Heat Exchanger Control Systems

Heat Exchanger Control SystemsSome Types of Heat ExchangersSensible Heat Cooling and HeatingChange of Phase Boilers and CondensersPartial Condensing or Partial Vaporization Wiped Film Units for Viscous FluidsBasic Model

Riggs & Karim, Chemical and Bio-Process Control, 2006, p. 12Control Loop OptionsFeedback has some lag time

Feedforward based on steady state process

Perry, Chemical Engineers Handbook, 7th Ed., p. 8-17Alternate Methods Bypass Control Options

Combined Feedback & FeedForward

Marlin, Process Control Designing Processes and Control Systems for Dynamic Performance, 2000, p.784

Riggs & Karim, Chemical and Bio-Process Control, 2006 p. 401Physical Installation Cascade control

http://www.spiraxsarco.com/resources/steam-engineering-tutorials/control-applications/pressure-control-applications.aspChange of Phase HXCondenser on Distillation Column

http://eweb.chemeng.ed.ac.uk/courses/control/restricted/course/fourth/course/module3-1.htmlChange of Phase HXPartial Condenser on Distillation Column

http://eweb.chemeng.ed.ac.uk/courses/control/restricted/course/fourth/course/module3-1.html

Change of Phase HXReboiler on Distillation Column

http://eweb.chemeng.ed.ac.uk/courses/control/restricted/course/answers/fourth/answer2.html

Condenser Pressure Control

Towler & Sinnott, Chemical Engineering Design Principles, Practice and Economics of Process Design, 2008, p. 279Steam Boiler ControlSteam Pressure is used to control fuel feed rates

Can be linked to consumer

http://www.powermag.com/issues/features/Drum-pressure-the-key-to-managing-boiler-stored-energy_300.htmlActual Boiler Control Systems Allow for capacitance in system

http://www.powermag.com/issues/features/Drum-pressure-the-key-to-managing-boiler-stored-energy_300.htmlBoiler Drum Level ControlCan use feedback, feedforward & combination

Riggs & Karim, Chemical and Bio-Process Control, 2006, p. 12

Partial Condenser OptionsCan control reflux rate

William L. Luyben, Alternative Control Structures for Distillation Columns with PartialCondensers, Ind. Eng. Chem. Res. 2004, 43, 6416-6429

Partial Condenser OptionsCan control condenser cooling rate

William L. Luyben, Alternative Control Structures for Distillation Columns with PartialCondensers, Ind. Eng. Chem. Res. 2004, 43, 6416-6429

Partial Condenser OptionsCan control reflux ratio

William L. Luyben, Alternative Control Structures for Distillation Columns with PartialCondensers, Ind. Eng. Chem. Res. 2004, 43, 6416-6429

Wiped Film EvaporatorControl product feed rate

http://www.artisanind.com/ps/docs/rototherm.pdf