Marine fuel cell zero carbon emission system machine and operation method thereof

Abstract

The invention discloses a marine LNG solid oxide fuel cell energy gradient utilization zero-carbon emission system and an operation method thereof. According to the technical scheme, the energy utilization rate can be effectively increased, gradient utilization of cold-heat-electricity composite energy can be achieved, and the technical advantages of pure electric power, low noise, no pollution, zero carbon emission and high energy efficiency of a ship system are reflected. The marine fuel cell zero carbon emission system comprises a solid oxide fuel cell-HCCI internal combustion engine module, an exhaust gas carbon capture module, an ORC cycle module, an air supply module, an external reforming module and an energy distribution module. The waste gas carbon capture module is used for capturing waste gas generated by the system and is used for being linked with the ORC circulation module. And the ORC cycle module is linked with the solid oxide fuel cell-HCCI internal combustion engine module. The air supply module is used for exchanging heat with the HCCI internal combustion engine through external air. The external reforming module is used for providing heat and water vapor to the reformer.

Description

Technical Field

[0001] This application relates to the technical field of marine fuel cells, and more specifically, to a marine fuel cell zero-carbon emission system machine and its operation method. Background Art

[0002] Carbon dioxide emissions from the shipping industry account for 2.5% of the global carbon emissions. With the increasing IMO carbon emission reduction requirements, the shipping industry needs new green ship technologies to achieve the zero-carbon goal in 2050. Currently, large LNG carriers and fueling ships all use low-speed dual-fuel engines. Limited by the maximum thermal efficiency of the Carnot cycle, the thermal efficiency is about 50%, and it is difficult to further effectively improve the thermal efficiency. Moreover, they face problems such as low thermal efficiency, high noise, and many auxiliary equipment under low load.

[0003] Solid oxide fuel cells are a type of high-efficiency electrochemical device with an operating temperature of 600 - 1000 °C. They can achieve a net electrical efficiency of about 60%, and the energy conversion efficiency of combined heat and power utilization can reach over 80%. They can use a variety of fuels, such as LNG, methanol, ammonia, etc. They have no mechanical moving parts, can achieve low noise and vibration, the products are environmentally friendly, can be modularly manufactured and installed, and have low requirements for the loading of noble metal catalysts. These characteristics show great technical potential in the green development of ships. Currently, the existing marine solid oxide fuel cell systems generally take small ships as the design prototype, without considering the system integration effect and comprehensive energy cycle utilization efficiency of large LNG ships, and have problems such as low energy utilization rate, poor system response ability, and unreasonable energy distribution. Summary of the Invention

[0004] This application provides a marine fuel cell zero-carbon emission system machine and its operation method. The technical solution provided by this application can effectively improve the energy utilization rate, realize the cascaded utilization of cold - heat - electricity composite energy, and reflect the technical advantages of pure electricity, low noise, pollution-free, zero-carbon emission, and high energy efficiency of the ship system.

[0005] To achieve the above object, this application provides the following technical solutions:

[0006] In the first aspect, this application provides a marine fuel cell zero-carbon emission system. The marine fuel cell zero-carbon emission system includes a solid oxide fuel cell - HCCI internal combustion engine module, an exhaust gas carbon capture module, an ORC cycle module, an air supply module, an external reforming module, and an energy distribution module;

[0007] The solid oxide fuel cell-HCCI internal combustion engine module includes a reformer, a solid oxide fuel cell, and an HCCI internal combustion engine. The solid oxide fuel cell-HCCI internal combustion engine is configured to reform LNG into hydrogen-rich reformed gas through the reformer, so as to be delivered to the solid oxide fuel cell to provide a raw material for an electrochemical reaction, so that the solid oxide fuel cell provides electrical energy to the energy distribution module, and the HCCI internal combustion engine provides electrical energy to the energy distribution module;

[0008] The exhaust gas carbon capture module is used to capture the exhaust gas generated by the capture system, and is used to be linked with the ORC cycle module and to provide heat to the reformer;

[0009] The ORC circulation module is linked to the solid oxide fuel cell-HCCI internal combustion engine module for heat exchange with LNG and for providing electrical energy to the energy distribution module;

[0010] The air supply module is used to utilize external air to exchange heat with the HCCI internal combustion engine and provide heat to the reformer, and is used to utilize cathode exhaust gas of the solid oxide fuel cell to provide heat to the reformer;

[0011] The external reforming module includes a water pump and a secondary heater, which is used to heat the water delivered by the water pump and provide heat and steam to the reformer;

[0012] The energy distribution module is used to distribute electrical energy to the hull.

[0013] According to some embodiments of the present application, the solid oxide fuel cell-HCCI internal combustion engine module further includes an LNG liquid cargo pump, a first three-way valve, a condenser, a four-stage heat exchanger, a three-stage heat exchanger, an anode preheating unit, a second three-way valve, a third three-way valve, a first control valve, a second control valve, a third control valve 3, an intake heat exchange unit, a steam-water separator, a first heat exchanger, and a second heat exchanger;

[0014] The outlet of the LNG cargo pump is connected to the inlet of the first three-way valve. The main path of the outlet of the three-way valve is connected to the ORC cycle module. The branch path of the outlet of the first three-way valve is connected to the inlet of the four-stage heat exchanger. The outlet of the three-stage heat exchanger is connected to the inlet of the reformer. The outlet of the reformer is connected to the inlet of the anode preheating unit. The outlet of the anode preheating unit is respectively connected to the first control valve and the main path inlet of the solid oxide fuel cell through the second three-way valve. The outlet of the anode preheating unit is connected to the third three-way valve, and successively passes through the intake air heat exchange unit, the steam-water separator, the second control valve, and the third control valve. The outlet of the third control valve is connected to the inlet of the HCCI internal combustion engine. The outlet of the HCCI internal combustion engine is connected to the inlet of the first-stage heat exchanger. The outlet of the first-stage heat exchanger is connected to the inlet of the second-stage heat exchanger. The outlet of the second-stage heat exchanger is connected to the inlet of the third-stage heat exchanger. The outlet of the third-stage heat exchanger is connected to the waste gas carbon capture module. The anode preheating unit exchanges heat between the outlet of the reformer and the tail gas at the anode outlet of the solid oxide fuel cell.

[0015] According to some embodiments of the present application, the waste gas carbon capture module includes a water separator, a PSA pressure swing adsorber, a compressor, and a liquid CO2 storage tank;

[0016] The inlet of the water separator is connected to the ORC cycle module. The outlet of the water separator is connected to the inlet of the PSA pressure swing adsorber. One side outlet of the PSA pressure swing adsorber discharges the treated low-carbon waste gas, and the other side is connected to the inlet of the compressor. The outlet of the compressor is connected to the inlet of the four-stage heat exchanger to condense CO2, and the outlet of the four-stage heat exchanger is connected to the inlet of the liquid CO2 storage tank to store liquid CO2.

[0017] According to some embodiments of the present application, the ORC cycle module includes a condenser, a transfer pump, an evaporator, a turbine, and a coaxial generator;

[0018] The inlet of the condenser is connected to the large end of the outlet of the turbine. The outlet of the condenser is connected to the inlet of the transfer pump. The outlet of the transfer pump is connected to the inlet of the evaporator. The outlet of the evaporator is connected to the small end of the inlet of the turbine. The turbine is connected to the coaxial generator and outputs electric energy to the energy distribution module.

[0019] According to some embodiments of the present application, the air supply module includes an air blower, an air compressor, a reversible motor, an exhaust gas turbine, and a fourth control valve;

[0020] The outlet of the air blower is connected to the inlet of the air compressor. The outlet of the air compressor is connected to the inlet of the first-stage heat exchanger. The outlet of the first-stage heat exchanger is connected to the fourth control valve 19. The fourth control valve 19 divides the preheated compressed air into two paths. The main path is connected to the cathode inlet of the solid oxide fuel cell. The cathode exhaust gas outlet of the solid oxide fuel cell is connected to the inlet of the exhaust gas turbine. The outlet of the exhaust gas turbine is connected to the inlet of the reforming heater. The branch of the fourth control valve is connected to the inlet of the third control valve. The outlet of the third control valve is connected to the inlet of the HCCI internal combustion engine, used to supply the mixed fuel gas to the HCCI internal combustion engine.

[0021] According to some embodiments of the present application, the external reforming module includes a reforming heater, a water pump, a second-stage heater, and a third-stage heater;

[0022] The inlet of the reforming heater is connected to the outlet of the exhaust gas turbine, providing the heat absorption required for the reforming reaction of the reformer. The inlet of the water pump is connected to the outlet of the condensate water pipeline from the steam-water separator. The outlet of the water pump is connected to the second-stage heater. The steam channel at the outlet of the second-stage heater is connected to the inlet of the reformer, providing the heat and steam required for the reforming reaction. The outlet of the third-stage heater is connected to the inlet of the reformer, supplying the fuel gas required for the reforming reaction.

[0023] According to some embodiments of the present application, the energy distribution module includes a unidirectional DC / DC module, a generator, a unidirectional AC / DC module, a bidirectional DC / DC module, a lithium battery module, a DC busbar, a DC / AC module, an electric motor, a propeller, other DC / AC modules, and other load modules;

[0024] The inlet of the unidirectional DC / DC module is connected to the solid oxide fuel cell, and the outlet is connected to the DC busbar. The inlet of the unidirectional AC / DC module is connected to the outlet of the generator coaxial with the HCCI internal combustion engine, and the outlet is connected to the DC busbar. The outlet of the lithium battery module is connected to the bidirectional DC / DC module, and the outlet of the bidirectional DC / DC module is connected to the DC busbar; The inlet of the DC / AC module is connected to the DC busbar, and the outlet is connected to the inlet of the electric motor. The outlet of the electric motor is connected to the propeller. The inlet of the other DC / AC modules is connected to the DC busbar, and the outlet is connected to other loads.

[0025] According to some embodiments of the present application, the intake heat exchange unit is a plate heat exchanger.

[0026] According to some embodiments of the present application, the reformer is a porous medium reactor. The catalyst of the reformer is nickel foam with a porosity of 0.6 - 0.8, and the conversion rate is not less than 0.6.

[0027] In a second aspect, some embodiments of the present application further provide an operation method for a marine fuel cell zero-carbon emission system, applying the marine fuel cell zero-carbon emission system of the first aspect. The method includes:

[0028] Utilizing the LNG flow, the solid oxide fuel cell-HCCI internal combustion engine module reforms the LNG into a hydrogen-rich reformed gas, which is then delivered to the solid oxide fuel cell to provide a raw material for an electrochemical reaction, thereby providing electrical energy to the energy distribution module;

[0029] Utilizing the exhaust gas flow, the exhaust gas generated by the system is captured through the exhaust gas carbon capture module and used to provide heat for the reforming reaction;

[0030] The working fluid is used to exchange heat with the LNG through the ORC circulation module and to provide electrical energy to the energy distribution module.

[0031] utilizing air flow to exchange heat with the HCCI internal combustion engine through an air supply module and supply heat to the reformer, and utilizing cathode exhaust gas from a solid oxide fuel cell to supply heat to the reformer;

[0032] Using water flow, heat and steam are supplied to the reformer through an external reforming module;

[0033] Electrical energy is distributed to the electrical components of the hull through the energy distribution module.

[0034] Compared with the related existing technologies, the technical solution provided by this application has the following beneficial effects:

[0035] 1. This invention utilizes LNG cold energy by establishing an ORC cycle between the HCCI engine exhaust and the LNG inlet. This drives the ORC cycle turbine to generate electricity, recovering primary cold energy from the LNG. Secondary cold energy from the LNG is then used to cool the CO2 after pressure swing adsorption to liquid CO2, achieving carbon dioxide capture. As the amount of CO2 in the exhaust gas recirculation increases, the heat load on the carbon capture module increases, and the cooling capacity gap is covered by the bypass flow of the three-way valve.

[0036] 2. The anode exhaust and cathode exhaust of the solid oxide fuel cell are discharged separately to increase the carbon dioxide enrichment in the anode exhaust gas, reduce the load of the carbon dioxide capture system, improve the efficiency of the carbon dioxide capture system, and achieve zero carbon emissions from the anode exhaust gas; the anode exhaust gas passes through a steam-water separator before entering the internal combustion engine to reduce the internal combustion gas inlet temperature and improve the efficiency of the internal combustion engine; the cathode air is low-oxygen air after the electrochemical reaction, and its thermal energy and mechanical energy are recovered through the exhaust turbine and reformer. The final exhaust gas discharged is zero-carbon clean exhaust gas, which can achieve zero carbon emissions and energy cascade utilization.

[0037] 3. By controlling the branch opening of the three-way valve, the flow rate of the hydrogen-rich reformed fuel gas entering the internal combustion engine can be adjusted, which can keep the solid oxide fuel cell working stably, improve the adaptability to load fluctuations, improve the combustion performance of the HCCI internal combustion engine, and increase the combustion thermal efficiency of the internal combustion engine.

[0038] 4. The energy distribution module involved in the present invention adopts a DC busbar, which can directly supply the DC power of the solid oxide fuel cell to the DC busbar, reducing the traditional AC distribution board, transformer and filter, reducing the system redundancy, and improving the system electrical efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 It is a schematic diagram of a marine fuel cell zero-carbon emission system and its operation method in some embodiments of the present application.

[0041] Reference numerals: 1 - liquid cargo pump; 2 - first three-way valve; 3 - condenser; 4 - delivery pump; 5 - evaporator; 6 - turbine; 7 - generator; 8 - water separator; 9 - PSA pressure swing adsorber; 10 - compressor; 11 - four-stage heat exchanger; 12 - liquid CO2 storage tank; 13 - three-stage heat exchanger; 14 - air blower; 15 - air compressor; 16 - coaxial reversible motor; 17 - exhaust gas turbine; 18 - first-stage heat exchanger; 19 - fourth control valve; 20 - reforming heat exchanger; 21 - reformer; 22 - water pump; 23 - second-stage heat exchanger; 24 - anode preheating unit; 25 - second three-way valve; 26 - solid oxide fuel cell; 27 - first control valve; 28 - third three-way valve; 29 - intake air preheating unit; 30 - steam-water separator; 31 - second control valve; 32 - third control valve; 33 - HCCI internal combustion engine; 34 - generator; 35 - single-phase AC / DC module; 36 - single-phase DC / DC module; 37 - lithium battery module; 38 - bidirectional DC / DC module; 39 - DC busbar; 40 - DC / AC module; 41 - electric motor; 42 - propeller; 43 - DC / AC module; 44 - other load modules. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. Components of the embodiments of this application usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts fall within the scope of protection of this application.

[0044] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0045] In the description of the embodiments of this application, it should be understood that the orientation or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships when the product of this application is in its usual placement, or the orientation or positional relationships commonly understood by those skilled in the art. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of this application.

[0046] In the description of the embodiments of this application, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0048] See Figure 1 , Figure 1 which is a schematic diagram of a marine fuel cell zero-carbon emission system and its operation method in some embodiments of this application.

[0049] The present application provides a marine fuel cell zero-carbon emission system, which includes a solid oxide fuel cell-HCCI internal combustion engine module, an exhaust gas carbon capture module, an ORC circulation module, an air supply module, an external reforming module and an energy distribution module.

[0050] The solid oxide fuel cell-HCCI internal combustion engine module includes a reformer 21, a solid oxide fuel cell 26, and an HCCI internal combustion engine 33. The solid oxide fuel cell-HCCI internal combustion engine module is configured to reform LNG into hydrogen-rich reformed gas via the reformer 21, which is then fed to the solid oxide fuel cell 26 to provide feedstock for the electrochemical reaction. This allows the solid oxide fuel cell 26 to supply electrical energy to the energy distribution module, and the HCCI internal combustion engine 33 to supply electrical energy to the energy distribution module. The exhaust gas carbon capture module is used to collect exhaust gas generated by the capture system, is linked to the ORC circulation module, and provides heat to the reformer 21. The ORC circulation module is linked to the solid oxide fuel cell-HCCI internal combustion engine module to exchange heat with LNG and provide electrical energy to the energy distribution module. The air supply module is used to utilize external air for heat exchange with the HCCI internal combustion engine 33, to provide heat to the reformer 21, and to utilize cathode exhaust gas from the solid oxide fuel cell 26 to provide heat to the reformer 21. The external reforming module includes a water pump 22 and a secondary heater 23. The secondary heater 23 is used to heat the water delivered by the water pump 22 and provide heat and steam to the reformer 21. The energy distribution module is used to distribute electrical energy to the hull.

[0051] In some embodiments of the present application, specifically, the solid oxide fuel cell-HCCI internal combustion engine module includes: an LNG liquid cargo pump 1, a first three-way valve 2, a condenser 3, a four-stage heat exchanger 11, a three-stage heat exchanger 13, a reformer 21, an anode preheating unit 24, a solid oxide fuel cell 26, a second three-way valve 25, a third three-way valve 28, a first control valve 27, a second control valve 31, a third control valve 32, an intake heat exchange unit 29, a steam-water separator 30, an HCCI internal combustion engine 33, a first-stage heat exchanger 18, and a second-stage heat exchanger 23; the outlet of the LNG liquid cargo pump 1 is connected to the inlet of the first three-way valve 2, the main path of the outlet of the three-way valve is sequentially connected to the condenser 3 of the ORC cycle, the four-stage heat exchanger 11, and the three-stage heat exchanger 13, the branch of the outlet of the first three-way valve 2 is connected to the inlet of the four-stage heat exchanger 11, the outlet of the three-stage heat exchanger 13 is connected to the inlet of the reformer 21, the outlet of the reformer 21 is connected to the inlet of the anode preheating unit 24, the outlet of the anode preheating unit 24 is respectively connected to the first control valve 27 of the branch and the main path inlet of the solid oxide fuel cell 26 through the second three-way valve 25, the outlet of the anode preheating unit 24 is connected to the third three-way valve 28, and sequentially passes through the intake heat exchange unit 29, the steam-water separator 30, and the second control valve 31 and the third control valve 32, the outlet of the third control valve 32 is connected to the inlet of the HCCI internal combustion engine 33, the outlet of the HCCI internal combustion engine 33 is connected to the inlet of the first-stage heat exchanger 18, the outlet of the first-stage heat exchanger 18 is connected to the inlet of the second-stage heat exchanger 23, the outlet of the second-stage heat exchanger 23 is connected to the inlet of the three-stage heat exchanger 13, and the outlet of the three-stage heat exchanger 13 is connected to the waste gas carbon capture module. The anode preheating unit 24 performs heat exchange before the outlet of the anode reformer 21 and the tail gas at the outlet of the anode 26.

[0052] The waste gas carbon capture module includes: a water separator 8, a PSA pressure swing adsorber 9, a compressor 10, a four-stage heat exchanger 11, and a liquid CO2 storage cabinet 12. The inlet of the water separator 8 is connected to the outlet of the ORC evaporator 5, the outlet of the water separator 8 is connected to the inlet of the PSA pressure swing adsorber 9, one side outlet of the PSA pressure swing adsorber 9 discharges the treated low-carbon waste gas, and the other side is connected to the inlet of the compressor 10. The outlet of the compressor 10 is connected to the inlet of the four-stage heat exchanger 11 to condense CO2, and the outlet of the four-stage heat exchanger 11 is connected to the inlet of the liquid CO2 storage cabinet 12 to store liquid CO2.

[0053] The ORC cycle module includes: a condenser 3, a delivery pump 4, an evaporator 5, a turbine 6, and a coaxial generator 7. The inlet of the condenser 3 is connected to the large end of the outlet of the turbine 6, the outlet of the condenser 3 is connected to the inlet of the delivery pump 4, the outlet of the delivery pump 4 is connected to the inlet of the evaporator 5, the outlet of the evaporator 5 is connected to the small end of the inlet of the turbine 6, and the turbine 6 is connected to the coaxial generator 7 to output electric energy to the energy distribution module.

[0054] The air supply module includes: an air blower 14, an air compressor 15, a reversible motor 16, an exhaust gas turbine 17, a primary heat exchanger 18, a fourth control valve 19, and a third control valve 32. The outlet of the air blower 14 is connected to the inlet of the air compressor 15. The outlet of the air compressor 15 is connected to the inlet of the primary heat exchanger 18. The outlet of the primary heat exchanger 18 is connected to the fourth control valve 19. The fourth control valve 19 divides the preheated compressed air into two paths. The main path is connected to the cathode inlet of the solid oxide fuel cell 26. The cathode exhaust gas outlet of the solid oxide fuel cell 26 is connected to the inlet of the exhaust gas turbine 17. The outlet of the exhaust gas turbine 17 is connected to the inlet of the reforming heater 20. The fourth control valve 19 is connected to the inlet of the third control valve 32 in the branch. The outlet of the third control valve 32 is connected to the inlet of the HCCI internal combustion engine 33 to supply the mixed fuel gas to the HCCI internal combustion engine 33.

[0055] The external reforming module includes: a reforming heater 20, a reformer 21, a water pump 22, a secondary heater 23, and a tertiary heater 13. The inlet of the reforming heater 20 is connected to the outlet of the exhaust gas turbine 17 to provide the heat absorption required for the reforming reaction of the reformer 21. The inlet of the water pump 22 is connected to the outlet of the condensate water pipeline from the steam-water separator 30. The outlet of the water pump 22 is connected to the secondary heater 23. The steam channel at the outlet of the secondary heater 23 is connected to the inlet of the reformer 21 to provide the heat and steam required for the reforming reaction. The outlet of the tertiary heater 13 is connected to the inlet of the reformer 21 to supply the fuel gas required for the reforming reaction.

[0056] The energy distribution module includes: a unidirectional DC / DC module 36, a generator 34, a unidirectional AC / DC module 35, a bidirectional DC / DC module 38, a lithium battery module 37, a DC busbar 39, a DC / AC module 40, an electric motor 41, a propeller 42, another DC / AC module 43, and another load module 44. The inlet of the unidirectional DC / DC module 36 is connected to the solid oxide fuel cell 26, and the outlet is connected to the DC busbar 39. The inlet of the unidirectional AC / DC module 35 is connected to the outlet of the generator 34 coaxial with the HCCI internal combustion engine 33, and the outlet is connected to the DC busbar 39. The outlet of the lithium battery module 37 is connected to the bidirectional DC / DC module 38, and the outlet of the bidirectional DC / DC module 38 is connected to the DC busbar 39. The unidirectional DC / DC module 36, the unidirectional AC / DC module 35, and the bidirectional DC / DC module 38 on the energy supply side are connected to each other. The inlet of the DC / AC module 10 is connected to the DC busbar 39, and the outlet is connected to the inlet of the electric motor 41. The outlet of the electric motor 41 is connected to the propeller 42. The inlet of another DC / AC module 43 is connected to the DC busbar 39, and the outlet is connected to another load 44.

[0057] As an embodiment, the HCCI internal combustion engine adopts lean combustion technology, performs homogeneous charge compression ignition by uniformly mixing fuel gas and air, and can improve the indicated thermal efficiency of the HCCI internal combustion engine and the energy conversion efficiency of the solid oxide fuel cell-HCCI internal combustion engine module by controlling the bypass flow rate of the rich hydrogen reformed gas in the branches of the second three-way valve 25 and the first control valve 27.

[0058] As an embodiment, the branch flow rate at the outlet of the LNG three-way valve is determined by the required cooling capacity of the four-stage heat exchanger, and can be adjusted by closed-loop feedback control of the flow rate following the change of the heat load of the carbon capture system.

[0059] As an embodiment, the intake heat exchange unit 29 is a plate heat exchanger, which establishes heat exchange between the inlet and outlet of the steam-water separator, can reduce the intake temperature of the steam-water separator while increasing the fuel temperature at the inlet of the HCCI internal combustion engine, and plays the role of recovering the heat of the anode exhaust gas and improving the efficiency of the HCCI internal combustion engine.

[0060] As an embodiment, the working fluid used in the ORC cycle is an organic working fluid, such as ethylene glycol, etc.;

[0061] As an embodiment, the coaxial reversible motor 16 is a permanent magnet synchronous motor. As an embodiment, the reversible motor 16 is coaxially installed with the air compressor 15 and the exhaust gas turbine 17, operates as a motor to drive the compressor 15 at startup and low loads, and as an embodiment, the coaxial reversible motor 16 outputs electrical energy to the single-phase AC / DC module 35 as a generator at high loads.

[0062] As an embodiment, the reformer is a porous medium reactor, the catalyst is nickel foam with a porosity of 0.6-0.8, and the conversion rate is not less than 0.6.

[0063] As an embodiment, the fuel utilization rate of the anode reforming of the solid oxide fuel cell 22 is controlled at 0.7.

[0064] As an embodiment, the energy distribution module is a DC busbar, which can make the whole ship a pure electric system. Connecting the bidirectional DC / DC 38 to the DC busbar 39 can achieve rapid load response, rapid charging of the lithium battery module 37, withstand load fluctuations, and improve the service life and working performance of the system. As an embodiment, compared with the marine AC busbar, the DC busbar 39 reduces the current transmission loss, reduces the cable requirement specifications, increases the optimal operating point range of the ship-engine-propeller, and reduces the complexity of the power distribution system.

[0065] It should be noted that there are a total of five material flows in this system: LNG flow, water flow, air flow, working fluid flow, and exhaust gas flow; one energy flow: electric energy flow. Taking the LNG carrier as an example, the working principle of this system is as follows:

[0066] (1) LNG flow: The liquid cargo pump 1 transports liquid LNG from the LNG storage tank into the pipeline. After being heated successively by the ORC cycle condenser 3, the four-stage heat exchanger 11, and the three-stage heat exchanger 13, it is fed into the reformer 21 for reforming reaction. The hydrogen-rich reformed gas after reforming is heated by the anode preheating unit 24, and the main path of the heated anode reformed gas is fed into the anode of the solid oxide fuel cell 26 for electrochemical reaction; the branch path is mixed evenly with the cooled anode exhaust gas and then fed into the HCCI internal combustion engine 33 for combustion reaction.

[0067] (2) Water flow: Low-temperature fresh water is transported by the water pump 22. After heat exchange with the secondary heat exchanger 23, it becomes high-temperature steam and enters the reformer 21 for reforming reaction; the water vapor in the anode exhaust gas of the solid oxide fuel cell 26 is cooled by the cooling water after passing through the steam-water separator 30 to become condensed water, and the condensed water becomes the low-temperature fresh water make-up water and enters the water cycle.

[0068] (3) Air flow: Air enters the inlet of the air compressor 15 through the air blower 14. Under the combined action of the coaxial motor 16 and the exhaust gas turbine 17, it is compressed. The compressed air exchanges heat with the exhaust gas at the outlet of the HCCI internal combustion engine 33 through the primary heat exchanger 18. After that, the heated compressed air is mixed with the anode exhaust gas mixture and fed into the HCCI internal combustion engine 33 for combustion.

[0069] (4) Working medium flow: The organic working medium exchanges heat with the exhaust gas of the HCCI internal combustion engine 33 through the evaporator 5. The produced high-temperature and high-pressure steam is fed into the turbine 6 to expand and do work, driving the generator 7 to convert mechanical energy into electrical energy. The steam discharged from the turbine 6 exchanges heat with LNG in the condenser 3. The condensed liquid working medium is fed into the evaporator under the action of the feed pump 4.

[0070] (5) Exhaust gas flow: The exhaust gas flow is divided into anode exhaust gas and cathode exhaust gas at the outlet of the solid oxide fuel cell 26. Among them, the anode exhaust gas flow: The exhaust gas of the HCCI internal combustion engine first exchanges heat with the compressed air through the primary heat exchanger 18, then exchanges heat with the cooling water through the secondary heat exchanger 23, then exchanges heat with gaseous LNG through the three-stage heat exchanger 13, then exchanges heat with the ORC cycle evaporator 5, and then successively passes through the water separator 8 to separate water, the PSA 9 for pressure swing adsorption to separate N2, is compressed by the compressor 10, and finally exchanges heat with LNG through the four-stage heat exchanger 11, and the liquid carbon dioxide is stored in the liquid carbon dioxide storage cabinet 12.

[0071] Cathode exhaust gas flow: The cathode outlet exhaust gas of the solid oxide fuel cell 26 is high-temperature exhaust gas with a low oxygen content. It is fed into the exhaust gas turbine 17 to drive the impeller to rotate and drive the coaxial motor 16 and the compressor 15. The exhaust gas at the outlet of the exhaust gas turbine 17 enters the reformer 21 to provide the heat for the steam reforming of methane, and finally the low-temperature clean exhaust gas is discharged into the environment.

[0072] (6) Power flow: The power flow is divided into the supply side and the load side, and energy is distributed through the DC busbar 39. Supply side: The coaxial generator 7 connected to the ORC cycle turbine 6 outputs AC power to the unidirectional AC / DC module 35, which is converted into DC power through the AC / DC inverter and supplied to the DC busbar 39; the solid oxide fuel cell 26 generates DC power through electrochemical reaction and supplies it to the DC busbar through the unidirectional DC / DC module 36; the lithium battery module 37 is connected to the DC busbar 39 through the bidirectional DC / DC module 38, which can achieve fast DC charging and discharging; the HCCI internal combustion engine 33 drives the generator 34 to generate electricity, and the generated AC power is converted into DC power after passing through the unidirectional AC / DC module 35 and connected to the DC busbar 39; the coaxial generator 16 outputs electric energy under high load and is connected to the DC busbar through the unidirectional AC / DC module 35 for power supply.

[0073] Load end: The DC / AC module 40 is connected to the DC busbar 39. The inverted AC power is converted into mechanical energy through the electric motor 41 to drive the coaxial propeller 42 to rotate. A pod can also be used to connect to the DC / AC module 40; other ship loads are connected to the DC busbar 39 through the DC / AC module 43; the coaxial reversible motor 16 consumes electrical energy at low load and is connected to the DC busbar 39 through the DC / AC module 43.

[0074] It should be noted that the present application also provides a method for operating a marine fuel cell zero-carbon emission system, which utilizes the marine fuel cell zero-carbon emission system described above, and the method includes:

[0075] Utilizing the LNG flow, the solid oxide fuel cell-HCCI internal combustion engine module reforms the LNG into a hydrogen-rich reformed gas, which is then delivered to the solid oxide fuel cell to provide a raw material for an electrochemical reaction, thereby providing electrical energy to the energy distribution module;

[0076] Utilizing the exhaust gas flow, the exhaust gas generated by the system is captured through the exhaust gas carbon capture module and used to provide heat for the reforming reaction;

[0077] The working fluid is used to exchange heat with the LNG through the ORC circulation module and to provide electrical energy to the energy distribution module.

[0078] utilizing air flow to exchange heat with the HCCI internal combustion engine through an air supply module and supply heat to the reformer, and utilizing cathode exhaust gas from a solid oxide fuel cell to supply heat to the reformer;

[0079] Using water flow, heat and steam are supplied to the reformer through an external reforming module;

[0080] Electrical energy is distributed to the electrical components of the ship through the energy distribution module.

[0081] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A marine fuel cell zero carbon emission system, characterized in that: The marine fuel cell zero-carbon emission system includes a solid oxide fuel cell-HCCI internal combustion engine module, an exhaust gas carbon capture module, an ORC circulation module, an air supply module, an external reforming module and an energy distribution module; The solid oxide fuel cell-HCCI internal combustion engine module includes a reformer, a solid oxide fuel cell, and an HCCI internal combustion engine. The solid oxide fuel cell-HCCI internal combustion engine module is configured to reform LNG into hydrogen-rich reformed gas through the reformer, so as to transmit the hydrogen-rich reformed gas to the solid oxide fuel cell to provide a raw material for an electrochemical reaction, so that the solid oxide fuel cell provides electrical energy to the energy distribution module, and the HCCI internal combustion engine provides electrical energy to the energy distribution module. The exhaust gas carbon capture module is used to capture the exhaust gas generated by the capture system, and is used to be linked with the ORC cycle module, and is used to provide heat to the reformer; The ORC circulation module is linked to the solid oxide fuel cell-HCCI internal combustion engine module for exchanging heat with the LNG and for providing electrical energy to the energy distribution module; The air supply module is used to utilize external air to exchange heat with the HCCI internal combustion engine and provide heat to the reformer, and is used to utilize cathode exhaust gas from the solid oxide fuel cell to provide heat to the reformer; The external reforming module includes a water pump and a secondary heater, wherein the secondary heater is used to heat the water delivered by the water pump and provide heat and steam to the reformer; The energy distribution module is used to distribute electrical energy to the hull.

2. The marine fuel cell zero carbon emission system according to claim 1, characterized in that: The solid oxide fuel cell-HCCI internal combustion engine module further includes an LNG liquid cargo pump, a first three-way valve, a condenser, a four-stage heat exchanger, a three-stage heat exchanger, an anode preheating unit, a second three-way valve, a third three-way valve, a first control valve, a second control valve, a third control valve, an intake heat exchange unit, a steam-water separator, a first heat exchanger, and a second heat exchanger; The outlet of the LNG liquid cargo pump is connected to the inlet of the first three-way valve. The main outlet of the three-way valve is connected to the ORC cycle module. The branch outlet of the first three-way valve is connected to the inlet of the four-stage heat exchanger. The outlet of the three-stage heat exchanger is connected to the inlet of the reformer. The outlet of the reformer is connected to the inlet of the anode preheating unit. The outlet of the anode preheating unit is respectively connected to the first control valve and the main inlet of the solid oxide fuel cell through the second three-way valve. The outlet of the anode preheating unit is connected to the third three-way valve, and successively passes through the intake air heat exchange unit, the steam-water separator, the second control valve, and the third control valve. The outlet of the third control valve is connected to the inlet of the HCCI internal combustion engine. The outlet of the HCCI internal combustion engine is connected to the inlet of the first-stage heat exchanger. The outlet of the first-stage heat exchanger is connected to the inlet of the second-stage heat exchanger. The outlet of the second-stage heat exchanger is connected to the inlet of the third-stage heat exchanger. The outlet of the third-stage heat exchanger is connected to the waste gas carbon capture module. The anode preheating unit exchanges heat between the outlet of the reformer and the anode outlet exhaust gas of the solid oxide fuel cell.

3. The marine fuel cell zero-carbon emission system according to claim 2, wherein the waste gas carbon capture module includes a water separator, a PSA pressure swing adsorber, a compressor 10, and a liquid CO2 storage tank; the inlet of the water separator is connected to the ORC cycle module. The outlet of the water separator is connected to the inlet of the PSA pressure swing adsorber. One side outlet of the PSA pressure swing adsorber discharges the treated low-carbon waste gas, and the other side is connected to the inlet of the compressor. The outlet of the compressor is connected to the inlet of the four-stage heat exchanger to condense CO2. The outlet of the four-stage heat exchanger is connected to the inlet of the liquid CO2 storage tank to store liquid CO2.

4. The marine fuel cell zero-carbon emission system according to claim 2, wherein the ORC cycle module includes a condenser, a transfer pump, an evaporator, a turbine, and a coaxial generator; the inlet of the condenser is connected to the large end of the outlet of the turbine. The outlet of the condenser is connected to the inlet of the transfer pump. The outlet of the transfer pump is connected to the inlet of the evaporator. The outlet of the evaporator is connected to the small end of the inlet of the turbine. The turbine is connected to the coaxial generator and outputs electric energy to the energy distribution module.

5. The marine fuel cell zero-carbon emission system according to claim 2, wherein the air supply module includes an air blower, an air compressor, a reversible motor, an exhaust gas turbine, and a fourth control valve; The outlet of the air blower is connected to the inlet of the air compressor 15. The outlet of the air compressor is connected to the inlet of the primary heat exchanger. The outlet of the primary heat exchanger is connected to the fourth control valve. The fourth control valve divides the preheated compressed air into two paths. The main path is connected to the cathode inlet of the solid oxide fuel cell. The cathode exhaust gas outlet of the solid oxide fuel cell is connected to the inlet of the exhaust gas turbine. The outlet of the exhaust gas turbine is connected to the inlet of the reforming heater. The branch of the fourth control valve is connected to the inlet of the third control valve. The outlet of the third control valve is connected to the inlet of the HCCI internal combustion engine to supply the mixed fuel gas to the HCCI internal combustion engine.

6. The marine fuel cell zero-carbon emission system according to claim 5, wherein the external reforming module includes a reforming heater, a water pump, a secondary heater, and a tertiary heater; the inlet of the reforming heater is connected to the outlet of the exhaust gas turbine to provide the heat absorption required for the reforming reaction of the reformer. The inlet of the water pump is connected to the outlet of the condensate water pipeline from the steam-water separator. The outlet of the water pump is connected to the secondary heater. The steam channel at the outlet of the secondary heater is connected to the inlet of the reformer to provide the heat and steam required for the reforming reaction. The outlet of the tertiary heater is connected to the inlet of the reformer to supply the fuel gas required for the reforming reaction.

7. The marine fuel cell zero-carbon emission system according to claim 5, wherein the energy distribution module includes a unidirectional DC / DC module, a generator, a unidirectional AC / DC module, a bidirectional DC / DC module, a lithium battery module, a DC bus bar, a DC / AC module, an electric motor, a propeller, another DC / AC module, and another load module; the inlet of the unidirectional DC / DC module is connected to the solid oxide fuel cell, and the outlet is connected to the DC bus bar. The inlet of the unidirectional AC / DC module is connected to the outlet of the generator coaxial with the HCCI internal combustion engine, and the outlet is connected to the DC bus bar. The outlet of the lithium battery module is connected to the bidirectional DC / DC module, and the outlet of the bidirectional DC / DC module is connected to the DC bus bar. The inlet of the DC / AC module is connected to the DC bus bar, and the outlet is connected to the inlet of the electric motor. The outlet of the electric motor is connected to the propeller. The inlet of the other DC / AC module is connected to the DC bus bar, and the outlet is connected to the other load.

8. The marine fuel cell zero-carbon emission system according to claim 2, wherein the intake heat exchange unit is a plate heat exchanger.

9. The marine fuel cell zero-carbon emission system according to claim 1, wherein the reformer is a porous medium reactor. The catalyst of the reformer is nickel foam with a porosity of 0.6 - 0.8, and the conversion rate is not less than 0.

6.

10. A method for operating a zero-carbon emission system of a marine fuel cell, characterized in that, Applying the marine fuel cell zero-carbon emission system according to claim 1, the method includes: Utilizing the LNG flow, reforming the LNG into hydrogen-rich reformed gas through the solid oxide fuel cell-HCCI internal combustion engine module, and delivering the gas to the solid oxide fuel cell to provide a raw material for an electrochemical reaction, thereby providing electrical energy to the energy distribution module; Utilizing the exhaust gas flow to capture the exhaust gas generated by the system through the exhaust gas carbon capture module and using it to provide heat for the reforming reaction; Utilizing the working fluid flow, through the ORC circulation module and the solid oxide fuel cell-HCCI internal combustion engine module, for heat exchange with the LNG and for providing electrical energy to the energy distribution module; utilizing air flow to exchange heat with the HCCI internal combustion engine through the air supply module and provide heat to the reformer, and utilizing cathode exhaust gas from the solid oxide fuel cell to provide heat to the reformer; providing heat and steam to the reformer via the external reforming module using a water flow; The energy distribution module distributes electrical energy to the electrical components of the ship.

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