New Steel Alloys for the Design of Heat Recovery Steam Generator Components of Combined Cycle Gas Plants

Demand of Power is growing everyday, mainly due to emerging economies in CRIB countries (China, Russia, India and Brazil). During the last fifty years steam pressure and temperature in power plants have been continuously raised to improve thermal efficiency. Recent efforts to improve efficiency leads to the development of a new generation of Heat Recovery Steam Generator (HRSG) where the Benson Once-Through Technology is applied to improve thermal efficiency. The main purpose of this paper is to analyse the mechanical behaviour of a High Pressure Superheater Manifold by applying Finite Element Modelling (FEM) and a Finite Element Analysis with the objective to analyse stress propagation leading to the study of damage mechanism e.g. Uniaxial Fatigue, Uniaxial Creep for life prediction. The objective of this paper is also to analyse the mechanical properties of the new high temperature resistant materials in the market such as 2Cr Bainitic steels (T/P23, T/P24) and also the 9–12Cr Martensitic steels (T/P91, T/P92, E911 and P/T122). For this study the design rules for construction of power boilers to define the geometry of the HPSH Manifold were applied.