Development of Risk Based Maintenance Strategy for Gas Turbine Power System

The unexpected failures, the down time associated with such failures, the loss of production and, the higher maintenance costs are major problems in any power plant. Riskbased maintenance (RBM) approach helps in designing an alternative strategy to minimize the risk resulting from breakdowns or failures. The RBM methodology is comprised of four modules: viz identification of the scope, risk assessment, risk evaluation, and maintenance planning. Using this methodology, one is able to estimate risk caused by the unexpected failure as a function of the failure probability and the consequences of failure. Critical equipment can be identified based on pre-selected acceptable level of risk. Maintenance of equipment is prioritized based on the risk, which helps in reducing the overall risk of the plant. The case study of a power-generating unit in the Rukhia gas turbine power plant system is used to illustrate the methodology. Results indicate that the methodology is successful in identifying the critical equipment and in reducing the risk of failure of the equipment. Risk reduction is achieved through the adoption of a maintenance plan which not only increases the reliability of the equipment but also reduces the cost of maintenance including the cost of failure.