Simulation Research On Fan Control Of VAV System In Office Buildings

With the improvement of living standard and the development of technology, air conditioning systems have become an important part of daily life, and their energy consumption has drawn more and more attention. Gradually, variable air volume (VAV) air conditioning system became the trend of air conditioning system because of its great potential in energy conservation. As a strong coupling and nonlinear system, VAV system can hardly meet the user's requirement.Based on existing research, the simulation model of VAV system has been set up with Simulink, which establish the foundation of the simulation. With fuzzy theory and the theory knowledge of regulating air volume, a fuzzy controller is designed, which is used to control fan. Then the model and controller are used to simulate.Finally, experimental measurements have been taken at Technology laboratory in Guangzhou University. Voltage, current, frequency of fan have been measured. Also, temperature, relative humidity of indoor air and frequency of fan have been measured when the system was operating in different original temperature and relative humidity.The simulation results demonstrate that the room without terminal heater can be kept in the same condition by tuning the parameter of terminal controller. VAV system with fuzzy controller can keep temperature and relative humidity in comfortable zone.The experimental results declare that VAV system used fuzzy controller in fan can lower the indoor air temperature faster than the one used PID controller, it uses approximately 30% less energy in fan. With the increase of original relative humidity, relative humidity of indoor air is higher and worse in stability after indoor air temperature is lowered to 26℃.