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.
| Original language | English |
|---|---|
| Article number | 139630 |
| Journal | Journal of Cleaner Production |
| Volume | 433 |
| DOIs | |
| State | Published - Dec 25 2023 |
Funding
The US DOE has supported compressed air assessments for manufacturers through different programs. Many facilities have realized considerable energy savings and have published case studies on the DOE website. CAS control optimization is one of the advanced strategies and has been investigated in many of the assessments (DOE (EERE), 2023). Through the DOE, Cummins conducted a compressed air audit and realized a 40% reduction in CAS costs even with a significant increase in production (Wogsland, 2001). A comprehensive review of industrial compressed air energy use and energy savings found that control-related energy savings in the field can vary from 0.8% to 10% on average (Saidur et al., 2010). Control-related opportunities exist in 20% of facilities that have a CAS (Radgen and Blaustein, 2001). Many authors studied simulation and control methods for complex compressor networks to refine or propose new approaches to improve CAS energy performance. These studies are summarized in Table 3 along with their advantages and limitations. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
Keywords
- Centrifugal compressor system optimization
- Centrifugal compressor systems
- Compressed air operations
- Compressed air optimization
- Compressed air systems
- Compressor specific energy
- Energy efficiency
- Load sharing
- Manufacturing energy savings
