Underwater closed circulation power generation and propulsion integrated system and working method

Abstract

The application provides an underwater closed circulation power generation and propulsion integrated system and a working method, comprising: a turbine for converting heat energy into mechanical energy; a compressor for compressing circulating working medium; an electric machine for converting mechanical energy and electric energy into each other; a regenerator for recovering waste heat; a seawater heat exchanger for discharging waste heat into seawater cooling medium; the turbine, the compressor and the electric machine are coaxially connected by a main shaft; a propeller is coaxially connected to the main shaft through a magnetic coupling; an isotope heat source working medium outlet is connected to a turbine working medium inlet, the turbine working medium outlet is connected to a working medium inlet of a heat release channel of the regenerator, a working medium outlet of the heat release channel of the regenerator is connected to a seawater heat exchanger working medium inlet, a seawater heat exchanger working medium outlet is connected to a compressor working medium inlet, a compressor working medium outlet is connected to a working medium inlet of a heat absorption channel of the regenerator, and a working medium outlet of the heat absorption channel of the regenerator is connected to a working medium inlet of the isotope heat source. The application has the advantages of high efficiency, low noise, self-power supply and the like, and is suitable for underwater equipment propulsion and power generation requirements.

Description

Technical Field

[0001] This invention belongs to the field of underwater propulsion and power generation technology, specifically relating to an integrated underwater closed-cycle power generation and propulsion system and its working method. Background Technology

[0002] Currently, underwater propulsion and power generation technologies mostly rely on traditional mechanical propulsion and external power supply, which suffer from problems such as low efficiency, high noise, and limited energy supply.

[0003] Patent document CN112049692A discloses a 10kW-class closed-loop Brayton cycle thermoelectric conversion system for space nuclear energy, applied in spacecraft propulsion. It converts thermal energy generated by an isotope heat source into electrical energy to power loads such as electric thrusters. This invention has a power output of 10kW. The working fluid loop is designed as a closed-loop Brayton cycle, with the working fluid sequentially undergoing adiabatic compression in the compressor, isobaric heating using an isotope source, adiabatic expansion in the turbine, and isobaric cooling.

[0004] However, patent document CN112049692A did not make specific optimizations for underwater applications. The integrated design for underwater propulsion requires additional configuration of motors, transmission mechanisms, overload design, etc. When used underwater, it not only increases the size and complexity of the system, but also leads to secondary energy conversion losses, reducing the overall energy consumption.

[0005] To meet its own power supply needs and reduce dependence on external energy sources, an integrated design is implemented for the underwater environment, enabling the underwater equipment to propel itself efficiently and quietly. Therefore, this invention designs an integrated underwater closed-loop power generation and propulsion system and its operating method, solving the aforementioned problems. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide an integrated underwater closed-cycle power generation and propulsion system and its operating method.

[0007] An underwater closed-cycle power generation and propulsion integrated system according to the present invention includes: an isotope heat source, a regenerator, a turbine, a compressor, a motor, a magnetic coupling, a propeller, and a seawater heat exchanger; The isotope heat source is used to provide thermal energy for the system; the turbine is used to convert thermal energy into mechanical energy; the compressor is used to compress the circulating working fluid; the motor is used to convert mechanical energy into electrical energy and vice versa; the regenerator is used to recover waste heat and transfer it to the circulating working fluid; the seawater heat exchanger is used to discharge waste heat into the seawater cooling medium; the turbine, compressor, and motor are coaxially connected by the main shaft; the propeller is coaxially connected to the main shaft through a magnetic coupling; The working fluid outlet of the isotope heat source is connected to the working fluid inlet of the turbine, the working fluid outlet of the turbine is connected to the working fluid inlet of the heat release channel of the regenerator, the working fluid outlet of the heat release channel of the regenerator is connected to the working fluid inlet of the seawater heat exchanger, the working fluid outlet of the seawater heat exchanger is connected to the working fluid inlet of the compressor, the working fluid outlet of the compressor is connected to the working fluid inlet of the heat absorption channel of the regenerator, and the working fluid outlet of the heat absorption channel of the regenerator is connected to the working fluid inlet of the isotope heat source.

[0008] Preferably, the isotope heat source, regenerator, turbine, compressor, motor, and seawater heat exchanger are sealed inside the underwater equipment; the propeller is rotatably connected to the outside of the underwater equipment; one end of the magnetic coupling is set on the main shaft, and the other end is set on the propeller shaft, with the two ends of the magnetic coupling magnetically connected at intervals.

[0009] Preferably, the isotope heat source is a plutonium-238 radioactive isotope, and the isotope heat source is encapsulated in a protective structure.

[0010] Preferably, the turbine is a radial turbine.

[0011] Preferably, the regenerator adopts a plate-fin structure.

[0012] Preferably, the seawater heat exchanger is a plate or shell-and-tube heat exchanger made of corrosion-resistant titanium alloy.

[0013] Preferably, the compressor is a centrifugal compressor.

[0014] Preferably, the motor is an integrated starter motor.

[0015] Preferably, the power load is at least one of other power-consuming systems, electrical equipment, or energy storage devices.

[0016] According to the present invention, a method for operating an integrated underwater closed-cycle power generation and propulsion system is provided, which employs an integrated underwater closed-cycle power generation and propulsion system and includes the following steps: Step S1: System Startup Phase: After the motor is initialized in the system, the battery or initial power supply first supplies power to the motor; the motor drives the rotor assembly consisting of the turbine and compressor to start rotating; when the speed reaches the preset idle speed, the system begins to establish the initial working fluid cycle; the compressor compresses the circulating working fluid in the system; the compressed working fluid flows through the regenerator and isotope heat source in sequence, while the isotope heat source continuously provides decay heat to heat the working fluid, and the heated working fluid then enters the turbine; Step S2: Self-sustaining operation and power generation stage: As the cycle is established and the isotope heat source continues to heat the working fluid, the temperature and pressure at the turbine inlet continuously increase; when the turbine's output power equals and begins to exceed the compressor's compression power consumption and system mechanical losses, the system reaches the self-sustaining point; as operation continues, the shaft power will turn positive, the external drive power supply to the motor will be cut off, and the motor will automatically switch to power generation mode. The turbine's excess mechanical energy will be converted into electrical energy through the motor and used to power the electrical load; according to the electrical load demand, the system's power generation can be adjusted by means such as adjusting the working fluid flow rate or the turbine back pressure; Step S3: Propulsion process: The high-speed rotation of the rotor assembly is transmitted to the external propeller without contact through the magnetic coupling; the magnetic coupling uses high-performance permanent magnets; the rotation of the propeller generates thrust, which propels the underwater equipment to sail.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. High Efficiency: The high efficiency of the closed Brayton cycle ensures efficient conversion of thermal energy into electrical energy. The rotor assembly design, directly connected to a centrifugal compressor and a radial turbine, reduces shaft energy loss, improves thermal-to-electrical conversion efficiency, and enhances mechanical energy output. The integrated thermoelectric-propulsion energy distribution method allows the mechanical energy output from the turbine to be directly allocated to power generation and propulsion, avoiding the secondary energy conversion losses of the traditional method of "generating electricity and then driving the propulsion motor," thus achieving cascaded energy utilization and reducing secondary conversion losses.

[0018] 2. Low noise: No noise from traditional mechanical propulsion, suitable for underwater missions requiring a quiet environment. The fully integrated power unit allows for simpler noise control via the underwater equipment housing. The highly integrated structure saves internal space, providing ample room for audio isolation. Magnetic connection to the propeller completely eliminates vibration transmission, far exceeding the performance of traditional transmission drive structures.

[0019] 3. Self-powered capability: The system achieves self-powered operation through motor generation, reducing dependence on external energy sources. Adaptive power supply under operating conditions, high stability: When the underwater propulsion load or external electrical load changes, the integrated starter motor can dynamically adjust the generator / motor mode, balancing the mechanical energy distribution of the shaft system and ensuring stable power supply to the system itself.

[0020] 4. Compact Structure: The integrated design reduces system complexity and size, facilitating miniaturized applications. Simplified shaft structure shortens the core power module length: Directly connecting the radial turbine and centrifugal compressor eliminates the coupling between them, significantly shortening the axial length of the core power module. Compact heat exchange modules improve space utilization: Employing a seawater regenerator reduces auxiliary components of conventional heat exchangers, further compressing the heat exchange module's volume and allowing it to be arranged close to the shaft, eliminating redundant piping. Integrated thermoelectric-propulsion system eliminates the need for an additional propulsion module: Integrating the thermoelectric conversion system with the underwater propulsion system's shaft eliminates the need for additional propulsion motors and transmission mechanisms, reducing the number and size of components in the entire system. Attached Figure Description

[0021] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] The diagram shows: 1. Isotope heat source; 2. Turbine; 3. Regenerator; 4. Seawater heat exchanger; 5. Compressor; 6. Electric motor; 7. Electrical load; 8. Propeller; 9. Magnetic coupling. Detailed Implementation

[0023] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0024] like Figure 1 As shown, an underwater closed-cycle power generation and propulsion integrated system includes: an isotope heat source 1, a regenerator 3, a turbine 2, a compressor 5, a motor 6, a magnetic coupling 9, a propeller 8, and a seawater heat exchanger 4.

[0025] The isotope heat source 1 is used to provide thermal energy for the system; the turbine 2 is used to convert thermal energy into mechanical energy; the compressor 5 is used to compress the circulating working fluid; the motor 6 is used to convert mechanical energy into electrical energy; the regenerator 3 is used to recover waste heat and transfer it to the circulating working fluid; the seawater heat exchanger 4 is used to discharge waste heat into the seawater cooling medium; the turbine 2, compressor 5, and motor 6 are coaxially connected by the main shaft; the propeller 8 is coaxially connected to the main shaft through a magnetic coupling 9.

[0026] The working fluid outlet of isotope heat source 1 is connected to the working fluid inlet of turbine 2. The working fluid outlet of turbine 2 is connected to the working fluid inlet of the heat release channel of regenerator 3. The working fluid outlet of the heat release channel of regenerator 3 is connected to the working fluid inlet of seawater heat exchanger 4. The working fluid outlet of seawater heat exchanger 4 is connected to the working fluid inlet of compressor 5. The working fluid outlet of compressor 5 is connected to the working fluid inlet of the heat absorption channel of regenerator 3. The working fluid outlet of the heat absorption channel of regenerator 3 is connected to the working fluid inlet of isotope heat source 1.

[0027] The working principle of this application is as follows: Isotope heat source 1 heats the working fluid to form a high-temperature, high-pressure working fluid, which enters turbine 2 to expand and do work, driving turbine 2 to rotate; turbine 2 coaxially drives compressor 5 and integrated motor 6 to rotate, and drives propeller 8 to generate propulsion force through magnetic coupling 9, while motor 6 outputs electrical energy to supply power load 7. The medium-temperature exhaust gas after turbine 2 has done work enters the heat release channel of regenerator 3 to recover heat; the working fluid after heat release enters seawater heat exchanger 4 for further cooling, and then returns to compressor 5. Compressor 5 compresses and pressurizes the low-temperature, low-pressure working fluid, and sends it to the heat absorption channel of regenerator 3 to absorb the heat transferred from the heat release channel, thus achieving preheating; the preheated working fluid re-enters isotope heat source 1 to be heated, enabling the system to complete the operation based on a closed Brayton cycle.

[0028] The integrated design reduces system complexity and size, facilitating miniaturized applications. The simplified shaft structure shortens the core power module length: directly connecting the radial turbine 2 to the centrifugal compressor 5 eliminates the coupling between them, significantly reducing the axial length of the core power module. The compact heat exchange module improves space utilization: employing a seawater regenerator 3 reduces auxiliary components of conventional heat exchangers, further compressing the heat exchange module's volume and allowing it to be arranged close to the shaft, eliminating redundant piping. Integrated thermoelectric-propulsion system eliminates the need for an additional propulsion module: integrating the thermoelectric conversion system with the underwater propulsion system's shaft eliminates the need for additional propulsion motors and transmission mechanisms, reducing the number and size of components in the entire system.

[0029] Specifically, the isotope heat source 1, regenerator 3, turbine 2, compressor 5, motor 6, and seawater heat exchanger 4 are sealed inside the underwater equipment, with no external power supply wiring. This reduces the number of external sealing interfaces of the underwater equipment, significantly lowering the risk of failure. The propeller 8 is rotatably connected to the outside of the underwater equipment and is used to generate underwater thrust to propel the equipment. One end of the magnetic coupling 9 is set on the main shaft, and the other end is set on the propeller 8 shaft. The two ends of the magnetic coupling 9 are magnetically connected at intervals. The magnetic coupling 9 directly converts the kinetic energy of the shaft system during the circulation process into propulsion power, reducing underwater interfaces and improving system reliability. This avoids the problem in existing technologies where the electrical energy generated during the circulation process is converted into propulsion power a second time, increasing the number of power supply interfaces and corresponding auxiliary components, which increases the complexity of the entire system and the risk of failure.

[0030] In one embodiment, the isotope heat source 1 is located at the front end of the system and uses a radioactive isotope such as plutonium-238. Its decay process releases stable and persistent heat. The isotope heat source 1 is encapsulated in a multi-layer protective structure to ensure safety and reliability, and to provide a high-temperature and stable input heat load for the core thermodynamic cycle.

[0031] In one embodiment, turbine 2 is a centripetal turbine that converts thermal energy and pressure potential energy into high-speed rotational mechanical energy of the rotor. Its compact structure and high-speed characteristics are very suitable for direct connection with compressor 5 of this system, forming a highly efficient energy conversion core.

[0032] The rotor assembly, featuring a direct-drive configuration of a radial turbine (2 units) and a centrifugal compressor (5 units), reduces shaft energy loss, improves thermo-electric conversion efficiency, and enhances mechanical energy output. The integrated thermoelectric-propulsion energy distribution method allows the mechanical energy output from turbine 2 to be directly allocated to power generation and propulsion, avoiding the secondary energy conversion losses of the traditional method of "generating electricity and then driving the propulsion motor." This achieves cascaded energy utilization and reduces secondary conversion losses. It produces no noise like traditional mechanical propulsion, making it suitable for underwater missions requiring a quiet environment.

[0033] In one embodiment, the regenerator 3 adopts a high-efficiency compact plate-fin structure, which uses the medium-temperature exhaust gas at the working fluid outlet of the turbine 2 to preheat the low-temperature working fluid at the working fluid outlet of the compressor 5. This process recovers some of the waste heat that should have been discharged into the seawater, reduces the load requirements of the isotope heat source 1, and improves the efficiency of the entire thermal cycle.

[0034] In one embodiment, the seawater heat exchanger 4 serves as the circulating cold source and can be a plate or shell-and-tube heat exchanger made of corrosion-resistant titanium alloy. The circulating working medium transfers waste heat to the low-temperature seawater, completing the circulation process. Compared to existing technologies that require an independent cold source to control the cooler's performance, this design eliminates the need for auxiliary components to independently control the cooling medium, resulting in a more compact overall structure. In one embodiment, the compressor 5 is a centrifugal compressor, which compresses the gaseous circulating working fluid through the centrifugal force generated by the high-speed rotation of the rotor, increasing its pressure and temperature to prepare it for entry into the regenerator 3 and isotope heat source 1 for heating. The compressor 5 and the turbine 2 are connected by a main shaft to form a rotor assembly, realizing efficient energy transfer and conversion under high-speed operating conditions.

[0035] In one embodiment, the motor 6 is an integrated starter motor. When the system starts, it drives the rotor assembly to rotate as a motor, establishing the flow and pressure of the circulating working fluid. After the system stabilizes, when the output shaft power of the turbine 2 is positive, the motor 6 switches to power generation mode, converting mechanical energy into electrical energy to supply the power load 7 of the underwater equipment.

[0036] In one embodiment, the power load 7 is other power-consuming systems, electrical equipment, or energy storage devices outside this system, used to utilize or store the excess electrical energy converted by this system, and does not require additional external power supply during startup.

[0037] The system achieves self-powered operation through generator 6, reducing reliance on external energy sources. It features adaptive power supply for various operating conditions, ensuring high stability: when the underwater propulsion load or external electrical load changes, the integrated generator 6 can dynamically adjust the generator / motor mode, balancing the distribution of mechanical energy in the shaft system and ensuring stable power supply to the system itself.

[0038] In one embodiment, the propeller 8 is directly driven by the magnetic coupling 9, and the blades are hydrodynamically optimized to have high propulsion efficiency and low cavitation characteristics at a specific speed, ensuring that hydrodynamic noise is reduced while generating effective thrust.

[0039] In one embodiment, the magnetic coupling 9 employs permanent magnet coupling technology to achieve contactless torque transmission, coupling the rotor assembly sealed inside the system to the propeller shaft 8 underwater. The magnetic coupling 9, through its non-contact design, completely solves the leakage and wear problems of the dynamic seal, effectively isolates the internal circulation system from the external seawater environment, has a certain torque overload protection capability, and improves the system's reliability and lifespan.

[0040] With its fully integrated power components, noise can be controlled more easily using the underwater equipment housing. At the same time, the highly integrated structure saves internal space and provides more room for the arrangement of audio isolation for underwater equipment. The magnetic connection of the propeller 8 completely eliminates the transmission of vibration, far exceeding that of a transmission drive structure.

[0041] This application also provides a method for operating an integrated underwater closed-cycle power generation and propulsion system, which employs an integrated underwater closed-cycle power generation and propulsion system, and includes the following steps: Step S1: System Startup Phase: After the motor 6 is initialized, it is initially powered by the battery or initial power supply, enabling it to operate as a motor. The motor 6 drives the rotor assembly consisting of the turbine 2 and compressor 5 to begin rotating. When the speed reaches the preset idle speed (e.g., 20%-30% of the rated speed), the system begins to establish an initial working fluid cycle. At this time, the compressor 5 begins to compress the circulating working fluid in the system, and the pressure and temperature of the working fluid initially increase. The compressed working fluid flows sequentially through the regenerator 3 and the isotope heat source 1, while the isotope heat source 1 continuously provides decay heat to heat the working fluid. The heated working fluid then enters the turbine 2. During the startup phase, the power generated by the turbine 2 is insufficient to drive the compressor 5, and the power for the entire rotor assembly is still provided by the motor 6.

[0042] Step S2: Self-sustaining Operation and Power Generation Stage: As the cycle is established and isotope heat source 1 continues to heat, the temperature and pressure of the working fluid at the turbine 2 inlet continuously increase, and its output power also increases accordingly. When the output power of turbine 2 equals and begins to exceed the compression power consumption of compressor 5 and system mechanical losses, the system reaches the self-sustaining point. Continuing operation, the shaft power will turn positive, the external drive power supply to motor 6 will be cut off, and motor 6 will automatically switch to power generation mode. The excess mechanical energy of turbine 2 will be converted into electrical energy through motor 6 and used to power the electrical load 7. The medium-temperature, medium-pressure working fluid, after completing its work, will be discharged from the turbine 2 outlet and first enter the regenerator 3, transferring the remaining waste heat to the low-temperature working fluid that just exited compressor 5, achieving heat recovery. Subsequently, the working fluid will continue to flow to the seawater heat exchanger 4, releasing the final waste heat to the seawater cooling medium. The working fluid temperature and pressure will drop to the lowest point of the cycle, and then it will be drawn back into compressor 5, completing the entire thermodynamic cycle. The system's power generation can be adjusted according to the needs of the electrical load 7, such as by adjusting the working fluid flow rate or the back pressure of turbine 2.

[0043] Step S3: Propulsion Process: The high-speed rotation of the rotor assembly is transmitted to the external propeller 8 without contact via the magnetic coupling 9. The magnetic coupling 9 uses high-performance permanent magnets (such as neodymium iron boron), which not only achieves high transmission efficiency but also completely solves the problems of working fluid leakage and wear at the dynamic seal. The rotation of the propeller 8 generates thrust, propelling the underwater equipment.

[0044] This application enables efficient conversion of thermal energy into electrical energy and achieves efficient propulsion of underwater equipment through a propulsion device. The invention directly connects the shaft system of the thermoelectric conversion system to the propeller 8 via a magnetic coupling 9. This allows the mechanical energy output from the turbine 2 to simultaneously drive power generation and underwater propulsion, achieving an integrated output of "thermal energy → mechanical energy → electrical energy + propulsion power." This eliminates the need for an additional propulsion system, removes losses from secondary energy conversion, and enhances integration while reducing space occupation. Furthermore, the invention proposes a magnetic coupling 9 to achieve contactless torque transmission between the shaft system and the propeller 8, effectively isolating the internal closed-loop system from the external water environment, while also providing torque overload protection, significantly improving the reliability of underwater propulsion.

[0045] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0046] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An integrated underwater closed-cycle power generation and propulsion system, characterized in that, include: Isotope heat sources, regenerators, turbines, compressors, motors, magnetic couplings, propellers, and seawater heat exchangers; The isotope heat source is used to provide thermal energy for the system; The turbine is used to convert thermal energy into mechanical energy; the compressor is used to compress the circulating working fluid; the motor is used to convert mechanical energy and electrical energy into each other; the regenerator is used to recover waste heat and transfer it to the circulating working fluid; the seawater heat exchanger is used to discharge waste heat into the seawater cooling medium; the turbine, compressor, and motor are coaxially connected by the main shaft; the propeller is coaxially connected to the main shaft through a magnetic coupling. The working fluid outlet of the isotope heat source is connected to the working fluid inlet of the turbine, the working fluid outlet of the turbine is connected to the working fluid inlet of the heat release channel of the regenerator, the working fluid outlet of the heat release channel of the regenerator is connected to the working fluid inlet of the seawater heat exchanger, the working fluid outlet of the seawater heat exchanger is connected to the working fluid inlet of the compressor, the working fluid outlet of the compressor is connected to the working fluid inlet of the heat absorption channel of the regenerator, and the working fluid outlet of the heat absorption channel of the regenerator is connected to the working fluid inlet of the isotope heat source.

2. The underwater closed-cycle power generation and propulsion integrated system according to claim 1, characterized in that, The isotope heat source, regenerator, turbine, compressor, motor, and seawater heat exchanger are sealed inside the underwater equipment; the propeller is rotatably connected to the outside of the underwater equipment; one end of the magnetic coupling is set on the main shaft, and the other end is set on the propeller shaft, with the two ends of the magnetic coupling magnetically connected at intervals.

3. The underwater closed-cycle power generation and propulsion integrated system according to claim 2, characterized in that, The isotope heat source uses plutonium-238 radioactive isotope, and the isotope heat source is encapsulated in a protective structure.

4. The underwater closed-cycle power generation and propulsion integrated system according to claim 2, characterized in that, The turbine is a centripetal turbine.

5. The underwater closed-cycle power generation and propulsion integrated system according to claim 2, characterized in that, The regenerator adopts a plate-fin structure.

6. The underwater closed-cycle power generation and propulsion integrated system according to claim 2, characterized in that, The seawater heat exchanger is a plate or shell-and-tube heat exchanger made of corrosion-resistant titanium alloy.

7. The underwater closed-cycle power generation and propulsion integrated system according to claim 2, characterized in that, The compressor is a centrifugal compressor.

8. The underwater closed-cycle power generation and propulsion integrated system according to claim 2, characterized in that, The motor is an integrated starter motor.

9. The underwater closed-cycle power generation and propulsion integrated system according to claim 2, characterized in that, The power load is at least one of other power-consuming systems, electrical equipment, or energy storage devices.

10. A method for operating an underwater closed-cycle power generation and propulsion integrated system, employing the underwater closed-cycle power generation and propulsion integrated system of any one of claims 1-9, comprising the following steps: Step S1: System startup phase: After the motor is initialized in the system, it is first powered by the battery or initial power supply. The motor drives the rotor assembly, which consists of a turbine and a compressor, to start rotating. When the speed reaches the preset idle speed, the system begins to establish an initial working fluid cycle. The compressor compresses the circulating working fluid in the system. The compressed working fluid flows through the regenerator and the isotope heat source in sequence. At the same time, the isotope heat source continuously provides decay heat to heat the working fluid. The heated working fluid then enters the turbine. Step S2: Self-sustaining operation and power generation stage: As the cycle is established and the isotope heat source continues to heat the working fluid, the temperature and pressure at the turbine inlet continuously increase; when the turbine's output power equals and begins to exceed the compressor's compression power consumption and system mechanical losses, the system reaches the self-sustaining point; as operation continues, the shaft power will turn positive, the external drive power supply to the motor will be cut off, and the motor will automatically switch to power generation mode. The turbine's excess mechanical energy will be converted into electrical energy through the motor and used to power the electrical load; according to the electrical load demand, the system's power generation can be adjusted by means such as adjusting the working fluid flow rate or the turbine back pressure; Step S3: Propulsion process: The high-speed rotation of the rotor assembly is transmitted to the external propeller without contact through the magnetic coupling; the magnetic coupling uses high-performance permanent magnets; the rotation of the propeller generates thrust, which propels the underwater equipment to sail.

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