Project Description


This plant is a 2 x 1 combined cycle facility, with two GE Frame 7EA combustion gas turbines fitted with Nooter Ericksen HRSGs (w/duct burners) feeding an ABB VAX steam turbine. The plant was originally configured as a 220 MW cogeneration station, providing 900 psig and 250 psig steam (via turbine extraction) to support operation at a neighboring refinery. Closure of the refinery resulted in unused steam capacity.

Our Solution

Imperia evaluated potential uses for the unused steam. This included both Power Augmentation (steam injection into new combustors) and installation of a second condensing steam turbine. The resulting analysis indicated that these projects will yield a 34% increase in MW output and a 13% improvement in heat rate.

Imperia provided engineering, procurement and construction management for the new Siemens STG-600, SPX condenser and evaporative cooling tower, including integration of the STG controls with the Emerson DCS. The project was placed in service June 1, 2016 to support summer peak loading.


  • Specification / procurement support for steam turbine generator, condenser, cooling tower
  • Steam turbine generator layout, including associated piping and electrical subsystems
  • Structural design of cooling tower basin and steam turbine generator foundation and pedestal
  • Power delivery upgrade and 230 kV grid connection at 2×1 cogeneration facility
  • Evaluated plant auxiliary equipment; condenser expansion options and completed preliminary engineering for the recommended turbine configuration
  • Revised heat balance: 12% increase in MW output and 13% improvement in heat rate
  • Detailed design and construction packages
  • Prepare all civil / structural, mechanical, electrical and instrumentation & control drawings used for construction
  • Prepare multi-discipline installation specification; including bid review and recommendation of selected vendor
  • Construction management; start-up testing and commissioning