**2.1.2 Part-task simulators**

A part-task simulator is focused only on specific plant systems. These systems are represented with features of a full-scope simulator, in this way, detailed mathematical modelling of the referenced plant systems is included and just a part of the actual control room is duplicated with all key instrumentation, controls and alarm signals. The systems not included in the HMI are simulated with a reduced scope or no simulated and considered as always "on service", just to satisfy the interactions of the main systems. For instance, Figure 4 shows a part-task simulator to train operators in turning and acceleration of the steam turbine (Burgos, 1993). This simulator includes the portion of the control board corresponding to the steam valves (throttling, governing, stop and intercept) and the related instrumentation and control.

Fig. 4. Part task simulator

The systems connected to the steam turbine (including the thermal model for rotor and casings), lubrication oil, control oil and required controls are simulated in a full-scope context, but other systems like main steam, feed water and main condenser are simulated with a reduced scope. Therefore these simulators are beneficial to improve the knowledge and provide training in particular areas of the power plant. Tavira-Mondragón et al. (2006) describes a part-task simulator for five subsystems of a fossil fuel power plant with a HMI based on interactive process diagrams. The systems considered are: electric network, auxiliary services, boiler pressurization, turning turbine and power increasing from minimum up to nominal power. This simulator is portable to be transported to the power plants.

A different approach for a simulator is the proposed by Pevneva et al. (2007), these authors present a unified training simulator for the personnel of the boiler-turbine and chemical departments with the purpose of perfecting interaction skills between these areas.
