KR20160051607A - Control method for a fast reversal of a reciprocating piston internal combustion engine - Google Patents

Abstract

The present invention relates to a control method to rapidly reverse or brake a rotation in the first rotation direction of a crank shaft in a reciprocal type piston internal combustion engine which is a uniflow scavenging type large two-stroke diesel engine which operates at a low speed. The reciprocal type piston internal combustion engine includes a cylinder where a reciprocating piston is arranged to move back and forth between a top dead center corresponding to the crank angle of 180° and a bottom dead center corresponding to the crank angle ranging from 0° or 360°. The reciprocal type piston internal combustion engine also includes an outlet valve which is able to operate hydraulically through hydraulic valve devices by a hydraulic medium and desirably by hydraulic oil under a predetermined opening pressure. According to the present invention, a first outlet valve is automatically opened by the hydraulic valve devices at a second crank angle when penetrating a first cylinder through the top dead center of a first piston by stopping a fuel supply into the reciprocal type piston internal combustion engine in a brake step and providing the hydraulic medium under a predetermined maximum opening pressure of the hydraulic valve devices of the first outlet valve of the first cylinder at a first crank angle in a section of the top head center of the first piston related to the first cylinder.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a control method for rapidly reversing a reciprocating piston internal combustion engine,

The present invention relates to a control for rapidly reversing or braking a rotation in a first rotation direction of a crankshaft of a reciprocating piston internal combustion engine, which is a single-sweep large two-stroke diesel engine operating in particular at low speed, according to the preamble of independent claim 1 ≪ / RTI >

Large-size diesel engines are mainly used as marine drive units, or mainly in fixed operation, for example for driving large generators for generating electrical energy. In this regard, the organs typically operate over a significant period of time with permanent operation, requiring a high degree of operational reliability and effectiveness. Therefore, especially the long service intervals, low wear, and economical handling of fuel and working materials are the primary criteria for the operator to operate the machine. The piston operating behavior of such a large bore low speed diesel engine is, amongst other things, a determinant of the duration and effectiveness of the service interval, and of lubricating oil consumption, as well as of operating costs and thus of operating efficiency.

At all times, in marine vessels, in the event of an emergency, in the shortest possible time, and therefore braking the vessel at the maximum speed as short as possible, or the propeller is rotated in the opposite direction as soon as possible and the vessel continues its voyage in the opposite direction as soon as possible There is a need and desire to reverse the institution as quickly as possible. Although various trial and test processes have been available for this purpose for a relatively long time for a relatively small motor vessel or motor boat and the reversal can be achieved simply through the predominantly transmission, the "emergency braking" Rapid braking at full speed with large ships equipped with a large reciprocating piston internal combustion engine, such as a large two-stroke diesel engine, has not been largely solved before. In addition to the braking of the ship, this concerns a problem that is closely related to the problem of a rapid reversal of the engine in the opposite direction of rotation from one rotation direction to the other.

The reason for this is that due to the enormous size and power of the engine, the rational use of the clutch and / or transmission between the engine and the propeller is such that the propeller rotates in a crankshaft of a large- This is a problem that should not be underestimated, especially with a single-swage large two-stroke diesel engine operating at low speeds, since it is virtually excluded to be fixedly connected.

Thus, the configuration of the drive is obviously substantially simpler than the drive in which the transmission is provided between the propeller and the engine. However, a disadvantage of such a configuration without the transmission and clutch is that the propeller is permanently fixedly connected to the engine at all times, i. E. In every operating state, so that at least in the operating state of the engine, , And can not be separated from the organ. That is, in the operating state where the engine is stopped to stop the braking of the ship, which essentially means that the fuel supply to the engine is actually stopped, the ship does not immediately stop, but is initially stopped due to the massive inertial mass of the ship. It will continue, and will only slow down gradually.

At this point, the propeller is no longer driven explicitly by the engine, but the propeller is driven by progression through the water at a constant relative speed between the propeller and the water. However, since the propeller is rotatably fixed to the engine and can not be connected and separated from the engine, the engine is also driven by the propeller in this operating state. This nevertheless means that since the engine is driven by the propeller, after the stop of the fuel supply, the motor continues to rotate in its original direction for a considerable period of time.

Acceleration of the braking of the ship or inversion of the direction of movement of the ship can only be achieved in that the engine is restarted in the reversed rotational direction. According to most known marine engines, and especially in the case of a large single-sweep large two-stroke diesel engine, compressed air (also referred to as start-up air), at the appropriate time, i.e. at a suitable crank angle, This is only achieved in that it is pressurized into the cylinder liner at a pressure sufficiently high so as to be restarted in the desired reversed rotational direction by the starting air acting on the cylinder liner.

As described above, due to the enormous force exerted by the propeller through the crankshaft to the piston in the cylinder liner of the engine so that the engine continues to rotate in its original direction despite the stationary fuel supply, the maximum available pressure of the starting air, So that the engine can be set to rotate sufficiently fast in the opposite direction by the starting air so that the engine can eventually be restarted independently in the opposite direction upon reactivation of the fuel supply , The organs can be restarted as soon as possible in the opposite direction. When the engine is restarted in the opposite direction of rotation, the propeller rotatably fixed to the engine is naturally driven in the opposite direction by the engine, so that the braking of the ship can be continued until the movement of the ship finally stops, If desired, it can be accelerated more and more until the ship starts to move in the opposite direction.

The disadvantages of the above and previous conventional processes for braking and reversing the vessel are obvious. On the one hand, since it is necessary to wait for a long time until the ship is sufficiently slowed down sufficiently to allow the drive of the engine through the propeller to be compensated by the starting air, before the engine can be restarted in the opposite direction, In particular, the braking of a ship equipped with a single-sweep type large two-stroke diesel engine operating at low speed requires much time. This still takes a considerable amount of time, and this time requirement is particularly important when the ship is to be braked very quickly, for example in an emergency, in order to reliably and effectively prevent collisions with other ships, icebergs or other obstacles It becomes a big disadvantage. Among them, the famous Titanic disaster, which was unable to stop the ship anymore in the family register, remains in the hearts of the public to this day. Although the Titanic was not driven by a single-stage, large-scale two-stroke diesel engine operating at low speeds, the problem is principally the same.

Attempts have been frequently made to reverse the engine at the earliest possible time by the supply of the starting air to the cylinder liner so that the distance covered by the vessel at rest or reversal of travel is minimized. However, as the engine is driven by the propeller and is operating earlier in the forward direction, more starter air or starter air energy may be required to initiate the reverse in the opposite direction. First, this is costly and energy intensive since the starting air must be generated using the corresponding compressor and stored in the pressure reservoir. In addition, the method creates the risk that the total stored startup air is somewhat consumed and nevertheless it is impossible for the engine to start in the opposite direction. In this situation, it may be necessary to provide additional braking, as new starting air must be provided again and the engine can no longer be started between them again, which can have catastrophic consequences under certain circumstances, Not only can it postpone, it can be a safety hazard.

Therefore, it is an object of the present invention to provide a method and apparatus for an internal combustion engine which is capable of reversing the engine in a reverse direction more effectively and more quickly, especially in a single-swage large two-stroke diesel engine operating at a low speed, It is to provide a method which can be carried out very generally with economical and more energy savings than the reversal of the engine can be ignored and the lethal safety problems known from the technology can be ignored.

The subject matter of the present invention which meets this objective is characterized by the features of independent claim 1.

The dependent claims relate to particularly advantageous embodiments of the present invention.

Accordingly, the present invention relates to a control method for quickly reversing or braking a rotation in a first rotation direction of a crankshaft of a reciprocating piston internal combustion engine, which is a single-sweep type large two-stroke diesel engine operating at a low speed, The internal combustion engine has a cylinder in which a piston which is movable back and forth between a top dead center corresponding to a crank angle of 180 ° and a bottom dead center corresponding to a crank angle of 0 ° or 360 ° respectively, And an outlet valve capable of being hydraulically operated by a hydraulic medium, preferably hydraulic oil, at a predetermined opening pressure through the hydraulic device. According to the present invention, the fuel supply to the reciprocating piston internal combustion engine is stopped in the braking step, and the hydraulic medium is supplied to the first cylinder at the first crank angle at the region of the top dead center position of the first piston associated with the first cylinder At a predetermined maximum opening pressure of the valve hydraulic device of the outlet valve such that the first outlet valve is automatically opened by the valve hydraulic device at the second crank angle upon passage of the first piston through the top dead center position of the first piston Lt; / RTI >

A method whereby the engine, which is a single-sweep large two-stroke diesel engine operating at low speeds, can be reversed more effectively and more rapidly in the opposite direction of rotation, while at the same time providing additional useful startup air savings. do. In a particularly preferred embodiment of the method according to the invention, a re-start in the opposite direction of rotation can be completely initiated without any starting air in the vessel, for example utilizing the braking energy provided to the engine by the propeller , Which not only naturally represents an improvement that can not be underestimated in terms of economy when the method according to the invention is used to reverse or brake the engine of the ship, but also represents a great improvement in terms of safety technology.

In a particularly preferred embodiment for the implementation, the reciprocating piston internal combustion engine is a low-speed, single-flow, large two-stroke diesel engine operating on the vessel of a vessel, for example a container ship with an enormously large engine, Up to 10,000 kW per cylinder or more power per cylinder.

As the person skilled in the art perceives, the piston moves back and forth between the top dead center and the bottom dead center in the cylinder liner in the normal operating state of the reciprocating piston internal combustion engine, and a crankshaft which is operatively fixed and connected to the piston and the propeller Drive the propeller through. In the cylinder cover of the cylinder liner, the outlet valve is hydraulically operated through a valve hydraulic device by a programmable control device, which may in particular include a hydraulic device and an electronic device. In this regard, the crank angle at which the outlet valve is actuated can be predetermined as desired, in particular by the programmable control device. The engine can be started from the standstill by operating the starter air valve or at sufficiently small rotational speeds and the direction of rotation of the engine can be changed.

For a better understanding of the present invention, the normal operating mode of the reciprocating piston internal combustion engine, which is known per se, will again be briefly and schematically recalled below. Within the scope of the present application, the crank angle of 0 DEG or 360 DEG is the same as the bottom dead center (UT), and the crank angle of 180 DEG is the same as the top dead center (OT).

Starting from the bottom dead center corresponding to a crank angle of 0 DEG, the piston first moves in the direction OT corresponding to a crank angle of 180 DEG in the operating state. When the piston is located at a position close to the bottom dead center, the scarring slits are released in the lower region of the cylinder liner, and the outlet valve 5 is opened in the normal operating state. Fresh air is supplied to the combustion space of the cylinder liner through the desired slits and the combustion residues are simultaneously discharged out of the combustion space through the outlet valve by the movement of the piston in the direction toward the top dead center as long as the desired slits are released by the piston And is flushed. When the piston completely passes the scavenging slits so that there is no more communication between the combustion space and the desired slits, the outlet valve will also be closed by the control device at a predetermined crank angle as the crank angle increases. In a further process, the fuel is supplied by the injection valve to the combustion space of the engine, which is formed from the upper cylinder zone, the cylinder cover located above the cylinder zone and the piston base, And subsequently combusted, resulting in an increase in pressure in the combustion space by this energy release.

After passing the top dead center, the piston again moves in a direction toward the bottom dead center corresponding to a crank angle of 360 [deg.]. In normal operating and moving conditions of the ship, the outlet valve is then opened again and the new working cycle of the cylinder is initiated at a crank angle much greater than 180 °.

When the ship is to be braked, the reciprocating piston internal combustion engine will also be set to a different operating state for braking or reversing in previously known ways, particularly when the ship must be braked within a short distance as far as possible in an emergency. In the first step, it is known to interrupt the supply of fuel into the cylinder liners of the reciprocating piston internal combustion engine. It is first achieved that the rotation speed of the engine is lowered by the interruption of the fuel supply and the first gentle deceleration of the ship is generated. If no further action is taken, the speed of the ship is substantially reduced due to the friction of the ship in water. This friction is generally relatively small to only reduce the speed of the ship very slowly. The propeller, which is no longer driven by the reciprocating piston internal combustion engine after the fuel supply has been stopped, is driven by the kinetic energy present in the vessel, as in the case of a turbine, and is rotationally fixed via a crankshaft do.

If the control of the outlet valve is maintained unchanged as in normal operation and as previously done in the prior art, some of the kinetic energy of the vessel is reliably switched to the compression energy of the cylinder at a crank angle of 0 DEG to 180 DEG , This compression energy is almost completely returned back to the ship via the propeller in the form of kinetic energy at the subsequent expansion of the desired air enclosed in the cylinder liner during the movement of the piston from the top dead center to the bottom dead center.

The present invention is based on this recognition and is based on the recognition that the rapid inversion or braking of the engine is only possible by the proper control of the outlet valve and that the braking energy actually delivered to the engine via the propeller is in accordance with the invention If used skillfully, it can be specifically restarted in the opposite direction with no starting air and with at least as little starting air than the startup air previously required in the prior art.

In a preferred embodiment of the control process according to the present invention, the second crank angle is in the range between the top dead center and the bottom dead center of the first piston, after the top dead center of the first piston, at a value of 180 ° to 360 ° Preferably 180 DEG to 225 DEG or 180 DEG to 200 DEG, and particularly preferably 180 DEG to 190 DEG.

To obtain a further improvement of the braking effect at the time of reversal, the first outlet valve has a third crank angle in the region between the bottom dead center of the first piston and the second crank angle to produce a predetermined vacuum in the first cylinder Lt; / RTI >

Depending on the reversal phase of the organ in which this action is taken, two positive effects can be substantially caused.

When a vacuum is generated in the first cylinder in the braking step of the rotation of the reciprocating piston internal combustion engine in the first rotational direction and the third crank angle is selected accordingly, the braking of the rotation of the reciprocating piston internal combustion engine in the first rotational direction Vacuum can be created in the first cylinder by closing the outlet valve with a suitable choice of the third crank angle to assist by the formation of the vacuum. Thereby, at least some suction effect on the piston occurs so as to result in corresponding braking of the piston movement, which further removes kinetic energy from the engine and thus accelerates braking.

On the other hand, in the reversal phase of the reciprocating piston internal combustion engine in which the third crank angle follows the braking phase, a vacuum is created in the first cylinder by the closing of the first outlet valve at the third crank angle, It is also possible that the restart of the reciprocating piston internal combustion engine in the second rotation direction, which is initiated in the second cylinder by the second rotation direction, is assisted by the formation of the vacuum in the first cylinder. This is because the braking suction effect is generated in the first cylinder with respect to the first rotational direction of the engine, so that the re-start of the engine, i.e. the inversion of the engine in the new second rotational direction of the engine, Which means that an early reversal is possible or possibly still necessary, or that the necessary starting air can be minimized or even fully saved.

A further or alternative measure of the method according to the invention is that the first outlet valve is provided at a fourth crank angle between the bottom dead center and the top dead center, preferably after reaching the end of the supply of scavenged air into the cylinder Lt; RTI ID = 0.0 > crank angle. ≪ / RTI >

Even with the last specified action, there will be a situation in which substantially two additional positive effects can result, depending on the reversal phase of the engine in which the closing of the outlet valve is effected at the fourth crank angle.

On the other hand, when the fourth crank angle is selected in the braking phase of the rotation of the reciprocating piston internal combustion engine so that the excess pressure is formed in the first cylinder by closing the first outlet valve at the fourth crank angle, The braking of the rotation of the reciprocating piston internal combustion engine in the engine is assisted by the formation of excess pressure. And, since the kinetic energy is removed from the engine due to the pressure actually generated in the cylinder in which the kinetic energy is converted into the pressure energy, the braking of the engine in the first rotational direction is very effectively assisted.

On the other hand, in the reversing phase of the reciprocating piston internal combustion engine in which the fourth crank angle follows the braking phase, the excess pressure is selected to be formed in the first cylinder by the closing of the first outlet valve at the fourth crank angle, When the excess pressure formed in one cylinder is properly adjusted with the restarting of the reciprocating piston internal combustion engine in the second rotation direction opposite to the first rotation direction by the fuel supply, By the formation of excess pressure in the fluid.

Since the braking pressure effect is generated in the first cylinder with respect to the first rotational direction of the engine, the re-start of the engine, i.e., the inversion of the engine in the new second rotational direction of the engine opposite to the first rotational direction, Or possibly further, the necessary starting air can be minimized or even facilitated or assisted to be fully saved.

In particular, when a reversal has to occur particularly quickly or when there is a need for urgent braking of the ship, for example, or for a very rapid implementation of the method according to the invention, The restoration of the reciprocating piston internal combustion engine in the second rotation direction can be further assisted by naturally introducing a predetermined minimum amount of the starting air into at least one cylinder of the reciprocating piston internal combustion engine, The inversion in the second rotational direction can be further accelerated.

In particular, as well as when there is no need for a very rapid procedure, such as in an emergency, the start-up air is also fed into only part of the cylinders of the reciprocating piston internal combustion engine, preferably in order to assist in restarting in the second rotational direction during the reversing phase May be introduced sequentially into only one selected cylinder, not just any other cylinder.

Even the method according to the invention is advantageous in that, as already mentioned above, the first valve, which is initiated during the reversal phase without the use of startup air, in that the kinetic energy is ideally used and the outlet valve is well controlled so as to be fed back to the engine by the propeller Allowing the restart of the reciprocating piston internal combustion engine in the second rotational direction opposite to the rotational direction to occur completely.

In practice, the reciprocating piston internal combustion engine is provided with a plurality of cylinders which are simultaneously located at different crank angles at least partially in a manner known per se, thereby accelerating or reversing the engine so as to produce a cumulative effect of different actions The measures specified herein may be taken at the same time.

It is understood that the embodiments of the invention disclosed herein may be combined in any suitable manner depending on the specification and that the specific embodiments disclosed should be understood as merely exemplary. Those skilled in the art will readily appreciate the additional advantageous developments of the disclosed embodiments of the present invention and understand that simple additional developments are also naturally covered by the present invention.

Claims (12)

A control method for quickly reversing or braking a rotation of a crankshaft in a first rotation direction of a reciprocating piston internal combustion engine, which is a single-sweep type large two-stroke diesel engine operating at a low speed,
Wherein the reciprocating piston internal combustion engine includes a cylinder in which a piston movable back and forth between a top dead center corresponding to a crank angle of 180 DEG and a bottom dead center corresponding to a crank angle of 0 DEG or 360 DEG is disposed, The engine is provided with an outlet valve which is hydraulically actuatable via valve hydraulic devices by a hydraulic medium, preferably hydraulic oil, at a predetermined opening pressure,
The fuel supply to the reciprocating piston internal combustion engine is stopped in the braking step and the hydraulic medium is supplied to the first outlet valve of the first cylinder at a first crank angle in the region of the top dead center position of the first piston associated with the first cylinder, Wherein said first outlet valve is automatically opened by said valve hydraulic devices at a second crank angle upon passage of said first cylinder through a top dead center position, Wherein the rotation of the crankshaft in the first rotation direction of the reciprocating piston internal combustion engine is reversed or braked. The method according to claim 1,
The second crank angle is set to a value of 180 ° to 360 °, preferably in a range of 180 ° to 225 °, in a range between the top dead center and the bottom dead point of the first piston after the top dead center of the first piston, Of the crankshaft of the reciprocating piston internal combustion engine is set at a second crank angle of 180 DEG to 190 DEG and particularly preferably 180 DEG to 190 DEG, A control method for reversing or braking. 3. The method according to claim 1 or 2,
Characterized in that the first outlet valve is closed again at a third crank angle in the region between the bottom crank point of the first piston and the second crank angle to create a predetermined vacuum in the first cylinder A control method for rapidly reversing or braking a rotation of a crankshaft of a piston internal combustion engine in a first rotational direction. The method of claim 3,
Wherein said third crank angle is selected such that in said braking phase of rotation of said reciprocating piston internal combustion engine in said first rotational direction a vacuum is created in said first cylinder by closing said first outlet valve at said third crank angle Characterized in that the rotation of the reciprocating piston internal combustion engine in the first rotation direction is assisted by the formation of the vacuum, characterized in that the rotation in the first rotation direction of the reciprocating piston internal combustion engine Control method for reversing or braking. The method of claim 3,
The third crank angle is selected so that a vacuum is formed in the first cylinder by closing the first outlet valve at the third crank angle in the reversing phase of the reciprocating piston internal combustion engine following the braking step, Characterized in that the restart of the reciprocating piston internal combustion engine in the second rotational direction, which is initiated in the second cylinder by the fuel supply, and which is opposite to the first rotational direction, is assisted by the vacuum formation in the first cylinder A control method for rapidly reversing or braking a rotation of a crankshaft of a piston internal combustion engine in a first rotational direction. 6. The method according to any one of claims 1 to 5,
Characterized in that the first outlet valve is closed at a fourth crank angle between the bottom dead center and the top dead point, preferably at a fourth crank angle which is reached after the supply of scavenged air into the cylinder has been terminated. A control method for rapidly reversing or braking a rotation of a crankshaft of a piston internal combustion engine in a first rotational direction. The method according to claim 6,
The fourth crank angle is selected so that excess pressure is formed in the first cylinder by closing of the first outlet valve at the fourth crank angle in the braking phase of the rotation of the reciprocating piston internal combustion engine, Characterized in that the rotation of the reciprocating piston internal combustion engine in the direction of rotation is assisted by the formation of the excess pressure so that the rotation in the first rotation direction of the reciprocating piston internal combustion engine can be quickly reversed or braked Lt; / RTI > The method according to claim 6,
The fourth crank angle is selected so that an excess pressure is formed in the first cylinder by the closing of the first outlet valve at the fourth crank angle in the reversing phase of the reciprocating piston internal combustion engine following the braking step, Characterized in that a restart of the reciprocating piston internal combustion engine in a second rotational direction, which is initiated in the second cylinder by the fuel supply, and which is opposite to the first rotational direction, is assisted by the formation of the excess pressure in the first cylinder Wherein the rotation of the reciprocating piston internal combustion engine in the first rotation direction of the crankshaft is reversed or braked. 9. The method according to any one of claims 1 to 8,
The restarting of the reciprocating piston internal combustion engine in the second rotational direction, which is initiated during the reversing phase, and which is opposite to the first rotational direction, is assisted by introducing a predetermined minimum amount of the starting air into the at least one cylinder of the reciprocating piston internal combustion engine Wherein the control means is configured to quickly reverse or brake the rotation in the first rotation direction of the crankshaft of the reciprocating piston internal combustion engine. 10. The method of claim 9,
The startup air is introduced into only a portion of the cylinders of the reciprocating piston internal combustion engine only to assist in restarting in the second rotational direction during the reversing phase, preferably into only one selected cylinder, Wherein the internal combustion engine is introduced into the reciprocating piston internal combustion engine in a first rotation direction of the crankshaft of the reciprocating piston internal combustion engine. 9. The method according to any one of claims 1 to 8,
Wherein the restarting of the reciprocating piston internal combustion engine in the second rotational direction, which is initiated during the reversing phase, and in the second rotational direction opposite to the first rotational direction, takes place without the use of the starting air. For quickly reversing or braking the rotation of the motor. 12. The method according to any one of claims 1 to 11,
Characterized in that the reciprocating piston internal combustion engine is a drive unit of the ship. A control method for quickly reversing or braking a rotation in a first rotation direction of a crankshaft of a reciprocating piston internal combustion engine.