Chiller Tube Cleaning-A Necessary Preventative Maintenance Task

In 2007 on a man-made island off the coast of Qatar, the world’s largest chiller plant came online. The Pearl Qatar’s mechanical building is packed with fifty-two chillers each over two thousand tons providing an astounding 130,000 tons of cooling to the island’s residential and commercial buildings. In a country where summer temperatures hover around 120° F, the water-cooled chiller plant at The Pearl Qatar never slows down and neither does the maintenance staff.

Your team may not be working on chillers that cool the million dollar homes of oil tycoons, but to keep your chiller working efficiently, it needs regular maintenance and cleaning just like the chillers at The Pearl Qatar. Chiller manufacturers have recommended maintenance tasks that include periodic cleaning of the chiller and condenser tubes. Chiller tubes make up the “circulatory system” of the chiller and, just like when humans veins and arteries clog, when tubes are blocked things go bad.

As chilled and condenser water flows through the machine, the tubes allow the heat extracted from the building to be transferred between the various water and refrigerant loops and finally dispersed to the atmosphere. A chilled water system relies on the effective transfer of heat to cool the building without overloading the chiller and causing it to run longer than it should. If the heat transfer through the tubes is inhibited because of a build-up of scale, sediment, or slime, the chiller works harder to move heat and overcome the system inefficiencies created by the dirty tubes.

The accumulation of contaminants occurs in every chiller no matter how frequently the chiller is serviced or how clean the water inside is. This buildup in the pipes is called “fouling” and engineers take it into account during system design. But when fouling accumulates thicker than what the designer assumed, the overall system loses capacity and uses more energy compared to a clean chiller.

The air conditioning industry publication the News in their article Maximizing Chiller Efficiency warns that tube fouling can reduce “…heat transfer efficiency 15 percent or more.The situation can be compounded by the formation of permanent scale or iron deposits…If this occurs, an additional 10 to 20 percent loss in heat transfer efficiency may result. To fix the problem and restore lost efficiency, an unscheduled shutdown and physical cleaning of the chiller may be required.”

Even the major manufacturers advise cleaning the chiller tubes as part of normal maintenance. In Carrier’s operation manual for their AquaEdge® High-Efficiency Centrifugal Chillers they suggest “the following must be done on a yearly basis…shell and tube heat exchanger tubes [within the chiller] must be cleaned.”

A large water-cooled chiller has hundreds of tubes and each one must be individually cleaned. For a chiller plant like The Pearl Qatar, there are literally tens of thousands of tubes totaling many miles in length that need cleaning. Tube cleaning in large chillers does not need to be a daunting task. The proper tools can make the job quicker and easier with minimum mess around the chiller and on the technician.

A rotary tube cleaner like the RAM-PRO-XL® Chiller Tube Cleaner with TubeGuard®-XL provides maximum cleaning and corrosion protection for smooth and internally enhanced chiller tubes. The RAM PRO XL® is a portable cleaning machine with built-on wheels so technicians can quickly move the unit around the facility during preventative maintenance. The machine works with Goodway’s flexible shafts and brushes each in a variety of lengths and diameters to suit your tube cleaning requirements. If your facility has different sized chillers needing different shaft lengths and brush sizes, Goodway’s tube cleaning machines have a quick connect option that makes switching between rotary shafts very easy.

The RAM PRO XL® pumps water through the rotary shaft and loose debris gets pushed out as the brush works its way down the length of the tube. Technicians can add TubeGuard®-XL to the RAM-PRO-XL® reservoir to prevent biofilm growth and provide a layer of corrosion protection to copper and other ferrous metal tubes. The corrosion inhibitor in TubeGuard®-XL keeps protecting tubes long after the maintenance is complete and the chiller is put back in operation.

Tube cleaning is a necessary preventative maintenance task for chillers and failure to clean the tubes leads to scaling, corrosion, and reduced heat transfer through the system. As heat transfer efficiency goes down, operating and maintenance costs go up. No matter the size of your chiller plant, from a 130,000-ton behemoth in the heart of the scorching desert to the 100-ton chiller cooling your office building, Goodway’s line of tube cleaners keep chillers running efficiently so you and your customers stay cool.

Next Steps

  • Read more posts on chiller maintenance.
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  • Utilize our in-house experts and allow them the opportunity to assess your specific equipment and determine what cleaning method will offer you the best results.
  • Ask about our customizable capabilities.

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