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The main purpose of this work is the development of a diagnostic procedure for radial turbines installed on internal combustion engine turbochargers. The study is part of a wider research activity regarding the development of diagnostic systems dedicated to cogenerative engine. The proposed procedure is able to formulate a judgment about the turbines efficiency through the real-time evaluation of an effective performance index, only on the basis of pressure measurements across the turbine. Such diagnostic procedure was developed in reference to experimental data gathered in two acquisition campaigns performed before and after a consistent maintenance intervention on engine turbines. The first part of the work approaches turbine failures issues, while in the second one experimental results are presented and analyzed. Finally, the study deals with the definition of some turbine health state indices and their test in reference to the experimental data cited above. A particular index was validated as useful to be implemented in a diagnostic procedure for detection of turbine degradation. [ABSTRACT FROM AUTHOR]

Abstract: A diagnostic procedure is presented purposely for the turbocharging system of 1MW internal combustion engine (I.C.E.) and specifically, for the filters and compressor modules. This study is part of a wider research activity, concerning the development of a diagnosis system dedicated to the cogenerative I.C.E. installed at the Engineering Faculty in Perugia. Firstly a 1-D thermodynamic model of the CHP engine working fluid was developed to simulate failure conditions of the turbocharging groups, which are not directly replicable on the I.C.E. to avoid plant stoppage. This model is able to simulate the degradation in performance of the engine components. It also takes into account the effect of compensation which the regulation system activates in case of efficiency loss or failure relative to filters or compressors. In order to identify and assess such failures, the fuzzy logic was chosen as the tool for the diagnosis system design. The developed diagnosis system displayed a good reliability degree with the 1-D thermodynamic model results, for operating conditions in correspondence of bad performance either on behalf of the filters or the compressor. Moreover, the procedure can be implemented in the plant monitoring system and provides in real-time diagnosis results about the status of the components and the need of maintenance, on the basis of few parameters already measured on the I.C.E. [Copyright &y& Elsevier]

Abstract: The issue of internal combustion engine (ICE) diagnosis attracts great interest because modern engines need continual control of the operational status, in order to obtain high efficiency in energy conversion and accurate control of the polluting emissions. In particular, in reference to an alternative ICE of 1MW, the present study relates the development, through the design of neural simulators, of the turbocharger maps to reproduce the operational states characterized by new&clean conditions and allowing the evaluation of particular “health state” indices of such a module. In detail, after an experimental campaign, turbocharger fundamental characteristics referred to new&clean conditions, such as the compressor isoentropic efficiency and the mass flow elaborated by the turbine, were evaluated at different operation conditions of the alternative ICE Subsequently, the neural simulators were developed through the training and test of different neural architectures. [Copyright &y& Elsevier]

Abstract: In the present study an innovative diagnostic system of the combustion process, developed especially for cogenerative reciprocating engines, is introduced. This work is part of a more wide research activity, dedicated to the development of diagnostic systems for energy plants. This system is based on the evaluation of the energy content of the vibration signal directly acquired on the cylinders head through the Discrete Wavelet Transform technique and the Parseval’s theorem. The system development and its test took place alongside a consistent maintenance work that has allowed to distinguish between different engine operative functioning, and, in particular, between good and bad conditions of the combustion chambers. Then, starting from the obtained results, a diagnostic system has been developed, basing on the acquired vibration signals and the operative engine load, in order to formulate for each cylinder a judgment about the quality of the combustion process. [Copyright &y& Elsevier]