Simplified approach for creep evaluation in superheaters

Abstract

This paper is focused on the estimation of temperature distribution on superheater tube bundles for the consequent creep damage evaluation. The precision of estimated temperatures is very important because it significantly affects residual creep life. Conditions in the tube bundle can be simulated using CFD, however, a full 3D simulation would be computationally intensive and not fit for practical use. In order to mitigate this issue, the new approach considered in this paper uses a series of 2D CFD simulations in multiple sections using known inlet flow conditions. Those conditions have been investigated in previous work using 3D CFD simulation of flue gas flow starting in the combustion chamber and ending just before the superheater in the second pass. The paper also deals with possible temperature differences that may arise due to simplifications in the proposed approach. Lastly, the residual creep life is estimated using obtained temperature distribution on the tube bundle.This paper is focused on the estimation of temperature distribution on superheater tube bundles for the consequent creep damage evaluation. The precision of estimated temperatures is very important because it significantly affects residual creep life. Conditions in the tube bundle can be simulated using CFD, however, a full 3D simulation would be computationally intensive and not fit for practical use. In order to mitigate this issue, the new approach considered in this paper uses a series of 2D CFD simulations in multiple sections using known inlet flow conditions. Those conditions have been investigated in previous work using 3D CFD simulation of flue gas flow starting in the combustion chamber and ending just before the superheater in the second pass. The paper also deals with possible temperature differences that may arise due to simplifications in the proposed approach. Lastly, the residual creep life is estimated using obtained temperature distribution on the tube bundle.