RAM investigation of coal-fired thermal power plants: A case study

S Chattopadhyay,G K Bose,D Bose,D D Adhikary,S Mitra

doi:10.5267/j.ijiec.2011.12.003

S Chattopadhyay, G K Bose + Show 3 more

Open Access

https://doi.org/10.5267/j.ijiec.2011.12.003

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Abstract

: Received 28 October 2011 Accepted December, 5 2011 Available online 8 December 2011 Continuous generation of electricity of a power plant depends on the higher availability of its components/equipments. Higher availability of the components/equipments is inherently associated with their higher reliability and maintainability. This paper investigates the reliability, availability and maintainability (RAM) characteristics of a 210 MW coal-fired thermal power plant (Unit-2) from a thermal power station in eastern region of India. Critical mechanical subsystems with respect to failure frequency, reliability and maintainability are identified for taking necessary measures for enhancing availability of the power plant and the results are compared with Unit-1 of the same Power Station. Reliability-based preventive maintenance intervals (PMIs) at various reliability levels of the subsystems are estimated also for performing their preventive maintenance (PM). The present paper highlights that in the Unit-2, Economizer (ECO) & Furnace Wall Tube (FWT) exhibits lower reliability as compared to the other subsystems and Economizer (ECO) & Baffle Wall Tube (BWT) demands more improvement in maintainability. Further, it has been observed that FSH followed Decreasing Failure Rate (DFR) and Economizer (ECO) is the most critical subsystem for both the plants. RAM analysis is very much effective in finding critical subsystems and deciding their preventive maintenance program for improving availability of the power plant as well as the power supply.

Highlights

With the rapid growth in domestic and commercial market in Indian electricity, consumption is increasing with leaps and bounce
Baffle Wall Tube (BWT) is best fitted to lognormal distribution
Final Superheater (FSH) follows power law process Non-Homogeneous Poisson Process (NHPP) model with shape parameter β

Summary

Introduction

With the rapid growth in domestic and commercial market in Indian electricity, consumption is increasing with leaps and bounce. Kaushik and Singh (1994) presented reliability analysis of the feed water system in a thermal power plant They calculated reliability and availability function (Av) and mean time to failure (MTTF) of this system, followed by analysis of the results. Adhikary et al (2010) analyzed the reliability, maintainability and availability characteristics of a coal-fired power plant of 210 MW (Unit-1) from a power station, in eastern region of India. The respective failure and repair data of the power plant due to the failure of mechanical components/equipments are sorted into 10 subsystems for easy estimation of reliability, maintainability and availability. The subsystems are Economizer (ECO), Furnace Wall Tubes (FWT), Baffle Wall Tubes (BWT), Primary Superheater (PSH), Platen Superheater (PLSH), Final Superheater (FSH), Turbine (TUR), Primary Reheater (PRH), Pendent or Final Reheater (FRH) and Condenser (CON) These subsystems are in series from the reliability and maintainability point of view. Adhikary et al / International Journal of Industrial Engineering Computations 3 (2012)

Data collection

Trend Test

Serial Correlation Test

Goodness-of-fit Test for iid data and their parameters estimation

Goodness–of-fit Test for non-idd data and the parameters estimation

Reliability analysis

Availability analysis

10. Maintainability analysis

Findings

11. Conclusions