Metso's automation technologies bring new ways to reduce emissions and save money at Grant Town Power Plant, USA
31 August 2012
Considering the savings in limestone alone the return on investment for the Metso-supplied solution was less than 8 months.
Adding a Metso DNA advanced process control package to Grant Town, a West Virginia plant of the American Bituminous Power Partners, the existing distributed control system (DCS) has resulted in improved performance and lowered production costs. With the advantages of Metso's "Fuzzy Controller", the key result was a nearly 7% reduction in limestone usage over the operating range.
By improving the SO2 capture efficiency, the plant was also able to avoid the considerable cost of installing a post combustion flue gas treatment system. Plant manager Steve Friend commented, "Metso played a significant role in helping Grant Town avoid that cost, and met our expectations of efficient, low cost operation."
The Grant Town Power Plant CFB boilers each have a maximum rating of 400 kpph superheated steam, with coal refuse as the primary fuel.
The study phase conducted by Metso specialists included a physical examination of the boiler and its auxiliaries, control system tuning parameters and the benchmarking of the two boilers, while fuel analysis data from ABPP's contract laboratory provided a history of fuel heat values.
Metso's advanced process control package took over control of bed inventory, O2 control, combustion profile optimization, and fuel / air master controls. In addition to improved combustion, the controls have stabilized furnace wall temperatures to extend the life of the boiler by reducing thermal stress. The Metso DNA Fuel Power Compensator application is also employed at Grant Town to help balance the primary under-fire air with the secondary overfire air to maximize fuel surface contact for better combustion with less un-burnt material exiting the cyclones.
American Bituminous Power Partners, LP is the co-owner (50%) of the Grant Town Power Project in Grant Town, WV with Edison Mission. Grant Town is an 80 MW waste coal power facility in Marion County, West Virginia. The power is sold to Alleghany Power Systems ("APS") under a 35-year contract. American Bituminous supports a fully competitive power market in which exiting commitments are honored. The Grant Town Power Project has permits for waste coal mining and reclamation.
The Grant Town project was developed under the Public Utility Regulatory Policy Act (PURPA) of 1978. American Bituminous is a partner in West Virginia's electric energy infrastructure and plans its continued support to the State of West Virginia well into the future.
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