Herbert Leopold GABRYŚ
Electropower industry 2006. First months - different?
In the first four months of the present year the electric energy consumption amounted to 53,4 TWh which is 5,5% more than in a comparable period of the last year. Also the end of 2005 tendency to reduce the import and increase the export was kept. The results obtained by Polish electropower industry subjects in the first months of 2006 - considering from energy balance - are a good prognosis for their final financial outcome.
Jan SZARGUT, Wojciech STANEK
Pro-ecological VAT and its influence on the consumption of non-renewable primary energy carriers
Instead of the existing VAT, which does not result from any objective criterion, a new proecological VAT proportional to the cumulative exergy consumption of non-renewable natural resorurces, burdenig all the production steps of the considered product has been suggested. The new VAT would be transmitted to the state office only by the plants extractig raw materials from domestic natural resources or importing the products or raw materials. The reimbursement of VAT would concern only the exported products. Exemplary calculation of the increase of market price of energy carriers has been included.
POWER INDUSTRY INSTITUTE BULLETIN
Marek POWROŹNIK
Reducing light flickering in island power systems
In power systems based on generators with so-called light shafts driven by slow-speed Diesel engines can occur voltage disturbances in the form of alternating-current components of frequencies from a few to almost twenty Hz and with a considerable big relative amplitude caused by a non-uniform motor-generator rotational speed. The presence of these slightly perceptible disturbances in voltage feeding lighting systems causes negative effects both for man's health and his comfort and for mains receivers. Presented are ways in which the phenomenon can be measured and evaluated and discussed is the method to reduce the disturbances by using an additional dynamic correction of generator exciting current.
The measurements were performed in Samos Island (Greece) power system.
Sławomir KAKIETEK, Jerzy SZYMCZAK, Krzysztof JAGIEŁŁO
In this work the methodology of determination the risk of slagging of pulverized fired boilers on the basis of neural networks and expert system was shown
The SLAGANN software was created. The method was tested against measurement data taken at real utility boiler OP-650 during combustion and co-combustion of coal with biomass. Results show that SLAGANN is a reasonable diagnostic tool which can be an advisory program for power plant's staff. In order to improve the quality of program predictions there is a need for additional investigations to collect data essential for learning or using investigations results of different research centres which can increase not only the diagnostic performance but also its research applicability.
POWER INDUSTRY AKADEMY
Stanisław CADER, Bogumił DUDEK, Roman FOBER, Tadeusz GONTARZ, Witold WIŚNIEWSKI
7th session - Live line works carried out on electrtical power engineering units and installations - Eigth lecture - Shunting of up to 1 kV power circuits
PRO NOVUM BIULLETIN
Jerzy DOBOSIEWICZ
Influence of feed and boiler water quality on durability of generator heating surfaces
Heating surfaces of a boiler with natural circulation are often covered with corrosion products and sediments. It may cause leaks because pipes walls become thinner or get overheated. The problem mostly concerns evaporator pipes and superheater coils. In the paper stated is that: during operation of installations water properties and working conditions should not be often changed; sediments chemical constitution is different, soluble particles can be washed out from sediments during outageing or starting the boiler, sediment quantity and and its chemical constitution is often changed in the area close to leakage; corrosion products are often mixed with sediments especially in superheaters subject to standstill corrosion; there is a need of checking the quality of water, steam and condensates in transient state.
Filip KLEPACKI
Influence of stress and fatigue corrosion on boiler failure frequency
The effect of stress corrosion cracking takes place only when three conditions are fulfilled simultaneously: excess stress close to yield point, aggressive medium and metal with numerous impurities on grain boundaries. The problem how a stress corrosion crack occurs has not been well investigated yet, so all hitherto existing explanations are of speculative character only. Moreover, the influence of stress applied, aggressive medium and the type of material used on destruction process has not been quantitatively determined either
Alfred ŚLIWA, Paweł GAWRON
Influence of boiler water purity on pipe damages in areas with numerous narrowings, in pipe bends and inclined sections of piping
Basic conditions having influence on boiler tubes durability are: proper constructional solutions, proper assembly (gas and electric welds), tube bends in furnace chamber of possible big radius, not operating the boiler below boiler ratio safety level, keeping adequate quality parameters of feed and boiler water, not allowing violent changes in boiler ratio and boiler pressure which can cause cicrculation disturbances.
POWER ENGINEERING AND ECOLOGY
Włodzimierz KOTOWSKI, Eduard KONOPKA
Wood biomass - its place in the process of acquiring energy from renewable resources
Biomass is easily converted into solid, liquid and gas fuels. Four technologies of biomass converting are known and applied in the world: combustion, gasification, pyrolysis and liquefaction. In the paper discussed are pyrolisis and combustion - mainly of wood - but also of straw and sludge.
Presented is an effective method of hydrogen generation from renewable and containing big amount of water energy carriers.
Jacek KALINA, Janusz SKOREK
Technical conditions concerning building of power systems integrated with thermal biomass gasification