WELDING TECHNOLOGY FOR INTERNAL PIPELINES ON POWER PLANT KUSILE 6X800 MW

Ekonomski razvoj Južnoafričke Republike uvjetovan je sigurnom opskrbom električne energije. U svrhu pokrivanja potrebnog baznog opterećenja, grade se dvije moderne termoelektrane na ugljen, Medupi i Kusile, svaka kapaciteta 4800 MW što čini 25 % trenutno raspoložive električne energije u Južnoj Africi. Radi nedostatka vode, kako pitke tako i rashladne, termoelektrane će imati zrakom hlađene kondenzatore koji će biti najveće postrojenje takvog tipa u svijetu. Iskoristivost takvih kondenzatora ovisi ponajviše o vanjskim uvjetima zraka, prvenstveno o temperaturi koja je za to područje doseže preko 40 °C. U ovom diplomskom radu prikazano je sljedeće: U prvoj točki navedeni su i opisani reprezentativni oblici elektrana s kraćim osvrtom na termoelektranu Kusile (6 X 800 MW) i kraćim osvrtom na cjevovode. U drugoj točki su navedeni najzastupljeniji osnovni materijali koji se koriste na termoelektrani Kusile, opisana su dva postupka zavarivanja koja se tamo koriste, oblici i priprema žljebova za zavarivanje te zahtjevi za kvalitetom. Treća točka se bavi tehnologijom zavarivanja cjevovoda kotlova, te metodama ispitivanja istih. Prikazani su i reprezentativni WPS-ovi i PQR-ovi.The economic development of South Africa depends of secure electric power supply. In order to cover the required base load, two modern coal power plants, Medupi and Kusile, are being built, each with a capacity of 4800 MW, which is 25 % of currently available electric power in South Africa. Due to the lack of water, Medupi and Kusile will have an air cooled condensers, which will be the largest condensers of this type in the world. The efficiency of these condensors depends largely on external air conditions, particularly air temperature, which for South African area reaches over 40 °C. This thesis consists of next: In the first part are mentioned and descibed representative types of power plants with short cuts about power plant Kusile (6 x 800 MW) and short cuts on pipelines. Second part is dealing with the most representative base metals which are in use on power plant Kusile. As there are descibed two welding processes that are using there, types and preparations of welding grooves and quality requirements. The third part is about welding technology for boiler's pipelines and the non-destructive examinations of the same. There are also shown representative WPSs and WPQRs