FAILURE MODE EFFECTIVE ANALYSIS IN A BOILER USING COMBINATION OF EVENT TREE AND FAULT TREE ANALYSIS

Boilers are valued highly in many industrial industries and are expensive assets. In addition to their initial expense, they demand a large maintenance budget in order to guarantee output in respectable and safe working conditions. In order to avoid extreme repercussions, including the loss of lives, these assets must be carefully operated under experienced, well-trained supervision and subject to rigorous maintenance schedules and safety activities. However, this investigation is carried out with the help of the FMEA method, considering the previous literature\u27s studies of boiler accidents in Asia so far. Phase I has detailed information about boilers and Asian boiler accidents, and this research paper explains its nature. Subsequently, based on the data obtained in Phase I, an FMEA model will be developed in Phase II to highlight key boiler safety points. This research helps boiler manufacturers, boiler-related entrepreneurs, and boiler users to ensure maximum safety and identify any new things related to boiler safety

Towards multi-model approaches to predictive maintenance: A systematic literature survey on diagnostics and prognostics

The use of a modern technological system requires a good engineering approach, optimized operations, and proper maintenance in order to keep the system in an optimal state. Predictive maintenance focuses on the organization of maintenance actions according to the actual health state of the system, aiming at giving a precise indication of when a maintenance intervention will be necessary. Predictive maintenance is normally implemented by means of specialized computational systems that incorporate one of several models to fulfil diagnostics and prognostics tasks. As complexity of technological systems increases over time, single-model approaches hardly fulfil all functions and objectives for predictive maintenance systems. It is increasingly common to find research studies that combine different models in multi-model approaches to overcome complexity of predictive maintenance tasks, considering the advantages and disadvantages of each single model and trying to combine the best of them. These multi-model approaches have not been extensively addressed by previous review studies on predictive maintenance. Besides, many of the possible combinations for multi-model approaches remain unexplored in predictive maintenance applications; this offers a vast field of opportunities when architecting new predictive maintenance systems. This systematic survey aims at presenting the current trends in diagnostics and prognostics giving special attention to multi-model approaches and summarizing the current challenges and research opportunities

Degradation modeling and condition-based maintenance of boiler heat exchangers using gamma processes

Boiler heat exchanger tubes erode over time, leading to costly leaks and capacity loss as damaged tubes are taken out of operation. These losses can be recovered by replacing the heat exchanger, albeit at significant capital cost. Deciding when to replace the heat exchanger is greatly aided by prediction of the future capacity and downtime losses associated with tube thickness degradation. However, current thickness loss models study a single phenomenon and therefore provide oversimplified point predictions of thickness loss. Additionally, the available models do not account for uncertainty in the degradation process and therefore cannot provide information on future tube failure probabilities required for decision making. In this paper a novel degradation model is presented using a physical erosion model and a Gamma process to account for the uncertainties in the thickness degradation process. Subsequently, new algorithms are presented to predict the probability of key events in boiler operation: the bursting of a tube during operation and the plugging of a tube preventively during a scheduled shutdown. Finally, a condition-based maintenance methodology is presented based on the new degradation model and applied to a real-world case study of a boiler operating in a real Australian sugar production facility