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Heat Exchanger Control Systems. Some Types of Heat Exchangers. Sensible Heat Cooling and Heating Change of Phase Boilers and Condensers Partial Condensing or Partial Vaporization Wiped Film Units for Viscous Fluids. Basic Model. Simple Heater Loop Actual loop on P&ID.
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Some Types of Heat Exchangers • Sensible Heat Cooling and Heating • Change of Phase Boilers and Condensers • Partial Condensing or Partial Vaporization • Wiped Film Units for Viscous Fluids
Basic Model • Simple Heater Loop • Actual loop on P&ID Riggs & Karim, Chemical and Bio-Process Control, 2006, p. 12
Control Loop Options • Feedback has some lag time • Feedforward based on steady state process Perry, Chemical Engineers Handbook, 7th Ed., p. 8-17
Alternate 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. 401
Physical Installation • Cascade control http://www.spiraxsarco.com/resources/steam-engineering-tutorials/control-applications/pressure-control-applications.asp
Change of Phase HX • Condenser on Distillation Column http://eweb.chemeng.ed.ac.uk/courses/control/restricted/course/fourth/course/module3-1.html
Change of Phase HX • Partial Condenser on Distillation Column http://eweb.chemeng.ed.ac.uk/courses/control/restricted/course/fourth/course/module3-1.html
Change of Phase HX • Reboiler 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. 279
Steam Boiler Control • Steam 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.html
Actual Boiler Control Systems • Allow for capacitance in system http://www.powermag.com/issues/features/Drum-pressure-the-key-to-managing-boiler-stored-energy_300.html
Boiler Drum Level Control • Can use feedback, feedforward & combination Riggs & Karim, Chemical and Bio-Process Control, 2006, p. 12
Partial Condenser Options • Can control reflux rate William L. Luyben, Alternative Control Structures for Distillation Columns with Partial Condensers, Ind. Eng. Chem. Res. 2004, 43, 6416-6429
Partial Condenser Options • Can control condenser cooling rate William L. Luyben, Alternative Control Structures for Distillation Columns with Partial Condensers, Ind. Eng. Chem. Res. 2004, 43, 6416-6429
Partial Condenser Options • Can control reflux ratio William L. Luyben, Alternative Control Structures for Distillation Columns with Partial Condensers, Ind. Eng. Chem. Res. 2004, 43, 6416-6429
Wiped Film Evaporator • Control product feed rate http://www.artisanind.com/ps/docs/rototherm.pdf