Combined Cycle Steam and Feedwater Operating Principles

 When you finish this lesson, you will be able to describe the feedwater and steam flowpaths in a typical combined cycle power plant. You will also be able to explain the HRSG design principles governing plant operation. • Describe the system flow path of a basic single-pressure cycle • Describe the function of the following components of an HRSG: – Economizer – Evaporator – Superheater • Explain the concept of a pinch point • Describe the system flow path of a dual-pressure (HP and LP) cycle • Describe the system flow path of a triple-pressure (HP, IP, and LP) cycle • Explain the purpose of a pegging steam line • Describe the system flow path of a triple-pressure cycle with reheat • Explain the operation of an HRSG feedwater pump • Describe the function of a steam attemperator