ISSN Online: 2377-424X
ISBN Print: 978-1-56700-421-2
International Heat Transfer Conference 15
Optimization of Life Time Expectance for Heat Exchangers with Special Requirements
Аннотация
Heat exchangers of different types have a variety of expectances of lifetime and lifetime is governed by
fatigue effects. Fatigue may occur for steel components like straight tube heat exchangers (STHE) as well as
for aluminium components like aluminium brazed plate fin heat exchangers (PFHE), if the combination of
stress amplitudes and frequency is high enough.
Linde’s aim is to improve heat exchanger design, process conditions and operational procedures to optimize
lifetime expectance and thus ensure high plant availability. For detailed analysis, start-up and offset scenar-
ios are defined with all impact on heat exchangers (input conditions, frequency of scenarios, etc.). Linde has
elaborated tools and procedures to investigate both stationary and unsteady conditions. If required, rigorous
dynamic process simulations for heat exchangers with user-defined or pre-defined local and transient heat
transfer and pressure drop correlations, including relevant unit operations (e.g. expanders, valves, separators,
splits, etc.) can be performed within Linde’s in-house process simulation environment OPTISIMR ?. The re-
sulting profiles for temperatures and heat transfer coefficients are input for succeeding FEM analysis, which is
the structural mechanic basis for lifetime estimation. Subsequently, heat exchanger design may be optimized
and further-on operation procedures and process conditions may be improved. Furthermore, also the accumu-
lated lifetime consumption for existing equipment already years in operation can be examined, if sufficient
information is available. Thus unplanned shut-downs can be avoided as heat exchangers with low remaining
lifetime expectance can be replaced in time