Bounded positive control for double-pipe heat exchangers

In this work, an outlet temperature control scheme for double-pipe heat exchangers is proposed. Compared to previously proposed approaches, the algorithm developed here takes into account and actually exploits the analytical and stability properties inherent to the open-loop dynamics. As a result, outlet temperature regulation is achieved through a simple controller which does not need to feed back the whole state vector and does not depend on the exact value of the process parameters. Moreover, the proposed approach guarantees positivity and boundedness of the input flow rate without entailing a complex control algorithm. The analytical developments are corroborated through simulation and experimental results.