CuproBraze® 57

ExecutRivepoert New - Heat Exchangers Excel in Generator Set, , Off-Road and Military Applications End Users Favor CuproBraze Technology for Cooling Efficiency and Durability

new wave of interest has materialized Moreover, aluminum has durability issues at for CuproBraze technology, especially the higher and pressures that are for stationary generators, , necessary to meet more-stringent emissions off-road equipment and government requirements around the world. and military systems. For these large In selecting heat exchangers for locomotive, heat exchangers, CuproBraze faces generator sets and off-road applications, Aoff against at least three competitive core consideration should be given to cooling technologies: efficiency and durability, including , • Soldered copper/brass plate fin fatigue and elevated temperatures. • Soldered copper/brass serpentine fin • Brazed aluminum serpentine fin Maximizing Cooling Efficiency Nonetheless, CuproBraze technology is now The main performance criterion for heat the first choice for many of these applications. exchangers is cooling efficiency, which It represents a breakthrough technology that describes the heat dispersion from a given has been anticipated for a long time. space by a heat exchanger. Greater efficiency In this report, key design criteria are means the same heat can be dispersed with a examined for the heat exchangers that are used smaller core, so it amounts to a size advantage. in locomotives, stationary generators and off- Cooling efficiency is especially important road applications. in applications where the diesel are stationary, because the flow of cooling air is not provided by the vehicle velocity. Copper- Competitive Advantages brass cores can disperse more heat per unit volume than any other material system. The chief reason for the popularity of However, efficiency is determined by not CuproBraze technology is that it allows for only the materials but also the design. The the use of brazed serpentine-fins (often of efficiency of typical large heat exchangers is the square-wave type) in brazed copper-brass influenced by the following factors: heat exchanger designs. The latter have the following advantages over competitive designs: • of fin materials • Less expensive to manufacture than soldered • Spacing, size, thickness and shape of fins plate-fin designs • Shape of tubes • More durable than soldered serpentine-fin • Velocity of the air passing through the core designs (because of much stronger joints) • Various other design factors • Greater cooling efficiency and more rugged A significant reduction in frontal area and than brazed aluminum serpentine-fin designs volume is typical for a serpentine-fin design (because thinner materials allow for more air with flat tubes compared to a plate-fin design to pass through) with round tubes. Experience so far shows • Square-wave type fins are not easily clogged that CuproBraze technology with a and can be cleaned with pressurized water, serpentine-fin design delivers the maximum allowing the thermal performance to be cooling efficiency in the smallest volume maintained during operation without compromising durability. The International Copper The Finnish Manufacturing caused specific and recurring Company (Finn Radiator) used Luvata’s problems, which vanished once the system Association, Ltd. (ICA) automotive wind tunnel in Sweden to was replaced with a CuproBraze design. evaluate the cooling efficiency of CuproBraze The superior performance of CuproBraze is the leading organization for the promotion of the use of heat exchanger designs. Its customers have radiators in the harsh operating climates of copper worldwide. The Association’s twenty-nine members certified these first-generation CuproBraze this vital transport system operated by the represent about 80 percent of the world’s refined copper output, and its six associate members are among the world’s largest radiators and charge air coolers for use in a government and military was the subject of copper and copper alloy fabricators. ICA is responsible for wide range of off-road applications, including an earlier report [3]. guiding policy, strategy and funding of international initiatives tractors, terminal tractors, piling rigs and Fully assembled heat exchangers made and promotional activities. With headquarters in New York City, special purpose machinery [1]. from CuproBraze alloys, soldered copper- ICA operates in 28 worldwide locations through a network of Similarly, Young Touchstone, a Wabtec brass and brazed aluminum heat exchangers regional offices and copper development associations. Company (Jackson, Tennessee) has certified were subjected to at least four different radiators for use in locomotives and power corrosion tests [4]: For information about the CuproBraze process or ICA’s generation equipment. It supplies Kohler CuproBraze consulting services, please contact the • Road environment pollutant Power with CuproBraze heat exchangers International Copper Association at: • Salt spray [email protected]. for power generators and supplies its sister For European inquiries contact: [email protected]. company MotivePower, a Wabtec Company • Sea water acetic acid (Boise, Idaho) as well as other OEMs in the • Marine air corrosion rail industry with CuproBraze radiators for locomotives [1]. Siemens AG Transportation Test results confirm that CuproBraze resists References Systems (Erlangen, Germany) is also using corrosion much better than soldered copper- 1. “OEMs Reach for Brazed Copper Brass: CuproBraze radiators for locomotive brass and is very competitive with brazed CuproBraze Technology Flourishes in Diverse Applications” ICA CuproBraze Executive Report, applications [1]. aluminum. Papers on the corrosion resistance Issue 55. of CuproBraze are available from the SAE 2. “Bombardier Achieves Superior Performance at a Lower Initial Cost: Brazed Copper-Brass Cools [4-6] and additional information can be found Locomotive Electrical Equipment,” ICA CuproBraze Executive Report, Issue 51. Quality of Endurance in the “CuproBraze Handbook” [7]. 3. “Celebrated Aircraft Loader System Boasts Brazed A common denominator of locomotive Extensive laboratory testing also quantifies Copper-Brass Radiator: A new design of a copper- brass radiator has been developed for retrofit and and off-road applications is the harsh the superb resistance of CuproBraze heat use on the renowned Tunner aircraft loading sys- exchanger cores to fatigue cracking from tem,” ICA CuproBraze Executive Report, Issue 43. environments in which such heat exchangers 4. Markku S. Ainali, Tapio O. Korpinen, and Olofv must operate. Compared to other materials, room up to 300 ºC [8-11]. Forsén, “External Corrosion Resistance of The ability to withstand elevated tempera- CuproBraze Radiators.” SAE Technical Paper Series brazed copper-brass provides stronger, 2001-01-1718. Available at sae.org. Summary: tougher joints, allowing for more durable tures is another crucial benefit. CuproBraze Based on the results from electrochemical measure- ments and from four different types of accelerated products. – and CuproBraze alone – is qualified for corrosion tests, the external corrosion resistance of the CuproBraze radiators is clearly better than that of Strong brazed joints and the reduction use at high temperatures. Aluminum heat the soldered copper/brass radiators and competitive exchangers simply cannot withstand high with the brazed aluminum radiators, especially as of at the joints makes regards marine atmosphere. CuproBraze heat exchangers extremely temperatures without a total breakdown in 5. Markku Ainali and Leif Tapper, “Interactions their mechanical properties. Aluminum alloys Between the Materials in the Tube-Fin-Joints in rugged. Their excellent resistance to corrosion Brazed Copper-Brass Heat Exchangers,” SAE and fatigue adds up to a long service life in are “temperature challenged” above 200 ºC. Technical Paper Series 2001-01-1726. Available at sae.org. many applications. 6. Tapio Korpinen, “Electrochemical Tests with Bombardier achieved superior performance Copper/Brass Radiator Tube Materials in Coolants,” SAE Technical Paper Series 2001-01-1754. at a lower initial cost using CuproBraze The Second Wave 7. “The CuproBraze Brazing Handbook,” Seventh for transformer oil coolers in electric Copper holds the advantage over Edition, October 2005, Edited by Leif Tapper with co-editors Markku Ainali, Anders Falkenö, and locomotives. Designs based on round aluminum in terms of heat dispersion per Robbie Robinson. Produced and published by Luvata. Available from Luvata or download from copper-alloy tubes with aluminum fins unit volume. www.cuprobraze.com. frequently had to be overhauled due to In terms of durability, CuproBraze 8. “Experiments Demonstrate Durability of Brazed Brass Joints: Fatigue Testing at Various overheating, taking the locomotives out of has proven itself in applications such Temperatures Proves Superiority of Copper-Brass as locomotives, generator sets and off- for Heat Exchanger Applications,” ICA CuproBraze service. The new CuproBraze heat exchangers Executive Report, Issue 46 provide superior performance at a lower road equipment as well as in military 9. Anders Falkenö, “Experimentally Driven Development environments. of New Heat Exchanger Materials,” paper presented cost and are rugged enough for the harsh at 2006 SAE World Congress, Detroit, Michigan, operating environments [2]. Heat exchanger manufacturers are bracing April 3-6, 2006, SAE Technical Paper Series 2006-01-0727. Another success involves the renowned themselves for a second wave of demand 10. “New Designs of Charge Air Coolers Increase Tunner aircraft loading system, which is for CuproBraze products. This new wave of Performance and Durability, Part I: Laboratory Testing Verifies Claims of Durability and Efficiency,” now made by DRS Sustainment Systems (St. popularity is due to superior durability and ICA CuproBraze Executive Report, Issue 41 Louis, Missouri) for the USAF. The soldered cooling efficiency in harsh environments. ■ 11. “New Designs of Charge Air Coolers Increase Performance and Durability, Part II: Laboratory Testing Aids in Design Improvements,” ICA CuproBraze Executive Report, Issue 42. International Copper Association, Ltd. 260 Madison Avenue, 16th Floor, New York, NY 10016-2401 Tel: 212.251.7240, Fax: 212.251.7245