Modeling,control And Simulation For The Refrigerator System Of Offshore Platform

Cold storage refrigeration system is a complicated nonlinear system with MIMO, coupling, time-varying, and its refrigerating performance will be influenced by running condition and cold load. So establishing offshore platform cold storage refrigeration system mathematic model for controlling simulation and researching the multivariable control method of refrigeration system are very necessary. so that we can obtain ideal effect of control quality and energy saving effect.This research proposes a control method combining inverter compressor and electronic expansion valve based on multivariable controller for offshore platform cold storage refrigeration system. The control method include fuzzy PID controller and max COP controller. Finally for optimizing temperature and system COP value.This research contain such as:Firstly, establishing offshore platform cold storage nonlinear mathematical model described by state-space for control simulation of refrigeration system. And then, Based on the theory of fuzzy PID controller and max COP controller, It is designed a multivariable stable fuzzy controller for a class of MIMO complicated system such as refrigeration system.Furthermore, considering load-varying and refrigeration energy cost regulation problem, in order to optimize COP value, by regulating refrigeration capacity and electronic expansion valve, to meet design energy effect requirement. So we can improve refrigeration energy saving effect obvious.Last, the simulating results demonstrate that the established MIMO model is right and controller can adapt the changes of running condition and cold load. Temperature regulation and max COP can meet user setting requirement, so it has good applying prospect in refrigerating control area.