Nanofluid Thermal Conductivity and Performance of its Pulsating Heat Pipe

W. Qu, Z. Xue, J. Yu
China Academy of Aerospace Aerodynamics,
China

Keywords: nanlfluid, thermal conductivity, measurement error, performance of nanofluid pulsating heat pipe

Summary:

Nanofluid is a promising candidate to become the working fluid of pulsating heat pipe, the thermal conductivity should be known before application. Several methods of measuring thermal conductivity of liquid are compared, especially for the single and double transient hot-wire methods. The obtained thermal conductivities by single Φ50μm and Φ20μm wire are close to those by double Φ50μm wire. The suspension characteristics of nanofluids are visualized. The evenly suspending state could be achieved in TiO2/H2O nanofluid by ultrasonic and pH value adjustment, however it is less effective for CuO/H2O nanofluids. Also, the measurement setup is established and the thermal conductivities of four kinds of nanofluids are measured. The results show that the thermal conductivity will increase remarkably with the particle ratio for good suspension nanofluids TiO2/H2O. The measurement error could be less 3%. The performance of nanofluid pulsating heat pipe shows better performance compared with that of the pure liquid without non nano particles added.