Abstract: A heat exchanger is a device that is used to transfer thermal energy (enthalpy) between two or more fluids, between a solid surface and a fluid, or between solid particulates and a fluid, at different temperatures and in thermal contact. The goal of enhancing heat transfer while minimizing pressure drops and reducing the size and volume of energy conversion/thermal management systems has been the subject of intensive research for more than four decades. But growing energy demands, the need for increased energy efficiency and materials savings, space limitations for device packaging, and increased functionality and ease of unit handling have created revolutionary challenges for the development of high performance, next-generation heat and mass exchangers. Current heat exchanger designs rely heavily on fin-and tube or plate heat exchanger designs, often constructed using copper and aluminum. The strive for heat exchangers that are more compact and highly efficient has led to the development of micro-channel heat exchangers. The innovative micro-channel heat and mass exchangers appear to be the most promising way to meet these challenges in thermal management. When properly designed and utilized, micro-channels can distribute the flow precisely among the channels, reduce flow travel length, and establish laminar flow in the channels while achieving high heat transfer coefficients, high surface area-to-volume ratios, and reduced overall pressure drops. These are among the major advantages of micro-channels for use in a diverse range of industries.

Keywords: Heat Exchanger, Nano-fluid.