Fuzzy Refrigerant Flow Controller for Package Air conditioners Adaptable to Setting Environments

抄録

As an application of fuzzy control technology, the control of refrigerant flow in package air conditioners has been established thus far. However, it is difficult to control refrigerant flow precisely by conventional technologies because package air conditioners have various operational environments, such as machine type or length of refrigerant pipe, among others. Therefore, for high-quality control, it is important to design controllers such that they can adapt to various environments. In this respect, we have established a new controller which has a cascade, two-layer fuzzy control structure, in order to achieve higher refrigerating capacity. The adaptability problem, however, remains unsolved in this controller. In this paper we report on the above controller and the results of two additional attempts to improve the adaptability of the controller. First, we outline the controller which has a cascade, two-layer fuzzy control structure. Then, we improve the controller to make it suitable for practical use. Lastly, we develop a new automatic tuning method for fuzzy control that uses a look-up table, in order to improve stability. We demonstrate the ability of the new controller by experiments and simulation.