| Due to its load shifting and electrcity charge saving characteristics,ice storage air conditioning has been received increasing attention by energy sector since 1990s.However,because the ice melting process of ice storage air conditioning system is a time variant,nonlinear and time delay system,it is so hard to establish a precise mathematical modle that the control stratage of the system is still at relatively backward level,which always resulting in the wast of cold energy and making little sense of energy saving and environmental protection.The dissertation firstly analyses the operating principle and common contorl strategy of ice storage air conditioning systemm,and then addresses the issue of provincial government building ice storage air conditioning,establishes a time seriers model(ARMA),using the system identification tool box of matlab software,according to the cooling load historical data of this building during summertime.And on this basis,a control strategy based on load prediction is given to coduct the operation of the system.Secondly,the design of GPC controller based on PID structure is present to control the melting process of this system,which can overcome some disadvantages of conventional PID controller.Finally,a modle between glycol solution valve of ice-tank outlet and the temperature of water divider is indentified with the ralated data of melting process by means ofmatlab.And this modle is used for system simulation.The simulation results indicate that the algorithm is capable of keeping its follow-up behavior in the presence of disturbance due to plant parameter variation,and has perfect control effect,which is of great reference value for the optimal control of ice storage air conditioning system. |
