RT-flex Control Elements - HMShmstc.or.kr/file/BBS1/30_RT-flex_Hyh-Pneu components.pdf · RT-flex...

© Wärtsilä Land & Sea Academy Chapter 30 30-Apr-09

RT-flex Control Elements

RT-flex Training

Function of the different Hydraulic- and Pneumatic

Components

Chapter 30


RT-flex Control Elements Overview

Injection ControlExhaust Valve Control

Servo oil pressure controlFuel pressure control

Control oil pumps control

Valve stroke measurementICU stroke measurement

Crank angle detection

Auxiliary Functions

Main FunctionsStarting Valve Control


RT-flex Control Elements Injection Control Unit (ICU)

The ICU controls the timing and volume of the injection.

Each ICU has 3 (or 2) “rail valves” to pre- control its own “injection control valve”. The injection control valves control the movement of the “fuel quantity piston”.


RT-flex Control Elements ICU

WECS-9520 controlServo (control) oil

supply 200 bar


RT-flex Control Elements ICU Cross-Section



Fuel rail

Servo rail

Rail valves

Injection control valves

Fuel quantity piston

Fuel quantity sensor

Fuel nozzles

(Size 4: Control rail)

© Wärtsilä Land & Sea Academy Page 9 Chapter 30 30-Apr-09

RT-flex Control Elements ICU, new leak drain (96C-B)

New piping layout separates leak drain from injection pipes and from ICU internals.

Inspection plug for visual check of leak.


RT-flex Control ElementsFuel overpressure regulating valve:

In case of the fuel pressure in intermediate accumulator pipe or fuel rail pipe rises to ~1’050 bar, the overpressure regulating valve releases fuel to the fuel return line. The opening pressure is pre-adjusted by valve manufacturer. Shims are used to give the right position to the knurled screw, means if the screw is fully screwed down to shims, 1’050 bar are set

for new building RT-flex84T-D and 96C-Bengines’ opening pressure is 950 barfor in-service RT-flex84T-D and 96C-Bsee Service Letter RT-flex-07/07

The min. opening pressure, means when knurled screw is screwed fully out, is around 500 bar (engine still operational).During normal operation, main bearing oil pressure keeps the valve closed. When the opening fuel pressure is reached, main bearing oil is released, pressure above piston drops and fuel is released.

Fuel Overpressure Regulating Valve


RT-flex Control Elements Shutdown Valve

Shutdown Solenoid valve

MB-oil supply

Oil filter

Lever for manual de- pressurising for mainte- nance work

Piston

Solenoid valve leak drainEngine shutdown function:

A shutdown is initiated by energizing the solenoid valve (energized from safety system, not WECS). In this way, main bearing oil pressure above piston is released, resulting in fuel pressure drop down engine stops


RT-flex Control Elements (exhaust) Valve Control Unit (VCU)


RT-flex Control Elements VCU


RT-flex Control Elements VCU (general working principle)

The valve control unit is pre-controlled by the rail valve. At a certain crank angle, it gets an „exhaust valve open“ impulse signal from WECS. Servo oil flows via rail valve to the lower side of the 3/2 way valve spindle and moves it up. Thus, servo oil flow to the VCU-cylinder is enabled. Via bores in the VCU-piston, oil flows into the lower side of the piston and moves it towards the upper end.

the exhaust valve opens

At another calculated angle, WECS-9520 transmits an „exhaust valve close“ signal to the rail valve. The 3/2 way valve spindle moves down, releasing the oil from the VCU-piston underside allowing the oil volume in the exhaust valve to return to the VCU. The servo oil underneath the VCU piston is drained to the servo oil return pipe.

the exhaust valve is closing

Due to certain control bores or chamfers, the VCU- piston has a progressive movement. Means, it starts to move fast and slows down, as it gets closer to the end stop. The losses of servo oil through the orifice on the exhaust valve side is compensated in the VCU with servo- or main bearing oil.

Rail valve

VCU piston

3/2 way valve spindle

Actuator pipe withmain bearing oil

The servo oil return pipe has a back pressure of ~2-3 bar, in order to dampen pressure peaks.



The servo oil supply from the servo oil rail is done via connecting element.

To compensate the intended oil loss through the constant orifice in the exhaust valve drive upper housing, there is a main bearing oil inlet via a non-return valve.

VCU cylinder

Main bearing oilsupply, (non returnvalve at inlet)

3/2 way valve

Connecting element

Servo oil return/outlet

To exhaust valve drive

Filter insert

Rail valve

Valid for flex 58T (MKI), 60C (MKI), 96C-B


RT-flex Control Elements VCURail Valve

3/2 way valve

VCU piston

Servo oil supply

To exhaust valve drive

Servo oil return

HP-hoses to/from ICU

The VCU sits directly on the servo rail.

In order to refill the intended oil loss through the constant orifice in the exhaust valve drive upper housing, there is an internal orifice to the upper part of the VCU/actuator pipe.

Valid for flex 50B, 58T (MKII), 60C (MKII), 68B, 84T-D



Servo rail

Rail valve Slide rod Piston

Position sensor

Spring air

Exhaust valve

*) internal from servo rail or external from lube oil

Oil supply *)


RT-flex Control Elements Automatic Filter

Servo oil and control oil is fine filtered before it enters the pumps and hydraulics. The automatic filter has cartridges of nominal 6 µm. There is an bypass filter of 36 µm mesh size.

The reason for filtering is to increase the lifetime and safety margin of all hydraulic components.

Control box with indications


RT-flex Control Elements Automatic Filter

The back flushing is automatically initiated by the control box either

A) standard: Time controlled (after 1 hour)

B) or: if the differential pressure across the filter becomes too high (0.35 bar)

The filter "sludge" goes back to the crankcase. It is filtered system oil which is clean enough for normal use.

In the filter control box the back flushing is initiated either by time or differential pressure. Flushing cycles are counted. Failure messages are generated if necessary (Over current, differential pressure high etc…)

Inside the box there are switches/buttons to switch from “Operation” to “Adjust”. For detailed information please consult filter maker’s manuals.


RT-flex Control Elements Air system

Air is used for:

Actuation of automatic start valve

Starting of engine

Spring air supply

(Oil mist detector)

Flushing of automatic filter for servo and control oil

(OMD)(SHD valve)


RT-flex Control Elements Air supply

From starting air bottles (30 bar)

From control air supply (7-9 bar)

To air springs To automatic main starting valve

through turning gear

(OMD)(SHD valve)


RT-flex Control Elements Control air supply unit


RT-flex Control Elements Air system (size 0)

Air is used for:

Actuation of automatic start valve

Starting of engine

Spring air supply

(Oil mist detector)

Flushing of automatic filter for servo and control oil


RT-flex Control Elements Air supply (size 0)

From control air supply (7-9 bar)

To air springs and automatic main starting valve through turning gear


RT-flex Control Elements Main starting valve


RT-flex Control Elements Starting air

RT-flex Control Elements - HMShmstc.or.kr/file/BBS1/30_RT-flex_Hyh-Pneu components.pdf · RT-flex...

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