(134f) Remaining Life Assessments of Refinery Cokr Furnace Tubes Using Omega Simulations

Remaining Life Assessments of Refinery Coker Furnace
Tubes Using Omega Simulations

Gerald W. Wilks,
Lemont Refinery, CITGO Petroleum Inc.

Abstract

Process simulations
are used frequently in refineries to determine the optimum operating parameters
for a wide range of processes. The development of Omega technology by the oil
industry in the 1990's led a new type of simulation that made it possible to
assess both the effects of corrosion and past high temperature service on the
life of refinery equipment.  This
technology also made it possible to predict future equipment performance based
on proposed process changes.  Furnace
tubes are a type of high temperature equipment that is well suited to Omega
simulation analyses.  However, in Coker
furnaces the accumulation of coke in the tubes leads to gradual changes in
temperature and pressure that make accurate simulations of the furnace difficult.
 Furnace tubes typically fail due to the
combination of corrosion and creep processes, and with changes occurring in temperature
and pressure, the rate of degradation from corrosion and creep are also continuously
changing.  This paper describes how
corrosion data and process data can be used in Omega simulations to obtain
accurate assessments of furnace tube remaining life.  Included in this paper is an explanation of
how anticipated changes in process conditions can be evaluated with Omega
simulations to determine the impact of those process changes on the remaining
life of coker furnace tubes.