14.7 MW Gas Turbine CHP Project – Algonquin Power

Windsor Locks, CT    

  • Contract value:                  1,024,195
  • Total Man hours:                    10,702
  • Recordable injuries:                      0

 Highlights & Challenges

Would you fit? Skilled 6G welder needed to work in space with high wind, elevation and 18" clearance.

Would you fit? Skilled 6G welder needed to work in space with high wind, elevation and 18″ clearance.

  • First use of OTSG technology in this country
  • Lack of perimeter access and congested work space
  • Extremely fast track timeline
  • Steam lines remained at full pressure and high temperatures
  • Strict environmental regulations due to proximity of river

 Project Accolades

Winner of two construction industry mechanical awards from Associated Builders and Contractors:

  • Excellence Award from the Connecticut Chapter
  • Excellence Award from the Rhode Island Chapter

 “I wish to commend you for an outstanding job performance during our recently completed re-powering project. This project was constrained by many obstacles such as a tight schedule, limited space and the challenges presented by a parallel engineering and construction timeline. Your highly skilled staff adapted well and were vital in identifying problematic issues and offering alternative solutions to keep the project advancing. The high priority that your company places on safe work practices, its highly skilled workforce and high quality work are the key reasons Notch was selected for this project and you didn’t disappoint.”                                                                                     James W., Plant Manager, Algonquin Power


 Project Overview

The Algonquin Power cogeneration plant supplies steam and electricity to the Paper Mill.  A power upgrade was needed due to constraints on the local power network. There was $7 million available from a State grant if the company could produce power  by the deadline, a mere 14 months away. The company had a new 15 MW combustion turbine generator and a 50,000 lb/hr once through steam generator to install.  Significant front loading of design and work planning was necessary with the entire Project Team.  Beyond the usual concerns of budget, time and production, the plant operates on a restricted footprint between the Connecticut River, a canal and an active train rail.  Its narrow one lane road around the plant, was further restricted by an existing pipe bridge. The project  required modification of this pipe bridge as the new turbine pieces lacked clearance.  The tight working conditions required cooperative partnerships, creative real time solutions and a well executed, unified work plan.

Notch’s Scope Summary

The Notch task was to connect the new equipment with a new network of piping systems within the existing infrastructure. The new turbine location was in the middle of the existing plant. The new piping had to be woven in amongst the web of the operating system. This involved high and low pressure steam piping, high pressure boiler feed water piping, an anhydrous ammonia system, high and low pressure fuel gas piping, ultra-pure water systems and equipment piping.  Most piping components were prefabricated at our shop, assembled on site and rigged in place within the main infrastructure. The high pressure steam system has an in-service temp pressure of 900psi and 600°F and was installed with 100% x-rayed welds. Taking advantage of a scheduled plant outage, the existing pipe bridge was modified to provide rigging access for the new gas turbine and HRSG.

Project Team

Client:  Algonquin Power at the Ahlstrom Paper Mill

Engineering Firm: R.G. Vanderweil Engineers

General Contractor:   Cianbro Corporation