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1

Reliability evaluation of electrochemical energy storage systems supplying the ship's main propulsion system

Szewczyk P., Łebkowski A.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 1

87--94

EN

The paper presents the structure of hybrid and electric modern ship propulsion systems. Types and configuration of electrochemical cells for selected electric energy storage facilities on the ship were presented. The method and results of reliability analyses, such as failure mode effect analysis (FMEA), reliability block diagram (RBD) and fault tree analysis (FTA), used to estimate the probability of failure of the energy storage systems supplying the ship's main propulsion, are presented. Methods of evaluation and verification of the proposed reliability model using a laboratory model and available operational and service data are discussed. A proposal for a quantitative risk analysis of potential damage during the operation of the energy storage has been presented.

2

An effective hybrid method for analysis the large-scale reliability block diagram model

Ping Yashi, Ren Yi, Li Zhifeng, Yang Dezhen, Yang Chao

Eksploatacja i Niezawodność

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2023

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Vol. 25, no. 3

art. no. 169408

EN

The reliability block diagram (RBD) is a graphical tool used for reliability modeling and analysis in various industries, including shipbuilding, aviation, and aerospace. Typically, RBDs are transformed into Bayesian networks for quantitative analysis of systems. Bayesian networks are probabilistic graphical models that can capture the uncertainties and causal relationships in complex systems. They can provide various reliability metrics such as failure probability, mean time to failure, availability, etc. However, these techniques have several drawbacks, especially for large-scale models, such as being extremely time and memory-consuming. To address these issues, we propose a hybrid method for quantitative analysis of large-scale RBDs based on the structure identification approach and binary decision diagrams. Theoretical analysis and case verification demonstrate that the proposed method is significantly more efficient than the current one.

3

Contribution to study of the dependability of a drinking water system

Boumelita D., Ouerdachi L., Debbache N.-E.

Journal of Water and Land Development

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2018

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no. 38

11--18

EN

In order to ensure better availability of water resource to different users, we undertook a dependability study of system for drinking water supply. A real case study was done on the water supply network in the city of El Hadjarin Algeria. We started from the site modelling, which provided a calculation of a Hydraulic Criticality Index (HCI) in order to prioritize the importance of pipes in the network. Once the indices were calculated, a modelling procedure of reliability block diagram was applied. The objective was to study and analyse the existing network to measure the water availability problems and try to provide viable solutions. An action on the structural aspect and hardware may be required in order to ensure better availability of water and make the system more reliable. Spatial modelling is also proposed to be able to monitor different parts of the network where problems may occur.

PL

Celem zapewnienia lepszej dostępności różnym użytkownikom do zasobów wody podjęto badania nad niezawodnością systemu doprowadzania wody pitnej. Przykładem była sieć wodociągowa w mieście El Hadjarin w Algierii. Prace rozpoczęto od modelowania, co umożliwiło obliczenie krytycznego wskaźnika hydraulicznego (ang. hydraulic criticality index – HCI) w celu ustalenia priorytetu funkcji rurociągów w sieci. Po obliczeniu wskaźników zastosowano procedurę modelowania blokowego diagramu niezawodności. Celem badań było przeanalizowanie stanu istniejącej sieci, określenie problemów z dostępnością wody i zapewnienie rozwiązań możliwych do realizacji. Działania o charakterze organizacyjnym oraz inwestycyjnym mogą być niezbędne, aby zapewnić lepszą dostępność wody i uczynić system bardziej niezawodnym. Proponuje się także wykonanie modelu przestrzennego sieci, aby umożliwić monitorowanie różnych części sieci systemu.

4

The problems of modeling the reliability structure of the complex technical system on the basis of a steam�-water system of the engine room

Chybowski L.

Management Systems in Production Engineering

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2012

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nr 2 (6)

12-17

EN

In the paper the concept of a system structure with particular emphasis on the reliability structure has been presented. Advantages and disadvantages of modeling the reliability structure of a system using reliability block diagrams (RBD) have been shown. RBD models of a marine steam�-water system constructed according to the concept of �'multicomponent�', 'one component�f and mixed models have been discussed. Critical remarks on the practical application of models which recognize only the structural surplus have been dealt with. The significant value of the model by professors Smalko and Jaźwiński called by them �edefault reliability structure�f has been pointed out. The necessity of building a new type of models: quality�-quantity, useful in the methodology developed by the author's multi-criteria analysis of importance of elements in the reliability structure of complex technical systems.

PL

W artykule przedstawiono pojęcie struktury systemu ze szczególnym uwzględnieniem struktury niezawodnościowej. Przedstawiono zalety i wady modelowania struktury niezawodnościowej systemu z wykorzystaniem blokowych schematów niezawodności (RBD). Przedstawiono modele RBD okrętowego systemu parowo-wodnego zbudowane wg koncepcji modelu „wieloelementowego”, „jednoelementowego” i mieszanego. Przedstawiono krytyczne uwagi dotyczące praktycznego zastosowania modeli ujmujących jedynie nadmiar strukturalny. Wskazano na istotną wartość modelu autorstwa profesorów Jadźwińskiego i Smalko nazwanego przez nich „domyślną strukturą niezawodnościową”. Wskazano na konieczność budowy nowego typu modeli: jakościowo-ilościowych przydatnych w rozwijanej przez autora metodyce wielokryterialnej analizy ważności elementów w strukturze niezawodnościowej złożonych systemów technicznych.

5

Apply FMEA modeling to a floating ecological desalination unit

Dagkinis I., Lilas T., Nikitakos N.

Journal of Polish Safety and Reliability Association

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2011

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Vol. 2, No. 1

73--82

EN

Water scarcity in small Aegean islands is considered a major problem for their development. On the other hand high potential renewable energy sources are available. Therefore a floating desalination unit was developed in order to treat the problem in an ecological manner. The floating unit has been operating for four years at sea close to a small island. Marine environment and autonomous remote operation led to a more complex design with several sensors and safety mechanisms. This paper illustrates and applies Failure Modes and Effects Analysis (FMEA) modeling to Floating Ecological Desalination Unit. FMEA is based on monitoring data and also taking into account failure dependencies between components during the assessment of desalination system reliability. Then two systems, one with safety mechanisms and one without are analyzed by Reliability Block Diagrams (RBD) and the reliability of each system is computed. The comparison between a simple system and the remote autonomous system illustrates the implications of the additional monitoring mechanisms and the impact of these mechanisms to reliability and risk assessment on the floating wind powered offshore desalination unit.