Compressed air plays an important role in industrial energy transmission. Pneumatic industrial applications require air in a dry, clean and well prepared state for smooth operation. Compressed air dryers which are based on cooling and condensation are called refrigerant dryers. The most important task of a refrigerant dryer is to maintain a constant dew point. The purpose of the master thesis was to develop a control system that would be able to efficiently control evaporation and condensation pressure at all given conditions. The thesis focuses mainly on the control of the dryer. First, the basics of compressed air and PID controller are presented. In the core of the subject we focus on presenting all control components used in the control system, followed by a detailed description of the control program and test results. The controller together with the user interface was developed in TIA Portal environment with PID alghorithm. A robust refrigerant dryer had been developed with precise dew point control at all required loads.
|