(91b) Heater Pass Balancing using MPC on a Redundant DCS node

A multivariable controller to balance heat distribution by adjusting individual heater pass flows, while maintaining upstream level control and managing other process constraints was implemented in a redundant DCS node. The controller overcame various instrumentation issues including significant valve stiction to reduce heater pass imbalances, skin temperature excursions, and improve upstream level stability across a wide range of process flow rates. The controller was designed and implemented using Lin and Associates' Model-less Multivariable Controller, Deltum-XMC, installed in the Honeywell Experion C300 control node, and commissioned in less than a calendar-week without step-tests or process modeling. The controller is running at a 2-second in the C300 which is a redundant control node.