Optimization of the combined cogeneration plant in order to achieve high efficiency criteria

Tema ovog diplomskog rada je optimiranje kombiniranog kogeneracijskog postrojenja u cilju postizanja kriterija visoke učinkovitosti. Postrojenje za koje je provedena analiza je blok C u TE-TO Sisak, instalirane snage 230 MWe/50 MWt. U tu svrhu napravljen je matematički model plinsko-turbinskog dijela, kotla na ispušne plinove iz plinske turbine i parno-turbinskog dijela postrojenja u programskom alatu Ebsilon Professional, u kojem je provedena analiza rada postrojenja za različita opterećenja plinske turbine i pri različitim okolišnim uvjetima. Prikazan je detaljan utjecaj promjene tlaka, temperature i relativne vlažnosti okolišnog zraka na rad postrojenja te rad postrojenja i emisije za zimsko, prijelazno i ljetno razdoblje. Analiziran je i rad postrojenja u ovisnosti o toplinskoj snazi pare oduzimanja. S obzirom da je cilj da blok C postane visokoučinkovito kogeneracijsko postrojenje te ostvari poticaje, opisani su uvjeti koje je potrebno zadovoljiti da bi postrojenje steklo status povlaštenog proizvođača električne energije. Prikazan je izračun uštede primarne energije za kogeneracijska postrojenja. Optimiranje postrojenja je provedeno promjenom parametara oduzimanja pare na kondenzacijskoj parnoj turbini i povećanjem toplinske snage postrojenja te su dani rezultati. Prikazana je usporedba proizvedene i utrošene energije te usporedba prihoda i troškova za postojeće i poboljšano postrojenje.Subject of this thesis is optimization of the combined cogeneration plant in order to achieve high efficiency criteria. Analysis was conducted for CHP plant Sisak C, which has installed power of 230 MWe/50 MWt. Mathematical model of a gas turbine, heat recovery steam generator and steam turbine was made in the software Ebsilon Professional. In Ebsilon, analysis of a different gas turbine loads and different environmental conditions was conducted. A detailed influence of the change of pressure, temperature and relative air humidity was shown. Emissions were calculated for winter, spring and summer period. Influence of the thermal power of the extraction steam was also shown. Since the goal is to achieve high efficiency criteria and thus get incentives, terms that need to be fulfilled, in order to plant acquire status of a favored electricity producer, was described. Calculation of the primary energy saving for cogeneration plant was shown. Optimization of the plant was carried out by changing parameters of extraction steam and by increasing thermal power output of the plant. Energy production and consumption, income and expenditure were compared for existing plant and for improved plant