Analysis of Heat Transfer in Semifluid Tube Heat Exchanger Equipped with Spiral Coiled Insert Using Cuo-H₂o Based Nanofluids

Rajni Bunker, Ravi Vishwakarma

Heat exchanger using nano fluid is a device in which the heat transfer takes place by using nano fluid. In this the working fluid is nano fluid. Nano fluid is made by the suspending nano particles in the fluid like water, ethylene glycol and oil, hydrocarbons, fluorocarbons etc. An analysis of forced convection heat transfer has been carried out in a semifluid tube heat exchanger equipped with spiral coiled inserts using CuO/water as a nano fluid and distills water as base fluid. Tests has been conducted for plain tube and for tube with inserts for the determination of heat transfer, friction factor and thermal performance factor in the Reynolds number range 4000 to 10000 and volume concentration from 0.01%, 0.015% and 0.02% of nano fluid at room temperature. The results achieved from the use of the CuO/water nano fluid and helical coiled inserts, are compared with plain tube with and without inserts. The experimental results reveal that at similar operating conditions, heat transfer, friction factor as well as thermal performance factor associated with the simultaneous application of CuO/water nano fluid and spiral coiled insert are higher than those associated with the individual techniques. Evidently, heat transfer rate increases with increasing CuO/water nano fluid volume concentration and decreasing pitch ratio. In addition, the copper oxide based nano fluid coupled with helical coiled insert in a copper tube in parallel arrangement offer higher heat transfer performances than plain tube. In this experimental study, the maximum thermal performance factor 1.23 is found with the use of CuO/water nano fluid at volume concentration of 0.02% in copper tube coupled with helical coiled inserts at pitch ratio (p/d=2) in parallel arrangement, for Reynolds number of 4713.93.