source, a liquid ammonia vaporizer, and an ammonia delivery pipeline connected in sequence. The liquid ammonia vaporizer is connected to the ammonia-hydrogen engine unit through the ammonia delivery pipeline. The ammonia delivery pipeline has an ammonia decomposition section and a mixing section arranged in sequence along the internal airflow direction. An axially extending inner sleeve is fitted inside the ammonia decomposition section. The outer diameter of the inner sleeve is smaller than the inner diameter of the ammonia decomposition section. An ammonia gas flow channel with an annular cross-section is formed between the outer wall of the inner sleeve and the inner wall of the ammonia decomposition section. The interior of the inner sleeve is filled with an ammonia decomposition catalyst with magnetocaloric properties. An inductor coil electrically connected to the power supply assembly is wound around the outer periphery of the ammonia decomposition section. The inductor coil is used to apply a magnetic field to the ammonia decomposition catalyst when energized, so as to heat the ammonia decomposition catalyst.

2. The ammonia hybrid power ship propulsion system according to claim 1, characterized in that: The ammonia decomposition catalyst includes a first ammonia decomposition catalyst and a second ammonia decomposition catalyst. The first ammonia decomposition catalyst is a catalyst with high magnetocaloric properties and low catalytic efficiency, while the second ammonia decomposition catalyst is a catalyst with low magnetocaloric properties and a noble metal component and high catalytic efficiency. The inner sleeve is provided with at least one ammonia high-heating section and at least one ammonia high-decomposition section along the axial direction. The first ammonia decomposition catalyst is filled in the ammonia high-heating section, and the second ammonia decomposition catalyst is filled in the ammonia high-decomposition section.

3. The ammonia hybrid power marine propulsion system according to claim 2, characterized in that: Both the high-heating section and the high-decomposition section of ammonia are provided in multiple sections, and the high-decomposition section of ammonia is provided between two adjacent high-heating sections.

4. The ammonia hybrid power marine propulsion system according to claim 1, characterized in that: The ammonia-hydrogen engine unit is equipped with an exhaust pipe, and the liquid ammonia vaporizer is equipped with an exhaust heat exchange channel and a liquid ammonia vaporization channel with a heat exchange relationship between the two walls. The exhaust pipe is connected to the inlet of the exhaust heat exchange channel, the liquid ammonia vaporization channel is connected between the liquid ammonia source and the ammonia delivery pipeline, and the outlet of the exhaust heat exchange channel is connected to an exhaust gas processor.

5. The ammonia hybrid power marine propulsion system according to claim 4, characterized in that: The ammonia-hydrogen engine unit includes a generator engine and a mechanical transmission engine. The generator engine is connected to the generator, and the mechanical transmission engine is connected to the ship's propulsion system.

6. The ammonia hybrid power marine propulsion system according to claim 5, characterized in that: The generator engine is equipped with a first exhaust pipe, and the mechanical transmission engine is equipped with a second exhaust pipe. The first exhaust pipe and the second exhaust pipe are connected to the exhaust pipe through a mixer.

7. The ammonia hybrid power marine propulsion system according to claim 5, characterized in that: It also includes an air source, which is connected to both the generator engine and the mechanical transmission engine.

8. The ammonia hybrid power ship propulsion system according to claim 5, characterized in that: The ship's power assembly also includes a drive motor, which is electrically connected to the power supply assembly. The drive motor and the mechanical transmission engine are connected to the ship's propulsion system via a transmission system.

9. The ammonia hybrid power marine propulsion system according to claim 8, characterized in that: The battery is connected to a first controller and a second controller. The first controller is connected between the inductor and the battery and is used to control the operating power of the inductor. The second controller is connected between the battery and the drive motor and is used to control the operating power of the drive motor.

10. A control method for a ship's propulsion system, characterized in that, The ammonia hybrid power marine propulsion system as described in any one of claims 1 to 9, wherein the marine propulsion assembly further includes a drive motor, the drive motor being electrically connected to the power supply assembly and drivingly connected to the marine propeller, and the control method comprising: During the cold start phase of the ship's engine, according to the first preset power distribution strategy, the battery is controlled to supply power to both the inductor coil and the drive motor. The inductor coil is controlled to rapidly heat the ammonia decomposition catalyst to the first preset temperature. Simultaneously, according to the first preset supply amount, liquid ammonia is controlled to be vaporized through the liquid ammonia vaporizer. The generated ammonia gas is introduced into the ammonia delivery pipeline. Part of the ammonia gas flows through the high-temperature ammonia decomposition catalyst and is catalytically decomposed into a hydrogen-mixed gas. The other part of the ammonia gas flows directly through the parallel ammonia gas flow channel. The two gas flows merge in the mixing section to form an ammonia-hydrogen mixture, which is then introduced into the ammonia-hydrogen engine unit. The ammonia-hydrogen mixture is used to quickly start the ammonia-hydrogen engine unit. After starting, the ammonia-hydrogen engine unit and the drive motor together provide starting kinetic energy for the ship's propulsion. During the steady-state operation of the ship, the ammonia-hydrogen engine unit is controlled to drive the generator to operate, and the generated electrical energy is stored in the battery. According to the second preset power distribution strategy, the electrical energy of the battery is distributed to the inductor coil and the drive motor. The inductor coil is controlled to maintain the ammonia decomposition catalyst at the second preset temperature. According to the second preset supply amount, liquid ammonia is continuously vaporized and supplied to the system. The ammonia-hydrogen engine unit and the drive motor are controlled to work together to provide stable cruising power for the ship's propulsion. During the high-load operation phase of the ship, the ammonia-hydrogen engine unit is controlled to drive the generator at full power to quickly replenish the battery with electrical energy. According to the third preset power distribution strategy, priority is given to ensuring the peak power requirements of the inductor coil and the drive motor. The inductor coil is controlled to heat the ammonia decomposition catalyst to the third preset temperature to increase the ammonia decomposition rate and the hydrogen doping ratio. According to the third preset supply amount, the liquid ammonia vaporization and supply flow rate are increased. The ammonia-hydrogen engine unit and the drive motor are controlled to jointly provide high-load power for the ship's propulsion.

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