Reasearch And Realization On Energy-saving Controller For Air Conditoning System In Intelligent Building

The energy dissipation of air condition accounts for a large part of the whole dissipation in intelligent building.In order to ensure the temperature and relative humidity within allowable range,changing dew point method is needed. To make them accurate,HVAC engineers use single variable loop control method.This method works very well when there is only one loop.But when two or more loops work together,energy dissipation appears.So,taking analysis on the control process of air condition system to low down the dissipation of the system means a lot to the energy-saving of air conditon system.This paper takes analysis on two-pipe Constant Air Volume(CAV) Air Condition System.Presents decoupling and control strategy for the coupling between temperature and relative humidity in changing dew point method with the knowledge of HVAC,heat transfer,control theory and so on.Establish the mathematical model of control element in CAV Air Condition System with mechanism modeling method;The method of using absolute humidity as intermediate variable to controle relative humidity is proposed.Thus the coupling between temperature and relative humidity becomes the coupling between temperature and absolute humidity;Using feedforward decoupling method to decoupl the transfer function matrix between temperature and absolute humidity;Design the controller of decoupled system with the combination knowledge of traditional PID control method and fuzzy control method.Establish the membership functions of input and output variables and corresponding control rules.Build control models of the traditional constant air volume air conditioning system control,decoupled control system using conventional PID controller,decoupled system using adaptive Fuzzy-PID controller,and take simulation analysis on them.Take the amount of consumption of chilled energy and power consumption as Energy Saving Index.And analysis energy dissipation of those three systems with it. The final results show that the decoupled system using adaptive Fuzzy-PID controller is much more energy-saving than those other two systems.