Study On Variable Flow Intelligent Control For Central Air-Conditioning Chilled Water Systems

With the development of China’s urbanization, the increasing number and sizeof buildings, the rising of building energy consumption. The centralair-conditioning system, the essential infrastructural facilities of building, has alsobrought about gigantic consumption of energy while providing comfortableenvironment for people. According to relevant data statistics, the central airconditioning energy consumption accounts for about50%of the total energyconsumption of building, the energy consumption of the water system of thecentral air conditioning for60%to80%of the energy consumption. Therefore, thecentral air conditioning system control research has become one of the hot spot forcontrolling project.The central air conditioning freezing water system is a typical nonlineartime-varying, large inertia, complex system, which is hard to establish practicalmathematical model. The conventional PID control system depend more onmathematical model, and the PID regulation performance parameters of settingwith it, In contrast the chilled water system of time constant, adjust thetime-consuming and difficult to obtain satisfactory control effect. Therefore, basedon the study of fuzzy control and the particle swarm optimization algorithm, andon the basis of fuzzy control technology, the PID control technology, the particle swarm optimization algorithm is proposed, which combines a fuzzy self-tuningPID control strategy. Design the central air conditioning freezing water systemadaptive fuzzy PID controller, not only keep the PID control the advantages ofsimple, high precision, also has the fuzzy control adaptability, and robust features.Research is based on particle swarm optimization controller parameters, the use ofparticle swarm optimization algorithm has been designed to quantify the factorsand the controller has been optimized scale factor, the final design of the controllerof a simulation study. The simulation result shows that this design controller hasbetter control effect, making the frozen water return water temperature in the basicstability within the scope of the set.