Reliability and Economic Analysis of a Power Generating System Comprising One Gas and One Steam Turbine with Random Inspection

Reliability and economic analysis for a power generating system comprising one gas and one steam turbine has been done wherein the inspection for doing one of the three types of maintenance (Minor, Path or Major) is carried out randomly. Initially, both the units i.e., the gas turbine as well as the steam turbine are operating. On failure of the gas turbine, the system goes to down state, whereas on failure of the steam turbine, the system may be kept in upstate with only gas turbine working if the buyer of the power so generated is ready to pay higher amount or otherwise put to down state. System is analyzed by making use of semi-Markov processes and regenerative point technique. Expressions for the reliability of the system and various measures related to the economy have been obtained and then the expression for profit incurred to the system is also obtained. Study through graphs is made which lead to interesting conclusions. Cut-off points with respect to the revenue per unit up time in both the cases i.e., when the system works in combined cycle and when it works in single cycle have been obtained which help in deciding the minimum price of the electricity produced in such a way so as to get the positive profit.