Marek ŁOBODA, Krzysztof LENARCZYK, Bogumił DUDEK
Lightning hazard of EHV overhead lines and optimization of lightning protection and live working
Made is an analysis of lightning hazards and statistics relating to 220 and 400 kV transmission lines shutdowns in Poland in the years 2010-2016 caused by atmospheric ground discharges. Additionally, discussed are problems connected with taking into consideration the lightning hazards during realization of live working on power lines. Characterized are also basic features of an atmospheric discharges automatic detection system on the territory of Poland and possibilities to use data coming from this system for overhead power lines lightning protection as well as during planning and performing of live working.
Keywords: lightning hazards, 220 and 400 kV transmission lines, live working, atmospheric discharges automatic detection system
Małgorzata GÓRCZEWSKA
Selection of lighting methods in retail units
In many interiors the lighting is decisive for their functionality and obviously retail units belong to such category. The light performs in them multiple functions resulting from the necessity to provide adequate working conditions for the staff and also from the need to present properly the offered goods and services to the clients. The functions of the light are also shaped by the growing awareness of users and designers aided by development of the modern lighting technologies.
Keywords: lighting, standards and recommendations, lighting in retail units interiors, goods display
Maria CECOTKA
Role of the regeneration in repairs on the example of the Elektrownia Bełchatów experience
Operation of cooperating machines and devices cause a need to replace of their parts and subassemblies. To minimalize efforts and limit the creation of waste and consuming new materials, and hence protect the environment, a regeneration of consumed elements is applicable. Depending of the detail type, the operating environment, material and the cooperating elements the suitable technology of regeneration is selected. At this paper we present exemplary methods of parts regeneration used in PGE GiEK S. A. Oddział Elektrownia Bełchatów.
Keywords: operation of power plant machines and devices, methods of regeneration, PGE GiEK S. A. Oddział Elektrownia Bełchatów
Justyna KOZIARSKA, Andrzej KUREK, Tadeusz ŁAGODA
Comparison of different fixed characteristics of 16Mo3 steel for tension-compresion and pendulum bending
The article presents the fatigue characteristics for tension-compression and bending of 16Mo3 steel. On the basis of own research as well as taken from the literature, the results of tension-compression and bending were compared. On the graphs, it can be concluded that basis of the higher fatigue life will be obtained in case of bending.
Keywords: the fatigue characteristics of 16Mo3 steel, tension-compression, pendulum bending
Marzena M. LACHOWICZ, Maciej B. LACHOWICZ
Influence of sigma phase on slings made of heat resistant X8CrTi25 steel cracking under the operating conditions
The article presents the investigation results of X8CrTi25 steel used for slings of superheater pipelines. It has come for multiple crack during their exploitations with creating of brittle fractures. The cause of the steel brittleness was changes in the microstructure of the material, which lead to the formation of the sigma phase in the form of a grid on the grain boundaries. As a consequence, the very low plastic properties of the steel applied to the slings and their damage has archieved.
Keywords: investigations of X8CrTi25 steel, the slings of pipelines, cracks of brittleness steel, sigma phase
Katarzyna MAKOWSKA, Zbigniew L. KOWALEWSKI, Paweł ZIÓŁKOWSKI, Janusz BADUR
The evaluation of the degree of the damage of exploited turbine blades with the use of the signal of the Barkhausen noise
The degree of the degradation of material of steam turbine blades using the magnetic method has been analyzed in the paper. The relationships between the time of the operation of turbine blades and parameters of the Barkhausen noise have been identified. Results from the area of the leading edge of the blade and from the area of the trailing edge have been compared. The influence of the plastic deformation in consequence of the exploitation and the disassembly on the signal level of the noise has been described.
Keywords: the degradation of steam turbine blades, the signal of the Barkhausen noise
Andrzej RUSIN, Michał BIENIEK, Adam WOJACZEK, Maciej ROSKOSZ, Rafał BUDZISZ, Tomasz SKOCZYLAS
Application of the spt method in assessment of operational risk of turbine rotors
Extending time and changing the nature of the operation of coal power units is a serious problem for both the service department and the departments responsible for diagnostics and repairs in power plant. Emerging new risks require extending existing standard diagnostic tests. The article discusses the SPT method of testing micro samples to estimate the change in mechanical properties of rotor steels due to long-term operation. The application of the studies results to the assessment of the increase of turbines operational risk has been shown.
Keywords: the SPT method of testing micro samples, mechanical properties of rotor steels
Andrzej RUSIN
Non-destructive testing of the steel metallographic microstructure in quantitative assessment of operational risk of power unit elements
In the power sector, a large number of operating coal-fired power units are characterized by a relatively long service life. These power units often constitute the basic source of energy in individual national electric power systems; this implies that their reliability affects the reliability of the entire system of a given country. Therefore, the assessment of the current technical state of the power unit elements and of the risk related to their further operation is an issue of considerable importance. In this paper, we present an analysis of the assessment of the probability of the failure of the critical element of the power unit. The method for estimation of the component probability of creep failure using non-destructive testing of the steel metallographic microstructure is proposed.
Keywords: the critical elements of the power unit, the assessment of the probability of the failure, non-destructive testing of the steel microstructure
Łukasz SARNIAK, Rafał MOLAK, Barbara ROMELCZYK, Piotr GARYGA, Krzysztof PRZEPADŁO, Andrzej ZAGÓRSKI
Interpretation of test results of miniature samples obtained semi-destructively from steam turbine rotors
Accurate evaluation of the turbine rotor material degradation requires specialized material testing. The use of a miniaturized specimens allows the assessment of the rotor material degradation effects on its mechanical properties. The paper presents a methodology for semi-destructive sampling the material and the methodology of mechanical testing of the obtained material with the use of miniaturized specimens such as Miniature Specimen Tensile Test (MSTT). At the same time, the paper discusses interpretation of the tests results in terms of the dependence of material properties on the sample size, called “scaling effect”.
Keywords: steam turbine rotors, evaluation of material degradation,
methodology for sampling the material
Zdzisław ŚLODERBACH
The enthalpy and entropy as criterial quantity of critical state during plastic deformations of metallic materials?
In the article a special form of the thermodynamic potential of the free energy (for metallic materials) for the case of the thermoplastic body with the isotropic hardening was introduced. Author demonstrated, that energy stored of the plastic deformation (s.e.p.d), can perform the certain useful role, being used for an evaluation e.g. of state of material and state of the process of the plastic forming of metals and their alloys. Part of the work is devoted for stream of the entropy („production” of entropy) and her quantities. Author stated that the time of life of every power system was determined by the increase in the entropy of this system. Because the entropy is certain of „clock” measuring the time of life of the system. If power system (technical system) is supposed to have a long life, then a production of the entropy in this system should be minimized.
Keywords: the time of life of power system, enthalpy, entropy
Piotr TOKARCZYK, Mariusz WOŹNIAK, Janusz BADUR, Tomasz KOWALCZYK, Paweł ZIÓŁKOWSKI
Issues of the temperature of water suplied to hydro ejector and its influence on performance of steam turbine condenser
The aim of the paper is to investigate the issues of the temperature of water suplied to hydro ejector and its influence on performance of steam turbine condenser. The 18K380 steam turbine condenser air extraction system using hydro ejectors has been analised. Motivation for the analysis was a need of improvement of the energy conversion ratio of the power plant. To achieve this goal it was necessary to establish efficiency of each subsystem of the energy cycle. The air extraction system is not a highly power consuming system but it has great impact on the steam cycle efficiency by influence on the condensation temperature. The air extraction system effectiveness depends on a weather conditions, exactly on the ambient temperature, which raises the question whether it is worth to modernize the hydro ejectors. To establish the vacuum system effectiveness a new innovative mass flow measuring system has been implemented to measure an air-steam mixture flow and the fraction of the air mass in the mixture.
Keywords: hydro ejector, influence of the temperature of water suplied, the 18K380 steam turbine condenser
Paweł TRACZ, Krzysztof WACŁAWIAK, Przemysław SOKOŁOWSKI
Dynamic and kinematic analysis of selected structural features of impact mechanisms used in industrial electrostatic precipitators
This article is about a fragment of the issue which concerns electrostatic precipitators’ improvement of dust removal efficiency by using different design solutions of tumbling hammers’ mechanisms. This paper presents results of dynamics and kinematic analysis of collecting plates’ tumbling hammer. The influence of the mass on the value of impulse of hammer impact force was determined.
Keywords: industrial electrostatic precipitators, impact mechanisms, collecting plates’ tumbling
Paweł ZIÓŁKOWSKI, Janusz BADUR, Paweł JÓŹWIK, Zbigniew BOJAR, Michał STAJNKE, Sebastian KORNET, Piotr Józef ZIÓŁKOWSKI
Issues in modelling of hydrogen production for energy industry applications by methanol decomposition in innovative thermocatalytic reactor made from Ni3Al intermetallic alloy
This paper concerns the issues of the process hydrogen production modelling by methanol decomposition in the thermo-catalytic reactor on the intermetallic phase of Ni3Al. At the current load of steam turbine and cooperation with renewable energy sources, more detailed computational tools modelling chemical reaction are required, which allow determining the ability of storage electrical energy in fuels. This article describes the results of interaction Ni-based foils with flow which exhibit extremely high catalytic activity in methanol decomposition. The numerical simulation has been performed via CFD procedure with extension including increased chemical reactions rate on an interphase between fluid and solid. Presented analysis should be considered as satisfied and promising in the process of energy conversion from fuel to electric energy and reversly.
Keywords: thermocatalytic reactor made from Ni3Al intermetallic alloy, hydrogen production, methanol decomposition