Maintenance class‐based cost‐effective preventive maintenance scheduling of coal‐fired power plants

This paper presents a new strategy for reliability‐based Preventive Inspection and Maintenance (PIM) scheduling of coal‐fired power plants considering maintenance costs. Preventive Inspection and Maintenance Interval (PIMI) for any series or parallel subsystem is optimised at the reliability level where total (preventive and corrective) life cycle maintenance cost is the minimum. PIM of any series subsystem in a continuous operating power plant is difficult since off‐working period is unavailable. Therefore a time management strategy followed by maintenance class formation is introduced for their PIM according to the estimated PIMIs. Here corrective maintenance of any failed subsystem along with PIM of the remaining subsystems in the same maintenance class is suggested. The case studies reveal that the optimum PIMIs of the subsystems vary from 75.8% to 93.2% reliability level. The proposed maintenance strategy is very simple, easy to implement, improves availability and reduces the maintenance costs.