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Time‐optimal output control computations for a class of linear tubular processes
Author(s) -
Lim Henry C.
Publication year - 1970
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450480314
Subject(s) - heat exchanger , optimal control , control theory (sociology) , bang–bang control , distributed parameter system , computation , mathematics , transformation (genetics) , heat flux , partial differential equation , mathematical optimization , control (management) , heat transfer , mechanics , computer science , mathematical analysis , thermodynamics , physics , chemistry , algorithm , biochemistry , artificial intelligence , gene
Time‐optimal output control of a class of tubular processes described by partial differential equations is considered. A special transformation is used and the time‐optimal control is derived by using a lumped‐parameter theorem, thus circumventing computational complexity associated with distributed‐parameter systems. Time‐optimal controls are given for a number of examples, thin‐wall steam‐to‐fluid heat exchangers and single‐pipe heat exchangers with wall temperature and wall flux control. In some cases a bang‐bang control of a related lumped‐parameter process may be taken, for all practical purposes, as optimal, for example, a thin‐wall steam‐to‐air heat exchanger. However, in general, time optimal control is complex, requiring a bang‐bang control followed by an infinite number of switches between diminishing non‐extremal values.