KR102522655B1 - Ship Engine and Method for Ship Engine - Google Patents

Abstract

The present invention provides a marine engine and marine engine control comprising the steps of measuring the pressure of each of a plurality of cylinders, calculating the pressure deviation from the measured pressures for each cylinder, and compensating for the calculated pressure deviation for each cylinder. It's about how.

Description

Ship engine and ship engine control method {Ship Engine and Method for Ship Engine}

The present invention relates to a ship engine and a method for controlling a ship engine for efficiently propelling a ship.

In general, marine engines include various engines such as a diesel engine, a gas turbine engine, and a dual fuel engine. In particular, the dual fuel engine (Dual Fuel Engine) is two fuel. For example, it is widely used in ships due to the advantage of being able to use gas and diesel in parallel.

Ships equipped with such a dual fuel engine (hereinafter referred to as 'ships') use either a gas mode that uses gas as the main fuel to generate propulsion driving force or a diesel mode that uses diesel as the main fuel to generate propulsion driving force. to drive

The dual fuel engine consists of a cylinder, a piston reciprocating up and down in the cylinder, a cylinder cover installed on the top of the cylinder, a main injector installed on the cylinder cover to inject diesel fuel in diesel mode, and a gas installed on the cylinder cover in gas mode. A diesel injector that injects a small amount of diesel fuel to ignite the fuel, an exhaust valve installed on the cylinder cover to discharge the exhaust gas burned in the cylinder, an exhaust receiver that receives the exhaust gas discharged from the cylinder, and installed on the lower side of the cylinder. It includes a scavenge receiver for supplying air to the inside of the cylinder, and a gas supply unit installed between the upper and lower sides of the cylinder to supply gas fuel to the inside of the cylinder. In addition, the dual fuel engine includes a turbocharger that increases the output of the engine by increasing the amount of air supplied to the cylinder using exhaust gas discharged from the cylinder. Air compressed by the turbocharger can be supplied to the scavenger receiver and supplied to the cylinder.

On the other hand, in the conventional marine engine, when operating in gas mode, after supplying scavenging air from the lower side of the cylinder to the inside, the gas supply part supplies gas fuel to the cylinder between the lower and upper sides of the cylinder while the piston moves upward, and the piston It moves further upward to generate thrust by compressing and burning the scavenge air and gas fuel supplied to the cylinder. Here, the marine engine according to the prior art includes a plurality of cylinders.

Since the marine engine according to the prior art includes a plurality of cylinders, there is a problem in that pressure deviation occurs for each cylinder. Here, the pressure includes both compression pressure and explosion pressure. Occurrence of a pressure deviation between cylinders means that there is a difference in the amount of air and fuel supplied to each cylinder, so there is a problem in that there is a difference in output generated by each cylinder. In this case, there is a problem in that engine life is shortened and engine efficiency is lowered due to a difference in durability for each cylinder. Therefore, there is an urgent need to develop a marine engine and a method for controlling a marine engine capable of controlling a pressure deviation occurring between cylinders.

The present invention has been made to solve the above-mentioned problems, and is to provide a marine engine and a method for controlling a marine engine capable of reducing a pressure deviation generated between cylinders according to the load of the engine.

In order to solve the problems as described above, the present invention may include the following configuration.

A marine engine according to the present invention includes a plurality of cylinders provided in the engine; a plurality of pistons movably installed in each of the cylinders in a vertical direction; a plurality of diesel injectors supplied to each of the cylinders to inject liquid fuel to ignite the compressed air and fuel; a plurality of pressure measurement units for measuring compression pressure or explosion pressure of each of the cylinders; a plurality of exhaust valves for discharging exhaust gas from each of the cylinders; and a controller for independently controlling the diesel injectors and the exhaust valves. The control unit may adjust at least one of an injection timing or an injection period during which each of the diesel injectors injects liquid fuel into each of the cylinders according to compression pressure or explosion pressure for each cylinder measured by the pressure measurement units.

In the marine engine according to the present invention, the control unit may adjust the closing timing at which each of the exhaust valves closes each of the cylinders according to the compression pressure or explosion pressure for each cylinder measured by the pressure measuring units.

In the marine engine according to the present invention, the control unit, when the compression pressure or explosion pressure measured by the pressure measuring unit in one of the cylinders exceeds the preset reference compression pressure or preset reference explosion pressure of the cylinders, The exhaust valve may be controlled to delay the closing timing of the cylinder, and the diesel injector may be controlled to adjust at least one of a delay in an injection timing of the liquid fuel and a reduction in an injection period.

In the marine engine according to the present invention, the control unit, if the compression pressure or explosion pressure measured by the pressure measuring unit in one of the cylinders is less than the preset reference compression pressure or preset reference explosion pressure of the cylinders, the The exhaust valve may be controlled so as to extend the closing timing of the cylinder, and the diesel injector may be controlled such that at least one of an injection timing of the liquid fuel is increased or an injection period is increased.

In the marine engine according to the present invention, if the control unit is equal to the compression pressure or explosion pressure measured by the pressure measuring unit in one of the cylinders, the preset reference compression pressure or preset reference explosion pressure of the cylinders, The exhaust valve and the diesel injector may be controlled so that the closing timing of the cylinder and the injection timing or injection period of the liquid fuel are maintained.

The marine engine according to the present invention may include a scavenging air supply unit for supplying air to each of the cylinders. The scavenging air supply unit is installed in a scavenging receiver storing the air at a predetermined pressure, a plurality of scavenging air supply pipes connecting the scavenging receiver and each of the cylinders, and each of the scavenging supply pipes to supply air to each of the cylinders. It may include a plurality of scavenging pressure measuring instruments for measuring the pressure of. The control unit may respectively control the exhaust valves to adjust the closing timing of each of the cylinders according to the air pressures measured by the scavenging pressure measurement devices.

Marine engine control method according to the present invention comprises the steps of measuring the pressure of each of a plurality of cylinders; Calculating a pressure deviation from the measured pressures for each cylinder; and compensating for the calculated pressure deviation for each cylinder.

In the marine engine control method according to the present invention, the step of measuring the pressure of each of the plurality of cylinders may include measuring the compression pressure or explosion pressure for each cylinder or measuring the scavenging pressure or explosion pressure for each cylinder. there is.

In the marine engine control method according to the present invention, the step of calculating the pressure deviation comprises subtracting the measured compression pressures of each of the cylinders from a preset reference compression pressure; and subtracting the measured explosion pressures of each of the cylinders from a predetermined reference explosion pressure.

In the marine engine control method according to the present invention, calculating the pressure deviation may further include subtracting pressures of air supplied to each of the cylinders from a predetermined reference scavenging pressure.

In the marine engine control method according to the present invention, the step of compensating for the calculated pressure deviation comprises: delaying the closing timing of the cylinder if the pressure deviation of the calculated compression pressure is a positive value; pulling the closing timing of the cylinder when the pressure deviation of the calculated compression pressure is a negative value; and maintaining the closing timing of the cylinder when the pressure deviation of the calculated compression pressure is zero.

In the marine engine control method according to the present invention, the step of compensating for the calculated pressure deviation is at least one of delaying the injection timing of the liquid fuel supplied to the cylinder or reducing the injection period when the pressure deviation of the calculated explosion pressure is a positive value. adjusting any one; adjusting at least one of a pull in injection timing or an increase in injection period of the liquid fuel supplied to the cylinder when the pressure deviation of the calculated explosion pressure is a negative value; and maintaining an injection timing or injection period of the liquid fuel supplied to the cylinder when the pressure deviation of the calculated explosion pressure is zero.

In the marine engine control method according to the present invention, the step of compensating for the calculated pressure deviation comprises: delaying the closing timing of the cylinder when the calculated pressure deviation of the scavenging pressure is a positive value; pulling the closing timing of the cylinder when the calculated pressure deviation of the scavenging pressure is a negative value; and maintaining the closing timing of the cylinder when the calculated pressure deviation of the scavenging pressure is zero.

According to the present invention, the following effects can be obtained.

The present invention is implemented to reduce a pressure deviation generated between cylinders according to an engine load, thereby increasing engine life and improving engine efficiency.

1 is a schematic block diagram of a marine engine according to the present invention
2 is a schematic view of part A of FIG. 1 for explaining a diesel injector, a pressure measuring unit, an exhaust valve and a control unit in a marine engine according to the present invention based on one cylinder.
Figure 3 is a schematic block diagram for explaining the scavenging air supply unit in the marine engine according to the present invention
Figure 4 is a schematic graph for explaining the case where the compression pressure measured by the pressure measuring unit in the marine engine according to the present invention exceeds the reference compression pressure
Figure 5 is a schematic graph for explaining the case where the compression pressure measured by the pressure measuring unit in the marine engine according to the present invention is less than the reference compression pressure
Figure 6 is a schematic graph for explaining the case where the explosion pressure measured by the pressure measuring unit in the marine engine according to the present invention exceeds the reference explosion pressure
Figure 7 is a schematic graph for explaining the case where the explosion pressure measured by the pressure measuring unit in the marine engine according to the present invention is less than the reference explosion pressure
8 is a schematic flow chart of a method for controlling a ship engine according to the present invention;
Figure 9 is a schematic block diagram for explaining the pressure deviation calculation step in the marine engine control method according to the present invention
Figure 10 is a schematic block diagram for explaining the compensation step for the compression pressure in the marine engine control method according to the present invention
Figure 11 is a schematic block diagram for explaining the compensation step for the explosion pressure in the marine engine control method according to the present invention
12 is a schematic block diagram for explaining a compensation step for scavenging pressure in a method for controlling a marine engine according to the present invention.

In this specification, it should be noted that in adding reference numerals to components of each drawing, the same components have the same numbers as much as possible, even if they are displayed on different drawings.

Meanwhile, the meaning of terms described in this specification should be understood as follows.

Singular expressions should be understood to include plural expressions unless the context clearly defines otherwise, and terms such as “first” and “second” are used to distinguish one component from another, The scope of rights should not be limited by these terms.

It should be understood that terms such as "comprise" or "having" do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, "at least one of the first, second, and third items" means two of the first, second, and third items as well as each of the first, second, and third items. It means a combination of all items that can be presented from one or more.

Hereinafter, a marine engine according to the present invention will be described in detail with reference to the accompanying drawings.

1 to 12, the marine engine 1 according to the present invention adjusts the closing timing at which each of the exhaust valves closes each of the cylinders according to the compression pressure or explosion pressure for each of a plurality of cylinders, and the compression pressure Alternatively, each of the diesel injectors is implemented to adjust at least one of an injection timing or an injection period for injecting liquid fuel into each of the cylinders according to the explosion pressure, thereby reducing the pressure deviation occurring between the cylinders, thereby increasing the lifespan of the engine and engine It is to improve efficiency.

To this end, the marine engine 1 according to the present invention includes a plurality of cylinders 2, a plurality of pistons 3, a plurality of diesel injectors 4, a plurality of pressure measuring units 5, and a plurality of exhaust valves 6 ) and a control unit 7.

The cylinder 2 is provided in the engine and provides a space for burning fuel. The plurality of pistons 3 are installed in each of the cylinders to be movable in the vertical direction. The plurality of diesel injectors 4 inject liquid fuel to ignite compressed air supplied to each of the cylinders and fuel. The plurality of pressure measuring units 5 are for measuring compression pressure or explosion pressure of each of the cylinders. The plurality of exhaust valves 6 are for discharging exhaust gas from each of the cylinders. The controller 7 is for independently controlling the diesel injectors and the exhaust valves. The controller 7 is configured to inject liquid fuel into each of the cylinders 2 from the diesel injectors 4 according to the compression pressure or explosion pressure of each cylinder 2 measured by the pressure measurement units 5. At least one of an injection timing and an injection period may be adjusted. Therefore, since the marine engine 1 according to the present invention can reduce the pressure deviation occurring between the plurality of cylinders 2, it is possible to increase the lifespan of the engine and improve engine efficiency.

Hereinafter, the plurality of cylinders 2, the plurality of pistons 3, the plurality of diesel injectors 4, the plurality of pressure measuring units 5, the plurality of exhaust valves 6 and the control unit 7 ) will be described in detail with reference to the accompanying drawings.

1 to 12, the cylinder 2 is for burning fuel. The cylinder 2 may be formed inside an engine block (not shown). The cylinder 2 has a combustion chamber into which air, fuel, etc. can be supplied. The combustion chamber may be formed in a cylindrical shape with an empty interior. A cylinder liner (not shown) may be installed between the combustion chamber and the engine block. A piston 3 may be movably installed in the cylinder 2 . For example, the piston 3 may reciprocate in a vertical direction based on the Y-axis direction (shown in FIG. 2) inside the combustion chamber. The Y-axis direction may be a direction parallel to the direction of gravity, but may be in another direction. A gas supply unit 100 (shown in FIG. 2 ) for supplying gas fuel may be coupled to the cylinder 2 . Accordingly, the combustion chamber may receive gas fuel from the gas supply unit 100 . The gas supply unit 100 may supply gas fuel to the combustion chamber after scavenge air is supplied through small pores (not shown). The small air hole is a hole formed from the lower side of the cylinder 2 through the cylinder 2, and may be installed to be connected to a small air receiver filled with air at a certain pressure. Accordingly, the air filled in the scavenging receiver may be supplied to the combustion chamber when the scavenging hole is opened. The scavenging receiver may be filled with air at a predetermined pressure by a turbo charger (not shown) receiving exhaust gas discharged from the combustion chamber and compressing and supplying air. The marine engine 1 according to the present invention may include a plurality of cylinders 2. The combustion chamber may increase or decrease in volume as the piston reciprocates. For example, the cylinder 2 may decrease in volume when the piston 3 moves upward. In this case, gas fuel and air supplied to the cylinder 2 can be compressed. When the piston 3 moves from the first position (P1, shown in FIG. 2) to the second position (P2, shown in FIG. 2), the diesel injector 4 installed on the upper side of the cylinder 2 By supplying diesel to ignite the compressed gas fuel, the mixture of gas fuel and air is combusted and exploded to move the piston 3 downward. The first position P1 is a case where the piston 3 is located at the bottom dead center. The second position (P2) is a case where the piston 3 is located at the top dead center. The pressure measured by the pressure measuring unit 5 when the piston 3 is positioned at the top dead center is the compression pressure. Explosion pressure is the pressure generated as the mixed gas compressed to the compression pressure is ignited and exploded. As the compressed mixed gas explodes, a driving force for rotating a crankshaft (not shown) is generated, and exhaust gas may be generated in a combustion chamber. Therefore, the load of the engine may be proportional to the compression pressure and explosion pressure of the cylinder (2). Therefore, the marine engine 1 according to the present invention can know the load of the engine by measuring the compression pressure or explosion pressure of each of the plurality of cylinders. The combustion chamber can increase in volume when the piston 3 moves downward. When the piston 3 moves toward the bottom dead center, the air filled in the scavenge receiver may be supplied to the combustion chamber. Accordingly, the exhaust gas generated by the combustion of the fuel in the combustion chamber may be discharged to the outside of the combustion chamber as air is supplied from the scavenging receiver. In this case, the cylinder 2 may be in an open state by an exhaust valve. Exhaust gas may be naturally discharged to the outside of the combustion chamber due to high temperature. Exhaust gas may be discharged along an exhaust pipe coupled to the cylinder 2 and supplied to an exhaust receiver (not shown).

The piston 3 is for compressing the air and fuel supplied to the combustion chamber. The piston 3 is movably installed in the combustion chamber. For example, the piston 3 may reciprocate between the bottom dead center P1 and the top dead center P2 inside the combustion chamber. The piston 3 may be formed in a cylindrical shape, but may be formed in another shape as long as it can compress fuel and air while moving in the combustion chamber. The piston 3 may be moved upward by a crankshaft (not shown) that transmits a driving force. The piston 3 may be connected to the crankshaft through a rod-shaped piston rod and a connecting rod. The piston 3 may move upward as the crankshaft rotates. The crankshaft may be rotated by a turning gear. Therefore, if the rotation angle of the crankshaft is known, the position of the piston 3 inside the cylinder 2 can be known. The piston 3 can compress fuel and air when moved upward by the crankshaft. The piston 3 may move downward at top dead center P2 as fuel and air supplied to the cylinder 2 are mixed and combusted and exploded. Accordingly, the piston 3 can reciprocate between the bottom dead center P1 and the top dead center P2 inside the cylinder 2 . The bottom dead center P1 is a point at which the piston 3 is positioned at the lowest position inside the cylinder 2 based on the Y-axis direction. The top dead center P2 is a point at which the piston 3 is located at the highest position inside the cylinder 2 based on the Y-axis direction. The marine engine 1 according to the present invention may explode compressed fuel to generate driving force when the piston 3 reaches top dead center P2. A plurality of the pistons 3 may be installed in each of the plurality of cylinders 2 .

The diesel injector 4 is for igniting compressed air and fuel supplied to the cylinder 2 and compressed by the piston 3. Here, the fuel may be gas fuel. The diesel injector 4 may be installed on a cylinder cover (not shown) located on the upper side of the cylinder 2 . Here, the upper side of the cylinder 2 means the top dead center P2 side of the piston 3. The diesel injector 4 may inject a small amount of liquid fuel into the combustion chamber to ignite the compressed air and fuel when the piston 3 is located at the top dead center P2. When the liquid fuel is injected, the compressed air and fuel are ignited and exploded. Thus, a driving force capable of rotating the crankshaft can be generated. The liquid fuel may be diesel oil, but is not limited thereto and may be other fuel as long as it can generate a driving force capable of propelling the ship. A plurality of the diesel injectors 4 may be installed for each of the plurality of cylinders 2 . Accordingly, the diesel injector 4 may inject liquid fuel into each of the cylinders 2 . Depending on the injection timing when the diesel injector 4 injects the liquid fuel into the cylinder 2, the timing at which compressed air and fuel explode in the combustion chamber may vary. For example, if the liquid fuel injection timing is delayed from the normal liquid fuel injection timing, the explosion pressure may be reduced because the explosion timing is delayed. If the liquid fuel injection timing is longer than the normal liquid fuel injection timing, the explosion timing may increase, so the explosion pressure may increase. The normal liquid fuel injection timing is a timing for injecting liquid fuel to optimize engine efficiency during an initial engine test, and may be set in advance by an operator. The explosion pressure generated according to the normal liquid fuel injection timing may be a preset reference explosion pressure (EP, shown in FIG. 4). The reference explosion pressure EP may be an average value of explosion pressures generated in each cylinder 2 during an engine initial test. Depending on the injection period during which the diesel injector 4 injects liquid fuel into the cylinder 2, pressure at which compressed air and fuel explode in the combustion chamber may vary. For example, when the liquid fuel injection period is reduced compared to the normal liquid fuel injection period, the explosion pressure can be reduced. Explosion pressure can be increased by increasing the liquid fuel injection period than the normal liquid fuel injection time. The normal liquid fuel injection period is a period during which liquid fuel is injected to optimize engine efficiency during an initial engine test, and may be set in advance by an operator. The explosion pressure generated according to the normal liquid fuel injection period may be a preset reference explosion pressure (EP). The reference explosion pressure EP may be an average value of explosion pressures generated in each cylinder 2 during an engine initial test.

The diesel injectors 4 may be connected to the controller 7 through at least one of wireless communication and wired communication. Accordingly, each of the diesel injectors 4 may be controlled by the controller 7 to adjust at least one of an injection timing or an injection period for injecting liquid fuel into each of the cylinders 2 .

The pressure measuring unit 5 is for measuring compression pressure or explosion pressure generated in the cylinder 2 . The pressure measuring unit 5 may measure the compressed pressure by measuring the pressures of compressed air and fuel when the piston 3 is located at the top dead center P2 in the cylinder 2 . The pressure measuring unit 5 measures when the compressed air and fuel explode when the diesel injector 4 injects liquid fuel after the piston 3 is positioned at the top dead center P2 in the cylinder 2. By measuring the pressure of the explosion pressure can be measured. The pressure measuring unit 5 is installed on the cylinder cover to measure the compression pressure or explosion pressure. The pressure measuring unit 5 may be a pressure sensor. A plurality of the pressure measuring units 5 may be installed for each of the plurality of cylinders 2 . Accordingly, the pressure measurement units 5 may measure the compression pressure or explosion pressure of each of the cylinders 2 . The pressure measuring unit 5 may be connected to the control unit 7 through at least one of wireless communication and wired communication. Accordingly, the pressure measuring unit 5 may provide the measured compression pressure or explosion pressure information to the control unit 7 .

The exhaust valve 6 may be movably coupled to the cylinder 2 based on the Y-axis direction. The exhaust valve 6 may be coupled to the cylinder 2 so as to be located on the upper side of the cylinder 2. The exhaust valve 6 is for opening and closing the cylinder 2 so that exhaust gas generated as fuel and air are burned is discharged from the cylinder 2. For example, by moving the exhaust valve 6 downward, the cylinder 2 and the exhaust pipe can communicate with each other. Accordingly, the exhaust valve 6 can open the cylinder 2 . In this case, the exhaust gas may be naturally discharged to the outside through the exhaust pipe due to the high temperature, or may be artificially discharged to the outside through the exhaust pipe due to the pressure of the scavenging air when the scavenging air is supplied to the inside of the cylinder 2 . As the exhaust valve 6 moves upward, the cylinder 2 and the exhaust pipe can be blocked. Accordingly, the exhaust valve 6 can close the cylinder 2 . When the exhaust valve (6) closes the cylinder (2) and the piston (3) moves toward top dead center (P2), gas fuel is supplied to the cylinder (2) and the piston (3) moves further toward top dead center (P2). If it does, the supplied gas fuel and air can be compressed. The compression pressure may vary according to the closing timing at which the exhaust valve 6 closes the cylinder 2 . For example, if the closing timing of the cylinder 2 is delayed from the normal closing timing of the cylinder 2, the compression time is delayed, so the compression pressure can be reduced. If the closing timing of the cylinder 2 is longer than the normal closing timing of the cylinder 2, the compression time point becomes earlier, so the compression pressure can be increased. The normal closing timing of the cylinder 2 is a timing for closing the cylinder 2 to optimize the efficiency of the engine during an initial test of the engine, and can be set in advance by an operator. The compression pressure generated according to the closing timing of the normal cylinder 2 may be a preset reference compression pressure (CP, shown in FIG. 4). The reference compression pressure CP may be an average value of compression pressures generated in each cylinder 2 during an initial test of the engine. A plurality of the exhaust valves 6 may be installed for each of the plurality of cylinders 2 . Accordingly, each of the exhaust valves 6 can adjust the closing timing of each of the cylinders 2 . The exhaust valves 6 may be connected to the controller 7 through at least one of wired communication and wireless communication. Accordingly, the exhaust valves 6 can open and close the cylinder 2 by being moved by the control unit 7 .

The controller 7 controls the diesel injectors 4 and the exhaust valves 6, respectively. As the control unit 7 controls the diesel injectors 4, at least one of the injection timing and injection period of the liquid fuel supplied to the cylinder 2 is changed, so that the explosion pressure compared to the preset reference explosion pressure (EP) can increase or decrease. As the control unit 7 controls the exhaust valves 6, the closing timing for closing the cylinder 2 changes, so that the compression pressure relative to the preset reference compression pressure CP can be increased or decreased.

For example, when the compression pressure or explosion pressure measured by the pressure measuring unit 5 in one of the cylinders 2 exceeds the preset reference compression pressure or preset reference explosion pressure, The exhaust valve 6 may be controlled to delay the closing timing of the cylinder, and the diesel injector 4 may be controlled to adjust at least one of a delay in an injection timing of the liquid fuel and a reduction in an injection period. The injection timing or injection period of the liquid fuel may be adjusted after the closing timing of the cylinder 2 is adjusted. Referring to FIG. 4, starting from the adjustment of the closing timing of the cylinder 2 related to the compression pressure, L is a graph showing the compression pressure according to the closing timing of the normal cylinder 2. The horizontal axis is the rotation angle of the crankshaft, and the vertical axis is the pressure. Here, when the rotational angle of the crankshaft is C, the reference compression pressure CP is generated. In addition, when the rotation angle of the crankshaft is E, the reference explosion pressure (EP) is generated. L1 is a graph showing the case where the compression pressure measured by the pressure measuring unit 5 exceeds the preset reference compression pressure. In this case, the compression pressure of L1 is generated when the rotation angle of the crankshaft is C1. As in L1, when the compression pressure measured by the pressure measurement unit 5 exceeds the preset reference compression pressure, the controller 7 controls the exhaust valve 6 to delay the closing timing of the cylinder 2. can do. The control unit 7 controls the exhaust valve 6 so that the exhaust valve 6 does not close the cylinder 2 when the rotation angle of the crankshaft is C1, and the exhaust valve 6 closes the cylinder 2 when it is C. can control. Accordingly, L1 may move in the direction of the arrow shown in FIG. 4 and become equal to the preset reference compression pressure. In this case, the explosion pressure of L1 may also be moved from E1 to E to become the same as the preset reference explosion pressure.

For example, if the compression pressure or explosion pressure measured by the pressure measuring unit 5 in one of the cylinders 2 is less than a preset reference compression pressure or a preset reference explosion pressure, the control unit 7 determines the The exhaust valve 6 may be controlled to pull the closing timing of the cylinder, and the diesel injector 4 may be controlled to adjust at least one of an injection timing of the liquid fuel and an increase in the injection period. Looking at the closing timing of the cylinder 2 related to the compression pressure with reference to FIG. 5, L2 is a graph showing the case where the compression pressure measured by the pressure measuring unit 5 is less than the preset reference compression pressure. In this case, the compression pressure of L2 is generated when the rotation angle of the crankshaft is C2. As in L2, when the compression pressure measured by the pressure measuring unit 5 is less than the preset reference compression pressure, the control unit 7 can control the exhaust valve 6 so that the closing timing of the cylinder 2 is pulled. there is. The control unit 7 controls the exhaust valve 6 so that the exhaust valve 6 does not close the cylinder 2 when the rotation angle of the crankshaft is C2, and the exhaust valve 6 closes the cylinder 2 when it is C. can control. Accordingly, L2 may move in the direction of the arrow shown in FIG. 5 and become equal to the preset reference compression pressure. In this case, the explosion pressure of L2 may also be moved from E2 to E to become the same as the preset reference explosion pressure.

Although not shown, the controller 7 determines that the compression pressure or explosion pressure measured by the pressure measuring unit 5 in one of the cylinders 2 is the same as the preset reference compression pressure or preset reference explosion pressure. If so, the exhaust valve 6 is controlled so that the closing timing of the cylinder remains the same as the cylinder closing timing of the preset reference compression pressure or the preset reference explosion pressure, and the injection timing or injection period of the liquid fuel is preset. The diesel injector 4 may be controlled so that the liquid fuel injection timing or injection period of the reference explosion pressure is maintained the same.

Looking at the injection timing or injection period adjustment of the liquid fuel related to the explosion pressure with reference to FIG. 6, L is a graph showing the explosion pressure according to the closing timing of the normal cylinder (2). The horizontal axis is the rotation angle of the crankshaft, and the vertical axis is the pressure. Here, when the rotational angle of the crankshaft is C, the reference compression pressure CP is generated. In addition, when the rotation angle of the crankshaft is E, the reference explosion pressure (EP) is generated. L3 is a graph showing the case where the explosion pressure measured by the pressure measuring unit 5 exceeds the preset reference explosion pressure. The compression pressure of L3 is CP3, and the explosion pressure is EP3. In this case, the explosion pressure (EP3) of the L3 is generated when the rotation angle of the crankshaft is E. As in L3, when the explosion pressure measured by the pressure measuring unit 5 exceeds the predetermined reference explosion pressure, the control unit 7 cannot adjust the explosion pressure by adjusting the closing timing of the cylinder 2. This is because the reference explosion pressure EP and the explosion pressure EP3 of the cylinder 2 measured by the pressure measuring unit 5 are generated at the rotation angle E of the crankshaft. Therefore, in this case, the marine engine 1 according to the present invention can adjust the explosion pressure by adjusting at least one of the liquid fuel injection timing or injection period. The controller 7 may control the diesel injector 4 so that the injection timing of the liquid fuel is delayed or the injection period is reduced when the rotation angle of the crankshaft is E. Accordingly, the explosion pressure EP3 of L3 may move in the direction of the arrow shown in FIG. 6 and become the same as the preset reference explosion pressure EP. In this case, the compression pressure of the L3 may also move from CP3 to CP to become the same as the preset reference compression pressure.

Looking at the injection timing or injection period adjustment of the liquid fuel related to the explosion pressure with reference to FIG. 7, L4 is a graph showing the case where the explosion pressure measured by the pressure measuring unit 5 is less than the predetermined reference explosion pressure. The compression pressure of L4 is CP4, and the explosion pressure is EP4. The control unit 7 may control the diesel injector 4 to adjust at least one of a pull in the injection timing of the liquid fuel and an increase in the injection period when the rotational angle of the crankshaft is E. Accordingly, the explosion pressure EP4 of L4 may move in the direction of the arrow shown in FIG. 7 and become the same as the preset reference explosion pressure EP. In this case, the compression pressure of L4 may also be moved from CP4 to CP to become the same as the preset reference compression pressure.

Accordingly, the marine engine 1 according to the present invention controls the exhaust valve 6 to adjust the closing timing of the cylinder 2, so that the compression pressure or explosion pressure of the cylinder 2 is set at a predetermined reference compression pressure ( CP) or the preset reference explosion pressure (EP). Therefore, since the marine engine 1 according to the present invention can reduce the pressure deviation occurring between a plurality of cylinders, it is possible to increase the lifespan of the engine and improve engine efficiency.

The marine engine 1 according to the present invention may include a scavenging air supply unit 8.

The scavenging air supply unit 8 supplies air to each of the cylinders 2 . The scavenging air supply unit 8 may include a scavenging air receiver 81 , a plurality of scavenging air supply pipes 82 , and a plurality of scavenging air pressure measurement devices 83 .

The scavenge receiver 81 is for supplying air to the cylinder 2 . The scavenge receiver 81 may receive and store compressed air from the turbocharger. Accordingly, the scavenging receiver 81 can store air at a predetermined pressure. For example, the scavenge receiver may store air at a pressure of 1 bar to 8 bar. The scavenging receiver 81 may be a storage tank in the form of a rectangular parallelepiped with an empty inside, but is not limited thereto and may be a storage tank of another type as long as it can store air. The scavenging receiver 81 may be connected to a scavenging hole (not shown) installed on the lower side of the cylinder 2 through the scavenging air supply pipe 82 . Since the scavenge receiver 81 receives air from the turbo charger, when the amount of air compressed by the turbo charger is small, the air is stored at a low pressure. Conversely, when the amount of air compressed by the turbocharger is large, the scavenge receiver 81 stores the air at a high pressure. The turbocharger compresses air using exhaust gas. Accordingly, the scavenging receiver 81 controls the pressure of the exhaust gas. That is, the pressure of the stored air may vary according to the load of the engine. Therefore, the pressure of the air stored in the scavenge receiver 81 is closely related to the load of the engine. For example, when the engine load is low, the air pressure supplied to the cylinder 2 is low. On the other hand, when the load of the engine is high, the air pressure supplied to the cylinder 2 is high. Therefore, the marine engine 1 according to the present invention can know the load of the engine by measuring the pressure of the air stored in the scavenge receiver 81.

The scavenging air supply pipe 82 is for moving the air stored in the scavenging receiver 81 to the cylinder 2 . The scavenging air supply pipe 82 may be a hose or a pipe. The scavenging air supply pipe 82 may have one side coupled to the scavenging receiver 81 and the other side coupled to the cylinder 2 . When the number of cylinders 2 is plural, a plurality of scavenging air supply pipes 82 may be installed to supply air to each of the plurality of cylinders 2 . The scavenging air pressure measurement device 83 may be installed in each of the scavenging air supply pipes 82 .

The vacuum pressure measuring device 83 is for measuring the air pressure supplied to the cylinder 2 . A plurality of the scavenging pressure measurement devices 83 may be installed in each of the scavenging air supply pipes 82 to measure the air pressure supplied to each of the cylinders 2 . The vacuum pressure measurement device 83 may be a pressure sensor. The vacuum pressure measurement devices 83 may be connected to the controller 7 through at least one of wireless communication and wired communication. Accordingly, the scavenging air pressure measurement devices 83 may provide information on the measured air pressure to the control unit 7 . The pressure of the air supplied to the cylinder (2) is proportional to the compression pressure of the cylinder (2). For example, if the pressure of the air supplied to the cylinder 2 is high, since a large amount of air is supplied to the cylinder 2, the compression pressure may increase. For example, when the pressure of the air supplied to the cylinder 2 is low, since a small amount of air is supplied to the cylinder 2, the compression pressure may be reduced. Therefore, the marine engine 1 according to the present invention uses the air pressure measured by the scavenging pressure measuring device 83 instead of the compressed pressure measured by the pressure measuring unit 5 to replace the cylinder of the exhaust valve 6. (2) Closing timing can be adjusted. In the marine engine 1 according to the present invention, when the air pressure measured by the scavenging pressure measuring device 83 exceeds the preset reference scavenging pressure, the exhaust valve 6 delays the closing timing of the cylinder 2. and controls the exhaust valve 6 so that the closing timing of the cylinder 2 is pulled when the air pressure measured by the scavenging pressure measuring device 83 is less than a preset reference scavenging pressure, and the scavenging pressure When the air pressure measured by the measuring instrument 83 is the same as the preset reference scavenging pressure, the exhaust valve 6 may be controlled so that the closing timing of the cylinder 2 is maintained. The specific control method of the exhaust valve 6 according to the air pressure is the same as the control method of the exhaust valve 6 according to the above-mentioned compression pressure.

Hereinafter, a method for controlling a ship engine according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 8 is a schematic flow chart of a method for controlling a marine engine according to the present invention, Figure 9 is a schematic block diagram for explaining the pressure deviation calculation step in the method for controlling a marine engine according to the present invention, Figure 10 is a marine engine according to the present invention A schematic block diagram for explaining the compensation step for the compression pressure in the control method, Figure 11 is a schematic block diagram for explaining the compensation step for the explosion pressure in the marine engine control method according to the present invention, Figure 12 is the present invention It is a schematic block diagram for explaining the compensation step for the scavenging pressure in the marine engine control method according to.

1 to 12, the marine engine control method according to the present invention may be performed by the above-described marine engine 1 according to the present invention. The marine engine control method according to the present invention includes the following configuration.

First, the pressure of each of the plurality of cylinders 2 is measured (S100). This step (S100) may be performed by the pressure measuring unit 5 measuring the compression pressure or explosion pressure of the fuel and air supplied to the cylinder 2. The pressure measuring unit 5 may measure the compression pressure or explosion pressure of each of the plurality of cylinders 2 . This step (S100) may be performed by measuring the air pressure of each of the scavenging air supply pipes 82 by the scavenging air pressure measurement devices 83. The pressure measurement units 5 may provide the measured compression pressure information or explosion pressure information to the control unit 7 through at least one of wireless communication and wired communication. The scavenging pressure measurement devices 83 may provide the measured air pressure information to the control unit 7 through at least one of wireless communication and wired communication.

Next, a pressure deviation is calculated from the measured pressures for each cylinder (S200). This step (S200) may include the following configuration.

First, the controller 7 subtracts the compression pressure measured in each cylinder 2 from the average compression pressure (S210). The average compression pressure is an average pressure of the compression pressures of each of the cylinders 2, and may be a preset reference compression pressure. Accordingly, it is possible to know the compression pressure deviation for each cylinder. For example, when the compression pressure measured by the pressure measurement unit 5 exceeds a predetermined reference compression pressure, the compression pressure deviation may have a negative value. If the compression pressure measured by the pressure measurement unit 5 is less than the preset reference compression pressure, the compression pressure deviation may have a positive value. If the compression pressure measured by the pressure measuring unit 5 is the same as the preset reference compression pressure, the compression pressure deviation may be zero.

Next, the controller 7 subtracts the explosion pressure measured in each cylinder 2 from the average explosion pressure (S220). The average explosion pressure is an average of the explosion pressures of each of the cylinders 2, and may be a predetermined reference explosion pressure. Accordingly, it is possible to know the explosion pressure deviation for each cylinder. For example, when the explosion pressure measured by the pressure measurement unit 5 exceeds a predetermined reference explosion pressure, the explosion pressure deviation may have a negative value. If the explosion pressure measured by the pressure measuring unit 5 is less than the predetermined reference explosion pressure, the explosion pressure deviation may have a positive value. If the explosion pressure measured by the pressure measuring unit 5 is the same as the preset reference explosion pressure, the explosion pressure deviation may be zero.

Next, when the marine engine 1 according to the present invention uses the air pressure measured by the scavenging pressure measuring device 83 as the compressed pressure, the control unit 7 operates each scavenging supply pipe 82 at the average scavenging pressure. Each air pressure measured in is subtracted (S230). The average scavenging pressure is an average pressure of air pressures supplied to each of the cylinders 2 , and may be a preset reference scavenging pressure. Accordingly, it is possible to know the compression pressure deviation for each cylinder. For example, when the air pressure measured by the scavenging pressure measurement device 83 exceeds the preset reference scavenging pressure, the scavenging pressure deviation may have a negative value. If the air pressure measured by the scavenging pressure measuring device 83 is less than the preset reference scavenging pressure, the scavenging pressure deviation may have a positive value. If the scavenging pressure measured by the scavenging pressure measuring device 83 is the same as the preset reference scavenging pressure, the scavenging pressure deviation may be zero.

Next, the pressure deviation calculated for each cylinder 2 is compensated (S300). This step (S300) may include the following configuration.

First, it is determined whether the calculated compression pressure deviation is a positive value (S310). This step (S310) may be performed by the control unit 7. If the deviation of the compression pressure is a positive value, the closing timing of the cylinder 2 is delayed (S311). This step (S311) may be performed by the controller 7 controlling the exhaust valve 6. Accordingly, L1 may match L as shown in FIG. 4 . If the deviation of the compression pressure is not a positive value, it is determined whether the deviation of the compression pressure is a negative value (S312). This step (S312) may be performed by the controller 7. If the deviation of the compression pressure is a negative value, the closing timing of the cylinder 2 is pulled (S312a). This step (S312a) may be performed by the controller 7 controlling the exhaust valve 6. Accordingly, L2 may match L as shown in FIG. 5 . If the deviation of the compression pressure is not a negative value, the closing timing of the cylinder 2 is maintained (S312b). This step (S312b) may be performed by the control unit 7 controlling the exhaust valve 6 according to a preset standard compression pressure.

Next, it is determined whether the calculated explosion pressure deviation is a positive value (S320). This step (S320) may be performed by the controller 7. If the deviation of the explosion pressure is a positive value, at least one of the injection timing delay or injection period reduction of the liquid fuel supplied to the cylinder 2 is adjusted (S321). This step (S321) may be performed by the controller 7 controlling the diesel injector 4. Accordingly, L3 may match L as shown in FIG. 6 . If the deviation of the explosion pressure is not a positive value, it is determined whether the deviation of the explosion pressure is a negative value (S322). This step (S322) may be performed by the controller 7. If the deviation of the explosion pressure is a negative value, at least one of pulling the injection timing or increasing the injection period of the liquid fuel supplied to the cylinder 2 is adjusted (S322a). This step (S322a) may be performed by the controller 7 controlling the diesel injector 4. Accordingly, L4 may match L as shown in FIG. 7 . If the deviation of the explosion pressure is not a negative value, the closing timing of the cylinder 2 is maintained (S322b). This step (S322b) may be performed by the control unit 7 controlling the diesel injector 4 according to a predetermined reference explosion pressure.

Next, it is determined whether the calculated scavenging pressure deviation is a positive value (S330). This step (S330) may be performed by the controller 7. If the deviation of the scavenging pressure is a positive value, the closing timing of the cylinder 2 is delayed (S331). This step (S331) may be performed by the controller 7 controlling the exhaust valve 6. Accordingly, L1 may match L as shown in FIG. 4 . If the deviation of the compression pressure is not a positive value, it is determined whether the deviation of the compression pressure is a negative value (S332). This step (S332) may be performed by the controller 7. If the deviation of the compression pressure is a negative value, the closing timing of the cylinder 2 is pulled (S332a). This step (S332a) may be performed by the controller 7 controlling the exhaust valve 6. Accordingly, L2 may match L as shown in FIG. 5 . If the deviation of the compression pressure is not a negative value, the closing timing of the cylinder 2 is maintained (S332b). This step (S332b) may be performed by the control unit 7 controlling the exhaust valve 6 according to a preset reference compression pressure.

Therefore, the marine engine control method according to the present invention can promote the following effects.

First, the marine engine control method according to the present invention measures the compression pressure or explosion pressure generated in each cylinder 2, and then closes the closing timing of each cylinder 2 and the injection timing of liquid fuel by the pressure deviation generated for each cylinder. Alternatively, the pressure deviation may be reduced by precisely adjusting at least one of the injection periods. Therefore, the marine engine control method according to the present invention can increase the service life of the engine and improve the efficiency of the engine.

Second, the marine engine control method according to the present invention adjusts the pressure deviation generated for each cylinder by adjusting at least one of the closing timing of each cylinder 2, the injection timing or injection period of liquid fuel, thereby reducing the pressure of the cylinder. Since there is no need to install a separate pressure deviation control device other than the pressure measurement unit for measurement, construction costs for pressure deviation control for each cylinder can be reduced.

Third, the marine engine control method according to the present invention can reduce the pressure deviation by detecting whether or not the pressure deviation occurs for each cylinder in real time using the pressure measuring unit 5, the scavenging pressure measuring device 83, and the control unit 7. , it is possible to further increase the service life of the engine, thereby reducing the maintenance cost and replacement cost of the engine.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention belongs that various substitutions, modifications, and changes are possible without departing from the technical spirit of the present invention. It will be clear to those who have knowledge of

1 : Marine engine
2: Cylinder 3: Piston
4: diesel injector 5: pressure measuring unit
6: exhaust valve 7: control unit
8: scavenging air supply unit 81: scavenging receiver
82: scavenging air supply pipe 83: scavenging air pressure measuring device

Claims (13)

A plurality of cylinders provided in the engine;
a plurality of pistons movably installed in each of the cylinders in a vertical direction;
a plurality of diesel injectors supplied to each of the cylinders to inject liquid fuel to ignite the compressed air and fuel;
a plurality of pressure measuring units for measuring the pressure of each of the cylinders;
a plurality of exhaust valves for discharging exhaust gas from each of the cylinders; and
A control unit for independently controlling the diesel injectors and the exhaust valves,
The control unit calculates the pressure deviation of each cylinder by subtracting the pressure of each cylinder from the average pressure obtained by averaging the pressures of each cylinder measured by the pressure measurement units, and the calculated pressure deviation is a positive value or a negative value. At least one of the closing timing of the exhaust valve, the injection timing of the diesel injector, and the injection period of the diesel injector is differently adjusted for the cylinder having
The control unit controls the exhaust valve so that the closing timing of the cylinder is adjusted when the compression pressure measured by the pressure measuring unit in one of the cylinders is out of a preset reference compression pressure of the cylinders, and Marine engine, characterized in that for controlling the diesel injector so that the injection timing or injection period of the liquid fuel is adjusted when the explosion pressure measured by the pressure measuring unit in one cylinder is out of the predetermined reference explosion pressure of the cylinders. delete delete delete According to claim 1,
When the compression pressure or explosion pressure measured by the pressure measuring unit in one of the cylinders is the same as the preset reference compression pressure or preset reference explosion pressure of the cylinders, the control unit determines the closing timing of the cylinder, the liquid fuel A marine engine characterized in that for controlling the exhaust valve and the diesel injector so that the injection timing or injection period of is maintained. According to claim 1,
A scavenging air supply unit for supplying air to each of the cylinders;
The scavenging supply unit,
a scavenging receiver for storing the air at a predetermined pressure;
a plurality of scavenging air supply pipes connecting the scavenging receiver and each of the cylinders; and
A plurality of scavenging air pressure measuring devices installed in each of the scavenging air supply pipes to measure the pressure of air supplied to each of the cylinders;
The control unit controls the exhaust valves so that the closing timing of each of the cylinders is adjusted according to the air pressures measured by the scavenging pressure measurement devices. Measuring the pressure of each of the plurality of cylinders;
Calculating a pressure deviation of each cylinder by subtracting the pressure of each cylinder from the average pressure obtained by averaging the measured pressures of each cylinder; and
Compensating for the calculated pressure deviation for each cylinder,
Compensating for the pressure difference,
Reducing the pressure deviation by differently adjusting at least one of the closing timing of the exhaust valve, the injection timing of the diesel injector, and the injection period of the diesel injector for the cylinder having the calculated pressure deviation having a positive value or a negative value, ,
Measuring the pressure of each of the plurality of cylinders,
Measuring the compression pressure or explosion pressure for each cylinder,
Compensating for the pressure difference,
When the calculated compression pressure deviates from the preset standard compression pressure, the exhaust valve is controlled to adjust the closing timing of the cylinder, and liquid fuel is injected when the calculated explosion pressure is out of the preset standard explosion pressure of the cylinders. A marine engine control method for controlling the diesel injector so that the timing or injection period is adjusted. The method of claim 7, wherein measuring the pressure of each of the plurality of cylinders
Marine engine control method comprising the step of measuring the scavenging pressure or explosion pressure for each cylinder. 9. The method of claim 8, wherein calculating the pressure difference comprises
subtracting the measured compression pressures of each of the cylinders from a preset reference compression pressure; and
A marine engine control method comprising the step of subtracting the measured explosion pressures of each of the cylinders from a predetermined reference explosion pressure. 10. The method of claim 9, wherein the step of calculating the pressure difference
The marine engine control method further comprising the step of subtracting the pressures of the air supplied to each of the cylinders from the preset reference scavenging pressure. 10. The method of claim 9, wherein the step of compensating for the calculated pressure deviation
Marine engine control method comprising the step of maintaining the closing timing of the cylinder when the pressure deviation of the calculated compression pressure is 0. 10. The method of claim 9, wherein the step of compensating for the calculated pressure deviation
Marine engine control method comprising the step of maintaining the liquid fuel injection timing or injection period supplied to the cylinder when the pressure deviation of the calculated explosion pressure is 0. 11. The method of claim 10, wherein the step of compensating for the calculated pressure deviation
delaying the closing timing of the cylinder when the calculated pressure deviation of the scavenging pressure is a positive value;
pulling the closing timing of the cylinder when the calculated pressure deviation of the scavenging pressure is a negative value; and
Marine engine control method comprising the step of maintaining the closing timing of the cylinder when the pressure deviation of the calculated scavenging pressure is 0.

Images