Upgrading the performance of shell and helically coiled heat exchangers with new flow path by using TiO2/water and CuO–TiO2/water nanofluids

Abstract

Along with the developing technologies, the need for energy has increased day by day and negative environmental effects of fossil energy based systems increased the importance of efficient energy systems. In the recent years, shell and helically coiled type heat exchangers (SHCHEs) are extensively used in various applications because of their superior specifications in comparison with other heat exchangers. In the present work, it is targeted to raise the thermal performance of recently developed shell and helically coiled heat exchangers using single and hybrid type nanofluids. The main aim of this research is specifying the impact of hybrid CuO–TiO2/water nanofluid in comparison with single TiO2/water nanofluid. Also, the effect of adding fins as turbulators on performance enhancement of nanofluids was analyzed. In this regard, TiO2/water and CuO–TiO2/water nanofluids with 1% (wt./wt.) concentration was prepared and circulated in the hot side of both heat exchangers. TiO2/water working nanofluid application in finless and finned SHCHEs averagely upgraded overall heat transfer coefficient as 7.5% and 8.6%, respectively. CuO–TiO2/water working nanofluid application in finless and finned SHCHEs averagely upgraded overall heat transfer coefficient as 10.8% and 12%, respectively. Generally, it was observed that utilizing TiO2/water and CuO–TiO2/water nanofluid in unmodified and modified SHCHEs importantly raised the thermal performance. However, utilization of hybrid type nanofluid presented better performance than single nanofluid in both SHCHEs. Moreover, the outcomes exhibited further positive impacts of integrating fins on performance enhancement of both single and hybrid nanofluids.