Answer EKM Question 31
Q31.
Sketch and describe an overview Of the electronic controlled
camshaft-less engine with respect to the following operations:
(b) The pumps are of variable delivery type to maintain the rail pressure around 700-800 bar, based on the based on ZA40 fuel pump, controlled by an electrically driven shaft linked to the engine computer module.
(c) The engine computer control system known as the 'Wartsila Engine Control System (WECS)controls the delivery from the common rail to the individual cylinders via the volumetric Injection control system.
(d) The control system uses finely filtered engine LO pressurized by electric pumps to 200 bar, which offers the pressure to operate the control elements.
(e) When the Rail Valves are energized for injection by the control module, oil from the Control Rail opens the Injection Control Valves.
(f) The fuel injectors are pressurized and fuel oil pressure behind the Fuel Quantity Piston maintains this pressure at the injectors. As the Piston moves to the left a feedback signal is sent to the Cylinder Control Module.
(g) At low engine load the control system cuts out one of the three injection valves per cylinder. At very low load two of the three injection valves are cut out.
(b) In the exhaust valve actuator, fine-filtered servo oil acts on the underside of a free-moving actuator piston, with normal system oil above the actuator piston for valve actuation.
(c) The adjacent hydraulic control slide is precisely activated by a Sulzer rail valve and controls the flow of servo oil to the actuator piston so that the exhaust valve opens and closes at precisely the correct time with appropriate damping. Th exhaust valve actuator employs the same Sulzer rail valves as are used for the ICU.
(d) The exhaust valve drive on top of the valve spindle is equipped with two analogue position sensors to provide a feedback on valve operation to the WECS.
(e) The electronically-controlled actuating unit for each cylinder gives full flexibility for exhaust valve opening and closing patterns. At the same time, the actuating unit provides a clear separation of the clean servo oil and the normal system oil. Thus the exhaust valve hydraulics can be serviced without disturbing the clean servo oil circuit.
C. Cylinder lubrication system:
2. Lubricators, up to eight in a single row around the cylinder liner.
3. Filter and measuring system
4. Servo oil supply unit (on RTA engines) or pressure reducing unit (on RT-flex engines)
5. Control system
6. Crank angle sensors, two of which one is redundant
A pulse lubrication system is an electronically controlled cylinder oil lubrication system for Wartsila engines, wherein metered quantity of cylinder oll is injected in to the liner, depending on the engine load. This ensures that accurate amount of cylinder oil is delivered inside the liner at the correct set-time for that particular engine load.
Construction and Working of Pulse Lubrication System
(a) There are normally eight quills attached to the cylinder liner in a single row, which gets the oil supply from the electronically controlled dosage pump.
(b) The oil is supplied to the dosage pump from daily tank via One filter of 40 microns
(c) The quills consist of a duct passage to store metered quantity of oil. The area of this duct passage and the quantity of oil can be altered by changing the position of the central piston.
(d) There are crank angle sensors attached to the engine which give signals to the control unit in order to inject oil at the correct position of piston movement.
(e) 200 bar high pressure servo oil reduced to SO bars, are supplied to the lubricator unit, which pressurizes the centre piston in the quills. This injects oil inside the liner at adequate pressure for even distribution.
(f) Engine Control System which is the master controller.of the Pulse lubrication 'system controls the solenoid valve opening and the oil injection.
(g) Each unit is provided with 8 lubricating quills, 2 piping systems of Cylinder oil and servo oil, and A 4/2 solenoid valve to servo oil flow.
(h) After receiving signal from the crank angle sensor, at the correct position i.e. between the pack of piston rings, control system allows the solenoid valve to open and pass the servo oil. This,in turn presses the central piston and delivers the oil stored in the duct passage of the quills.
(i) As soon as the injection is over, there is a small orifice which fills the duct passage again with the cylinder oil as the central piston moves backward. This ensures that the oil is always present in the chamber in metered quantity as decided by the WECS after calculating load and sulphur content of the fuel.
a. Fuel Injection system.
b. Exhaust valve actuator system.
c. Cylinder lubrication system.
Answer: A. Fuel Injection system.Sulzer's RT Flex system is explained:
(a)
Sulzer methods us a pressurized fuel rail using a set of jerk type
pumps driven by a three-lobe cam which is connected to the crankshaft
via gear trains.
(b) The pumps are of variable delivery type to maintain the rail pressure around 700-800 bar, based on the based on ZA40 fuel pump, controlled by an electrically driven shaft linked to the engine computer module.
(c) The engine computer control system known as the 'Wartsila Engine Control System (WECS)controls the delivery from the common rail to the individual cylinders via the volumetric Injection control system.
(d) The control system uses finely filtered engine LO pressurized by electric pumps to 200 bar, which offers the pressure to operate the control elements.
(e) When the Rail Valves are energized for injection by the control module, oil from the Control Rail opens the Injection Control Valves.
(f) The fuel injectors are pressurized and fuel oil pressure behind the Fuel Quantity Piston maintains this pressure at the injectors. As the Piston moves to the left a feedback signal is sent to the Cylinder Control Module.
(g) At low engine load the control system cuts out one of the three injection valves per cylinder. At very low load two of the three injection valves are cut out.
B. Exhaust valve actuator system.
(a)
The actuating energy for operating the exhaust valve now comes from the
servo oil rail. There is one exhaust valve actuator (also known as the
partition device) for each cylinder.
(b) In the exhaust valve actuator, fine-filtered servo oil acts on the underside of a free-moving actuator piston, with normal system oil above the actuator piston for valve actuation.
(c) The adjacent hydraulic control slide is precisely activated by a Sulzer rail valve and controls the flow of servo oil to the actuator piston so that the exhaust valve opens and closes at precisely the correct time with appropriate damping. Th exhaust valve actuator employs the same Sulzer rail valves as are used for the ICU.
(d) The exhaust valve drive on top of the valve spindle is equipped with two analogue position sensors to provide a feedback on valve operation to the WECS.
(e) The electronically-controlled actuating unit for each cylinder gives full flexibility for exhaust valve opening and closing patterns. At the same time, the actuating unit provides a clear separation of the clean servo oil and the normal system oil. Thus the exhaust valve hydraulics can be serviced without disturbing the clean servo oil circuit.
C. Cylinder lubrication system:
The main components of the Wartsila Pulse Lubricating System are:
1. Pulse lubricating module, consisting of a dosage pump with electronically-controlled timing.
2. Lubricators, up to eight in a single row around the cylinder liner.
3. Filter and measuring system
4. Servo oil supply unit (on RTA engines) or pressure reducing unit (on RT-flex engines)
5. Control system
6. Crank angle sensors, two of which one is redundant
A pulse lubrication system is an electronically controlled cylinder oil lubrication system for Wartsila engines, wherein metered quantity of cylinder oll is injected in to the liner, depending on the engine load. This ensures that accurate amount of cylinder oil is delivered inside the liner at the correct set-time for that particular engine load.
Construction and Working of Pulse Lubrication System
(a) There are normally eight quills attached to the cylinder liner in a single row, which gets the oil supply from the electronically controlled dosage pump.
(b) The oil is supplied to the dosage pump from daily tank via One filter of 40 microns
(c) The quills consist of a duct passage to store metered quantity of oil. The area of this duct passage and the quantity of oil can be altered by changing the position of the central piston.
(d) There are crank angle sensors attached to the engine which give signals to the control unit in order to inject oil at the correct position of piston movement.
(e) 200 bar high pressure servo oil reduced to SO bars, are supplied to the lubricator unit, which pressurizes the centre piston in the quills. This injects oil inside the liner at adequate pressure for even distribution.
(f) Engine Control System which is the master controller.of the Pulse lubrication 'system controls the solenoid valve opening and the oil injection.
(g) Each unit is provided with 8 lubricating quills, 2 piping systems of Cylinder oil and servo oil, and A 4/2 solenoid valve to servo oil flow.
(h) After receiving signal from the crank angle sensor, at the correct position i.e. between the pack of piston rings, control system allows the solenoid valve to open and pass the servo oil. This,in turn presses the central piston and delivers the oil stored in the duct passage of the quills.
(i) As soon as the injection is over, there is a small orifice which fills the duct passage again with the cylinder oil as the central piston moves backward. This ensures that the oil is always present in the chamber in metered quantity as decided by the WECS after calculating load and sulphur content of the fuel.
Comments
Post a Comment