Jiangsu Longteng Special Steel Group 25,000 Nm³/h Air Separation Unit (ASU) Intelligent Advanced Control Transformation Project

Background

Jiangsu Longteng Special Steel Group, founded in 1993, is an integrated steel enterprise combining traditional steel production with advanced metal processing. With total assets exceeding 2.8 billion USD and a workforce of over 6,000 employees, the company boasts an annual production capacity of 4.5 million tons of special steel and 5 million tons of deep-processed metal products.

The 25,000 Nm³/h Air Separation Unit (ASU) Intelligent Advanced Control Transformation Project marks another milestone in Longteng Steel’s journey toward smart and green manufacturing. ASUs play a critical role in special steel plants, involving complex processes such as low-pressure molecular sieve adsorption pre-purification, turbo-expander refrigeration, internal compression of oxygen/nitrogen/argon, and full argon distillation. 

Challenges

• Complexity & strong multivariable coupling

• Significant time delays and inertia effects

• Strong external disturbances, making precise control of key indicators difficult

• Real-time responsiveness to downstream steelmaking demands, placing high pressure on operators

Solution

Facing complex challenges in Longteng Steel's ASU, HollySys leveraged 20+ years of industrial intelligence expertise to develop a cutting-edge intelligent control solution. Our three-tiered approach—combining basic control optimization, advanced process control (APC), and automatic load adjustment—ensured seamless integration from Distributed Control System (DCS), and Safety Instrumented System (SIS), to Advanced Process Control System (APC), creating a unified smart control platform.

Results

• 100% automation rate across the plant

• 100% APC utilization, enhancing production and management efficiency

• 21.26% reduction in oxygen venting without increasing raw material consumption

• Lower energy usage, driving economic gains

• 95% decrease in manual interventions

• 60.18% reduction in standard deviation of key process variables

• Flexible load regulation (75%-105% capacity)

• Adjustment speed of 0.1%-0.2% per minute

Since its deployment, the advanced control solution has provided exceptional stability, safety, and reliability, delivering tangible improvements in productivity and profitability. Longte Steel highly commended HollySys’ technical expertise and execution efficiency, recognizing the project team's professionalism and outstanding performance.