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Heat exchangers are devices that transfer heat in order to achieve desired heating or cooling. An important design aspect of heat exchanger technology is the selection of appropriate materials to conduct and transfer heat fast and efficiently. Copper has many desirable properties for thermally efficient and durable heat exchangers. First and foremost, copper is an excellent conductor of heat. This means that copper's high thermal conductivity allows heat to pass through it quickly. Other desirable properties of copper in heat exchangers include its corrosion resistance, biofouling resistance, maximum allowable stress and internal pressure, creep rupture strength, fatigue strength, hardness, thermal expansion, specific heat, antimicrobial properties, tensile strength, yield strength, high melting point, alloyability, ease of fabrication, and ease of joining. The combination of these properties enable copper to be specified for heat exchangers in industrial facilities, HVAC systems, vehicular coolers and radiators, and as heat sinks to cool computers, disk drives, televisions, computer monitors, and other electronic equipment.〔Schoolscience.co.uk; Resources and news for science education; supported by Research Councils UK; http://resources.schoolscience.co.uk/cda/14-16/chemistry/copch0pg4.html〕 Copper is also incorporated into the bottoms of high-quality cookware because the metal conducts heat quickly and distributes it evenly. Non-copper based heat exchangers are also available. Some alternative materials include aluminium, carbon steel, stainless steel, nickel alloys, and titanium. This article focuses on beneficial properties and common applications of copper in heat exchangers. New copper heat exchanger technologies for specific applications are also introduced. ==History== Heat exchangers using copper and its alloys have evolved along with heat transfer technologies over the past several hundred years. Copper condenser tubes were first used in 1769 for steam engines. Initially, the tubes were made of unalloyed copper. By 1870, Muntz metal, a 60% Cu-40% Zn brass alloy, was used for condensers in seawater cooling. Admiralty metal, a 70% Cu-30% Zn yellow brass alloy with 1% tin added to improve corrosion resistance, was introduced in 1890 for seawater service.〔Gaffoglio, Carl J., Copper alloy surface condenser tube application and service considerations; CDA Heat Exchange Seminars; Copper Development Association〕 By the 1920s, a 70% Cu-30% Ni alloy was developed for naval condensers. Soon afterwards, a 2% manganese and 2% iron copper alloy was introduced for better erosion resistance. A 90% Cu-10% Ni alloy first became available in the 1950s, initially for seawater piping. This alloy is now the most widely used copper-nickel alloy in marine heat exchangers. Today, steam, evaporator, and condenser coils are made from copper and copper alloys.〔Steam coils; Super Radiator Coils; Replacement coils brochure: http://www.srcoils.com/wp-content/blogs.dir/1/files/2010/05/Super-Replacement-Coils-2010-web.pdf〕 These heat exchangers are used in air conditioning and refrigeration systems, industrial and central heating and cooling systems, radiators, hot water tanks, and under-floor heating systems. Copper-based heat exchangers can be manufactured with copper tube/aluminium fin, cupro-nickel, or all-copper constructions. Various coatings can be applied to enhance corrosion resistance of the tubes and fins.〔〔10 tips on getting the most from your coil; Super Radiator Coils; http://www.srcoils.com/wp-content/blogs.dir/1/files/2010/05/T003-10-Tips.pdf〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Copper in heat exchangers」の詳細全文を読む スポンサード リンク
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