Heat Rate Optimization

The objective of this module is to present the factors affecting turbine cycle efficiency to increase the operator’s awareness and effectiveness in controlling heat rate.

Upon completion of this module and workbook, the operator should understand:

• The reasons for heating feedwater before it enters the boiler.
• The difference between a ‘closed’ and an ‘open’ feedwater heater.
• How to calculate the ‘Terminal Temperature Difference’ (TTD) of a feedwater heater.
• How to calculate the ‘degree of approach’ for a drain cooler in a feedwater heater.
• The effect that insufficient venting has on performance of a feedwater heater.
• The effect that a high drain level will have on feedwater performance.
• The impact that bypassing feedwater heaters has on efficiency and reliability.
• The problems that can arise in the operation of the boiler as a result of inadequate feedwater heating.
• How to determine the proper amount of venting of a deaerator.
• What causes pump cavitation.
• What Net Positive Suction Head (NPSH) is and how an adequate NPSH is provided for different pumps in the power plant.
• The relationships between centrifugal pump flow, discharge pressure, power consumption and efficiency.
• How load ‘swinging’ adversely affects efficiency.
• How to improve power plant efficiency by removing certain auxiliary equipment from service at low loads.