Ship compound power system and control method and device thereof

Abstract

The application discloses a ship compound power system and a control method and device thereof, and relates to the technical field of ship power engineering. When the working power of a fuel engine is high, part of exhaust gas of the fuel engine provides heat for a reforming reaction subsystem, and part of the exhaust gas is used as raw material for a reforming reaction, and the reforming gas obtained by the reforming reaction subsystem is all recycled by the fuel engine. When the working power of the fuel engine is low, the fuel cell is controlled to be turned on to ensure power, and all the exhaust gas of the fuel engine is used to provide heat required by the system, and the hydrogen-rich reforming gas under the low working condition of the fuel engine is recycled to the fuel engine and the fuel cell for reuse. In the working process of the ship compound power system, a fuel cold energy processing subsystem exchanges heat between the fuel in a fuel storage tank and the reforming gas of the reforming reaction subsystem, improves the heat efficiency of the system, and liquefies and recovers carbon dioxide in the reforming gas.

Description

Technical Field

[0001] This invention relates to the field of marine power engineering technology, and in particular to a marine composite power system and its control method and device. Background Technology

[0002] With the development of international trade, air pollution from ships at sea has become increasingly serious. Traditional marine fuel oil releases large amounts of harmful gases such as sulfides during combustion. To reduce the generation of these gases, ships using various CHx fuels (mainly represented by methane, ethane, methanol, and other natural gas) and NH3 as fuels have emerged. Simultaneously, hydrogen blending is employed to compensate for the problems of CHx and NH3 fuels, such as their susceptibility to misfire and slow combustion rate at high air-fuel ratios.

[0003] However, the issues of H2 source and storage remain unresolved, limiting the direct use of H2 in engines. Therefore, real-time online exhaust gas-fuel reforming and recirculation (REGR) technology is being applied to engines. This involves installing a reformer at the engine exhaust pipe, using waste heat from the engine as catalytic converter (part of the exhaust gas, fuel, and H2O) to produce hydrogen-rich gas (reformed gas), which is then recirculated back into the engine for combustion. This technology addresses waste heat recovery and the H2 source issue, while also improving engine performance and emissions.

[0004] However, REGR technology's exhaust gas treatment is only applicable to high-speed engine operation; it doesn't consider exhaust gas treatment under low-load conditions, resulting in poor applicability. Furthermore, in REGR technology, when hydrocarbons are used as fuel, the reforming reaction produces CO2 gas. Directly recirculating untreated reformed gas into the engine increases carbon emissions, significantly impacting the environment. Additionally, current reforming systems only consider the reuse of waste heat from engine exhaust, leading to low energy efficiency for the entire powertrain system. Summary of the Invention

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a marine hybrid propulsion system and its control method and device, which provides exhaust gas treatment with strong applicability to different engine operating conditions, reduces carbon emissions, and improves system thermal efficiency.

[0006] On one hand, embodiments of the present invention provide a marine hybrid propulsion system, including a fuel engine, an exhaust gas recirculation valve, a reforming reaction subsystem, an engine exhaust gas heat utilization subsystem, a fuel storage tank, a fuel cold energy treatment subsystem, a fuel cell, a first solenoid valve, and a control processor;

[0007] The exhaust gas outlet of the fuel cell engine is connected to the inlet of the exhaust gas recirculation valve. The first outlet of the exhaust gas recirculation valve is connected to the reforming reaction subsystem, and the second outlet of the exhaust gas recirculation valve is connected to the engine exhaust gas heat utilization subsystem. The reformed gas outlet of the reforming reaction subsystem is connected to the inlet of the first solenoid valve. The first outlet of the first solenoid valve is connected to the fuel cell, and the second outlet of the first solenoid valve is connected to the fuel cell engine. The control processor is electrically connected to the exhaust gas recirculation valve, the first solenoid valve, and the fuel cell engine. The fuel cooling energy treatment subsystem is used to use fuel in the fuel tank to perform heat exchange on the reformed gas of the reforming reaction subsystem and then recover it to the fuel cell engine or the reforming reaction subsystem to provide fuel.

[0008] The control processor is used for:

[0009] Obtain the operating power of the fuel engine;

[0010] When the operating power is greater than the first threshold, the first outlet and the second outlet of the exhaust gas recirculation valve are both opened, the first outlet of the first solenoid valve is closed, and the second outlet of the first solenoid valve is opened.

[0011] When the operating power is less than or equal to the first threshold, the first outlet of the exhaust gas recirculation valve is closed, the second outlet of the exhaust gas recirculation valve is opened, both the first and second outlets of the first solenoid valve are opened, and the fuel cell is turned on.

[0012] According to some embodiments of the present invention, the reforming reaction subsystem includes a reforming gas generating unit and a reforming gas processing unit, the reforming gas processing unit including a reforming gas water removal subunit, a first reforming gas channel, a second reforming gas channel, and a second solenoid valve; the fuel cooling energy processing subsystem is used to cool the reforming gas in the first reforming gas channel to liquefy carbon dioxide.

[0013] The reformed gas outlet of the reformed gas generating unit is connected to the reformed gas inlet of the reformed gas dewatering subunit. The reformed gas outlet of the reformed gas dewatering subunit is connected to the inlet of the second solenoid valve. The first outlet of the second solenoid valve is connected to the first reformed gas channel. The second outlet of the second solenoid valve is connected to the second reformed gas channel. The reformed gas outlets of the first and second reformed gas channels are both connected to the inlet of the first solenoid valve.

[0014] According to some embodiments of the present invention, the fuel storage tank is connected to the inlet of a third solenoid valve, the first outlet of the third solenoid valve is connected to the fuel cooling energy processing subsystem, and the second outlet of the third solenoid valve is connected to the reforming reaction subsystem.

[0015] According to some embodiments of the present invention, the control processor is further configured to:

[0016] When the fuel is natural gas, the first outlet of the third solenoid valve is opened, the first outlet of the second solenoid valve is opened, and the second outlet of the second solenoid valve is closed.

[0017] When the fuel is not natural gas, the first outlet of the third solenoid valve is closed, the second outlet of the third solenoid valve is opened, the first outlet of the second solenoid valve is closed, and the second outlet of the second solenoid valve is opened.

[0018] According to some embodiments of the present invention, the fuel cooling energy treatment subsystem includes a first fuel delivery channel, a first heat exchanger and a second heat exchanger, the first fuel delivery channel passing through the first heat exchanger and the second heat exchanger in sequence, and the first fuel delivery channel passing through the engine exhaust heat utilization subsystem.

[0019] The first reforming gas channel passes through a first heat exchanger and a second heat exchanger in sequence; a first compressor is installed on the first reforming gas channel section between the first outlet of the second solenoid valve and the first heat exchanger; a second compressor, a pressure reducing valve, and a pressure sensor are installed in sequence on the first reforming gas channel section between the first heat exchanger and the second heat exchanger; a gas-liquid separator is installed between the second heat exchanger and the inlet of the first solenoid valve; the reforming gas outlet of the gas-liquid separator is connected to the inlet of the first solenoid valve, and the liquefied carbon dioxide outlet of the gas-liquid separator is connected to a carbon dioxide storage tank.

[0020] According to some embodiments of the present invention, the engine exhaust heat utilization subsystem includes a first engine exhaust passage, a third heat exchanger, a fourth heat exchanger, and a carbon dioxide adsorbent.

[0021] After passing through the reformer housing of the reforming gas generating unit, the first engine exhaust gas passage passes sequentially through the third heat exchanger, the fourth heat exchanger, and the carbon dioxide adsorbent.

[0022] The steam outlet channel of the reforming gas dehydration subunit is connected to the reforming gas generating unit after passing through the third heat exchanger.

[0023] The first fuel delivery channel of the fuel cooling energy processing subsystem is connected to the fuel engine or the reforming gas generation unit after passing through the fourth heat exchanger.

[0024] According to some embodiments of the present invention, the ship hybrid propulsion system further includes a battery exhaust heat utilization subsystem, which includes a burner, a fifth heat exchanger, a sixth heat exchanger and a turbocharger connected in sequence.

[0025] The exhaust gas outlet of the fuel cell is connected to the inlet of the burner, and the outlet of the turbocharger is connected to the power pump or compressor in the marine hybrid power system.

[0026] According to some embodiments of the present invention, the marine hybrid propulsion system further includes an air passage that is connected to the fuel engine and the fuel cell respectively, and the air passage is connected to the fuel cell via the fifth heat exchanger;

[0027] The channel where the first outlet of the first solenoid valve is located is connected to the fuel cell via the sixth heat exchanger.

[0028] On the other hand, embodiments of the present invention also provide a control method for a ship's composite propulsion system, applied to the ship's composite propulsion system as described in the first aspect embodiment above, the control method comprising the following steps:

[0029] To obtain the operating power of the fuel engine;

[0030] When the operating power is greater than the first threshold, the first and second outlets of the exhaust gas recirculation valve are both opened, the first outlet of the first solenoid valve is closed, and the second outlet of the first solenoid valve is opened.

[0031] When the operating power is less than or equal to the first threshold, the first outlet of the exhaust gas recirculation valve is closed, the second outlet of the exhaust gas recirculation valve is opened, both the first and second outlets of the first solenoid valve are opened, and the fuel cell is turned on.

[0032] On the other hand, embodiments of the present invention also provide a control device for a ship's hybrid propulsion system, comprising:

[0033] At least one processor;

[0034] At least one memory for storing at least one program;

[0035] When the at least one program is executed by the at least one processor, the at least one processor implements the control method for the ship's composite propulsion system as described above.

[0036] The technical solution described above has at least one of the following advantages or beneficial effects: The control processor implements different exhaust gas treatment methods for different operating conditions of the fuel engine. When the fuel engine's operating power is high, both the first and second outlets of the exhaust gas recirculation valve are opened, allowing some of the fuel engine's exhaust gas to provide heat to the reforming reaction subsystem, and some of the exhaust gas to be used as raw material for the reforming reaction. Simultaneously, the first outlet of the first solenoid valve is closed and the second outlet is opened, ensuring that all the reformed gas obtained by the reforming reaction subsystem is recycled by the fuel engine. When the fuel engine's operating power is low, the fuel cell is controlled to operate to ensure power. The first and second outlets of the exhaust gas recirculation valve are closed and opened, allowing all the fuel engine's exhaust gas to be used to provide the system's required heat. Simultaneously, both the first and second outlets of the first solenoid valve are opened, allowing the hydrogen-rich reformed gas under low operating conditions of the fuel engine to be recovered and reused by the fuel engine and fuel cell. Furthermore, during the operation of the ship's hybrid propulsion system, the fuel cold energy treatment subsystem uses fuel in the fuel storage tank to exchange heat with the reformed gas of the reforming reaction subsystem, improving the system's thermal efficiency while liquefying and recovering carbon dioxide from the reformed gas. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a ship's composite propulsion system provided in an embodiment of the present invention;

[0038] Figure 2 This is a flowchart of the control method for a ship's composite propulsion system provided in an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the control device for a ship's composite propulsion system provided in an embodiment of the present invention. Detailed Implementation

[0040] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar originals or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0041] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0042] In the description of this invention, the use of terms such as "first," "second," etc., is merely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0043] This invention provides a marine composite propulsion system, referring to... Figure 1 The marine hybrid propulsion system includes a fuel engine 104, an exhaust gas recirculation valve 105, a reforming reaction subsystem 200, an engine exhaust gas heat utilization subsystem 100, a fuel storage tank 101, a fuel cooling energy treatment subsystem 300, a fuel cell 129, a first solenoid valve 125, and a control processor (not shown in the figure). The exhaust gas outlet of the fuel engine is connected to the inlet of the exhaust gas recirculation valve. The first outlet of the exhaust gas recirculation valve is connected to the reforming reaction subsystem, and the second outlet of the exhaust gas recirculation valve is connected to the engine exhaust gas heat utilization subsystem. The reformed gas outlet of the reforming reaction subsystem is connected to the inlet of the first solenoid valve. The first outlet of the first solenoid valve is connected to the fuel cell, and the second outlet of the first solenoid valve is connected to the fuel engine. The control processor is electrically connected to the exhaust gas recirculation valve, the first solenoid valve, and the fuel engine. The fuel cooling energy treatment subsystem uses fuel from the fuel storage tank to perform heat exchange with the reformed gas of the reforming reaction subsystem and then recovers it to the fuel engine or the reforming reaction subsystem to provide fuel.

[0044] The control processor is used for:

[0045] To obtain the operating power of the fuel engine;

[0046] When the operating power exceeds a first threshold, both the first and second outlets of the exhaust gas recirculation valve are opened, the first outlet of the first solenoid valve is closed, and the second outlet of the first solenoid valve is opened. Specifically, when the fuel engine's operating power is high, both the first and second outlets of the exhaust gas recirculation valve are opened, so that part of the exhaust gas from the fuel engine provides heat to the reforming reaction subsystem, and part of the exhaust gas is used as feedstock for the reforming reaction. At the same time, the first outlet of the first solenoid valve is closed and the second outlet is opened, so that all the reformed gas obtained by the reforming reaction subsystem is recycled by the fuel engine.

[0047] When the operating power is less than or equal to a first threshold, the first outlet of the exhaust gas recirculation valve is closed, the second outlet of the exhaust gas recirculation valve is opened, both the first and second outlets of the first solenoid valve are opened, and the fuel cell is turned on. Specifically, when the fuel cell's operating power is low, the fuel cell is turned on to ensure power. The first and second outlets of the exhaust gas recirculation valve are closed and opened so that all the exhaust gas from the fuel cell is used to provide the heat required by the system. This improves the exhaust gas utilization rate and allows for the switching of different reforming types without the need for an additional independent hydrogen production system for the fuel cell, reducing system costs. Simultaneously, both the first and second outlets of the first solenoid valve are opened so that the hydrogen-rich reformed gas from the fuel cell under low operating conditions can be recovered for reuse in the fuel cell and fuel cell.

[0048] According to some embodiments of the present invention, please continue to refer to Figure 1 The fuel cooling energy treatment subsystem includes a first fuel delivery channel, a first heat exchanger 117 and a second heat exchanger 120. The first fuel delivery channel passes through the first heat exchanger and the second heat exchanger in sequence, and is connected to the engine exhaust heat utilization subsystem.

[0049] According to some embodiments of the present invention, please continue to refer to Figure 1 The reforming reaction subsystem includes a reformed gas generation unit and a reformed gas processing unit. The reformed gas processing unit includes a reformed gas dehydration subunit, a first reformed gas channel, a second reformed gas channel, and a second solenoid valve 115. A fuel cooling subsystem is used to cool the reformed gas in the first reformed gas channel to liquefy carbon dioxide. The reformed gas outlet of the reformed gas generation unit is connected to the reformed gas inlet of the reformed gas dehydration subunit. The reformed gas outlet of the reformed gas dehydration subunit is connected to the inlet of the second solenoid valve. The first outlet of the second solenoid valve is connected to the first reformed gas channel, and the second outlet of the second solenoid valve is connected to the second reformed gas channel. The reformed gas outlets of both the first and second reformed gas channels are connected to the inlet of the first solenoid valve.

[0050] Specifically, the reforming gas generation unit includes a premixer 107 and a reformer 108. The premixer can be used to mix fuel, steam, and exhaust gas, while the reformer is used to reform the input feedstock to obtain reformed gas. The reforming gas dehydration subunit includes a condenser 110, a power pump 109, and a water storage tank 111. The power pump is used to deliver cooling water from the water storage tank to the condenser. The condenser uses the cooling water to condense the moisture in the reformed gas and delivers the condensed water to the water storage tank. The cooling water, controlled by the flow valve 131, absorbs heat and vaporizes, then exchanges heat with the exhaust gas in the engine exhaust heat utilization subsystem, continuously increasing its temperature and becoming one of the feedstocks for the reforming reaction.

[0051] The control processor controls the opening or closing of the first and second outlets of the second solenoid valve, allowing the reformed gas from the reformed gas dehydration subunit to enter either the first or second reformed gas channel. The first reformed gas channel passes sequentially through the first heat exchanger 117 and the second heat exchanger 120. A first compressor 116 is installed on the first reformed gas channel section between the first outlet of the second solenoid valve 115 and the first heat exchanger. A second compressor 118, a pressure reducing valve 119, and a pressure sensor 121 are sequentially installed on the first reformed gas channel section between the first and second heat exchangers. A gas-liquid separator 123 is installed between the second heat exchanger and the inlet of the first solenoid valve 125. The reformed gas outlet of the gas-liquid separator is connected to the inlet of the first solenoid valve, and the liquefied carbon dioxide outlet of the gas-liquid separator is connected to the carbon dioxide storage tank 122. The second reformed gas channel is used to cool and decarbonize the carbon dioxide-containing reformed gas. The second reformed gas channel is directly connected from the second outlet of the second solenoid valve 115 to the first solenoid valve 125.

[0052] According to some embodiments of the present invention, the fuel storage tank is connected to the inlet of the third solenoid valve 132, the first outlet of the third solenoid valve is connected to the fuel cooling energy treatment subsystem, and the second outlet of the third solenoid valve is connected to the reforming reaction subsystem.

[0053] According to some embodiments of the present invention, the control processor is further configured to:

[0054] When the fuel is natural gas, the first outlet of the third solenoid valve opens, the first outlet of the second solenoid valve opens, and the second outlet of the second solenoid valve closes. Specifically, if the fuel storage tank uses liquefied natural gas (LNG), the gasification process requires the absorption of a large amount of heat, and the reformed natural gas contains a significant amount of carbon dioxide. Therefore, when the control processor receives a signal from the ship's hybrid propulsion system that natural gas is being used, the first outlet of the third solenoid valve opens, allowing the LNG to enter the first fuel delivery channel and flow through the first and second heat exchangers to cool the reformed gas. Simultaneously, the first outlet of the second solenoid valve opens and the second outlet closes, controlling the reformed gas after passing through the condenser to enter the first reformed gas channel for cooling and carbon dioxide removal.

[0055] When the fuel is not natural gas, the first outlet of the third solenoid valve is closed, and the second outlet of the third solenoid valve is opened. Conversely, the first outlet of the second solenoid valve is closed, and the second outlet of the second solenoid valve is opened. Specifically, when the control processor receives a signal that the ship's hybrid propulsion system is using non-natural gas, the first outlet of the third solenoid valve is closed, allowing the reforming reaction to proceed directly. Simultaneously, the first outlet of the second solenoid valve is closed, and the second outlet is opened, controlling the reformed gas after passing through the condenser to enter the second reformed gas channel and be directly recycled to the fuel engine.

[0056] According to some embodiments of the present invention, please continue to refer to Figure 1 The engine exhaust heat utilization subsystem includes a first engine exhaust gas passage, a third heat exchanger 112, a fourth heat exchanger 113, and a carbon dioxide adsorbent 114. The first engine exhaust gas passage passes through the reformer casing of the reforming gas generation unit, and then sequentially passes through the third heat exchanger, the fourth heat exchanger, and the carbon dioxide adsorbent. The water vapor outlet passage of the reforming gas dehydration subunit is further heated by the third heat exchanger and then connected to the reforming gas generation unit. The first fuel delivery passage of the fuel cold energy treatment subsystem is vaporized by the fourth heat exchanger and then connected to the fuel engine or the reforming gas generation unit.

[0057] According to some embodiments of the present invention, please continue to refer to Figure 1 The marine hybrid propulsion system also includes a battery exhaust heat utilization subsystem, which comprises a burner 128, a fifth heat exchanger 126, a sixth heat exchanger 127, and a turbocharger 124 connected in sequence. The battery exhaust outlet of the fuel cell is connected to the burner inlet, and the turbocharger outlet is connected to the power pump or compressor in the marine hybrid propulsion system. The marine hybrid propulsion system also includes an air passage, which is connected to both the fuel engine and the fuel cell. The air passage is connected to the fuel cell via the fifth heat exchanger. The passage containing the first outlet of the first solenoid valve is connected to the fuel cell via the sixth heat exchanger.

[0058] The following is combined Figure 1 The embodiments of the present invention will be further described and illustrated.

[0059] When the plug-fuel engine 104 is under medium-to-high load conditions, both exhaust gas outlets of the exhaust gas recirculation valve 105 (EGR valve) are open. The engine exhaust gas is divided into two parts by the EGR valve. One part is mixed evenly with preheated fuel and water vapor in the premixer 107 and then enters the multi-fuel reformer 108 to produce a hydrogen-rich mixture (reformed gas). The other part flows through the reformer's outer casing to provide heat for the reforming reaction. The reformer is designed to be attached to the pipeline using screws or other easily removable connections instead of welding. This allows for changes in the type and amount of catalyst in the reformed gas when different fuel types are used, increasing the reformer's versatility. Cooling water in the water tank 111 is pumped by the power pump 109 to the condenser 110, where the water in the reformed gas is condensed and collected in the water tank for water circulation. The cooling water, controlled by the flow valve 131, absorbs heat and vaporizes, then exchanges heat with the exhaust gas in the third heat exchanger 112, continuously increasing its temperature and becoming one of the raw materials for the reforming reaction.

[0060] When the engine fuel (excluding LNG) does not contain significant cold energy, the dehydrated cryogenic reformed gas is directly mixed with air in the air passage via the second solenoid valve 115 and the first solenoid valve 125 before entering the fuel engine. Simultaneously, the fuel in the fuel tank 101 is directly transported to the fourth heat exchanger 113 for preheating without being diverted. Then, it is divided into two parts by the gas diversion valve 130: one part enters the reformer as a reaction feedstock, and the other part enters the engine as a combustion feedstock. The fuel volumetric flow rate can be monitored using a flow controller 103.

[0061] When the engine fuel is LNG, which possesses a large amount of cold energy, the reformed gas, after moisture removal, enters the first compressor 116 through the second solenoid valve 115 for initial compression, and the gas temperature rises accordingly. At this time, all the LNG transported from the fuel storage tank is sent to the first heat exchanger 117 to absorb the heat from the reformed gas for preliminary preheating of the LNG. A shut-off valve 102 is installed at the outlet of the fuel storage tank to prevent backflow of vaporized LNG and avoid excessive pressure at the tank opening. After preliminary cooling and pressurization, the reformed gas enters the second compressor 118 for further pressurization to approximately 4 MPa, then flows through the pressure reducing valve 119 into the second heat exchanger 120, where the cold energy of the LNG is used again to cool the gas to approximately -75°C, liquefying the CO2 in the reformed gas. Meanwhile, the LNG in the first fuel transport channel of the second heat exchanger is partially vaporized, and then further heated and vaporized by engine waste heat through the fourth heat exchanger 113, thus achieving multi-stage utilization of LNG cold energy recovery and engine waste heat. The reformed gas after liquefying CO2 enters the gas-liquid separator 123, the CO2 flows out from its lower end and enters the carbon dioxide storage tank 122, and the mixed gas (reformed gas) flows out from the upper port of the gas-liquid separator and enters the fuel engine.

[0062] When the engine is under low load, the solid oxide fuel cell 129 is activated as an auxiliary power source for the fuel engine, controlling the EGR valve to close. All engine exhaust gas flows through the reformer casing to provide heat for the steam reforming reaction within the tube bundle. The reformed gas output from the reformer contains a large amount of H2. When the fuel is LNG, after condensation to remove moisture and CO2 capture and separation, the H2 concentration of the reformed gas increases. The reformed gas is divided into two parts at the first solenoid valve 125: one part enters the engine, and the other part enters the solid oxide fuel cell. Simultaneously, because the fuel cell exhaust gas contains unreacted fuel, burning the fuel cell exhaust gas in the burner 128 produces high-temperature exhaust gas. This high-temperature exhaust gas passes sequentially through the fifth heat exchanger 126 and the sixth heat exchanger 127 before entering the turbocharger 124 to convert heat into work, which is used to power various pumps and compressors in the system. Finally, the exhaust gas is cooled, and the condensed H2O is collected in a water storage tank, while the high-temperature steam can be used in the reforming reaction. The fifth heat exchanger 126 and the sixth heat exchanger 127 are used to heat air and hydrogen-rich reformed gas, respectively.

[0063] In this embodiment of the invention, the exhaust gas from the fuel engine and burner, after multiple waste heat recovery processes, is fed into a carbon dioxide adsorbent 114, thereby achieving zero carbon emissions from the ship. Furthermore, temperature and pressure sensors can be installed in the pipeline, for example... Figure 1 The temperature sensor 133 and pressure sensor 121 shown are used to detect and acquire the temperature and pressure of the inlet and outlet materials of the fuel engine, reformer, and fuel cell, as well as before and after cooling or heating, so as to make real-time adjustments to the system based on the sensor data.

[0064] Reference Figure 2 The present invention also provides a control method for a ship hybrid propulsion system, applied to the aforementioned ship hybrid propulsion system. The control method includes, but is not limited to, the following steps:

[0065] Step S110: Obtain the operating power of the fuel engine;

[0066] Step S120: When the working power is greater than the first threshold, the first outlet and the second outlet of the exhaust gas recirculation valve are both opened, the first outlet of the first solenoid valve is closed, and the second outlet of the first solenoid valve is opened.

[0067] In step S130, when the operating power is less than or equal to the first threshold, the first outlet of the exhaust gas recirculation valve is closed, the second outlet of the exhaust gas recirculation valve is opened, the first and second outlets of the first solenoid valve are both opened, and the fuel cell is turned on.

[0068] Specifically, when the engine is running, the operating power of the fuel engine is detected. When the operating power of the fuel engine is less than or equal to a first threshold, the first outlet of the EGR valve is closed, and the fuel supply solenoid valve is switched to both the engine and the fuel cell simultaneously. Furthermore, the fuel injection pulse width of the engine can be adjusted to a first preset state on the control processor according to the combined power output mode of the fuel engine and fuel cell at this time. When the operating power of the fuel engine is greater than the first threshold, the first outlet of the EGR valve is opened, and the fuel supply solenoid valve is switched to the fuel engine only. Furthermore, the fuel injection pulse width can be adjusted to a second preset state according to the power output mode of the pure fuel engine. The control processor switches between different operating modes through valves based on the engine power signal to achieve the output power requirements under different operating conditions of the ship.

[0069] Furthermore, the control processor acquires the gas temperature output from the reformer, and when the gas temperature exceeds a second threshold, it controls to increase the flow rate of cooling water into the condenser. In addition, the marine hybrid propulsion system can switch and adjust the opening of various valves based on output signals for fuel type, power output, temperature, and pressure.

[0070] According to some specific embodiments of the present invention, the embodiments of the present invention have the following beneficial effects:

[0071] The marine hybrid power system of this invention provides a solution for the cascade utilization and carbon removal of waste heat from fuel engines, fuel cells, and reforming gas, which improves the system's thermal efficiency to a certain extent while achieving zero carbon emissions.

[0072] In this embodiment of the invention, H2O in the reformed gas is condensed and collected as one of the system feeds, reducing the supply of external water and power pump electricity, and saving energy.

[0073] This invention, through a control processor that controls the EGR valve to switch between different reforming types in conjunction with different power output modes, can, to a certain extent, assist in situations where engine power output is insufficient, optimizing the ship's operation under all conditions. Furthermore, it eliminates the need for a separate hydrogen production system for the fuel cell, reducing system costs. Simultaneously, by utilizing waste heat to preheat the intake gases for the fuel cell and fuel engine, it improves the system's rapid start-up response capability. In addition, the ship's hybrid propulsion system can reduce problems such as high pollutant emissions and vibration issues caused by the engine under low load.

[0074] Reference Figure 3 , Figure 3 This is a schematic diagram of a control device for a marine hybrid propulsion system according to an embodiment of the present invention. The control device for the marine hybrid propulsion system of this embodiment includes one or more control processors and a memory. Figure 3 The example consists of a control processor and a memory.

[0075] The control processor and memory can be connected via a bus or other means. Figure 3 Taking the example of a connection between China and Israel via a bus.

[0076] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the control processor, and these remote memories can be connected to the control device of the ship's hybrid propulsion system via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0077] Those skilled in the art will understand that Figure 3The device structure shown does not constitute a limitation on the control device of a ship's composite propulsion system, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0078] The non-transient software program and instructions required to implement the control method of the ship composite power system applied to the control device of the ship composite power system in the above embodiments are stored in the memory. When the controlled processor executes, the control method of the ship composite power system applied to the control device of the ship composite power system in the above embodiments is executed.

[0079] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A marine composite propulsion system, characterized in that, It includes a fuel engine, an exhaust gas recirculation valve, a reforming reaction subsystem, an engine exhaust gas heat utilization subsystem, a fuel storage tank, a fuel cold energy treatment subsystem, a fuel cell, a first solenoid valve, and a control processor; The exhaust gas outlet of the fuel cell engine is connected to the inlet of the exhaust gas recirculation valve. The first outlet of the exhaust gas recirculation valve is connected to the reforming reaction subsystem, and the second outlet of the exhaust gas recirculation valve is connected to the engine exhaust gas heat utilization subsystem. The reformed gas outlet of the reforming reaction subsystem is connected to the inlet of the first solenoid valve. The first outlet of the first solenoid valve is connected to the fuel cell, and the second outlet of the first solenoid valve is connected to the fuel cell engine. The control processor is electrically connected to the exhaust gas recirculation valve, the first solenoid valve, and the fuel cell engine. The fuel cooling energy treatment subsystem is used to use fuel in the fuel tank to perform heat exchange on the reformed gas of the reforming reaction subsystem and then recover it to the fuel cell engine or the reforming reaction subsystem to provide fuel. The control processor is used for: Obtain the operating power of the fuel engine; When the operating power is greater than the first threshold, the first outlet and the second outlet of the exhaust gas recirculation valve are both opened, the first outlet of the first solenoid valve is closed, and the second outlet of the first solenoid valve is opened. When the operating power is less than or equal to the first threshold, the first outlet of the exhaust gas recirculation valve is closed, the second outlet of the exhaust gas recirculation valve is opened, both the first and second outlets of the first solenoid valve are opened, and the fuel cell is turned on. The reforming reaction subsystem includes a reforming gas generation unit and a reforming gas processing unit. The reforming gas processing unit includes a reforming gas water removal subunit, a first reforming gas channel, a second reforming gas channel, and a second solenoid valve. The fuel cooling energy processing subsystem is used to cool the reforming gas in the first reforming gas channel to liquefy carbon dioxide. The reformed gas outlet of the reformed gas generating unit is connected to the reformed gas inlet of the reformed gas dewatering subunit. The reformed gas outlet of the reformed gas dewatering subunit is connected to the inlet of the second solenoid valve. The first outlet of the second solenoid valve is connected to the first reformed gas channel. The second outlet of the second solenoid valve is connected to the second reformed gas channel. The reformed gas outlets of the first and second reformed gas channels are both connected to the inlet of the first solenoid valve.

2. The marine composite propulsion system according to claim 1, characterized in that, The fuel storage tank is connected to the inlet of the third solenoid valve, the first outlet of the third solenoid valve is connected to the fuel cold energy treatment subsystem, and the second outlet of the third solenoid valve is connected to the reforming reaction subsystem.

3. The marine composite propulsion system according to claim 2, characterized in that, The control processor is also used for: When the fuel is natural gas, the first outlet of the third solenoid valve is opened, the first outlet of the second solenoid valve is opened, and the second outlet of the second solenoid valve is closed. When the fuel is not natural gas, the first outlet of the third solenoid valve is closed, the second outlet of the third solenoid valve is opened, the first outlet of the second solenoid valve is closed, and the second outlet of the second solenoid valve is opened.

4. The marine composite propulsion system according to claim 1, characterized in that, The fuel cooling energy treatment subsystem includes a first fuel delivery channel, a first heat exchanger, and a second heat exchanger. The first fuel delivery channel passes through the first heat exchanger and the second heat exchanger in sequence, and the first fuel delivery channel is connected to the engine exhaust heat utilization subsystem. The first reforming gas channel passes through a first heat exchanger and a second heat exchanger in sequence; a first compressor is installed on the first reforming gas channel section between the first outlet of the second solenoid valve and the first heat exchanger; a second compressor, a pressure reducing valve, and a pressure sensor are installed in sequence on the first reforming gas channel section between the first heat exchanger and the second heat exchanger; a gas-liquid separator is installed between the second heat exchanger and the inlet of the first solenoid valve; the reforming gas outlet of the gas-liquid separator is connected to the inlet of the first solenoid valve, and the liquefied carbon dioxide outlet of the gas-liquid separator is connected to a carbon dioxide storage tank.

5. The marine composite propulsion system according to claim 4, characterized in that, The engine exhaust heat utilization subsystem includes a first engine exhaust passage, a third heat exchanger, a fourth heat exchanger, and a carbon dioxide adsorption device. After passing through the reformer housing of the reforming gas generating unit, the first engine exhaust gas passage passes sequentially through the third heat exchanger, the fourth heat exchanger, and the carbon dioxide adsorbent. The steam outlet channel of the reforming gas dehydration subunit is connected to the reforming gas generating unit after passing through the third heat exchanger. The first fuel delivery channel of the fuel cooling energy processing subsystem is connected to the fuel engine or the reforming gas generation unit after passing through the fourth heat exchanger.

6. The marine composite propulsion system according to claim 1, characterized in that, The ship's hybrid propulsion system also includes a battery exhaust heat utilization subsystem, which includes a burner, a fifth heat exchanger, a sixth heat exchanger, and a turbocharger connected in sequence. The exhaust gas outlet of the fuel cell is connected to the inlet of the burner, and the outlet of the turbocharger is connected to the power pump or compressor in the marine hybrid power system.

7. The marine composite propulsion system according to claim 6, characterized in that, The ship's hybrid propulsion system also includes an air passage that is connected to the fuel engine and the fuel cell, respectively, and the air passage is connected to the fuel cell via the fifth heat exchanger; The channel where the first outlet of the first solenoid valve is located is connected to the fuel cell via the sixth heat exchanger.

8. A control method for a ship's composite propulsion system, characterized in that, Applied to any one of the ship hybrid propulsion systems as described in claims 1 to 7, the control method includes the following steps: To obtain the operating power of the fuel engine; When the operating power is greater than the first threshold, the first and second outlets of the exhaust gas recirculation valve are both opened, the first outlet of the first solenoid valve is closed, and the second outlet of the first solenoid valve is opened. When the operating power is less than or equal to the first threshold, the first outlet of the exhaust gas recirculation valve is closed, the second outlet of the exhaust gas recirculation valve is opened, both the first and second outlets of the first solenoid valve are opened, and the fuel cell is turned on.

9. A control device for a ship's composite propulsion system, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the control method for a ship's composite propulsion system as described in claim 8.

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