Document Type : Original Article
Nuclear Science and Technology Research Institute, Tehran, Iran
In this study, some parameters such as quenching and boiling curves of a stainless steel cylindrical rod 80 mm long and having a diameter of 15 mm were experimentally obtained in saturate pure water and two nanofluids (SiO2 and TiO2) with 0.01 wt%. The cylinder was vertically lowered into the pool of saturated water and its temporal center temperature was measured by a thermocouple. The boiling curves were then obtained by solving a transient one-dimensional inverse heat conduction model and measuring the temperature at the center of the cylinder. The images of the surface morphology and uniformity of the deposited SiO2 and TiO2 nano particles were captured by the scanning electron microscope (SEM). The cooling time during quenching of the cylinder was decreased about 50% by nanoparticles deposition. However, the SiO2 and TiO2 nano particle deposition have similar critical heat flux increment (up to 120%). Film boiling heat transfer rate increased by repetitive quenching in SiO2 nanofluid.