Black Dog Unit 6 Simple-Cycle

Black Dog Unit 6 Simple-Cycle Project
Burnsville, Minnesota
Client: Xcel Energy

Project Highlights:

Plant type: simple-cycle
Fuel: natural gas
Size: 214.8 MW (net)
CT Supplier/Model: GE / 1 - 7FA.05

Project Description:

The Black Dog Generating Station is located in Burnsville, Minnesota. Unit 6 is a natural gas-fired simple-cycle with a net output capacity of 214.8 MW and employing GE 7FA.05 combustion turbine (CT) technology. Sargent & Lundy’s scope started in January 2016, with detailed balance-of-plant (BOP) design, including civil, structural foundations and piles; structural steel additions and modifications to existing turbine building steel; mechanical piping and equipment; electrical auxiliary power system and instrumentation and controls. Additionally, the scope required preparation of technical equipment procurement specifications; development of multiple installation specifications (structural foundations and piles, structural modifications and enhancements to existing steam turbine pedestal, structural steel and architectural, mechanical systems, and electrical and I&C systems); bid evaluations; and specification conformance.

The new combustion turbine generator (CTG) was installed on the existing Unit 4 steam turbine generator (STG) pedestal in the existing turbine building, which was modified to support the new CTG. The new CT exhaust system, including transition duct, expansion joint, and stack with silencer, was installed where the former Unit 4 pulverized coal-fired boiler was demolished. The exhaust system penetrates the boiler building roof and is top-supported from the existing boiler support steel. A new natural-gas pipeline was brought to the site to support both the new simple-cycle unit and the existing 1x1x1 combined-cycle unit. Unit 6 achieved commercial operation in April 2018.