Wiesław JAŁMUŻNY, Danuta ADAMCZEWSKA, Iwonna BOROWSKA-BANAŚ
Estimating current transformer core characteristics application
Energetyka 2010, nr 12, p. 787
The following paper summarizes the process of elaboration and realization of the individual algorithm for evaluation of magnetization and loss characteristics of ring-shaped ferromagnetic material samples.
Keywords: current transformer, magnetization and loss characteristics, ferromagnetic material
Tomasz SIKORSKI, Edward ZIAJA, Bogusław TERLECKI
Selected aspects of measurement and assessment of wind farms
Energetyka 2010, nr 12, p. 791
Described is the problem of active and reactive power production on a wind farm in various working conditions. Introduced is the theoretical analysis of active and reactive power control capability for 30 MW wind farm equipped with Enercon E70 power generating stations and then it is confronted with real measurement results obtained in the 110 kV point of common coupling with the existing farm. Raised for discussion is a question of a wind farm production flexible share in the context of virtual power stations.
Keywords: wind farms, active and reactive power, assessment of wind farms work
Andrzej BIELACZYC, Stanisław LASOTA, Włodzimierz FENNIG, Robert KIELIAN,
Mariusz LIPIŃSKI
The model of a ring–ball coal mill and the practical use of the coal mill motor power signal and the air-dust mixture temperature signal applied to it
Energetyka 2010, nr 12, p. 797
Described is a simplified model of a ring–ball coal mill and the practical use of signals applied to it: the air-dust mixture temperature signal which was used to identify ignitions in the coal mill and the coal mill motor power signal which was used to identify the loss of fuel in the coal mill that leads to overheating of the mill and then ignition. The identification of these phenomena is particularly important during the coal and biomass co-firing process and may contribute to protection of a coal mill.
Keywords: coal mill, modelling
Antonina KIELECZAWA, Michał BIAŁECKI, Radosław IZAKIEWICZ, Piotr PIETRAS,
Roman SKAKOWSKI, Jacek RUDNICKI
Authorization of an access to operator stations of the Automation System MASTER
Energetyka 2010, nr 12, p. 800
Presented is the next functionality of the automation system MASTER i.e. the authorization of an access to its control realized on the basis of the designed and made out in a modern manner login module. This module enables identification of users, can grant diversified authorizations for individual groups of users, register and report the time of their work. The operating platform for an Automation System MASTER operator station (known also as SCADA ProSter) is the real time system QNX in all of its versions QNX2/QNX4/QNX6. So far, the supplier of QNX system and partner firms have not offered any proprietary software for E-card readers. The login module was realized with the use of ASEDrive reader and E-cards with 2/3 BUS memory protection. Its software consists of two layers: system software for recording and operation of E-cards as well as card reader administrator, and also an application program being a part of the automation system MASTER-ProSter software. The new solution grants independence to both software layers - that is why adaptation of some new equipment will not cause changes in the login module application program requiring only installing of new controllers for a new reader.
Keywords: login module, operator station, system software, application program
Jerzy TRZESZCZYŃSKI
Technical condition assessment and life prediction for the critical components of thermo-mechanical power equipment intended to remain in service beyond 300 000 hours
Energetyka 2010, nr 12, p. 806
The extension of service period of 200 MW power units by about 20 years is connected with fulfillment of the ecological regulations to be effective after the year 2016 as well as with the guarantee of an appropriate service life, especially in the case of critical components of boilers, turbine generators and main steam piping, which is indispensable for both their safe functioning and high availability expected. It's rather frequently accepted, that the genuine and perhaps the only challenge accompanying modernization is the satisfactory arrangement of legal problems in the field of ecology. It is commonly accepted that ensuring the service life of boiler drums, turbine rotors and cylinders and piping in a time horizon of up to 350 000 hours, would cause neither serious technological problems nor high financial outlays. However, the scope of necessary restoration and upgrading work will depend on the condition of separate equipment items being correctly diagnosed with the application of right methods of examination and service life prediction. This paper describes arguments indicating that the assessment of technical condition of the long time operated equipment with particular consideration being given to their further life prediction, requires application of special methodology, covering both the examination and calculations as well as the analysis of service history and conditions. A correct diagnostic approach should cover the preparation for modernization, the modernization itself as well as the following them extended service period, particularly in cases where the latter has been scheduled to exceed 300 000 hours.
Keywords: 200 MW power units, prediction of thermo-mechanical power equipment service life
Alfred ŚLIWA, Paweł GAWRON
Effect of chemical conditions of power units service on a possible extension of their life beyond 300 000 hours
Energetyka 2010, nr 12, p. 813
The power units scheduled to operate for longer than 300 000 hours should not only be modernized but also operated according to proper procedures. Which means that their designed operating parameters shall be strictly observed what is particularly valid as far as chemical and thermal conditions are concerned. Long service life and trouble-free operation of power unit components is conditional, among others, upon the chemical specifications tailor-made for the given power unit. This paper presents application of authors' own experience and recent guidelines by VGB and EPRI in determining the service conditions to be met to ensure good availability of the power units whose service life has been extended.
Keywords: power units, thermo-chemical parameters
Filip KLEPACKI, Dariusz WYWROT
Life of resuperheater coils exposed to the effects of low-emission combustion
Energetyka 2010, nr 12, p. 816
According to recent foreign publications confirmed by our own Polish experience as well, a high percent of a general boiler failure rate is significant to the damage to the coils of superheaters located in the boiler furnace bridge, especially of resuperheater coils generally installed at that area. Despite an overdimensioned wall thickness the life of resuperheater coils is drastically limited due to adverse service conditions, including corrosion causing the reduction in coil wall thickness. The combustion conditions taken previously into consideration in the design of resuperheaters have drastically changed with the advent of low-emission combustion whereby the amount of coils damaged by high-temperature corrosion has markedly increased. This paper describes the cases of damaged resuperheater coils and their diagnostics, followed by the methods proposed to reduce their failure rate owing to which their service life could be extended in "new" operating conditions.
Keywords: resuperheater coils, low-emission combustion
Jerzy DOBOSIEWICZ, Radosław STANEK
Selected damages of blades of the LP part of turbines in conditions of limited flow of the medium
Energetyka 2010, nr 12, p. 821
Presented are conditions in which the edges of final stages' blading get damaged under various circumstances connected with turbine operation and occurring in particular during stationary and transient states, idle running, emergency power drop, operation at reduced output. Having the above in mind the requirements concerning adequate service parameters of power drop and cooling systems of turbine outlet sections are discussed.
Keywords: blades of the LP part of turbines, blades' edges damages occurrence mechanism
Ewald GRZESICZEK, Wojciech MURZYNOWSKI, Radosław STANEK
Selected issues concerning computation analysis of service life of the blading in LP turbine sections
Energetyka 2010, nr 12, p. 824
Material diagnostics is commonly known as a tool used in gaining knowledge on condition of thermo-mechanical power equipment. A comprehensive diagnostics of equipment shall be based on the knowledge gained from the examination performed during equipment standstill as well as on any information that could be attained during its operation. Very often the interpretation of examination results shall be followed by calculation of state of stress in order to interrelate an actual or imminent damage and possible effect of structural features. Presented are selected examples of such procedure being applied in the analysis of blades cracking phenomenon on the final stages of rotors of LP turbine sections.
Keywords: blades of LP turbine section, service life analysis
Krzysztof BADYDA, Janusz LEWANDOWSKI
Prospective utilization of the Polish power industry resources in the light of the EU emission regulations
Energetyka 2010, nr 12, p. 833
If somebody were to indicate the sector of Polish economy differing the most from a corresponding mean European level, the first "victim" would be the power sector, mainly in the domain of power and heat generation due to its dependency upon coal. Given the above it is not surprising that from the very beginning of Poland's accession to the European Union troubles connected with the observance of EU directives have been encountered – mainly in the domain of the environmental impact regulations and still more precisely – with the emissions of combustion products to atmosphere. In the course of accession negotiations Poland was granted some transition periods postponing the deadlines for the implementation of IPPC and LCP directives, but unfortunately we haven't made good use of the opportunity. Poland fails to meet the obligations assumed in this domain and is facing the prospect of financial penalties which may markedly spoil our positive balance of payments with the European Union. No considerable costs, however, were incurred in connection with our adaptation to the presently effective version of the ETS (Emissions Trading Schema) directive. Unfortunately our power sector will be confronted with new challenges. The modified ETC directive will be effective from the year 2013 and three years later in 2016 new IED (Industrial Emissions Directive) will enter into force. This paper presents the current impact of the „emission directives" on the Polish power industry with emphasis being placed on the prospective impact of new directives to be implemented. Within several years to come the configuration of our heat and power generating sector is expected to undergo radical changes. In the extreme case, unless any prohibitive systems are implemented in favour of heat distribution network, hundreds of coal burning cogeneration plants will probably be liquidated after having lost their competitiveness in relation to individual heating.
Keywords: exploitation of the Polish power industry resources, the EU regulations
Stefan POSTRZEDNIK
Biomass - its importance and aspects of utilization
Energetyka 2010, nr 12, p. 840
The dominant source of primary energy is now chemical energy of fossil fuels which we can obtain during the process of combustion, but recently the systematic rise of concern in renewable energy sources has been observed. The source of primary energy can also be biomass i.e. the matter of vegetable origin, formed mainly in the way of photosynthezis. Efficiency of classical and alternative fuels combustion is different, that is why the co-combustion of these fuels is applied. Biomass is usually treated as a fuel harmless to the environment what to some extent results from the fact that the amount of CO2 emitted to the atmosphere during its combustion is equal to the amount of CO2 absorbed by plants reproducing the biomass in the process of photosynthezis. Attention is called to the fact that biomass should not be treated as an alternative fuel only, but in some definite situations as an effective method to remove CO2 from the atmosphere.
Keywords: combustion, biomass, CO2 removal