Marine methanol engine starting device

Abstract

The application discloses a starting device for a marine methanol engine, which comprises a compressed air control unit, a compressed air starting unit, a supplementary combustion unit, a rotating speed signal sensor and a plurality of Hall sensors. The compressed air control unit comprises a pressure reducing valve, a first one-way valve and a first electromagnetic reversing valve. The compressed air starting unit comprises a first electromagnetic on-off valve, a second electromagnetic reversing valve, a first pneumatic reversing valve, a second one-way valve, a second pneumatic reversing valve and a silencer. The supplementary combustion unit comprises a second electromagnetic on-off valve, a common rail pipe, a supplementary combustion gas injection valve, a third one-way valve and a third electromagnetic on-off valve. The starting device can quickly realize the cold state starting and the hot state starting of the marine methanol engine by using a small number of valve combinations, has high automation degree and good integration degree, and conveniently and efficiently solves the difficult starting problem of the marine methanol fuel engine.

Description

Technical Field

[0001] This invention relates to a starting device for a new energy engine, and more particularly to a starting device for a marine medium-speed (300rpm≤n≤1000rpm) direct-injection methanol engine, belonging to the field of new energy engine technology. Background Technology

[0002] Methanol fuel, as a carbon-neutral clean energy source, is attracting increasing attention. Major global marine engine manufacturers are accelerating the research and development of methanol-fueled engines, continuously improving and upgrading methanol engine technology. Currently, direct-injection methanol-fueled medium-speed engines are still in the research and development stage, and no mature and reliable products have been launched on the market. Because methanol engines mainly use direct-injection technology, the cylinder head area of ​​marine methanol engines limits their starting process. Typically, diesel micro-injection ignition and methanol main injection are used to start marine methanol engines. However, methanol has a low calorific value and high latent heat of vaporization. To ensure engine power, the injection quantity of methanol would be twice that of diesel. This makes it difficult for the engine to ignite in the cylinder during startup, resulting in starting difficulties for marine methanol engines, especially cold starts, which are often unsuccessful. Therefore, a new starting device for marine methanol engines needs to be developed to solve these problems. Summary of the Invention

[0003] The purpose of this invention is to provide a starting device for marine methanol engines, solving the problem of difficulty in starting marine methanol fuel engines when ignited by diesel micro-injection.

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

[0005] A starting device for a marine methanol engine includes a compressed air control unit, a compressed air starting unit, a combustion afterburner unit, a speed signal sensor, and several Hall effect sensors.

[0006] The compressed air control unit includes a pressure reducing valve, a first check valve, and a first solenoid directional valve; the compressed air input port A is connected to the pressure reducing valve, the first check valve, and the first solenoid directional valve in sequence through a connecting pipe, and then leads to the upper input port B of the intake valve inside the cylinder head.

[0007] The compressed air starting unit includes a first electromagnetic switch valve, a second electromagnetic reversing valve, a first pneumatic reversing valve, a second check valve, a second pneumatic reversing valve, and a muffler. The compressed air input port A is connected to the first electromagnetic switch valve, the first pneumatic reversing valve, and the second check valve in sequence through a connecting pipe, and then leads to the lower input port C of the intake valve inside the cylinder head. The compressed air input port A is also connected to the control terminal of the second pneumatic reversing valve through the second electromagnetic reversing valve. The input port of the second pneumatic reversing valve is connected to the connecting pipe from the second check valve to the lower input port C of the intake valve inside the cylinder head. The output port of the second pneumatic reversing valve is connected to the muffler.

[0008] The afterburning unit includes a second electromagnetic switch valve, a common rail pipe, an afterburning gas injection valve, a third check valve, and a third electromagnetic switch valve. The afterburning gas injection valve is located on one side of the common rail pipe and is connected to the afterburning gas input port D. The connecting pipe of the compressed air input port A is connected to one end of the common rail pipe through the second electromagnetic switch valve. The other side of the common rail pipe is connected to the third check valve and the third electromagnetic switch valve in sequence through a connecting pipe and then leads to the connecting pipe between the input ports of the second check valve and the second pneumatic reversing valve.

[0009] The speed signal sensor is supported in the frame by a speed signal sensor bracket, and the speed signal sensor is adjacent to the outer circle of the flywheel at one end of the engine crankshaft; the several Hall sensors are respectively supported in the frame by Hall sensor brackets, and are adjacent to the position gear plate.

[0010] The objectives of this invention can also be further achieved through the following technical measures.

[0011] Furthermore, the pressure sensor is fixed on the other end of the common rail pipe, and the pressure sensor is also connected to the connecting pipe outside the compressed air input port A, as well as the connecting pipe between the first check valve and the first solenoid directional valve; the signal lines of each pressure sensor and each solenoid valve are respectively connected to the PLC controller, and the PLC controller is also connected to the Hall sensor and the speed signal sensor through signal lines.

[0012] Furthermore, the initial function of the valve core of the first electromagnetic directional valve is the disconnect function, and the initial function of the valve core of the second electromagnetic directional valve is the conduction function; the initial function of the valve core of the first pneumatic directional valve is the disconnect function, and the initial function of the valve core of the second pneumatic directional valve is the conduction function.

[0013] Furthermore, the position gear is fixed on one side of the corresponding cam on the engine valve train camshaft. The position gear extends radially with a pair of upper and lower teeth spaced 180° apart. The upper teeth correspond to the exhaust top dead center position of the corresponding cylinder of the engine, and the lower teeth correspond to the compression top dead center position of the corresponding cylinder of the engine. The Hall sensor is radially adjacent to the position gear.

[0014] Furthermore, the pressure sensor has a pressure measurement range of 0–5 MPa and an output signal type of 4–20 mA.

[0015] This invention, controlled by a PLC controller, enables the input 3MPa compressed air to undergo a combination of opening and closing actions of corresponding electromagnetic switching valves, electromagnetic reversing valves, pneumatic reversing valves, and supplementary combustion gas injection valves in the compressed air control unit, compressed air starting unit, and afterburner unit. After the supplementary combustion gas enters the common rail of the afterburner unit and mixes with the high-pressure air, it passes through the corresponding valve in the afterburner unit and enters the cylinder head intake port. Through commands from the PLC controller, the supplementary combustion gas enters the cylinder through the intake valve, rapidly igniting diesel fuel and subsequently methanol fuel, thus successfully starting the engine. This invention achieves rapid cold and hot engine starts for marine methanol engines with a small number of valve combinations, exhibiting a high degree of automation and integration, conveniently and efficiently solving the problem of difficult starting of marine methanol fuel engines.

[0016] 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

[0017] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments thereof.

[0019] like Figure 1 As shown, the present invention includes a compressed air control unit 1, a compressed air start-up unit 2, a combustion supplement unit 3, a speed signal sensor 4, and several Hall sensors 5.

[0020] The compressed air control unit 1 uses 0.8 MPa compressed air to first open the intake valve 20 through the lower input port C, allowing 3 MPa compressed air to enter the upper input port B of the intake valve 20 through the compressed air starting unit 2 to open the intake valve 20. It includes a pressure reducing valve 11, a first check valve 12, and a first solenoid directional valve 13. The compressed air input port A is connected to the pressure reducing valve 11, the first check valve 12, and the first solenoid directional valve 13 sequentially via a connecting pipe 10, and then leads to the upper input port B of the intake valve 20 inside the cylinder head 20.

[0021] The compressed air starting unit 2 is used to open the intake valve 20, allowing supplementary combustion gas to quickly enter the cylinder. It includes a first solenoid valve 21, a second solenoid directional valve 22, a first pneumatic directional valve 23, a second check valve 24, a second pneumatic directional valve 25, and a muffler 26. The compressed air input port A is connected sequentially to the first solenoid valve 21, the first pneumatic directional valve 23, and the second check valve 24 via a connecting pipe 10, and then leads to the lower input port C of the intake valve 20 inside the cylinder head 30. The compressed air input port A is also connected to the control terminal 251 of the second pneumatic directional valve via the second solenoid valve 22. The input terminal 252 of the second pneumatic directional valve is connected in parallel to the connecting pipe 10 from the second check valve 24 to the lower input port C of the intake valve 20 inside the cylinder head 30. The output terminal of the second pneumatic directional valve 25 is connected to the muffler 26. Once the engine has started and the compressed air at port A has been cut off, the remaining compressed air in the pipeline is discharged through the second pneumatic reversing valve 25 and the muffler 26, which can reduce the whistling sound of the residual gas.

[0022] The afterburning unit 3 rapidly introduces afterburning gas into the cylinder, achieving rapid ignition under the compression of the piston within the cylinder. It includes a second solenoid valve 31, a common rail pipe 32, an afterburning gas injection valve 33, a third check valve 34, and a third solenoid valve 35. The afterburning gas injection valve 33 is located on one side of the common rail pipe 32 and connected to the afterburning gas input port D. The connecting pipe 10 of the compressed air input port A is connected to one end of the common rail pipe 32 via the second solenoid valve 31. The other end of the common rail pipe 32 is connected sequentially to the third check valve 34 and the third solenoid valve 35 via the connecting pipe 10, and then leads to the connecting pipe 10 between the second check valve 24 and the input port 252 of the second pneumatic directional valve.

[0023] The speed signal sensor 4 is fixed to the frame by the speed signal sensor bracket 41. The speed signal sensor 4 is adjacent to the outer circle of the flywheel 40 at one end of the engine crankshaft and is used to detect the speed of the engine crankshaft. After the speed signal sensed by the speed signal sensor 4 is transmitted to the PLC controller 7, the PLC controller 7 instructs the relevant solenoid valves of the compressed air starting unit 2 to conduct for a certain period of time according to the set program instructions.

[0024] Several Hall sensors 5 are fixed to the frame via Hall sensor brackets 51 and are adjacent to the position gear 6. The number of Hall sensors 5 matches the number of valve cams on the engine valve camshaft 50 and is the same as the number of cylinders in the engine.

[0025] Positioning gears 6 are fixed on one side of the corresponding cams of the engine valve train camshaft 50. A pair of upper teeth 61 and lower teeth 62, spaced 180° apart, extend radially from the positioning gears 6. The upper teeth 61 correspond to the exhaust top dead center position of the corresponding cylinder, and the lower teeth 62 correspond to the compression top dead center position of the corresponding cylinder. Hall effect sensors 5 detect the position of the teeth 61. When a tooth passes the Hall effect sensor 5, a square wave signal is generated, transmitting the exhaust top dead center position and the compression top dead center position of the corresponding cylinder to the PLC controller 7.

[0026] Pressure sensor 8 is fixed to the other end of the common rail pipe. Pressure sensor 8 is also connected in parallel to the connecting pipe 10 outside the compressed air inlet A, and to the connecting pipe 10 between the first check valve 12 and the first solenoid directional valve 13. The signal lines of each pressure sensor 8 and each solenoid valve are connected to the PLC controller 7. The PLC controller 7 is also connected to the Hall sensor 5 and the speed signal sensor 4 via signal lines 71. The pressure measurement range of pressure sensor 8 is 0–5 MPa, and the output signal type is 4–20 mA.

[0027] The initial function of the valve core of the first solenoid directional valve 13 is to disconnect; the initial function of the valve core of the second solenoid directional valve 22 is to open; the initial function of the valve core of the first pneumatic directional valve 23 is to disconnect; and the initial function of the valve core of the second pneumatic directional valve 25 is to open.

[0028] The working process of this invention is as follows:

[0029] A) Start-up from cold state

[0030] The PLC controller 7 instructs the second solenoid valve 31 and the third solenoid valve 35 to be energized and opened. 3 MPa compressed air enters the afterburner unit 3 from the compressed air input port A, and enters the common rail 32 through the second solenoid valve 31. The afterburner gas enters the common rail 32 through the afterburner gas injection valve 33. After the 3 MPa compressed air and the afterburner gas are mixed, they pass through the third one-way valve 34, the third solenoid valve 35 and the lower input port C of the intake valve 20 in the cylinder head 20 in sequence, and enter the intake valve 20. According to the position signal, the PLC controller 7 causes the afterburner gas to quickly enter the cylinder, push the piston to move, increase the engine speed, and at the same time, under the compression action of the piston in the cylinder, quickly ignite the diesel fuel, and then ignite the methanol fuel, so that the engine can be successfully ignited.

[0031] B) Start-up under warm-up conditions

[0032] 3 MPa compressed air enters the compressed air starting unit 2 from the compressed air input port A, and passes sequentially through the second solenoid directional valve 22 and the control terminal 251 of the second pneumatic directional valve, causing the valve core of the second pneumatic directional valve 25 to move to the open state and the valve core of the first pneumatic directional valve 23 to move to the open state. At this time, if the PLC controller 7 sends a signal to open the first solenoid switch valve 21, the 3 MPa compressed air input from the compressed air input port A passes sequentially through the first solenoid switch valve 21, the first pneumatic directional valve 23, the second check valve 24, and the lower input port C of the intake valve 20, entering the intake valve 20. This pushes the intake valve core 201 downward, allowing the compressed air to quickly enter the cylinder, pushing the piston to move and increasing the engine speed. At the same time, under the compression action of the piston in the cylinder, the diesel fuel is quickly ignited, and then the methanol fuel is ignited, thus successfully starting the engine.

[0033] C) Control method for allowing compressed air from port C to enter the cylinder through the intake valve.

[0034] 3 MPa compressed air enters the compressed air control unit 1 through compressed air input port A, is reduced to 0.8 MPa by pressure reducing valve 11, and then passes through the first one-way valve 12. At this time, the PLC controller 7, based on the position signal, issues a command to move the valve core of the first solenoid directional valve 13 to the conducting state. The 0.8 MPa compressed air enters the intake valve 20 through the upper input port B, pushing the intake valve core 201 downward to open the intake valve 20. If high-pressure air is input at the lower input port C of the intake valve, it directly enters the cylinder through the intake valve 20, pushing the piston downward and driving the crankshaft to rotate. The PLC controller 7 controls the conduction time of the first solenoid directional valve 13 according to the speed signal and the set conduction time, so that the engine speed continuously rises to the ignition speed, thus realizing the normal start of the engine. After the engine starts successfully, the PLC controller 7 instructs the first solenoid directional valve 13 to be energized and switch the valve core to the open position, cutting off the 0.8 MPa control air. At the same time, the PLC controller 7 instructs the first solenoid switch valve 21 to open, thereby cutting off the input of 3 MPa compressed air. After the 3 MPa compressed air at port A is cut off, the first pneumatic directional valve 23 loses pressure and resets, thus disconnecting the air path. The second pneumatic directional valve 25 loses pressure and resets, thus opening the air path. The remaining high-pressure air in the pipeline is discharged in sequence through the second pneumatic directional valve 25 and the silencer 26.

[0035] 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 starting device for a marine methanol engine, characterized in that, It includes a compressed air control unit, a compressed air start-up unit, a combustion afterburner unit, a speed signal sensor, and several Hall effect sensors; The compressed air control unit includes a pressure reducing valve, a first check valve, and a first solenoid directional valve. The compressed air input port A is connected to the pressure reducing valve, the first check valve, and the first solenoid directional valve in sequence through a connecting pipe, and then leads to the upper input port B of the intake valve inside the cylinder head. The compressed air starting unit includes a first electromagnetic switch valve, a second electromagnetic reversing valve, a first pneumatic reversing valve, a second check valve, a second pneumatic reversing valve, and a muffler. The compressed air input port A is connected to the first electromagnetic switch valve, the first pneumatic reversing valve, and the second check valve in sequence through a connecting pipe, and then leads to the lower input port C of the intake valve inside the cylinder head. The compressed air input port A is also connected to the control terminal of the second pneumatic reversing valve through the second electromagnetic reversing valve. The input port of the second pneumatic reversing valve is connected to the connecting pipe from the second check valve to the lower input port C of the intake valve inside the cylinder head. The output port of the second pneumatic reversing valve is connected to the muffler. The afterburning unit includes a second electromagnetic switch valve, a common rail pipe, an afterburning gas injection valve, a third check valve, and a third electromagnetic switch valve. The afterburning gas injection valve is located on one side of the common rail pipe and is connected to the afterburning gas input port D. The connecting pipe of the compressed air input port A is connected to one end of the common rail pipe through the second electromagnetic switch valve. The other side of the common rail pipe is connected to the third check valve and the third electromagnetic switch valve in sequence through a connecting pipe and then leads to the connecting pipe between the input ports of the second check valve and the second pneumatic reversing valve. The speed signal sensor is supported in the frame by a speed signal sensor bracket, and the speed signal sensor is adjacent to the outer circle of the flywheel at one end of the engine crankshaft; the several Hall sensors are supported in the frame by Hall sensor brackets and are adjacent to the position gear plate. The pressure sensor is fixed on the other end of the common rail pipe. The pressure sensor is also connected to the connecting pipe outside the compressed air input port A, and to the connecting pipe between the first check valve and the first solenoid directional valve. The signal lines of each pressure sensor and each solenoid valve are connected to the PLC controller. The PLC controller is also connected to the Hall sensor and the speed signal sensor through signal lines. The position gear is fixed on one side of the corresponding cam on the engine valve train camshaft. The position gear extends radially with a pair of upper and lower teeth spaced 180° apart. The upper teeth correspond to the exhaust top dead center position of the corresponding cylinder of the engine, and the lower teeth correspond to the compression top dead center position of the corresponding cylinder of the engine. The Hall sensor is radially adjacent to the position gear.

2. The marine methanol engine starting device as described in claim 1, characterized in that, The initial function of the valve core of the first electromagnetic directional valve is to disconnect, and the initial function of the valve core of the second electromagnetic directional valve is to open; the initial function of the valve core of the first pneumatic directional valve is to disconnect, and the initial function of the valve core of the second pneumatic directional valve is to open.

3. The marine methanol engine starting device as described in claim 1, characterized in that, The pressure sensor has a pressure measurement range of 0–5 MPa and an output signal type of 4–20 mA.

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