Experiences with the Digital Twin of a Depropanizer Reboiler

Paper from the AFRC 2017 conference titled Experiences with the Digital Twin of a Depropanizer Reboiler

Wikipedia defines digital twins as "computerized companions of physical assets that can; be used for various purposes. Digital twins use data from sensors installed on physical; objects to represent their near real-time status, working condition or position." With this; paper we present the validation and integration of a digital twin into the continuous; operations of the refinery process heater serving as a reboiler for the bottoms of a; depropanizer tower at the HollyFrontier Refinery in Woods Cross, Utah.; This digital twinning technology was implemented in the refinery, debugged, tested,; hardened and calibrated throughout 2016. In February of 2017 the newly developed; instrument was commissioned and turned-over to refinery engineers and operators. The; integration of this instrument into refinery operations has resulted in:; i. increased refinery safety: by knowing the peak temperature on each coil of the reboiler,; a revision in operating strategy was implemented to minimize danger from tube rupture; in this alkylation unit.; ii. increased reboiler longevity: the local temperature and process fluid vapor-liquid; fractions throughout the coil run length made available by this instrument has made; possible a revision in the control strategy to optimize heat input to the alkylation column; while maintaining the operation strategy of a partial (vs. total) reboiler.; iii. insight into refinery operations: by trending the local information made available from; this continuous measurement, refinery engineers have been able to explain previously; unexplained refinery operations.