Energy Efficiency of Compressed Air Systems

Compressed Air (CA) systems have a significant impact on the energy consumption and efficiency of manufacturing systems. These may be composed of a single compressor or include several compressors that work together in a logical manner. Compressors with fixed or variable drive systems have dynamic energy consumption profiles. In addition, they require complicated logic to control multiple compressors as a system. The control system reacts to the flow and pressure of the air output and determines which compressors need to be loaded and which ones to be unloaded.This paper provides an overview of techniques to model energy consumption as well as various approaches used to control the CA system. A state-base modelling technique is used to develop a simulation model that includes both fixed and variable speed drive compressors. This has been applied to analyse different scenarios for controlling the system. An industrial case study including two variable speed and one fixed speed drive compressor is used to demonstrate the dynamic of energy consumption of the system and the validity of the proposed model.