Keywords: gas expansion turbines, maintenance intervals, risk-based maintenance, RBM, steel plants, gas turbines, unexpected failure, breakdowns, risk assessment, risk acceptance criterion, maintenance planning, maintenance scheduling
Risk-based maintenance of gas expansion turbines in steel plant
Unexpected failures, loss of production, higher maintenance costs and down time associated with the failures of equipment are major problems in any plant. Adopting the risk-based maintenance (RBM) approach helps in designing an alternative strategy to minimise the loss resulting from these breakdowns or failures. The methodology consists of four modules: system definition, risk assessment, risk acceptance criterion and maintenance planning. In this study, the RBM approach was adopted for a gas expansion turbine of a steel plant. The resultant risk of the system was found to be unacceptable. Amongst the eight units (subsystems) comprising the system, only two units namely, the governing system and rotor blades, are responsible for such a high risk situation. A risk based maintenance schedule (maintenance intervals) was proposed for the components of the two subsystems. It is observed that the new RBM scheme, if used properly, would bring down the unacceptable level of risk to the desired level.