Heat exchangers are used in many different types of systems for transferring heat between fluids in single phase, binary or two-phase applications. Many different types of heat exchangers are known including plate-fin, plate-frame, and shell-and-tube heat exchangers. In plate-fin heat exchangers, a first fluid or gas is passed on one side of the plate and a second fluid or gas is passed on another side of the plate. The first fluid and/or the second fluid flow along channels between fins mounted on one side of the plate, and heat energy is transferred between the first fluid and second fluid through the fins and the plate. Materials such as titanium, high alloy steel, copper and aluminum are typically used for the plates, frames, and fins. The use of radial-flow heat exchangers in air-air heat exchange applications is known.
Brazed aluminum heat exchangers are mostly used in small, compact and highly efficient heat exchange operations. However, some heat exchange applications utilize a small temperature differential and thus require higher efficiency to make use of heat exchangers in those applications economical.