Experimental investigation of thermal efficiency in shell and helically coiled tube heat exchangers with 𝐅𝐞𝟑𝐎𝟒 magnetite nanoparticles

In this study, the effect of Fe3O4 magnetite nanoparticles on thermal performance of a shell and helically coiled tube heat exchanger was investigated experimentally. The nanoparticles with a diameter of 26 nm dispersed in a base fluid with the particle volume concentrations of 0.03%, 0.06% and 0.1%. Ethylene glycol and water mixture used as the base fluid. The experiments have been conducted at different concentrations of water and ethylene glycol, different particle volume concentration and different coil side flow rate. Fluid on shell side is water and fluids on coil side are water, ethylene glycol/water mixture and nanofluid. Results show that Nanofluids improve the thermal performance of heat exchangers. For example, convective heat transfer coefficient increases about 65% for ethylene glycol/distilled water mixture based on 0.1% Fe3O4 nanoparticle. With a four-fold increase in the flow rate, the tube side Nusselt number increases about 160%. It is concluded that Fe3O4 magnetite nanofluid can be applied as an effective coolant in the helically coiled tube heat exchangers.