In this paper a dynamic model of a 1:1 refrigeration system is presented. The main modelling effort has been concentrated on a lumped parameter model of a shell and tube condenser. The model has shown good resemblance with experimental data from a test rig, regarding as well the static as the dynamic behavior. Based on this model the effects of the cross couplings has been examined. The influence of the cross couplings on the achievable control performance has been investigated. A MIMO controller is designed and the performance is compared with the control performance achieved by using a conventional SISO structure, which thus takes the cross couplings into account. Hereby the essential parameters that determines the magnitude of the interaction caused by the cross couplings has been clarified.
Proceedings of Ecos 2003, 2003
Refrigeration Systems; Control Schemes; Modelling; Shell and Tube Condenser