Research Of The VAV Air-conditioning System Hierarchical Optimization Control Based On Coordination

Central air-conditioning is the large energy consumption of modern construction, itis almost50%~70%percent of the whole building energy consumption.Usually thedesign of air-conditioning system is on the most unfavorable condition, generally isaccording the maximum load. But actually,air-conditioning system always work in partload.It can be90%time. The ability of air treatment equipment has a lot of rich.Therefore, it adjustment also has a lot of flexibility. VAV (Variable AirVolume)air-conditioning system is a full air conditioning system. It meet the change ofload and comfort requirements by adjust the air volume. Because of its no condensationwater disasters, design system agile, high efficiency and energy saving.It has a widerange of applications. However, the VAV air-conditioning system has nonlinear, delay,strong coupling, multivariable and disturbance characteristics, it is difficult to adapt tothe control requirements by traditional control mode.This makes the energyconservation and comfort in VAV system not fully reflected. Through the optimizationcontrol, how to make the air-conditioning system in comfort, stable operation, andminimize the system energy consumption, will become the focus of research.Because the air conditioning system have a lot of equipments, fault frequencybecome higher. Fault will increase energy consumption and reduce indoor comfort. Atthe same time, it will increase the equipment loss, affect the service life. So make surethe VAV system is running in trouble-free state has very important practical significance.It has the good effect to prevent accidents, improve equipment effective use and prolongits service life.This article use the improved neural network to establish load model and obtain theenergy consumption. Then compared the forecast energy consumption and the actual consumption values in operation process. Fault state use statistical methods for faultdetection. To ensure the VAV system is running in trouble-free state. The system use acoordination control based on global hierarchical optimization. Decomposition andestablish the system static model according to the working principle of VAV system andthrough experiment. Puts forward the multi-objective optimization of VAV system. Thisoptimize can established optimization setting values for each controller. The goal ofoptimization control is more comfort and less energy conservation. According to themain parts of system model, the energy balance equation and components of thephysical limit, define the global energy saving optimization objective function andconstraint conditions. The optimization algorithm find optimal operation value in thesystem. Using different adaptive control strategy of each subsystem, make controlparameters always near the set point. Through system design, device selection, softwareplan and optimization strategy, we developed the computer control of VAV systemoptimization. It can provide directions in actual operation. The simulation andexperiment results show that the optimization method can not only ensure the comfortof the system and can significantly reduce the system energy consumption.