Marine dual-fuel methanol supply system and method

Abstract

The invention discloses a marine dual-fuel methanol supply system and method, the marine dual-fuel methanol supply system comprises a daily cabin, a methanol supply system, a valve group control unit, a nitrogen unit and an ethylene glycol water unit, and the daily cabin is used for providing, storing and recycling methanol fuel; the methanol supply system is used for pressurizing, heating and filtering methanol liquid; the valve group control unit is used for controlling the supply quantity of fuel for conveying the dual-fuel methanol engine; the nitrogen unit is used for tightness detection and purging; the ethylene glycol water unit is used for heating or cooling methanol liquid. According to the system and the method, the methanol gas generated by heating and pressurizing, the methanol liquid and nitrogen which are subjected to purging backflow and the methanol liquid which is not used by the dual-fuel methanol engine and contains a small amount of fuel oil are recycled, so that the waste of methanol fuel is reduced. The system and the method have the advantages of being simple in principle, safe, reliable, excellent in performance, simple in structure and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel supply equipment, and in particular to a marine dual-fuel methanol supply system and method. Background Art

[0002] In the marine industry, reducing global CO2 and greenhouse gas emissions, while also addressing local emissions of nitrogen oxides, sulfur dioxide and particulate matter has become a hot topic in the coming years. The IMO has set a target to reduce total greenhouse gas emissions from international shipping by at least 50% by 2050 compared to 2008 levels. In addition, by 2030, the target has been set to reduce carbon intensity by 40%.

[0003] With the increasing global attention to environmental protection and the increasing pressure to reduce greenhouse gas emissions, green shipping is imperative, which also means that no matter how the market changes, orders for various alternative fuel ships will increase and become a major trend in the future new shipbuilding market. At present, the methanol fuel-powered ship industry is facing unprecedented development opportunities. From market demand, technical preparation, and supporting supply, the entire industry chain is showing a booming development trend.

[0004] Methanol is a transparent liquid, an organic water-soluble chemical substance that is easily biodegradable. As a sulfur-free, low-carbon fuel, the biggest advantage of methanol is that it can be stored at room temperature, is easy to transport, and green methanol can be produced on a large scale. It is a new low-carbon alternative fuel for ships favored by the market.

[0005] Since methanol has a low calorific value, it needs fuel to ignite. The methanol liquid containing a small amount of fuel that is not used by the dual-fuel methanol engine will contaminate the pure methanol after reflux, resulting in a waste of methanol fuel. In addition, methanol is volatile, and the methanol liquid will produce gas after being pressurized and heated, affecting the safety of the system.

[0006] In view of the above, it is necessary to propose a marine dual-fuel methanol supply system and method to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects in the prior art and provide a marine dual-fuel methanol supply system and method.

[0008] To achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a marine dual-fuel methanol supply system, comprising: a daily tank, a methanol supply system, a valve group control unit, and an ethylene glycol water unit; a container for classified storage of methanol raw materials is formed in the daily tank; the daily tank provides fuel to the dual-fuel methanol engine through the methanol supply system and the valve group control unit; The daily cabin includes a return cabin and a fuel cabin. The return cabin collects and separates the methanol liquid containing fuel and sends the methanol into the fuel cabin. The fuel cabin supplies the dual-fuel methanol engine. The methanol supply system includes a primary booster section, a storage section, a secondary booster section, and a glycol water unit to exchange heat for materials in the two booster sections respectively; The valve group control unit is connected between the methanol supply system and the dual-fuel methanol engine to control accurate feeding; The dual-fuel methanol engine is provided with a recovery pipe connected to the return cabin; the first-stage booster unit, storage unit, and valve group control unit are all provided with independent discharge pipelines connected to the fuel tank.

[0009] Furthermore, the first-stage boosting unit is provided with an inlet valve and a low-pressure methanol pump, the upstream of the inlet valve is connected to the fuel tank, the downstream of the inlet valve is connected to the low-pressure methanol pump, and the output end of the low-pressure methanol pump is connected to the liquid inlet end of the storage unit; a first discharge pipeline connected to the fuel tank is provided between the inlet valve and the low-pressure methanol pump, and a first control valve is provided on the first discharge pipeline.

[0010] Furthermore, the low-pressure methanol pump is provided with a first heat exchanger in parallel, the upstream of the first heat exchanger is connected to the outlet end of the low-pressure methanol pump, the downstream of the first heat exchanger is provided with a first pressure control valve, and the downstream of the first pressure control valve is connected to the inlet end of the low-pressure methanol pump.

[0011] Furthermore, the storage part includes a mixing barrel, which is provided with a liquid inlet end, a liquid outlet end, a reflux end, and a pressure relief end. A second discharge pipeline is connected between the pressure relief end and the fuel tank, and a fourth control valve and a safety valve are provided on the second discharge pipeline.

[0012] Furthermore, the secondary boosting section is provided with a high-pressure methanol pump, a second heat exchanger, and a filter assembly. The inlet end of the high-pressure methanol pump is connected to the liquid outlet end of the mixing barrel, and the outlet end is connected to the second heat exchanger. A filter assembly is provided downstream of the second heat exchanger. The outlet end of the filter assembly is connected to the valve group control unit. A branch pipe is provided between the filter assembly and the valve group control unit. The branch pipe is connected to the reflux end of the mixing barrel, and a second pressure control valve is provided on the branch pipe.

[0013] Furthermore, the filter assembly includes a first fine filter and a second fine filter arranged in parallel.

[0014] Furthermore, the valve group control unit includes an outlet valve, the upstream of the outlet valve is connected to the filter component and the downstream is connected to the dual-fuel methanol engine. A third discharge pipeline connected to the fuel tank is also provided upstream of the outlet valve, and a second control valve is provided on the third discharge pipeline.

[0015] Furthermore, the ethylene glycol water unit includes ethylene glycol water inlet and outlet valves, which are respectively provided with ethylene glycol circulation loops connected to the first heat exchanger and the second heat exchanger, and the ethylene glycol circulation loop connected to the second heat exchanger is provided with a temperature control valve.

[0016] Furthermore, it also includes a nitrogen unit, which is connected to the mixing barrel and the downstream of the outlet valve through a nitrogen pipeline.

[0017] A control method for a marine dual-fuel methanol supply system, including a pressure leakage test process, a start-up and operation process, a shutdown process, and a purge process; The pressure leakage test process: close the inlet valve and the outlet valve, open the first control valve, the second control valve, and the nitrogen valve to fill the entire pipeline with nitrogen; close the first control valve, the second control valve, and the nitrogen valve, and observe the nitrogen pressure drop of the methanol supply system. After the test is successful, the system enters the vehicle standby state; Startup and operation process: open the inlet valve, glycol water inlet and outlet valves in sequence, open the second control valve, and methanol will circulate and flow into the daily tank. When the fuel meets the temperature, pressure and flow rate of the dual-fuel methanol engine fuel, open the outlet valve; open the second pressure control valve to maintain the stability of the fuel pressure in the methanol supply system; open the third control valve, and the methanol gas pressure will exceed the set value of the safety valve and flow into the fuel tank; Parking process: close the inlet valve, outlet valve, first control valve, and second control valve, the pipelines in the system are filled with methanol fuel, and the system is ready to start at any time to supply methanol to the engine again; Purge process: open the nitrogen valve to allow nitrogen to enter the system, close the third control valve, open the first and second control valves to blow the methanol in the pipeline back to the fuel tank, open the third control valve to blow the methanol liquid containing a small amount of fuel that is not used by the dual-fuel methanol engine into the return tank, and the nitrogen will remain in the pipeline; if the system is restarted, the above process will be repeated, starting from the pressure leak test process.

[0018] The advantages and beneficial effects of the present invention are as follows: the present invention provides a marine dual-fuel methanol supply system and method, comprising a daily tank, a methanol supply system, a valve group control unit, a nitrogen unit, and an ethylene glycol water unit, wherein the daily tank is used to provide, store and recover methanol fuel; the methanol supply system pressurizes, heats and filters the methanol liquid; the valve group control unit is used to control the supply amount of the dual-fuel methanol engine fuel; the nitrogen unit is used for tightness detection and purging; the ethylene glycol water unit is used to heat or cool the methanol liquid. The system and method described in the present application recycles the methanol gas generated by heating and pressurization, the methanol liquid and nitrogen purged and refluxed, and the methanol liquid containing a small amount of fuel that is not used by the dual-fuel methanol engine, thereby reducing the waste of methanol fuel. Moreover, the system and method described in the present application have the characteristics of simple principle, safety and reliability, superior performance, and simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a dual-fuel methanol supply system for a ship of the present invention; In the figure: A, daily cabin; B, methanol supply system; C, valve group control unit; D, nitrogen unit; E, glycol water unit; 1, return cabin; 2, fuel tank; 3, inlet valve; 4, first control valve; 5, first pressure control valve; 6, low-pressure methanol pump; 7, first heat exchanger; 8, glycol water inlet and outlet valves; 9, second heat exchanger; 10, temperature control valve; 11, first fine filter; 12, second fine filter; 13, second control valve; 14, outlet valve; 15, Dual-fuel methanol engine; 16. third control valve; 17. second pressure control valve; 18. high-pressure methanol pump; 19. mixing barrel; 20. nitrogen valve; 21. fourth control valve; 22. safety valve; 23. first-stage boosting section; 24. storage section; 25. second-stage boosting section; 26. recovery pipe; 27. liquid inlet end; 28. first discharge pipeline; 29. ​​liquid outlet end; 30. reflux end; 31. pressure relief end; 32. second discharge pipeline; 33. branch pipe; 34. third discharge pipeline. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0021] like Figure 1As shown, the present application provides a schematic diagram of the structure of a dual-fuel methanol supply system for ships. The system includes a daily tank A, a methanol supply system B, a valve group control unit C, a nitrogen unit D, and an ethylene glycol water unit E, wherein the daily tank A is used to provide, store and recover methanol fuel; the methanol supply system B pressurizes, heats and filters the methanol liquid; the valve group control unit C is used to control the supply amount of the dual-fuel methanol engine 15; the nitrogen unit D is used for tightness detection and purging; and the ethylene glycol water unit E is used to heat or cool the methanol liquid.

[0022] The daily tank A includes a return tank 1 and a fuel tank 2. The return tank 1 is used to collect methanol liquid containing a small amount of fuel that is not used by the dual-fuel methanol engine 15. After gravity sedimentation, the methanol liquid returns to the fuel tank 2; the fuel tank 2 is used to provide and store methanol. The fuel tank 2 recovers the heated and pressurized methanol gas and the purged and returned methanol fuel and nitrogen; nitrogen is used as an inert gas protection container in the daily tank A; the daily tank A is equipped with a discharge port to maintain the stability of the container pressure.

[0023] The methanol supply system B is connected to the downstream of the daily tank A, and includes an inlet valve 3, a low-pressure methanol pump 6, a mixing barrel 19, a high-pressure methanol pump 18, a second heat exchanger 9 and a first fine filter 11, and a second fine filter 12, which are connected in series in sequence, and are used to pressurize, heat and filter the methanol liquid, and send the fuel to the valve group control unit C; the inlet valve 3 is connected to the daily tank A, and is used to transport and block the supply of fuel; the low-pressure methanol pump 6 extracts the methanol fuel from the daily tank A and performs a primary pressurization; the mixing barrel 19 is used to store the methanol gas and liquid after pressurization by the low-pressure methanol pump 6 and heat exchange by the first heat exchanger 7; the high-pressure methanol pump 18 is used to extract the fuel from the mixing barrel 19 and perform a secondary pressurization on the material to meet the pressure of the engine fuel; the second heat exchanger 9 is used to heat or cool the fuel to meet the temperature of the engine fuel; the first fine filter 11 and the second fine filter 12 are used in a standby manner, and are used to filter particles in the fuel that are easy to damage the engine to ensure the purity of the fuel.

[0024] The methanol supply system B includes a first heat exchanger 7, one end of which is connected between the low-pressure methanol pump 6 and the mixing barrel 19, and the other end is connected to the upstream of the first pressure control valve 5 through a bypass line. Heating or cooling the fuel on the branch line can make temperature control easier.

[0025] The methanol supply system B includes a first pressure control valve 5 and a second pressure control valve 17; one end of the first pressure control valve 5 is connected to the downstream of the first heat exchanger 7, and the other end is connected between the inlet valve 3 and the low-pressure methanol pump 6. When the output pressure of the low-pressure methanol pump 6 exceeds the set value of the first pressure control valve 5, the methanol fuel is automatically refluxed to the upstream of the low-pressure methanol pump 6; one end of the second pressure control valve 17 is connected to the mixing barrel 19, and the other end is connected to the first fine filter 11, between the second fine filter 12 and the valve group control unit C. When the delivered pressure exceeds the set value of the second pressure control valve 17, the methanol fuel is automatically refluxed to the mixing barrel 19.

[0026] The upstream of the fourth control valve 21 of the methanol supply system B is connected to the mixing barrel 19, the upstream of the safety valve 22 is connected to the fourth control valve 21, and the downstream of the safety valve 22 is connected to the return capsule 2. During the startup and operation of the dual-fuel methanol engine 15, the fourth control valve 21 is opened. When the methanol gas pressure exceeds the set value of the safety valve 22, it will automatically flow back to the return capsule 2.

[0027] The valve group control unit C is connected to the downstream of the methanol supply system B, and is used to control the supply amount of methanol fuel, including an outlet valve 14 and a second control valve 13; the outlet valve 14 is connected to the first fine filter 11 and the second fine filter 12 upstream, and is connected to the dual-fuel methanol engine 15 downstream, and is used to transport and block the supply of fuel; the second control valve 13 is used to reflux methanol to the return capsule 2 during the pressure leakage test process and the purging process.

[0028] The glycol water inlet and outlet valves 8 are connected to the first heat exchanger 7 and the second heat exchanger 9 for heat exchange with the methanol fuel, and the glycol water supply pipeline is a single-wall pipeline. A temperature control valve 10 is connected downstream of the second heat exchanger 9 for accurately controlling the temperature of the input methanol fuel.

[0029] After the nitrogen gas flows in through the nitrogen valve 20, it is divided into two paths, one of which is connected to the mixing barrel 19 of the methanol supply system B, and the other is connected downstream of the outlet valve 14. The nitrogen supply pipeline is a single-wall pipeline.

[0030] The daily tank A, methanol supply system B and valve group control unit C are arranged together in the fuel preparation room. The methanol fuel supply pipelines between the daily tank A and the methanol supply system B and between the methanol supply system B and the valve group control unit C are all single-wall pipelines.

[0031] The methanol fuel supply pipeline between the valve group control unit C and the dual-fuel methanol engine 15 is a double-wall pipeline.

[0032] As a further technical solution of this patent, a dual-fuel methanol supply method is provided, including a pressure leak test process, a startup and operation process, a shutdown process and a purge process.

[0033] Pressure leakage test process: close the inlet valve 3 and the outlet valve 14, open the first control valve 4, the second control valve 13, and the nitrogen valve 20, fill the entire pipeline with nitrogen, close the first control valve 4, the second control valve 13, and the nitrogen valve 20, observe the nitrogen pressure drop of the methanol supply system B, and after the test is successful, the system enters the vehicle standby state.

[0034] Start-up and operation process: open the inlet valve 3, the ethylene glycol water inlet and outlet valves 8 in turn, open the second control valve 13, and the methanol will circulate and flow into the daily tank A. When the fuel meets the temperature, pressure and flow rate of the dual-fuel methanol engine 15, open the outlet valve 14; open the second pressure control valve 17 to keep the fuel pressure in the methanol supply system B stable; open the third control valve 21, and the methanol gas pressure will exceed the set value of the safety valve 22 and flow into the fuel tank 2.

[0035] Parking process: close the inlet valve 3, the outlet valve 14, the first control valve 4, and the second control valve 13. The pipelines in the system are filled with methanol fuel, and the system is ready to start at any time to supply methanol to the engine again.

[0036] Purging process: Open the nitrogen valve 20, nitrogen enters the system, close the third control valve 21, open the first control valve 4, the second control valve 13 to blow the methanol in the pipeline back to the fuel tank 2, open the third control valve 16 to blow the methanol liquid containing a small amount of fuel that is not used by the dual-fuel methanol engine 15 into the return tank 1, and the nitrogen will remain in the pipeline. If the system is restarted, the above process will be repeated, starting from the pressure leak test process.

[0037] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects: During the startup and operation process, the generated methanol gas flows back into the fuel tank 2 through the safety valve 22, reducing the damage caused by the methanol gas to the pipeline, making the system safe, reliable and durable.

[0038] The methanol liquid containing a small amount of fuel that is not used by the dual-fuel methanol engine 15 is blown into the return tank 1 and returned to the fuel tank 2 through gravity sedimentation, thereby ensuring the purity of the methanol liquid in the fuel tank 2, recycling it and saving energy.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A marine dual-fuel methanol supply system, characterized in that: include: A daily cabin (A), a methanol supply system (B), a valve group control unit (C), and an ethylene glycol water unit (E); a container for storing methanol raw materials in a classified manner is formed in the daily cabin (A); the daily cabin (A) supplies fuel to the dual-fuel methanol engine (15) through the methanol supply system (B) and the valve group control unit (C); The daily cabin (A) comprises a return cabin (1) and a fuel cabin (2). The return cabin (1) collects and separates methanol liquid containing fuel and delivers the methanol to the fuel cabin (2). The fuel cabin (2) supplies fuel to the dual-fuel methanol engine (15). The methanol supply system (B) comprises a primary boosting section (23), a storage section (24), a secondary boosting section (25), and an ethylene glycol water unit (E) for performing heat exchange on materials in the two boosting sections respectively; The valve group control unit (C) is connected between the methanol supply system (B) and the dual-fuel methanol engine (15) to control accurate supply; The dual-fuel methanol engine (15) is provided with a recovery pipe (26) connected to the return capsule (1); the first-stage booster unit (23), the storage unit (24), and the valve group control unit (C) are all provided with independent discharge pipelines connected to the fuel tank (2).

2. A marine dual-fuel methanol supply system according to claim 1, characterized in that: The first-stage booster section (23) is provided with an inlet valve (3) and a low-pressure methanol pump (6); the upstream of the inlet valve (3) is connected to the fuel tank (2); the downstream of the inlet valve (3) is connected to the low-pressure methanol pump (6); the output end of the low-pressure methanol pump (6) is connected to the liquid inlet end (27) of the storage section (24); a first discharge pipeline (28) connected to the fuel tank (2) is provided between the inlet valve (3) and the low-pressure methanol pump (6); and a first control valve (4) is provided on the first discharge pipeline (28).

3. A marine dual-fuel methanol supply system according to claim 2, characterized in that: The low-pressure methanol pump (6) is provided with a first heat exchanger (7) in parallel, the upstream of the first heat exchanger (7) is connected to the outlet end of the low-pressure methanol pump (6), and the downstream of the first heat exchanger (7) is provided with a first pressure control valve (5), and the downstream of the first pressure control valve (5) is connected to the inlet end of the low-pressure methanol pump (6).

4. A marine dual-fuel methanol supply system according to claim 3, characterized in that: The storage section (24) comprises a mixing barrel (19), the mixing barrel (19) being provided with a liquid inlet end (27), a liquid outlet end (29), a reflux end (30), and a pressure relief end (31), a second relief pipeline (32) being connected between the pressure relief end (31) and the fuel tank (2), and a fourth control valve (21) and a safety valve (22) being provided on the second relief pipeline (32).

5. A marine dual-fuel methanol supply system according to claim 4, characterized in that: The secondary boosting section (25) is provided with a high-pressure methanol pump (18), a second heat exchanger (9), and a filter assembly. The inlet end of the high-pressure methanol pump (18) is connected to the liquid outlet end (29) of the mixing barrel (19), and the outlet end is connected to the second heat exchanger (9). The filter assembly is connected downstream of the second heat exchanger (9). The outlet end of the filter assembly is connected to the valve group control unit (C). A branch pipe (33) is provided between the filter assembly and the valve group control unit (C). The branch pipe (33) is connected to the reflux end (30) of the mixing barrel (19). The branch pipe (33) is provided with a second pressure control valve (17).

6. A marine dual-fuel methanol supply system according to claim 5, characterized in that: The filter assembly comprises a first fine filter (11) and a second fine filter (12) which are arranged in parallel.

7. A marine dual-fuel methanol supply system according to claim 5 or 6, characterized in that: The valve group control unit (C) comprises an outlet valve (14), wherein the outlet valve (14) is connected to a filter assembly upstream and to a dual-fuel methanol engine (15) downstream, and a third discharge pipeline (34) connected to a fuel tank (2) is also provided upstream of the outlet valve (14), and a second control valve (13) is provided on the third discharge pipeline (34).

8. A marine dual-fuel methanol supply system according to claim 5, characterized in that: The ethylene glycol water unit (E) comprises ethylene glycol water inlet and outlet valves (8), each of which is provided with an ethylene glycol circulation loop connected to the first heat exchanger (7) and the second heat exchanger (9), and a temperature control valve (10) is provided on the ethylene glycol circulation loop connected to the second heat exchanger (9).

9. A marine dual-fuel methanol supply system according to claim 8, characterized in that: The invention also comprises a nitrogen unit (D), which is connected to the mixing tank (19) and the downstream of the outlet valve (14) through nitrogen pipelines.

10. The control method of a marine dual-fuel methanol supply system according to claim 9, characterized in that: Including pressure leak test process, startup and operation process, shutdown process, and purge process; The pressure leakage test process is as follows: closing the inlet valve (3) and the outlet valve (14), opening the first control valve (4), the second control valve (13), and the nitrogen valve (20), so that the nitrogen fills the entire pipeline; closing the first control valve (4), the second control valve (13), and the nitrogen valve (20), observing the nitrogen pressure drop of the methanol supply system (B), and after the test is successful, the system enters a vehicle standby state; Start-up and operation process: open the inlet valve (3), the glycol water inlet and outlet valves (8) in sequence, open the second control valve (13), and allow methanol to circulate and flow into the daily tank (A). When the fuel meets the temperature, pressure and flow rate of the dual-fuel methanol engine (15), open the outlet valve (14); open the second pressure control valve (17) to maintain the stability of the fuel pressure in the methanol supply system (B); open the third control valve (16), and when the methanol gas pressure exceeds the set value of the safety valve (22), it will flow into the fuel tank (2); Stop process: close the inlet valve (3), the outlet valve (14), the first control valve (4), and the second control valve (13); the pipelines in the system are filled with methanol fuel, and the system is ready to start at any time to supply methanol to the engine again; Purging process: open the nitrogen valve (20), nitrogen enters the system, close the third control valve (16), open the first control valve (4), and the second control valve (13) to blow the methanol in the pipeline back to the fuel tank (2), open the third control valve (16) and blow the methanol liquid containing a small amount of fuel that is not used by the dual-fuel methanol engine (15) into the return tank (1), and the nitrogen will remain in the pipeline; if the system is restarted, the above process will be repeated, starting from the pressure leak test process.

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