211 research outputs found

    Automatic condition monitoring system for crack detection in rotating machinery

    Get PDF
    Maintenance is essential to prevent catastrophic failures in rotating machinery. A crack can cause a failure with costly processes of reparation, especially in a rotating shaft. In this study, the Wavelet Packets transform energy combined with Artificial Neural Networks with Radial Basis Function architecture (RBF-ANN) are applied to vibration signals to detect cracks in a rotating shaft. Data were obtained from a rig where the shaft rotates under its own weight, at steady state at different crack conditions. Nine defect conditions were induced in the shaft (with depths from 4% to 50% of the shaft diameter). The parameters for Wavelet Packets transform and RBF-ANN are selected to optimize its success rates results. Moreover, ‘Probability of Detection’ curves were calculated showing probabilities of detection close to 100% of the cases tested from the smallest crack size with a 1.77% of false alarms.The authors would like to thank the Spanish Government for financing through the CDTI project RANKINE21 IDI-20101560

    Annual Report 2021 of the Institute for Thermal Energy Technology and Safety

    Get PDF
    The annual report of the Institute for Thermal Energy Technology and Safety of KIT summarizes its research activities in 2021 and provides some highlights of each working group of the institute. Among them are thermal-hydraulic analyses for fusion reactors, accident analyses for light water reactors, innovative nuclear concepts, and research on innovative energy technologies like liquid metal technologies for energy conversion, hydrogen technologies and geothermal power plants. Moreover, the institute has been engaged in education and training in energy technologies, illustrated by e.g. training in nuclear engineering by the Framatome Professional School

    Nuclear Power

    Get PDF
    The world of the twenty first century is an energy consuming society. Due to increasing population and living standards, each year the world requires more energy and new efficient systems for delivering it. Furthermore, the new systems must be inherently safe and environmentally benign. These realities of today's world are among the reasons that lead to serious interest in deploying nuclear power as a sustainable energy source. Today's nuclear reactors are safe and highly efficient energy systems that offer electricity and a multitude of co-generation energy products ranging from potable water to heat for industrial applications. The goal of the book is to show the current state-of-the-art in the covered technical areas as well as to demonstrate how general engineering principles and methods can be applied to nuclear power systems

    Experimental and computational investigation of flow of pebbles in a pebble bed nuclear reactor

    Get PDF
    The Pebble Bed Reactor (PBR) is a 4th generation nuclear reactor which is conceptually similar to moving bed reactors used in the chemical and petrochemical industries. In a PBR core, nuclear fuel in the form of pebbles moves slowly under the influence of gravity. Due to the dynamic nature of the core, a thorough understanding about slow and dense granular flow of pebbles is required from both a reactor safety and performance evaluation point of view. In this dissertation, a new integrated experimental and computational study of granular flow in a PBR has been performed. Continuous pebble re-circulation experimental set-up, mimicking flow of pebbles in a PBR, is designed and developed. Experimental investigation of the flow of pebbles in a mimicked test reactor was carried out for the first time using non-invasive radioactive particle tracking (RPT) and residence time distribution (RTD) techniques to measure the pebble trajectory, velocity, overall/zonal residence times, flow patterns etc. The tracer trajectory length and overall/zonal residence time is found to increase with change in pebble\u27s initial seeding position from the center towards the wall of the test reactor. Overall and zonal average velocities of pebbles are found to decrease from the center towards the wall. Discrete element method (DEM) based simulations of test reactor geometry were also carried out using commercial code EDEM and simulation results were validated using the obtained benchmark experimental data. In addition, EDEM based parametric sensitivity study of interaction properties was carried out which suggests that static friction characteristics play an important role from a packed/pebble beds structural characterization point of view. To make the RPT technique viable for practical applications and to enhance its accuracy, a novel and dynamic technique for RPT calibration was designed and developed. Preliminary feasibility results suggest that it can be implemented as a non-invasive and dynamic calibration methodology for RPT technique which will enable its industrial applications. --Abstract, page iii

    Nuclear Power

    Get PDF
    The world of the twenty first century is an energy consuming society. Due to increasing population and living standards, each year the world requires more energy and new efficient systems for delivering it. Furthermore, the new systems must be inherently safe and environmentally benign. These realities of today's world are among the reasons that lead to serious interest in deploying nuclear power as a sustainable energy source. Today's nuclear reactors are safe and highly efficient energy systems that offer electricity and a multitude of co-generation energy products ranging from potable water to heat for industrial applications. The goal of the book is to show the current state-of-the-art in the covered technical areas as well as to demonstrate how general engineering principles and methods can be applied to nuclear power systems

    Development and application of spectroscopy techniques for monitoring hydrate and corrosion risks

    Get PDF
    Pipelines are used to transport hydrocarbons from production wells to different locations for various purposes (e.g. processing, refinery, power generation, etc.) and CO2-rich fluids from the emission sources for disposal in suitable geological storage sites. The presence of water in such hydrocarbon and/or CO2 transport pipelines may result in corrosion, ice and/or gas hydrate formation and even pipeline blockage, so the fluid system should meet certain dehydration and/or inhibition requirements. This work describes the development and application of different spectroscopic (UV-VIS and NIR) methods for identifying and controlling flow assurance issues relating to gas hydrate and corrosion. For hydrates, a Fourier Transform Near-Infrared (FTNIR) spectroscopy method using chemometric models was developed to measure the concentration of main hydrocarbon gases (Methane through butanes) under in-situ pressure (up to 13.8 MPa). This approach was then used for detecting initial signs of hydrate formation based on reduction in the concentration of some preferential components in the gas phase. Furthermore, injection of hydrate inhibitors based on the calculated/measured hydrate phase boundary, water cut, pressure and temperature conditions, and the amount of inhibitor lost to non-aqueous phases is a commonly used method for avoiding gas hydrates problems. Thus, it is crucial to monitor salt and inhibitor concentration in the fluids along the pipeline and/or downstream in order to optimise the injection rate. To address this requirement, a novel method was developed by combining UV and NIR spectra to predict the concentration of salt and hydrate inhibitors (THIs and KHIs) simultaneously in aqueous solutions. In the case of corrosion, the potential of visible spectroscopic technique was investigated for determining the pH in CO2/ CO2-rich mixtures saturated water, and CO2/ CO2-rich mixtures saturated NaCl solutions at pressures up to 15 MPa and temperature ranges from 293.15 to 323.15 K. Furthermore, we described and evaluated a model that uses a robust thermodynamic basis for describing the solubility of gases in the aqueous phase and Pitzer’s theory for determining the activity coefficients of the ionic species involved. The model was tested in concentrated NaCl solutions under CO2 pressure at realistic industrial operating temperatures. The developed spectroscopic techniques were experimentally evaluated at lab conditions. Results show that these techniques can be applied to detect initial signs of hydrate formation, to optimise hydrate inhibitor injection rate, and to measure the pH of CO2 saturated H2O/brine systems in the downhole/wellbore/pipeline region

    Gas Turbines

    Get PDF
    This book is intended to provide valuable information for the analysis and design of various gas turbine engines for different applications. The target audience for this book is design, maintenance, materials, aerospace and mechanical engineers. The design and maintenance engineers in the gas turbine and aircraft industry will benefit immensely from the integration and system discussions in the book. The chapters are of high relevance and interest to manufacturers, researchers and academicians as well
    corecore