NOTE: Restrictions are in place to limit access to one or more of the files associated with this item. Authorized users must log in to gain access. Non-authorized users do not have access to these files.
Visit the Energy Systems Laboratory Homepage.
Topping Turbines: Adding New Life to Older Plants
An existing power plant can be repowered at a modest investment cost through a topping turbine installation. Essentially, this consists of replacing the existing old, low pressure boilers with new, high pressure boilers and adding a new, high pressure, non-condensing turbine (topping turbine) . The high pressure steam generated in the new boilers is supplied to the throttle of the high pressure turbine and exhausted at the pressure required by the existing, old, low pressure, condensing turbines. The exhaust from the topping turbine is then supplied to the throttle of the existing turbines. The additional capacity results from the kilowatts generated in the topping turbine while reducing the steam pressure from the throttle to the exhaust conditions. Also, because this steam is not condensed, there is no loss of the latent heat of condensation of the steam to the condenser circulating water. Consequently, the thermal efficiency of the cycle is considerably enhanced.
Cadrecha, M. (1984). Topping Turbines: Adding New Life to Older Plants. Energy Systems Laboratory (http://esl.tamu.edu); Texas A&M University (http://www.tamu.edu). Available electronically from