Enhancing heat transfer performance in forced convective systems using experimental study with crystalline nano cellulose-dispersed H₂O/C₂H₆O₂ nanofluids

Abstract This work examines the heat transfer properties of a forced convection circular tube heat exchange system employing a nanofluid made of crystalline nano cellulose (CNC) diluted in a 60:40 ratio of distilled water (H 2 O) and ethylene glycol (C 2 H 6 O 2 ). The objective is to measure the generated nano-fluid's thermal characteristics and analyze its potential for usage as a cooling agent in thermal systems, with a focus on encouraging the use of this biodegradable green coolant. A single pipe forced convection system was used for the experimental experiments, which were focused on a temperature range of 30 °C to 100 °C and nanoparticle volume concentrations of 0.1% to 0.9%. The investigation looks at the density, heat conductivity, and viscosity of the nanofluid, among other important thermo-physical characteristics. The findings show that the coolant's density exhibits an inverse relationship with temperature, increasing as nanoparticle dispersion occurs. At a concentration of 0.9% and room temperature, the dynamic viscosity was 0.0096 kg m −1 .sec. A 0.9% concentration of nanoparticle dispersion resulted in a significant increase in thermal conductivity of 27.8%. The effectiveness of the nanofluid is demonstrated by the measurement of pressure drop and convective heat transfer coefficients across the flow channel. The maximum convective heat transfer coefficient of 262.2 W m −2 K −1 was recorded at a discharge rate of 17.5LPM and a concentration of 0.9% of nanoparticles. A temperature of 70 °C was found to yield the best heat transfer coefficient and the least amount of pressure loss when the nanoparticle volume percentage was 0.65%.