The customer operated an old front admission steam turbine (TuW-2 built in 1977), which had reached the end of the design-lifetime. Furthermore, several damages had been detected that required extensive turbine repairs. In addition, the operation parameters changed (higher steam flow / higher power output) due to a new steam boiler that had been installed previously. Beginning of 2014, the customer approached Siemens Energy to provide a suitable footprint solution.
In order to find the best possible solution and to meet the customer's requirements, the whole turbo set was examined in detail via an engineering study. To optimize the complete water-steam cycle, the final scope included not only a SST-600 footprint turbine with new coupling, gearbox, and TURLOOP control and protection system, but also a footprint generator and new steam cycle components including preheater and condensate pumps.
Despite the rather extensive modifications on site, the footprint solution still was preferred to a new train or revamp because of shorter shutdown time due to the re-use of existing foundation, condenser, and other auxiliaries.
The tailored footprint solution fulfilled the customers expectations of steam inlet flow & power increase and optimization of operational flexibility and turbine availability while re-using the existing foundation minimized the shut-down time. By using the footprint concept instead of repairing the whole turbine the customer saved several weeks of shutdown time and efficiently optimized the complete steam cycle.