**2.1.3 Compact simulators**

96 Fossil Fuel and the Environment

The simulator also can reproduce abnormal or emergency situations due to a deficient operation of the trainee or due to a malfunction inserted by the instructor. In the last case, during the specification of the simulator must be defined a malfunctions group. These malfunctions are of two types: binary and analogue. The first group contains malfunctions like: pump trips, fail position of valves, etc. The analogue malfunctions have a degree of severity (usually normalized from 0 to 100%) and their severity can be selected by the instructor. Examples are tubes rupture of steam lines and fouling factor of heat exchangers.

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

Instructor Console

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

**2.1.2 Part-task simulators** 

instrumentation and control.

Fig. 4. Part task simulator

power plants.

Compact simulators are frequently generics, this means they reproduce the behaviour of a specific power plant, but the rated power and the HMI for the trainee no necessarily are the same of the actual plant. However, they include mathematical modelling of wide scope which allows simulating plant conditions from cold iron up to nominal power. In this way they are mainly utilized to train novice operators and field personnel. Fray and Divakaruni (1995) claim this kind of simulators can be parameterized with unit-specific design and operating data for power units of specific generation and inclusive it is possible to include the emulation of an exact replica of the plant control system. This type of modifications necessarily increment the initial cost of the simulator and such modifications must be done by very specialized personnel.

Currently, with the power of modern computers, a complete power plant simulator can be installed in a laptop and easily transported, the main problem is the use of the simulator by the trainee because its interface is reduced, in the best-case scenario to a equipment with three displays (Figure 5), and with the number of actions required to operate the simulated system, a suitable training can be a complex problem without a effective method to do it.

Fig. 5. Compact simulator
