Ryszard BARTNIK, Anna HNYDIUK-STEFAN, Adam JUSZCZAK
Abandon or modernize the existing coal-fired units? And if so, then with what technologies?
Results of conducted analyses clearly show that the most rational investment strategy concerning electric power generation sources in Poland and, at the same time, guaranteeing national energy security as well as stability, reliability and continuity of power supply, is modernization of the already existing power stations and not building of the new coal-fired power units. Modernization expenditures, even on replacement of boilers and steam turbines with new ones of higher live steam parameters, are relatively small compared with the outlays for new supercritical coal-fired units. In such case, the whole power station infrastructure must be newly built while the already existing one is ready to use and, at worst, it would need only some modernization.
Keywords: coal-fired units, modernization profitability, power units revitalization
Mirosław KIEŁBOŃ
Practical approach to earthing resistance measurement
Presented is the problem of a practical approach to measurements of earthing resistance and grounding cables continuity in selected power objects (MV/LV substations, electricity power poles). The theoretical side of meaurement problems is known but in the measurement practice some of measuring circuits, maintaining required clearances or correct finding of the zero-potential area can be difficult or even impossible to realise. Proposed are some substitute measuring methods that enable obtaining at least approximate measurement results. Conducted are theoretical calculations concerning distribution of a potential around some earthings to estimate proper clearings between measuring electrodes.
Keywords: earthing, electric shock protection, earthing system measurements
Tadeusz Z. CZAJKOWSKI, Marek RUSZCZAK
Prospects for “0+” convection currents commercial application to generate electrical power
Described is a microgenerator – a device acquiring energy from sunlight, wind and convection currents and converting it into electric energy. The capacity of such microgenerator is below 100 watts and it can by definition be used to recharge batteries, feed dedicated devices (monitoring) or emergency lighting and for many more applications.
Keywords: solar energy, wind micro-power plants, wind-sunlight-convection currents synergy
Jacek KARCZEWSKI, Paweł SZUMAN
Operation of a power unit taking part in a power system control – simulation and object testing
Discussed are problems connected with optimization of an operation of a power unit taking part in the process of a power system control. Presented are results of tests performed on a real object (120 MW power unit) and a comparison is made between these results and the simulation ones. Described is also a simulator of a controlled object, designed and constructed in the OTC of Instytut Energetyki, used during testing of a real unit output governor.
Keywords: 120 MW power unit, optimization of a unit operation, simulation and object testing
Maria SADOWSKA
Assessment of a threat caused by emission of harmful substances from organic materials used as decoration and protective coatings of central-heating radiators
The performed studies show clearly that all tested lacquers, which form decoration and protective coatings of central-heating radiators, contained in their chemical composition volatile organic compounds (VOC) that were emitted into the atmosphere. The detected benzene and toluene were probably formed as a result of a micro-pyrolysis occurring during the lacquer layers drying process. VOC concentrations in a reference room atmosphere were lower than the standards established for living quarters and they pose no risk to human health. However, on account of VOCs harmfulness and their possible emission from various sources, one should constantly monitor the levels of these pollutants.
Keywords: volatile organic compounds (VOC), substances harmful to humans, decoration and protective coatings, central-heating radiators
Ewa CHMIEL, Jarosław HERCOG
Assessment of some selected materials applicability in the low-temperature catalytic flue gas denitrification process
Presented are results of laboratory tests concerning evaluation of some selected materials applicability in the low-temperature catalytic flue gas denitrification process. Tests were carried out in a laboratory micro-reactor in the precisely controlled conditions, prepared according to a procedure developed in the Instytut Energetyki, and they involved samples of vanadium catalyst, lignite char and iron-impregnated activated coke. A comparison made between the obtained nitrogen oxide conversion level values in the temperature range of 100o-400oC shows that the proposed iron-impregnated activated coke formula enables achievement of a high NO reduction effectiveness on the level of 84,6% in the temperature of already 250oC.
Keywords: SCR, low-temperature catalyst, activated coke