IFE Brage
Not a member yet
1015 research outputs found
Sort by
Two-phase gas-liquid flow in concentric and fully eccentric annuli. Part II: Model development, flow regime transition algorithm and pressure gradient
Get PDFacceptedVersio
Chaos: A new mechanism for enhancing the optical generation rate in optically thin solar cells
Get PDFpublishedVersio
Conceptual Design of Yttrium Oxyhydrides: Phase Diagram, Structure, and Properties
No full textsubmittedVersio
McStas and Scatter Logger driven calculations of prompt gamma shielding for neutron guides
Get PDFMcStas ScatterLogger component bundle was adapted for evaluating a contribution to dose rate around neutron guides arising from prompt gamma radiation accompanying neutron capture in the supermirror guide coating upon specular reflection. Thickness of typical shielding materials needed to reduce this contribution to the desired level can be now evaluated directly from running a ray-tracing simulation of the instrument in McStas. An overview of the corresponding modifications to the existing McStas components and description of the newly written supplementary ones is given together with examples and use instructions.publishedVersio
Knowledge basis for repair contingency of pipelines - Final report
Get PDFThe RCN competence project ROP was initiated in January 2014, with the main objective to establish basic knowledge on subsea hyperbaric repair welding and degradation of clad and lined pipes, as well as C-Mn steel. The project is motivated by the need for improving the contingency situation and increase the research effort related to clad pipe and CMn pipeline repair in the Norwegian Continental shelf. The research partners have been SINTEF, IFE and NTNU, the industry partners are Equinor, Gassco, Technip FMC, EFD Induction and POSCO. This report summarizes the results from all work packages, a PhD thesis that was finalized in 2018 and post doc work finalized in February 2020. The work packages are: WP1 Structural Integrity, WP 2 Material and process modelling, WP3 Technical solutions and WP4 Demonstrators. An overview of the publications produced in the project is also given.acceptedVersio
Method for detecting aging related failures of process sensors via noise signal measurement
Get PDFIn this article we examine the methods for detecting and predicting aging related process sensor failures by analyzing the noise of the sensor output signal. The study uses data from non-differential and differential pressure transmitters used in the pressure and water level measurements of the reactor pressure vessels of units 1 and 2 of the Olkiluoto nuclear power plant in Finland. The article contains a review of the current methods for detection of sensor failures. Additionally, we present a new method for detecting changes in the sensor output signal. The method creates fingerprints of the power spectra of the sensors by using Principal Component Analysis (PCA). The changes in these fingerprints together with the measurements of the redundant sensors can be used to detect indications of some of the impending sensor failures. In the experimental study we are able to produce stable fingerprints for both the non-differential and differential pressure transmitters. Also, a potential failure in one of the differential pressure transmitters in Olkiluoto unit 2 is detected by inspecting the fingerprints and analyzing the spectral changes of the transmitter output signal.publishedVersio
Corrosion, Scaling and Material Selection in Deep Geothermal Wells – Application to IDDP-2
Get PDFIn order to make the world’s energy consumption sustainable there is a need for reducing emissions of CO2 and to shift towards renewable energy sources. Geothermal energy has a large potential in certain parts of the world. One example is Iceland, where the reservoir in IDDP-2 is around 427°C and 340 bar at a final well depth of 4650 m. This makes it attractive as a geothermal reservoir of high enthalpy supercritical water with the potential for conversion of large amounts of high temperature deep geothermal energy. Production from the IDDP-2 is scheduled to start in 2019, and hence the fluid composition is not known. Using available data for nearby wells, and in particular IDDP-1, an estimate can still be made. A combination of high temperature and pressure, the presence of corrosive agents (such as HCl and H2S), a low pH and reducing conditions gives rise to challenges related to material selections. This paper summarizes part of a desktop case study that addresses corrosion and scaling issues for conditions relevant for the IDDP-2 geothermal well. The reservoir and well data are based on temperature measurements inside the well and assumptions on a hydrostatic reservoir. The total depth of the well is 4650 meters. Based on this a model is set up for temperature and pressure profile along the well. Knowledge gaps, such as lacking solubility data and corrosion rates at supercritical conditions are pointed out. Paper reproduced with permission from CORROSION/2019 Annual Conference and Exhibition. www.nace.orgpublishedVersio