Modeling And Control Of BA-Ⅱ Laboratory Central Air-conditioning System

As the information society is developing, intelligent building has a worldwide development, and it obtains great achievements in many actual engineering. Central air-conditioning control system is an important component of BA, whose energy consumption is generally 50% of whole building energy consumed. With the energy shortage of energy supply and the improvement of thermal and humidity comfort and air quality, to reduce the energy consumption to the limit of our ability is a pressing need on the premise of keeping adequate degree of comfort of air-conditioning area. The air-conditioning automatic control system can make a more comfortable indoor environment and a stable operation of installations and the high energy efficiency. From the energy saving and the improvement of indoor air quality, study on the central air-conditioning automatic system has a great significance of intelligent building energy management control. How to optimize the air-conditioning system operation and attain the perfect energy conservation arouses public attention. The key of the design of central air-conditioning automatic control system depends on the perfect design of control strategy.The research object is the constant air volume central air-conditioning automatic control system on the platform of the intelligent building laboratory in Xi'an University of architecture and technology. From analysis of running principle of central air-conditioning system, the mathematical models of chilled water valve and air-conditioning room are established. The PID controller, fuzzy controller and fuzzy-PID controller are designed for the constant air volume central air-conditioning automatic control system and the empirical formula of ZN method is used to tune the three parameters of the PID control. The simulation software-MATLAB/SIMULINK is introduced to analysis this system. By means of contrast analysis of the simulation results of the three control strategies, it is discovered that fuzzy-PID threshold control strategy is better than PID control and fuzzy control. Form comparing with the experimental results, the conclusion is arrived that the established mathematical models of chilled water and air-conditioning room above are right.