Efficiency Improvements On Large Mechanical Drive Steam Turbines.
MetadataShow full item record
Many of the mechanical drive steam turbines in service in the world today were designed without the demands for optimum efficiency. In order to meet the changing economic requirements that plants face, technological solutions have been developed to improve turbine performance that can be sustained during extended run times. This is in contrast to making conventional component replacements with short-lived or limited gains in performance. Another important consideration is that performance upgrades must be made without adversely impacting the turbine’s operating characteristics, especially those during startup. Turbine efficiency is significantly affected by the performance of shaft and tip seals that control steam leakage within the machine. Conventional seals have a long history of sacrificing operational characteristics by rubbing during unit startup and producing vibration problems that can result in aborted startups. Extended startups are the short-term loss, yet the loss of installed seal clearances has a cumulative financial impact over the operational run cycle. With the application of retractable packing to prevent rubbing during startups, tip seals not included in the OEM design may be successfully added to provide sustained thermal and operational performance improvements. These features have been successfully implemented on two mechanical drive steam turbines in an ethylene plant in Orange, Texas. Presented will be performance gains realized and experience during startup with these features.
Terezakis, Terry N.; Sulda, Erik M.; Little, Nathan T. (2001). Efficiency Improvements On Large Mechanical Drive Steam Turbines.. Texas A&M University. Turbomachinery Laboratories. Available electronically from