Thermal performance study of heat exchanger by applying nanofluids

Abstract

The current research proposes a numerical investigation in the triple tubular concentric heat exchanger (TTCHE). Numerical validations of the TTCHE's performance in parallel flow are made. Using the CFD commercial software ANSYS 19.2, temperature variations for the flow of three separate fluids normal-hot–cold (NHC) and cold-hot-normal (CHN) estimates are made through the triple tube's length. When water is supplied, hot fluid always runs through the middle tube, while cold and normal fluid alternately flows along the other tubes. The outside pipe, middle pipe, and inner pipe have respective diameters of 0.1015 m, 0.076 m, and 0.05 m; the tube is 4 m long. The thickness is 1.50 mm of each tube. Then, employing Al2O3 and TiO2 nanofluids in 0.01 %, 0.03 %, 0.05 %, and 0.07 % wt. fractions instead of normal fluid in both scenarios (CHN & NHC), the computed OHTC enhanced upto 19.89 % and 19 % by employing water based Al2O3 and TiO2 nanofluids. The results showed that the HTC increases as the wt. fraction of nanofluids increases. Compared to other arrangements, the NHC has better performance.