The Application Of Multivariable Intelligent Decoupling Control In Variable-Air-Volume Conditioning System

Variable air volume(VAV) conditioning system is multivariable,strongly coupled, nonlinear and time variant,so its design,performance are more difficult than constant air volume(CAV) conditioning system.Recently,VAV conditioning system is more and more popular in engineering application,because of its extraordinary energy saving and comfortable features.Based on the above,the research on VAV conditioning system attracts more attentions.Nowadays,the research on VAV condition system mainly focus on stable performance and energy saving.Stable performance of VAV conditioning system has been deeply studied in this paper.The VAV conditioning system can not run steady because of the coupling among the different subsystems.Based on feedforward compensation,decoupling control system has been designed for the coupling between two air-handling units(AHU) and the coupling between water system and air-flow system.Meanwhile,carry on simulation research and experiment.Firstly,introduce the basic state of VAV conditioning system,analyze the"coupling system of two AHU"and"coupling system of water system and air-flow system",then design modeling experiment to obtain the mathematics models of coupling plants.Secondly,design the PID self-tuning controller and decoupling control network,meanwhile testify the feasibility and validity of the controller and the network by simulation.At last,program by using Lab VIEW to run the VAV conditioning system in Intelligent Building Research Institute of Xi'an University of Architecture and Technology.The feasibility and validity of the decoupling control scheme has been proved through experiment.The results of simulation and experiment are satisfying,pave the way for the stable performance of VAV air conditioning system, which can be applied in engineering later.