Abstract
Most industrial compressed air systems (CASs) use multicompressor systems to supply air in a common header to be distributed to end users. Screw compressors are reliable and relatively less maintenance-intensive and thus are widely popular. However, CASs with high flow requirements invariably employ centrifugal compressors because of economic power consumption characteristics near the designed flow range. Nonetheless, air requirements vary during production, which forces centrifugal compressors to operate far from the best efficiency point. The resulting nonoptimized CAS wastes energy. This research investigates a meta-control strategy for a CAS that employs multiple centrifugal compressors.
Published literature shows a significant gap in identifying the importance and implementation of load sharing in centrifugal CASs to achieve energy savings. This research develops a generic methodology and model to identify an operating combination of compressors to optimize the power requirement. The model is used to examine the system characteristics of all centrifugal CASs. Finally, the model is applied to an operating scenario found in a large automotive assembly facility during CAS assessment. The model is used to identify possible energy and power savings. This study found that the implementation of a load sharing strategy could save 8.5% in energy and 7.4% in peak demand. This result will also correspondingly reduce the carbon footprint of the CAS.
