The Study Of Decoupling Control In Variable-air-volume Conditioning System

Variable Air Volume System (Variable Air Volume Air Conditioning System) achieves energy saving purposes, by adjusting blower speed based on changes of terminal load and reducing the loss of fans. In currently, because of its huge potential on energy saving, VAV system is increasingly popular in applications of intelligent building. But also, VAV system has some characteristics such as multivariable, nonlinear and strong coupling. So the design and operation of the system is hard to achieve. On the other hand, only after a long run, the advantages of VAV system can be shown, which also affect the development and application of VAV system.In this paper, Attention is concentrated on studying the decoupling control of VAV system. Based on analyzing the coupled objects, a decoupling control network be designed, and its feasibility is verified by simulation and experiment. Two temperature control loops of terminals and an air concentration of carbon dioxide control loop are research objects of this paper. At first, a decoupling system, based on feed-forward compensation, has been designed. Secondly, based on experimental data, the mathematics model of coupling plants is built, the adaptive PID controller based on a Neural network is designed, and the feasibility of the decoupling control is verified by simulation. Lastly, based on VAV conditioning laboratory in Xi'an University of Architecture and Technology, design experimental program to verify the effectively and feasibility of the decoupling control system. The results of simulation and experiment are not only satisfying but also provide a reference for practical engineering application.