Search results for: TURBINE TRANSMISSION SEALS - Bridge of Knowledge

Search

Search results for: TURBINE TRANSMISSION SEALS

Search results for: TURBINE TRANSMISSION SEALS

  • Reduction of pressure forces in turbine labyrinth seals

    Publication

    Przedstawiono nową metodę zmniejszani sił samowzbudnych typu aerodynamicznego. zastosowano ją do różnych typów nadbandażowych uszczelnień labiryntowych. Efektywność rdukcji sił samowzbudnych wynosiła nawet ponad 60%. Potwierdzone rezultay obliczeniami i eksperymentalnie.

  • Explanation of Reduction of Pressure Forces in Turbine Chamber Seals

    Publication

    The paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....

  • Explanation of Reduction of Pressure Forces in Turbine Chamber Seals

    The paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....

    Full text to download in external service

  • The Method of reduction of aerodynamic forces generated in turbine blade seals

    Publication

    The distibution of pressure in the seal gaps does not only affect the so called '' leakage losses'' and the turbine stage overall efficiency but also plays an important role in the generation of aerodynamic forces which may cause self-excited rotor vibrations. The paper describes a chamber seal applied for the reduction of the aerodynamic forces created in shroud seals. This kind of turbine seal was patented and tested.

  • Flows in turbine blade seals: CFD calculations versus experiment

    Publication

    Przedstawiono wyniki numerycznej analizy przepływu w uszczelnieniu nadbandażowym stopnia turbinowego. Rezultaty obliczeń porównano z danymi doświadczalnymi. Eksperymenty przeprowadzono na modelowej turbinie powietrznej przy różnych częstościach obrotów wału i różnym obciążeniu turbiny.

  • The Method of Reduction of Aerodynamic Forces Generated in Turbine Blade Seals

    Opisano metodę zmniejszania sił wymuszających drgania aerodynamiczne poprzez zastosowanie nowego uszczelnienia nadbandażowego typu komorowego. Efektywność stosowania uszczelnienia komorowego potwierdzono obliczeniami numerycznymi i badaniami eksperymentalnymi.

  • On the modelling of aerodynamic force coefficients for over-shroud seals of turbine stages

    This paper presents experimental investigations which made it possible to determine dynamic coefficients of labyrinth over-shroud seal of a model air turbine. The coefficients associate pressure forces with turbine rotor displacement, velocity and acceleration respective to turbine casing (linear model) and play important role in analyzing turbine-set dynamics. The obtained results indicated that involving serious errors can be...

    Full text available to download

  • Research into flows in turbine blade seals. Part I: Research methods

    Publication

    Opisano numeryczną i doświadczalną metodę badania przepływu w uszczelnieniu nadbandażowym stopnia turbinowego. Badania numeryczne przeprowadzono programem Fluent, a badania doświadczalne wykonano na powietrznej turbinie modelowej. Zamieszczono przykładowe wyniki.

    Full text available to download

  • Research into flows in turbine blade seals. Part II: Numerical analysis

    Publication

    - TASK Quarterly - Year 2003

    Przedstawiono wyniki badań numerycznych programem Fluent przepływów w uszczelnieniu nadbandażowym stopnia turbinowego. Badania wykonano przy zastosowaniu różnych typów siatek obliczeniowych, różnych rodzajów "zszywek" oraz różnych metod obliczeniowych (Mixing Plane, Sliding Mesh, Multiple ReferenceFrame).

    Full text available to download

  • Influence of the steam within seals and glands of the turbine on its rotor motion stability.

    Publication

    Przedstawiono metodę obliczania charakterystyk dynamicznych wpływu parowych uszczelnień turbin na ich dynamikę i stateczność ruchu wirników. Zarysowano model ''masowy'' uszczelnienia. Podano przykłady zastosowań.

    Full text available to download

  • Research into flows in turbine blade seals. Part III: Numerical calculations versus experiment

    Publication

    Przedstawiono wyniki badań doświadczalnych przepływów w uszczelnieniu nadbandażowym stopnia turbinowego, przeprowadzonych na powietrznej turbinie modelowej. Rezultaty te porównano z wynikami badań numerycznych z zastosowaniem programu Fluent.

    Full text available to download

  • Calculations of labyrinth seals with and without diagnostic extraction in fluid-flow machines

    Labyrinth seals are essential components of steam turbine unit constructions. Two types of labyrinth seals can be named, the first of which is the seal without diagnostic steam extraction, and the second – with extraction. The distribution of flow parameters along the packing is affected remarkably by the average seal clearance. The presence of diagnostic extraction leads to the equation system which is determinable and can be...

    Full text available to download

  • Balancing energy processes in turbine engines

    Publication
    • W. Balicki
    • P. Głowacki
    • S. Szczeciński
    • Z. Korczewski
    • A. Kozakiewicz
    • J. Szczeciński

    - Polish Maritime Research - Year 2014

    The article discusses the issue of balancing energy processes in turbine engines in operation in aeronautic and PDULQHSURSXOVLRQV\VWHPVZLWKWKHDLPWRDQDO\VHDQGHYDOXDWH EDVLFRSHUDWLQJSDUDPHWHUV7KH¿UVWSDUWSUHVHQWV the problem of enormous amounts of energy needed for driving fans and compressors of the largest contemporary turbofan engines commonly used in long-distance aviation. The amounts of the transmitted power and the effect RIÀRZSDUDPHWHUVDQGFRQVWUXFWLRQDOSURSHUWLHVRIWKHHQJLQHV RQWKHLUSHUIRUPDQFHDQGUHDOHI¿FLHQF\DUH evaluated....

    Full text available to download

  • Rotordynamic characteristics of a chamber seal

    Publication

    The paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal of a modernized type. The experiments were performed on a single-stage air model turbine of the impulse type. The experiments were performed on a single-stage air model turbine of the impulse type. The experimental data were compared with theoretical results obtained by means of CFD Fluent Code....

  • CFD analysis of fluid flow through the labyrinth seal

    Steam and gas turbines are some of the fundamental means of power generation. The energy efficiency of the turbines, however, is not satisfactory. Ever since the start-up of the first turbine in the world, engineers have been striving for their increased efficiency. Multiple solutions to the problem of steam loss in an operating turbine are available. The use of seals is one of them. Empirical methods or numerical calculations...

    Full text available to download

  • Operation evaluation method for marine turbine combustion engines in terms of energetics

    Publication

    An evaluation proposal (quantitative determination) of an y combustion turbine engine operation has been presented , wherein the impact energy occurs at a given time due to Energy conversion. The fact has been taken into account that in this type of internal combustion engines the energy conversion occurs first in the combustion chambers and in the spaces between the blade of the turbine engine. It was assumed that in the combustion...

    Full text available to download

  • ANALYSIS OF THE IMPACT OF MASS FLOW EXTRACTION ON THE CHANGE OF PARAMETERS IN A LABYRINTH SEAL USING THE STODOLA METHOD

    Labyrinth seals are an important element of a steam turbine set design. The use of diagnostic extraction makes it possible to control the operation of a seal by providing information on the thermodynamic parameters along the length of the seal. Diagnostic extraction has a considerable impact on the change of the parameters, the amount of the extracted mass. This article describes the dependence of pressure in the clearance downstream...

    Full text available to download

  • ANALYSIS OF THE IMPACT OF MASS FLOW EXTRACTION ON THE CHANGE OF PARAMETERS IN A LABYRINTH SEAL USING THE STODOLA METHOD

    Publication

    Labyrinth seals are an important element of a steam turbine set design. The use of diagnostic extraction makes it possible to control the operation of a seal by providing information on the thermodynamic parameters along the length of the seal. Diagnostic extraction has a considerable impact on the change of the parameters, the amount of the extracted mass. This article describes the dependence of pressure in the clearance downstream...

  • DESIGN ANALYSIS OF HYBRID GAS TURBINE - FUEL CELL POWER PLANT IN STATIONARY AND MARINE APPLICATIONS

    The paper concerns design analysis of a hybrid gas turbine power plant with a fuel cell (stack). The aim of this work was to find the most favorable variant of the medium capacity (approximately 50 MW) hybrid system. In the article, computational analysis of two variants of such a system was carried out. The analysis let to calculate capacity, efficiency of both variants and other parameters like flu gas temperature. The paper...

    Full text available to download

  • Technical and economic conditions of supplying residential consumers with heat from nuclear power plant

    The reduction of CO2 emission requires technological shift towards carbon-free options. Cogeneration of electricity and heat based on coal and natural gas will experience generation cost increase, if the costs of emissions are imposed on the plant operators. Therefore, nuclear and renewable options should be considered. In this paper, we present the concept of electricity and heat supply system with nuclear condensing turbine adapted...

    Full text to download in external service

  • The Latest Advances in Wireless Communication in Aviation, Wind Turbines and Bridges

    Publication

    - Inventions - Year 2022

    Present-day technologies used in SHM (Structural Health Monitoring) systems in many implementations are based on wireless sensor networks (WSN). In the context of the continuous development of these systems, the costs of the elements that form the monitoring system are decreasing. In this situation, the challenge is to select the optimal number of sensors and the network architecture, depending on the wireless system’s other parameters...

    Full text available to download

  • Centrifugal magnetic fluid seals

    Publication

    Seals perform an important and at times overlooked function in a lubricant system. They prevent or minimize the movement of the lubricant between two surfaces and also minimize the level of contamination in the system. Seals are divided into static and dynamic types. Static seals operate in systems where the mating surfaces do not move relative to each other. In contrast, dynamic seals operate under conditions where the mating surfaces...

    Full text available to download

  • Diagnostic Model of Crankshaft Seals

    Publication

    T he paper presents a research stand being a diagnostic model of radial lip seals used, among others, on crankshafts of piston combustion engines in order to identify the correctness of their operation. The possibility of determining the technical condition of lip seals on the basis of the proposed coefficient of correctness of operation has been described. T he basic features of seals influencing their correctness of...

    Full text available to download

  • NEW DESIGNS OF MAGNETIC FLUID SEALS FOR RECIPROCATING MOTION

    Publication

    T he operating conditions of magnetic fluid seals during reciprocating motion are so different from those observed in rotating motion that the use of their conventional structures for reciprocating motion seals yields no good results. The analysis of the sealing mechanism of magnetic fluid seals in reciprocating motion shows that the operation of these seals is affected by the carry-over phenomenon and magnetic fluid...

    Full text available to download

  • Influence of lubricating oil improvers on performance of crankshaft seals

    Publication

    This paper presents an original method for checking influence of lubricating oil improvers on performance of crankshaft seals of combustion piston engine. Crankshaft seals were tested with the use of a modified friction node of T-02 four- ball apparatus in laboratory conditions. The tests were conducted according to a worked-out algorithm. Their results confirmed usefulness of the method for determining „harmful” performance...

    Full text available to download

  • Mercury concentrations in marine biota with special focus on grey and ringed seals

    Publication

    - Year 2010

    Marine organisms are exposed and sensitive to effects of environmental contamination by heavy metals including different forms of mercury. Baltic seals as the top predators of the marine ecosystem are even more endangered due to (considerable) longevity as well as a long biological half-time of toxin elimination. The concentrations of mercury in seals from the Baltic is poorly known, thus the aim of this work is to determine and...

  • FAILURE OF MAGNETIC FLUID SEALS OPERATING IN WATER: PRELIMINARY CONCLUSIONS

    Publication

    The article analyses properties of magnetic fluid seals installed in rotary sealing no des which operate in the utility water environment. Seals of this type have been examined as a possible solution to the problem with ship manoeuvring propulsion sealing. The present analysis bases on laboratory durability tests of magnetic fluid seals expo sed to long - term utility water loads, at different water pressures and shaft revolutions....

    Full text available to download

  • NEW DESIGNS OF CENTRIFUGAL MAGNETIC FLUID SEALS FOR ROTATING SHAFTS IN MARINE TECHNOLOGY

    Publication

    The centrifugal magnetic fluid seals have important advantage over the conventional centrifugal seals. They maintain very good sealing capacity at static, medium and high speeds of shaft rotation, with the increased seal lifetime, and minimum torque and static friction. These seals are particularly useful in cases when the angular shaft velocity varies and sometimes decreases to nearly or exactly zero, such as in flywheel applications,...

    Full text available to download

  • The Magnetic Fluid Seals Research Results vs. Kelvin-Helmholtz (K-H) instability and Preliminary Conclusions

    Publication

    - Year 2015

    In the article a magnetic-fluid seals durability research and the tests results are presented. The tests were made with three magnetic fluids using various magnets quantity in magnetic assemblies. If values obtained in the repeated test deviated by more than 10 % from results of the first test an additional control test was made for final characteristics. The characteristics are: critical pressure, critical motion velocity and...

    Full text to download in external service

  • Multi-stage magnetic-fluid seals for operating in water - life test procedure, test stand and research results

    Publication

    The edge criteria for magnetic-fluid seals durability research are critical for the seal'stechnological usefulness. The magnetic fluid seal technology in water is much moredifficult technological problem in comparison to gas or vacuum environment. There isalways problem with immediate contact between magnetic fluid and the environmentaluninspected liquids. In the paper are presented ways of experiments definitions carried outwith...

    Full text available to download

  • Performance Characteristics of a Micro-Turbine

    In the paper a design of a multi-stage micro-turbine with partial admission of all the stages is described in detail and the results of particular experimental investigations and numerical calculations are shown, followed by conclusions. The co-generative micro-power plant with the HFE7100 as a working medium was designed and built for experimental investigations. The values of the main cycle parameters were as follows:heat output:...

  • Investigations On Water Circulation in Animal Sea-Water Basins – On the Example of Seals′ Breeding Pools

    Publication

    This paper presents general comments concerning investigations on water circulation in animal breeding pools containing sea water. As an example are given results of computer simulation of water circulation in seals’ breeding pools situated in Marine Station at Hel, belonging to Oceanographic Institute, Gdansk University. A mathematical model of three main pools was prepared with taking into account their inflow and outflow water...

    Full text available to download

  • Topological extraordinary optical transmission

    Publication
    • K. Baskourelos
    • O. Tsilipakos
    • T. Stefański
    • S. F. Galata
    • E. N. Economou
    • M. Kafesaki
    • K. L. Tsakmakidis

    - Physical Review Research - Year 2022

    Τhe incumbent technology for bringing light to the nanoscale, the near-field scanning optical microscope, has notoriously small throughput efficiencies of the order of 10^4-10^5 or less. We report on a broadband, topological, unidirectionally guiding structure, not requiring adiabatic tapering and, in principle, enabling near-perfect (∼100%) optical transmission through an unstructured single arbitrarily subdiffraction slit at...

    Full text available to download

  • Optical transmission of the Niobium thin films

    Open Research Data
    open access

    Niobium thin films with a thickness of 200nm were deposited n a Corning glass substrate by magnetron sputtering method. The optical transmission spectra in a visible light range were.recorded. Investigations showed a good optical transmission thru the layers for each samples, annealed at various temperatures. For measurements samples annealed at 500,...

  • Flow Analysis of a Kaplan Turbine

    Publication

    - Year 2017

    This monograph is a guide to a method of experimental and numerical flow investigations for Kaplan - type turbines. The numerical calculations were compared with the test results of the model Kaplan turbine. The tests were carried out on the model test rig in the Gdańsk University of Technology. The turbine has been thoroughly experimentally investigated, resulting in the identification of optimum setting combination of the stator...

    Full text to download in external service

  • Performance Characteristics of a Micro-turbine, International

    . In the paper a design of a multi-stage micro-turbine with partial admission of all the stages is described in detail and the results of particular experimental investigations and numerical calculations are shown, followed by conclusions. The co-generative micro-power plant with the HFE7100 as a working medium was designed and built for experimental investigations. The values of the main cycle parameters were as follows:- heat...

  • TERMODYNAMIC CALCULATIONS OF TURBINE STEAM PARAMETERS

    In this work a heat balance was made for the nominal conditions of a block working with 18K370 turbine. For the parameters obtained, the thermal-flow calculations of the steam turbine were performed, maintaining the actual geometry of its flow system. Based on the nominal values obtained, iterative thermal and flow calculations were made for both the heat cycle of the power plant block and the steam turbine itself, seeking to obtain...

  • Drivetrain of a Wind Turbine

    In a most commonly met design of a wind turbine the power is transmitted from the rotor to the generator through the system composed of the main shaft, friction connection, multiplying gearbox and a flexible coupling. The driving system comprises almost a complete set of the machine elements being described during machine design lectures and can serve as an interesting illustration...

    Full text to download in external service

  • Mathematical Modelling of Drive System with an Elastic Coupling Based on Formal Analogy between the Transmission Shaft and the Electric Transmission Line

    Publication

    - ENERGIES - Year 2020

    In the paper, the kinematic structure of the transmission shaft between the driving motor and the working mechanism is studied. The analysis is based on electrical and mechanical similarities. The equivalent circuits, typical for electrical systems, are defined for the transmission shaft concerned. Modelling of the transmission shaft based on a formal analogy between the transmission shaft and the electric transmission line is...

    Full text available to download

  • Cooperative Data Transmission in Wireless Vehicular Networks

    Publication

    - Year 2017

    The paper presents issues related to the cooperative transmission in wireless vehicular networks. Cooperative transmission involves the use of mobile terminals as relay stations to improve the transmission quality, improve network performance and reduce energy consumption. The paper presents the methods used to implement cooperative transmission and the types of cooperative networks.

  • [ITiT] Transmission Channel in Radio Communication Systems

    e-Learning Courses
    • S. J. Ambroziak

    {mlang pl} Dyscyplina: informatyka techniczna i telekomunikacja Zajęcia fakultatywne dla doktorantów II roku Prowadzący:  dr hab. inż. Sławomir Ambroziak, prof. PG Liczba godzin: 15 Forma zajęć: wykład {mlang} {mlang en} Discipline: technical informatics and telecommunications Elective course for 2nd-year PhD students Academic teachers: dr hab. inż. Sławomir Ambroziak, prof. PG Total hours of training: 15 teaching hours Course...

  • Transmission parameters of underwater communication channels

    Publication

    The underwater environment is tough and demanding as a communication channel for ultrasonic signals. The channel transmission characteristics in marine and inland waters depend much on local bathymetry and changing weather conditions. The architecture and performance of a reliable underwater acoustic communication (UAC) system should allow real-time adaptation of its transmission parameters to a large variety of possible channel...

    Full text available to download

  • Pressure Pulsations in Turbine Blade Seal

    The paper presents the results of experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type. The performed experimental research proved that in a shroud clearance the pressure pulsates and the effects of the nozzle trailing edge thickness as well as the influence of the rotor blades are observed. The exemplary results...

  • Measurements of transmission properties of Acoustic Communication Channels

    Publication

    Tough transmission properties of shallow water acoustic channels (SWAC) highly limit the use of underwater acoustic communication (UAC) systems. An adaptive matching of modulation and signaling schemes to instantaneous channel conditions is needed for reliabledata communications. This creates, however, unique challenges for designers when compared to radio transmission systems. When communication system elements are in move, the...

    Full text available to download

  • APPLICABILITY OF INLET AIR FOGGING TO MARINE GAS TURBINE

    The dependency of marine gas turbine on the ambient temperature leads to a decrease of the gas turbine power output in arid areas. Very often gas turbine power output demand is high and the power margins originally designed into the driver , has been exhausted. In such circumstances the inlet air fogging is an effective compensation of gas turbine power. In this paper an analysis of inlet air fogging applicability to marine gas...

    Full text available to download

  • Optimisation of turbine shaft heating process under steam turbine run-up conditions

    Publication

    - Archives of Thermodynamics - Year 2020

    An important operational task for thermal turbines during run-up and run-down is to keep the stresses in the structural elements at a right level. This applies not only to their instantaneous values, but also to the impact of them on the engine lifetime. The turbine shaft is a particularly important element. The distribution of stresses depends on geometric characteristics of the shaft and its specific locations. This means a groove manufactured...

    Full text available to download

  • ANALYSIS OF WORKING CONDITIONS OF BEARINGS NO.1 & NO.2 OF TURBINE 13K200 AND DESIGN DEVELOPMENT OF NEW BEARINGS FOR THE TURBINE AFTER RETROFITTING

    Publication

    - Year 2015

    The main goal of the work consisted of preparing an analysis of working conditions of bearings No.1 and No.2 in the existing turbine 13K200, as well as designing geometries of new bearings which would allow for their proper functioning in the turbine following its retrofitting (work under higher load).

  • Secured wired BPL voice transmission system

    Publication

    - Scientific Journal of the Military University of Land Forces - Year 2020

    Designing a secured voice transmission system is not a trivial task. Wired media, thanks to their reliability and resistance to mechanical damage, seem an ideal solution. The BPL (Broadband over Power Line) cable is resistant to electricity stoppage and partial damage of phase conductors, ensuring continuity of transmission in case of an emergency. It seems an appropriate tool for delivering critical data, mostly clear and understandable...

    Full text available to download

  • Design and investigations of a micro-turbine flow part

    -generative micro-power plant with the HFE7100 as a working medium was designed and built for experimental investigations. The heat output of the plant was assumed equal to 20 kW, while the electric output amounted to about 3kW.In the paper a multi-stage micro-turbine with partial admission of all the stages is described in detail and the results of the particular experimental investigations and numerical calculations are shown,...

  • Control of the wind turbine generator

    Publication

    Wind power system consists of two main parts: wind turbine and electrical generator. Wind turbine converts the energy of the flowing air into mechanical energy, next generator converts this energy into electrical energy that is sent to the power system. These two processes should be realized with maximum efficiency and the following requirements for the control system can be formulated: opti-mal wind power conversion, compensation...

  • Advanced Turbine Cycles with Organic Media

    Publication

    Organic Rankine Cycle (ORC) power plants have become very popular and have found their applications in systems with renewable sources of energy. So far their overall efficiencies are not very impressive and only for the upper temperature of about 300 °C do they exceed 20%. A drawback of these cycles is the limitation of the cycle upper temperature due to the heat exchanger technology and the materials used. However, it is possible...

    Full text available to download

  • Dynamic model of nuclear power plant turbine

    The paper presents the dynamic multivariable model of Nuclear Power Plant steam turbine. Nature of the processes occurring in a steam turbine causes a task of modeling it very difficult, especially when this model is intended to be used for on-line optimal process control (model based) over wide range of operating conditions caused by changing power demand. Particular property of developed model is that it enables calculations...

    Full text available to download

  • A multistage turbine for a micro power plant

    This paper presents results of a design analysis of a multi-stage turbine for the cogeneration micro-power plant working in accordance with Organic Rankine Cycle (ORC). The heat power of the plant is assumed equal to 20 kW and the corresponding available electric output is estimated to be of about 3 kW. Different variants of the radial and axial-flow turbines have been considered, while the detailed results of the calculations...

  • INFLUENCE OF INLET GEOMETRY ON THE EFFICIENCY OF 1MW STEAM TURBINE

    Publication

    - Journal of KONES - Year 2019

    The process of the design of the 1MW steam turbine includes designing the stator and rotor blades, the steam turbine inlet and exit, the casing and the rotor. A turbine that operates at rotation speeds other than 3000 rpm requires a gear box and generator with complex electronic software. This paper analyses the efficiency of eight turbine variants, including seven inlet geometries and three stages of stator as well as an eight...

    Full text available to download

  • Proposition of the steam turbine governor structure modification

    Publication

    There is considered the steam turbine governor operation during defense and restoration of the power system. It points out weaknesses of currently used governor structures. The new controller is proposed, that takes advantages of those curently used. The new controller allows for more effective control of the turbine in emergency situations, at frequencies much different from the nominal value.

  • Complex multidisciplinary optimization of turbine blading systems

    Publication

    - ARCHIVES OF MECHANICS - Year 2012

    The paper describes the methods and results of direct optimization of turbine blading systems using a software package Opti_turb. The final shape of the blading is obtained from minimizing the objective function, which is the total energy loss of the stage, including the leaving energy. The current values of the objective function are found from 3D RANS computations (from a code FlowER) of geometries changed during the process...

    Full text available to download

  • Transmission Quality Measurements in DAB+ Broadcast System

    In the age of digital media, delivering broadcast content to customers at an acceptable level of quality is one of the most challenging tasks. The most important factor is the efficient use of available resources, including bandwidth. An appropriate way of managing the digital multiplex is essential for both the economic and technical issues. In this paper we describe transmission quality measurements in the DAB+ broadcast system....

    Full text available to download

  • Organic Supercritical Thermodynamic Cycles with Isothermal Turbine

    Publication

    Organic Rankine cycles (ORC) are quite popular, but the overall efficiencies of these plants are rather very low. Numerous studies have been conducted in many scientific centers and research centers to improve the efficiency of such cycles. The research concerns both the modification of the cycle and the increase in the parameters of the medium at the inlet to the turbine. However, the efficiency of even these modified cycles rarely...

    Full text available to download

  • Application of OFDM technique to underwater acoustic data transmission

    Publication

    Performances of underwater acoustic communication (UAC) digital systems are strongly related to specific transmission properties of the underwater channel. Depending on the characteristics of the channel, an architecture and modulation techniques are usually implemented that are known as reliable solutions for data transmission in difficult radio channels. The OFDM technique seems to be the most promising nowadays. The parameters...

    Full text available to download

  • Problems of Information Transmission

    Journals

    ISSN: 0032-9460 , eISSN: 1608-3253

  • Pressure pulsations in turbine blade seal clearance

    The paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type, while the numerical results were obtained by means of CFD Fluent Code. The performed experimental research and numerical calculations prove that in a shroud clearance the pressure pulsates and the effects of...

  • Research on Quality Requirements of Data Transmission Services in RSMAD

    The paper presents a results and analysis of research of the quality of service requirements (defined by the QoS attributes) for imaging data transmission services using Radio System for Monitoring and Acquisition of Data from Traffic Enforcement Cameras (in short RSMAD). The paper also presents and discusses results of test on the impact of the size of photos from traffic enforcement cameras on the average transmission time. These...

  • Neural Modelling of Steam Turbine Control Stage

    Publication

    The paper describes possibility of steam turbine control stage neural model creation. It is of great importance because wider application of green energy causes severe conditions for control of energy generation systems operation Results of chosen steam turbine of 200 MW power measurements are applied as an example showing way of neural model creation. They serve as training and testing data of such neural model. Relatively simple...

    Full text to download in external service

  • Installation of Compensators in the Power System Transmission Grid

    Publication

    - Acta Energetica - Year 2019

    The article discusses issues of reactive power compensation in transmission grids, with particular focus on the selection of compensator locations and basic parameters. Attention was focused on modern power electronics systems that ensure full automatic compensator adjustment to voltage or power criteria.

    Full text available to download

  • Resonance problems in UHV transmission lines

    The paper presents resonance phenomena observed in 400 kV transmission lines in the Polish power system. Two events are analysed, when shunt reactors used for reactive power compensation, caused overvoltages and overcurrent protection tripping as a result of resonance. An oscillographic fault recordings from protection devices are compared to time domain simulation results. The obtained simulation results match fault recordings,...

    Full text to download in external service

  • Establishment of the Right of Electricity Transmission Easement Through Court Proceedings

    Publication

    - Year 2017

    Including the amendment of the Civil Code Act on May 30, 2008, issues related to the right of easement of transmission were introduced to it. Such a regulation was necessary in view of the need to define the legal status of transmission facilities, existing and designed on real estate property. The purpose of the study is to analyze issues related to the definition of the spatial extent of the law of transmission easement for power...

    Full text to download in external service

  • Determination of Failure Causes of a Steam Turbine Casing

    Publication

    - Solid State Phenomena - Year 2012

    The paper presents results of research and failure analysis undertaken to determine failure causes of a steam turbine casing. After 130,000 hours of service the crack in a outer shell of the turbine casing was found. The inner shell of the casing was made of cast steel grade G21CrMoV5-7, and the outer shell of grade G20CrMo4-5. Following research were performed in order to determine causes of the casing failure: chemical analysis;...

    Full text to download in external service

  • On a Method of Efficiency Increasing in Kaplan Turbine

    This paper presents a method of increasing efficiency in Kaplan-type turbine. The method is based on blade profile optimisation together with modelling the interaction between rotor and stator blades. Loss coefficient was chosen as the optimisation criterion, which is related directly to efficiency. Global optimum was found by means of Genetic Algorithms, and Artificial Neural Networks were utilised for approximations to reduce...

  • Modelling of Nuclear Power Plant Steam Turbine

    The paper describes the approach to a Nuclear Power Plant steam turbine modelling which would enable on-line optimal process control (model based) and diagnosis over wide range of operating conditions caused by changing power demand. Presented model is static, multivariable and nonlinear. Such model enables analyzing the heat cogeneration aspects. Developed model is validated and verified by using archive data gained from researches...

  • Modelling of Nuclear Power Plant Steam Turbine

    The paper describes the approach to a Nuclear Power Plant steam turbine modelling which would enable on-line optimal process control (model based) and diagnosis over wide range of operating conditions caused by changing power demand. Presented model is static, multivariable and nonlinear. Such model enables analyzing the heat cogeneration aspects. Developed model is validated and verified by using archive data gained from researches...

    Full text to download in external service

  • The Impact of Wind Generation on the Transmission System

    Publication

    - Year 2009

    This article has been published to investigate the im-pact of the wind power on the power system- this is a system dependent issue that requires to perform sys-tem specific impact study. This paper discusses the impact of power flow, short circuit current, power quali-ty, voltage stability and the power system during the connection of a wind farm into transmission system. W referacie omówiono wpływ farm wiatrowych na pracę systemu...

  • The Transmission Protocol of Sensor Ad Hoc Networks

    Publication

    - Year 2015

    This paper presents a secure protocol for a radio Ad Hoc sensor network. This network uses the TDMA multiple access method. The transmission rate on the radio channel is 57.6 kbps. The paper presents the construction of frames, types of packets and procedures for the authentication, assignment of time slots available to the node, releasing assigned slots and slots assignment conflict detection.

  • An energetic analysis of a gas turbine with regenerative heating using turbine extraction at intermediate pressure - Brayton cycle advanced according to Szewalski's idea

    Publication

    - ENERGY - Year 2019

    In this paper, a modification of a simple gas turbine into the Brayton cycle with regenerative heating, using turbine extraction at intermediate pressure, is presented. The main concept of the retrofitting is based on the transfer of heat from the turbine exhaust gases to the air entering the combustion chamber. The extracted gas transfers heat to air via the divided regenerative heat exchanger and after that is compressed and...

    Full text to download in external service

  • Multi-stage magnetic-fluid seals for operating in water - life test procedure, test stand and research results. Part II Results of life tests of multi-stage magnetic - fluid seal operating in water

    Publication

    The edge criteria for magnetic-fluid seals durability research were described in previous article [24] and now the tests results are presented. The tests were made with three magnetic fluids using various magnets quantity in magnetic assemblies. If values obtained in the repeated test deviated by more than 10 % from results of the first test an additional control test was made for final characteristics. The characteristics are:...

    Full text available to download

  • The thermal effort during marine steam turbine flooding with water

    Publication

    - AIP Conference Proceedings - Year 2019

    The work discussed an extreme case of cooling a steam turbine. The ship's steam turbine was used as an example. In marine transport units with low-speed engines dominate, however, there are also units with steam turbines. An example of analysed marine steam turbine is shown in Fig. 1. When considering the issue of cooling steam turbines, it is necessary to estimate the extreme conditions that may occur during operation of the turbine....

    Full text available to download

  • ANALYSIS OF THE PROJECT OF INNOVATIVE FLOATING TURBINE

    Publication
    • A. Tomporowski
    • A. Al - Zubiedy
    • J. Flizikowski
    • W. Kruszelnicka
    • P. Bałdowska-Witos
    • J. Rudnicki

    - Polish Maritime Research - Year 2019

    The design of a floating, innovative device for river water aeration and conversion of mechanical energy to electrical energy required the analysis of a number of geometrical and dynamic features. Such an analysis may be carried out on the basis of existing methods of numerical fluid mechanics. Models of pressures, forces and torques characteristic for the conversion of watercourse energy were developed for two basic concepts of...

    Full text available to download

  • [ITiT] Transmission Channel in Radio Communication Systems - 2023/2024

    e-Learning Courses
    • S. J. Ambroziak

    {mlang pl} Dyscyplina: informatyka techniczna i telekomunikacja Zajęcia fakultatywne dla doktorantów II roku Prowadzący:  dr hab. inż. Sławomir Ambroziak, prof. PG Liczba godzin: 15 Forma zajęć: wykład {mlang} {mlang en} Discipline: technical informatics and telecommunications Elective course for 2nd-year PhD students Academic teachers: dr hab. inż. Sławomir Ambroziak, prof. PG Total hours of training: 15 teaching hours Course...

  • The Issues of Reactive Power Compensation in High-voltage Transmission Lines

    This paper discusses the selection of compensation shunt reactors for a double-circuit 400 kV transmission line using the example of the newly built Elk Bis – Alytus transmission line. The analysis takes into account various conditions of the power system. The published results relate to voltage levels in steady states and during switching processes and short circuits.

    Full text available to download

  • Simplified, multiregional fuzzy model of a nuclear power plant steam turbine

    Publication

    Power systems, including steam turbines and synchronous generators, are complex nonlinear systems with parameters varying over time. The paper presents the developed simplified, multiregional fuzzy model of the steam turbine of a nuclear power plant turbine generator set and compares the results with a full nonlinear model and commonly used linear input-output model of a steam turbine. The proposed model consist of series of linear...

    Full text to download in external service

  • Simulation of Signal Propagation Along Fractional-Order Transmission Lines

    Publication

    - Year 2020

    In this paper, the simulation method of signal propagation along fractional-order (FO) transmission lines is presented. Initially, fractional calculus and the model of FO transmission line are introduced. Then, the algorithm allowing for simulation of the nonmonochromatic wave propagation along FO transmission lines is presented. It employs computations in the frequency domain, i.e., an analytical excitation is transformed to the...

    Full text to download in external service

  • Light transmission measurement through the fluidized bed photoreactor

    Open Research Data

    Dataset contains light transmission measurements through the fluidized bed photoreactor. Two sources of light were used: UV-LEDs and UV fluorescent. Measurements were performed at different air flows: 0, 80, 160 and 240 ml/min. The detailed measurement and equipment data was described in measurment info.txt file.

  • MEASUREMENT AND ANALYSIS OF TRANSMISSION LOSSES IN THE SUPPLY SYSTEM OF ELECTRIFIED TRANSPORT

    Publication

    - Journal of Ecological Engineering - Year 2016

    The issue of electric energy saving in public transport is currently becoming a key area of interest, a fact connected with both an increase in society’s environmental awareness and a rise in the prices of fuel and electricity. Electricity can be saved by reducing transmission losses in the supply system. The article presents a method of measurement and analysis of transmission losses in the supply system of electrified public transport...

    Full text available to download

  • Design analysis of Tesla micro-turbine operating on a low-boiling medium

    Publication

    - Polish Maritime Research - Year 2009

    This paper presents results of the design analysis of a Tesla bladeless turbine intended for a co-generating micro-power plantof heat capacity 20 kW, which operates in an organic Rankine cycle on a low-boiling medium. Numerical calculations of flowin several Tesla turbine models were performed for a range of design parameters. Results of investigations exhibit interestingfeatures in the distribution of flow parameters within the...

    Full text available to download

  • Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a UWB Signal

    Publication

    - Year 2010

    This paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. In the first part of paper, unmodified IEEE 802.15.4a IR UWB signal is used. Then some modification of transmitted pulse sequence is proposed, which allow to reduce UWB power spectral density at frequency of narrowband transmission. Finally narrowband transmission quality in presence of modified ultrawideband...

  • Power and energy measurement problems in transmission line between Poland-Lithuania

    Publication

    - Year 2016

    The paper discusses problem of power and energy metering in double circuit overhead transmission line. Considerations are based on example of transmission line connecting Polish substation Bis Elk and Lithuanian substation Alytus.

  • Testing OFDM Transmission Schemes for Shallow Water Acoustic Communications

    Publication

    - Year 2013

    Large variability of communication properties of underwater acoustic channels, and especially strongly varying instantaneous conditions in shallow waters, is a tough challenge for the designers of underwater acoustics communication (UAC system. There is a need for developing adaptive signaling schemes that would dynamically optimize signal parameters in both physical and link layers of communication protocols. The orthogonal frequency...

  • Anisakids of seals found on the southern coast of Baltic Sea

    Publication
    • M. Skrzypczak
    • J. Rokicki
    • I. Pawliczka
    • K. Najda
    • J. Dzido

    - Acta Parasitologica - Year 2014

    Full text to download in external service

  • Parametric Study on a Performance of a Small Counter-Rotating Wind Turbine

    Publication

    - ENERGIES - Year 2020

    A small Counter-Rotating Wind Turbine (CRWT) has been proposed and its performancehas been investigated numerically. Results of a parametric study have been presented in this paper.As parameters, the axial distance between rotors and a tip speed ratio of each rotor have been selected.Performance parameters have been compared with reference to a Single Rotor Wind Turbine (SRWT).Simulations were carried out with Computational Fluids...

    Full text available to download

  • The secure transmission protocol of sensor Ad Hoc network

    The paper presents a secure protocol of radio Ad Hoc sensor network. This network operates based on TDMA multiple access method. Transmission rate on the radio channel is 57.6 kbps. The paper presents the construction of frames, types of packets and procedures for the authentication, assignment of time slots available to the node, releasing assigned slots and slots assignment conflict detection.

    Full text to download in external service

  • OPTIMIZATION OF THE LAST STAGE OF GAS-STEAM TURBINE USING A HYBRID METHOD

    Publication

    - Year 2021

    This paper relates to the CFD calculation of a new turbine type which is in the phase of theoretical analysis, because the working fluid is a mixture of steam and gas generated in wet combustion chamber. At first, this article concentrates on a possibility of streamlining the flow efficiency of a last stage of axial turbine working on gas-steam mixture using a hybrid of the particle swarm optimization algorithm with the Nelder-Mead...

    Full text to download in external service

  • Reduction of Derivative pipeline effort in water turbine

    Publication

    - Studia Geotechnica et Mechanica - Year 2013

    The paper presents an approach to evaluate and reduce the effort of the derivative pipeline in a water turbine of a hydrostatic power station in its vulnerable spots. Potential places of the biggest effort of the structure, as well as the coefficient of displacement and safety factor related to them were identified using FEM numerical method. Pipeline reinforcement was designed and made based on FEM analysis. Original technology...

    Full text available to download

  • Gas Turbine Cycle with External Combustion Chamber for Prosumer and Distributed Energy Systems

    Publication

    The use of various biofuels, usually of relatively small Lower Heating Value (LHV), affects the gas turbine efficiency. The present paper shows that applying the proposed air by-pass system of the combustor at the turbine exit causes tan increase of efficiency of the turbine cycle increased by a few points. This solution appears very promising also in combined gas/steam turbine power plants. The comparison of a turbine set operating...

    Full text available to download

  • Thermal failure of a second rotor stage in heavy duty gas turbine

    Publication

    - ENGINEERING FAILURE ANALYSIS - Year 2020

    The impulse mode of operation and the supply of various types of fuels causes frequent failures even in the heavy duty gas turbines. The paper presents the ravages of second rotor stage failure in a gas turbine. The excessive thermal elongation rise caused by fuel change was indicated as the main cause. We applied nonlinear numerical analysis, preceded by thermodynamic calculations of the turbine and visual inspection of the effects...

    Full text available to download

  • The analysis of turbine propulsion systems in nuclear submarines

    Publication

    The article systematises submarines, which are presently in service, according to their propulsion types (both conventional and nuclear), power output, and submersion depth. Contemporary types of propulsion systems installed and used in submarines are discussed. Calculations were performed for the PWR (Pressurized Water Reactor) type nuclear propulsion system and the supercritical turbine propulsion system (supercritical reactor...

    Full text to download in external service

  • On design and analysis of flow characteristics of the last stage of gas-steam turbine

    Publication

    - Year 2020

    Research regarding blade design and analysis of flow have been conducted for over a century. Meanwhile new concepts and design approaches were created and improved. Advancements in information technologies allowed to introduce computational fluid dynamics (CFD) and computational flow mechanics (CFM). Currently a combination of mentioned methods is used for design of turbine blades. These methods enabled us to improve flow efficiency...

    Full text available to download

  • Dynamic state assessment of the water turbine with the power of 600 kW

    Publication

    - Diagnostyka - Year 2013

    The article discusses the results of experimental studies to assess the dynamic state of the turbine set with the Kaplan turbine. The dynamic assessment was made on the basis of appropriate standards, based on the measurement results of selected parameters of vibration, which have been measured for several states of the machine load. In addition, we attempted to identify the causes of the increased vibration levels based on the...

    Full text available to download

  • 1D Model Callibration on the Basis on 3D calculations for Tesla Turbine

    Publication

    The paper presents the system of equations for axisymmetriclaminar flow, after averaging, through the width of interdisk slit ofTesla turbine. Coefficients were introduced, as a result ofaveraging, that improve the efficiency of 1D model. The minimalnumber of such coefficients was determined. The 1D modelmakes it possible to attain analytical solutions to an accuracylimited by these coefficients. Calibration of 1D model depends...

    Full text available to download

  • Investigation of the aerodynamics of an innovative verticalaxis wind turbine

    Publication

    This paper presents a preliminary three dimensional analysis of the transient aerodynamic phenomena occurring in the innovative modification of classic Savonius wind turbine. An attempt to explain the increased efficiency of the innovative design in comparison with the traditional solution is undertaken. Several vorticity measures such as enstrophy, absolute helicity and the integral of the velocity gradient tensor second invariant...

    Full text available to download

  • Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a UWB Signal

    Publication

    - Year 2011

    This paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. In the first part of paper, unmodified IEEE 802.15.4a IR UWB signal is used. Then some modification of transmitted pulse sequence is proposed, which allow to reduce UWB power spectral density at frequency of narrowbandtransmission. Finally narrowband transmission quality in presence of modified ultrawideband...

  • Damage detection in turbine wind blades by vibration based methods

    Publication

    The paper describes results of numerical simulation for damage localization in the composite coat of a wind turbine blade usingmodal parameters and a modern damage detection method (wavelet transform).

    Full text to download in external service