Abstract:
This paper presents reliability, availability, and maintainability (RAM) analysis framework for evaluating
the performance of a circulation system of water (WCS) used in a coal-fired power plant (CFPP).
The performance of WCS is evaluated using a reliability block diagram (RBD), fault tree analysis (FTA),
and Markov birth–death probabilistic approach. In this work, the system under study consists of five
subsystems connected in series and parallel configuration namely condensate extraction pump (CEP),
low-pressure feed water heater (LPH), deaerator (DR), boiler feed pump (BFP), high-pressure feed water
heater (HPH). The reliability block diagram (RBD) and fault tree approach (FTA) have been employed
for the performance evaluation of WCS. The Markov probabilistic approach based simulation model is
developed. The transition diagram of the proposed model represented several states with full working
capacity, reduced capacity, and failed state. The ranking of critical equipment is decided on the basis of
criticality level of equipment. The study results revealed that the boiler feed pump affects the system
availability at most, while the failure of deaerator affects it least. The availability of the system is
optimized using the particle swarm optimization method. The optimized availability parameter (TBF,
TTR) based modified maintenance strategy is recommended to enhance the availability of the plant
system. The optimized failure rate and repair rate parameters of the subsystem are used to suggest
a suitable maintenance strategy for the water circulation system of the thermal power plant. The
proposed RAM framework helps the decision-makers to plan the maintenance activity as per the
criticality level of subsystems and allocate the resources accordingly.
