Waste Disposal Plant Application of Overhauled and Regenerated Steam Turbine

Abstract

The present work aims to evaluate and identify the methodology for reusing disused steam turbines in waste-to-energy plants. First, the methodology for assessing the state of the turbine will be identified through a complete overhaul of the same turbine, with attention to the components subjected to greater wear, to evaluate the possibility of reconditioning. The reference turbine will be a disused, malfunctioning and old-tech machine, often considered as “waste”, but with great potential, such that it was evaluated and finally decided to enhance it through reconditioning. The turbine overhaul operations are characterized by a first analysis of the typical failures of steam turbines, identifying the components most exposed to breakage and a deep accurate inspection has been carried out. To accomplish this task, it is necessary to know, through a completed study, the “history” of the machinery, identifying the components of the steam turbine with the highest incidence of failure. Consequently, the frequency of occurrence and the severity of the damage can be evaluated. It will be necessary to put attention to the components that present a greater risk of breakage, identifying the checks to be carried out. All possible fault chains will then be studied, highlighting the main cause and the various maintenance periods to which the turbine has been subjected. Once the functionality of the turbine has been verified, the possibility of its reuse will be evaluated, for example for geothermal plants or for waste-to-energy. Once the turbine modernization operations have been completed, the possibility of its reuse in a waste treatment plant will be analyzed. So, a pilot power plant will be studied and the possibility of using the modernized turbine within the same plant will be verified, evaluating through simulations (not included in this work) the actual feasibility and functionality of the choice made. Given the current trend in the cost of energy is growing, with a consequent increase in revenues obtainable from the use of a reconditioned turbine, a comparison of the profits deriving from the use of a revised turbine compared to the new one, also considering the time necessary for economic recovery, will be carried out. In the present work, therefore, authors wanted to underline the importance of treating waste as a source of added value (in this case the disused driving machine) and a source of energy (municipal solid waste), rather than as tasks that inevitably weigh on the finances of the State and of the individual citizen. Finally, the main goal of the work has been achieved. In fact, proven by the data, it is possible to reuse turbines after having overhauled them and take advantage in different plant applications.