Energy efficiency measures - Industrial - Compressed air - Optimization / United States of America
Case study assignment
Compressed air is supplied to a foundry at the rate of about 20,000 cfm by four standard efficiency compressors, which are individually controlled and brought on or taken off line depending on demand. Fluctuations in demand cause frequent line pressure variations as compressors are manually turned on or off to attempt to keep supply pressure at 100 psig.
Base case
Solution
The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.
Similar project
In 1999 an engine foundry in Indianapolis implemented an optimization project on their compressed air system. Air leakage was reduced, moisture and lubricant carryover eliminated and storage tanks and pressure/flow controllers installed for pressure stabilization.
Real project (262 KB)
Case study assignment
Compressed air is supplied to a foundry at the rate of about 20,000 cfm by four standard efficiency compressors, which are individually controlled and brought on or taken off line depending on demand. Fluctuations in demand cause frequent line pressure variations as compressors are manually turned on or off to attempt to keep supply pressure at 100 psig.
Base case
- Foundry operates 10 h/d, compressors start 1 hour prior
- Four compressors:
- 3,000 hp centrifugal, 12,000 cfm capacity, load factor 90%
- 1,500 hp centrifugal, 6,000 cfm capacity, load factor 88%
- 800 hp reciprocating, 3,500 cfm capacity, load factor 65%
- 800 hp reciprocating, 3,500 cfm capacity, standby, load factor up to 50%
- Air leakage 15%
- Electricity rate is $0.05/kWh
- Supply pressure reduced to 92 psig
- Air leakage reduced to 5%
- Total air demand reduced to 13,750 cfm
- 3,000 hp compressor increased to 100% load factor
- 800 hp compressor maintained on standby
- Remaining compressors decommissioned
- Cost for all improvements is $800,000
- Annual maintenance savings of $70,000
Solution
The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.
Similar project
In 1999 an engine foundry in Indianapolis implemented an optimization project on their compressed air system. Air leakage was reduced, moisture and lubricant carryover eliminated and storage tanks and pressure/flow controllers installed for pressure stabilization.
Real project (262 KB)
