The graph theoretical analysis and a graph’s characteristic polynomial are deployed as the basis for a system approach employed to develop a model for estimating the reliability index and evaluating the availability index for a coal‐fired generating power station. In this research, the coal‐fired generating station system is divided into six sub‐systems. Elementary to evaluating the reliability (estimate) of the said system is the consideration of all the sub‐systems and their interrelations. Approximate reliability attributes of the graph are used to model the approximate reliability of the coal‐fired generating station. Sub‐system reliability is represented by the nodes in the graph, and the links represent the reliability of interrelations of these sub‐systems. Computing a graph’s characteristic polynomial using three different methods, namely, the linearly independent cycles, the figure equation and the adjacent matrix, the approximate reliability of the system is determined. Three methods are used, for comparison purposes, as estimating reliability is always an imperfect endeavour. The methodology proposed in this study is illustrated step‐by‐step with the help of examples.
Part of the book: Recent Improvements of Power Plants Management and Technology
This chapter looks at cannibalization as a method (procedure) of improving reliability of engineering systems. Cannibalization gives one the opportunity to use resources in the most efficient way. In this chapter, we have explored strategies to reduce the adverse effects of cannibalization on maintenance costs and personnel morale. The strategies developed in this chapter, at least, can be used to determine (1) which types of cannibalizations are appropriate, (2) cannibalization reduction goals and (3) the actions to be taken to meet the cannibalization reduction goals. In this chapter, we also presented a combined analytical and simulation model of a two-line, three-line and k-line system when cannibalization is not allowed and when cannibalization is allowed (with and without short interruptions to the system). It is clear from the analytical and simulation results that cannibalization can substantially increase the reliability of the systems where it is allowed. The improvement factor of unreliability obviously exists in systems where cannibalization is allowed as compared to those in which cannibalization is not allowed. Moreover, the improvement factor is larger when we have two-stage cannibalization (short interruptions) than without them.
Part of the book: System Reliability