Heat exchangers used in automotive and truck industry are mainly manufactured according 3 technologies: soldered copper-brass, mechanically assembled aluminum and brazed aluminum. Shares of each technology can vary according to different criteria: cost, weight, corrosion resistance, performance in a limited volume, air pressure drop, temperature resistance, reliability, etc.
Aluminum has been more and more used in the last decade; one of the reasons is the gain of weight in order to reduce fuel consumption. But the necessity of setting new exchangers, such as evaporators or condensers for air conditionning, oil coolers for high performance engines or automatic gear boxes, charge air coolers for turb-charged diesel engines, which require high pressure and temperature resistance, has made brazed aluminum more and more popular.
This paper compares the 3 technologies that are worldwide used to produce brazed aluminum heat exchangers: vacuum, air furnace and controlled atmosphere brazing.