CoGen Upgrade Project

New Jersey September 2019–November 2020

Riggs Distler and our joint-venture engineering partner completed upgrades to three gas turbines and a hot water waste generator at an important electrical generation site in central New Jersey. Installing the upgraded units will lower the owner’s maintenance costs associated with the unreliability of older units and planned shutdowns, lessen the facility’s impact on the environment, and allow the plant to perform more efficiently. The new units will each produce 5.7 MW of electricity.  

Both our Heavy Industrial and Electrical Generation teams contributed to the success of this project. Services included:

  • Demolition and replacement of combustion generator foundation slab (at grade) and auxiliary housekeeping pads
  • Structural Steel Work: Removal and replacement of steel support structures for filter houses below and above the roof line, replacement of lubricant oil cooler structures.
  • Extensive roofing work to allow for new piping, steel, and electrical work to be completed
  • Removal and replacement of the three existing 4.7-MW combustion turbine generators and heat-recovery hot water generators
  • Removal and replacement of ducting, bypass stacks, high-temperature hot water code piping, high-pressure and low-pressure gas piping, generator lube oil piping, and miscellaneous piping systems for air, CO2, non-potable water, and fuel oil.
  • Demolition and replacement of three 4.7-MW turbines generators with new 5.7-MW turbine generators and new hot water heat recovery generators controls (including burner management and combustion systems).
  • Installation of new variable speed drive for motor within the new turbine generators.
  • Demolition of existing Balance of Plant Control and installation of new, state-of-the-art Balance of Plant Control, instrumentation, and communications systems.
  • Demolition and replacement of three out-of-date motor control centers with new control system capabilities.
  • Installation of three continuous emission monitoring systems, including mechanical installations of new sample tubing from each stack.
  • Demolition and replacement of aging Uninterrupted Power Supply Systems (UPS).
  • Over 50,000 feet of control cabling and 20,000 feet of power cabling installations with associated conduit.

This was the first project Riggs Distler performed as a joint venture and Engineering, Procurement and Construction contract performing a design build project.

Challenges Overcome

Several large pieces of equipment, some in excess of 55,000 lbs., needed to be placed and installed within the functioning generation facility, and careful planning and logistics were key to ensuring each phase of the project proceeded efficiently. Our team used a gantry system to remove equipment safely and securely, and close communication between plant staff and Riggs Distler’s management and crews allowed us to proceed efficiently. This project often required numerous staff working within a small area, which posed a significant challenge due to the COVID-19 pandemic. Riggs Distler took extra precautions, including always providing correct PPE and practicing social distancing to keep our team safe.

Results Delivered

The system and equipment upgrades Riggs Distler delivered allowed the client to continue their operations with less maintenance and reduced costs due to unplanned outages, while also increasing the generation capacity of the existing units. The efficiency afforded by the upgraded equipment will also reduce the facility’s environmental impact. Despite a challenging work site and a public health crisis, Riggs Distler’s team proved its ability to adapt to adversity and deliver results for our clients.