Emerson Process Management has been named main automation contractor for a comprehensive, fast-track controls replacement project to improve reliability at the troubled Longview supercritical coal fired power plant in Maidsville, West Virginia. Under the contract, Emerson will remove the existing plant controls and I/O, and engineer and install its Ovation control technology.
The 695 MWe (net) plant was only commissioned three years ago, but has suffered frequent plant trips and low reliability. It is a first-of-a-kind design employing a supercritical FW Benson pulverised coal boiler with a low mass flux evaporator using rifled tubing. The plant was built by a consortium led by Siemens, with Aker responsible for construction. The boiler was supplied by Foster Wheeler directly to Longview. Under the new contract with Emerson it will replace the Siemens T3000 system currently controlling the Foster Wheeler boiler, Siemens turbine, air quality control system, burner management system and other balance-of-plant equipment and processes.
"This is our first collaboration with Emerson," said Stephen Nelson, senior vice president – plant rehabilitation, Longview Power. "We based our decision on their experience managing large, complex projects; successful track record automating supercritical units; and ability to be an open and responsive partner." Another critical consideration, according to Nelson, was Emerson’s ability to complete the project in an accelerated 13-month timeframe, with commissioning slated for June 2015. Projects of similar scope and complexity typically take 18 to 24 months to complete, says Emerson, which has provided Ovation to nearly 100 large supercritical units to date.
Emerson will also provide HART smart instrumentation, including its Fisher FIELDVUE digital valve controllers, Rosemount guided wave transmitters and a number of wireless devices — all inherently compatible with Ovation I/O. Using AMS Suite predictive maintenance software, the plant’s limited staff will be able to easily diagnose, maintain and troubleshoot plant equipment and processes, Emerson believes.
Emerson expects that "providing a more integrated control strategy for the boiler and turbine on a single, unified platform" will "stabilise the unit and greatly enhance reliability." Longview hopes to gain the ability to bid into the regional grid operator’s ancillary services market for such functions as automatic generation control and synchronised reserve, making it possible to capture additional revenue.
Additional revenue is of no small importance to plant owner Longview Power LLC, which filed for Chapter 11 bankruptcy protection a year ago, along with several affiliates, including its coal supplier. The company, a subsidiary of GenPower Holdings, citing design, construction and equipment problems (including delays, boiler tube leaks and the control system issues) combined with adverse market conditions (lower than expected wholesale power prices, low priced natural gas driven by fracking, etc). There have been protracted legal proceedings between Longview and the main power plant contractors. A settlement was reached with Foster Wheeler (currently in the process of being bought by AMEC) earlier this year.
