Systemic Leak Reduction & System Control Optimization

Leakage in compressed air systems is a common problem and can lead to significant wastage. Due to the high pressure in the system, even a small leak can result in large amounts of compressed air being lost. Moreover, leaks may be more difficult to detect as compressed air does not leave physical clues like leaking water or oil, and the hissing sound – which is the most easily detected sign of an air leakage – may get hidden in the background noise of the manufacturing environment. The leak rate on an unmanaged compressed air system can be as much as 40–50%. The importance of leak reduction is not limited to energy savings. Leakage can also result in equipment malfunctions and impact product quality, reduce the equipment life-time and increase maintenance costs. Consequently, it is particularly important to implement a systemic leak detection and elimination programme.

Leaks can be detected by relatively simpler measures like listening and looking for visiual indications (such as bubble creation on applied soapy water). More sophisticated, but more complete, leak detection can be achieved through the use of ultrasonic leak detection equipment. It is important to note that the majority of system leakage will be at the point of use and not in the distribution piping. Gains in reduced leakage almost always justifies the investments in leak detection and elimination investments.  

As covered in detail here, the system controls also play an important role on the efficient operation of the compressed air system. In cases where such control systems are not automated, their fine-tuning should be performed in a systemic fashion.

Development Status Products
Commercial

Systemic Leak Reduction & System Control OptimizationCosts & Benefits

Parent Process: Compressed Air Systems
Energy Savings Potential

When combined with optimized compressor system controls, systemic leak management can offer the following improvement potentials:
• 20% for low efficiency base cases;
• 15% for medium efficiency base cases;
• 10% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for diffierent countries is estimated as following (UNIDO, 2010): 

  Final (GWh/y) Primary (TJ/y)
US 7073 77658
Canada 1867 23258
EU 6190 58158
Thailand 986 9925
Vietnam 444 6336
brazil 1814 20247
CO2 Emission Reduction Potential

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 4263
Canada 928
EU 2699
Thailand 512
Vietnam 218
brazil 265

Costs

Estimated typical capital costs for systemic leak management, combined with system controls, for different system sizes (S) are:
• US $1250  for S < 37 kW;
• US $3000 for 37 kW < S < 75 kW;
• US $5000 for 75 kW < S < 150 kW;
• US $5000 for 150 kW < S < 375 kW;
• US $5000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following: (UNIDO, 2010)

US 14.4
Canada 15.1
EU 17
Thailand 5.4
Vietnam 5.4
brazil 6.1

Parent Process:
Energy Savings Potential
CO2 Emission Reduction Potential

N/A

Costs

Systemic Leak Reduction & System Control Optimization Publications

Page Number: 

52-63