Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
  • F01L13/02—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for reversing
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
  • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
  • F02D13/028—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation for two-stroke engines
  • F02D13/0284—Variable control of exhaust valves only
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2250/00—Engine control related to specific problems or objectives
  • F02D2250/06—Reverse rotation of engine

Definitions

• the invention relates to a control method for quickly reversing or braking a rotation in a first direction of rotation of a crankshaft of a reciprocating internal combustion engine, in particular slow-running longitudinally flushed two-stroke large diesel engine according to the preamble of independent claim 1.
• the construction of the drive is much simpler compared to a drive in which between the propeller and engine nor a transmission is provided.
• the disadvantage of such a construction without gear and clutch is, however, that the propeller is always, that is in any operating condition rotatably connected to the engine and at least in the operating condition of the engine, that is, as long as it has not come to a halt completely, not from this can be separated. That is, in an operating condition in which the engine is stopped to decelerate the ship, which in practice means essentially that the fuel supply to the engine is interrupted, the ship does not immediately stop in place, but is due to his enormous Continue inertia initially and gradually lose speed gradually.
• the propeller is now no longer driven by the engine; But now, driven by the continuing relative speed between propeller and water by driving through the water.
• the propeller is rotatably connected to the engine and this can not be separated from the engine, in such an operating state, the engine is now driven by the propeller. That is, in a considerable period of time after stopping the fuel supply to the engine, this will still continue to turn in the original direction because it is now driven by the propeller.
• An acceleration of the deceleration of the ship or a reversal of the direction of travel of the ship can only be achieved by restarting the engine in the reverse direction.
• This can only be achieved in most known marine engines, and in particular in the giant two-stroke, longitudinally-scavenged diesel engines, by providing, at an appropriate time, i. at a suitable crank angle compressed air, also known in the trade as starting air, is pressed under a sufficiently high pressure into the cylinder liner, so that the engine is restarted by the starting air acting on the pistons in the desired reverse direction of rotation.
• the propeller via the crankshaft to the pistons in the cylinder liners of the engine exerts such that the engine rotates in spite of inhibited fuel supply further in the original direction, the engine can then be restarted in the opposite direction at the earliest if the maximum available pressure of the starting air is sufficient to compensate for the forces acting on the piston by the propeller, that the engine can be offset by the starting air in a sufficiently fast rotation in the opposite direction, so that when reactivating the fuel supply, the engine can finally restart independently in the reverse direction.
• the marine propeller connected to the engine will also be propelled in the opposite direction by the engine, causing the vessel to decelerate progressively until the ship finally stops or, if desired, the vessel can record travel in the opposite direction.
• the object of the invention is therefore to provide a method by which a motor, in particular a slow-running longitudinally flushed two-stroke large diesel engine can be redirected more efficiently and faster in an opposite direction of rotation, the problems described in the prior art are largely avoided, especially from The fatal safety problems known from the state of the art can be circumvented and the reversing of the motor can be carried out more economically and energy-saving.
• the invention thus relates to a control method for quickly reversing or braking a rotation in a first rotational direction of a crankshaft of a reciprocating internal combustion engine, in particular slow-running longitudinally flushed two-stroke large diesel engine, comprising a cylinder in which a piston between a top dead center corresponding to a crank angle of 180 ° and a Bottom dead center according to a crank angle of 0 ° or 360 ° is arranged to move back and forth, as well as with an outlet valve, which is hydraulically actuated by means of a standing under a predetermined opening pressure hydraulic medium, preferably hydraulic oil via a valve hydraulics.
• a fuel supply to the reciprocating internal combustion engine is interrupted in a deceleration phase and the hydraulic medium is supplied at a first maximum opening pressure of a valve hydraulics of a first exhaust valve of a first cylinder at a first crank angle in the region of the top dead center of the first cylinder associated with the first cylinder, so that the first exhaust valve, at the earliest when passing through the first piston through its top dead center position, is automatically opened by the valve hydraulics at a second crank angle.
• a method for the first time, with which a motor, in particular a slow-running longitudinally flushed two-stroke large diesel engine can be reversed more efficiently and faster in an opposite direction of rotation, while at the same time valuable starting air can be saved.
• a restart in the opposite direction of rotation can be initiated even without starting air, for example by utilizing the braking energy transmitted to the engine by the propeller, which of course is not only an economic improvement that should not be underestimated , But especially if the inventive method for reversing or deceleration an engine of a ship is used, also represents an enormous progress from a safety point of view.
• the reciprocating internal combustion engine is a slow-running longitudinally-flushed two-stroke large diesel engine of a ship, such as a container ship with a huge engine, for example, up to twelve cylinders or more and has an output of up to 10,000KW per cylinder, or even greater benefits.
• a piston reciprocates between top dead center and bottom dead center in a cylinder liner and drives via a crankshaft which is operatively connected to the piston and a propeller Ship propeller.
• An outlet valve on a cylinder cover of the cylinder liner is hydraulically actuated via valve hydraulics by means of a programmable control device, which may in practice comprise a hydraulic device and an electronic device.
• a crank angle in which the exhaust valve is actuated, can be predetermined in principle as desired by the programmable control device.
• crank angle of 0 ° or 360 ° is identified with the bottom dead center UT and a crank angle of 180 ° with the top dead center OT.
• the piston Starting from bottom dead center, corresponding to a crank angle of 0 °, the piston initially moves in the operating state in the direction of TDC, corresponding to a crank angle of 180 °.
• the scavenging slots in the lower region of the cylinder liner are released in the normal operating state and the outlet valve 5 is opened.
• the scavenging slots are released from the piston fresh air is supplied to the combustion chamber of the cylinder liner through the scavenging slots and simultaneously combustion residues are flushed out of the combustion chamber by the movement of the piston in the direction of top dead center through the exhaust valve.
• the exhaust valve is closed at a predetermined crank angle by means of the control device as the crank angle increases.
• fuel is supplied through an injection valve to the combustion chamber of the engine, which is formed from the upper cylinder region, the cylinder cover located above and the piston crown, which ignites in the air heated by the compression in the region of top dead center, subsequently burned and by this energy release leads to pressure increase in the combustion chamber of the engine.
• the piston After passing through the top dead center, the piston moves back toward the bottom dead center corresponding to a crank angle of 360 °.
• the outlet valve is then opened again at a crank angle which is significantly greater than 180 °, and a new working stroke of the cylinder is initiated.
• the reciprocating internal combustion engine was also in the already known method from the normal operating condition as follows Braking or reversing put into another operating state.
• a first step it is known to interrupt the supply of fuel into the cylinder liner of the reciprocating internal combustion engine.
• the speed of the engine initially drops, resulting in a first moderate slowdown of the ship. If no further measures are taken, the speed of the ship is reduced substantially due to the friction of the ship in the water. This friction is generally comparatively low, so that the speed of the ship is reduced only very slowly.
• the propeller which is no longer driven by the Hubkolbenbrennmaschine after interrupted fuel supply, now works, driven by the remaining kinetic energy of the ship as a turbine and now drives the engine, with which it is rotatably connected via the crankshaft.
• the second crank angle is in a range between the top dead center and the bottom dead center of the first piston at a value between 180 ° and 360 °, preferably at a value between 180 ° and 225 °, or between 180 ° and 200 °, more preferably at a second crank angle, which is between 180 ° and 190 ° after top dead center of the first piston.
• the first exhaust valve is closed again at a third crank angle in the range between the second crank angle and the bottom dead center of the first piston to generate a predetermined negative pressure in the first cylinder.
• the third crank angle is selected so that by closing the first exhaust valve at Third crank angle, a negative pressure in the first cylinder is constructed such that a restart in a second cylinder by a fuel supply restart of the reciprocating internal combustion engine in a direction opposite to the first direction of rotation second rotational direction, supported by the structure of the negative pressure in the first cylinder.
• a further additional or alternative measure of an inventive method is that the first exhaust valve is closed at a fourth crank angle between the bottom dead center and top dead center, preferably at a fourth crank angle, which is reached after stopping the supply of purging air into the cylinder ,
• the fourth crank angle is selected so that the closure of the first exhaust valve at the fourth crank angle, an overpressure in the first cylinder is constructed, braking the rotation of the reciprocating internal combustion engine in the first direction of rotation by the structure be supported by the overpressure.
• the fourth crank angle is selected so that by closing the first exhaust valve at the fourth crank angle, an overpressure in the first cylinder is constructed such that the building up in the first cylinder pressure with one in a second Cylinder by a fuel supply initiated restart of the reciprocating internal combustion engine is suitably coordinated in a direction opposite to the first direction of rotation second direction of rotation, can be effectively supported by the structure of the pressure in the first cylinder restart in the opposite direction.
• the opposite to the first rotational direction of the second rotational direction are additionally supported by introducing a predetermined minimum amount of starting air in at least one cylinder of the reciprocating internal combustion engine, whereby the reversing in the second direction of rotation or braking from the first direction of rotation can be additionally accelerated.
• the starting air is sequentially introduced only in a part of the cylinder of the reciprocating internal combustion engine, preferably even only in a single selected cylinder and is not introduced into any other cylinder.
• the reciprocating internal combustion engine has a plurality of cylinders, which are in a conventional manner at least partially each at different crank angles, so that the measures mentioned here for accelerating the deceleration or reversal of the engine can be taken simultaneously, so that there is a cumulative effect of the different measures.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Valve Device For Special Equipments (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

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• 2015
  • 2015-09-08 DK DK15184261.4T patent/DK3015663T3/en active
  • 2015-09-08 EP EP15184261.4A patent/EP3015663B1/de active Active
  • 2015-10-13 CN CN201510657252.6A patent/CN105569760B/zh active Active
  • 2015-10-16 KR KR1020150145002A patent/KR102390243B1/ko active IP Right Grant
  • 2015-10-16 JP JP2015204151A patent/JP6807150B2/ja active Active

Non-Patent Citations (1)

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