Józef PASKA
Distributed generation with the application of hybrid generation systems
Presented is a synthetic overview of problems connected with hybrid power systems as a method to integrate various technologies of electric energy generation and to develop distributed generation. Discussed is the definition of a hybrid system, system types, utilization of electricity storage systems and exemplary solutions. When observing the quick development of distributed generation one could think that electropower system will evolve into the form in which the ways of electric energy (and/or heat) transmission are the possible shortest ones, unnecessary power processes will be eliminated and all available energy forms and carriers (e.g. renewable and distributed resources, waste energy etc.) will be managed. The method for effective utilization of renewable and distributed primary energy resources are hybrid generation systems in which integration and synergy of various electric energy generation technologies enable meeting of power demand of individual end-users or local communities. Building of hybrid generation systems of medium and high output power utilizing renewable and distributed primary energy resources located close to consumers will enable avoiding of a part of transmission and distribution costs. Such type systems are of considerable importance to environment protection as many of utilized sources do not emit any pollutants. Hybrid generation systems create also possibility to generate heat in the way of separated or combined production. The mentioned possibilities exist in case of application in HSW such technologies like piston and Stirling engines, small and micro gas turbines, medium and high temperature fuel cells, heliothermal power plants, biomass and biogas utilization and utilization of geothermal heat.
Keywords: distributed generation, hybrid generation systems, electric energy generation, sustainable development
Marcin TROJAN, Dawid TALER
Method for ash fouling assessment of a steam boiler superheater
Presented method of superheater modelling can be applied for designing and operation of steam boilers. The price of alloy steels is high so it results in the need of building the individual superheater stages of various kinds of steel, adapted to the maximum temperature of tube walls that you can find in the given superheater stage. The proposed method enables determining of a precise temperature pattern of tube walls along the flue gas path and it can be applied for calculations concerning horizontal and pendant superheaters in subcritical and supercritical boilers. The mathematical model of a superheater with ash fouled tubes can be applied in boiler operation monitoring systems for indirect assessment of a superheater ash fouling degree.
Keywords: power boilers, superheater fouling, mathematical assessment method
Daniel MASYK, Patrycja ŻUPA
Comparison of contract awarding procedures for tenders conducted by awarding sector entities – open tendering or negotiated procedure with publication?
One of the dilemmas the awarding entity must confront when making decision concerning conducting of contract award procedures is selection of the procedure itself. The current practice shows that awarding sector entities practically do not apply procedure to award contracts by restricted tendering, using only the procedures to award contracts by open tendering or negotiated procedure with publication. When comparing statutory deadlines for the open tendering and the negotiated procedure with publication, we can see that the open tendering is obviously a faster procedure than the negotiations with publication, however, it is the negotiated procedure with publication that allows the awarding entity to make more precise description of the object of the contract or the terms and conditions of the contract.
Keywords: contract award procedure, awarding sector entities, comparison of open tendering procedure and negotiated procedure with publication
Adrian PRUSKO
Importance of an acoustic background in environment noise measurements and in the assessment of obtained results
Acoustic background is a noise that occurs in a specific place of measurement after switching off the investigated noise source. The idea of a background noise and connected with it measurement methods concern all kinds of noise measurement: in an environment, in people’s accomodations, of individual devices or even of workstations. The attention is fixed on problems connected with determination of an acoustic background level and its influence on the assessment possibility of the carried out guarantee or commissiong measurement results of the noise emitted to the environment.
Keywords: noise measurements, acoustic background, background level determination, assessment of the results of a noise guarantee measurements
Jolanta TROJANOWSKA, Antoni LITWINOWICZ
Possibility of heavy metal precipitation on various sludge treatment stages of a wet flue gas desulfurization process
Sludge produced in electric power plants as the result of functioning of big wet flue gas desulfurization installations are characterized, among the others, by high content of chlorides and sulfates, the presence of heavy metals and of suspended solids, mainly of gypsum. An attempt is made to assess the possibility of precipitation of selected heavy metal ions in the form of hydroxides or sulfides forming during the sludge treatment as the result of adding milk of lime or TMT 15. In connection with the possibility of precipitation of sparingly soluble carbonates of heavy metals, there were made adequate calculations also for carbonates. It was carried out in the form of two options: with and without taking into consideration the influence of a solution ionic strength on sediment solubility. Proved is, that in solutions with such high salinity like sludges coming from the wet flue gas desulfurization, the influence of ionic strength is essential. But precipitation of some heavy metal iones to the level acceptable by the NDW regulations, in the framework of typical parameters of an alkaline precipitation centre, may be impossible to achieve.
Keywords: sludge treatment, wet flue gas desulfurization installations, assessment of heavy metal ions precipitation possibility
Sonia JAREMA-SUCHOROWSKA
Hazards for the management of gypsum coming from flue gas desulfurization installations
Post-reaction gypsum produced in power industry flue gas desulfurization installations with the use of wet lime and gypsum method, is a raw material of full value with properties close to natural gypsum. The main hazards for the post-reaction gypsum management result from the growing amount of gypsum that cannot be currently utilized. However, the post-reaction gypsum meeting technical and environmental requirements but not finding purchasers, should not be treated as a waste but stored at stockyards as the product for future utilization. Presented are the most important problems and hazards connected with the post-reaction gypsum management.
Keywords: flue gas desulfurization installations, post-reaction gypsum, gypsum management and its hazards
Kazimierz ZAMOROWSKI
Aspects of the national power industry adaptation to nitric oxides emission standards – influence of applied technologies on boiler operation and on costs of flue gas denitrification
Adaptation of the national power industry to the requirements of the new and more strict nitric oxides emission standards coming into force from the year 2016 is connected with many aspects. Described are here the basic problems relating to application of far-reaching reduction of nitric oxides in power boilers. Discussed is the influence of flue gas denitrification on boiler operation. Attention is turned to positive and negative effects of the applied methods. Presented is the projection of investment and operating costs on the example of the type OP-650 boilers.
Keywords: power boilers, nitric oxides emission reduction, flue gas denitrification methods
Jerzy TRZESZCZYŃSKI, Radosław STANEK
Management of power boiler technical condition maintaining based on the risk analysis
Leakages of a power boiler heating surface tubes influence to the highest degree the power units availability. Many factors can contribute to damage probability - their importance and extent may vary for each individual boiler, being additionally subject to changes over time. If such informations could be associated with damage consequences in the form of overhaul costs and especially the rate of production loss, then the management of power boiler heating surfaces maintaining based on the risk analysis would be possible.
Keywords: power unit availability, leakages of a power boiler heating surface tubes, risk analysis
Jerzy TRZESZCZYŃSKI, Radosław STANEK
Failure frequency analysis of a 200 MW power unit critical elements as an important component of a service life prediction methodology
The longer is exploited the equipment, the more useful are damage statistics because they make easier the elaboration of the investigation scope, results interpretation, formulation of technical condition assessment and service life prediction. The statistics quality depends on the amount of data and correctness of damage reasons determination. Described is an approach that ensures meeting these both conditions for critical elements of the long-operated 200 MW power units.
Keywords: equipment service life prediction methodology, failure frequency analysis of power units critical elements
Jacek MALKO
Japan energy sector. Radical transformation - to what extent?
Japan government, in its willingness to overcome the power crisis, is seeking ways to ease environment influence assessment procedures with the aim to facilitate building of coal fired power plants. It is expected that the plans concerning building of such plants, as the alternative to nuclear ones, will get approval in the next year. Big hopes are tied to the improvement of energy efficiency that should minimize the electric energy supply limitations, the first signs of which occurred during the last hot and damp summer. Moreover, the government introduced the law obliging the ten biggest electric power firms to buy energy generated from renewable sources from private producers with an application of the guaranteed prices system.
Keywords: Japan energy sector, transformation of national power industry, nuclear or coal-based power industry