Heat transfer coefficient and thermal performance of heat pipe with R134a/mineral oil nanodiamond+Fe 3 O 4 hybrid nanorefrigerant

Abstract

Experimental research has been done on the heat transfer coefficient and thermal performance of heat pipe operating with R134a/mineral oil (5:1% weight percent) based nanodiamond+Fe₃O₄ hybrid nanorefrigerants. The in-situ growth approach was used to create the hybrid nanoparticles, which were subsequently characterized by X-ray diffraction. Using a vibrating sample magnetometer, the prepared sample magnetic measurement was determined. The studies were conducted with varying heat inputs of 100, 150, and 200 W and with particle loadings of 0.1%, 0.5%, and 1.0%, respectively. The results show that when using hybrid nanofluids instead of base fluid, the wall temperatures at the evaporator and condenser sections of heat pipe are lower. At a heat supply of 200 W, the average temperature in evaporator and condenser sections are reduced by 30.08% and 19.21%, respectively. At $\varphi$  = 1.0% vol. loading and 200 W, the thermal resistances in the evaporator and condenser sections drop to 24.58% and 21.74%, respectively. In comparison to the base fluid, the heat transfer coefficients of the evaporator and condenser are greater to 37.08% and 30.24%, respectively, at a heat input of 200 W. The thermal performance of the heat pipe is enhanced by employing the hybrid nanoparticles based nanorefrigerant, and it is also increased with increasing particle loadings.