KR102021712B1 - EGR system and how to operate the ship - Google Patents

Abstract

In the EGR system and the ship operating method, the exhaust gas recirculation lines G5, G6 and G7, the EGR inlet valve 41 and the EGR outlet valve 45, the scrubber 42 and the EGR inlet valve 41 And a control device 80 capable of opening and closing control of the EGR outlet valve 45 and driving control of the scrubber 42, wherein the control device 80 includes an EGR inlet valve 41 at the time of input of a crash operation signal. And the EGR operation emergency stop mode in which the EGR outlet valve 45 is closed.

Description

EGR system and how to operate the ship

The present invention relates to an EGR system for reducing NOx in exhaust gas by returning a part of the exhaust gas discharged from the combustion chamber of the internal combustion engine to the combustion chamber, and a method of operating a ship equipped with the EGR system.

Reducing NOx in the exhaust gas includes exhaust gas recirculation (EGR). This EGR branches a part of the exhaust gas discharged to the exhaust line from the combustion chamber of the internal combustion engine to the exhaust gas recirculation line, mixes it into the combustion air, and returns it to the combustion chamber as the combustion gas. Therefore, the combustion gas is lowered in the oxygen concentration, and the combustion temperature is lowered by slowing down the speed of combustion, which is a reaction between the fuel and oxygen, thereby reducing the amount of NOx generated.

As a ship equipped with the internal combustion engine equipped with the exhaust gas recirculation apparatus, there exist some which were described in following patent document 1, for example.

Japanese Laid-Open Patent Publication 2011-112006

By the way, the ship which is moving forward may perform the crash astern which reverses the hull in order to avoid danger. That is, in the case of a relatively large ship, depending on the operation of the ship, the direction of rotation of the internal combustion engine is immediately reversed in order to avoid danger, and the ship is urgently stopped. In this case, when the internal combustion engine operates by operating the exhaust gas recirculation device, when the internal combustion engine is crashed and the rotation direction of the internal combustion engine is reversed, the rotation speed temporarily decreases while the oxygen in the cylinder is lean, and therefore ignition. There is a possibility that the deterioration of the properties may cause the output on the reverse side to decrease. This makes it difficult to emergency stop the vessel.

SUMMARY OF THE INVENTION The present invention solves the problems described above, and provides an EGR system and a ship operating method capable of reducing harmful substances in exhaust gas and ensuring sufficient output in a reverse direction to a traveling direction during a crash operation. It aims to do it.

An EGR system of the present invention for achieving the above object comprises an exhaust gas recirculation line for recirculating a portion of the exhaust gas discharged from the engine as combustion gas, an EGR valve formed in the exhaust gas recirculation line, And a scrubber for injecting liquid to the combustion gas flowing through the exhaust gas recirculation line, and a control device for controlling the EGR valve and the scrubber, wherein the control device includes the EGR valve at the time of input of a crash operation signal. The EGR operation emergency stop mode for abolishing the operation is possible.

Therefore, when the EGR operation emergency stop mode is executed, the EGR operation is stopped early by closing the EGR valve, so that even if a crash astonish or a crash head is applied, ignition does not occur in the cylinder. It does not deteriorate and engine power does not fall. As a result, since a sufficient output in the reverse direction to the traveling direction can be secured at the time of the crash operation, the vessel can be stopped quickly.

In the EGR system of the present invention, there is provided a purge device for supplying purge gas to the exhaust gas recirculation line, wherein the control device further controls the purge device, and at the time of input of the EGR operation stop signal, the EGR valve is provided. An EGR operation stop mode for activating the purge device with a closed box and then stopping the drive of the scrubber; and an EGR operation for stopping the operation of the purge device by closing the EGR valve upon input of the crash operation signal. The emergency stop mode can be executed.

Therefore, when the EGR operation stop mode is executed, the scrubber is operated after closing the EGR valve to operate the purge device, whereby the introduction of the combustion gas into the exhaust gas recirculation line is stopped, and the purge gas enters the exhaust gas recirculation line. Since it is supplied, the corrosion component remaining in the exhaust gas recirculation line is discharged together with the purge gas. On the other hand, when the EGR operation emergency stop mode is executed, the EGR operation can be emergency stopped early by closing the EGR valve and not operating the purge device.

In the EGR system of the present invention, the purge device includes a purge gas supply line for supplying the purge gas to the exhaust gas recirculation line, a purge valve for opening and closing the purge gas supply line, and corrosion remaining with the purge gas. And a purge gas discharge line for discharging the components.

Therefore, when the EGR shutdown mode is executed, the purge gas is supplied from the purge gas supply line to the exhaust gas recirculation line by opening the purge valve, so that the purge gas and the corrosive component are discharged from the purge gas discharge line. Supply and discharge of purge gas and corrosive components can be appropriately performed.

In the EGR system of the present invention, when the forward rotation speed of the engine is greater than or equal to the set rotation speed of the crash determination at the time of the reverse side command operation by the steering wheel, or the reverse rotation speed of the engine is determined at the time of the forward side command operation by the steering wheel. The crash operation signal is output to the control device when the rotation speed is equal to or greater than the set rotational speed or when a crash operation is arbitrarily performed in addition to the crash determination.

Thus, when the crash head and the crash astern are executed, the output in the reverse direction to the traveling direction can be sufficiently secured.

In the EGR system of the present invention, the EGR valve is an EGR inlet valve disposed upstream of the flow direction of the combustion gas from the scrubber in the exhaust gas recirculation line, and the above-mentioned in the exhaust gas recirculation line. And an EGR outlet valve disposed downstream of the flow direction of the combustion gas from the scrubber, and is downstream of the flow direction of the combustion gas from the scrubber in the exhaust gas recirculation line and from the EGR outlet valve. A blower is formed on an upstream side in the flow direction of the combustion gas, and the control device closes the EGR inlet valve and the EGR outlet valve when the EGR operation emergency stop mode is executed, and drives the blower. It is characterized by stopping.

Therefore, when the EGR operation emergency stop mode is executed, the EGR inlet valves and the EGR outlet valves are closed or operated simultaneously or sequentially, and the blower is stopped at the same time, thereby introducing exhaust gas into the exhaust gas recirculation line and recycling gas. The supply to the engine can be stopped immediately, and the output of the engine can be stabilized early.

In addition, the ship driving method of the present invention is a ship driving method comprising a propulsion engine and an EGR system for recirculating a part of the exhaust gas discharged from the engine as the combustion gas to the engine. It is characterized in that the operation of the EGR system is stopped when the stun or the crash head is executed.

Therefore, even if a crash astonish or a crash answer is applied, the air lean state in a cylinder is eliminated, and flammability does not deteriorate and engine output does not fall. As a result, it is possible to reduce the harmful substances in the exhaust gas and to sufficiently secure the output in the reverse direction to the traveling direction during the crash operation.

According to the EGR system and the ship operating method of the present invention, since the EGR operation emergency stop mode for closing the EGR valve at the time of input of the crash operation signal is formed, harmful substances in the exhaust gas can be reduced, and the crash operation is performed. The output in the reverse direction to the traveling direction at the time can be sufficiently secured.

1 is a schematic configuration diagram showing an EGR system according to the present embodiment.
2 is a flowchart showing EGR operation stop switching control in the EGR system according to the present embodiment.
3 is a flowchart illustrating EGR stop operation control.
4 is a flowchart showing an EGR driving emergency stop control.
5 is a time chart illustrating EGR operation stop control.
6 is a time chart showing the EGR driving emergency stop control.

EMBODIMENT OF THE INVENTION Below, with reference to an accompanying drawing, preferable embodiment of the EGR system and ship operating method which concern on this invention is described in detail. In addition, this invention is not limited by this embodiment, and when there are multiple embodiment, it also includes what comprises each embodiment combining.

1 is a schematic configuration diagram showing an EGR system according to the present embodiment.

As shown in FIG. 1 in this embodiment, the marine diesel engine 10 is equipped with the engine main body 11, the supercharger 12, and the EGR system 13. As shown in FIG.

Although not shown in figure, the engine main body 11 is a propulsion engine (main engine) which drives and rotates a propeller for propulsion via a propeller shaft. The engine main body 11 is a uniflow small exhaust type diesel engine, which is a two-stroke diesel engine, in which the flow of the intake and exhaust in the cylinder is set in one direction from the lower side to the upper side so as to eliminate residual gas. will be. The engine main body 11 includes a plurality of cylinders (combustion chamber) 21 in which the piston moves up and down, a scavenging trunk 22 in communication with the cylinder 21, and an exhaust manifold 23 in communication with the cylinder 21. Have In the engine main body 11, the air supply line G1 is connected to the scavenging trunk 22, and the exhaust line G2 is connected to the exhaust manifold 23.

The supercharger 12 is configured so that the compressor (C) 31 and the turbine (T) 32 are integrally rotated by the rotation shaft 33. The turbocharger 12 rotates the turbine 32 by the exhaust gas discharged from the exhaust line G2 of the engine main body 11, the rotation of the turbine 32 is transmitted by the rotary shaft 33, and the compressor ( 31 rotates, and this compressor 31 compresses combustion gas (air and / or recycle gas), and supplies it to the engine main body 11 from the air supply line G1.

The compressor 31 is further provided with a suction line G3 for sucking air (atmosphere) from the outside, and an exhaust gas recirculation line G7 through which the recirculating gas is sent by the EGR blower 44, and the EGR is provided. In operation, the combustion gas is generated by mixing the air from the suction line G3 and the recycle gas from the exhaust gas recirculation line G7 in a mixer (not shown). In addition, the mixer does not necessarily need to be a device having only a function of mixing recycle gas and air, and may be formed as a mixer having a function described above in a silencer (not shown) attached to the compressor 31.

The turbine 32 is connected with the exhaust line G4 which discharges the exhaust gas which rotated this turbine 32, and this exhaust line G4 is a chimney (funnel) via the exhaust gas processing apparatus which is not shown in figure. )

The EGR system 13 includes exhaust gas recirculation lines G5, G6 and G7, an EGR inlet valve (opening and closing valve) 41, a scrubber 42, a demister unit 43, and an EGR blower (blower). / C) 44, an EGR outlet valve (opening and closing valve) 45, a purge device 46, and a control device 80 are provided. When the EGR system 13 mixes the recycle gas which is a part of the exhaust gas discharged from the engine main body 11 with air, it compresses by the supercharger 12, and recycles it to the engine main body 11 as a combustion gas. This is to remove harmful substances from this recycle gas.

In addition, in the following description, exhaust gas is discharged from the engine main body 11 to the exhaust line G2, and is discharged | emitted from the exhaust line G4 to the outside, and recirculating gas is separated from the exhaust line G4. Part of the exhaust gas is returned to the engine main body 11 by the exhaust gas recirculation lines G5, G6, and G7.

That is, the exhaust gas recirculation line G5 is connected to the intermediate part so that one end may branch off from the exhaust line G4, and the other end is connected to the scrubber 42. The exhaust gas recirculation line G5 is provided with the EGR inlet valve 41. The EGR inlet valve 41 opens / closes the exhaust gas recirculation line G5 to turn on / off the exhaust gas classified from the exhaust line G4 to the exhaust gas recirculation line G5. Moreover, you may make it adjust the flow volume of the exhaust gas which passes through the exhaust gas recirculation line G5, using the EGR inlet valve 41 as a flow volume adjusting valve.

The scrubber 42 removes harmful substances, such as particulates (PM), such as SOx and dust which are contained by injecting water (washing liquid) to the recycle gas. The scrubber 42 is provided with the throat part 51 which forms a hollow shape, the venturi part 52 in which exhaust gas is introduce | transduced, and the expansion part 53. As shown in FIG. The scrubber 42 is provided with the water injection part 54 which injects water with respect to the recycle gas introduce | transduced into the venturi part 52. As shown in FIG. The scrubber 42 is connected to an exhaust gas recirculation line G5 through which the recirculation gas is introduced into the venturi part 52, and the recirculation gas and the mist (drainage) from which harmful substances have been removed are expanded to the expansion part 53. The exhaust gas recirculation line G6 to discharge is connected. In addition, although the banturi type | mold is employ | adopted in this embodiment, it is not limited to this structure.

The exhaust gas recirculation line G6 has one end connected to the scrubber 42 and the other end connected to the EGR blower 44. In this case, the demister unit 43 is arrange | positioned on the path | route of the exhaust gas recirculation line G6. In addition, although the scrubber 42 and the demister unit 43 were comprised independently, you may comprise integrally.

The demister unit 43 separates the recycle gas and mist (drainage) from which harmful substances were removed by water injection. The demister unit 43 is provided with the demister cleaning apparatus 56 which wash | cleans a demister main body (not shown). Moreover, the demister unit 43 is provided with the waste_water | drain circulation line W1 which circulates wastewater to the water injection part 54 of the scrubber 42. As shown in FIG. The drain circulation line W1 includes a hold tank 57 for temporarily storing waste water, a supply pump 58 for supplying waste water, and a water treatment device for removing harmful substances from the waste water (for example, centrifugal discharge). Separator 59 is formed.

The EGR blower 44 guides the recycle gas in the scrubber 42 from the exhaust gas recirculation line G6 to the demister unit 43, and is driven by the electric motor M 64.

The exhaust gas recirculation line G7 has one end connected to the EGR blower 44, the other end connected to the compressor 31 of the supercharger 12 via a mixer (not shown), and the EGR blower 44. By this, the recycle gas is sent to the compressor 31. The exhaust gas recirculation line G7 is provided with the EGR outlet valve 45. The EGR outlet valve 45 opens and closes the exhaust gas recirculation line G7 to send the recycle gas of the exhaust gas recirculation line G7 to the compressor 31. In addition, you may make it adjust the flow volume of the recycle gas which passes through the exhaust gas recirculation line G7 using the EGR outlet valve 45 as a flow volume adjusting valve.

Moreover, the air cooler (cooler) 65 is formed in the air supply line G1. This air cooler 65 cools this combustion gas by heat-exchanging with the combustion gas and cooling water which were compressed by the compressor 31, and became high temperature.

The purge device 46 discharges the residual corrosion component by supplying purge gas (air) to the exhaust gas recirculation lines G5, G6, and G7. The purge device 46 includes a purge gas supply line G11 and a purge valve 71. In this case, the exhaust gas recirculation lines G5, G6 and G7 and the air supply line G1 function as purge gas discharge lines. The purge device 46 supplies the purge gas from the purge gas supply line G11 and discharges the purge gas together with the corrosion component from the exhaust gas recirculation line G7. The exhaust gas recirculation lines G5, G6, and G7 are connected to the engine main body 11 via the air supply line G1.

One end of the purge gas supply line G11 is open to the atmosphere, and the other end thereof is in communication with the intermediate portion of the exhaust gas recirculation line G5. That is, the other end of the purge gas supply line G11 is connected to the middle portion of the exhaust gas recirculation line G5 between the EGR inlet valve 41 and the scrubber 42. In addition, one end of the purge gas supply line G11 may be connected to a compressed air supply source. The compressed air supply source consists of a compressor, a pressure storage tank, etc., for example, By collecting the compressed air produced | generated by the compressor in a pressure storage tank, compressed air can be supplied to the various apparatuses used in a ship.

The purge valve 71 can open and close the purge gas supply line G11. Therefore, when the EGR inlet valve 41 is closed and the purge valve 71 is opened, outside air (air) as the purge gas is sucked from one end of the purge gas supply line G11, and this purge gas supply line ( It is possible to supply to the exhaust gas recirculation line G5 via G11).

The control device 80 is capable of controlling the operation of the EGR inlet valve 41, the EGR blower 44, the EGR outlet valve 45, the feed pump 58, the water treatment device 59, and the purge valve 71. It is. That is, the control apparatus 80 is EGR inlet valve 41, EGR blower 44, EGR outlet valve 45, supply pump 58, the water treatment apparatus 59 according to the operating state (operation area) of a ship. The operation of the purge valve 71 is controlled.

The control device 80 stops the EGR operation by the EGR system 13 when the current sea area of the ship is outside the ECA (NOx regulated sea area) that regulates the emission of NOx. In short, the EGR inlet valve 41, the EGR outlet valve 45, and the purge valve 71 are closed, and the driving of the EGR blower 44, the supply pump 58, and the water treatment device 59 is stopped. Then, the exhaust gas from the engine main body 11 is discharged | emitted to the exterior from the exhaust line G4.

On the other hand, the control apparatus 80 starts EGR operation by the EGR system 13, if the current sea area of a ship is in ECA (NOx regulated sea area) which regulates discharge | emission of NOx. In short, the EGR inlet valve 41 and the EGR outlet valve 45 are opened, and the drive of the EGR blower 44, the supply pump 58, and the water treatment device 59 is started. Then, a part of the exhaust gas discharged from the engine main body 11 is supplied from the exhaust line G4 to the exhaust gas recirculation lines G5, G6 and G7.

And the control apparatus 80 switches to the EGR operation stop state from the EGR operation state by the EGR system 13, when the operation sea area of the current ship moves to outside the ECA from ECA. That is, while reducing the rotation speed of the EGR blower 44, while closing the EGR inlet valve 41, the purge valve 71 is opened. Then, the exhaust gas from the engine main body 11 is discharged | emitted to the exterior from the exhaust line G4. In addition, the air supplied from the purge gas supply line G11 to the exhaust gas recirculation line G5 passes through the exhaust gas recirculation lines G5, G6, and G7 and the air supply line G1. It is sent to (22).

Here, the specific effect | action by the EGR system 13 is demonstrated.

When the combustion gas is supplied from the scavenging trunk 22 into the cylinder 21, the engine main body 11 is compressed by the piston, and the fuel is injected into the combustion gas to spontaneously ignite and combust. . The generated combustion gas is discharged from the exhaust manifold 23 to the exhaust line G2 as exhaust gas. The exhaust gas discharged from the engine main body 11 is discharged to the exhaust line G4 after the turbine 32 in the supercharger 12 is rotated, and when the EGR inlet valve 41 is closed, the entire exhaust gas is exhausted. The amount is discharged to the outside from the exhaust line G4.

On the other hand, when the EGR inlet valve 41 and the EGR outlet valve 45 are open, a part of the exhaust gas flows from the exhaust line G4 to the exhaust gas recirculation line G5. As for the recycle gas which is a part of the waste gas which flowed in the waste gas recycle line G5, the harmful substance is removed by the scrubber 42. As shown in FIG. That is, the scrubber 42 is sprayed with water from the water jetting section 54 when the recycle gas passes through the venturi section 52 at high speed, so that the scrubber 42 is cooled by the water and fine particles such as SOx or dust sold out. PM falls with the water and is removed.

The exhaust gas from which harmful substances have been removed by the scrubber 42 is discharged to the exhaust gas recirculation line G6, and after the recycle gas and the mist (drainage) are separated by the demister unit 43, the EGR blower 44. ) And the exhaust gas recirculation line G7 to the supercharger 12. And this recycle gas mixes with the air sucked in from the suction line G3, becomes a gas for combustion, is compressed by the compressor 31 of the supercharger 12, and is cooled by the air cooler 65, It is supplied to the engine main body 11 from the air supply line G1.

However, when the ship is sailing forward, for example, when another ship crosses the front, it is necessary to emergency stop the hull in order to avoid danger. In particular, in the case of a relatively large ship, a crash aston or a crash head which immediately reverses the rotational direction of the internal combustion engine is implemented to emergency stop the ship. By the way, when the marine diesel engine 10 is performing EGR operation, since the combustion gas which mixed recycle gas with air was supplied in the cylinder, oxygen in a cylinder is in a lean state. Therefore, when a crash astern or a crash response is performed during the EGR operation, the oxygen in the cylinder is in a lean state, whereby the flammability deteriorates and the output on the reverse side may be lowered.

Therefore, in the present embodiment, when the crash aston or the crash answer is performed during the EGR operation, the EGR operation is urgently stopped. That is, when transitioning from the operation state of the EGR system 13 to the stop state, the control device 80 includes an EGR operation stop mode for completely stopping the operation of the EGR system 13 at the time of input of the EGR operation stop signal, EGR operation emergency stop mode which makes the operation of EGR system 13 emergency stop at the time of a crash operation signal input is enabled.

By operating the steering wheel (not shown), the ship can switch between forward and backward, stop, and navigation speeds. Navigation Full Ahead (Navigation Full Ahead: forward speed to navigation (commercial) speed) from the forward side, Full Ahead (Full Ahead: forward speed to speed within a port) Revolutions), Half Ahead (Half Ahead), Slow Ahead (Slow Ahead: Forward Slow Speed to Harbor Inner Speed), Dead Slower There is a dead slow ahead, the slowest forward speed to the speed of the port, and a cycle stop. Then, from the stop of the cycle to the reverse side, the dead slow aston (lowest reverse speed), slow astern (low reverse speed), half aston (half reverse speed) , Full astern (reverse full speed). The crew can switch the ship's forward, backward, stop, and navigation speeds by switching the steering wheel to each position.

Here, the crash aston is to operate in full aston from any one of the forward head, the half head, the slow head, and the dead slow head. In addition, Crash Ahead is a full Ahead from any one of Dead Slow Aston, Slow Aston, Half Aston, and Pool Aston. In the present embodiment, the crash operation signal described above is output to the control device 80 during operation between the pullback head and the reverse side by the steering wheel, or during operation between the pull aston and the forward side. Will be.

Hereinafter, operation stop control in the EGR system of the present embodiment will be described. 2 is a flowchart showing the EGR operation stop switching control in the EGR system of the present embodiment, FIG. 3 is a flowchart showing the EGR operation stop control, and FIG. 4 is a flowchart showing the EGR operation emergency stop control. .

In the operation stop control in the EGR system of the present embodiment, as shown in FIGS. 1 and 2, when the EGR system 13 is in operation in step S11, the control device 80 performs a crash operation in step S12. It is determined whether or not a signal has been input, that is, whether a crash astonish or a crash answer has been implemented. If it is determined (No) that no crash operation signal is input, the process proceeds to step S13. In step S13, the control apparatus 80 determines whether the EGR operation stop signal was input. This EGR driving stop signal is output when the EGR driving stop button (not shown) is pressed, and is input to the control device 80 by the operation of the EGR driving stop button. If it is determined (No) that the EGR operation stop signal is not input, it exits from this routine without processing anything.

On the other hand, if it is determined (Yes) that the EGR operation stop signal is input to the control device 80 by the operation of the EGR operation stop button in step S13, the process proceeds to step S14, and the control device 80 moves to the EGR operation stop mode. Start the sequence of. If it is determined (Yes) that the crash operation signal is input in step S12, the routine advances to step S15, and the control device 80 starts the sequence of the EGR operation emergency stop mode.

First, the processing of the EGR operation stop mode will be described. As shown in FIG. 1 and FIG. 3, the EGR operation stop sequence is started in step S21, and in step S22, the control device 80 decreases the rotation speed of the EGR blower 44, and the EGR blower 44 in step S23. It is determined whether or not the number of revolutions of?) Is equal to or less than the preset number of revolutions. Here, when it waits (No) until the rotation speed of the EGR blower 44 becomes below the preset rotation speed, and it is determined (Yes) that the rotation speed of the EGR blower 44 became below the preset rotation speed, it will transfer to step S27. .

Moreover, the control apparatus 80 starts the closing operation of the EGR inlet valve 41 in step S24, and determines whether the opening degree of the EGR inlet valve 41 became below the preset opening degree in step S25. Here, when it waits (No) until the opening degree of the EGR inlet valve 41 becomes below a setting opening degree, and it is determined (Yes) that the opening degree of the EGR inlet valve 41 becomes below a setting opening degree, it is EGR inlet valve 41 ) Is kept in a fine open state, and the flow proceeds to Step S27.

In step S26, the rotation speed of the EGR blower 44 becomes below the set rotation speed in step S23, and it waits (No) until the opening degree of the EGR inlet valve 41 becomes below the set opening degree in step S25, and EGR If it is determined that the rotation speed of the blower 44 is equal to or less than the set rotational speed and the opening degree of the EGR inlet valve 41 is equal to or less than the set opening degree, the flow proceeds to step S27.

In step S27, the control device 80 starts the opening operation of the purge valve 71. In step S28, it is determined whether the opening degree of the purge valve 71 is fully opened. Here, when it waits (No) until the opening degree of the purge valve 71 becomes a total opening, and it is determined (Yes) that the opening degree of the purge valve 71 is opened, the EGR inlet valve 41 is carried out in step S29. The closing operation | movement of is resumed and it is determined in step S30 whether the opening degree of the EGR inlet valve 41 became below the preset opening degree (almost total closing). Here, when it is determined that the opening degree of the EGR inlet valve 41 is closed (Yes) until the opening degree of the EGR inlet valve 41 becomes full closing (Yes), the exhaust gas recirculation line is made in step S31. The purge process of (G5) is executed for a predetermined time specified in advance.

That is, since the EGR inlet valve 41 is closed to a predetermined opening degree and the purge valve 71 is opened, the air (atmosphere) as the purge gas is exhaust gas recirculation lines G5, G6 and G7, the compressor 31, It communicates with the scavenging trunk 22 of the engine main body 11 via the air supply line G1. In addition, in the exhaust gas recirculation lines G5, G6, and G7, the EGR blower 44 is formed in the middle portion, and the EGR blower 44 is driven at low rotation, so that the gas flow to the scavenging trunk 22 side. This works. Therefore, the corrosion component which remained in the exhaust gas recirculation line G5, G6, G7 is removed by the air from the purge gas supply line G11, and the purge gas containing a corrosion component is scavenged trunk 22 Is sent to.

In step S32, the control device 80 determines whether or not purge is completed after a prescribed time has elapsed since the purge valve 71 is opened. Here, it is determined whether the predetermined prescribed time has elapsed since it is determined that the opening degree of the EGR inlet valve 41 is completely closed. In short, the purge process of the exhaust gas recirculation lines G5, G6, and G7 is executed until the prescribed time elapses. The purge processing time (regulation time) of this exhaust gas recirculation line G5, G6, G7 is, for example, the volume (volume) of the apparatus or piping which perform a purge process, and the purge gas supply line G11 per unit time. It is set based on the amount of air received, the concentration of corrosion components in the purge region, and the like.

The purge process of the exhaust gas recirculation lines G5, G6, and G7 is completed, and the control device 80 waits until the prescribed time elapses after it is determined that the opening degree of the EGR inlet valve 41 is completely closed ( No), and if it is determined (Yes) that the prescribed time has elapsed since it is determined that the opening degree of the EGR inlet valve 41 is completely closed, the drive of the EGR blower 44 is stopped in step S33. Then, the control apparatus 80 closes the purge valve 71 in step S34, and closes the EGR outlet valve 45 in step S35. Thereafter, when the demister cleaning device 56 is operated in step S36 to clean the demister unit 43, and the scrubber 42 is stopped in step S37, the EGR operation is completely stopped in step S38. At the time of stopping this scrubber 42, it is the stop of the water injection by the water injection part 54 by the drive stop of the supply pump 58 and the water treatment apparatus 59. FIG.

In addition, when the operation of the engine main body 11 is stopped during the purge process of the exhaust gas recirculation lines G5, G6 and G7, the purge gas containing the corrosion component remaining in the exhaust gas recirculation lines G5, G6 and G7. Becomes difficult to send to the scavenging trunk 22. For this reason, in the present embodiment, for example, at the time of arrival at the port, the EGR operation is completely stopped at the previous stage.

Next, the processing of the EGR driving emergency stop mode will be described. As shown to FIG. 1 and FIG. 4, the EGR operation emergency stop sequence is started in step S51, and the control apparatus 80 stops the drive of the EGR blower 44 in step S52. Moreover, the control apparatus 80 starts the closing operation of the EGR inlet valve 41 in step S53, and starts the closing operation of the EGR outlet valve 45 in step S54. Then, the EGR operation is emergency stopped in step S55. At this time, the exhaust gas discharged from the engine main body 11 is discharged to the exhaust line G4 after the turbine 32 in the supercharger 12 is rotated, and the EGR inlet valve 41 is closed. Thereby, the whole quantity is discharged | emitted from the exhaust line G4 to the exterior, and is not supplied to the engine main body 11 by any means. Therefore, since the EGR operation | movement stops and the recycle gas is not supplied in the cylinder, the marine diesel engine 10 will not become an oxygen lean state in a cylinder. Then, with respect to the implementation of the crash astern, even if the engine speed decreases, the ignition property does not deteriorate, and the output on the reverse side is sufficiently secured.

Then, when the emergency stop operation of a ship is canceled in the state in which EGR operation by the EGR system 13 was emergency-stopped, output of a crash operation signal will be stopped and an EGR operation start signal will be output. When the EGR operation start signal is input, the control apparatus 80 resumes EGR operation by the EGR system 13. At this time, the control device 80 opens the EGR inlet valve 41 and the EGR outlet valve 45, and starts driving of the EGR blower 44.

In addition, the operation of various devices in the EGR operation stop mode and the EGR operation emergency stop mode by the EGR system 13 will be described. 5 is a time chart showing the EGR driving stop control, and FIG. 6 is a time chart showing the EGR driving emergency stop control.

In the EGR operation stop mode, as shown in FIG. 1 and FIG. 5, when the EGR operation stop mode is started at time t1, the closing operation of the EGR inlet valve 41 is started to rotate the EGR blower 44. The number decreases. When the EGR inlet valve 41 is finely opened at the time t2, and the rotation speed of the EGR blower 44 is a predetermined rotation speed, the opening operation of the purge valve 71 is started to exhaust gas recirculation lines G5 and G6. , Purge process of G7) is started.

When the opening degree of the purge valve 71 becomes full open, the EGR inlet valve 41 is closed again at time t3, and is fully closed at time t4. When the prescribed time for executing the purge process elapses at time t5, the purge valve 71 is closed, the driving of the EGR blower 44 is stopped, and the EGR outlet valve 45 is closed. At this time, the demister cleaning device 56 is operated to clean the demister unit 43, and the EGR operation is completely stopped by stopping the driving of the water treatment device 59 of the scrubber 42 at time t6.

In the EGR driving emergency stop mode, as shown in FIGS. 1 and 6, when the crash operation signal is input at time t11, the EGR driving emergency stop mode is started. That is, the engine load decreases, and at the same time, the closing operation of the EGR inlet valve 41 is started, the EGR outlet valve 45 is closed, and the rotation speed of the EGR blower 44 further decreases. Here, the EGR operation is stopped emergencyly. 6, the dashed-dotted line of a periodic load shows the periodic load 0, and the upper side is a periodic load of a forward side, and the lower side is a periodic load of a reverse side.

After that, the engine load on the reverse side becomes maximum at time t12, the engine load on the reverse side starts to decrease at time t13, and when the engine load becomes zero at time t14, the output of the crash operation signal is lost. Stop. Then, after the engine load in the forward rises, the EGR operation start mode is executed at time t15. That is, while the EGR inlet valve 41 and the EGR outlet valve 45 are opened, the drive of the EGR blower 44 is started. And the EGR inlet valve 41 is fully open at time t16, and rotation of the EGR blower 44 becomes constant.

Thus, in the EGR system of this embodiment, the exhaust gas recirculation lines G5, G6, G7, the EGR inlet valve 41 and the EGR outlet valve 45, the scrubber 42, and the EGR inlet valve 41 are described. And a control device 80 capable of opening and closing control of the EGR outlet valve 45 and driving control of the scrubber 42, wherein the control device 80 includes an EGR inlet valve 41 at the time of input of a crash operation signal. And the EGR operation emergency stop mode in which the EGR outlet valve 45 is closed.

Therefore, when the EGR operation emergency stop mode is executed, the EGR operation is stopped early by closing the EGR inlet valve 41 and the EGR outlet valve 45, so that even if a crash astern or a crash answer is performed, Since it does not become an air lean state, the ignition does not deteriorate and the engine output does not decrease. As a result, since a sufficient output in the reverse direction to the traveling direction can be secured at the time of the crash operation, the vessel can be stopped quickly.

In the EGR system of this embodiment, the purge apparatus 46 which supplies a purge gas to exhaust gas recirculation lines G5, G6, and G7 and discharge | eliminates the residual corrosion component is provided, and the control apparatus 80 operates EGR When the stop mode is executed, the EGR inlet valve 41 and the EGR outlet valve 45 are closed to operate the purge device 46, and when the EGR operation emergency stop mode is executed, the EGR inlet valve 41 and the EGR outlet valve are performed. The 45 is abolished and the drive of the scrubber 42 and the operation of the purge device 46 are stopped. Therefore, when the EGR operation stop mode is executed, the introduction of recycle gas into the exhaust gas recirculation lines G5, G6 and G7 is stopped, and the purge gas is supplied to the exhaust gas recirculation lines G5, G6 and G7. Corrosion components remaining in the exhaust gas recirculation lines G5, G6 and G7 are discharged together with the purge gas. On the other hand, when the EGR operation emergency stop mode is executed, the EGR operation can be emergency stopped early by closing the EGR inlet valve 41 and the EGR outlet valve 45 and not driving the purge device 46.

In the EGR system of the present embodiment, the crash operation signal is output to the control device 80 at the time of operation between the pull head and the reverse side by the steering wheel, or at the time of operation between the pull aston and the forward side. . Thus, when the crash head and the crash astern are executed, the output in the reverse direction to the traveling direction can be sufficiently secured.

In the EGR system of the present embodiment, the control device 80 simultaneously closes the EGR inlet valve 41 and the EGR outlet valve 45 when the EGR operation emergency stop mode is executed, and the EGR blower 44 Stops driving. Therefore, the introduction of the exhaust gas into the exhaust gas recirculation lines G5, G6 and G7 and the supply of the recycle gas to the engine main body 11 can be stopped immediately, and the engine output can be stabilized at an early stage.

In the EGR system of the present embodiment, the purge device 46 opens and closes the purge gas supply line G11 for supplying the purge gas to the exhaust gas recirculation lines G5, G6, and G7 and the purge gas supply line G11. A purge valve 71 is formed and an air supply line G1 as a purge gas discharge line for discharging the corrosion component remaining with the purge gas. Therefore, when the EGR operation stop mode is executed, the purge gas is supplied from the purge gas supply line G11 to the exhaust gas recirculation lines G5, G6, and G7 by opening the purge valve 71, so that the purge gas and the corrosion component It is discharged | emitted from this air supply line G1, and supply of purge gas and discharge of purge gas and a corrosive component can be performed suitably.

In the ship operating method of the present embodiment, the engine main body 11 for propulsion and the recirculating gas which is a part of the exhaust gas discharged from the engine main body 11 are mixed with air and then the engine main body ( 11) The EGR system 13 to be recycled is formed, and the operation of the EGR system 13 is stopped when the crash aston or the crash head is executed. Therefore, even if a crash astonish or a crash answer is applied, the air lean state in a cylinder is eliminated, and flammability does not deteriorate and engine output does not fall. As a result, it is possible to reduce the harmful substances in the exhaust gas and to sufficiently secure the output in the reverse direction to the traveling direction during the crash operation.

In the above-described embodiment, the purge gas supply line G11 and the purge valve 71 are formed in the exhaust gas recirculation line G5 as the purge device 46, and the recirculation gas and the purge gas are supplied to the engine main body 11. Although it is comprised so that it may discharge | emit, it is not limited to this structure. For example, the recycle gas and the purge gas may be discharged from the exhaust line G4 to the outside. Moreover, you may provide a purge gas supply line and a purge valve in exhaust gas recirculation line G7. Moreover, you may use the gas for combustion supplied from the air supply line G1 to the engine main body as a purge gas.

Moreover, although the above-mentioned embodiment demonstrated using the main engine as a marine diesel engine, it is applicable also to the diesel engine used as a generator.

10: marine diesel engine
11: engine body
12: supercharger
13: EGR system
41: EGR inlet valve
42: scrubber
43: Demister Unit
44: EGR blower
45: EGR outlet valve
46: purge device
54: water jet
56: demister cleaning device
58: feeding pump
59: water treatment device
71: purge valve
G1: air supply line
G2, G4: exhaust line
G3: suction line
G5, G6, G7: exhaust gas recirculation line
G11: Purge Gas Supply Line
W1: drainage circulation line

Claims (6)

An exhaust gas recirculation line for recirculating a portion of the exhaust gas discharged from the engine as combustion gas to the engine;
An EGR valve formed in the exhaust gas recirculation line,
A scrubber for injecting a liquid into the combustion gas flowing through the exhaust gas recirculation line;
A control device for controlling the EGR valve and the scrubber,
The control device includes an EGR operation emergency stop mode that closes the EGR valve upon input of a crash operation signal and continues driving the scrubber, and closes the EGR valve upon input of an EGR operation stop signal, and then the The EGR system characterized by being able to execute the EGR operation stop mode which stops driving a scrubber. The method of claim 1,
A purge device for supplying purge gas to the exhaust gas recirculation line,
The control device further controls the purge device,
The EGR operation stop mode for closing the EGR valve at the time of input of the EGR operation stop signal and operating the purge device and then stopping the drive of the scrubber, and the EGR valve at the input of the crash operation signal. And an EGR operation emergency stop mode for closing and stopping the operation of the purge device. The method of claim 2,
The purge device includes a purge gas supply line for supplying the purge gas to the exhaust gas recirculation line, a purge valve for opening and closing the purge gas supply line, and a purge gas discharge line for discharging the purge gas. EGR system. The method according to any one of claims 1 to 3,
When the engine's forward rotation speed is greater than or equal to the setting speed of the crash determination during the reverse command operation by the steering wheel, or when the engine's forward rotation speed is greater than or equal to the setting speed of the crash determination during the forward side command operation by the steering wheel, Or, when the crash operation is arbitrarily performed in addition to the crash determination, the crash operation signal is output to the control device. The method according to any one of claims 1 to 3,
The EGR valve includes an EGR inlet valve disposed upstream of the flow direction of the combustion gas from the scrubber in the exhaust gas recirculation line, and the combustion gas than the scrubber in the exhaust gas recirculation line. And an EGR outlet valve disposed downstream of the flow direction, the flow direction of the combustion gas being downstream of the flow direction of the combustion gas from the scrubber in the exhaust gas recirculation line, and from the EGR outlet valve. A blower is formed upstream of the
And the control device closes the EGR inlet valve and the EGR outlet valve when the EGR operation emergency stop mode is executed, and stops the driving of the blower. Engine for propulsion,
In a ship operating method comprising an EGR system for recycling a part of the exhaust gas discharged from the engine as the combustion gas to the engine,
The operation method of the ship characterized by stopping the operation of the EGR system according to any one of claims 1 to 3 at the time of the crash astonish or the crashhead.

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