Research On Terminal Device Of VAV Air-conditioning System Based On BAS3000 DDC Controller

With the increasing calls for energy saving, VAV,(Variable air volume) air-conditioning system energy saving as one effective way, VAV air conditioning system as an effective way of building energy consumption is Widely used in central air conditoning system. VAV air conditioning system, through terminal devices (VAV BOX) to adjust the air volume air-conditioning area,maintain room temperature's balance intelligently.As it,VAV BOX ,as the key component of VAV air conditioning system,directly affect the efficiency of VAV system。This article relies on variable air volume laboratory of Institute of Intelligent Building in Xi'an University of Architecture and Technology, study the structure and dynamic performance of pressure-independent VAV BOX. The air volume control loop is analyzed designing temperature controller by computer using indirect closed-loop identification method.And,the temperature control loop is analyzed by theoretical modeling with system identification. Based on existing equipment, design double closed-loop PID controller.By modified simplex method to optimization parameters of the air volume controller and temperature controller online.The control system is simulated in MATLAB,the experiment shows that it can eliminate the random noise's effects. Finally, selecting the BAS-3000 DDC as controller of VAV BOX。The control logic is completed by Webaccess and BASPro and tested in air conditioning system.The control effect are satisfactory.