Development of a numerical model to estimate the fatigue life of heat recovery devices for micro gas turbines

Abstract

In this work it is analysed the COMPACT heat exchanger produced by ACTE company, in Ans. Here two gases move counter courant along the element, through different clefts between thin steel plates. In contrast to classic plate exchangers, the ACTE exchangers are constructed around a spiral core which provides curved shapes to the exchange surfaces. This way, subjected to a sudden temperature change, the plate expands in a predictable way. Consequently, thermal stresses and the lifetime of the exchanger can be computed.

To conduct this study, the exchanger is modelled by using Lagamine, a FEM software developed in ULG, in order to predict the heat exchanger’s lifetime. Because of the lack of key experimental data, many assumptions are imposed. For this reason, more than a precise estimation of the exchanger’s lifetime, this work can be read as a guide regarding the issues to be mainly faced in order to obtain an adequate modelling of the exchanger in future works.