Grzegorz BŁAJSZCZAK, Artur DZIUBA, Andrzej DOBROCZEK
Hardware standards required in connecting large systems used for monitoring of electric energy quality
Energetyka 2010, nr 7, p. 401
Electric energy quality monitoring systems are progresssively applied at all voltage levels and consist of various appliances produced by various manufacturers. Implementing of certain standards will enable easy future development and exchange of information with owners of other systems, as well as will ensure reliability of transferred information. Presented are selected technical requirements used in building of nation-wide system for monitoring of electric energy quality in a transmission network.
Keywords: energy quality, monitoring, data transmission, standards, hardware requirements
Andrzej Ł. CHOJNACKI, Zbigniew ŚWIERCZEWSKI
Costs of unreliability of MV/LV transformer-distribution stations operated in municipal and rural electric networks
Energetyka 2010, nr 7, p. 406
Presented are analysis results of costs of losses suffered by consumers and electric energy distributors, ensuing from failures of the equipment working in MV/LV transformer-distribution stations. Cost average values, standard aberrations and confidence intervals are calculated. There is also made a nonparametric verification. Analyses are caried out separately for stations operated in municipal and rural networks. All calculations are based on empiric data collected during 10 years of operating a station localized in the area of a big, domestic power plant.
Keywords: reliability, failure frequency, transformer substations, municipal networks, rural networks, costs of unreliability
Jerzy DOBOSIEWICZ, Ewa ZBROIŃSKA-SZCZECHURA
Selection of materials for tube inserts in heat exchangers
Energetyka 2010, nr 7, p. 412
Material of tube inserts for heat exchangers has a substantial influence on effectiveness of work and its reliability, particularly on the process of heat transfer. That is why all decisions concerning material selection should be supported by technical and economic analysis. Presented is a survey of groups of materials applied for heat exchanger tubes and factors influencing their durability. Most of heat exchanger tubes damages are caused by erosion-corrosion processes and vibrations.
Keywords: heat exchanger tubes, corrosion processes, material selection
Jerzy DOBOSIEWICZ, Ewa ZBROIŃSKA-SZCZECHURA
Durability of martensitic steel pipeline welds
Energetyka 2010, nr 7, p. 415
The work of martensitic steels in creeping conditions, and especially of their welds, creates many problems, most of which concerns type IV circumferential cracks. Welded joints are the cause of many damages after only about 50 000 hours of work, no matter who the performer of welds is nor what kind of additional materials are used. That type of damages are the factor having substantial influence on reliability of modern power installations. To know the mechanism of crack occurrence causes is essential for limiting the amount of damages. Discussed are the most probable causes of their origination as well as changes occurring in metal structure, especially in welds, after several dozen thousand working hours.
Keywords: martensitic steel, welded joint damages, weld cracks
Paweł GAWRON
Standards and guiding rules concerning quality of circulating agent in water/steam systems of electric power and CHP plants. Present legal status
Energetyka 2010, nr 7, p. 419
The latest issues of guiding rules concerning quality of circulating agents in water/steam systems of VGB and EPRI electric power and CHP plants introduce new, numerous changes in the way of approach to the problem of making corrections and proper control of circulation. The Polish standard PN-EN 12952-12:2006 is directed to contractors rather than to users, indicating minimum requirements concerning quality parameters that must be kept for a safe (not necessarily optimum) work of power installations.
Keywords: water/steam system, Polish standard PN-EN 12952-12:2006, VGB guiding rules, EPRI guiding rules
Tomasz SŁUPIK, Jan PENAR
Power audit as an element supporting effective generation and utilization of energy
Energetyka 2010, nr 7, p. 429
Efficient improvement of energy generation, transmission or utilization effectiveness needs some knowledge and awareness of the pro-effective operations potential in a given company. Mentioned are essential aspects of a power audit – a diagnostic tool for efficient identification of that potential. On the basis of the authors' experience gained during relization of audit works grounded on measurements carried out for power industry, distribution networks and other kinds of industry, discussed are essential problems accompanying the carrying out of energy efficiency audits.
Keywords: power audit, power efficiency
Robert WITEK
Investment supervision over operations in the scope of power efficiency
Energetyka 2010, nr 7, p. 432
Presented is an outline of the most important processes and operations that should be realized within the frames of carrying on the investment supervision over tasks and investment projects in the material range consistent with provisions of the Energy Efficiency Act.
Keywords: Energy Effciency Act, investment supervision
Roman KOŁODZIEJ
Measurements accompanying an energy efficiency audit
Energetyka 2010, nr 7, p. 435
Presented is the audit activity area connected with a power audit supporting element in the form of additional measurements carried on installations and technical appliances in power industry and other industries. Special attention is paid to measurements of thermal capacity of installations and appliances of main technological lines as well as installations supporting main production processes.
Keywords: power audit, measurements of thermal capacity parameters
Mateusz KASPRZYK
Improvement of technical and economic indicators: operating reserves in cooling systems
Energetyka 2010, nr 7, p. 438
Presented are possibilities to improve technical and economic indicators by optimum running and control of a cooling system For a turbine-generator set it is vital that one should strive for obtaining vacuum as close to the optimum one as it is possible. Adjusting the cooling water temperature, changing the operating efficiency of cooling fans or cooling water pumps, you can additionally generate considerable savings by limiting auxiliaries energy consumption.
Keywords: control, cooling systems
Jacek LEPICH
Operating reserves in industrial fan systems
Energetyka 2010, nr 7, p. 442
Discussed are basic aspects of possibility to improve energy efficiency in industrial fan systems. Presented are exemplary results of investigations and analyses of fans operated in power installations in respect of proper selection for the needs of a system and operating in an adequate load range. Mentioned are also examples of effect analysis of the at present operated fans and motors replacement with the more energy saving ones, including profitability analysis of such operations.
Keywords: enegy efficiency, industrial fan systems
Tomasz SŁUPIK, Andrzej DRAJCZYK
Operating reserves in pumping systems
Energetyka 2010, nr 7, p. 446
Indicated are basic areas of energy losses generation in pumping systems. Presented are conclusions drawn from analysis of possibility to adapt an existing pumping system to requirements of work in conditions of changing operating efficiency. Given are effects resulting from application of various pump control solutions – by thyristor cascade, inverter or by machining the pump rotor.
Keywords: pumping systems, energy losses
Piotr PLIS
Improvement of thermal processes with the use of egzergy losses analysis
Energetyka 2010, nr 7, p. 450
Explicated is the notion of egzergy and presented are exemplary methods of its balancing in flow systems met in power industry. Given are two short calculation examples for which the process egzergy efficiency is reckoned. Attention is paid to usefulness of egzergy analysis application in industrial practice. Indicated are possibilities of egzergy anaylysis application to improve processes with the aim to obtain an expected energy effect.
Keywords: egzergy, egzergy analysis
Dawid KIJOWSKI
Fuel financial settlement as an element of a periodical generation control
Energetyka 2010, nr 7, p. 453
Discussed are problems connected with methodology of calculating the amount of consumed fuel in electric power plants or in CHP plants with the use of direct methods, also with determination of their accuracy, and reckoning the acceptable divergence level between them.
Keywords: fuel financial settlement, direct methods
Piotr BURMISTRZ, Krzysztof KOGUT
Reliability of monitoring coal dioxide emission coming from the fuels combustion process
Energetyka 2010, nr 7, p. 457
Described are the most often applied methods used for determining parameters submitted to monitoring within the frames of European Union Emission Trading System (EU ETS) with reference to fuels. Given is a method of the calculated and measured parameters uncertainty assessment for the described methodologies. On the basis of data coming from industry installations combusting hard coal, natural gas, coke-oven gas and blast-furnace gas, an analysis is made of the influence of fuel sampling frequency on quantity of the reported data uncertainty.
Keywords: fuel combustion, CO2 emission, emission monitoring