Heat Rate Optimization

The objective of this module is to present the factors affecting turbine cycle efficiency to increase operators’ awareness of these matters and improve their effectiveness in controlling heat rate.

Upon completion of this videotape and the associated workbook exercises, the operator should understand:

• The definition of turbine cycle efficiency.
• The effects on efficiency and generation for changes in throttle pressure.
• The effects on efficiency and generation for changes in main steam temperature.
• The effects that low reheat steam temperature have on efficiency and generation.
• What throttling losses are and why they occur.
• What is meant by “sliding pressure” operation and why this mode of operation increases efficiency.
• What turbine “exhaust leaving-losses” are and what role the operator plays in controlling these losses.
• The impact on efficiency and generation when feedwater heaters are removed from service or not performing properly.
• Why dissolved silica concentrations are monitored and controlled in the boiler water.
• How low reheat steam temperatures can result in damage to turbine blades.
• “Leakage” steam paths within the turbine and their impact on efficiency and generation.
• What impact generator hydrogen pressure has on efficiency and generator capability