Dynamic matrix control applied on propane-mixed refrigerant liquefaction process

Abstract

This study proposes a dynamic matrix control strategy that produces control input sequences which are more robust and reduce power consumption than conventional proportional-integral (PI) controllers when applied to the C3MR liquefaction process. First, a rigorous process dynamic model was constructed in Aspen HYSYS Dynamics 7.3 and MATLAB 2014a which calculates dynamic responses for two different scenarios of unmeasured step disturbances increasing the load of liquefaction energy. Then, a DMC module including the manipulation of the compressor speed was formulated. The simulations using the proposed DMC module demonstrate that the multivariable optimal control increases the energy efficiency and robustness of a complex liquefaction cycle process.