Analiza możliwości modernizacji nadkrytycznych bloków wȩglowych średniotempera turowych poprzez dostawienie członu wysokotemperaturowego

This paper presents a feasibility study of a modernization of an existing power generating unit aimed to improve its performance. Two basic modernization options are under investigation. The idea behind the first one is a live steam temperature increase. Such modification requires a superheater upgrade. The piping in the hottest section must be made of materials able to resist high temperature. The solutions provided for this option assume a reconstruction of the steam boiler or an addition of a separate gas boiler. The modernization involves also the exchange of the high pressure part of a turbine. The solution described above requires also a detailed analysis of the operating conditions of the reheater, due to the altered temperature at the outlet of the new HP turbine part. Therefore the modeling within the framework of the study involved the whole steam cycle, together with the boiler and the reheater, the HP turbine part and the heat regeneration system. The research analyzed the live steam temperature changes in the range 600-700°C. The concept of the second modernization option is to increase the reheat steam temperature, while the live steam temperature remains unchanged. Such approach requires the exchange of the intermediate turbine part and the reconstruction of the reheat superheater either within the existing design or through the addition of a gas boiler. The reheat steam temperature may vary between 620 and 720°C.