Transition and Subjects of Heat Recovery Steam Generator (HRSG) for Combined Cycle Plant

Abstract

Factors regarding the heat recovery steam generator (HRSG) have drastically changed in the development of the gas turbine and needs of a higher thermal efficiency in recent years.
In the early 90's, gas turbine firing temperature increased from 1000°C which established in the 70's, to 1300°C
As a result, plant thermal efficiency improved from 40% to around 49% due to increasing the capacity of HRSG and the adoption of higher steam conditions in the reheat/triple-pressure system instead of the conventional non-reheat/single pressure system.
Here, subjects of the performance, system, structure and control in reheat/triple-pressure type HRSG are reported.