Emerson Process Management and Mitsubishi Power Systems Americas (MPSA) have successfully completed a dual-fuel conversion project that allows a plant to work using natural gas or oil.

The 320MW Termocandelaria plant is a two-unit facility in Cartagena, Colombia.

The project involved the conversion of two Westinghouse 501F gas-fuel turbines to dual-fuel operation, which enables the plant to increase start up reliability with reduced costs.

It also helps Colombia, which in times of drought cannot meet its power demand using its predominant source of power – hydroelectric.

Termocandelaria plant manager Miguel Angel Perez Ghisays said the dual-fuel conversion has enabled the plant to generate megawatts on request and become a dependable back-up energy source that helps grid stability.

Emerson, in collaboration with MPSA, established a new control plan for dual-fuel capability that involved logic for water injection, fuel oil and fuel gas systems.

It shifted the existing gas turbine controls to its Ovation expert control system from the WDPF distributed control system.

The migration involved transforming the old logic to SAMA logic to allowing the facility to easily alter control schemes according to varying conditions.

MPSA managed the dual-fuel adaptation covering the new combustion system elements and oil and gas fuel supply systems that include Emerson instrumentation and control valves in addition to electrical and civil design of the plant machinery for oil and water treatment and storage machinery.

To streamline the fuel transformation process and maximise output of the unit, water-injected diffusion flame combustors (combustor baskets, fuel nozzles and transition pieces) were provided.

MPSA’s new dual-fuel system, which uses a duplex liquid fuel nozzle to enhance start-up low load particulate emissions and opacity and eliminate the necessity for a flow divider, was also included in the retrofit.

To ensure high starting dependability, purge air systems as well as Mitsubishi’s high energy ignition system were also supplied.