Andrzej FIRLIT, Grzegorz BŁAJSZCZAK
Tools for evaluation and analysis of electrical energy quality
Energetyka 2009, nr 12, p. 787
Discussed are tools for electrical energy quality evaluation. Ascertained is that PQView environment can be used for long-term, continuous analysis of electrical energy quality parameters. Certified is possibility of PQView cooperation with various monitoring systems, like ENCORE Series System elaborated by Dranetz or Qualitrol Quality Information System (QIS of Version (min.)3.5).
Keywords: electrical energy quality, measurement of voltage and current, PQView programs
Piotr OLSZOWIEC
New criteria for assessment of DC circuits insulation resistance level. What should signal the DC network insulation monitors? – debate article
Energetyka 2009, nr 12, p. 794
Discussed are new criteria for proper assessment of DC auxiliary circuits insulation resistance level. Described are methods of their practical implementation. Presented are possible threats to reliable operation of relays due to insulation deterioration.
Keywords: DC auxiliary circuits, insulation, insulation condition
Waldemar DOŁĘGA
The role of distribution system operators in view of the being in force law regulations and in the aspect of national energy security
Energetyka 2009, nr 12, p. 800
Presented is analysis and evaluation of possibilities and effectiveness of the hitherto obligatory law regulations concerning distribution system operators, with the aim to ensure energy security and realized in the frames of PBZ-MEiN-1/2/2006 "National energy security" research project, ordered by Consortium of Gdańsk, Silesia, Warsaw and Wrocław Universities of Technology. Law regulations referring to national energy security and comprised in the Energy Law Act are of multiplane character and concern, among other things, distribution system operators. Presented is analysis and evaluation of law regulations, obligatory for such operators, in the aspect of national energy security. Proposed are legislative solutions to improve the existing state of law.
Keywords: power system, energy security, law, electrical energy market
Zbigniew Ekalt , Dariusz Ptak , Kazimierz Ruszniak
Heat exchange equipment after 30 – 50 year operation
Energetyka 2009, nr 12, p. 813
Many years of experience gained during the repairs of such equipment have made it possible to specify some common features characteristic of long operated heat exchangers. Following this, one could try to classify the objectives and scope of further reconstruction or repair. This paper makes an attempt to systematize the relevant knowledge in this field. All types of heat exchangers installed within the power unit will be classified and presented basing on specific examples. Such a work can be helpful to the specialists in formulating detailed scope of works and requirements for tenders.
Keywords: power blocks, heat exchangers, repairs
Alfred Śliwa, Paweł Gawron
Chemical cleaning of boilers. The technologies applied and recommended by Pro Novum
Energetyka 2009, nr 12, p. 821
A problem of an incomplete removal of operating deposits, including copper compounds, from the inside surfaces of the tubes of boiler after its chemical cleaning has been reported in recent years by a few power plants. It was detected on the basis of tests performed on the parts of tubes sampled just after their chemical cleaning. The paper presents the technologies of chemical cleaning of highpressure boilers which are applied and recommended by Pro Novum on the basis of its own, long standing experience. One of the technologies is based on a concentrated solution of hydro-chloric acid whereas the second one, ecologically oriented method consists in cyclic, repeated cleaning of the boiler using complex compounds.
Keywords: electric power stations, steam boilers, technologies for chemical cleaning of boilers
Jerzy Dobosiewicz, Ewa Zbroińska-Szczechura
Recommendations for the assessment of welds and elbows in piping and headers operated in creep conditions
Energetyka 2009, nr 12, p. 825
The residual life period of butt welded joints is generally shorter in comparison with that of the other parts of headers and piping, whereby circumferential cracks often appear in finegrained area of heat affected zone of the welded joints just after more than 100 000 hours in service. Following the results of both destructive and nondestructive testing it was found that the cracks were caused directly by changes in metal structure accompanied by supplementary external stresses usually generated by bending. The cracks appear on the external surfaces and are easily detectable by nondestructive methods such as magneticparticle inspection or metallographic replication.
Keywords: piping, circumferential cracks, testing methods
Jerzy Trzeszczyński
Monitoring of thermal-and-mechanical equipment in power plants as a vital factor in predicting their life during the final phase of an extended service period
Energetyka 2009, nr 12, p. 831
The prediction of life of the power equipment operated both at creep temperatures and at lower ones has always been subjected to a considerable error. Many components were overdimensioned because of very conservative safety factors applied in their strength calculations whereby even serious errors in calculations have created no real hazard for safe operation of the power equipment. However, if we assume that a part of the equipment was to operate for a very long time then the components with total operating period exceeding 300 000 hours shall be specifically tested and assessed and, moreover, their operating conditions shall be systematically analysed. The proposal of such an approach was presented for selected critical components of 215 MW/235 MW power units.
Keywords: electric power stations, thermal-and-mechanical equipment, monitoring of equipment work
Filip Klepacki
Characteristics of copper steel in the boiler drum long time in service
Energetyka 2009, nr 12, p. 833
The paper presents the results of destructive testing of 17CuNi4 steel (accordingly to German Standard DIN) gained for a drum of boiler operated for about 320 000 hours. The scope of testing included: Metallographic examination, Static tensile test at 24°C and 350°C, Impact test, Analysis of chemical composition of steel, Hardness measurement. The tests were performed in various areas with a differentiated degree of material effort. To illustrate the degree of material effort in those areas supplementary calculations have been made using finite element method. The conclusions were positive to state that the steel from that particular boiler drum has met not only the standard specific values but also the general requirements established for boiler drum steels. No results of initial tests of the element were available, however it is possible to state that the present steel structure is close to the initial one. The above results are of particular importance, having in mind that they were obtained on copper steel generally found susceptible to damage by brittle fracture and showing poor reliability, particularly in case of long time operation.
Keywords: boiler drums, boiler drum copper steel, testing methods
Maciej ZAREMBA
"ENERGOPROJEKT–KATOWICE" S.A. – 60 years of co-creatingof the Polish power industry
Energetyka 2009, nr 12, p. 839
"ENERGOPROJEKT–KATOWICE" S.A. is a leading design and consulting bureau in the Mid-Eastern Europe. The main range of its activitity comprises studium works and technical documentation for the power sector. EPK S.A. offers also preparing of elaborations for mining, chemical, metallurgic and food industries as well as for subjects connected with municipal economy. EPK S.A. cooperates with the biggest power sector companies all over the world. Described are the greatest achievements of the firm during 60 years of its history.
Keywords: „ENERGOPROJEKT-KATOWICE" S.A. – 60 years of the Company history
Bożena BORYCKA
Ecological advantages of fruit and vegetable wastes biomass combustion
Energetyka 2009, nr 12, p. 847
Described are investigations on usability of such biomass source like fruit and vegetable industry wastes as the "ecologically clear" renewable source. Calculated emissions of sulfur dioxide and dust, as indicators of a fuel ecological advantages, confirm that all biomass sources show emission of these substances on the level lower to coal. However, in the case of NOx , they appeared to be ecologically more oppressive.
Keywords: renewable sources, biomass combustion, fruit and vegetable wastes