Thermal and energy management prospects of γ-AlOOH hybrid nanofluids for the application of sustainable heat exchanger systems

This study focuses on double-tube heat exchanger (DTHE) to numerically examine their thermal performance by considering two types of hybrid nanofluids: (i) TiO2-gamma-AlOOH/water and (ii) TiO2-gamma-AlOOH/ethylene glycol. gamma-AlOOH is an efficient material for heat transfer application. The heat exchanger consists of two tubes, which are called the inner and the outer tubes. The coolant and the hot oil, respectively, flow into the inner and the outer tubes. The volume proportion and volume fraction of nanoparticles are 90:10 (gamma-AlOOH/TiO2) and from 0.1 to 0.5%, respectively. The rates of mass flow, alongside the heat transfer rate and the pumping power, are evaluated. The employed model to solve the governing equations is a multiphase mixture, validated with earlier reports. The boundary conditions are reliable for industry deployment. When TiO2-gamma-AlOOH/water is employed rather than TiO2-gamma-AlOOH/EG, 50% improvement in heat transfer rate is obtained. It is noted that TiO2-gamma-AlOOH/EG possesses a higher (30%) pumping power than TiO2-gamma-AlOOH/water. However, to estimate the energy consumption in industrial scale, an additional analysis on pumping power of heat exchanger with EG-based coolants are needed in the future.

Automated summary

This study focuses on the thermal performance of double-tube heat exchangers with two types of hybrid nanofluids, showing that TiO2-γ-AlOOH/water leads to a 50% improvement in heat transfer rate compared to TiO2-γ-AlOOH/ethylene glycol. However, the latter has a higher pumping power by 30%. Further analysis on the energy consumption of heat exchangers with ethylene glycol-based coolants on an industrial scale is needed for future research.