Triple 5 will be hosting our first webinar for the new year.  Webinar will take place Wednesday, January 25th at 2:30pm.  More information coming soon.

Date:  Wednesday, January 25th 2012

Time: 2:30pm EST

Registration Link:  (coming soon)

That’s a question not only facing many baby boomers but now the US coal fired power fleet.  The U.S. coal-fired fleet consists of 1,105 units with a nameplate capacity of 342.733 GW, according to a Burns & McDonnell database. Because plant age is often cited as a reason for retirement, it’s useful to examine the fleet’s age. The figure below illustrates the age of each unit in the database, calculated as the difference between 2011 and the year it began commercial operation.

(Source: "Predicting US Coal Plant Retirement", Power Magazine, May 1, 2011)

The average age of all units is 42.5 years and no matter how you look at the numbers, the fleet continues to age. The average capacity factor illustrated below indicates plants under 40 years old are the backbone of the base load fleet and as a plant hits about the 50-year milestone, operation appears to shift to more load-following or cycling operation, as suggested by decreasing capacity factors.  For comparison, the overall average fleet capacity factor is approximately 62%.  However, 455 plants (not including recently commissioned ones, for which capacity factor information was not available) reported an annual capacity factor of 70% or higher.

(Source: "Predicting US Coal Plant Retirement", Power Magazine, May 1, 2011)

What does all this mean for the load following plants?  Tight budgets, no capital monies, low operating margins and reduced staffing levels.  However, the value of these older load following units can be significantly increased if they are ready to run when called by the dispatcher.

Triple 5 has responded to both issues and the value of being ready to run by offering early leak monitoring surveillance for a small monthly fee, no hardware purchases and without a long term commitment.  Load following and tight budget plants can now take advantage of the same technology the larger base loaded plant use to know when a small leak has developed and schedule the repairs and market strategize on their own terms. Knowledge in these times is power and value. Baby boomers have responded by embracing new technologies; now your plant can do the same.

Photo Credit: www.swepco.com

The Fulton Arkansas plant is a new construction for the Southwestern Electric Power Company (SWEPCO). According to the SWEPCO web site, the John W. Turk, Jr. Power Plant will be one of the cleanest, most environmentally responsible and efficient coal-fueled plants in the United States, and the first of its kind in operation in the country. The Plant will use low-sulfur coal and state-of-the art emission control technologies to meet stringent emission limits. And, the plant’s advanced coal combustion technology will use less coal and produce fewer emissions, including carbon dioxide, than traditional pulverized coal plants. The Turk Plant will serve SWEPCO customers in Arkansas, Texas and Louisiana. The estimated completion date for the $1.7 billion 600-megawatt facility is October 2012. Plant construction created more than 1,900 jobs at the height of construction and brings an estimated 110 permanent jobs to the area with an annual payroll projected to be $9 million.

Photo Credit: www.swepco.com

Triple 5 was selected to furnish our AMS 3 system for early leak detection monitoring as part of the Shaw Group scope of the EPC contract.  Babcock and Wilcox engineered, furnished and are in the late stages of installing the boiler island components. Thirty eight (38) Triple 5 non intrusive sounding rods have been welded in place on the cold side of the boiler component walls and awaiting the electronic connections.  As part of the Triple 5 contract, we will provide real time leak detection monitoring for the plant operators using the Triple 5 remote surveillance program. 

We are a “Made in America” company and extremely proud to be a part of this  “Built in America” project.

Figure 1 (Click to Enlarge)

Have you noticed we do not call our system a “Leak Detection System” rather an Acoustic Monitoring System? Yes, of course it detects tube leaks but there are many other abnormalities the AMS can detect. Figure 1 depicts a 60 day trend in which both pluggage and a reheat leak are shown.

Ash pluggage between components can resemble a tube leak on the trend pages. However, the spectrum typically manifests as narrowband spikes as opposed to the leak-associated bell curve. See Figure 2. In addition to the difference in spectra, a leak typically gets louder, resulting in an increased trend as seen in Figure 1. As shown in the figure, the decibel levels associated with pluggage do not typically continue increasing as the levels do with a leak. Also note how the reheat leak noise cycles with load whereas the pluggage noise remains fairly steady.

Figure 2 (Click to Enlarge)

Take advantage of your AMS and utilize it for all it’s worth! Remember, the system can detect tube leaks, feedwater leaks, pluggage, slag, external leaks, stuck sootblowers, leaky poppet valves and more.

Taking the time to think about it, boiler tube leaks are very much like the weather – unpredictable.  We can’t change it.  We can’t prevent it.  Instead, we learn to prepare, manage and adapt our lives to fit the weather daily.

With the help of the weather channel and local meteorologists, we have the benefit of weekly/daily weather forcasts but more importantly, “EARLY” warning of potential damaging storms.

When it comes to boiler tube leaks, Triple 5 and the AMS provide – The “Weather Channel” for Leaks. Combined with Triple 5 surveillance, the AMS provides an “Early” warning of potential leaks and other boiler abnormalities.

Take a snowstorm for example.  We’ll usually get first wind or early warning of a potential snow storm from the local meteorologist.  At that point, we continue to monitor and track the snowstorm in order to prepare (ie trips to the grocery store to stock up on food, getting our shovels in place, etc). Once it arrives, we’re prepared and ready to handle the storm accordingly.

With an AMS, plants typically get the first indication of a leak (prior to makeup or water loss).  Plants then can monitor and track the potential leak real-time allowing time to prepare; schedule staff, have outage material in place, or a trip to the grocery store if necessary.

Can you imagine not having the help of the weather channel or our local meteorologists and waking up on a Monday morning to 10” of snow?

Jerry Journey has a BSME and Masters degree from Ohio University. He worked at AEP for 39.5 years in engineering, supervisory and management roles at AEP Muskingum River, Big Sandy and Corporate Office. His latest role was manager of the plant engineering groups and Director of Boiler Reliability for the 11 state AEP territory. He was also Director of the Boiler Vendor Expo held annually in Columbus, Ohio. He resides in Dublin, Ohio with his wife Beverly and son Lee.

“The Triple 5 System was THE FIRST Indication of a Leak”

Unit :  B&W – 1300MW 3845psi

Location of Leak: Superheat Outlet Section

Facts: The unit is equipped with a 37 sensor AMS Leak Detection System and the plant has a Weekly Surveillance contract with Triple 5. 

Timeline:

March 3: During the Weekly Surveillance check sensor 11 trends at 90dB – a 4dB increase during the past week. 

March 17: The weekly surveillance check reveals an additional 6dB increase on sensor 11 reaching 96dB.  Also noted on 3/10 was sensor 24 reaching  90dB – a 6dB increase.

March 19: The plant calls Triple 5’s 24 Hour Hotline for assistance in analyzing sensor 11,  now trending at 101dB.  The plant reports minimal water loss.

March 24:  Triple 5 reports additional increases on sensors 11 and 24.  Sensor 18 trends at 87dB – a 4dB increase.

March 30:  Unit removed from service at noon as acoustic levels increase significantly.

Plant Follow Up: The initial leak was a tight crack in the middle of an original shop weld.  Six other tubes were washed with leaks ranging from pinholes to 1/4” diameter holes.  The leaks were located 10’ from the left side wall.  Sensor 11 was first to respond.  It is located 20’ below and 30’ in front of the leak.

The tube leak occurred in a 102MW, tangent tube boiler equipped with 20 metalborne waveguides and sensors. The metalborne waveguides are mounted on 4” x 4” waveguide plates that attach to the boiler. The waveguide plates act as a collection point for acoustic activity. The amplitude of the signal increases with the noise generated by the steam leak.

The signal for Sensor 11, located in the Upper Primary Superheater, begins to trend upward and very quickly crosses the alarm threshold (92dB) in a 24-hour period. The signal continues to increase over the next four days and reaches 112dB before shutdown. The 30-Day Trend for Sensor 11 shows the rapid increase as the leak grows. The level remains high, even when the unit is at low load.

The 10-Day Group Trend shows the high readings for the sensors near the leak. Sensor 11 demonstrates the highest response to the leak, followed by Sensor 9, which is located on the same wall. Sensors 10 and 12, the pair sensors for 9 and 11 located on the opposite wall at matching elevations, also show high signals. The high readings, along with multiple sensor involvement help to diagnose the tube leak.

The leak was located on the East Side in the primary superheater outlet tube, 10 tubes from the east about two feet from the top of the superheat assembly.