YEI Engineers, working as Electrical, Mechanical, and Control Consultant Engineers provided specifications, designs, construction supervision and start up assistance for a 50 Megawatt (MW) gas-turbine cogeneration project for Unocal's Wilmington, California Refinery. This 36 million dollar, fast track project was designed and constructed between October of 1986 and February of 1988.

     YEI's design covered specifications for all major equipment, including the 60,000 horsepower gas turbine, the 50 MW electrical generator the CO and NOx pollution control equipment, the 300,000 lb/hr heat recovery steam boiler and the medium-voltage switchgear lineups and transformer. In addition to designs for the new cogeneration plant, YEI provided complete engineering to convert the refinery's loop-type, 34,500 Volt electrical distribution system to a radial-type system, including a new, central 34.5kV switchgear substation.

Power cogeneration project

     The use of direct-coupled generator, along with a heat recovery boiler, converts the turbine's rotational energy to electricity and the turbine exhaust's heat to steam. This allows the refinery to meet its electrical and steam requirements at a much lower cost than the conventional methods of purchasing electricity from a public utility, and producing steam in a conventional gas fired boilers. The plant also has the capability of running on refinery waste gas, which would normally be flared off.

     In addition to saving energy, this project if environmentally significant, because emissions of carbon monoxide, nitrous oxides and hydrocarbons are substantially reduced through the use of state-of-the-art catalysts, ammonia injection, and turbine water injection. Plant safety is also enhanced since the electrical output of the generator is sufficient to carry the entire refinery electrical load during utility outages, preventing costly and sometimes risky refinery upsets.

     The project was commissioned in February 1988 and was reliably on line within only two weeks from the initial start up attempt, an unusually short time for a plant of this size and complexity. The cogeneration plant continues to operate at over 99% availability, attesting to the quality of YEI's engineering achievement.