Dominik DUDA, Maksymilian PRZYGRODZKI, Piotr RZEPKA, Mateusz SZABLICKI
Analysis of parameter changes of a wind farm turbine being connected to a distribution network
Implementation of changes in the planned to be connected to the Polish Power System wind farm after having obtained grid connection requirements does not necessarily needs moving for such requirements once again. As shown hereby, the change of wind turbine type needs verification only in some analytic areas that influence a power system. The existing differences between the comparable wind turbines first of all refer to rated power, control range of a power factor, wind turbine output
voltage, quality parameters of generated electric energy and allowable operating range during fault states in the grid. Analysis of those parameters interactions leads to correction of the at first scheduled systems of an inner farm network operating system, protection adjustments and to activation of proper turbine controller functions. All in all, the investment can be carried on in the frames of the obtained grid connection requirements.
Keywords: wind farms, grid connection, alteration of turbine data with no connection requirements change
Krzysztof DRAGAN, Michał DZIENDZIKOWSKI, Michał STEFANIUK
Integrated computing environment for ultrasonic imaging of composites
Presented is an approach for ultrasonic imaging of composite structures. These structures are more and more often used both in aerospace and power industries (especially in case of wind farms) therefore development of their nondestructive testing methodology is essential. Reliable evaluation of structural damage scale (e.g. disbonds, delaminations or foreign object inclusions) as well as characterization of a composite itself are in the scope of the hereby described methodology. Taken up are many problems referring to multiple inspection or signal processing. In particular the authors concentrate upon some statistical and numerical methods enhancing diagnostic parameters selection and supporting time domain signal analysis as well as digital image processing. Shown are problems and advantages of the proposed signal processing methods. Presented are also possibilities of the 3D composites characterization and the measurement results obtained in wind power industry (wind turbine blades inspection).
Keywords: composites inspection, low energy impacts, statistical image processing, wind energy
Jan DAMPC, Marek SZKODO
Model testing of sulphur compounds addition to the CCR platforming installation charge influence on the steel X11CrMo9-1 furnace pipes dusting process
Presented are testing results of X11CrMo9-1 steel which has been in operation for 10 years in the Grupa Lotos SA in Gdańsk CCR platforming installation and then, in laboratory conditions, exposed to sulphurization for 166 hours in the temperature of 600°C. The sulphurization was carried on in the H2-H2S gas mixture with 4,1•10-14 atm sulphur fumes pressure which is of a whole order of magnitude less than the FeS dissociation pressure. Despite the fact that sulphurization was carried on in conditions excluding forming of iron sulfide, the testing results proved that already after 166 hours of exposure in reaction mixture the iron and chromium sulfides started forming in the 11XCrMo9-1 steel. Sulfide precipitations arise under the layer of fine dispersive carbides located directly near the
steel surface. Formation of sulfide scale in this place is most likely caused by penetration of hydrogen sulfide through the porous carbide layer resulting in the hydrogen sulfide pressure increase, followed by sulphur fumes pressure increase in slots and capillaries occurring between carbide layer and the rest of the supersaturated with coal upper layer, up to a value enabling formation of the sulfide scale.
Keywords: CCR platforming, installation piping degradation, metal dusting, X11CrMo9-1 steel, H2S addition
Maciej ROSKOSZ, Krzysztof FRYCZOWSKI
Possibilities of using changes in magnetic properties to assess the stress state of boiler steels on the example of P265GH steel
Analysed is an impact of applied and residual stress on the Barkhausen field effect and on residual magnetic field (RMF) in the P265GH steel. Examined are flat notched samples in the scope of elastic and plastic strain. Studied are relationships between the uniaxial tensile load (under
loading and after unloading) and the values which quantitatively describe the Barkhausen noise (number of counts, the maximum rms value, energy) and the RMF component gradients. Good quantitative relationships between applied stress and the Barkhausen noise are found. Shown is the possibility of identifying areas with plastic deformations using both the RMF and the Barkhausen noise. It is also possible to quantitatively assess the degree of plastic strain of the material. The combination of fast identification of potentially dangerous areas based on the RMF measurements with the existing algorithms for stress assessment based on the Barkhausen noise makes it possible to develop an efficient, magnetic method of assessment of the state of ferromagnetic components.
Keywords: magnetic properties of a steel, Barkhausen noise, assessment of ferromagnetic components state
Dominik KUKLA, Andrzej ZAGÓRSKI, Paweł GRZYWNA
Assessment of fatigue processes development connected with local strains on the example of P91 steel for power industry
Presented are results of investigations connected with an assessment of development of fatigue failures of P91 steel samples under the influence of variable cyclic loading. The investigations referred to quantitative failure assessment on the basis of registration and analysis of fatigue hysteresis loop changes in successive loading cycles. According to the elaborated algorithms, failure parameters are determined on the basis of medium strains development and the strain amplitude. Analysis of these variables allows to define two mechanisms of fatigue degradation development in investigated steel. One is the mechanism called ratcheting and connected with generation of local plastic strains around microstructure elements, the other is a cyclic plasticity connected with microslips preceding the origination of slip bands. Described is microscopy research (SEM) of fatigue samples both in the scope of metallography and of fractography that enabled indication of microstructural aspects of fatigue failure development mechanisms.
Keywords: fatigue failures of steel, hysteresis loop registration, degradation development mechanisms
Piotr ŚMIETANA, Jerzy LASKA
Application of the MMM method in overhaul diagnostics of steam turbine elements
The post-service condition of power machines elements working under creep and thermo-mechanical fatigue conditions, is most commonly assessed before and during the overhaul on the basis of conventional non-destructive methods. The typical identified defects like discontinuities or erosive-corrosive material losses do not constitute a basis of overhaul technology determination and of a prognosis elaboration for further operation of these elements. One of the rapid and simple ways to preliminary assess the state of internal stresses and exploitation history of an element is the metal magnetic memory method (MMM). Magnetic anomalies identified by the MMM method are usually the right places for further investigations like geometrical measurements, metallographic observations, hardness measurements or destructive testing (extraction of samples). Such inspection methodology facilitates the improved detectability of structural defects and stress concentration zones, increasing the reliability of commissioned turbine elements. Discussed are examples of using the MMM method as a supportive diagnostic tool. Presented are inspection results of rotor shafts and discs as well as of steam turbine casings. Described is also the use of this method in acceptance tests of heat-treated turbine casings and straightened rotor shafts.
Keywords: steam turbines, overhaul diagnostics, metal magnetic memory method (MMM)
Tomasz SAMBORSKI, Andrzej ZBROWSKI
The model of a stand for detection of internal material faults in the roller bearing rings
Presented is the model of a mechatronic stand for detection of the inner material faults occurring in the rings of roller bearings that was developed at the Institute for Sustainable Technologies – NRI in Radom. The stand consists of three basic modules: input module responsible for proper orientation of tested bearing before the test process, detection module equipped with two scanning heads and the output one responsible for the separation of good and bad products. In the presented solution, adapted for application in the production line of conical roller bearings, the eddy current method is used. The developed device, thanks to application of programmable mechatronic elements, allows wide range shaping of detection parameters related to the variable shape of tested bearing series
in the process of 100% of stock testing.
Keywords: roller bearings, internal faults, eddy currents, bearing rings
Ireneusz Wróbel
Reconstruction engineering of steam turbine blades used in power industry
Described is the process of reconstruction engineering of blades used in steam turbines. Sugggested is the appropriate methodology for blade copy building basing on a worn out blade gained during the overhaul of a turbine. Presented is the whole process of a blade reconstruction, beginning with 3D scanning, then scan results processing and ending with building of the whole CAD model. The process has already been implemented into practice by blade producer cooperating with the author of this paper.
Keywords: steam turbines, overhauls, blade reconstruction
Bogdan SZTUROMSKI, Wojciech JURCZAK
Wear-and-tear of ship aluminum alloy 7020
Presented is the methodology of determining the aluminum alloy AW- 7020 plastic characteristics (strain hardening) of the sample taken from a 25 years old ship superstructure for the needs of numerical simulations in the CAE program. Material characteristics is determined on the basis of results obtained during the static tension test of flat samples with real corrosion defects.
Keywords: aluminum alloy AW-7020, tension test, plastic characteristics, CAE
Agnieszka TUKALSKA
Energy policy in the European Union
The EU efforts aiming at integration in the field of power industry go back as far as April 18, 1951, when in Paris the Treaty establishing European Coal and Steel Community was signed but only recently, on the strength of the last reform enforced by the Treaty of Lisbon, the energy policy has been provided a legal basis for its activities. The legal basis now consists of the two treaties - the Treaty establishing the European Atomic Energy Community signed in Rome on the 25 March, 1957, and, signed on the same day, the Treaty on the Functioning of the European Union (TFEU). All problems concerning energy policy before the enforcement of the Treaty of Lisbon were until then regulated by directives. Only with the present legal status we can speak about separating of energy policy as the new sphere of activity on the EU level. Analysing the art. 194 of the TFEU we come to a conclusion that the EU energy policy has got four aims: ensuring the energy market functioning, ensuring the safety of energy supplies within the EU, supporting energy effectiveness and energy saving as well as developing of new and renewable forms of energy and supporting interconnections between energy networks. Besides that, art. 194 par. 1 of the TFEU defines two basic principles of energy policy i.e. the need to preserve and improve the environment and the principle of
solidarity.
Keywords: European Union, legal bases of the EU energy policy
Olga Anna ORYNYCZ
Production of liquid biofuels as the energy source for transport
Road transport uses large quantities of petroleum-based liquid fuels that contributes to the increase of greenhouse gases emission. In the perspective of the near future we can expect further growth in biofuels consumption as compared to the use of diesel oil. It results from the desire to improve the energy safety, ecological advantages and the necessity of energy raw materials saving. Petroleum has the largest share among fuels in the consumption of final energy. The most commonly used alternative fuel important for the transport sector are methyl esters of higher fatty acids called biodiesel. Application of biofuels should be preceded by analyses determining the influence of individual production factors on the final effect. Selection of elementary technological processes decides on efficiency of production system both in energy and economic sense.
Keywords: biofuels, biodiesel, energy, alternative energy sources