Novel ship comprehensive energy system and method integrating organic Rankine cycle waste heat recovery

Abstract

The invention discloses a novel ship comprehensive energy system and method integrating organic Rankine cycle waste heat recovery, and belongs to the field of ship comprehensive energy design. The system comprises a dual-fuel engine, a dual-fuel generator set, a fuel cell, a waste heat boiler, a shaft-driven motor, a lithium battery, an electric refrigerator, a heat pump, an organic Rankine cycle, carbon capture equipment, a carbon trading mechanism, mechanical, electric, heat and cold load requirements in the ship operation process and other accessories. According to the system, by optimizing an energy structure (such as renewable energy storage) and a carbon capture means, the economical efficiency is improved, the double-control target of carbon emission is achieved, the compliance requirements of international maritime affair environmental protection laws and regulations are effectively supported, and green and sustainable development of ships is assisted.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of ship integrated energy design, and particularly relates to a novel ship integrated energy system integrated with an organic Rankine cycle waste heat recovery and a method thereof. BACKGROUND

[0002] As an important transport carrier for global trade, ships pursue higher energy utilization efficiency, and the integration and application of waste heat recovery technology and new energy systems become a key research direction. At present, large ships generally use high-power diesel engines or dual-fuel engines as the main power source, but the thermal efficiency is usually less than 50%, more than half of the fuel chemical energy is discharged into the environment in the form of low-temperature waste heat (such as main engine flue gas, cylinder sleeve cooling heat), causing huge energy waste. In order to recover this part of waste heat, the industry has explored various technical paths. Among them, the organic Rankine cycle (ORC) technology is considered as an ideal choice for ship waste heat recovery due to its high efficiency and adaptability in recovering low-grade waste heat. In the prior art, there are schemes to directly integrate the ORC system in the main engine flue for waste heat power generation, but such designs directly contacting flue gas are prone to cause carbon deposition and corrosion of the evaporator, and increase the exhaust back pressure of the main engine, which counteracts the efficiency of the main engine, and the long-term reliability and economy of the system face challenges.

[0003] At present, the most potential emission reduction market mechanisms in the international shipping industry include the maritime greenhouse gas fund mechanism and the international maritime carbon trading mechanism. The application of carbon trading concept to the field of ships helps to comprehensively evaluate the energy efficiency of ships and improve the market competitiveness of ship development. Through the system integration of hardware low-carbon technology and the collaborative optimization of market mechanism management, the economy and low-carbon nature of the system are evaluated. At the same time, in order to cope with diversified ship load demand, the concept of integrated energy system emerges as the times require. Traditional ship energy systems often focus on the supply of a single energy form (such as mechanical propulsion or power supply), and do not adequately consider the collaborative optimization of multiple loads such as electricity, heat, and cold. Each energy subsystem (such as a generator set, a boiler, and a refrigerator) usually operates independently, lacks unified scheduling, and results in low overall energy utilization efficiency. Although attempts have been made to integrate new energy devices such as fuel cells and lithium batteries in the prior art, how to deeply couple these devices with the waste heat recovery system to form a collaborative network that can adaptively schedule and stably meet the multiple energy loads of the whole ship is still a technical difficulty.

[0004] Therefore, the prior art has the following obvious deficiencies: 1. The compatibility and reliability of the waste heat recovery technology with the ship main engine are poor, and safe, efficient, and deep recovery cannot be achieved.

[0005] 2. The energy supply system is in an "island" state, lacks collaborative planning and optimal scheduling of mechanical, electrical, thermal, and cold multi-energy flows, and the overall energy efficiency needs to be improved.

[0006] 3. The coupling degree of emission reduction technology and energy system is low, and it is difficult to realize systematic control of carbon emission under the premise of ensuring economy.

[0007] Therefore, it is crucial to construct a new type of ship integrated energy system based on multi-energy coupling, which organically integrates large lithium batteries, fuel cells, organic Rankine cycle waste heat recovery and carbon capture and carbon trading, so as to realize full utilization of energy and collaborative control of carbon emission. SUMMARY

[0008] The technical problem to be solved is: In order to avoid the shortcomings of the prior art, the present application provides a new type of ship integrated energy system integrated with organic Rankine cycle waste heat recovery and a method, which can fully meet the energy demand of machinery, electricity, heat and cold during ship navigation through coordinated operation of each device, and ensure normal operation of the system. The organic Rankine cycle is an indirect ship exhaust waste heat recovery scheme, which first uses the exhaust waste heat of the ship main engine and auxiliary machinery to drive the boiler to generate high-temperature steam, and then the steam is used as a secondary heat source to heat the working medium in the evaporator of the organic Rankine cycle system. Sea water is used as a cooling medium, and the cycle is regenerated through each device, which can continuously convert waste heat into useful electric energy, reduce the output of other devices, and improve energy utilization and economy. The present application fundamentally solves the systematic problem of energy comprehensive utilization and collaborative control of carbon emission of the ship.

[0009] The technical scheme of the present application is: a new type of ship integrated energy system integrated with organic Rankine cycle waste heat recovery, comprising: a dual-fuel engine 1, a dual-fuel generator set 2, a fuel cell 3, a waste heat boiler 4, an axle generator 5, a lithium battery 6, an electric refrigerator 7, a heat pump 8, an organic Rankine cycle subsystem and a carbon capture device 14. The organic Rankine cycle subsystem adopts an indirect heat exchange mechanism, which includes two-stage heat conversion process: first stage, using the exhaust waste heat of the ship main engine and auxiliary machinery to drive the boiler to generate high-temperature steam as an intermediate heat carrier; second stage, making the high-temperature steam flow into the evaporator of the organic Rankine cycle system as a secondary heat source to indirectly heat the organic working medium and make it evaporate and do work; The dual-fuel engine 1 and the axle generator 5 constitute a hybrid power propulsion system for meeting the mechanical load demand of the ship; The electric energy generated by the dual-fuel generator set 2, the fuel cell 3, the lithium battery 6 and the axle generator 5 in PTO mode, and the electric energy generated by the organic Rankine cycle subsystem, are jointly connected to the ship power grid for meeting the electrical load demand of the ship; The electric refrigerator 7 and the heat pump 8 are connected to the ship power grid for meeting the cold load and heat load demand of the ship, respectively; The waste heat boiler 4 is used for recovering waste heat of exhaust gas discharged by the dual-fuel engine 1, the dual-fuel generator set 2 and the fuel cell 3, and generating high-temperature steam; The evaporator is connected with the waste heat boiler 4, and high-temperature steam is used as a secondary heat source to heat an organic Rankine cycle working medium; The carbon capture device 14 is used for treating ship exhaust gas to reduce carbon emissions; The system is controlled by a cooperative scheduling mechanism, which is configured to: For power supply, the electric energy generated by the organic Rankine cycle subsystem and the shaft-mounted electric machine 5 in the PTO mode is preferentially enabled; if the demand is still not met, the lithium battery 6 is discharged, the dual-fuel generator set 2 and the fuel cell 3 are sequentially enabled; if the electric energy generated by the organic Rankine cycle subsystem is surplus, the lithium battery 6 is charged; thus, the coupling and cascade utilization of mechanical, electrical, thermal and cold multi-energy flows, and the cooperation of energy efficiency improvement and carbon emission control are realized. A further technical solution of the present application is that the organic Rankine cycle subsystem comprises an evaporator 9, an expander 10, a generator 11, a condenser 12 and a working medium pump 13 connected by pipelines; and a working process is as follows: After being pressurized by the working medium pump 13, the liquid organic working medium enters the evaporator 9, absorbs heat energy released from high-temperature steam generated by the boiler, and is converted into high-temperature and high-pressure gaseous working medium; The high-temperature and high-pressure gaseous working medium then enters the expander 10 to expand and do work, and drives the connected generator 11 to generate electricity; The low-pressure gaseous working medium discharged from the expander 10 enters the condenser 12 and is condensed into liquid under the action of a cooling medium; The liquid working medium finally returns to the working medium pump 13, completing a closed thermodynamic cycle; The organic Rankine cycle working medium is R365mfc.

[0010] A further technical solution of the present application is that in the hybrid propulsion system, the output shaft of the dual-fuel engine 1 is coupled with the shaft-mounted electric machine 5 through a gear box, and the two jointly drive the propeller; The shaft-mounted electric machine 5 has two working modes of PTI and PTO; In the PTI mode, when the dual-fuel engine 1 fails or its load rate is lower than the minimum running load rate, the shaft-mounted electric machine 5 acts as a motor and is powered by the dual-fuel generator set 2 and / or the fuel cell 3 through the power grid to assist or independently provide propulsion power; In the PTO mode, when the load rate of the dual-fuel engine 1 is higher than a set threshold, the shaft-mounted electric machine 5 acts as a generator to convert the surplus mechanical energy of the main engine into electric energy and input into the ship power grid.

[0011] A further technical solution of the present application is that the carbon capture device 14 adopts a solution absorption method, uses a caustic soda solution as an absorbent, reacts with carbon dioxide in the exhaust gas to generate a sodium carbonate solution, thereby realizing the fixation and removal of carbon dioxide. A further technical solution of the present application is that the cooperative scheduling mechanism is further configured to: For the mechanical load 15 requirement, the dual-fuel engine 1 is preferentially satisfied; When the dual-fuel engine 1 fails or the load rate is insufficient, the shaft generator 5 intervenes in the PTI mode to provide propulsion power together with the ship auxiliary machine. A further technical solution of the present application is that the system integration step carbon trading mechanism is based on the difference between the actual carbon emissions of the ship and the free quota, and uses a step price model to calculate the carbon trading cost, that is, the greater the purchased quota amount, the higher the unit quota price applied, thereby constituting an economic incentive for the low-carbon operation of the system.

[0012] An optimization operation method of the new ship integrated energy system, comprising the following steps: Step 1: Collect the exhaust gas waste heat discharged by the dual-fuel engine 1, the dual-fuel generator set 2 and the fuel cell 3 through the waste heat boiler 4 to generate high-temperature steam; Step 2: Use the high-temperature steam as a heat source of the organic Rankine cycle subsystem to heat the organic working medium in the evaporator 9, drive the expander 10 and the generator 11 to generate electricity, and convert the waste heat into electrical energy; Step 3: Dynamically allocate each energy through the cooperative scheduling mechanism to meet the mechanical load 15, electrical load 16, thermal load 17 and cold load 18 requirements of the ship.

[0013] A further technical solution of the present application is that the working process of the organic Rankine cycle subsystem in step S2 is: The liquid organic working medium R365mfc is pressurized by the working medium pump 13 and enters the evaporator 9 to absorb the heat energy of the high-temperature steam, and becomes high-temperature and high-pressure steam; The high-temperature and high-pressure steam enters the expander 10 to expand and do work, and drives the generator 11 to output electrical energy; The low-pressure gaseous working medium after doing work enters the condenser 12 and is cooled and condensed into liquid by seawater; The liquid working medium returns to the storage tank to complete a cycle.

[0014] A further technical solution of the present application is that the cooperative scheduling mechanism in step 3 specifically includes: Power dispatching steps: Prioritize the use of the power generated by the organic Rankine cycle subsystem and the shaft motor 5 in PTO mode to meet the power demand of the electrical load 16, electric chiller 7 and heat pump 8; if there is a shortage, the lithium battery 6 is discharged, the dual-fuel generator set 2 is started, and the fuel cell 3 is started in sequence to supplement the power; if there is surplus power, the lithium battery 6 is charged. Mechanical energy dispatching steps: Dual-fuel engine 1 is used first to meet the mechanical load 15 demand; when dual-fuel engine 1 fails or the load rate is insufficient, the PTI mode of shaft motor 5 is started to provide propulsion power together with the auxiliary machine; Cooling and heating energy scheduling steps: The electric chiller 7 and heat pump 8 directly meet the cooling load 17 and heating load 18 requirements, respectively. A further technical solution of the present invention includes a carbon trading cost calculation step. The actual carbon emissions during the operation of the accounting system; Compare actual emissions with free carbon emission allowances; If the actual emissions exceed the free allowance, the corresponding allowance will be purchased according to the preset tiered carbon price based on the amount of the excess. The greater the excess, the higher the unit carbon price. If the actual emissions do not exceed the free allowance, the remaining allowance will be sold on the carbon market to generate revenue.

[0015] Beneficial effects The beneficial effects of this invention are as follows: This invention integrates large-scale lithium batteries, fuel cells, organic Rankine cycle waste heat recovery equipment, carbon trading mechanisms, and complex and variable mechanical, electrical, thermal, and cooling loads. Mechanical loads are met collaboratively by the dual-fuel engine and shaft-driven motor, while electrical loads are covered by the organic Rankine cycle, dual-fuel generator set, fuel cell, lithium battery, and shaft-driven motor. When the main engine load is insufficient or malfunctions, auxiliary equipment such as the shaft-driven motor automatically intervenes. Power demand is initially met by the organic Rankine cycle, shaft-driven motor, and lithium battery; if insufficient, backup sources (such as the dual-fuel generator set and fuel cell) are activated sequentially. This cascaded response mechanism makes the system highly flexible, automatically adapting to fluctuating demands during navigation, ensuring a continuous and stable supply of propulsion power, electrical, and thermal loads, and significantly improving the reliability and adaptability of ship operation.

[0016] This invention collects waste heat generated by the main engine and auxiliary equipment using a waste heat boiler, and then drives an organic Rankine cycle to convert the waste heat into electrical energy. This avoids the waste of traditional energy sources and allows for the efficient recovery and utilization of previously discarded heat resources. This directly improves overall energy efficiency, reduces dependence on primary fuel, and decreases fuel consumption and related costs. Simultaneously, the electricity generated by the organic Rankine cycle prioritizes the ship's needs, and any excess can be stored in lithium batteries and used to support heat and cooling loads through energy conversion equipment (such as electric chillers and heat pumps). This multi-source synergy mechanism ensures that every portion of energy is utilized to the maximum extent, thereby optimizing economics and achieving energy conservation and emission reduction goals.

[0017] This invention integrates carbon capture equipment within the system, directly capturing carbon dioxide from emission sources and significantly reducing the carbon footprint of ships during operation. Simultaneously, the organic Rankine cycle waste heat recovery technology reduces reliance on external fossil fuel power generation, thereby reducing indirect emissions, while the priority use of clean energy components such as dual-fuel engines and fuel cells further promotes the low-carbon transition. Overall, by optimizing the energy structure (such as renewable energy storage) and carbon capture methods, the system not only improves economic efficiency but also achieves dual carbon emission control targets, effectively supporting compliance requirements of international maritime environmental regulations and contributing to the green and sustainable development of ships. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a novel integrated ship energy system that integrates organic Rankine cycle waste heat recovery. Figure 2 This is a schematic diagram of an organic Rankine cycle waste heat recovery subsystem. Figure 3 This is a schematic diagram of the structure of a ship's hybrid mechanical propulsion subsystem; Figure 4 This is a flowchart of the carbon trading mechanism for integrated ship energy systems.

[0019] Explanation of reference numerals in the attached drawings: 1. Dual-fuel engine, 2. Dual-fuel generator set, 3. Fuel cell, 4. Waste heat boiler, 5. Shaft-driven motor, 6. Lithium battery, 7. Electric chiller, 8. Heat pump, 9. Evaporator, 10. Expander, 11. Generator, 12. Condenser, 13. Working fluid pump, 14. Carbon capture device, 15. Mechanical load, 16. Electrical load, 17. Cooling load, 18. Heat load. Detailed Implementation

[0020] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0021] Integrated shipboard energy systems have emerged as a new energy management model, achieving more efficient energy utilization by organically integrating multiple energy technologies. Within this framework, organic Rankine cycle waste heat recovery can be deeply coupled with new energy technologies (such as fuel cells and hybrid power systems) to construct a multi-energy complementary network, ultimately maximizing ship energy efficiency and minimizing emissions. While balancing system economics and low-carbon performance, carbon trading mechanisms also offer new approaches to reducing carbon emissions.

[0022] This application provides a novel integrated marine energy system that integrates organic Rankine cycle waste heat recovery, addressing the challenges of stable supply to multiple energy loads, low energy utilization, and severe carbon emissions during ship operation. The system comprises a main engine (dual-fuel engine), auxiliary engines (dual-fuel generator set, fuel cell), a boiler (waste heat boiler), energy efficiency equipment (shaft-driven motor), energy storage equipment (lithium battery), energy conversion equipment (electric chiller, heat pump), an organic Rankine cycle (evaporator, expander, generator, condenser, working fluid pump), and emission reduction equipment (carbon capture). The main engine, as the core component of the ship's propulsion system, primarily provides propulsion power to ensure normal navigation. Auxiliary engines support various auxiliary systems and functions, such as power supply, mechanical operation, and other necessary daily operational services. The boiler mainly collects waste heat generated by the main engine and auxiliary engines during ship operation, providing an input heat source for the organic Rankine cycle. The organic Rankine cycle converts the waste heat into electrical energy as a supplementary energy source, and a large lithium battery is incorporated to increase system flexibility. The energy conversion equipment converts electrical energy into heat and cold energy for energy supply. Carbon reduction equipment has been specifically incorporated to address ship emissions and reduce CO2 emissions during ship operation. During normal navigation, ships have energy demands for machinery, electricity, heat, and cooling. Mechanical loads are met jointly by the dual-fuel engine and shaft-driven motor, with the dual-fuel engine taking priority. In the event of a dual-fuel engine failure, the shaft-driven motor, along with auxiliary machinery, provides propulsion power. Alternatively, when the dual-fuel engine load rate falls below the minimum operating load rate, the shaft-driven motor enhances propulsion. The dual-fuel generator set, fuel cell, lithium battery, shaft-driven motor, and organic Rankine cycle are used to meet electrical demands. If the electricity generated by the organic Rankine cycle and shaft-driven motor is insufficient to meet the total electrical energy demand (ship electrical load, electric cooling, and electric heating), the dual-fuel generator set provides the remaining power. If this is still insufficient, the lithium battery supplements the load. The fuel cell is activated only when the lithium battery reaches its minimum capacity. If there is still surplus electricity after the organic Rankine cycle meets the total electrical energy demand, the excess is stored in the lithium battery. Heat and cooling demands are met by an electric chiller and a heat pump, respectively. By coordinating and scheduling various devices, the energy needs of ships during operation can be stably met, improving system economy and reducing carbon emissions.

[0023] This system fully integrates electromechanical combined heat and cooling systems with waste heat recovery technologies, combining large-scale lithium batteries, fuel cells, ORC waste heat recovery, and carbon trading mechanisms to construct a new type of integrated ship energy system. The specific plan is as follows: This invention proposes a novel integrated marine energy system that integrates organic Rankine cycle waste heat recovery, comprising: a dual-fuel engine 1, a dual-fuel generator set 2, a fuel cell 3, a waste heat boiler 4, a shaft-driven motor 5, a lithium battery 6, an electric chiller 7, a heat pump 8, an organic Rankine cycle subsystem, and a carbon capture device 14. The organic Rankine cycle subsystem adopts an indirect heat exchange mechanism, which includes a two-stage heat conversion process: the first stage uses the waste heat from the exhaust gas of the ship's main engine and auxiliary engines to drive the boiler and generate high-temperature steam as an intermediate heat carrier; the second stage uses the high-temperature steam as a secondary heat source to flow into the evaporator of the organic Rankine cycle system, where the organic working fluid is indirectly heated and evaporated to do work. The dual-fuel engine 1 and the shaft-driven motor 5 constitute a hybrid propulsion system, which is used to work together to meet the mechanical load 15 requirements of the ship. The electrical energy generated by the dual-fuel generator set 2, fuel cell 3, lithium battery 6, and shaft motor 5 in PTO mode, as well as the electrical energy generated by the organic Rankine cycle subsystem, are connected to the ship's electrical grid to collaboratively meet the ship's electrical load 16 requirements. The electric chiller 7 and the heat pump 8 are connected to the ship's electrical grid to meet the ship's cooling load 17 and heating load 18 requirements, respectively. The waste heat boiler 4 is used to recover the waste heat from the exhaust gases emitted by the dual-fuel engine 1, the dual-fuel generator set 2, and the fuel cell 3 to generate high-temperature steam. The evaporator 9 is connected to the waste heat boiler 4, and uses the high-temperature steam as a secondary heat source to heat the organic Rankine cycle working fluid. The carbon capture device 14 is used to treat ship exhaust gas in order to reduce carbon emissions; The system is controlled through a cooperative scheduling mechanism, which is configured as follows: For power supply, the organic Rankine cycle subsystem and the shaft motor 5 in PTO mode are used first; if the demand is still not met, the lithium battery 6 is discharged, the dual-fuel generator set 2 and the fuel cell 3 are activated in sequence; if the electrical energy generated by the organic Rankine cycle subsystem is surplus, the lithium battery 6 is charged; in this way, the coupling and cascade utilization of mechanical, electrical, thermal and cold multi-energy flows are realized, as well as the synergy between energy efficiency improvement and carbon emission control. This invention also proposes an optimized operation method for the novel ship integrated energy system, comprising the following steps: Step 1: Collect waste heat from the exhaust gases emitted by the dual-fuel engine 1, dual-fuel generator set 2, and fuel cell 3 through the waste heat boiler 4 to generate high-temperature steam; Step 2: Using the high-temperature steam as the heat source of the organic Rankine cycle subsystem, the organic working fluid is heated in the evaporator 9 to drive the expander 10 and the generator 11 to generate electricity, converting waste heat into electrical energy. Step 3: Through a collaborative scheduling mechanism, dynamically allocate energy resources to meet the ship's mechanical load 15, electrical load 16, thermal load 17, and cooling load 18 requirements.

[0024] Specifically, the workflow of the organic Rankine cycle subsystem in step S2 is as follows: After being pressurized by the working fluid pump 13, the liquid organic working fluid R365mfc enters the evaporator 9 to absorb the heat energy of the high-temperature steam and become high-temperature and high-pressure steam. The high-temperature, high-pressure steam enters the expander 10, expands, and does work, driving the generator 11 to output electrical energy. After performing work, the low-pressure gaseous working fluid enters the condenser 12 and is cooled and condensed into a liquid by seawater. The liquid working fluid returns to the storage tank, completing one cycle.

[0025] Specifically, the collaborative scheduling mechanism in step 3 includes: Power dispatching steps: Prioritize the use of the power generated by the organic Rankine cycle subsystem and the shaft motor 5 in PTO mode to meet the power demand of the electrical load 16, electric chiller 7 and heat pump 8; if there is a shortage, the lithium battery 6 is discharged, the dual-fuel generator set 2 is started, and the fuel cell 3 is started in sequence to supplement the power; if there is surplus power, the lithium battery 6 is charged. Mechanical energy dispatching steps: Dual-fuel engine 1 is used first to meet the mechanical load 15 demand; when dual-fuel engine 1 fails or the load rate is insufficient, the PTI mode of shaft motor 5 is started to provide propulsion power together with the auxiliary machine; Cooling and heating energy scheduling steps: The electric chiller 7 and heat pump 8 directly meet the cooling load 17 and heating load 18 requirements, respectively. Specifically, this also includes the steps for calculating carbon trading costs: The actual carbon emissions during the operation of the accounting system; Compare actual emissions with free carbon emission allowances; If the actual emissions exceed the free allowance, the corresponding allowance will be purchased according to the preset tiered carbon price based on the amount of the excess. The greater the excess, the higher the unit carbon price. If the actual emissions do not exceed the free allowance, the remaining allowance will be sold on the carbon market to generate revenue.

[0026] The novel integrated marine energy system, featuring organic Rankine cycle waste heat recovery, can fully meet the ship's mechanical, electrical, thermal, and cooling energy needs during navigation through coordinated operation of various devices, ensuring the system's normal operation. Unlike traditional marine integrated energy systems, the core advantage of this new system lies in its efficient and safe recovery of low-grade waste heat collected by the waste heat boiler using an organic Rankine cycle, converting it into additional electricity output. During operation, the ship's mechanical propulsion needs are primarily met by the dual-fuel engine and shaft motor (acting as a motor or auxiliary propulsion), while the electrical needs are jointly supplied by the dual-fuel generator set, fuel cell, lithium battery, shaft motor, and organic Rankine cycle. The electricity generated by the organic Rankine cycle prioritizes the ship's electrical loads, electric chiller, and heat pump. Any shortfall is compensated by the lithium battery discharge; the dual-fuel generator is activated only when the lithium battery is depleted, and if the dual-fuel generator is still insufficient, the fuel cell is then activated. Any surplus electricity from the organic Rankine cycle is stored in the lithium battery. Cooling and heating needs are supplied by the electric chiller and heat pump, respectively. The Organic Rankine Cycle, as an indirect waste heat recovery solution for ship exhaust gases, first utilizes the waste heat from the ship's main engine and auxiliary engines to drive a boiler to generate high-temperature steam. This steam then serves as a secondary heat source, entering the evaporator of the Organic Rankine Cycle system to heat the working fluid, while seawater acts as the cooling medium. Through various devices, the cycle is regenerated, continuously converting waste heat into usable electrical energy, reducing the power output of other electrical equipment, and improving energy efficiency and economy.

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] In one embodiment, refer to Figure 1 As shown, this embodiment uses an organic Rankine cycle to further recover and utilize the exhaust gas generated during ship operation through a waste heat boiler to generate electricity, thereby improving energy utilization efficiency. The main components and energy flow directions of the novel integrated ship energy system with organic Rankine cycle waste heat recovery provided in this embodiment include a dual-fuel engine 1, a dual-fuel generator set 2, a fuel cell 3, a waste heat boiler 4, a shaft-driven motor 5, a lithium battery 6, an electric chiller 7, a heat pump 8, an evaporator 9, an expander 10, a generator 11, a condenser 12, a working fluid pump 13, and a carbon capture device 14, as well as the mechanical load 15, electrical load 16, thermal load 17, and cooling load 18 load requirements during ship operation, and other accessories.

[0029] In operation, the novel integrated marine energy system first generates mechanical power through the combustion of marine light diesel oil (MGO) and liquefied natural gas (LNG). During operation, the system uses LNG as the main fuel, which is directly injected into the cylinder after being pressurized and vaporized. Simultaneously, a pre-combustion chamber design or a high-pressure ignition device is used to ignite the premixed LNG-air mixture. The engine can flexibly switch to pure MGO mode (high-pressure direct injection compression ignition) or achieve arbitrary ratio mixing and combustion of LNG and MGO according to operating conditions. The output energy is mainly used to meet the mechanical load 15 of the ship. When a failure occurs, the main engine shuts down, and the shaft motor 5 is used for electric motors and ship auxiliary machinery. The dual-fuel generator 2 and fuel cell 3 provide propulsion power to meet the mechanical load 15. The shaft motor 5 provides 25% of the auxiliary machinery operating power. When the load rate of the dual-fuel engine 1 is lower than the minimum operating load rate, the shaft motor 5 is used to enhance propulsion power and work together with the dual-fuel engine 1 to meet the mechanical load 15. Secondly, the dual-fuel generator sets 2, fuel cell 3, lithium battery 6, and organic Rankine cycle (evaporator 9, expander 10, generator 11, condenser 12, working fluid pump 13) also have a portion of the mechanical energy converted into electrical energy by shaft-driven motor 5 to meet the electrical load 16 demand. The electrical energy converted by shaft-driven motor 5 accounts for 15% of the operation of dual-fuel engine 1. In the organic Rankine cycle (evaporator 9, expander 10, generator 11, condenser 12, working fluid pump 13) subsystem, the liquid R365mfc is first pressurized by working fluid pump 13 and enters evaporator 9, where it absorbs the heat energy released by the steam and becomes a high-temperature and high-pressure gas. Then, the gaseous working fluid enters expander 10 to do work, driving generator 11 to output electrical energy. Next, the low-pressure gaseous working fluid discharged from expander 10 enters condenser 12 and condenses into liquid under the cooling effect of seawater. Finally, the liquid working fluid enters storage tank and is repressurized by working fluid pump 13, forming a closed loop cycle. If the electricity generated by the organic Rankine cycle subsystem and the shaft motor 5 is insufficient to meet the total power demand (ship's electrical load, electric cooling, and electric heating), the surplus power is provided by the dual-fuel generator set 2. The dual-fuel generator set 2 generates electricity through the combustion of MGO and LNG fuels. This generator set uses vaporized LNG as the main fuel, premixed with air before entering the cylinder; simultaneously, a small amount of MGO is injected through a high-pressure injector as ignition fuel, utilizing the compression ignition characteristics of MGO to ignite the entire gas mixture, achieving efficient combustion. The system can flexibly switch between dual-fuel mode (LNG as the main fuel + MGO ignition) and pure MGO mode. If the dual-fuel generator set 2 still cannot meet the demand, the lithium battery 6 is used to supplement the supply. When the lithium battery 6 reaches its minimum capacity, the fuel cell 3 is then started. If there is still surplus power after the organic Rankine cycle (evaporator 9, expander 10, generator 11, condenser 12, working fluid pump 13) meets the total power demand, the excess power is stored in the lithium battery 6. Finally, the heat load 17 and the cooling load 18 are satisfied by the electric chiller 7 and the heat pump 8, respectively.Waste heat boiler 4 collects waste heat from the ship's main engine (dual-fuel engine 1) and auxiliary engines (dual-fuel generator set 2, fuel cell 3) to drive boiler 4 to generate high-temperature steam. This steam serves as a secondary heat source and enters the evaporator 9 of the organic Rankine system (evaporator 9, expander 10, generator 11, condenser 12, working fluid pump 13) to heat the working fluid.

[0030] The dual-fuel engine converts the chemical energy of fuel into mechanical energy through combustion, providing the mechanical power required for ship navigation. It can also be connected to a shaft-driven motor to convert mechanical energy into electrical energy, supplementing the ship's total electrical energy needs.

[0031] The dual-fuel generator set converts the chemical energy of fuel into electrical energy through combustion, providing the power required for ship operation and the power needed for electric chillers and heat pumps. It can also be connected to a shaft motor to convert electrical energy into mechanical energy, supplementing the mechanical power required for ship navigation.

[0032] The fuel cell is used to convert hydrogen into electrical energy when the lithium battery capacity reaches its minimum value, and together with the organic Rankine cycle power generation, shaft-driven motor, dual-fuel generator set and lithium battery, it meets the total power demand of the system.

[0033] The shaft-driven motor operates in two modes: PTI (Power Input Intake) and PTO (Power Toll Operation). PTI refers to the motor acting as a power input source in the ship's integrated energy system, typically used to assist or enhance the main propulsion system. When the ship's main engine (dual-fuel engine) load rate is below its minimum permissible load rate or when the main engine fails, the shaft-driven motor acts as an electric motor, working in conjunction with the ship's auxiliary machinery (dual-fuel generators and fuel cells) to provide the mechanical power required for navigation. PTO refers to the shaft-driven motor using power from the main engine to drive electrical systems or other equipment. In PTO mode, when the main engine is operating efficiently, the shaft-driven motor, connected to the shaft system of the main engine propulsion system, absorbs excess power and converts it into electrical energy to drive generator sets or auxiliary equipment, reducing fuel consumption of auxiliary machinery and thus improving overall energy efficiency.

[0034] The lithium battery is used to supplement power when the electricity generated by the organic Rankine cycle, shaft-driven motor, and dual-fuel generator set is insufficient to meet the total power demand, thus ensuring the normal operation of the system.

[0035] The electric refrigeration unit is used to ensure the supply of cooling energy for the ship, converting electrical energy into cooling energy and achieving the cooling effect through four main processes: compression, condensation, expansion, and evaporation.

[0036] The heat pump is used to ensure the supply of heat energy for the ship, converting electrical energy into heat energy. It is a device that can transfer heat energy from a low-temperature heat source to a high-temperature heat source. It gathers low-temperature and dispersed heat in a specific environment through absorption and compression, making it useful heat energy.

[0037] The waste heat boiler collects waste heat from the ship's main engine and auxiliary engines to drive the boiler to generate high-temperature steam. This steam serves as a secondary heat source and enters the evaporator of the organic Rankine system to heat the working fluid.

[0038] The shipboard carbon capture device employs a solution absorption method, using caustic soda solution as the absorbent. When ship exhaust gas (containing CO2) passes through the device, the caustic soda reacts with the carbon dioxide in the exhaust gas in a neutralization reaction (2NaOH + CO2 → Na2CO3 + H2O), converting gaseous CO2 into liquid or solid sodium carbonate (soda ash) which dissolves in the liquid phase. This achieves both CO2 fixation and removal. The resulting sodium carbonate solution is discharged from the system for compliant disposal (such as shore-based recovery or deep-sea discharge), ultimately significantly reducing carbon emissions from ship exhaust. The system operates continuously by consuming and replenishing caustic soda.

[0039] The mechanical, electrical, thermal, and cooling load requirements refer to the mechanical energy, electrical energy, thermal energy, and cooling energy required by the entire system during ship operation.

[0040] The described organic Rankine cycle is used for waste heat recovery during the operation of ship main engines and auxiliary engines. An indirect waste heat recovery method is selected to overcome the shortcomings of traditional organic Rankine systems that directly utilize exhaust heat sources such as engines. In traditional solutions, the evaporator located in the main engine flue directly contacts the high-temperature flue gas, leading to two major problems: firstly, increased flue gas flow resistance and elevated main engine exhaust back pressure, thus affecting engine combustion efficiency; secondly, the easy deposition of soot and corrosive components on the evaporator surface, causing carbon buildup and corrosion risks. To solve these problems, this integrated ship energy system adopts a two-stage heat conversion mechanism: firstly, the waste heat from the ship's main engine and auxiliary engines drives a boiler to generate high-temperature steam; then, this steam serves as a secondary heat source, entering the evaporator of the organic Rankine cycle system to heat the working fluid. This indirect heat transfer method maintains waste heat recovery efficiency while effectively isolating the flue gas from direct contact with the evaporator, significantly reducing the negative impact of exhaust resistance on the operation of the main engine and auxiliary engines, making it more suitable for practical applications of ship waste heat recovery. The high-temperature steam generated by the ship's waste heat boiler serves as the driving heat source, and seawater serves as the cooling medium.

[0041] Furthermore, the organic Rankine cycle includes an evaporator (9), an expander (10), a generator (11), a condenser (12), and a working fluid pump (13). First, liquid R365mfc is pressurized by the working fluid pump (13) and enters the evaporator (9), where it absorbs the heat energy released by the steam and becomes a high-temperature, high-pressure gas. Then, the gaseous working fluid enters the expander (10) to perform work, driving the generator (11) to output electrical energy. Next, the low-pressure gaseous working fluid discharged from the expander (10) enters the condenser (12), where it condenses into a liquid under the cooling effect of seawater. Finally, the liquid working fluid enters the storage tank and is repressurized by the working fluid pump (13), forming a closed-loop cycle.

[0042] Furthermore, the evaporator is the core heat-absorbing component of the organic Rankine cycle system. High-temperature steam generated from the ship's waste heat boiler serves as the heat source to heat the liquid organic working fluid R365mfc. During this process, the pressure and temperature of the working fluid increase significantly, ultimately resulting in complete evaporation and conversion into high-temperature, high-pressure (organic working fluid) vapor.

[0043] Furthermore, the expander is the core working component of the system. It receives high-temperature, high-pressure organic working fluid vapor (such as R365mfc) from the evaporator and allows it to expand adiabatically inside the expander. In this physical process, the thermal and pressure energy of the vapor is converted into mechanical energy (rotational kinetic energy of the shaft), driving the generator connected to it to rotate. After expansion, the vapor's temperature and pressure drop significantly, becoming low-pressure vapor (or a low-pressure gaseous state containing liquid).

[0044] Furthermore, the generator converts the mechanical energy output by the expander into electrical energy. It is directly connected and coupled to the expander's shaft. When the expander is driven to rotate by high-temperature, high-pressure steam, the generator rotates accordingly, outputting electrical energy through electromagnetic induction, thus achieving the ultimate goal of effectively recovering ship waste heat.

[0045] Furthermore, the condenser is the system's cooling and heat dissipation component. Utilizing cool seawater as the cooling medium, the low-pressure, low-temperature organic working fluid vapor (or gas mixed with a small amount of liquid droplets) formed after expansion and work is cooled and completely condensed into a liquid state. This process releases the latent heat of condensation of the working fluid to the seawater, allowing the working fluid to complete its state transition from a gaseous state to a saturated liquid state, preparing it for the subsequent pressurization cycle of the working fluid pump.

[0046] Furthermore, the working fluid pump provides the power for the system's circulation. It pressurizes the liquid working fluid (R365mfc) that has completed the condensation process and is at a low pressure. By increasing the pressure of the working fluid, the pump ensures that the liquid working fluid can be smoothly delivered to the evaporator, which is a key pressurization step to maintain the continuous operation of the organic Rankine cycle (the working fluid evaporates again in the evaporator to absorb heat).

[0047] In one embodiment, refer to Figure 2As shown, the main components and basic flow of the organic Rankine cycle waste heat recovery subsystem provided in this embodiment include an evaporator, an expander, a generator, a condenser, a working fluid pump, and a working fluid.

[0048] In operation, the organic Rankine cycle waste heat recovery subsystem utilizes the evaporator 9 as its core heat-absorbing component. It employs high-temperature steam generated by the ship's waste heat boiler 4 as a heat source to heat the liquid organic working fluid R365mfc. During this process, the pressure and temperature of the working fluid significantly increase, eventually leading to complete evaporation and conversion into high-temperature, high-pressure (organic working fluid) vapor. The expander 10 is the core working component of the subsystem, receiving the high-temperature, high-pressure organic working fluid vapor (such as R365mfc) from the evaporator 9 and allowing it to expand adiabatically within the expander. In this physical process, the thermal and pressure energy of the vapor is converted into mechanical energy (rotational kinetic energy of the shaft), driving the generator 11 connected to it to rotate. After expansion, the temperature and pressure of the vapor decrease significantly, becoming low-pressure vapor (or a low-pressure gaseous state containing liquid). The generator 11 converts the mechanical energy output from the expander 10 into electrical energy. It is directly connected and coupled to the shaft of the expander 10. When the expander 10 is driven to rotate by the high-temperature, high-pressure steam, the generator rotates accordingly, outputting electrical energy through electromagnetic induction, thus achieving the ultimate goal of effectively recovering the ship's waste heat. Condenser 12 is the cooling and heat dissipation component of the subsystem. It uses cool seawater as the cooling medium to cool and completely condense the low-pressure, low-temperature organic working fluid vapor (or gas mixed with a small amount of liquid droplets) formed after expansion and work into a liquid state. This process releases the latent heat of condensation of the working fluid to the seawater, allowing the working fluid to complete its transition from a gaseous state to a saturated liquid state, preparing it for the subsequent pressurization cycle of working fluid pump 13. Working fluid pump 13 pressurizes the liquid working fluid (R365mfc) that has completed the condensation process and is at a low pressure. By increasing the pressure of the working fluid, the pump ensures that the liquid working fluid can be smoothly delivered to evaporator 9, maintaining the continuous operation of the organic Rankine cycle (the working fluid evaporates again and absorbs heat in the evaporator), forming a closed-loop cycle.

[0049] In one embodiment, refer to Figure 3 As shown, the main components and basic flow of the ship's hybrid mechanical propulsion subsystem include a dual-fuel engine 1, a dual-fuel generator set 2, a fuel cell 3, a DC / AC converter 31, an AC power grid 32, a transformer 33, an AC / AC converter 34, a shaft-driven motor 5, a gearbox, and a propeller.

[0050] In operation, the ship's hybrid mechanical propulsion subsystem utilizes a dual-fuel engine 1 to generate mechanical power through the combustion of marine light diesel oil (MGO) and liquefied natural gas (LNG). LNG is the primary fuel, pressurized, vaporized, and directly injected into the cylinder. Simultaneously, a pre-combustion chamber design or a high-pressure ignition device ignites the premixed LNG-air mixture. The engine can flexibly switch to pure MGO mode (high-pressure direct injection compression ignition) or achieve arbitrary proportions of LNG and MGO mixture combustion according to operating conditions. A dual-fuel generator 2 generates AC power through the combustion of MGO and LNG. This generator uses vaporized LNG as the primary fuel, premixed with air before entering the cylinder. Simultaneously, a small amount of MGO is injected via a high-pressure injector as ignition fuel, utilizing the compression ignition characteristics of MGO to ignite the entire mixture, achieving efficient combustion. The DC power generated by the fuel cell 3 is converted to AC power via a DC / AC converter (31). The electrical energy from the dual-fuel generator 2 and fuel cell 3 is integrated into the AC power grid (32). One path drives the shaft motor 5 through an AC / AC converter (34) to output mechanical energy, while the other path supplies power to the ship's electrical load 16 via a transformer (33). Ultimately, the mechanical output of the dual-fuel engine 1 and the mechanical output of the shaft-driven motor 5 converge and are speed-regulated in the gearbox, jointly driving the propeller to propel the ship, achieving efficient hybrid propulsion through the synergy of mechanical and electric power. The hybrid mechanical propulsion mode adds a shaft-driven motor and its control device to the traditional mechanical propulsion system. Under high-speed, high-power conditions, it functions as a propulsion motor, working alongside the main engine to drive the propeller. It can also be disconnected from the main engine during main engine failure or low-load operation, operating independently as electric propulsion (PTI mode). Under low-speed, low-power conditions, the surplus power of the main engine is used as a generator (PTO mode). This reduces fuel consumption, improves ship operating efficiency, and simultaneously reduces exhaust emissions, enhancing the ship's economy and environmental friendliness.

[0051] In one embodiment, a novel method for optimizing the configuration of a ship's integrated energy system that integrates organic Rankine cycle waste heat recovery includes the following steps: To demonstrate the advantages of the novel integrated marine energy system, this embodiment conducts a comparative experiment based on a traditional integrated marine energy system without an organic Rankine cycle to verify the effectiveness of the novel integrated marine energy system and method. The optimizations performed are calculated under the technical parameters of each device, but are not limited to the rated power mentioned above. Specific technical parameter settings for each device are shown in Table 1. Specific parameters for cost calculations in this embodiment are shown in Table 2.

[0052] The integrated marine energy system without an organic Rankine cycle includes a dual-fuel engine, a dual-fuel generator set, a fuel cell, a dual-fuel waste heat boiler, a shaft-driven motor, an electric chiller, an absorption chiller, a thermal storage tank, and lithium batteries. Mechanical energy is provided by the dual-fuel engine and the shaft-driven motor, with the dual-fuel engine providing the majority of the mechanical energy and the shaft-driven motor providing 25% of the auxiliary engine's operating power. Electrical energy is provided by the dual-fuel generator set, fuel cell, and lithium batteries. The fuel cell first meets the electric cooling needs, the remainder meets the electrical load, and any shortfall is supplemented by the lithium batteries. When the lithium batteries reach their minimum capacity, the dual-fuel generator set is then activated. Thermal energy is provided by the dual-fuel boiler with waste heat recovery. Waste heat from the main engine and auxiliary engines first meets the absorption chiller's needs, the remainder meets the thermal load, and any shortfall is supplemented by the thermal storage tank. When the thermal storage tank reaches its minimum capacity, fuel is added to start the dual-fuel boiler. Cold energy is provided by the electric chiller and the absorption chiller.

[0053] Table 1 Technical parameters of each device in the system

[0054] Table 2 Economic Parameters of Each System Device

[0055] The following is a model of various equipment in a novel integrated marine energy system that integrates organic Rankine cycle waste heat recovery. The modules include partial module models of the ship's main engine, auxiliary engines, boiler, emission reduction equipment, energy efficiency equipment, and energy conversion and storage equipment.

[0056] (a) Marine main engine Fuel consumption of a dual-fuel engine:

[0057]

[0058] In the formula: , For dual-fuel engines t Fuel consumption of marine fuel oil and marine liquefied natural gas over a period of time; This is a binary variable indicating whether the dual-fuel engine is on or off (taken as 0 or 1, 0 for off, 1 for on); , Fuel consumption rates for marine fuel oil and marine liquefied natural gas for dual-fuel engines.

[0059] (ii) Marine auxiliary machinery Fuel consumption of dual-fuel generator sets:

[0060]

[0061]

[0062] In the formula: , , For dual-fuel generator sets in t Fuel consumption of marine fuel oil, marine liquefied natural gas and marine pilot oil over a period of time; This is a binary variable indicating whether the dual-fuel generator set is on or off (taken as 0 or 1, 0 for off, 1 for on); , , For dual-fuel generator sets, marine fuel oil, marine liquefied natural gas, and marine pilot oil are used. t Fuel consumption rate over a given time period.

[0063] Fuel consumption of fuel cells:

[0064] In the formula: For fuel cells in t Fuel consumption over a period of time; For the efficiency of fuel cells; Low calorific value of fuel used in fuel cells.

[0065] (iii) Boiler Fuel consumption of a dual-fuel boiler:

[0066] In the formula: For dual-fuel boilers t Fuel consumption over a period of time; For the efficiency of dual-fuel boilers; The low calorific value of the fuel consumed in a dual-fuel boiler.

[0067] (iv) Energy efficiency equipment There are two operating modes for shaft-driven generators: PTI and PTO.

[0068] (1) PTI mode

[0069] In the formula: The minimum allowable load rate for ship auxiliary machinery.

[0070] (2) PTO mode

[0071]

[0072] In the formula: The percentage of main power absorbed by the shaft-driven motor is 15%. For shaft-driven motor efficiency; The ship's continuous maximum power (MCR), also known as continuous power or rated power; For operational margin; For navigational margin.

[0073] (v) Emission reduction equipment

[0074] In the formula: CO2 emission reduction; To reduce emissions efficiency; This represents the actual CO2 emissions from a ship without considering emission reduction equipment.

[0075] (vi) Energy conversion and storage equipment Electric refrigeration unit:

[0076] Absorption chiller:

[0077] Lithium batteries:

[0078] In the formula: For the battery t Battery level at any given moment; , This refers to the battery's charge and discharge efficiency.

[0079] The calculations in this embodiment are all based on the models of the above-mentioned devices. The coordinated planning of the above-mentioned models can characterize the operating status of the system.

[0080] See Figure 4As shown, the main process of the new ship integrated energy system carbon trading mechanism is as follows. The core of this mechanism lies in establishing a cost model that connects the actual operation of ships with the carbon trading market. Its operation is based on strict carbon emission accounting: the carbon dioxide emissions during ship operation must be reviewed to be included in the maritime carbon trading system. The system first obtains a certain amount of free carbon emission allowances, and then compares the actual carbon emissions with these allowances: if the actual emissions do not exceed the free allowances, the system not only does not need to pay emission fees, but can also sell the remaining free allowances on the market to generate revenue; conversely, if the actual emissions exceed the free allowances, the excess must be offset by purchasing carbon emission allowances from the market. At this point, a tiered carbon pricing principle is introduced—the amount of allowances that the system needs to purchase is divided into multiple price ranges. The larger the purchase amount, the further down the price range it enters, and the higher the corresponding unit allowance purchase price. This tiered pricing mechanism, by progressively increasing the economic cost of excess carbon emissions, creates a powerful economic lever. It aims to significantly strengthen the constraints on high-carbon-emission behaviors and deeply explore the emission reduction potential of integrated ship energy systems in areas such as optimized operation, improved efficiency, adoption of low-carbon energy, and enhanced utilization of surplus energy. Therefore, this tiered carbon trading mechanism can effectively drive and continuously promote the transformation of integrated ship energy systems towards a cleaner, more efficient, and lower-cost low-carbon operating model, making it a key market-based tool for achieving carbon emission reduction targets in the shipping industry.

[0081] Table 3 shows the optimized configuration results of integrated organic Rankine cycle and non-organic Rankine cycle marine integrated energy systems obtained based on the above equipment model calculations. The system and method provided by this invention reduce the total cost by 10.32% compared to traditional marine integrated energy systems, demonstrating excellent economic efficiency. Although the fuel cost of the integrated organic Rankine cycle system increases by 21.88%, the initial investment and operation and maintenance costs decrease dramatically by 62.0% and 76.70%, respectively. Simultaneously, it eliminates equipment such as thermal storage tanks, significantly reducing the space occupied by ship equipment. This invention improves the system's economic efficiency and environmental friendliness, while also increasing energy utilization.

[0082] Table 3. Optimization configuration results of integrated organic Rankine cycle and non-organic Rankine cycle marine integrated energy systems

[0083] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A novel integrated marine energy system that integrates organic Rankine cycle waste heat recovery, characterized in that, include: Dual-fuel engine (1), dual-fuel generator set (2), fuel cell (3), waste heat boiler (4), shaft-driven motor (5), lithium battery (6), electric chiller (7), heat pump (8), organic Rankine cycle subsystem and carbon capture equipment (14). The organic Rankine cycle subsystem adopts an indirect heat exchange mechanism, which includes a two-stage heat conversion process: the first stage uses the waste heat from the exhaust gas of the ship's main engine and auxiliary engines to drive the boiler and generate high-temperature steam as an intermediate heat carrier; the second stage uses the high-temperature steam as a secondary heat source to flow into the evaporator of the organic Rankine cycle system, where the organic working fluid is indirectly heated and evaporated to do work. The dual-fuel engine (1) and the shaft-driven motor (5) constitute a hybrid propulsion system, which is used to work together to meet the mechanical load requirements of the ship; The electrical energy generated by the dual-fuel generator set (2), fuel cell (3), lithium battery (6), and shaft motor (5) in PTO mode, as well as the electrical energy generated by the organic Rankine cycle subsystem, are connected to the ship's power grid to collaboratively meet the ship's electrical load requirements. The electric chiller (7) and heat pump (8) are connected to the ship's electrical grid to meet the ship's cooling and heating load requirements, respectively. The waste heat boiler (4) is used to recover the waste heat from the exhaust gases emitted by the dual-fuel engine (1), the dual-fuel generator set (2) and the fuel cell (3) to generate high-temperature steam; The evaporator is connected to the waste heat boiler (4) and uses high-temperature steam as a secondary heat source to heat the organic Rankine cycle working fluid. The carbon capture device (14) is used to treat ship exhaust gas in order to reduce carbon emissions; The system is controlled through a cooperative scheduling mechanism, which is configured as follows: For power supply, the organic Rankine cycle subsystem and the shaft motor (5) generate electricity in PTO mode first; if the demand is still not met, the lithium battery (6) is discharged, the dual-fuel generator set (2) and the fuel cell (3) are activated in sequence; if the electricity generated by the organic Rankine cycle subsystem is surplus, the lithium battery (6) is charged; in this way, the coupling and cascade utilization of mechanical, electrical, thermal and cold multi-energy flows are realized, as well as the synergy of energy efficiency improvement and carbon emission control.

2. The novel integrated marine energy system with organic Rankine cycle waste heat recovery as described in claim 1, characterized in that: The organic Rankine cycle subsystem includes an evaporator (9), an expander (10), a generator (11), a condenser (12), and a working fluid pump (13) connected by pipelines; the working process is as follows: After being pressurized by the working fluid pump (13), the liquid organic working fluid enters the evaporator (9), absorbs the heat energy released by the high-temperature steam generated by the boiler, and is transformed into a high-temperature and high-pressure gaseous working fluid; The high-temperature and high-pressure gaseous working medium then enters the expander (10) to expand and do work, driving the generator (11) connected to it to generate electricity; The low-pressure gaseous working fluid discharged from the expander (10) enters the condenser (12) and condenses into a liquid under the action of the cooling medium; The liquid working fluid eventually flows back to the working fluid pump (13), completing a closed thermodynamic cycle; The organic Rankine cycle working fluid is R365mfc.

3. The novel integrated marine energy system with organic Rankine cycle waste heat recovery as described in claim 1, characterized in that: In the hybrid propulsion system, the output shaft of the dual-fuel engine (1) is coupled to the shaft-driven motor (5) through a gearbox to jointly drive the propeller; The shaft-driven motor (5) has two working modes: PTI and PTO. In PTI mode, when the dual-fuel engine (1) fails or its load rate is lower than the minimum operating load rate, the shaft motor (5) is powered by the dual-fuel generator set (2) and / or fuel cell (3) through the grid to provide propulsion power, either as an auxiliary or independent power source. In PTO mode, when the load rate of the dual-fuel engine (1) is higher than the set threshold, the shaft motor (5) acts as a generator to convert the surplus mechanical energy of the main engine into electrical energy and integrate it into the ship's power grid.

4. The novel integrated marine energy system with organic Rankine cycle waste heat recovery as described in claim 1, characterized in that: The carbon capture device (14) adopts the solution absorption method, using caustic soda solution as absorbent, which reacts with carbon dioxide in the waste gas to generate sodium carbonate solution, thereby achieving the fixation and removal of carbon dioxide.

5. The novel integrated marine energy system with organic Rankine cycle waste heat recovery as described in claim 1, characterized in that: The coordinated scheduling mechanism is further configured as follows: For mechanical load requirements, the dual-fuel engine (1) shall be given priority in meeting them; When the dual-fuel engine (1) fails or the load rate is insufficient, the shaft motor (5) intervenes in PTI mode to provide propulsion power together with the ship's auxiliary machinery.

6. The novel integrated marine energy system with organic Rankine cycle waste heat recovery as described in claim 1, characterized in that: The system integrates a tiered carbon trading mechanism, which calculates carbon trading costs based on the difference between a ship's actual carbon emissions and free allowances using a tiered pricing model. That is, the larger the amount of allowances purchased, the higher the applicable unit allowance price, thus forming an economic incentive for the system to operate in a low-carbon manner.

7. An optimized operation method for a novel ship integrated energy system as described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Collect the waste heat from the exhaust gases emitted by the dual-fuel engine (1), dual-fuel generator set (2) and fuel cell (3) through the waste heat boiler (4) to generate high-temperature steam; Step 2: Using the high-temperature steam as the heat source of the organic Rankine cycle subsystem, the organic working fluid is heated in the evaporator (9) to drive the expander (10) and generator (11) to generate electricity, converting waste heat into electrical energy; Step 3: Through a coordinated scheduling mechanism, dynamically allocate energy resources to meet the ship's mechanical load, electrical load, thermal load, and cooling load requirements.

8. The optimized operation method according to claim 7, characterized in that: The workflow of the organic Rankine cycle subsystem in step S2 is as follows: The liquid organic working fluid R365mfc is pressurized by the working fluid pump (13) and enters the evaporator (9) to absorb the heat energy of the high temperature steam and become high temperature and high pressure steam; The high-temperature and high-pressure steam enters the expander (10) to expand and do work, driving the generator (11) to output electrical energy; After performing work, the low-pressure gaseous working fluid enters the condenser (12) and is cooled and condensed into a liquid by seawater. The liquid working fluid returns to the storage tank, completing one cycle.

9. The optimized operation method according to claim 7, characterized in that: The collaborative scheduling mechanism in step 3 specifically includes: Power dispatching steps: Prioritize the use of the power generated by the organic Rankine cycle subsystem and the shaft motor (5) in PTO mode to meet the power demand of the electric load, electric chiller (7) and heat pump (8); if there is a shortage, the lithium battery (6) is discharged in sequence, the dual-fuel generator set (2) is started, and the fuel cell (3) is started to supplement the power; if there is surplus power, the lithium battery (6) is charged. Mechanical energy scheduling steps: prioritize the use of dual-fuel engine (1) to meet mechanical load requirements; when dual-fuel engine (1) fails or load rate is insufficient, start the PTI mode of shaft motor (5) to provide propulsion power together with auxiliary machine; Cooling and heating energy scheduling steps: The electric chiller (7) and heat pump (8) directly meet the cooling load and heating load requirements respectively.

10. The optimized operation method according to claim 7, characterized in that: It also includes the steps for calculating carbon trading costs: The actual carbon emissions during the operation of the accounting system; Compare actual emissions with free carbon emission allowances; If the actual emissions exceed the free allowance, the corresponding allowance will be purchased according to the preset tiered carbon price based on the amount of the excess. The greater the excess, the higher the unit carbon price. If the actual emissions do not exceed the free allowance, the remaining allowance will be sold on the carbon market to generate revenue.

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