DPR Wraps Up Industrial Cogeneration Project for SP Newsprint

With an aggressive 17-month schedule, project crews are in acceleration mode on construction of a new cogeneration facility for SP Newsprint, a manufacturing company owned by Media General, Knight-Ridder and Cox Enterprises that produces nearly one million tons of newsprint annually through two pulp and paper mills. Headquartered in Atlanta, SP Newsprint also operates a mill in Dublin, GA, which is now the largest 100 percent recycled newsprint mill in North America and third largest in the world.

The Newberg project features the installation of two GE LM6000 Gas Turbine Generators and a pair of Heat Recovery Steam Generators (HRSG) to help increase the mill’s overall electrical generation capacity from 40 megawatts to 130 megawatts.

“Currently, the mill produces approximately 1,200 tons of newsprint paper a day,” said Martin Gavin, project manager for DPR. “Once complete, the new equipment will generate a combined full-fired output of more than 80 megawatts of electricity—some of which the company plans to export to a local utility—and approximately 300,000 pounds per hour of steam for mill operations.”

Gavin explains that the advantage to this cogeneration technology, where electricity and heat are simultaneously produced using a single fuel source like natural gas, is that it provides greater conversion efficiencies than traditional generation methods that may allow thermal energy to be wasted.

Integration of Utility Power Systems

To support the power being generated by the cogeneration project, DPR constructed an expansion to an existing 115kV substation, located on the SP Newsprint property. DPR also upgraded the existing mill substation with a new 115kV main breaker and a completely new lock-out relay system to manage both the existing 13.8kV power distribution system, as well as all new power distribution systems.

“The upgrade was a significant undertaking considering that to achieve full integration we had to interface all of the new systems with existing ones,” said Gavin, who added that DPR planned only two mill shutdowns during the project. The first, in August 2002, included more than 30 piping tie-ins to mill systems and the expansion and tie-in to the existing 115kV substation. During the second shutdown in April, the electrical protective relay systems were installed and the new 115kV substation energized.

DPR also worked with Portland General Electric and Jacobs Engineering in the planning and execution required for exporting excess power from the mill to the local utility grid, which included installation of approximately two miles of off-site fiber optic cable, a GPS satellite clock, radio transmission systems and direct phone lines to the power grid dispatch group. According to Gavin, the infrastructure had to be fully installed, tested and ready by the “first fire” of the gas turbines.

In addition, to manage the many intricate control systems involving gas turbine generators and HRSGs, DPR installed a Distributed Control System (DCS) that oversees the GE turbine-generator controller operations, the HRSG supplemental duct burner management system and all balance of plant systems. The integration of these systems called for DPR to install fiber optic cabling, data cabling and complex communication hubs throughout the mill.

Effective Solutions

To meet the compressed schedule that consisted of an overall mechanical/electrical completion by May 15 and commissioning, start-up and commercial operation by July 1, DPR did some creative building, including self performing a large portion of the civil and structural work. DPR crews placed more than 3,000 cubic yards of concrete for foundations during the summer and early fall of last year. The innovative use of modular steel forming systems for the concrete foundations allowed DPR to exceed estimated productivity rates and further step up the project schedule.

DPR also saved valuable time by having the process piping pre-fabricated in the shop and loaded onto steel pipe bridge trusses prior to being transported to the jobsite rather than the traditional method, where the steel bridges are erected and the piping is installed in the air by pipe fitters. This effective approach not only reduced the erection duration by minimizing welding in the field but also allowed the majority of work to take place in a controlled shop environment, offering increased safety on the job.

Safer Environment

Along with innovative building processes, DPR also incorporated SP Newsprint’s safety procedures into its award-winning “Injury Free Environment” program to create a consolidated safety program to proactively address challenges specific to this heavy industrial project. For example, the location of the project site within the operating mill presented several constructibility issues for DPR and its subcontractors. The site is boxed in by two existing industrial buildings and a filtration plant. Truck and crane movements were also limited by the 115kV power line running adjacent to the site.

Crews received comprehensive safety training throughout the project for working in the 115kV substation, erecting structural steel, and working with heavy equipment lifts and rigging.

The result: “We performed more than 80,000 manhours without a recordable incident,” said Gavin.