GDF SUEZ North America had plans to complete a blended fuels project for one of the main boilers at their Golden, Colorado power plant (primarily serving the Molson-Coors Brewery). The boiler was being fueled by coal, but the plan was to convert it to natural gas, or a combination of the two fuels.
Behrent developed a $3.5 million budget for the project. When the preliminary engineering package was ready, EPC bidders were invited to a pre-bid meeting and project walk, and were also given a chance to individually present their bids to the evaluation team.
Because of Behrent’s involvement in the preliminary engineering phase and familiarity with the project requirements, plant management then retained Behrent Engineering to execute the detailed engineering phase of the project.
Behrent was also asked to develop detailed subcontractor bid packages and assisted in the bid evaluation process.
The project had three main objectives:
- Install natural gas piping.
- Replace flame safety controls (Norpak panel).
- Replace combustion controls (Fisher AC3).
To accomplish those objectives, the project included the following scope of work:
- Install the new flame safety control panel near the Norpak panel. Use redundant Rockwell Automation Control Logix 1756-L72 PLCs for the new panel. Plan to convert the Norpak panel to a marshaling cabinet. Save and reuse all field instrumentation and wiring.
- During shutdown: Cut over to new flame safety controls. Replace half of the pulverized coal fuel nozzles. Inspect the condition of existing gas fuel nozzles.
- Install a new 10-inch gas main to Boiler 5, including main gas stop valve, flow, and pressure controls; block and bleed valves to each gas burner; and combustible gas detectors.
- Hot tap the existing main gas header while the boilers continued in operation.
- Install the new combustion control PLC system near the Fisher AC3 racks. Use Rockwell Automation ControlLogix 1756- L72 PLC. Add marshaling terminal blocks to existing Fisher AC3 racks. Prewire the new PLC to marshaling terminal blocks. Save and reuse all existing field instrumentation and wiring.
- Connect all new gas line valves and instrumentation to the new PLC panels.
- Update the iFIX SCADA system to include the new gas line valves and instrumentation and to interface and gather data from the new PLCs.
- During winter shutdown: Cut over to new combustion controls. Replace Fisher AC3 operator stations with new Rockwell Automation PanelView Plus 6 15-inch color touch screens. Tie in new gas line to each existing gas nozzle. Replace remaining pulverized coal fuel nozzles.
- Develop detailed checklists for panel checkout and software testing.
Fuel flexibility was a primary driver of this project, and Boiler 5 is now capable of firing the following fuel combinations and percentages:
- 100% coal (from western Colorado, primarily bituminous)
- 100% natural gas (from Xcel Energy)
- 50% to 100% coal, blended with natural gas
Project Cost and Schedule.
Due to the detailed planning and coordination used on this project, the project was completed on time and approximately 10% under budget.
Ultimately, this project was awarded Power Magazines “2015 Reinvention Award” (formerly known as the Marmaduke Award).