Skid-Mounted Air Station for a Shipyard Reaches 61% Transmission Efficiency

Shipbuilding depends on compressed air at almost every stage:

• steel cutting, welding and painting;
• outfitting, and sand blasting for rust removal;
• pneumatic tools;
• precise control of pneumatic instruments;
• hull tightness testing.

Demand is large and highly variable, following the build and repair schedule, and air quality matters for both instrument air and high-specification coatings.

A shipyard decided to build a highly efficient, fully digital compressed air station. It had three goals: lower energy use over the whole lifecycle, intelligent operation in every scenario, and full data visibility.

The station combines three elements:

• Two-stage compressors. Three SIND DUALLUBE-VPM series two-stage, permanent-magnet variable-speed screw compressors form the base. Two-stage compression lowers specific power, and the PM variable-speed drive keeps efficiency high at part load as well as at peaks.
• Skid-mounted modular station. Compressors, dryers, filters, air receivers and controls are pre-integrated into standard skid modules and factory-assembled before shipment. On site, the station needs little more than a power connection to start up. The modular layout leaves room to add units as capacity grows.
• Digital management system. Pressure, flow and dew-point sensors at the end of the network feed a control system that interlocks the three compressors according to load. It holds network pressure within ±0.02 MPa of the usage set-point and monitors vibration and temperature for early fault warning.

Air treatment combines efficient oil removal with refrigerated and desiccant drying in two stages.

The station exceeds the Grade-1 energy-efficiency standards.

Measured after commissioning:

• 61.02% overall station transmission efficiency.
• Oil content below 0.01 ppm with a stable pressure dew point, meeting the requirements of ship control instruments and ballast-tank coatings.
• Network pressure held within ±0.02 MPa.
• Unattended running with mobile-app monitoring.
• Detailed energy reports to support management decisions.