Sulzer RT-flex. Electronic control\r\n
All functions in the Sulzer RT-flex system are controlled and monitored through the Wartsila Engine Control System (WECS). This is a modular electronic system with separate microprocessor control units for each cylinder, and overall control and supervision by duplicated microprocessor control units. The latter provide the usual interface for the electronic governor and the shipboard remote control and alarm systems. The microprocessor control units, or electronic control units, are mounted directly on the engine, either on the front of the rail unit or adjacent to it.\r\n
An essential input signal for WECS is the engine crank angle. This is measured very accurately by two sensors driven from a stub shaft on the free end of the crankshaft. The two sensors are driven by toothed belts so that axial and radial movements of the crankshaft are not passed to the sensors. The sensors are able to give the absolute crank angle position immediately that electrical power is applied.
Fig 9. Electronic control units beneath the front of the rail unit of a Sulzer RT-flex96C engine
At present RT-flex engines are being equipped with the WECS-9500 control system. However, this will be superseded in 2005 by the WECS-9520 control system. The new system provides simpler communication with the ship automation system and easier wiring for the shipbuilder. Only one electronic module is used throughout the new system, and there are fever equipment boxes which are also of simple, standard design. The functionality of WECS-9520 is the same as that of the WECS 9500 system.
Sulzer RTA and RT-flex engines have standardised interfaces (DENIS) for remote control and safety systems. The remote control and safety systems are supplied to the ship by a variety of approved manufacturers and DENIS (Diesel Engine Interface Specification) defines the interface between the engine-mounted equipment and the shipboard remote control and safety system.
With RT-flex engines, the remote control sends engine manoeuvring commands to the WECS. The remote control processes sped signals from the engine order telegraph according to a defined engine load program and fuelling limitations, and generates a fuel reference signal for the WECS according to DENIS.
The safety system function in RT-flex engines is basically the same as in conventional RTA engines, except that it has additional inputs for WECS slowdown and WECS shutdown signals, and some outputs to the WECS system.