|Make Total Condenser Performance™ Your New Year's Resolution|
Did you know that the largest single factor that can affect turbine cycle efficiency within a power plant is the heat transfer within the unit's main condenser? Depending on turbine design, poor condenser heat transfer can cost as much as 10% in additional fuel being consumed, not to mention costs associated with the loss in output should unit backpressure necessitate a derate. Additionally, increased fuel consumption can translate to higher levels of CO2 emissions, which can have both an economic and environmental impact. Factors affecting condenser heat transfer can include; tube-sheet macro fouling, tube deposits and air in-leakage. In addition to the loss of heat transfer efficiency to tube fouling or air in-leakage, fouled tubes also present a heightened risk of tube failure due to factors such as microbiologically influenced corrosion (MIC), under deposit corrosion and physical obstruction damage.
Conco's Total Condenser Performance™ Program, which includes tube cleaning, leak detection and nondestructive testing services, not only improves heat transfer through effective cleaning, but also helps minimize risk of tube related forced outages through effective testing. Achieving the perfect balance of condenser efficiency and reliability is the primary goal of condenser performance engineers, and until now, meant juggling the demands of numerous contractors, and the ensuing headaches as a result. If your condenser performance isn't what it should be, call your friendly Conco representative for a no-nonsense approach to achieving your performance goals in 2011.
|New Re-Sleeving Technology from Conco Saves Finned ACC Tubes|
A frequent problem plaguing power plants with finned air-cooled condenser tubes is erosion of the tube walls due to influences ranging from feed water chlorination to extreme temperature fluctuations and header condensation. Holes in these elliptical tubes allow air to leak into the sealed steam system, resulting in turbine backpressure with a corresponding decrease in MW output. The usual solution is to plug the failed tubes, taking them out of operation. Of course, this reduces the efficiency of the condenser, and if too many tubes are plugged, entire tube bundles may need to be replaced at a cost reaching hundreds of thousands of dollars.
Leaking ACC Tubes at RosebudRosebud Operating Services, Inc. in Billings, Montana, was particularly concerned when leak testing indicated more than a hundred tube leaks were adversely affecting their turbine's performance. "We have more than twelve thousand elliptical finned tubes in our air-cooled condenser," said Dan Gray, Rosebud's Director of Operations. "Made of cold-dipped galvanized carbon steel, each tube is thirty feet long with a two-inch-wide elliptically shaped diameter. In our case, we believe the holes, ranging from ½" to ¾" in diameter, resulted from the exterior water spray system we use to augment two twenty-six-foot-diameter cooling fans during the warm weather seasons. We tried epoxy and gasket material, but without success. Other techniques, such as brazing, had some measure of success in plugging the tubes, but the work was extremely laborious and time-consuming."
Mr. Gray spoke with engineers at Conco Systems, Inc. of Verona, Pennsylvania, who use their FinTech ACC™ air-cooled condenser cleaning system to clean Rosebud's unit on a regular basis. With Rosebud's assistance, Conco began development of a new technology that would eliminate plugging and prove highly successful in restoring finned ACC tubes to service.
After a period of research and development involving various materials and manufacturing techniques, Conco has achieved a successful solution, termed the Conco FinGuard ACC™ ReSleeve system, that employs elliptical shaped tube inserts and couplers that are used on site to bring a plant's ACC leaking or plugged finned tubes back into service. "A small section of the leaking finned tube is cut out using a hand-held grinder," said Mr. Gray. "A new section of finned tube is placed between the cuts in the old tube and stabilized by inserting a 10" long elliptical sleeve. Both joints where the old and new finned tube sections meet are covered with a 4" long elliptical coupler. The sleeve adds internal support while the couplers provide external support. This permanent repair is bonded using a high-temperature RTV (room temperature vulcanizing) sealant."
Both the sleeve and coupler for FinGuard ACC™ are made from thin walled carbon steel tube material and are produced at Conco's manufacturing plant in Verona. The special elliptical shape is formed in a stamping die using a mechanical press. While in this case the elliptical geometry of the sleeve and coupler were designed specifically for the tube geometry at Rosebud's plant, Conco can custom design tooling to produce sleeves and couplers for almost any tube geometry.
"Air in-leakage through condenser tube holes can dramatically affect a power plant's performance," said Mr. Gray. "As the backpressure increased at Rosebud because of this in-leakage, we experienced reduced operating efficiency and increased generation costs. After re-sleeving the bad tubes, we saw our backpressure go from 7 ½ HgA down to 6 ¼ HgA. That's a tremendous improvement. It allows us to use less steam to power the turbine. With our air-cooled condenser, we can now operate at higher ambient temperatures and maintain higher loads for a longer period of time. This new re-sleeving technology is cost-effective and helps us maintain MW output at less cost."
|CONCO @ Power-Gen 2010
|The freezing temperatures in Orlando on December 12-14
couldn't keep the over 1,200 exhibitors and 19,000+ visitors from making the
2010 Power Gen International a success. Visitors to the Conco Systems booth were treated to new 3D animated
videos of our C4S TruFit™ tube cleaner in action, as well as a detailed look at how
our NitroLance™ liquid nitrogen cleaning worked wonders on power plant
air preheaters. Additionally, those
visitors who responded to our email campaign were also the lucky recipients of
a Conco waterproof "Rite-in-the-Rain" notepad!
Power-Gen 2011 is scheduled for December 13-15, 2011 and will
be held at the Las Vegas Convention Center in Nevada. Conco System's booth will be 3818, a 20 foot
booth conveniently located just a few rows from the entrance and adjacent to
the Electric Generating Systems Association pavilion. Plan on stopping by in 2011 to see Conco's
new booth and be on the lookout for our email in early December to register for
your special gift.
Condenser Design, Maintenance & Operation
New Orleans, LA
Jan 20-21, 2011
Energy Generation Conf.
Jan 25-27, 2011
EPRI Heat Rate Improvement
St. Petersburg, FL
Jan 25-27, 2011
Heat Exchanger Users Group
Feb 8-10, 2011
Don't Let Tube Leaks Get You Down!
Conco eddy current testing services are performed for
all utility and commercial customers on all types of non-ferrous tubing
in condensers, heat exchangers and chillers included in the steam cycle,
cooling water systems and/or service water systems.
Eddy Current testing helps to prevent forced outages
by detecting various defects such as pitting, cracking, corrosion,
erosion, grooving, steam impingement and tube-support fretting that
CONCO NDE personnel are fully certified in accordance
with the American Society of Non Destructive Testing (ASNT) SNT-TC-1A
California (Orange Cty)
|Get Your Copy
Request your copy of Total Condenser Performance™ today! The 32 page full color brochure has comprehensive information on achieving the perfect balance of condenser efficiency and reliability through effective tube cleaning, eddy current testing and leak detection services.
This brochure also highlights Conco ProSeries™ tube cleaning systems and Leak Detection Systems as well as the full line of Conco Tube Cleaners featuring TruFit™ technology.