Herbert Leopold GABRYŚ
Polish Power Industry. Preliminary evaluation of 2007 results
Energetyka 2008, nr 1, s. 7
Calculation algorithm of heat exchangers optimum structure adapting a 380 MW power block to combined heat and power generation
Energetyka 2008, nr 1, s. 8
Diminishing of fuel chemical energy consumption and thus reducing emission of harmful combustion products is of a great consequence for the environment. So it is important from ecological, economic and power industry points of view to adapt condensation hard coal-fired power stations for working in a combined system and make use of their abilities to deliver not only electricity, but also heat needed for heating systems, ventilation and air conditioning as well as for preparation of hot utility water.The system has been analysed in Opole Power Station. Presented is mathematical model of the block prepared on the basis of energy and mass balances, non-linear dependences characterizing the installations' work and non-linear equations concerning the state of working medium. Given is calculation algorithm of heat exchangers optimum structure adapting a 380 MW power block to cogeneration work.
On evolution of distribution systems - summary
Energetyka 2008, nr 1, s. 16
The evolution of distribution networks to response to new energy challenges needs a change in paradigms of designing, planning, operation and managing of these sophisticated systems.The new concept of microgrid emerges as a response to deregulation and penetration of a new technologies. These lower-voltage systems are safer and more secure while meeting the demand with highest possible performance.
Adrian HALINKA, Paweł SOWA, Michał SZEWCZYK
Artificial neural networks in decisive circuits of power engineering control systems
Energetyka 2008, nr 1, s. 20
Presented are basic characteristics of power engineering digital control systems integrating functions of identification, measurements, protections and adaptation as well as recognition and location of disturbances occurring in the electricity power industry or in structures separated from it. As a basic tool of data processing and making decisions on various hierarchy levels of control systems, artificial neural networks were applied.
Market effects of electric power companies consolidation
Energetyka 2008, nr 1, s. 26
The change in subjective structure of energy market is a very important effect of restructuring processes and privatization of electric power companies. It is the result of anxiety to strengthen their competitiveness in the being liberalized energy market and especially the electric one. This is a very strong trend, most of all in the UE where the electric energy and gas markets opening process was terminated on the 1st of July, 2007. As a result, among other things, we will be able to choose freely an energy supplier from any of the member countries. The process can be disturbed by big participants which could try to dominate it. In case of the wholesale electric energy market, the market strength of its participants depends first of all on possibility to dominate it by independent power producers (IPP).
Jerzy TOMECZEK, Krzysztof WACŁAWIAK
Modelling of sediment building on boiler superheater convection surfaces and influence of sediments on heat transmission coefficient
Energetyka 2008, nr 1, s. 34
The present-day CFD type calculation programs allow to include the sediment building problem as early as in the designing stage. But the indispensable thing is to use previously elaborated additional procedures describing sediment building. In case of convectional bulkhead superheater modelling results show influence of longitudinal and transverse scales on the amount of sediment. Modelling proved also that lowering the temperature of combustion gases conduces to sediment building. Similar influence, though less intense, has reduction of steam temperature. Considering flow conditions in a multi-pipe system the size of ash grains has substantial influence on sediment shape. Quality of combusted coal, amount and chemical constitution of mineral substance also influences sediment building, while reducing of potassium and sodium contents in fuel reduces building of sediments.
Stanisław KRÓL, Barbara KRÓL, Mirosław PIETRZYK
Correlation between high- and low temperature corrosive wear of waterwall tubes in conditions of low-emission combustion
Energetyka 2008, nr 1, s. 40
Presented is influence of chlorine and sulphur on 360 MW power unit com- bustion chamber construction elements. Investigations show that applying NOx emission reducing burners causes activation of waterwall tubes cor- rosion in burner zone. Sulphur occurring in combustion gases diffuses into the scale but being concentrated mainly in hematite it influences the process, reducing protective properties of the sublayer. Local chlorine concentration increase, inconsiderable in sediments and product but very high on grain boundaries, activates intensively corrosion of these areas.
Krzysztof WOJAS, Adam SZYMAŁA, Jan PENAR
Indirect (data-based) operation control methods - purposes, theoretical bases, problem of calculation uncertainty, possibilities in the scope of installations power analysis
Energetyka 2008, nr 1, s. 46
In the recent years areas where data-based operation control methods are used have changed significantly. Considering the compulsory legal requirements concerning CO2 emission monitoring and reckoning "green" and "red" energy, the importance of control, auxiliary and emergency methods as the indirect ones increased significantly. Having at disposal an access to rich basis of precise measurements and knowledge possessed by Operation Control Services in the range of methods and calculation algorithms applied as well as experience and the know-how of operation conditionings, it allows for the wide application of indirect operation control methods leading to efficiency improvement and reduction of installation operating costs.
Józef PASKA, Tomasz SURMA, Mariusz SAŁEK
Electricity generation from renewable energy sources in the UE
Energetyka 2008, nr 1, s. 51
Using of renewable energy sources is one of the essential components of balanced development, bringing calculable economic, ecological and social effects. Developed countries notice the necessity to reduce emission of energy fuels combustion products as well as the necessity to seek alternative energy sources. So, supporting the development of using renewable energy sources becomes the more and more important challenge for almost all countries in the world. In the European Union it has a very substantial position not only in political declarations but also in the being realized executory programmes. Discussed is the present state and perspectives of electricity generation from renewable sources in the UE.
Leszek WOJDANOWICZ, Marian MACIEJKO
Investigations on method of GAVO impeller corrosion protection - on the example of IOS in Łaziska Power Station
Energetyka 2008, nr 1, s. 65
Discussed are reasons and results of quickly advancing corrosion and erosion processes of rotary heat exchangers working in combustion gases desulphurization installations (IOS). Presented is valuation of selected substitute materials usefulness for impeller construction elements. Prepared is efficiency estimation of the selected correction preparation and the method to introduce it into the inside of an impeller. Given are exemplary results of combustion gases and sediments chemical constitution investigations as well as gravimetric investigations of materials.
Buchholz type protection in power transformers - necessity of routine testing
Energetyka 2008, nr 1, s. 71
Described is the way in which the protection functions as well as types of damages against which it protects a transformer during operation. Presented is general estimation of situation concerning protections used in power industry. Mentioned are essential problems and given are guiding rules referring to replacement, assemblying and testing of protections.
Mariusz STOLARSKI, Stefan SZCZUKOWSKI, Józef TWORKOWSKI
Biofuels obtained from energetic perennials biomass
Energetyka 2008, nr 1, s. 77
Investigated was fresh biomass obtained in two crop terms from selected spe- cies of energetic perennials. Analysed were species giving biomass in form of wood: common ozier (Salix viminalis) - sub-species Sprint and Wodtur (annual sprouts) and rambler rose (Rosa multiflora); species giving semi-lignified biomass: rose mallow (Malvaceae), topinambur (Helianthus tuberosus), cup plant (Silphium perfoliatum L.), giant knotweed (Reynoutria sachalinensis) and Japanese knotweed (Reynoutria japonica) as well as species giving strawy biomass like three sub-species of miscanthus (Miscanthus sinensis, Miscanthus giganteus, Miscanthus sacchariflorus) and prairie cordgrass (Spartina pectinata). The plants were harvested in November 2005 and March 2006. Humidity, ash contents, heat of combustion, calorific value and elementary chemical constitution (carbon, hydrogen, sulphur) were determined in the collected biomass.