A Study on the Hybrid Reliability Centered Maintenance Methodology for Rotating Machinery in Power Plants

2021 ◽  
Vol 9 (1) ◽  
pp. 75-83
Author(s):  
Heesoo Kim ◽  
Youngjin Roh ◽  
Jungwook Son ◽  
Gangmin Lim ◽  
Seonhwa Kim
Keyword(s):  
Power Plants ◽  
Rotating Machinery ◽  
Reliability Centered Maintenance ◽  
Hybrid Reliability

scholarly journals Dynamic Hybrid Reliability Studies of a Decay Heat Removal System

2015 ◽  
Vol 22 (04) ◽  
pp. 1550020 ◽  
Author(s):  
Ranjan Kumar ◽  
Pavel Kudinov ◽  
Sevostian Bechta ◽  
Florence Curnier ◽  
Michel Marques
Keyword(s):  
Safety Assessment ◽  
Power Plants ◽  
Stochastic Systems ◽  
Heat Removal ◽  
Dynamic Interactions ◽  
Decay Heat ◽  
Mission Time ◽  
Hybrid Reliability ◽  
Dynamic Hybrid ◽  
Safety Systems

Some critical safety systems exhibit the characteristics of hybrid stochastic class whose performance depends on the dynamic interactions of deterministic variables of physical phenomena and probabilistic variables of system failures. However, conventional probabilistic safety assessment (PSA) method involves static event and linked fault tree analysis and does not capture the dynamic interactions of such hybrid stochastic systems. Additionally, the existing dynamic PSA methods do not consider any repair possibility of some failed components during safety assessment. To address these issues, this paper presents a dynamic hybrid reliability assessment scheme for performance studies of repairable nuclear safety systems during a mission time. This scheme combines the features of reliability block diagram (RBD) for system compositions and partial differential equations for system physics using a customized stochastic hybrid automata tool implemented on Python platform. A case study of decay heat removal (DHR) systems has been performed using the introduced scheme. The impacts of failure rates and repair rates on sodium temperature evolution over a mission time have been analyzed. The results provide useful safety insights in mission safety tests of DHR systems. In sum, this work advances the dynamic safety assessment approach for complex system designs including nuclear power plants.

scholarly journals Forced Outage Analysis of Brazilian Thermal Power Plants using the Kruskal-Wallis Test

2020 ◽  
Author(s):  
Leonardo dos Santos e Santos
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Distribution Fitting ◽  
Interconnected System ◽  
Electric Sector ◽  
Electricity System ◽  
Reliability Centered Maintenance ◽  
System Operator ◽  
Expansion Pattern

In this paper, the forced outage data from the Brazilian National Interconnected System (SIN) is provided and the statistics from the thermal power plants are computed. The SIN is characterized by a marked seasonality in electricity supply. In addition, the expansion pattern of the Brazilian electric sector shows signs of exhaustion, and the demand for flexible thermal power plants, based on availability, requires outage management as a reliability-centered maintenance (RCM) strategy. In this work, the non-parametric Kruskal-Wallis test and Dunn’s pairwise-comparisons were chosen for evaluating the mean forced outage duration (MFOD) and the forced outage factor (FOF) using the data from the national electricity system operator (ONS) with R Software. The distribution fitting was provided using Weibull++ software from Reliasoft. Based on the MFOD and unit failure rate data, the FOF for Brazilian thermal power plants is 3.33% with a 90% probability and 95% confidence level. Finally, Brazilian thermal power plants were benchmarked against North American power plants.

scholarly journals Forced Outage Analysis of Brazilian Thermal Power Plants using the Kruskal-Wallis Test

2020 ◽  
Author(s):  
Leonardo dos Santos e Santos
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Distribution Fitting ◽  
Interconnected System ◽  
Electric Sector ◽  
Electricity System ◽  
Reliability Centered Maintenance ◽  
System Operator ◽  
Expansion Pattern

In this paper, the forced outage data from the Brazilian National Interconnected System (SIN) is provided and the statistics from the thermal power plants are computed. The SIN is characterized by a marked seasonality in electricity supply. In addition, the expansion pattern of the Brazilian electric sector shows signs of exhaustion, and the demand for flexible thermal power plants, based on availability, requires outage management as a reliability-centered maintenance (RCM) strategy. In this work, the non-parametric Kruskal-Wallis test and Dunn’s pairwise-comparisons were chosen for evaluating the mean forced outage duration (MFOD) and the forced outage factor (FOF) using the data from the national electricity system operator (ONS) with R Software. The distribution fitting was provided using Weibull++ software from Reliasoft. Based on the MFOD and unit failure rate data, the FOF for Brazilian thermal power plants is 3.33% with a 90% probability and 95% confidence level. Finally, Brazilian thermal power plants were benchmarked against North American power plants.

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