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Top1. Introduction
A most conventional source of electric energy is thermal power plant. The electric power is produced by two types of thermal power plant: coal thermal power plant and steam turbine power plant. In India, sixty-five percent electricity is generated by thermal power station. In this research work, the authors have studied the steam turbine thermal power plant which consists some main components such as three steam turbines, boiler, condenser and generator. Boiler helps to boil the water to make the steam and sent to steam turbines. Steam turbines covert the steam power into mechanical energy which drives the generator and exhaust the steam which is condensed by condenser. Thus, generator produces electric power.
The thermal power plant is becoming quite complex with a huge investment being incurred on process automation to enhance the reliability of system. The performance of thermal power plant is mainly defined by the reliability characteristics such as availability, reliability and mean time to failure of the plant. These reliability measures of thermal power plant are affected due to failure of their sub-system and some other failures like catastrophic failure. Failures and proper maintenance of such systems are significant issues that have progressive importance in the performance of thermal power plant and expected profit in it. High reliability is desirable to reduce the maintenance cost of the plant.
In context of earlier study on thermal power plant, Gupta and Tewari (2009) proposed a probabilistic model of flue gas and air system. They formulated the model with Markov birth-death process and analysed the system availability. Authors also discussed the maintenance priority for the sub-system contained in the flue gas and air system of the thermal power plant. Tewari et al. (2012) designed a probabilistic model with Markov process and formulated using Chapman-Kolmogorov equations. Authors discussed the performance of steam generating system in terms of availability including different failure and repair rates of the steam generating system in thermal power plant. Boiler in thermal power plant is an important component which plays a major role in the plant for generating electricity. Many authors (Arora & Kumar, 1997; Musyafa & Adiyagsa, 2012; Felea, Secui, Ciobanca, Goia, 2013) studied about the performance of boiler. Felea et al. (2013) analysed the operational reliability of boiler from Oradea Combined Heat and Power (CHP) plant. They used the database fom 2000 to 2011 of CHP plant. While Musyafa and Adiyagsa (2012) discussed the performance of boiler on the basis of pulverize, contained in boiler. Kumar and Ram (2013) analyzed the reliability measures of a coal handling unit for thermal power plant with the consideration of only equipment failure. They also found the sensitivity of reliability measures of coal handling unit.
Reliability has a wide history in the world of research. Many researchers have done a lot of work in the field of reliability. Simons and Chu (2000) addressed about thermo-electric cooling system and its application. They described the term power dissipation and chip temperature reduction to improve thermo-electric cooling system. Wikstrom, Terens, and Kobi (2000) explained the terms such as reliability, availability and maintainability of large drives systems. They focused only those systems which drive with high electric power and not compared their results with steam or gas turbine drive systems. Cai, Wu, and Zhou (2005) discussed the problem of optimal dynamically policies for a machine, subjected to the preemptive repeat breakdown system. The machine is processed for a set of n jobs. Ram, Singh, and Singh (2013) have also analyzed a standby system with waiting for repair strategy. A reliability engineer should be aware about the importance of each reliability measure of the system and its fields. Singh, Ram, and Rawal (2013) introduced a method for analyzing the cost of a general engineering complex system and founded the reliability measures. They also studied how to achieve the maximum profit.