Numerical investigation of the effect of fluid nanohybrid type and volume concentration of fluid on heat transfer and pressure drop in spiral double tube heat exchanger equipped with innovative conical turbulator

Abstract

Spiral heat exchangers in the heat transfer field have attracted researchers' attention due to their better heat transfer characteristics. This review discusses the increase in efficiency of this type of converter. to better understand the efficiency of the intended spiral exchanger, thermal efficiency (performance evaluation criteria) was chosen as the performance index in the present work, and the simulations were carried out in a calm regime (200<Re<800) and for two positive and negative flows and using three types of fluids. This study aims to conduct a numerical analysis of the impact of nanohybrid fluid type and fluid volume concentration on heat transfer and pressure drop in a spiral double-double-tube exchanger incorporating a conical turbulator. Computational fluid dynamics was employed in the study. The problem is tackled using ANSYS FLUENT 18 to conduct CFD simulations utilizing the finite volume method. The numerical findings indicate that employing countercurrent flow and a nanohybrid fluid of Water/MoS2–Fe3O4 significantly impacts overall performance, potentially boosting the spiral heat exchanger's efficiency by 8 %. The findings indicated that raising the volume concentration of the nanohybrid fluid Water/MoS2–Fe3O4 from 0.3 % to 0.5 % and 0.7 % leads to a notable enhancement in the thermal efficiency of this converter type. The converter achieves its peak efficiency at Reynolds number 200 when using the nanohybrid fluid Water/MoS2–Fe3O4, resulting in a 4 % and 17 % increase in thermal performance compared to the other two concentrations.

Keywords

• Helical double pipe heat exchanger
• Rotary generator
• Turbulator
• Fluid nanohybrid
• Counterflow