Experimental investigation of graphite nanolubricant used in a domestic refrigerator

In this article, the performance of a domestic refrigerator employing isobutane and graphite nanolubricants as working fluids is investigated experimentally. The character of graphite nanoparticles and the nanolubricant was observed through scanning electron microscope, Fourier-transform infrared spectrometer, and dynamic light scattering. It is confirmed that the surface-modified graphite nanoparticles steadily suspend in the form of clusters for a long period of time. The application of the graphite nanolubricants with mass fractions of 0%, 0.05%, 0.1%, 0.2%, and 0.5% to domestic refrigerator was examined by a refrigerator test system according to the National Standard of China (GB/T 8059.1-4). The results showed that graphite nanolubricants work normally and safely in the refrigerator. There were certain reductions on pull-down time, discharge pressure, discharge temperature, suction pressure, and shell compressor temperature. In addition, power consumption of the refrigerator decreased 4.55% using graphite nanolubricant with a mass fraction of 0.1%, while the on-time rate also decreased as well as the pressure rate. Each test lasts for 15 days; the energy saving effect is stable.