| From the viewpoint of saving energy and improving the quality of the indoor environment, it is important to adopt an efficient adjustment strategy for air conditioning systems. Nowadays variable chilled water volume system (VWV) is an effective energy-saving method,which has a smaller size of pipe and equipment than the normal ones for it has considered the dispersing rate of the load in the systems. However since VWV system is multivariable, strongly coupled, nonlinear and time variant, its design performance and management are more difficult than constant flow chilled water volume system's. What's more, stable control of the entire VWV system is focused on particularly in fact engineering.This paper mainly studies the stability of VWV system, which is necessary for VWV system's operation. Firstly, the paper analyses the model of VWV system, and divides it into two parts—water chilling units and terminal units reasonably basing on dividing and coordinating strategies, builds up models for AHU and terminal Units respectively by identification and mechanism as well as finds out the coupled relationship among variables. The paper proposes neural network intelligent decoupling method based open loop for water chilling units, which has coupled variables, and applied fuzzy control respectively for the terminal units and water chilling units decoupled, defines reasonable membership functions for each variable and fuzzy control rules, obtaining control table of output variables. Secondly, the paper utilizes the distributing characteristic of BAS (building automation and control system) to control coordinately integrating water chilling units and terminal units as a whole part, based on total water volume, making VWV system attain stable status quickly . Finally the paper establishes simulating models for VWV system with MATLAB software to prove out that the intelligent decoupling control of VWV system is reasonable .The results of simulating is satisfied.
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