Fuel supply system for a marine methanol engine test bed

Abstract

The application discloses a fuel supply system for a marine methanol engine test bench, which comprises a methanol tank, a fuel pressurizing device, a pressure regulating device, a water injection unit, a temperature regulating heat exchanger, a gas permeation device, a purging device and a PLC controller, the output end of the methanol tank is sequentially connected with the fuel pressurizing device, the pressure regulating device, the water injection unit and the temperature regulating heat exchanger, and the backflow ends of two test benches are respectively connected with the backflow end of the methanol tank. The backflow port A of the pressure regulating device is connected with the backflow end of the methanol tank, the double-wall pipes connected with the water injection unit and the temperature regulating heat exchanger are respectively connected with the gas permeation device and the purging device in parallel, and the output ends of the temperature regulating heat exchanger are respectively connected with the two test benches. The application has the advantages of compact structure, convenient operation, high automation degree, good integration degree, good universality, and the ability to simultaneously meet the fuel supply requirements of marine methanol medium-speed engines and marine methanol low-speed engines, and the test efficiency of the marine methanol engine is significantly improved.

Description

Technical Field

[0001] This invention relates to a test apparatus for a new energy engine, and particularly to a fuel supply system for a bench test apparatus for a medium-speed methanol engine (300rpm≤n≤1000rpm) and a low-speed methanol engine (n≤300rpm), belonging to the field of new energy engine technology. Background Technology

[0002] With the gradual implementation of the national "dual-carbon strategy," methanol fuel, as a carbon-neutral clean energy source, has received increasing attention and has been widely applied in the field of marine propulsion. Major marine engine manufacturers worldwide are developing methanol-fueled engines, striving to bring them to market by 2025. Currently, there is no mature and reliable methanol fuel supply system to meet the testing and evaluation needs of marine methanol engines. Therefore, there is an urgent need to provide a fuel supply system for marine methanol engine test benches to solve the testing problems of methanol engines, thereby meeting the commissioning and testing needs of low-speed and medium-speed methanol engines and promoting the low-carbon development of marine engines. Summary of the Invention

[0003] The purpose of this invention is to provide a fuel supply system for a marine methanol engine test bench that can meet the requirements of low-speed methanol engine testing while also accommodating the testing and research of medium-speed methanol engines.

[0004] This invention is achieved through the following technical solution:

[0005] A fuel supply system for a marine methanol engine test bench includes a methanol tank located outside the test chamber, a fuel pressurization device, and a pressure regulating device. Inside the test chamber, a water injection unit, a temperature-regulating heat exchanger, a venting device, a purging device, and a PLC controller are also included. The methanol tank output is connected to the fuel pressurization device and the pressure regulating device sequentially via a single-walled pipe. The pressure regulating device output is connected to the water injection unit and the temperature-regulating heat exchanger sequentially via a double-walled pipe passing through a wall. The return flow ends for the low-speed and medium-speed marine methanol engine test benches are respectively connected via corresponding... The one-way valve is connected to the reflux end of the methanol tank; the reflux port A of the pressure regulating device is connected to the reflux end of the methanol tank through a single-walled pipe; the double-walled pipe connecting the water injection unit and the temperature regulating heat exchanger is connected to the venting device and the purging device respectively; the single-walled pipe at the output end of the temperature regulating heat exchanger is connected to the input end of the marine low-speed methanol engine test bench and the input end of the marine medium-speed methanol engine test bench respectively through corresponding ball valves; the signal line of the PLC controller is electrically connected to the methanol detector of the low-speed marine methanol engine test bench and the methanol detector of the medium-speed marine methanol engine respectively; the signal line is also electrically connected to the temperature sensor, water injection unit, venting device and purging device of the temperature regulating heat exchanger respectively.

[0006] The objectives of this invention can also be further achieved through the following technical measures.

[0007] Furthermore, the methanol tank is an atmospheric pressure vessel, and its capacity is more than twice that of the fuel tank of a diesel engine of the same power. The tank body is made of 316L stainless steel.

[0008] Furthermore, the fuel pressurization device includes a delivery pump, a pressurization pump, a heating heat exchanger, and a filter. The methanol tank output is connected to the delivery pump, the pressurization pump, the heating heat exchanger, and the filter in sequence via a single-walled pipe. The methanol in the methanol tank is delivered to the pressurization pump and pressurized to 1.4 MPa to 1.6 MPa by the delivery pump, then heated to 40°C to 50°C by the heating heat exchanger, and finally filtered to a maximum particle size of ≤10 μm by the filter before being input to the pressure regulating device input end through the single-walled pipe.

[0009] Furthermore, the pressure regulating device includes a first one-way valve, a first ball valve, and a first two-way solenoid valve connected in sequence through a single-walled pipe. A second two-way solenoid valve is connected in parallel on the single-walled pipe connecting the first one-way valve and the first ball valve. The second one-way valve is then connected to the return port A. The first two-way solenoid valve is connected to the inner pipe of the double-walled pipe. The outer pipe of the double-walled pipe is connected to the vent port B through a third one-way valve. One end of the overflow valve is connected in parallel at the connection between the first two-way solenoid valve and the inner pipe of the double-walled pipe. The other end of the overflow valve is connected to the return port A through the single-walled pipe.

[0010] Furthermore, the water injection unit includes a flow meter and a spray gun. One end of the double-walled pipe, connected to the output of the pressure regulating device, passes through the wall of the marine methanol engine test chamber. One end of the water injection pipe is connected to one end of the inner tube of the double-walled pipe via a second ball valve, a flow meter, and a spray gun. The other end of the double-walled pipe is connected to a temperature-regulating heat exchanger. The water pressure of the water injection unit is 0.09–0.1 MPa higher than the methanol pressure in the inner tube of the double-walled pipe, and the methanol concentration decreases by 4%–5% after water injection. The signal line of the PLC controller is electrically connected to the flow meter.

[0011] Furthermore, the temperature-regulating heat exchanger raises the methanol temperature to 68°C to 75°C by inputting hot water at 85°C to 90°C.

[0012] Furthermore, the ventilation device includes a ventilation fan and a frequency converter. The ventilation fan's output duct is connected to the outer pipe of the double-walled tube that connects the water injection unit and the temperature-regulating heat exchanger. The output air pressure of the ventilation fan is 0.09 MPa to 0.1 MPa. The frequency converter is connected to the signal line of the PLC controller.

[0013] Furthermore, the purging device includes a nitrogen cylinder, a sixth ball valve, a third two-way solenoid valve, and a purging fan connected in sequence through a single-walled pipe. The output air pipe of the purging fan is connected to the inner pipe of the double-walled pipe, and the nitrogen output pressure of the purging fan is 0.30 MPa to 0.45 MPa. The signal line of the PLC controller is electrically connected to the third two-way solenoid valve.

[0014] This invention integrates methanol fuel pressurization, pressure regulation, water injection, temperature regulation, ventilation, purging, control, and safety into one system, providing a highly efficient and high-quality methanol fuel supply system for marine methanol engine bench testing. It features a compact structure, convenient operation, high degree of automation, and good integration. It can simultaneously meet the fuel supply requirements of both medium-speed and low-speed marine methanol engines, has good versatility, and significantly improves the bench testing efficiency of marine methanol engines.

[0015] The advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments, which are given by way of example only with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments thereof.

[0018] like Figure 1 As shown, the present invention includes a methanol tank 1 located outside a marine methanol engine test chamber 10, a fuel pressurization device 2 and a pressure regulating device 3, and a water injection unit 4, a temperature regulating heat exchanger 5, a venting device 6, a purging device 7 and a PLC controller 8 located inside the marine methanol engine test chamber 10. The methanol tank output end 11 is connected to the fuel pressurization device 2 and the pressure regulating device 3 in sequence via a single-wall pipe 20. The methanol tank 1 is an atmospheric pressure vessel with a capacity more than twice that of a diesel engine fuel tank of the same power. The tank body of the methanol tank 1 is made of 316L stainless steel to prevent cavitation and extend its service life.

[0019] The fuel pressurization device 2 includes a delivery pump 21, a pressurization pump 22, a heating heat exchanger 23, and a filter 24, which are connected in sequence via a single-walled pipe 20. The delivery pump 21 and the pressurization pump 22 pressurize the methanol in the methanol tank 1 to 1.0 MPa, and then heat it to 45°C through the heating heat exchanger 23. After passing through the filter 24, the methanol is filtered until the maximum particle size in the methanol is ≤10 μm before being input to the input end of the pressure regulating device 3 through the single-walled pipe 20. The heating heat exchanger 23 ensures that the methanol is always in a liquid state, avoiding cavitation caused by the methanol vaporizing due to excessively high temperature before being injected into the cylinder of the marine methanol engine.

[0020] The pressure regulating device 3 includes a first one-way valve 31, a first ball valve 32, and a first two-way solenoid valve 33 connected in sequence through a single-walled pipe 20. A second two-way solenoid valve 34 is connected to the single-walled pipe 20 between the first one-way valve 31 and the first ball valve 32, and then connected to the return port A through the second one-way valve 35. The first two-way solenoid valve 33 is connected to the inner pipe 301 of the double-walled pipe, and the outer pipe 302 of the double-walled pipe is connected to the vent port B through a third one-way valve 36. One end of the overflow valve 37 is connected to the connection between the first two-way solenoid valve 33 and the inner pipe 301 of the double-walled pipe, and the other end of the overflow valve 37 is connected to the return port A through the single-walled pipe 20. By setting the overflow pressure of the overflow valve 37 to 1.4 MPa to 1.6 MPa, the delivery pressure of methanol is controlled and the return pressure is regulated to meet the needs of the methanol engine.

[0021] The first two-way solenoid valve 33 enables normal and emergency shut-off of the fuel supply system, while the second two-way solenoid valve 34 enables timely release of methanol back into the methanol tank 1. When a sudden malfunction occurs during the testing of the marine methanol engine, the control system alarms and, via instruction from the PLC controller 8, closes the first two-way solenoid valve 33 and opens the second two-way solenoid valve 34, thereby promptly cutting off the fuel supply to the marine methanol engine and simultaneously returning the fuel in the single-wall pipe 20 to the methanol tank 1, ensuring the safety of the marine methanol engine.

[0022] The water injection unit 4 includes a flow meter 41 and a spray gun 42. One end of the double-walled pipe 30, connected to the output of the pressure regulating device 3, passes through the wall 101 of the marine methanol engine test chamber 10. One end of the water injection pipe 44 is connected to one end of the inner pipe 301 of the double-walled pipe via a second ball valve 43, the flow meter 41, and the spray gun 42. The other end of the double-walled pipe 301 is connected to the temperature-regulating heat exchanger 5. The water injection pressure of the water injection unit 4 is 0.1 MPa higher than the methanol pressure in the inner pipe 301 of the double-walled pipe, and the methanol concentration decreases by 5% after water injection. This prevents excessive latent heat of methanol vaporization, which could lead to excessively low inlet air temperature. The signal line 81 of the PLC controller 8 is electrically connected to the control valve of the spray gun 42 and the flow meter 41, respectively, to collect the actual flow rate of the injected water in a timely manner and to control the amount of water sprayed by the spray gun 42. The water injection unit 4 provides sufficient flow and pressure of fresh water for the methanol / water mixing design to reduce nitrogen oxide emissions and meet the IMO Tier III standard (the third level standard of the International Maritime Organization for reducing engine exhaust pollution).

[0023] The temperature-regulating heat exchanger 5 uses hot water at 85℃~90℃ for heat exchange, raising the methanol temperature to 68℃~75℃. The single-walled tube 20 at the output end of the temperature-regulating heat exchanger 5 is connected to the input ends of the marine low-speed methanol engine test bench 40 and the marine medium-speed methanol engine test bench 50 via the fourth ball valve 51 and the fifth ball valve 52, respectively. Depending on the application, the fourth ball valve 51 or the fifth ball valve 52 is opened to deliver 70℃ methanol / water mixed fuel to the marine low-speed methanol engine or the marine medium-speed methanol engine for testing. The return ends of the low-speed marine methanol engine test bench 40 and the medium-speed marine methanol engine test bench 50 are connected to the methanol tank return end 12 via the corresponding fourth one-way valve 401 and fifth one-way valve 501, respectively.

[0024] Signal line 81 of PLC controller 8 is electrically connected to methanol detector 402 of the low-speed marine methanol engine test bench and methanol detector 502 of the medium-speed marine methanol engine, respectively. Signal line 81 is also electrically connected to temperature sensor 53 of temperature-regulating heat exchanger 5. When methanol detector 402 of the low-speed marine methanol engine test bench or methanol detector 502 of the medium-speed marine methanol engine detects fuel leakage, the control system alarms and, through instruction from PLC controller 8, closes the first two-way solenoid valve 33 and opens the second two-way solenoid valve 34, promptly cutting off the fuel supply to the marine methanol engine. At the same time, the fuel in the single-wall pipe 20 is returned to the methanol tank 1 to ensure the safety of the marine methanol engine under test. When the fuel temperature detected by temperature sensor 53 of temperature-regulating heat exchanger 5 is outside the permissible range, the control system alarms and must promptly close the fourth ball valve 51 or the fifth ball valve 52 to stop the fuel supply to the low-speed marine methanol engine test bench 40 or the medium-speed marine methanol engine 50.

[0025] The ventilation device 6 includes a ventilation fan 61 and a frequency converter 62. The ventilation fan's output duct 611 is connected to the outer pipe 301 of the double-walled tube, which connects the water injection unit 4 and the temperature-regulating heat exchanger 5. The output air pressure of the ventilation fan 61 is 0.1 MPa. The frequency converter 62 is connected to the signal line 81 of the PLC controller. During the testing of the marine low-speed methanol engine or the marine medium-speed methanol engine, positive pressure air is supplied to the outer pipe 302 of the double-walled tube through the ventilation fan 61 until it is discharged into the atmosphere through the vent B.

[0026] The purging device 7 includes a nitrogen cylinder 71, a sixth ball valve 72, a third two-way solenoid valve 73, and a purging blower 74, all connected sequentially via a single-walled pipe 20. The purging blower's output duct 741 is connected to the inner pipe 301 of the double-walled pipe. The nitrogen pressure output by the purging blower 74 is 0.30 MPa to 0.45 MPa. During the testing of the marine methanol engine, in the event of a leak, or during startup and shutdown, the third two-way solenoid valve 73 is opened via a command from the PLC controller 8. Nitrogen from the nitrogen cylinder 71 is then released through the purging blower 74, and any residual methanol in the inner pipe 302 of the double-walled pipe is discharged through the return port A of the pressure regulating device 3 and the exhaust pipe 12 at the top of the methanol tank 1, ensuring the safe operation of the marine methanol engine on the test bench.

[0027] In addition to the above embodiments, the present invention may have other implementation methods. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A fuel supply system for a marine methanol engine test bench, characterized in that, This includes a methanol tank, a fuel pressurization device, and a pressure regulating device located outside the marine methanol engine test chamber; and a water injection unit, a temperature regulating heat exchanger, a venting device, a purging device, and a PLC controller located inside the marine methanol engine test chamber. The output end of the methanol tank is connected to the fuel pressurization device and the pressure regulating device sequentially via a single-wall pipe. The output end of the pressure regulating device is connected to the first double-wall pipe, which passes through a wall and is then connected to the water injection unit and the temperature regulating heat exchanger inside the marine methanol engine test chamber. The return flow ends of the low-speed and medium-speed marine methanol engine test benches are connected to the methanol tank via corresponding one-way valves. The flow end is connected; the return port A of the pressure regulating device is connected to the return end of the methanol tank through a single-walled pipe; the double-walled pipe connecting the water injection unit and the temperature regulating heat exchanger is connected to the venting device and the purging device respectively; the single-walled pipe at the output end of the temperature regulating heat exchanger is connected to the input end of the marine low-speed methanol engine test bench and the input end of the marine medium-speed methanol engine test bench respectively through the corresponding ball valves; the signal line of the PLC controller is electrically connected to the methanol detector of the low-speed marine methanol engine test bench and the methanol detector of the medium-speed marine methanol engine respectively; the signal line is also electrically connected to the temperature sensor, water injection unit, venting device and purging device of the temperature regulating heat exchanger respectively.

2. The fuel supply system for a marine methanol engine test bench as described in claim 1, characterized in that, The methanol tank is an atmospheric pressure vessel with a capacity more than twice that of a diesel engine fuel tank of the same power. The tank body is made of 316L stainless steel.

3. The fuel supply system for a marine methanol engine test bench as described in claim 1, characterized in that, The fuel pressurization device includes a delivery pump, a pressurization pump, a heating heat exchanger, and a filter. The methanol tank output is connected to the delivery pump, pressurization pump, heating heat exchanger, and filter in sequence via a single-walled pipe. The methanol in the methanol tank is delivered to the pressurization pump and pressurized to 1.4 MPa to 1.6 MPa by the delivery pump, then heated to 40°C to 50°C by the heating heat exchanger, and finally filtered to ensure that the maximum particle size in the methanol is ≤10 μm before being input to the input end of the pressure regulating device through the single-walled pipe.

4. The fuel supply system for a marine methanol engine test bench as described in claim 1, characterized in that, The pressure regulating device includes a first check valve, a first ball valve, and a first two-way solenoid valve connected in sequence through a single-walled pipe. A second two-way solenoid valve is connected to the single-walled pipe between the first check valve and the first ball valve. The second check valve is then connected to the return port A. The first two-way solenoid valve is connected to the inner pipe of a double-walled pipe. The outer pipe of the double-walled pipe is connected to the vent port B through a third check valve. One end of the overflow valve is connected to the connection between the first two-way solenoid valve and the inner pipe of the first double-walled pipe. The other end of the overflow valve is connected to the return port A through a single-walled pipe.

5. The fuel supply system for a marine methanol engine test bench as described in claim 1, characterized in that, The water injection unit includes a flow meter and a spray gun. One end of the double-walled pipe connected to the output end of the pressure regulating device passes through the wall of the marine methanol engine test chamber. One end of the water injection pipe is connected to one end of the inner pipe of the double-walled pipe in sequence through a second ball valve, a flow meter, and a spray gun. The other end of the double-walled pipe is connected to a temperature regulating heat exchanger.

6. The fuel supply system for a marine methanol engine test bench as described in claim 5, characterized in that, The water injection pressure of the water injection unit is 0.09 MPa to 0.1 MPa greater than the methanol pressure in the inner tube of the double-walled pipe. After water injection, the methanol concentration decreases by 4% to 5%. The signal line of the PLC controller is electrically connected to the flow meter.

7. The fuel supply system for a marine methanol engine test bench as described in claim 1, characterized in that, The temperature-regulating heat exchanger raises the methanol temperature to 68℃~75℃ by inputting hot water at 85℃~90℃.

8. The fuel supply system for a marine methanol engine test bench as described in claim 1, characterized in that, The ventilation device includes a ventilation fan and a frequency converter. The ventilation fan's output duct is connected to the outer pipe of the double-walled tube that connects the water injection unit and the temperature-regulating heat exchanger. The output air pressure of the ventilation fan is 0.09 MPa to 0.1 MPa. The frequency converter is connected to the signal line of the PLC controller.

9. The fuel supply system for a marine methanol engine test bench as described in claim 1, characterized in that, The purging device includes a nitrogen cylinder, a sixth ball valve, a third two-way solenoid valve, and a purging fan connected in sequence through a single-walled pipe. The output air pipe of the purging fan is connected to the inner pipe of the double-walled pipe, and the nitrogen output pressure of the purging fan is 0.30 MPa to 0.45 MPa. The signal line of the PLC controller is electrically connected to the third two-way solenoid valve.

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