Materials alternative to natural road aggregates and offered by UTEX company, utilizing the coming from power industry hard coal combustion side products
Energetyka 2010, nr 3, p. 140
Development of the road and highway network increases the consumption of road aggregates coming from natural sources. That increase, in turn, causes considerable rise in their prices. All this, including market competition especially among contractors, compells to look for new solutions in the field of material technologies put into operation. As a result of this, new chances emerge for utilization of alternative materials – like hard coal combustion side products – in the building industry. It makes the come-back to technologies elaborated by prof. Jan Pachowski, from the Road and Bridge Research Institute, in the seventies of the last century. Elaboration and putting into practice the production of such materials and environment-friendly technologies, was a great challenge that could be met by only a few companies dealing with waste management.
Keywords: power industry, combustion waste products, waste utilization
Artur Zając, Marian Madaj
Hard coal combustion side products in mining technologies
Energetyka 2010, nr 3, p. 143
Discussed are the applied by UTEX company methods of maintaining and protection of dog headings. Methods ensuring their traffic functionality consist in wide application of mineral binding materials i.e. the so-called mining binders.
Keywords: hard coal combustion side products, mining binders, waste utilization
Andrzej Ł. Chojnacki, Zbigniew Świerczewski
Costs of losses incurred by distributors of electric energy and caused by unreliability of MV/LV substations
Energetyka 2010, nr 3, p. 149
Presented are results of cost analysis of the losses incurred by electric energy distributors as a result of MV/LV substations equipment damages. Analysed are the failure component costs, given are their characteristics and detailed statistical calculations. Determined are their average values, standard deviations and confidence intervals for the average. The nonparametric verification has also been made. All the analyses have been carried out separately for stations operated in urban and rural networks.
Keywords: reliability, unreliability, transformer substations, urban networks, field networks, unreliability costs
Andrzej Błaszczyk, Adam Papierski, Jerzy Staniszewski, Andrzej Werner
Elimination of the cause of a big power block feed-pump aggregate failure
Energetyka 2010, nr 3, p. 158
Three successive failures of a 380 MW power block main pump aggregate occurred when the power capacity of the block was reduced – the pot pump insert was damaged. After elimination of the pump rotor unit seizing causes, problems with the aggregate start-up occurred. High level of vibrations on the primary and main pump bearings were related to forced induction system resonance, caused by water recirculation on an inlet to the primary pump runner and the first stage runner of the main pump. Discussed is the course of measurements and results of some selected ones, which in turn were the basis to elaborate conclusions and recommendations ensuring further failure-free turbopump operation.
Keywords: power blocks, turbopump failure, failure cause elimination
Artur Lange, Krzysztof Miazga
Application of OS 12-H, OS 19-H and OS 20-H fluxcored wires for welded joints of molybdenum and chromium-molybdenum steels in power industry
Energetyka 2010, nr 3, p. 164
Presented is Outershield 12-, 19- and 20-H fluxcored wires possible application for welded joints of steels used in power industry, with the aim to increase effectiveness of such joints together with cost reduction. Presented are metallographic (macroscopic) examinations of the experimental joints welded with the use of Lincoln Electric fluxcored wires, as well as the cost analysis of such joints compared to the most frequently used methods.
Keywords: welding, fluxcored wires, Cr-Mo steels, welding costs
Sławomir Poskrobko, Jan Łach, Danuta Król
Research of calorimetric properties of some selected industrial wastes and fuels formed from wastes
Energetyka 2010, nr 3, p. 170
Presented are results of calorimetric research of such combustibles like industrial wastes from agriculture and food industry, and fuels formed from industrial wastes. The examined post-production wastes are extracted rapeseed meal (waste from an oil and fat industry) and potato flour post-production solid wastes (from food industry), while fuels formed from wastes are called PAS'r, PAS'i and Ecomat. Fuel properties of coal and biomass composite have also been examined – these substances can be used either as autonomous fuels or co-combusted with conventional fuels in municipal power engineering as well as in power industry. Moreover, experimental values of combustion heat HHV and the calculated on their bases net calorific values LHV, are compared with results obtained by means of selected empirical correlations of relatively big accuracy and based on an element analysis of combustibles.
Keywords: combustion heat, calorific value, industrial wastes, formed fuels