A heat exchanger is a device that is used to transfer thermal energy between two or more fluids, between a solid surface and a fluid, between solid particulates and fluid, at different temperatures. Heat exchangers are important engineering devices in many process industries since the efficiency and economy of the process largely depend on the performance of the exchanger. Aluminium Oxide has a more thermal conductivity and is dispersed in water as Base Fluid. Copper Material has a maximum thermal conductivity and is used as a material of Double Pipe Heat Exchanger. The Concentration of the Nano Fluids size is in Base Fluids Plays a major role as its size increases density increases. Heat Exchangers considered to have great potential for heat transfer enhancement and are highly suited to application in heat transfer processes. In recent years, several important research works have been carried out to understand and explain the causes of the enhancement or control of heat transfer using Nano fluids. Nano Particles are expensive so analysis is useful than the experimental investigation of Nano fluid Properties for better heat exchanger. CFD simulations shall be done for three Al2O3-water Nano fluid concentrations of 0.1%, 0.2%, and 0.3% by volume.