ISSN: 2319-8753 International Journal of Innovative Research in Science, Engineering and Technology (An ISO 3297: 2007 Certified Organization) Vol. 3, Issue 7, July 2014 Copyright to IJIRSET www.ijirset.com 14915 Reliability Investigation of Steam Turbine Used In Thermal Power Plant D. N. Dewangan 1 , Manoj Kumar Jha 2 , Y. P. Banjare 3 1 Department of Mechanical Engineering., Ph.D. Scholar, Dr. C.V. Raman University, Bilaspur, India. 2 Department of Applied Mathematics, Rungta Engineering. College, Raipur, India 3 Department of Mechanical Engineering., Govt. Engineering College, Jagdalpur, India ABSTRACT: The fault mode of steam-induced vibration, unbalance of rotating elements, misalignment of turbine shaft, rotor malfunction, oil film instability of bearing etc. are accountable for unreliable and uncertain failure of power plant. Experience of operators, maintenance policy execution of maintenance team and using standards codes of good practices by designers and manufacturers are reducing the potential failure modes of the system. The work investigate the reliability of steam turbines installed in a thermal power plant. Reliability estimation is based on a last five year historical failure database of two turbines of 500 MW, both are installed and commissioned at the same time. The method of reliability evaluation is based on concepts of system reliability, such as functional tree development, application of failure mode and effects analysis (FMEA) to categorize critical components based on a historical failure database to improve the system reliability. It is necessary to improve the reliability indices of the power plane by taking some measures such as well planned and routine maintenance of equipments as well as training and retraining of technical human resources of the major equipment. KEY WORDS: Reliability, Availability MTBF, MTTF, RCM, FMEA. I. INTRODUCTION Steam turbine generator set is a key device of the power plant. For competent power plant, cost-effective production and long run performance, it is essential to maintain the power plant should run failure free. Reliability analysis have gradually recognized as standard tools for the designing, scheduling of operation and maintenance of any system. The reliability of power plant is related to the possibility of giving electricity efficiently and more economical with a reasonable quality assurance of continuity [Wang et al., 2002]. A modern power plant system can be divided into generation, transmission and distribution functional area. The system can be considered independently or in combinations of all three functional areas. This work is limited to the evaluation of the generation reliability. The main aim is to development a method to improve the reliability of the steam turbine power plant. In this respect, Reliability centered maintenance concepts are utilized as a guideline for ranking the maintenance policy priorities of the critical components of steam turbine. The reliability of the system can be designated through the deterministically approach and/or probabilistic approach. Souza et al. (2012) deal with the probabilistic aspect of operational performance of power plant. In the work, deterministic approach of reliability analysis of the system is used to deals with understanding how and why a system is unsuccessful, and how it can be planned to avoid such failure from happening or re-happening. This includes analysis such as review of historical field failure reports, understanding scientific theory behind the failure, the role and degree of maintenance policies. Wang and Billinton (2003) reported that the role of a power plant is to provide electricity, resourcefully and with a reasonable guarantee of continuity and quality to its consumers. A modern power plant is very huge, multifaceted and highly integrated. Gupta and Tewari (2009a, and 2009b), Lakhoua, (2009) suggested that electric power plant can be divided into suitably subsystems or functional areas such as generation, transmission and distribution. Reliability studies may be carried out separately or in combinations of all three functional areas. This work is limited to the estimation of the generation reliability.