Fuel supply and safety system for marine ammonia fuel engines

Abstract

The utility model discloses a fuel supply and security system for a marine ammonia fuel engine, including a liquid ammonia fuel tank, a nitrogen tank, a fuel supply skid unit, an ammonia capture unit, a high-pressure common rail double-wall pipe, a central control unit and a collection tank. The utility model significantly improves the safety and stability of the marine ammonia fuel engine. The fuel supply skid unit realizes high-coverage high-pressure purge of ammonia accumulation at the bottom of the fuel supply skid unit box and high-efficiency discharge and replacement of gaseous ammonia. The nitrogen capture unit can not only process pure ammonia vapor volatilized from the liquid ammonia storage tank, but also process ammonia-nitrogen mixed gas sent from the fuel supply skid and the collection tank, effectively increasing the working margin and processing capacity of the ammonia capture unit.

Description

Technical Field

[0001] The utility model relates to a new energy engine, in particular to a fuel supply and security system capable of realizing ammonia fuel leakage detection and zero-contact circulation processing of an ammonia fuel engine, belonging to the technical field of marine new energy engines. Background Art

[0002] Compared with traditional fossil fuels, ammonia fuel has zero carbon emissions. Against the backdrop of increasingly stringent international emission regulations, it is foreseeable that ammonia fuel engines will be widely used in the field of marine engines in the future. At present, major marine engine manufacturers around the world are actively promoting the research and development of ammonia fuel engines to seize the market for marine ammonia fuel engines. Since ammonia fuel engines use liquid ammonia as the engine intake, the required intake pressure and temperature are relatively high, making fuel supply more difficult; at the same time, ammonia has certain toxicity and high volatility, and its safety during use is also crucial. Therefore, there is an urgent need to provide a fuel supply and security system for marine ammonia fuel engines to solve the problems of liquid ammonia supply and operational safety. Utility Model Content

[0003] The utility model aims to provide a fuel supply and safety system for a marine ammonia fuel engine, which ensures the stability of the ammonia fuel supply pressure and significantly improves the safety and stability of the marine ammonia fuel engine.

[0004] The utility model is realized through the following technical solutions:

[0005] A fuel supply and safety system for a marine ammonia fuel engine, comprising a liquid ammonia fuel tank, a nitrogen tank, a fuel supply skid unit, an ammonia capture unit, a high-pressure common rail double-wall pipe, a central control unit and a collection tank, wherein one end of a main fuel pipe extends into the liquid ammonia fuel tank, and the other end of the main fuel pipe first passes through a first electromagnetic three-way valve directly to an ac end, and then passes through a first booster pump, an electric heater, a second electromagnetic three-way valve directly to an ac end, a secondary booster pump, an inner pipe of a high-pressure common rail double-wall pipe, and a third electromagnetic three-way valve directly to an ac end of the fuel supply skid unit in sequence, and then leads to the marine ammonia fuel engine, a bypass b end of the third electromagnetic three-way valve is connected to a first two-way valve and a pressure reducer in sequence through a branch pipe, and then leads to a bypass b end of the second electromagnetic three-way valve, and pressure regulating valves are connected in parallel at both ends of the first booster pump;

[0006] The bypass b end of the first nitrogen solenoid three-way valve is vertically connected to one end of the outer tube of the high-pressure common rail double-wall tube through a nitrogen delivery pipe. The liquid ammonia collecting pipe at one end of the outer tube of the high-pressure common rail double-wall tube is connected to the collection tank through the first solenoid two-way valve. The reflux pipe at the bottom of the collection tank passes through the second solenoid two-way valve, the reflux booster pump in the fuel supply skid-mounted unit, and the fourth solenoid three-way valve directly connected to the ac end, and then connected to the direct ac end of the second solenoid three-way valve and the input end of the secondary booster pump through a connecting pipe in sequence; the liquid ammonia collecting pipe connected to the bypass b end of the fourth solenoid three-way valve is connected to the liquid ammonia fuel tank through a cooling compressor; nitrogen The nitrogen delivery pipe at the output end of the tank is connected to the input end of the first booster pump in sequence through the first nitrogen electromagnetic three-way valve directly connected to the ac end, the second nitrogen electromagnetic three-way valve directly connected to the ac end, and the first electromagnetic three-way valve bypass bc end; the output pipe of the fan is connected to the lower part of the fuel supply skid-mounted unit box in sequence through the first air supply electromagnetic three-way valve directly connected to the ac end, the second air supply electromagnetic three-way valve directly connected to the ac end and the first air supply pipe, and the second air supply electromagnetic three-way valve bypass b end is connected to the lower part of the fuel supply skid-mounted unit box through the second air supply pipe; the manifold at the bottom of the fuel supply skid-mounted unit box is connected to the lower part of the collection tank through the third electromagnetic two-way valve;

[0007] The first water pump of the ammonia capture unit of the security system is connected to one end of the spray chamber through a water delivery pipe, the bottom of the spray chamber is connected to the upper end of the liquid accumulation chamber through the first water delivery two-way solenoid valve, the water delivery three-way solenoid valve at the lower end of the liquid accumulation chamber is directly connected to the upper side of the heat exchanger input A end through the hot air pipe connected to the exhaust pipe, and the delivery pipe on the upper side of the heat exchanger output B end is connected to the liquid ammonia fuel tank through a liquid ammonia delivery pump; the connecting pipe on the lower side of the heat exchanger input A end and the connecting pipe on the lower side of the heat exchanger output B end are respectively connected to the two ends of the dehydrator; the liquid delivery pipe connected to the bypass b end of the water delivery three-way solenoid valve is connected to one side of the spray chamber through the second water pump, and the gas delivery pipe on the other side of the spray chamber is divided into two routes, which are respectively connected to the upper part of the fuel supply skid-mounted unit box through the second two-way solenoid valve and the two-way valve;

[0008] One end of a safety pipeline is connected to the upper end of the liquid ammonia fuel tank through a first safety valve, and the other end of a safety pipeline is connected to one side of the spray chamber; one end of another safety pipeline is connected to the upper end of the collection tank through a second safety valve, and the other end of another safety pipeline is connected to the other side of the spray chamber;

[0009] The safety pipeline between the third electromagnetic three-way valve direct-through ac end and the marine ammonia fuel engine connection end is connected to the upper part of the collection tank through the third safety valve;

[0010] The signal lines of the central control unit are respectively connected to the control ends of each two-way solenoid valve and each three-way solenoid valve.

[0011] The purpose of the utility model can be further achieved by the following technical measures.

[0012] Furthermore, an upper level gauge and a lower level gauge are provided at the middle and lower parts of the liquid accumulation chamber, and an upper level gauge and a lower level gauge are provided at the middle and lower parts of the collecting tank, respectively; the liquid accumulation chamber is also connected to an ammonia concentration gauge in the liquid accumulation chamber, the upper part of the fuel supply skid-mounted unit box is connected to an ammonia concentration gauge in the box, the bottom of the fuel supply skid-mounted unit box is connected to a box level gauge, and the manifold is connected to a manifold level gauge; two safety pipelines are connected to a first flow meter and a second flow meter, respectively; first pressure sensors are connected to the main fuel pipes at both ends of the electric heater, respectively A second pressure sensor is connected to the pipeline at the output end of the pressure reducer, a third pressure sensor is connected to the main fuel pipe connecting the secondary booster pump and the inner tube of the high-pressure common rail double-walled tube, a fourth pressure sensor is connected to the pipeline connecting the reflux booster pump and the direct-through ac end of the fourth electromagnetic three-way valve, a first safety pipeline flow meter and a second safety pipeline flow meter are connected to the safety pipelines connected to both sides of the spray chamber respectively; an outer tube liquid level meter is connected to the outer tube of the high-pressure common rail double-walled tube, and a liquid ammonia collecting pipe is connected to the collecting pipe liquid level meter.

[0013] Furthermore, the pressure range of the first booster pump outputting liquid ammonia is: 2.7~3.0Mpa; the pressure range of the secondary booster pump outputting liquid ammonia is: 7.0~8.5Mpa. The electric heater heats the liquid ammonia in the temperature range of 25~45℃, and the heating power is 50kW. The heat exchange power of the input A end of the heat exchanger is 0.5kW, the cooling power of the output B end of the heat exchanger is 1kW, and the temperature of the liquid ammonia output at the output B end of the heat exchanger is -32~-34℃. The dehydrator is filled with alkaline desiccant.

[0014] The port of the first air supply pipe extending into the bottom of the side wall of the fuel supply skid-mounted unit case is a flat-tongue type port, and the ratio of the inner width A1 of the flat-tongue type port to the inner diameter A2 of the first air supply pipe is: A1 / A2=1.4:1, and the ratio of the inner height B2 of the flat-tongue type port to the inner diameter A2 of the first air supply pipe is: B2 / A2=0.1:1; the second air supply pipe is located above the first air supply pipe, and the port of the second air supply pipe extending into the side wall of the fuel supply skid-mounted unit case is a trumpet-shaped expansion, and the ratio of the inner diameter C1 of the trumpet-shaped expansion to the inner diameter C2 of the second air supply pipe is: C1 / C2=1.4:1.

[0015] The ammonia fuel supply pipeline of the utility model adopts a two-stage pressurization method, in which the first-stage pressure pump is connected in parallel with the pressure regulating valve, and the second-stage pressure pump is connected in parallel with the return pressure reduction branch, which realizes the accurate supply of the required pressure of 7.0-8.5Mps in the engine in a low-cost manner. The security system of the utility model has the ability to handle fuel leakage in both gaseous and liquid media states, especially the creative use of the flat-tongue port of the first air supply pipe and the trumpet-shaped expansion of the second air supply pipe in the fuel supply skid-mounted unit, which realizes the high-coverage high-pressure purge of the accumulated ammonia at the bottom of the fuel supply skid-mounted unit box and the high-efficiency discharge and replacement of gaseous ammonia. In addition, the security system is a closed cycle, and there is zero manual contact in the entire processing link, which significantly improves the safety and stability of marine ammonia fuel engines. The utility model provides two reflux lines, which flow back to the fuel supply pipeline and the fuel tank respectively, measure the reflux fuel pressure before diversion, and enter the relevant lines after control selection, which ensures the stability of the fuel supply pressure while reducing the consumption of cold energy. The nitrogen capture unit adopts the method of spraying ammonia to dissolve the ammonia gas in water and then sends it to the next stage for evaporation, dehydration and condensation treatment. This allows the unit to not only process the pure ammonia vapor volatilized from the liquid ammonia storage tank, but also process the ammonia-nitrogen mixed gas sent from the fuel supply skid and the collection tank, effectively increasing the working margin and processing capacity of the ammonia capture unit.

[0016] Advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments, which are given as examples only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the principle diagram of the utility model;

[0018] Figure 2 is a three-dimensional view of a flat-tongue-shaped port of a first air supply pipe;

[0019] Figure 3 It is a top view of the trumpet-shaped expansion of the second air supply pipe. DETAILED DESCRIPTION

[0020] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0021] like Figure 1As shown, the utility model includes a liquid ammonia fuel tank 1, a nitrogen tank 2, a fuel supply skid-mounted unit 3, an ammonia capture unit 4, a high-pressure common rail double-walled pipe 5, a central control unit 6 and a collection tank 7. One end of the main fuel pipe 11 extends into the liquid ammonia fuel tank 1, and the other end of the main fuel pipe 11 first passes through the straight-through ac end of the first electromagnetic three-way valve 21, and then passes through the first-stage booster pump 31 of the fuel supply skid-mounted unit 3, the electric heater 32, the straight-through ac end of the second electromagnetic three-way valve 33, the second-stage booster pump 34, the inner tube 51 of the high-pressure common rail double-walled pipe 5, and the straight-through ac end of the third electromagnetic three-way valve 35 to the marine ammonia fuel engine 10. The bypass b end of the third electromagnetic three-way valve 35 is connected to the first two-way valve 36 and the pressure reducer 37 in sequence through a branch pipe 351, and then leads to the bypass b end of the second electromagnetic three-way valve 33. Both ends of the first booster pump 31 are connected in parallel with pressure regulating valves 311.

[0022] The bypass b end of the first nitrogen solenoid three-way valve 22 is vertically connected to the right end of the outer tube 52 of the high-pressure common rail double-walled tube 5 through the nitrogen delivery pipe 221. The liquid ammonia collecting pipe 521 at the right end of the outer tube 52 of the high-pressure common rail double-walled tube 5 is connected to the collection tank 7 through the first solenoid two-way valve 53. The reflux pipe 74 at the bottom of the collection tank 7 passes through the second solenoid two-way valve 73, the reflux booster pump 38 in the fuel supply skid unit 3, and the straight ac end of the fourth solenoid three-way valve 39 in sequence, and then is connected to the straight ac end of the second solenoid three-way valve 33 and the input end of the secondary booster pump 38 in sequence through the connecting pipe 53. The liquid ammonia collecting pipe 391 connected to the bypass b end of the fourth solenoid three-way valve 39 is connected to the liquid ammonia fuel tank 1 through the cooling compressor 390. The nitrogen delivery pipe 393 at the output end of the nitrogen tank 2 is connected to the input end of the first booster pump 31 through the first nitrogen electromagnetic three-way valve 22 directly to the ac end, the second nitrogen electromagnetic three-way valve 23 directly to the ac end, and the first electromagnetic three-way valve 21 bypassing the bc end. The output pipe 3921 of the fan 392 is connected to the lower part of the fuel supply skid mounted unit box 310 through the first air supply electromagnetic three-way valve 394 directly to the ac end, the second air supply electromagnetic three-way valve 395 directly to the ac end and the first air supply pipe 396 in sequence, and the second air supply electromagnetic three-way valve 395 bypasses the b end and passes through the second air supply pipe 397 to the lower part of the fuel supply skid mounted unit box 310. The manifold 320 at the bottom of the fuel supply skid mounted unit box 310 is connected to the lower part of the collection tank 7 through the third electromagnetic two-way valve 330.

[0023] The first water pump 41 of the ammonia capture unit 4 of the security system is connected to the right end of the spray chamber 43 through the water delivery pipe 42. The bottom of the spray chamber 43 is connected to the upper end of the liquid accumulation chamber 45 through the first water delivery two-way solenoid valve 44. The water delivery three-way solenoid valve 46 at the lower end of the liquid accumulation chamber 45 is directly connected to the upper side of the input A end of the heat exchanger 47 through the hot air pipe 201 connected to the exhaust pipe 20. The delivery pipe 202 on the upper side of the output B end of the heat exchanger 47 is connected to the liquid ammonia fuel tank 1 through the liquid ammonia delivery pump 48. The connecting pipe 471 on the lower side of the input A end of the heat exchanger 47 and the connecting pipe 471 on the lower side of the output B end of the heat exchanger 47 are respectively connected to the two ends of the dehydrator 49. The dehydrator 49 is filled with alkaline desiccant to absorb the moisture in the liquid ammonia flowing through the heat exchanger 47. The air supply pipe 474 connected to the bypass b end of the water supply three-way solenoid valve 46 leads to the left side of the spray chamber 43 through the second water pump 410. The air supply pipe 474 on the right side of the spray chamber 43 is divided into two paths, which lead to the upper part of the fuel supply skid-mounted unit box 310 through the second two-way solenoid valve 473 and the two-way valve 463 respectively.

[0024] One end of a safety pipeline 420 is connected to the upper end of the liquid ammonia fuel tank 1 through a first safety valve 421, and the other end of a safety pipeline 420 is connected to the left side of the spray chamber 43; one end of another safety pipeline 420 is connected to the upper end of the collection tank 7 through a second safety valve 422, and the other end of another safety pipeline 420 is connected to the right side of the spray chamber 43.

[0025] The safety pipeline 424 between the direct ac end of the third electromagnetic three-way valve 35 and the connection end of the marine ammonia fuel engine 10 is connected to the upper part of the collection tank 7 through the third safety valve 423.

[0026] The signal line 61 of the central control unit 6 is connected to the control end of each two-way solenoid valve and the control end of each three-way solenoid valve respectively.

[0027] The liquid chamber 45 is provided with an upper liquid level gauge 451 and a lower liquid level gauge 452 in the middle and lower parts, and the collecting tank 7 is provided with an upper liquid level gauge 71 and a lower liquid level gauge 72 in the middle and lower parts. The liquid chamber 45 is also connected to an ammonia concentration gauge 453 in the liquid chamber, the upper part of the fuel supply skid-mounted unit box 310 is connected to a box ammonia concentration gauge 307, the bottom is connected to a box liquid level gauge 312, and the manifold 320 is connected to a manifold liquid level gauge 303. The two safety lines 420 are connected to a first flow meter 431 and a second flow meter 432 respectively. The first pressure sensor 321 and the first temperature sensor 322 are respectively connected to the main fuel pipe 11 at both ends of the electric heater 32, the second pressure sensor 371 is connected to the pipeline at the output end of the pressure reducer 37, the third pressure sensor 511 is connected to the main fuel pipe 11 connecting the secondary booster pump 34 and the inner tube 51 of the high-pressure common rail double-walled tube, the fourth pressure sensor 381 is connected to the pipeline connecting the reflux booster pump 38 and the fourth electromagnetic three-way valve 39 through the ac end, the first safety pipeline flow meter 431 and the second safety pipeline flow meter 432 are respectively connected to the safety pipeline 420 connected to the two sides of the spray chamber 43; the outer tube 52 of the high-pressure common rail double-walled tube 5 is connected to the outer tube level meter 522, and the liquid ammonia collecting pipe 521 is connected to the collecting pipe level meter 523.

[0028] The pressure range of the first-stage booster pump 31 outputting liquid ammonia is: 2.7~3.0Mpa, and the pressure range of the second-stage booster pump 34 outputting liquid ammonia is: 7.0~8.5Mpa. The electric heater 32 heats the liquid ammonia in the temperature range of 25~45℃, and the heating power is 50kW. The heat exchange power of the input A end of the heat exchanger 47 is 0.5kW, the cooling power of the output B end of the heat exchanger 47 is 1kW, and the temperature of the liquid ammonia output from the output B end of the heat exchanger 47 is -32~-34℃. The dehydrator 49 is filled with an alkaline desiccant.

[0029] like Figure 2 and Figure 3 As shown, the port of the first air supply pipe 396 extending into the bottom of the side wall of the fuel supply skid mounted unit case 310 is a flat tongue port, and the ratio of the inner width A1 of the flat tongue port to the inner diameter A2 of the first air supply pipe is: A1 / A2=1.4:1, and the ratio of the inner height B2 of the flat tongue port to the inner diameter A2 of the first air supply pipe is: B2 / A2=0.1:1. The second air supply pipe 397 is located above the first air supply pipe 396, and the port of the second air supply pipe 397 extending into the side wall of the fuel supply skid mounted unit case 310 is a trumpet-shaped expansion port, and the ratio of the inner diameter C1 of the trumpet-shaped expansion port to the inner diameter C2 of the second air supply pipe 397 is: C1 / C2=1.4:1. Such a structure realizes a high coverage rate and high-pressure purge of the liquid accumulated ammonia at the bottom of the fuel supply skid mounted unit case 310, so that the gaseous ammonia is efficiently discharged and replaced.

[0030] The working process of the utility model is as follows:

[0031] Before the marine ammonia fuel engine 10 is started, the control unit 6 sends a signal, the first nitrogen solenoid three-way valve 22 is directly connected to the ac end, the second nitrogen solenoid three-way valve 23 is directly connected to the ac end, the bc end of the first solenoid three-way valve 21, the abc end of the second solenoid three-way valve 33 are fully opened, the ab end of the third solenoid three-way valve 35, the ac end of the fourth solenoid three-way valve 39, and the second solenoid two-way valve 73 are opened. At this time, the nitrogen in the nitrogen tank 2 is along the nitrogen delivery pipe 393, the main fuel pipe 11, the branch pipe 351, and the reflux pipe 74 to achieve inerting and purging of the fuel supply unit, and the residual ammonia and air all enter the collection tank 7.

[0032] After 30 seconds, the control unit 6 sends a signal, the first nitrogen solenoid three-way valve 22 and the second nitrogen solenoid three-way valve 23 are closed, the valve core positions of the first solenoid three-way valve 21 through to the ac end and the other solenoid valves remain unchanged, the first-stage booster pump 31 and the second-stage booster pump 34 are turned on respectively, and the liquid ammonia in the liquid ammonia fuel tank 1 moves along the main fuel pipe 11, the branch pipe 351 and the reflux pipe 74, and the nitrogen and fuel mixture enters the collection tank 7, realizing the replacement of nitrogen by liquid ammonia in the fuel supply pipeline.

[0033] When the fourth pressure sensor 381 displays a pressure of >7.0Mpa, the fuel in the fuel supply pipeline completely replaces the nitrogen. The control unit 6 instructs the fourth electromagnetic three-way valve 39 to close, the second electromagnetic two-way valve 73 to close, and the abc ends of the third electromagnetic three-way valve 35 to fully open, and the engine 7 starts to ignite and run.

[0034] During the operation of the marine ammonia fuel engine, after the liquid ammonia fuel is pressurized by the first-stage booster pump 31, the pressure is adjusted by the pressure regulating valve 311. At this time, the first pressure sensor 321 detects a pressure range of 2.7 to 3.0 MPa; after the liquid ammonia fuel is heated by the heater 32, the first temperature sensor 322 detects a temperature range of 40 to 45°C; after the liquid ammonia fuel is pressurized again by the second-stage booster pump 31, the second pressure sensor 511 detects a pressure range of 7.0 to 8.5 MPa. At this time, the pressure and temperature of the liquid ammonia fuel are: the inlet pressure is 7.0 to 8.5 MPa, and the inlet temperature is 25 to 45°C, which meets the final inlet requirements. The liquid ammonia fuel enters the high-pressure common rail double-wall pipe 5 to supply fuel to the marine ammonia fuel engine 10. After the excess fuel is pressure-regulated by the first two-way valve 36 and reduced by the pressure reducer 37, the second pressure sensor 371 detects a pressure range of 2.7 to 3.0 MPa, and re-enters the main fuel pipeline 11 through the branch pipe 351; if the redundant fuel is large and exceeds the processing capacity of the return pipeline, the third safety valve 423 opens, and the excess fuel enters the collection tank 7. The opening threshold of the third safety valve 423 is 10 MPa.

[0035] After the marine ammonia fuel engine is shut down, the control unit 6 sends a signal, and the port on / off states of each electromagnetic three-way valve and electromagnetic two-way valve are the same as before the marine ammonia fuel engine is started. At this time, the nitrogen in the nitrogen tank 2 is purged along the nitrogen delivery pipe 393, the main fuel pipe 11, and the branch pipe 351 to purge all the residual liquid ammonia and ammonia gas into the collection tank 7. After the purge is completed, if there is a liquid level signal from the liquid level gauge 72 under the collection tank, the control unit 6 instructs to open the ab end of the fourth electromagnetic three-way valve 39, and the liquid ammonia in the collection tank 7 is directly refluxed to the liquid ammonia fuel tank 1 along the reflux pipe 74 and the liquid ammonia collecting pipe 391.

[0036] The leakage detection process of the fuel supply skid unit 3 and the high-pressure common rail double-wall pipe 5 of the security system is as follows:

[0037] When the tank liquid level meter 312 detects that there is a liquid level display or the ammonia concentration meter 307 detects that the ammonia concentration is greater than 22.8 mg / m 3 When the liquid ammonia leakage occurs in the fuel supply skid mounted unit 3, the first nitrogen electromagnetic three-way valve 22 directly connected to the ac end is opened, the ab end of the second nitrogen electromagnetic three-way valve 23 is opened, the bypass b end of the first electromagnetic three-way valve 21 is closed, the bc end of the first air supply electromagnetic three-way valve 394 is opened, and the direct ac end of the second air supply electromagnetic three-way valve 395 is opened. The nitrogen in the nitrogen tank 2 is purged along the nitrogen delivery pipe 393, the transverse pipe 231, and the first air supply pipe 396 to purge the accumulated ammonia at the bottom of the fuel supply skid mounted unit 3. The outlet pressure of the first air supply pipe 396 with a flat tongue type outlet end is 1.0Mpa, which ensures its longitudinal purge depth and the purge width of the first air supply pipe 396 in the width direction of the fuel supply skid mounted unit box 310. The third electromagnetic two-way valve 330 is opened, and the accumulated ammonia in the fuel supply skid mounted unit 3 and the liquid ammonia collecting pipe 521 enters the collection tank 7 together with the purge gas. When the manifold level gauge 303 loses the level signal, the third electromagnetic two-way valve 330 is closed, and the ammonia purge at the bottom of the fuel supply skid-mounted unit box 310 is completed. During the purge process, when the air pressure in the ammonia fuel supply skid-mounted unit 3 exceeds 0.3Mpa, the two-way valve 463 for safety is opened, and the gas enters the ammonia capture unit 4 through the two-way valve pipe port 306. The opening threshold of the two-way valve 463 is 0.3Mpa.

[0038] After the bottom purge of the fuel supply skid-mounted unit box 310 is completed, the control unit 6 sends a signal. Except that the abc ends of the first air supply electromagnetic three-way valve 394 are fully opened, the ab ends of the second air supply electromagnetic three-way valve 395 are opened, the third electromagnetic two-way valve 330 is closed, the second two-way electromagnetic valve 473 is opened, and the fan 392 is opened, the port on-off states of the remaining electromagnetic three-way valves and electromagnetic two-way valves are the same as the state during the bottom purge of the fuel supply skid-mounted unit box 310. The nitrogen and the external air blown in from the nitrogen delivery pipe 393, the cross pipe 231 and the fan 392 are blown in along the output pipe 3921 and the second air supply pipe 397 to dilute and replace the ammonia volatilized from the leaked liquid ammonia in the fuel supply skid-mounted unit 3. The end of the second air supply pipe 397 is a flared type with an air intake of 10m 3 / min, the gas with high ammonia concentration enters the ammonia capture unit 4 along the two-way solenoid valve pipe port 305 and the gas delivery pipe 474. When the ammonia concentration meter 307 shows a concentration of <1 mg / m 3 At this time, the above valves are all closed, ending the purging of the fuel supply skid-mounted unit 3.

[0039] When the outer tube liquid level gauge 522 detects a liquid level signal, the control unit 6 determines that liquid ammonia leakage occurs in the double-wall interlayer of the high-pressure common rail double-wall tube 5. At this time, the control unit 6 instructs the ab end of the first nitrogen solenoid three-way valve 22 to open, and nitrogen is purged to the double-wall interlayer of the high-pressure common rail double-wall tube 5 through the nitrogen delivery pipe 221. The first solenoid two-way valve 53 is opened, and the purged gas-liquid mixture enters the collection tank 7 through the connecting pipe 531. When the liquid accumulation tube liquid level gauge 523 on the liquid accumulation tube 521 loses the liquid level signal, the control unit 6 instructs the first nitrogen solenoid three-way valve 22 and the first solenoid two-way valve 53 to close, thereby ending the purging of the high-pressure common rail double-wall tube 5.

[0040] When the liquid level gauge 71 on the collection tank detects a liquid level signal, the second electromagnetic two-way valve 73 is opened, and ammonia flows through the reflux pipe 74 and the reflux booster pump 38. If the fourth pressure sensor 381 detects a pressure range of 2.7 to 3.0 MPa, the control unit 6 instructs the opening of the direct ac end of the fourth electromagnetic three-way valve 39, and the reflux liquid ammonia enters the main fuel pipeline 11. If the fourth pressure sensor 381 detects a pressure <2.7 MPa, the direct ac end of the fourth electromagnetic three-way valve 39 is closed, and the ab end of the fourth electromagnetic three-way valve 39 is opened. The liquid ammonia flows along the ammonia collecting pipe 391, cools down in the cooler 390 until the reflux liquid ammonia temperature is <-33.35°C, and then re-enters the liquid ammonia fuel tank 1. When the liquid level gauge 72 under the collection tank loses the liquid level signal, the control unit 6 instructs the closing of the second electromagnetic two-way valve 73, and the reflux ends. This cycle is repeated to achieve the recycling of ammonia fuel in the collection tank 7.

[0041] The storage temperature of the liquid ammonia fuel tank 1 is less than -33.35°C, and the storage pressure is greater than 0.1Mpa. Due to the volatility of liquid nitrogen, when the pressure in the liquid ammonia fuel tank 1 is greater than 0.3Mpa, the first safety valve 421 opens, and ammonia enters the ammonia capture unit 4 along the safety pipeline 420, and the opening threshold of the first safety valve 421 is 0.3Mpa; when the pressure in the collecting tank 7 is greater than 2.0Mpa, the second safety valve 422 opens, and the ammonia and nitrogen mixture enters the ammonia capture unit 4 along the safety pipeline 420, and the opening threshold of the second safety valve 422 is 2.0Mpa.

[0042] When the first safety pipeline flowmeter 431, the second safety pipeline flowmeter 432 and the gas pipeline pressure flowmeter 475 detect that there is gas flowing in the corresponding pipelines, if the liquid level gauge 451 on the liquid accumulation chamber does not detect a liquid level signal, the control unit 6 instructs to turn on the first water pump 41 to allow external water to enter the spray chamber 43. The water droplets sprayed in the spray chamber 43 are used to absorb the ammonia released from the safety pipeline 420 and the gas pipeline 474. The control unit 6 instructs the first water supply two-way solenoid valve 44 to open and the water supply three-way solenoid valve 46 to close, and the ammonia water in the spray chamber 42 is concentrated and input into the liquid accumulation chamber 45.

[0043] If the liquid level gauge 451 on the liquid accumulation chamber detects a liquid level signal and the ammonia concentration gauge 453 in the liquid accumulation chamber detects that the ammonia concentration is less than 35%, the control unit 6 instructs to close the first water pump 41, open the first water supply two-way solenoid valve 44, open the ab ends of the water supply three-way solenoid valve 46, and open the second water pump 410. At this time, the unsaturated ammonia water circulates and sprays between the spray chamber 42 and the liquid accumulation chamber 45.

[0044] If the liquid level gauge 451 on the liquid accumulation chamber detects a liquid level signal, and the ammonia concentration gauge 453 in the liquid accumulation chamber detects that the ammonia concentration is ≥35%, the control unit 6 instructs to close the second water pump 410, start the first water pump 41, and close the first water supply two-way solenoid valve 44. At this time, the unsaturated ammonia water is temporarily accumulated in the spray chamber 43, and the straight-through ac end of the water supply three-way solenoid valve 46 is opened. The saturated ammonia water enters the A end of the heat exchanger 47 for heating to form ammonia gas and water vapor, and then enters the dehydrator 49 to remove the water vapor. Then the pure ammonia gas enters the B end of the heat exchanger 47 to cool and form liquid ammonia. The control unit 6 instructs to start the liquid ammonia delivery pump 48, and the liquid ammonia re-enters the liquid ammonia fuel tank 1 through the delivery pipe 202. When the liquid level gauge 452 in the liquid accumulation chamber cannot detect a liquid level signal, the control unit 6 instructs the closing of the water supply three-way solenoid valve 46, and the opening of the first water supply two-way solenoid valve 44 and the first water pump 41, and repeats the steps of initially allowing external water to enter the spray chamber 43, thereby realizing the circulation recovery of ammonia in the ammonia capture unit 4.

[0045] In addition to the above-mentioned embodiments, the present invention may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A fuel supply and safety system for a marine ammonia fuel engine, characterized in that: It includes a liquid ammonia fuel tank, a nitrogen tank, a fuel supply skid-mounted unit, an ammonia capture unit, a high-pressure common rail double-wall pipe, a central control unit and a collection tank. One end of the main fuel pipe extends into the liquid ammonia fuel tank, and the other end of the main fuel pipe first passes through the first electromagnetic three-way valve directly to the ac end, and then passes through the first-level booster pump, the electric heater, the second electromagnetic three-way valve directly to the ac end, the second-level booster pump, the inner pipe of the high-pressure common rail double-wall pipe, and the third electromagnetic three-way valve directly to the ac end of the fuel supply skid-mounted unit to lead to the marine ammonia fuel engine. The bypass b end of the third electromagnetic three-way valve is connected to the first two-way valve and the pressure reducer in sequence through a branch pipe, and then leads to the bypass b end of the second electromagnetic three-way valve. Both ends of the first-level booster pump are connected in parallel with pressure regulating valves; The bypass b end of the first nitrogen solenoid three-way valve is vertically connected to one end of the outer tube of the high-pressure common rail double-wall tube through the nitrogen delivery pipe. The liquid ammonia collecting pipe at one end of the outer tube of the high-pressure common rail double-wall tube is connected to the collection tank through the first solenoid two-way valve. The reflux pipe at the bottom of the collection tank passes through the second solenoid two-way valve, the reflux booster pump in the fuel supply skid-mounted unit, and the fourth solenoid three-way valve directly connected to the ac end, and then connected to the direct ac end of the second solenoid three-way valve and the input end of the secondary booster pump through the connecting pipe; the liquid ammonia collecting pipe connected to the bypass b end of the fourth solenoid three-way valve is connected to the liquid ammonia fuel tank through the cooling compressor; the nitrogen tank The nitrogen delivery pipe at the output end is connected to the input end of the first-stage booster pump in sequence through the first nitrogen electromagnetic three-way valve directly connected to the ac end, the second nitrogen electromagnetic three-way valve directly connected to the ac end, and the first electromagnetic three-way valve bypass bc end; the output pipe of the fan is connected to the lower part of the fuel supply skid-mounted unit box in sequence through the first air supply electromagnetic three-way valve directly connected to the ac end, the second air supply electromagnetic three-way valve directly connected to the ac end and the first air supply pipe, and the second air supply electromagnetic three-way valve bypass b end is connected to the lower part of the fuel supply skid-mounted unit box through the second air supply pipe; the manifold at the bottom of the fuel supply skid-mounted unit box is connected to the lower part of the collection tank through the third electromagnetic two-way valve; The first water pump of the ammonia capture unit of the security system is connected to one end of the spray chamber through a water delivery pipe, the bottom of the spray chamber is connected to the upper end of the liquid accumulation chamber through the first water delivery two-way solenoid valve, the water delivery three-way solenoid valve at the lower end of the liquid accumulation chamber is directly connected to the upper side of the heat exchanger input A end through the hot air pipe connected to the exhaust pipe, and the delivery pipe on the upper side of the heat exchanger output B end is connected to the liquid ammonia fuel tank through a liquid ammonia delivery pump; the connecting pipe on the lower side of the heat exchanger input A end and the connecting pipe on the lower side of the heat exchanger output B end are respectively connected to the two ends of the dehydrator; the liquid delivery pipe connected to the bypass b end of the water delivery three-way solenoid valve is connected to one side of the spray chamber through the second water pump, and the gas delivery pipe on the other side of the spray chamber is divided into two routes, which are respectively connected to the upper part of the fuel supply skid-mounted unit box through the second two-way solenoid valve and the two-way valve; One end of a safety pipeline is connected to the upper end of the liquid ammonia fuel tank through a first safety valve, and the other end of a safety pipeline is connected to one side of the spray chamber; one end of another safety pipeline is connected to the upper end of the collection tank through a second safety valve, and the other end of another safety pipeline is connected to the other side of the spray chamber; The safety pipeline between the third electromagnetic three-way valve direct-through ac end and the marine ammonia fuel engine connection end is connected to the upper part of the collection tank through the third safety valve; The signal lines of the central control unit are respectively connected to the control ends of each two-way solenoid valve and each three-way solenoid valve.

2. The fuel supply and safety system for a marine ammonia fuel engine according to claim 1, characterized in that: The middle and lower parts of the liquid accumulation chamber are provided with an upper liquid level gauge and a lower liquid level gauge, respectively, and the middle and lower parts of the collecting tank are provided with an upper liquid level gauge and a lower liquid level gauge, respectively; the liquid accumulation chamber is also connected to an ammonia concentration gauge in the liquid accumulation chamber, the upper part of the fuel supply skid-mounted unit box is connected to an ammonia concentration gauge in the box, the bottom of the fuel supply skid-mounted unit box is connected to a box liquid level gauge, and the manifold is connected to a manifold liquid level gauge; two safety pipelines are connected to the first flow meter and the second flow meter, respectively; the main fuel pipes at both ends of the electric heater are connected to the first pressure sensor and the first temperature sensor, respectively. A second pressure sensor is connected to the pipeline at the output end of the pressure reducer, a third pressure sensor is connected to the main fuel pipe connecting the secondary booster pump and the inner tube of the high-pressure common rail double-walled tube, a fourth pressure sensor is connected to the pipeline connecting the reflux booster pump and the direct AC end of the fourth electromagnetic three-way valve, and the first safety pipeline pressure sensor and the second safety pipeline pressure sensor are connected to the safety pipelines connected to the two sides of the spray room respectively; the outer tube of the high-pressure common rail double-walled tube is connected to the outer tube level gauge, and the liquid ammonia collecting pipe is connected to the collecting pipe level gauge.

3. The fuel supply and safety system for a marine ammonia fuel engine according to claim 1, characterized in that: The pressure range of the first-stage booster pump outputting liquid ammonia is: 2.7~3.0Mpa; the pressure range of the second-stage booster pump outputting liquid ammonia is: 7.0~8.5Mpa.

4. The fuel supply and safety system for a marine ammonia fuel engine according to claim 1, characterized in that: The temperature range of the electric heater for heating liquid ammonia is 25 to 45°C, and the heating power is 50kW.

5. The fuel supply and safety system for a marine ammonia fuel engine according to claim 1, characterized in that: The heat exchange power at the input A end of the heat exchanger is 0.5kW, the cooling power at the output B end of the heat exchanger is 1kW, and the liquid ammonia temperature output at the output B end of the heat exchanger is -32 to -34°C.

6. The fuel supply and safety system for a marine ammonia fuel engine according to claim 1, characterized in that: The dehumidifier is filled with alkaline desiccant.

7. The fuel supply and safety system for a marine ammonia fuel engine according to claim 1, characterized in that: The port of the first air supply pipe extending into the bottom of the side wall of the fuel supply skid-mounted unit case is a flat-tongue type port, and the ratio of the inner width A1 of the flat-tongue type port to the inner diameter A2 of the first air supply pipe is: A1 / A2=1.4:1, and the ratio of the inner height B2 of the flat-tongue type port to the inner diameter A2 of the first air supply pipe is: B2 / A2=0.1:1; the second air supply pipe is located above the first air supply pipe, and the port of the second air supply pipe extending into the side wall of the fuel supply skid-mounted unit case is a trumpet-shaped expansion, and the ratio of the inner diameter C1 of the trumpet-shaped expansion to the inner diameter C2 of the second air supply pipe is: C1 / C2=1.4:1.

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