Industrial waste heat refers to energy that is generated in industrial processes without being put to practical use. A substantial amount of energy used by company is wasted as heat in the form of exhaust gases, air streams and liquids that leave the boundaries of an industrial facility and enter to the environment. It is not technically and economically feasible to recover all waste heat in the company. In this paper an effort has made about waste heat recovery system design for brewery companies. It is try to identify source of waste heat and design a new plant layout for the purpose of waste heat recovery. Basically this thesis work is to design a waste heat recovery system for preheating of heavy oil in Dashen Brewery factory and to simulate the flow conditions in the heat exchanger with an aim of identifying optimized operating conditions. In Dashen brewery company heat is basically lost at the boiler, process water heater pipe and Wort kettle chimney. The company uses heavy oil for boiler and this oil needs to be heated to have light oil for better ignition. To heat this heavy oil the company still uses steam but this paper propose a system to use exhaust steam at Wort kettle for heating of heavy oil instead of steam. To recover this waste heat from the chimney different system designs are done such as pipeline design, heat exchanger design and other significant parameter determinations. The overall tasks performed in in this paper are simulated by ANSYS software and observing the effects of temperature distribution, heat flux and convective heat transfer coefficients in pipe flow and heat exchanger. The simulation basically shows the important flow conditions which is impossible to show physically. These results are: Pressure contour for tube inlet, Temperature contour for tube inlet, Pressure contour for shell inlet, Temperature contour for shell inlet Temperature distribution on baffles. From the analytical model it is possible to determine the amount of power consumed by the boiler which is 56.947MW from 6220L/h of furnace oil and from exhaust steam 17.5kW is gained which can burn 190L/h of fuel, in terms of birr it is possible to save 456 L/day× 19.5 birr which is 8892 birr per day.