Reference: SST-600 Footprint turbine
The customer operated a SST-600 steam turbine which was first commissioned in 2012. About 50.000 operating hours later, during the major overhaul in 2018, severe damages at the turbine were detected. In particular, the casing, the rotor and the guide blade carrier were affected by erosion and corrosion.
Due to the negative impact of these damages to the turbine safety and the reliability of operation, the customer got in contact with Siemens Energy in the beginning of 2019 to find the most suitable solution.
Siemens Energy recommended to install an identical footprint turbine regarding dimensions and thermodynamic design to profit from the possibility of re-using existing spare parts, foundation, piping as well as the control and protection system. In order to prevent the turbine from repeated corrosion and erosion, the new footprint turbine was manufactured with enhanced material.
Furthermore, the efficient replacement of a complete turbine leads to a decrease in downtime (well plannable conversion since no surprising repair works have to be expected) and therefore to significant cost savings. The customer agreed to the modernization and the turbine already has been manufactured in Germany due to its size and weight.
With a crucial delivery time of approximately 15 months the project will be completed soon. The lifetime of the steam turbine will be extended, the risk of unplanned shutdowns will be minimized and the new material will serve as prevention from further damages.
Shown in below figure, considering production losses per day, the footprint concept is recommended as the most economical solution compared to turbine revamps and/or Overhaul & Repair.