Alabama Power upgrades 90 damper drives on 720-MW generators
March 29, 2010 - Alabama Power has modernized drives for most major air dampers on two, coal-fired generating units - 90 drives in all. Installations took place at the company's 25-year old, James H. Miller, Jr. plant near West Jefferson, AL. Each unit has a nominal generating capacity of 720 MW.
After a comprehensive engineering study, Alabama Power decided to purchase Intelligent ContracTM electric actuators from ABB. Added to ABB's actuator line in the 1990's, these digital positioners come in a series of models with torque ratings up to 12,000 ft-lbs.
A central (DCS) computer sends each drive a specific setpoint signal computed to position each damper for optimum boiler operation and combustion efficiency.
High maintenance levels with the old drives, plus growing scarcity of replacement parts, provided plant engineers with ample economic justification to upgrade the actuators. The new drives offer significantly more precise and responsive damper positioning. According to industry research, improving excess O2 control 0.5% with tighter FD/ID fan damper positioning can result in 0.15% heat rate improvement. For the two Alabama Power boilers, that equates to $350,000/yr in fuel savings. The replacements have also drastically reduced maintenance costs for drives at the plant, which have a 10-year service interval.
A separate Power Electronics Unit, panel-mounted in the photograph, provides the intelligence for the Contrac actuator. Microprocessor-based and configurable, this unit receives a DCS setpoint signal (HART communications protocol) in the range of 4 to 20 mA DC, calling for a correct damper opening for optimum plant operation. It feeds back 4-20 mA signals to the DCS, representing actual actuator positions.
With rapid resonse to the setpoint signal, the electronics unit uses advanced frequency converter technology to independently vary the drive's torque or travel speed as it modulates damper position. The actuator's motor is stepless, and increases or decreases the torque smoothly as it moves the damper to a new position with an accuracy of 0.1%.
Additional functions provided by the electronics unit include logging maintenance and service information as well as predictive diagnostics to warn of critical maintenance needs.
ABB is a leader in power and automation technologies that enable utility and industry customers to improve their performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 107,000 people.
MORE CASE STUDIES
FIPA delivers machine handling for Foilpuller automated sheet metal system
Featuring cycle times of 30–45 seconds, the CNC-controlled Foilpuller with FIPA EOAT and vacuum technology automates the film-removal process for...
Casa Systems chooses Omnify Empower PLM software to manage engineering products
Casa Systems was growing and they needed to find a solution to support formal engineering change control processes in order to eliminate issues...
Carolina Color chooses Liad to automate color delivery product line
Carolina Color faced an interesting business decision arising from the launch of two new coloring technologies. Carolina Colors decided to find an...
Rotork provides automated shut-off for heating pipelines in Northern Sweden bridge
Opened in 2014, the 2.1 kilometre bridge also carries two 400 mm diameter district heating pipelines which are now protected by an emergency...
Lakeview Farms uses Leading2Lean's CloudDISPATCH system to cut downtime by 34 percent
Six months after implementing Leading2Lean’s CloudDISPATCH system, however, Lakeview Farms experienced a 34 percent decrease in line downtime, a...
Endress + Hauser earns IACET accreditation for IACET Continuing Education Units (CEUs)
Upcoming classes in 2017 which offer CEUs at Endress+Hauser include I-101 Basic instrumentation in January, March, June, and September in...
Empowering the Workforce to Control the Future of Automation
By Peter Martin, Schneider Electric Process Automation
Connected products are expected to approach 30 billion by 2020, with utilities,...
Okuma to highlight automated machining advancements at NTMA Plant Managers Roundtable
The NTMA Plant Managers Roundtable at Modern Industries in Phoenix, Arizona will discuss the various types of automation devices that make...
Emerson to help EPH Lynemouth Power automate biomass-fueled power plant
When the conversion is complete in late 2017, the plant, near Newcastle in the United Kingdom, will be fueled by approximately 1.4 million tons of...
Gilman Precision announces Donald Hunkel as new application engineer
In his current role, Don’s objective is to assist customers in overcoming engineering challenges and produce customized products that achieve the...