Gas supply system for LNG dual-fuel main engine, and LNG dual-fuel powered ship

Abstract

A gas supply system for an LNG dual-fuel main engine, and an LNG dual-fuel powered ship. The gas supply system comprises an LNG supply unit (10), a dual-fuel main engine (20), an electrolytic hydrogen production unit (30), an exhaust gas recirculation unit (40), and a cold and heat circulation unit (50). The LNG supply unit (10) comprises an LNG storage tank (11), a submersible pump (12), an LNG heat exchanger (13) and a buffer tank (14). The electrolytic hydrogen production unit (30) comprises a pure water unit (31), a pure water heat exchanger (32), an electrolytic cell (33), a hydrogen storage tank (34), and an oxygen storage tank (35). The exhaust gas recirculation unit (40) comprises a flue gas heat exchanger (41). The cold and heat circulation unit (50) comprises an expansion water tank (51) and a circulation pump (52).

Description

Gas supply system of LNG dual-fuel main engine and LNG dual-fuel power ship TECHNICAL FIELD

[0001] The present application relates to the field of ship technology, in particular to a gas supply system of an LNG dual-fuel main engine and an LNG dual-fuel power ship with the gas supply system of the LNG dual-fuel main engine. BACKGROUND

[0002] With the gradual improvement of marine environmental protection awareness, the emission requirements for ships are becoming more and more stringent. The International Maritime Organization has promulgated a series of anti-pollution conventions related to ship emissions, and has formulated detailed emission standards for nitrogen oxides and sulfur oxides and other pollutants. According to the provisions of Annex VI of MARPOL 73 / 78 promulgated by the International Maritime Organization: After 2020, for marine low-speed engines, the nitrogen oxide emission limit is 14.4g / kW•h, and the sulfur oxide emission limit is 0.5%m / m in the non-control area; in the ECA area (emission control area), the nitrogen oxide emission limit is 3.4g / kW•h, and the sulfur oxide emission limit is 0.1%m / m. For carbon oxide emissions, the IMO International Maritime Organization has also formulated the latest carbon emission EEDI standard, which puts forward higher requirements for ship design, ship supporting equipment, new energy technology application, etc. The conventional fuel-powered ship emits exhaust gas containing a large amount of carbon dioxide, sulfur oxides, nitrogen oxides, etc., which will cause serious greenhouse gas effect, photochemical smog, acid rain and other pollution, endangering the global climate and human health.

[0003] LNG ships, as the most popular clean energy for ships at present, have been widely promoted and applied, but LNG ships still emit carbon dioxide and nitrogen oxides, which can only be treated by an exhaust gas aftertreatment system. The current exhaust gas aftertreatment system has the disadvantages of high energy consumption, solvent corrosion and volatilization, and large size and clumsiness, and it is difficult to promote in the field of ships.

[0004] In addition, in the LNG ship, the LNG fuel needs to be heated and vaporized during use, which will release a large amount of high-quality cold energy. The current LNG heating and vaporization treatment method is generally cylinder jacket water or boiler hot water heating, which will cause waste of LNG cold energy. TECHNICAL SOLUTION

[0005] The purpose of the present application is to provide a gas supply system of an LNG dual-fuel main engine and an LNG dual-fuel power ship, which improves the thermal efficiency value of the dual-fuel main engine, effectively reduces the energy consumption of the carbon dioxide capture process, and realizes the recovery and utilization of LNG cold energy.

[0006] The application provides a gas supply system of an LNG dual-fuel main engine, which comprises an LNG supply unit, a dual-fuel main engine, an electrolytic hydrogen production unit, an exhaust gas recirculation unit and a cold and heat energy circulation unit; the LNG supply unit comprises an LNG storage tank, a submerged pump, an LNG heat exchanger and a buffer tank; the electrolytic hydrogen production unit comprises a pure water unit, a pure water heat exchanger, an electrolytic cell, a hydrogen storage tank and an oxygen storage tank; the exhaust gas recirculation unit comprises a flue gas heat exchanger; and the cold and heat energy circulation unit comprises an expansion water tank and a circulating pump.

[0007] The submerged pump is arranged in the LNG storage tank, the outlet of the submerged pump is communicated with the LNG inlet of the LNG heat exchanger, the LNG outlet of the LNG heat exchanger is communicated with the inlet of the buffer tank, and the outlet of the buffer tank is communicated with the first gas inlet of the dual-fuel main engine.

[0008] The water outlet of the pure water unit is communicated with the pure water inlet of the pure water heat exchanger, the pure water outlet of the pure water heat exchanger is communicated with the water inlet of the electrolytic cell, the hydrogen outlet of the electrolytic cell is communicated with the inlet of the hydrogen storage tank, the first outlet of the hydrogen storage tank is communicated with the pipeline between the outlet of the buffer tank and the first gas inlet of the dual-fuel main engine, the oxygen outlet of the electrolytic cell is communicated with the inlet of the oxygen storage tank, and the outlet of the oxygen storage tank is communicated with the second gas inlet of the dual-fuel main engine.

[0009] The flue gas outlet of the dual-fuel main engine is communicated with the flue gas inlet of the flue gas heat exchanger, the flue gas outlet of the flue gas heat exchanger is communicated with the pipeline between the outlet of the oxygen storage tank and the second gas inlet of the dual-fuel main engine, and

[0010] The outlet of the expansion water tank is communicated with the inlet of the circulating pump, the outlet of the circulating pump is communicated with the circulating medium inlet of the pure water heat exchanger through a first branch, the circulating medium outlet of the pure water heat exchanger is communicated with the circulating medium inlet of the LNG heat exchanger, the outlet of the circulating pump is also communicated with the circulating medium inlet of the flue gas heat exchanger through a second branch, the circulating medium outlet of the flue gas heat exchanger is communicated with the circulating medium inlet of the LNG heat exchanger, and the circulating medium outlet of the LNG heat exchanger is communicated with the pipeline between the outlet of the expansion water tank and the inlet of the circulating pump.

[0011] Further, the LNG supply unit further comprises a gas supply main valve, which is arranged on the pipeline between the outlet of the buffer tank and the first gas inlet of the dual-fuel main engine, and the first outlet of the hydrogen storage tank is communicated with the pipeline between the outlet of the gas supply main valve and the first gas inlet of the dual-fuel main engine.

[0012] Further, the electrolytic hydrogen production unit further comprises a hydrogen regulating valve and an oxygen regulating valve, the hydrogen regulating valve is arranged on a pipeline connected with the first outlet of the hydrogen storage tank, and the oxygen regulating valve is arranged on a pipeline connected with the outlet of the oxygen storage tank; the flue gas outlet of the flue gas heat exchanger is communicated to a pipeline between the outlet of the oxygen regulating valve and the second gas inlet of the dual-fuel main engine.

[0013] Further, the exhaust gas recirculation unit further comprises a flue gas regulating valve arranged on a pipeline between the flue gas outlet of the dual-fuel main engine and the flue gas inlet of the flue gas heat exchanger.

[0014] Further, the flue gas outlet of the dual-fuel main engine is further communicated to a carbon dioxide capture unit.

[0015] Further, the cold-heat energy circulation unit further comprises a pure water heat exchange regulating valve arranged on the first branch and a flue gas heat exchange regulating valve arranged on the second branch.

[0016] Further, the second outlet of the hydrogen storage tank is communicated to a hydrogen fuel cell group.

[0017] Further, the water outlet of the electrolytic cell is communicated to the backwater inlet of the pure water unit.

[0018] Further, the cold-heat energy circulation unit further comprises a low-temperature cylinder jacket water unit and a low-temperature cylinder jacket water heat exchanger, the outlet of the low-temperature cylinder jacket water unit is communicated to the inlet of the low-temperature cylinder jacket water heat exchanger, the outlet of the low-temperature cylinder jacket water heat exchanger is communicated to the inlet of the low-temperature cylinder jacket water unit; the outlet of the circulating pump is further communicated to the circulating medium inlet of the low-temperature cylinder jacket water heat exchanger through a third branch, and the circulating medium outlet of the low-temperature cylinder jacket water heat exchanger is communicated to the circulating medium inlet of the LNG heat exchanger.

[0019] The application further provides an LNG dual-fuel power ship comprising the above-mentioned gas supply system of the LNG dual-fuel main engine.

[0020] The LNG dual-fuel main engine gas supply system provided by this invention couples the electrolysis hydrogen production unit, the exhaust gas recirculation unit, and the thermal energy circulation unit with the LNG supply unit. It supplies both natural gas and hydrogen produced from electrolysis to the dual-fuel main engine, employing mixed combustion technology to improve the thermal efficiency of the dual-fuel main engine. Simultaneously, oxygen produced from electrolysis replaces air in the dual-fuel main engine combustion. Using enriched combustion technology and exhaust gas recirculation technology, the flue gas from the dual-fuel main engine is treated into a high concentration of carbon dioxide, effectively reducing the energy consumption of the subsequent carbon dioxide capture process. Furthermore, during the operation of the LNG dual-fuel main engine gas supply system, the thermal energy circulation unit uses the LNG cold energy to cool the electrolysis hydrogen production unit and the exhaust gas recirculation unit, realizing the recovery and utilization of LNG cold energy. Further, the surplus hydrogen produced from electrolysis is converted into electricity through a hydrogen fuel cell system for daily use on board the ship. Attached Figure Description

[0021] Figure 1 is a schematic diagram of the gas supply system of the LNG dual-fuel main engine in a preferred embodiment of the present invention. Embodiments of the present invention

[0022] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0023] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0024] The directional terms such as "up," "down," "left," "right," "front," "back," "top," and "bottom" (if present) used in the specification and claims of this invention are defined by the position of the structures in the drawings and the relative positions of the structures, and are only for the clarity and convenience of expressing the technical solution. It should be understood that the use of directional terms should not limit the scope of protection claimed by this invention.

[0025] As shown in Figure 1, the gas supply system of the LNG (Liquefied Natural Gas) dual-fuel main unit provided in this embodiment of the invention includes an LNG supply unit 10, a dual-fuel main unit 20, an electrolysis hydrogen production unit 30, an exhaust gas recirculation unit 40, and a cold and heat energy circulation unit 50. The LNG supply unit 10 includes an LNG storage tank 11, a submersible pump 12, an LNG heat exchanger 13, and a buffer tank 14. The electrolysis hydrogen production unit 30 includes a pure water unit 31, a pure water heat exchanger 32, an electrolyzer 33, a hydrogen storage tank 34, and an oxygen storage tank 35. The exhaust gas recirculation unit 40 includes a flue gas heat exchanger 41. The cold and heat energy circulation unit 50 includes an expansion tank 51 and a circulation pump 52.

[0026] Specifically, the submerged pump 12 is arranged in the LNG storage tank 11, the outlet of the submerged pump 12 is communicated with the LNG inlet of the LNG heat exchanger 13, the NG outlet of the LNG heat exchanger 13 is communicated with the inlet of the buffer tank 14, and the outlet of the buffer tank 14 is communicated with the first gas inlet 21 of the dual-fuel main engine 20. Wherein, the LNG storage tank 11 is used for storing low-temperature liquid LNG, the submerged pump 12 is used for pumping the low-temperature LNG in the LNG storage tank 11, the LNG heat exchanger 13 is used for heating and vaporizing the low-temperature LNG into NG (Natural Gas, i.e. gaseous natural gas) with a suitable temperature, and the NG enters the dual-fuel main engine 20 for combustion after pressure control by the buffer tank 14.

[0027] Further, the LNG supply unit 10 further comprises a gas supply main valve 15 arranged on the pipeline between the outlet of the buffer tank 14 and the first gas inlet 21 of the dual-fuel main engine 20. The gas supply main valve 15 is used to control the amount of NG entering the dual-fuel main engine 20.

[0028] The electrolytic hydrogen production unit 10 is mainly used for electrolyzing water into hydrogen and oxygen. Wherein, the outlet of the pure water unit 31 is communicated with the pure water inlet of the pure water heat exchanger 32, and the pure water outlet of the pure water heat exchanger 32 is communicated with the water inlet of the electrolytic tank 33. The hydrogen outlet of the electrolytic tank 33 is communicated with the inlet of the hydrogen storage tank 34, the first outlet 341 of the hydrogen storage tank 34 is communicated to the pipeline between the outlet of the buffer tank 14 and the first gas inlet 21 of the dual-fuel main engine 20, and in the embodiment, the first outlet 341 of the hydrogen storage tank 34 is communicated to the pipeline between the outlet of the gas supply main valve 15 and the first gas inlet 21 of the dual-fuel main engine 20. The oxygen outlet of the electrolytic tank 33 is communicated with the inlet of the oxygen storage tank 35, and the outlet of the oxygen storage tank 35 is communicated with the second gas inlet 22 of the dual-fuel main engine 20. The pure water unit 21 is used to manufacture pure water, which is cooled by the pure water heat exchanger 22 and then enters the electrolytic tank 33 for electrolysis to generate hydrogen and oxygen, which enter the hydrogen storage tank 34 and the oxygen storage tank 35 respectively. The hydrogen in the hydrogen storage tank 34 is mixed with the NG at the outlet of the gas supply main valve 15 and then enters the dual-fuel main engine 20 for mixed combustion, effectively improving the thermal efficiency value of the dual-fuel main engine 20.

[0029] Further, the electrolytic tank 33 also has a water outlet, the water outlet of the electrolytic tank 33 is communicated with the backwater outlet of the pure water unit 31, and the excess pure water not electrolyzed by the electrolytic tank 33 returns to the pure water unit 31 through the water outlet of the electrolytic tank 33.

[0030] Further, the electrolytic hydrogen production unit 30 further comprises a hydrogen regulating valve 36 and an oxygen regulating valve 37. The hydrogen regulating valve 36 is arranged on the pipeline connected with the first outlet 341 of the hydrogen storage tank 34, i.e. the hydrogen in the hydrogen storage tank 34 enters the dual-fuel main engine 20 through the hydrogen regulating valve 36, and the hydrogen regulating valve 36 is used to regulate the amount of hydrogen discharged from the first outlet 341 of the hydrogen storage tank 34. The oxygen regulating valve 37 is arranged on the pipeline connected with the outlet of the oxygen storage tank 35, i.e. the oxygen in the oxygen storage tank 35 enters the dual-fuel main engine 20 through the oxygen regulating valve 37, and the oxygen regulating valve 37 is used to regulate the amount of oxygen discharged from the outlet of the oxygen storage tank 35.

[0031] Further, the hydrogen storage tank 34 further has a second outlet 342. The second outlet 342 of the hydrogen storage tank 34 is communicated to the hydrogen fuel cell group 70. The second outlet 342 of the hydrogen storage tank 34 is used to discharge the remaining hydrogen, and the remaining hydrogen is converted into electric energy by the hydrogen fuel cell group 70 for daily life of the ship.

[0032] The flue gas outlet 23 of the dual-fuel main engine 20 is used to discharge the burned flue gas. The flue gas outlet 23 of the dual-fuel main engine 20 is communicated to the flue gas inlet of the flue gas heat exchanger 41, and the flue gas outlet of the flue gas heat exchanger 41 is communicated to the pipeline between the outlet of the oxygen storage tank 35 and the second air inlet 22 of the dual-fuel main engine 20. In this embodiment, the flue gas outlet of the flue gas heat exchanger 41 is communicated to the pipeline between the outlet of the oxygen regulating valve 37 and the second air inlet 22 of the dual-fuel main engine 20. The flue gas heat exchanger 41 is used to cool part of the high-temperature flue gas discharged from the flue gas outlet 23 of the dual-fuel main engine 20, and the cooled flue gas is mixed with the oxygen discharged from the oxygen storage tank 35 and enters the dual-fuel main engine 20. By replacing the air in the oxygen storage tank 35 with oxygen to enter the dual-fuel main engine 20 for combustion, the dual-fuel main engine 20 uses the rich burn combustion technology and the exhaust gas recirculation technology to treat the exhaust gas of the dual-fuel main engine 20 into high-concentration carbon dioxide. Since no air is involved in this process, the production of nitrogen oxides is effectively avoided.

[0033] Further, the exhaust gas recirculation unit 40 further comprises a flue gas regulating valve 42 arranged on the pipeline between the flue gas outlet 23 of the dual-fuel main engine 20 and the flue gas inlet of the flue gas heat exchanger 41. By adjusting the opening degree of the flue gas regulating valve 42, the amount of high-temperature flue gas entering the flue gas heat exchanger 41 can be controlled.

[0034] Further, the flue gas outlet 23 of the dual-fuel main engine 20 is further communicated to the carbon dioxide capture unit 60. The carbon dioxide capture unit 60 can use the membrane separation method to capture high-concentration carbon dioxide, and then compress and store the carbon dioxide, thereby effectively reducing the energy consumption of the carbon dioxide capture process and reducing the emission of greenhouse gases.

[0035] The cold and heat energy circulation unit 50 is mainly used for recycling and reusing the cold energy in the LNG heat exchanger 13 to cool the gas supply system of the LNG dual-fuel main engine. Specifically, the outlet of the expansion water tank 51 is connected to the inlet of the circulation pump 52, the outlet of the circulation pump 52 is connected to the circulation medium inlet of the pure water heat exchanger 32 through a first branch 501, the circulation medium outlet of the pure water heat exchanger 32 is connected to the circulation medium inlet of the LNG heat exchanger 13, and the circulation medium outlet of the LNG heat exchanger 13 is connected to the pipeline between the outlet of the expansion water tank 51 and the inlet of the circulation pump 52. The outlet of the circulation pump 52 is also connected to the circulation medium inlet of the flue gas heat exchanger 41 through a second branch 502, the circulation medium outlet of the flue gas heat exchanger 41 is connected to the circulation medium inlet of the LNG heat exchanger 13, and the circulation medium outlet of the LNG heat exchanger 13 is connected to the pipeline between the outlet of the expansion water tank 51 and the inlet of the circulation pump 52.

[0036] The expansion water tank 51 and the pipeline of the cold and heat energy circulation unit 50 are provided with a circulation medium, for example, water glycol solution. The circulation medium concentrates the heat energy of the pure water heat exchanger 32 and the flue gas heat exchanger 41 to the LNG heat exchanger 13 for heat exchange with LNG, effectively recycling and utilizing the cold energy of LNG.

[0037] Further, the cold and heat energy circulation unit 50 further comprises a pure water heat exchange adjusting valve 53 and a flue gas heat exchange adjusting valve 54, the pure water heat exchange adjusting valve 53 is arranged in the first branch 501, and the flue gas heat exchange adjusting valve 54 is arranged in the second branch 502. By adjusting the valve opening of the pure water heat exchange adjusting valve 53 and the flue gas heat exchange adjusting valve 54, the amount of circulation medium entering the pure water heat exchanger 32 and the flue gas heat exchanger 41 can be controlled, and then the temperature of the pure water outlet end of the pure water heat exchanger 32 and the flue gas outlet end of the flue gas heat exchanger 41 can be controlled.

[0038] Further, the cold and heat energy circulation unit 50 further comprises a low-temperature cylinder liner water unit 55 and a low-temperature cylinder liner water heat exchanger 56. The low-temperature cylinder liner water unit 21 is part of the main engine cooling system of the ship, and the water temperature is maintained at 36℃. The outlet of the low-temperature cylinder liner water unit 55 is connected to the inlet of the low-temperature cylinder liner water heat exchanger 56, and the outlet of the low-temperature cylinder liner water heat exchanger 56 is connected to the inlet of the low-temperature cylinder liner water unit 55. The outlet of the circulation pump 52 is also connected to the circulation medium inlet of the low-temperature cylinder liner water heat exchanger 56 through a third branch 503, and the circulation medium outlet of the low-temperature cylinder liner water heat exchanger 56 is connected to the circulation medium inlet of the LNG heat exchanger 13. Since there is more cold energy in the LNG heat exchanger 13, there is still a surplus after heat exchange in the pure water heat exchanger 32 and the flue gas heat exchanger 41. By coupling the low-temperature cylinder liner water heat exchanger 56 to the cold and heat energy circulation unit 50, the cold and heat energy circulation unit 50 is part of the main engine cooling system, and the utilization rate of the cold energy in the LNG heat exchanger 13 is further improved.

[0039] The LNG dual-fuel main engine's gas supply system of this invention couples the hydrogen electrolysis unit 30, the exhaust gas recirculation unit 40, and the thermal energy recirculation unit 50 with the LNG supply unit 10. This provides both natural gas and hydrogen produced from hydrogen electrolysis to the dual-fuel main engine 20, employing mixed combustion technology to improve the thermal efficiency of the dual-fuel main engine 20. Simultaneously, oxygen produced from hydrogen electrolysis replaces air in the dual-fuel main engine 20 for combustion. Using enriched combustion technology and exhaust gas recirculation technology, the flue gas from the dual-fuel main engine 20 is treated into a high concentration of carbon dioxide, effectively reducing energy consumption in the subsequent carbon dioxide capture process. Furthermore, during the operation of the LNG dual-fuel main engine's gas supply system, the thermal energy recirculation unit 50 uses the LNG cold energy to cool the hydrogen electrolysis unit 30 and the exhaust gas recirculation unit 40, achieving the recovery and utilization of LNG cold energy. Further, the residual hydrogen produced from hydrogen electrolysis is converted into electricity through a hydrogen fuel cell system 70 for daily use on the ship.

[0040] The present invention also relates to an LNG dual-fuel powered vessel, including the gas supply system of the aforementioned LNG dual-fuel main engine. Other structures of the LNG dual-fuel powered vessel are well known in the art and will not be described in detail here.

[0041] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A gas supply system for an LNG dual-fuel main engine, characterized in that, The system includes an LNG supply unit (10), a dual-fuel main engine (20), an electrolysis hydrogen production unit (30), a waste gas recirculation unit (40), and a cold and heat energy circulation unit (50); the LNG supply unit (10) includes an LNG storage tank (11), a submersible pump (12), an LNG heat exchanger (13), and a buffer tank (14); the electrolysis hydrogen production unit (30) includes a pure water unit (31), a pure water heat exchanger (32), an electrolyzer (33), a hydrogen storage tank (34), and an oxygen storage tank (35); the waste gas recirculation unit (40) includes a flue gas heat exchanger (41); and the cold and heat energy circulation unit (50) includes an expansion tank (51) and a circulation pump (52). The submersible pump (12) is installed inside the LNG storage tank (11). The outlet of the submersible pump (12) is connected to the LNG inlet of the LNG heat exchanger (13). The LNG outlet of the LNG heat exchanger (13) is connected to the inlet of the buffer tank (14). The outlet of the buffer tank (14) is connected to the first air inlet (21) of the dual-fuel main engine (20). The outlet of the pure water unit (31) is connected to the pure water inlet of the pure water heat exchanger (32), and the pure water outlet of the pure water heat exchanger (32) is connected to the inlet of the electrolytic cell (33); the hydrogen outlet of the electrolytic cell (33) is connected to the inlet of the hydrogen storage tank (34), and the first outlet (341) of the hydrogen storage tank (34) is connected to the pipeline between the outlet of the buffer tank (14) and the first air inlet (21) of the dual-fuel main engine (20); the oxygen outlet of the electrolytic cell (33) is connected to the inlet of the oxygen storage tank (35), and the outlet of the oxygen storage tank (35) is connected to the second air inlet (22) of the dual-fuel main engine (20); The flue gas outlet (23) of the dual-fuel main unit (20) is connected to the flue gas inlet of the flue gas heat exchanger (41), and the flue gas outlet of the flue gas heat exchanger (41) is connected to a pipeline between the outlet of the oxygen storage tank (35) and the second air inlet (22) of the dual-fuel main unit (20); and The outlet of the expansion tank (51) is connected to the inlet of the circulating pump (52). The outlet of the circulating pump (52) is connected to the circulating medium inlet of the pure water heat exchanger (32) through the first branch (501). The circulating medium outlet of the pure water heat exchanger (32) is connected to the circulating medium inlet of the LNG heat exchanger (13). The outlet of the circulating pump (52) is also connected to the circulating medium inlet of the flue gas heat exchanger (41) through the second branch (502). The circulating medium outlet of the flue gas heat exchanger (41) is connected to the circulating medium inlet of the LNG heat exchanger (13). The circulating medium outlet of the LNG heat exchanger (13) is connected to the pipeline between the outlet of the expansion tank (51) and the inlet of the circulating pump (52).

2. The gas supply system for the LNG dual-fuel main engine according to claim 1, characterized in that, The LNG supply unit (10) also includes a main gas supply valve (15), which is located on the pipeline between the outlet of the buffer tank (14) and the first gas inlet (21) of the dual-fuel main engine (20); the first outlet (341) of the hydrogen storage tank (34) is connected to the pipeline between the outlet of the main gas supply valve (15) and the first gas inlet (21) of the dual-fuel main engine (20).

3. The gas supply system for the LNG dual-fuel main engine according to claim 2, characterized in that, The electrolytic hydrogen production unit (30) further includes a hydrogen regulating valve (36) and an oxygen regulating valve (37). The hydrogen regulating valve (36) is installed on a pipeline connected to the first outlet (341) of the hydrogen storage tank (34), and the oxygen regulating valve (37) is installed on a pipeline connected to the outlet of the oxygen storage tank (35). The flue gas outlet of the flue gas heat exchanger (41) is connected to the pipeline between the outlet of the oxygen regulating valve (37) and the second air inlet (22) of the dual-fuel main engine (20).

4. The gas supply system for the LNG dual-fuel main engine according to claim 1, characterized in that, The exhaust gas recirculation unit (40) also includes a flue gas regulating valve (42), which is located on the pipeline between the flue gas outlet (23) of the dual-fuel main unit (20) and the flue gas inlet of the flue gas heat exchanger (41).

5. The gas supply system for the LNG dual-fuel main engine according to claim 4, characterized in that, The flue gas outlet (23) of the dual-fuel main unit (20) is also connected to the carbon dioxide capture unit (60).

6. The gas supply system for the LNG dual-fuel main engine according to claim 1, characterized in that, The cold and heat energy circulation unit (50) also includes a pure water heat exchange regulating valve (53) and a flue gas heat exchange regulating valve (54). The pure water heat exchange regulating valve (53) is located in the first branch (501), and the flue gas heat exchange regulating valve (54) is located in the second branch (502).

7. The gas supply system for the LNG dual-fuel main engine according to claim 1, characterized in that, The second outlet (342) of the hydrogen storage tank (34) is connected to the hydrogen fuel cell stack (70).

8. The gas supply system for the LNG dual-fuel main engine according to claim 1, characterized in that, The outlet of the electrolytic cell (33) is connected to the return outlet of the pure water unit (31).

9. The gas supply system for the LNG dual-fuel main engine according to claim 1, characterized in that, The cold and heat energy circulation unit (50) also includes a low-temperature cylinder liner water unit (55) and a low-temperature cylinder liner water heat exchanger (56). The outlet of the low-temperature cylinder liner water unit (55) is connected to the inlet of the low-temperature cylinder liner water heat exchanger (56), and the outlet of the low-temperature cylinder liner water heat exchanger (56) is connected to the inlet of the low-temperature cylinder liner water unit (55). The outlet of the circulation pump (52) is also connected to the circulation medium inlet of the low-temperature cylinder liner water heat exchanger (56) through a third branch (503), and the circulation medium outlet of the low-temperature cylinder liner water heat exchanger (56) is connected to the circulation medium inlet of the LNG heat exchanger (13).

10. An LNG dual-fuel powered ship, characterized in that, The gas supply system includes the LNG dual-fuel main engine as described in any one of claims 1 to 9.

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