Case story > Delong Steel mill, Xingtai, China.

Because everything in life needs to be in balance.

Chinese steel mill improves energy efficiency on compressed air

At Delong Steel mill in Xingtai (China) compressed air was recognized as expensive utility.

Sarlin brought in their 60 years of experience in compressed air and reduced 13% of mill’s compressed air electricity use.

Saving was achived with Sarlin Balance Smart Manaagement System by reducing network pressure level and applying energy efficient control strategy for existing compressors. Project was lead by Sarlin’s chinese sales partner Greenstrem Network as an energy management contract (EMC) project.

Delong Steel Xingtai mill produces 3 Mt of hot-rolled steel coils annually.

Compressed air demand for mill production is 500 – 550 m3/min in total. Compressed air is produced with five turbo compressors located in one compressed air station. Quality requirement for compressed air varies in end use points. There are separate supply lines for dry and wet compressed air. Annual energy use for compressed air production is 33 000 MWh and cost 2.5 M€ at China’s electricity price.

Customized solution for Delong Xingtai steel mill
Sarlin Balance Smart Management System was installed to take control of pressure level in end user points and to control compressors at maximum efficiency. Sarlin Balance system reads pressure from demand side of network in wet and dry air supply lines and three remote locations in mill production areas. Compressed air use in the production is monitored and compressors air output capacity is controlled accordingly. Sarlin Balance automatically adjusts compressor output capacity to cover the demand of compressed air in end user points.
Sarlin Balance saved 13% energy cost after a short time 
Electricity saving is result of lower network pressure and more efficient compressor control. Sarlin Balance monitors status of turbo compressors constantly. Turbo compressors efficient Inlet Guide Vane control capacity is fully utilized while wasting of air through Blow-Off Valve is reduced to minimum. Unloading of turbo compressors is used when applicable, providing that there is other control capacity available. Pressure level reduction saves air usage in production and reduces power requirement of compressors. Achieved energy saving in total is 13%, which means 340 000 € annually.

Electricity saving of compressor power is 13% and pressure level was reduced 0.4 bar. Saving is verified by 2 week measurement Baseline and Sarlin Balance measurement periods.

Sarlin Balance brings much more benefits other than energy saving

Manual operation of compressors was replaced with automation technology of Sarlin Balance. There is no more delay in starting compressor according to production demand. Reliability and quality in compressed air production was increased. 

Moreover, compressor station operators are delighted much Sarlin Balance helps with daily operation. User interface is easy to operate, and all data needed for reporting is available at one glance.