Study And Design On The VAV BOX Controller Of VAV Air-conditioning System

Because of the global warming and environmental change, HVAC system as the core of the Building Automation System, its intelligence is the key of a significant reduction in building energy consumption and the effect of environmental control. But in the real system, air conditioning systems are generally running under partial load, up to less than maximum design load, there is a big waste of energy. Therefore, the high-efficiency, low power operation under low-load of the air conditioning is the key for HVAC systems.VAV BOX is the key component of VAV air conditioning system. Its operating conditions directly affect the operating results of the air conditioning system. This paper is based on VAV conditioning laboratory platform of Institute of Intelligent Buildings in Xi'an University of Architecture and Technology, the pressure -dependent VAV BOX is identified. The air damper is analyzed using an open-loop identification method, the room model analyzed with a closed-loop identification method. Moreover, according to the particularity of the system, the pressure -independent controller, is designed.The inloop controller is PI, while the outloop is pattern recognition adaptive controller (PRAC). The closed-loop controllers are simulated in MATLABA, and running in experimental system, the results are satifactory. Finally, the hardware structure of VAV control system is researched based on embedded LPC2400 series of ZLG ARM7.