A submersible power system based on solid oxide fuel cells

Abstract

The present invention proposes a submersible power system based on solid oxide fuel cells, which is configured on the submersible and located in the insulation layer of its casing, and includes a solid oxide fuel cell system, an exhaust gas heat recovery loop, a cooling circulation loop, a power generation module and a power control system. The solid oxide fuel cell system includes a solid oxide fuel cell with a heat exchange structure, a fuel supply device and an oxygen supply device. A burner is provided on the exhaust gas heat recovery loop, and the cooling circulation loop outputs the heat energy of the solid oxide fuel cell through the heat exchange structure. The power generation module includes a Stirling engine, a heat recovery loop and a generator. The power control system includes a temperature control system, a first temperature sensor, a drive control module and an electric motor. The submersible power system of the present invention utilizes the exhaust gas heat recovery loop and the cooling circulation loop to recover the radiant heat energy and exhaust gas heat energy of the SOFC, and the Stirling engine on the heat recovery loop does work to supplement the electric energy, thereby improving the SOFC fuel utilization rate.

Description

Technical Field

[0001] The present invention belongs to the technical field of underwater vehicles, and in particular relates to a submersible power system based on solid oxide fuel cells. Background Art

[0002] The requirements for the power of a submersible are a long underwater endurance, power that meets the requirements and operational safety. The power systems used by existing conventional submersibles when diving underwater include closed diesel engines, Stirling engines, proton exchange membrane hydrogen fuel cells, power batteries, solid oxide fuel cells (SOFC), etc. Among them, the closed diesel engine has the disadvantages of high working noise and poor underwater quietness; the Stirling engine has the disadvantages of low power density and slow speed of the submersible; the proton exchange membrane hydrogen fuel cell has the risk of hydrogen leakage and poor safety; the power battery stores too little energy, the submersible speed is too slow, and the cruising range is too short; SOFC has the characteristics of high power generation efficiency, no mechanical moving parts (long service life, low noise), strong fuel adaptability, and high safety performance, and is one of the more promising power sources for the power system of the submersible; the solid oxide fuel cell is a high-temperature fuel cell with an operating temperature range of 650-800 degrees Celsius. The energy utilization efficiency is higher than that of the proton exchange membrane hydrogen fuel cell, but due to the high thermal radiation and exhaust emission temperature, the energy loss problem of the solid oxide fuel cell is also more serious;

[0003] The existing technology usually uses a burner to burn the exhaust gas and then recovers the exhaust gas energy of the solid oxide fuel cell through a heat exchange system, and uses the recovered heat energy to preheat or treat the fuel. This technology only recovers the fuel and oxygen source that are not consumed in the reaction, and does not involve the recovery of radiation energy and exhaust gas heat energy;

[0004] The existing technology for better heat recovery is Boeing's patent "CN201510379060.3 Heat recovery and temperature control for underwater vehicles using fuel cells". This patent controls the temperature of SOFC by increasing the speed of the cathode blower to change the cathode gas flow rate and changing the area of ​​the variable heat sink of the Stirling engine, and brings the heat to the Stirling engine for power generation. Due to the poor thermal conductivity of the gas, the method of increasing the gas flow rate will consume a large amount of electricity generated by the solid oxide fuel cell, and the overall energy utilization efficiency of the system is not high; furthermore, it adopts the method of surrounding the S The SOFC is cooled by taking away the heat in the insulation box outside the OFC, which aggravates the temperature difference between the outer surface and the inside of the SOFC, further increasing the temperature gradient and thermal stress inside the SOFC. The stress inside the SOFC is one of the main reasons for premature structural damage and reduced service life. In addition, the heat transfer medium in the heat exchanger in the cooling circuit between the insulation box of the SOFC and the Stirling engine in this patent is water. Since the temperature of the SOFC is as high as 650-800 degrees Celsius, the temperature difference between the SOFC and the cooling water is large, the energy transfer efficiency is low, and the thermal energy quality brought to the Stirling engine is low. Summary of the invention

[0005] The object of the present invention is to provide a submersible power system based on solid oxide fuel cells to solve the problems raised in the above background technology.

[0006] The technical solution of the present invention is achieved in this way:

[0007] A submersible power system based on a solid oxide fuel cell is configured on the submersible and located in the heat insulation layer of its casing, comprising:

[0008] A solid oxide fuel cell system, comprising a solid oxide fuel cell, a fuel supply device for controlling the delivery of a fuel source, and an oxygen supply device for controlling the delivery of an oxygen source, wherein the solid oxide fuel cell comprises an anode electrode and a cathode electrode, and a heat exchange structure is also provided therein;

[0009] An exhaust heat recovery circuit, on which a burner is provided, is used to collect the exhaust gas from the anode electrode and transport it to the fuel supply device, perform heat exchange to recover heat energy, and then transport it to the burner; and is used to collect the exhaust gas from the cathode electrode and transport it to the oxygen supply device, perform heat exchange to recover heat energy, and then transport it to the burner;

[0010] A cooling circulation loop is formed by sequentially connecting a solid oxide fuel cell, a heat dissipation circulation pump and a first heat exchanger, and outputs heat energy of the solid oxide fuel cell through a heat exchange structure;

[0011] A power generation module, comprising a Stirling engine, a heat recovery loop coupled to a hot end of the Stirling engine, and a generator connected to a power output shaft of the Stirling engine, wherein a cold end of the Stirling engine is coupled to a casing outside a heat insulation layer, and the heat recovery loop is driven to circulate by a heat exchange circulation pump, and a first heat exchanger and a burner are sequentially coupled in series to the hot end of the Stirling engine; and,

[0012] The electric power control system includes a temperature control system, a first temperature sensor arranged on a solid oxide fuel cell, a drive control module and an electric motor. The solid oxide fuel cell and the generator are connected in parallel at one level, and the electric power is transmitted to the electric motor after being inverted and converted by the drive control module. The temperature control system receives the temperature signal of the first temperature sensor and sends a control signal to the heat dissipation circulation pump and the heat exchange circulation pump.

[0013] Preferably, the heat exchange medium in the cooling circulation loop and the heat recovery loop is molten salt, and a second temperature sensor and a heater are sequentially arranged on the cooling circulation loop, located at the rear end of the first heat exchanger. The temperature control system receives the temperature signals of the first temperature sensor and the second temperature sensor, processes and sends control signals to the heater.

[0014] More preferably, the power control system further comprises a battery, the battery and the solid oxide fuel cell are connected in parallel at two levels, and the drive control module sends a control signal to start and stop the battery power transmission line.

[0015] Further preferably, it also includes an electric power supplement circuit, including a fuel branch connecting the fuel source and the burner and an oxygen branch connecting the oxygen source and the burner, and both the fuel branch and the oxygen branch are provided with a control device for controlling the gas flow, and the control device receives a control signal sent by the execution drive control module.

[0016] Further preferably, it also includes a second heat exchanger, which utilizes the heat energy recovery circuit to secondary recover the exhaust gas heat energy of the exhaust gas heat recovery circuit. In the heat energy recovery circuit, the second heat exchanger is located at the front end of the first heat exchanger, and in the exhaust gas heat recovery circuit, the second heat exchanger is located at the front end of the burner.

[0017] Further preferably, the solid oxide fuel cell is a layered stack structure, including a battery cell layer consisting of a cathode electrode and an anode electrode of a plate-like structure and an electrolyte layer located between the cathode electrode and the anode electrode, multiple battery cell layers are stacked in sequence, and the heat exchange structure is a heat exchange layer plate sandwiched between the battery cell layers.

[0018] Further preferably, the first temperature sensor is disposed on the exhaust gas outlet of the cathode electrode, or the first temperature sensor is disposed on the exhaust gas outlet of the anode electrode.

[0019] Further preferably, the molten salt is a binary or ternary inorganic molten salt with an operating temperature of 350°C-700°C.

[0020] Compared with the prior art, the submersible power system of the present invention has the following beneficial effects:

[0021] 1. Utilize the exhaust gas heat recovery loop and cooling cycle loop to recover the radiation heat energy and exhaust gas heat energy of SOFC, and transmit it to the Stirling engine on the heat recovery loop to work and supplement the system power, thus reducing heat energy loss and fully improving the SOFC fuel utilization rate;

[0022] 2. The cooling circulation loop uses molten salt to flow through the internal heat exchange plate of SOFC to remove the heat of SOFC. The heat dissipation is uniform, and the molten salt temperature is high, which is close to the working temperature of SOFC. No large temperature gradient will be generated during the cooling process of SOFC, which reduces the thermal stress of SOFC and increases the service life of SOFC. In addition, the heat capacity of molten salt is large, and the molten salt system can meet the heat dissipation requirements of SOFC with a smaller flow rate. The power of the circulation pump is low, which saves the electricity generated by SOFC and has a higher overall energy efficiency.

[0023] 3. The power supplement circuit utilizes the burner in the power system and further expands it as a backup power source, which can simultaneously meet the power requirements of lower rated power operation and function expansion under common working conditions of the submersible;

[0024] 4. The exhaust gas emitted by SOFC is utilized in three stages, which improves the fuel utilization rate of SOFC. The recovered heat energy is transferred to the Stirling engine, further improving the fuel utilization rate of SOFC. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A schematic diagram of the structure of a power system according to an embodiment of the present invention;

[0027] Figure 2 A schematic structural diagram of a power system according to another embodiment of the present invention;

[0028] Figure 3 A schematic diagram of the structure of a power system of the best embodiment disclosed in the present invention;

[0029] Figure 4 It is a schematic diagram of the structure of the SOFC disclosed in the present invention;

[0030] Figure 5It is a schematic diagram of the battery unit layer stacking structure of the SOFC disclosed in the present invention.

[0031] In the figure: 1. fuel source; 2. oxygen source; 3. fuel supply device; 4. oxygen supply device; 5. SOFC; 51. battery unit layer; 511. cathode gas channel; 512. anode gas channel; 513. cathode electrode; 514. electrolyte layer; 515. anode electrode; 52. heat exchange layer plate; 521. molten salt flow channel; 522. confluence; 523. electrode gas channel hole; 53. molten salt transport main pipe; 6. first heat exchanger; 7. second heat exchanger; 8. burner; 9. Stirling engine; 10. heat dissipation circulation pump; 11. heater; 12. battery; 13. generator; 14. drive control module; 15. motor; 16. control device; 17. heat exchange circulation pump. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The submersible needs to run in the water for a long period of time and complete uniform speed movement, accelerated movement, turning, diving and other related actions underwater according to the route. Due to the weight and volume restrictions of the submersible, it is impossible to carry a large power source. In order to meet the requirements of the submersible for a longer cruising range, power and efficiency, a hybrid power structure with a solid oxide fuel cell 5 (hereinafter referred to as SOFC5) as the main and a Stirling engine 9 as the auxiliary is the basic structure of the power system of the present invention. SOFC5 is a high-temperature fuel cell with an operating temperature range of 650-800°C and high energy utilization efficiency. Of course, its ability to radiate heat energy outward is stronger and the exhaust gas discharged also carries a higher temperature. Therefore, the Stirling engine 9 can use this heat energy to generate electricity, consume the excess heat energy of SOFC5 in time, and further improve the energy utilization efficiency of the power system. The entire power system is configured in the heat insulation layer of the submersible casing to prevent heat radiation loss.

[0034] The fuel source 1 of the SOFC 5 includes but is not limited to hydrogen, methanol, ammonia, and diesel, and the oxygen source 2 includes but is not limited to liquid oxygen, gaseous oxygen, and air, and the SOFC 5 adopts a layered stack structure, that is, a battery unit layer 51 composed of a cathode electrode 513 and an anode electrode 515 of a plate-like structure and an electrolyte layer 514 located between the cathode electrode 513 and the anode electrode 515, and at least 10 layers of battery unit layers 51 are stacked in sequence to form a battery stack;

[0035] like Figure 1 The structure of the submersible power system is shown in one of the exemplary embodiments. In this embodiment, the solid oxide fuel cell system as the main power source includes SOFC5, a fuel supply device 3 for controlling the delivery of the fuel source 1, and an oxygen supply device 4 for controlling the delivery of the oxygen source 2. The fuel supply device 3 and the oxygen supply device 4 are selected and configured according to the fuel type of the fuel source 1 and the type of the oxygen source 2, including but not limited to setting corresponding existing components to control the opening and closing, decompression control, flow control and clean treatment of the fuel source 1 and the oxygen source 2, but a heat exchange structure should be set on the peripheral wall of the flow channel of the fuel and oxygen-containing gas to recover the heat energy of the exhaust gas to preheat the fuel and the oxygen-containing gas, reduce the temperature fluctuation of the SOFC5 electrode, and help maintain the efficient power generation state within the optimal temperature of the SOFC5. In order to prevent the SOFC5 from overheating, a heat exchange layer plate 52 is sandwiched between every two layers of battery unit layers 51, such as Figure 5 In the stacked structure shown, the heat exchange layer plate 52 is clamped and sealed by the anode electrode 515 and the cathode electrode 513 on both sides, and has molten salt flow channels 521 on both sides. The molten salt flow channels 521 are connected to the molten salt transport main pipe 53 fixed outside the SOFC5 through the confluence port 522. The heat exchange layer plate 52 is provided with electrode gas channel holes 523 at the corresponding positions near the plate edge, which are respectively connected to the anode gas channel 512 and the cathode gas channel 511 on the anode electrode 515 and the cathode electrode 513;

[0036] In this embodiment, the tail gas heat recovery loop for recovering the heat energy of the tail gas includes a heat exchange structure connected to the tail gas outlet of the anode electrode 515 of SOFC5 and the fuel supply device 3, so as to collect the tail gas of the anode electrode 515 and transport it to the fuel supply device 3, perform heat exchange to recover the heat energy, so that the temperature of the residual fuel is further reduced, and then it is transported to the burner 8. The tail gas heat recovery loop also includes a heat exchange structure connected to the tail gas outlet of the cathode electrode 513 of SOFC5 and the oxygen supply device 4, so as to collect the tail gas of the cathode electrode 513 and transport it to the oxygen supply device 4, perform heat exchange to recover the heat energy, so that the temperature of the residual oxygen-containing gas is further reduced, and then it flows out to the burner 8, is mixed with the residual fuel and burned to release heat;

[0037] The optimal operating temperature of SOFC5 is 650-800°C. Therefore, in this embodiment, in order to maintain SOFC5 within the optimal operating temperature range and prevent it from overheating, a cooling circulation loop that can recover excess heat energy to achieve the purpose of heat dissipation is set. The cooling circulation loop is formed by the heat exchange layer plate 52 in SOFC5, the heat dissipation circulation pump 10 and the first heat exchanger 6 connected in series in sequence. Since SOFC5 is a high-temperature battery, the temperature inside it and the exhaust gas temperature are as high as 600°C or above. Conventional heat exchange medium (such as water) is used in the cooling circulation loop to cool the SOFC5 at this temperature. In order to prevent its gasification from causing excessive loop pressure, a very high circulation flow rate is often required, which consumes a large amount of additional power from the power system. Therefore, the present invention uses molten salt with large thermal quality and heat capacity as a coolant. The molten salt has strong thermal conductivity, low viscosity and good fluidity at high temperature. The heat dissipation circulation pump 10 can meet the cooling demand of SOFC5 at a lower flow rate, and the energy consumption is low. In order to adapt to the working temperature of SOFC5, the molten salt is preferably a binary or ternary inorganic molten salt with an operating temperature of 350°C-700°C, including but not limited to potassium nitrate, sodium nitrate, sodium nitrite and other inorganic molten salts and mixtures thereof. Through the stacked heat exchange layer plates 52, the heat energy on the surfaces of the two electrodes of each battery unit layer 51 inside SOFC5 is evenly output, the temperature gradient and thermal stress inside SOFC5 are reduced, and the service life of SOFC5 is increased. Moreover, the heat dissipation demand of SOFC5 can be quickly completed by running the heat dissipation circulation pump 10 at a lower rate for a shorter time, thereby reducing energy consumption.

[0038] In this embodiment, the power generation module can utilize the excess heat energy in the insulation layer of the submersible casing to generate electricity, thereby preventing the excess heat energy in the insulation layer from continuously accumulating and causing high temperature overheating of SOFC5. The power generation module includes a Stirling engine 9, a heat recovery circuit coupled to the hot end of the Stirling engine 9, and a generator 13 connected to the power output shaft of the Stirling engine 9, wherein the cold end of the Stirling engine 9 is coupled to the casing outside the insulation layer, and the water flow outside the submersible is used as the cold end. In other words, the temperature of the cold end is the natural water temperature. The higher the temperature of SOFC5, the higher the corresponding hot end temperature of the Stirling engine 9, the greater the temperature difference, and the higher the output power of the Stirling engine 9. The heat energy that cannot be used by SOFC5 is converted into electric energy through the power generation module, so that the heat energy can be converted into electric energy through the power generation module and further supplemented to the power system; wherein, the heat energy recovery loop is a closed circulation loop that sequentially connects the first heat exchanger 6 and the burner 8 in series and couples them to the hot end of the Stirling engine 9, and the heat exchange circulation pump 17 thereon drives the heat exchange medium to sequentially transport the heat energy of the first heat exchanger 6 and the burner 8 to the hot end of the Stirling engine 9. Similarly, the heat exchange medium is preferably the above-mentioned molten salt, because its operating temperature is relatively high, it can improve the temperature difference of the Stirling engine 9, and compared with heat exchange media such as water, its conversion efficiency is higher, and the heat exchange circulation pump 17 consumes less electric energy;

[0039] In this embodiment, the power control system includes a temperature control system (not shown), a first temperature sensor provided on the SOFC5, a drive control module 14 and a motor 15. Figure 1 In the structural diagram of the embodiment shown in the figure, SOFC5 and the generator 13 are connected in parallel at the first level, and then connected in series with the drive control module 14 and the motor 15. After being inverted and rectified into three-phase AC power of the same phase by the drive control module 14, the power is transmitted to the motor 15 to drive the motor 15 to work together; the first temperature sensor can be arranged on the exhaust gas outlet of the cathode electrode 513, and can also be arranged on the exhaust gas outlet of the anode electrode 515, and is used to collect the temperature of any electrode. The temperature control system receives the temperature signal of the first temperature sensor, and according to the preset opening temperature, that is, the set SOFC5 heat dissipation temperature threshold. , generally 800°C, send a control signal to the heat dissipation circulation pump 10 to start heat dissipation, and at the same time increase the speed of the heat exchange circulation pump 17. In addition, a third temperature sensor is set on the heat recovery loop to collect the molten salt temperature at the rear end of the burner 8. The third temperature sensor is connected to the temperature control system. When it is detected that the temperature reaches the preset heat cycle temperature, the heat exchange circulation pump 17 is turned on. Because the melting temperature of the molten salt is 200°C and the minimum working temperature is 350°C, the fluidity and viscosity of the molten salt at and above this temperature meet the requirements of the heat exchange medium, so the heat cycle temperature is generally set to 350°C;

[0040] As a further optimized design of this embodiment, a second temperature sensor and a heater 11 are sequentially arranged on the cooling circulation loop for collecting the molten salt temperature at the rear end of the first heat exchanger 6 and turning on the heater 11 as needed. This design can solve the problem of overheating caused by high-power power generation of SOFC5 in a short period of time and slow reaction of the cooling circulation loop. The temperature control system receives the first temperature sensor signal to start the heat dissipation circulation pump 10, but the molten salt temperature does not reach or the temperature is lower than the thermal cycle temperature after heat exchange through the first heat exchanger 6. Since the molten salt thermal cycle temperature is a priority control parameter, the temperature control system receives and prioritizes processing the temperature signal of the second temperature sensor, resulting in the failure of the heat dissipation circulation pump 10 to start effectively, thereby causing the overheated energy in SOFC5 to fail to be evacuated in a timely and effective manner. The heater 11 heats the molten salt at the outlet of the first heat exchanger 6 to increase its temperature, thereby quickly increasing the overall temperature of the cooling circulation loop to speed up its startup.

[0041] As a further optimized design of this embodiment, the power control system also includes a battery 12, which is used to supplement and alleviate power fluctuations when the submersible has sudden high-power power demands. For example, during sudden turns or accelerations, the battery 12 and the SOFC5 are connected in parallel at the secondary level, and the drive control module 14 sends a control signal to start and stop the power transmission line of the battery 12 according to the operating conditions and work requirements of the submersible.

[0042] According to the characteristics of the working conditions of the submersible, a long-term constant speed travel at a preset fixed rate is used as a common working condition. Therefore, a corresponding SOFC5 rated power is designed to avoid the submersible running at a condition lower than the rated power for a long time. With the continuous expansion of the functions of the submersible, such as the development of underwater action functions such as loading and underwater launching, Figure 1 The power system shown in the figure obviously cannot meet the use requirements, and replacing a new power system is obviously an unwise choice. Therefore, the present invention also provides the following Figure 2 Another exemplary embodiment of the submersible power system structure is shown in FIG. This embodiment is based on the previous embodiment and adds a power supplement circuit. The power supplement circuit uses Figure 1 The existing burner 8 in the embodiment is further expanded as a backup power source for the power system to simultaneously meet the power requirements of lower rated power operation and function expansion under common operating conditions of the submersible. The power supplement circuit includes a fuel branch connecting the fuel source 1 and the burner 8 and an oxygen branch connecting the oxygen source 2 and the burner 8. A control device 16 for controlling the gas flow is provided on both the fuel branch and the oxygen branch. The control device 16 receives a control signal sent by the drive control module 14 and is started according to the function implementation needs of the submersible.

[0043] As SOFC5 runs for a long time, the temperature in the thermal insulation layer of the submersible is maintained at a certain high temperature, and the heat recovery efficiency of the fuel supply device 3 and the oxygen supply device 4 for the tail gas gradually decreases. The direct combustion of the high-temperature fuel and the oxygen-containing gas will cause the burner 8 to release high energy quickly, and the heat recovery loop cannot take it away in time. Therefore, the present invention provides a Figure 3 The submersible power system structure shown in the best exemplary embodiment is based on Figure 2 On the basis of the implementation method of the shown embodiment, a second heat exchanger 7 is added. As the best implementation method disclosed in the present invention, it can use the heat recovery circuit to perform secondary recovery of exhaust gas heat energy. In the exhaust gas heat recovery circuit, the second heat exchanger 7 is located at the rear end of the burner 8. In the heat recovery circuit, the second heat exchanger 7 is located at the front end of the first heat exchanger 6. Therefore, the heat recovery circuit forms a three-stage heat exchange system according to the temperature gradient, which is the second heat exchanger 7, the first heat exchanger 6 and the burner 8 in sequence. The molten salt is gradually heated, which effectively improves the recovery efficiency of the heat recovery circuit, maximizes the use of the heat released by the SOFC5 system, and further improves the fuel utilization rate of SOFC5.

[0044] In the present invention, the terms "front end" and "rear end" indicate directions or positional relationships based on the flow direction of the fluid in the circuit.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A submersible power system based on solid oxide fuel cells, characterized in that: The device is configured on the submersible and located in the heat insulation layer of the submersible, including: A solid oxide fuel cell system, comprising a solid oxide fuel cell, a fuel supply device for controlling the delivery of a fuel source, and an oxygen supply device for controlling the delivery of an oxygen source, wherein the solid oxide fuel cell comprises an anode electrode and a cathode electrode, and a heat exchange structure is further provided therein; the solid oxide fuel cell is a layered stack structure, comprising a battery unit layer composed of the cathode electrode and the anode electrode of a plate-like structure, and an electrolyte layer located between the cathode electrode and the anode electrode, a plurality of the battery unit layers are stacked in sequence, and the heat exchange structure is a heat exchange layer plate sandwiched between the battery unit layers; An exhaust gas heat recovery circuit, on which a burner is provided, for collecting the exhaust gas from the anode electrode and transporting it to the fuel supply device, performing heat exchange to recover heat energy, and then transporting it to the burner; and for collecting the exhaust gas from the cathode electrode and transporting it to the oxygen supply device, performing heat exchange to recover heat energy, and then transporting it to the burner; A cooling circulation loop is formed by sequentially connecting the solid oxide fuel cell, the heat dissipation circulation pump and the first heat exchanger, and outputs the heat energy of the solid oxide fuel cell through the heat exchange structure; A power generation module, comprising a Stirling engine, a heat recovery loop coupled to the hot end of the Stirling engine, and a generator connected to the power output shaft of the Stirling engine, wherein the cold end of the Stirling engine is coupled to the casing outside the thermal insulation layer, and the heat recovery loop is driven by a heat exchange circulation pump to sequentially couple the first heat exchanger and the burner in series to the hot end of the Stirling engine; and, An electric power control system, comprising a temperature control system, a first temperature sensor provided on the solid oxide fuel cell, a drive control module and an electric motor, wherein the solid oxide fuel cell and the generator are connected in parallel at one level, and the electric power is transmitted to the electric motor after being inverted and converted by the drive control module, and the temperature control system receives a temperature signal from the first temperature sensor and sends a control signal to the heat dissipation circulation pump and the heat exchange circulation pump; Among them, the heat exchange medium in the cooling circulation loop and the heat recovery loop is molten salt, and the molten salt is a binary or ternary inorganic molten salt with an operating temperature of 350°C-700°C. A second temperature sensor and a heater are also arranged in sequence on the cooling circulation loop, located at the rear end of the first heat exchanger. The temperature control system receives the temperature signals of the first temperature sensor and the second temperature sensor, processes and sends control signals to the heater.

2. The submersible power system according to claim 1, characterized in that: The power control system further includes a battery, and the battery and the solid oxide fuel cell are connected in parallel at two levels. The drive control module sends a control signal to start and stop the power transmission of the battery.

3. The submersible power system according to claim 2, characterized in that: It also includes an electric power supplement circuit, including a fuel branch connecting the fuel source and the burner and an oxygen branch connecting the oxygen source and the burner, and the fuel branch and the oxygen branch are both provided with a control device for controlling the gas flow, and the control device receives a control signal for executing the drive control module.

4. The submersible power system according to claim 3, characterized in that: It also includes a second heat exchanger, which utilizes the heat energy recovery circuit to secondary recover the exhaust gas heat energy of the exhaust gas heat recovery circuit. In the heat energy recovery circuit, the second heat exchanger is located at the front end of the first heat exchanger, and in the exhaust gas heat recovery circuit, the second heat exchanger is located at the front end of the burner.

5. The submersible power system according to claim 1, characterized in that: The first temperature sensor is arranged on the tail gas outlet of the cathode electrode.

6. The submersible power system according to claim 1, characterized in that: The first temperature sensor is arranged on the tail gas outlet of the anode electrode.

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