The experimental setup for studying supercooling behavior
during freezing of CueH2O nanofluids test is shown in Fig. 2. The
thermal response test was performed on a low constant temperature
trough (DC2006, Institute of Xinzhi Scientific Instrument,
Ningbo, China). The glycolewater mixture was poured into the low
constant temperature trough and served as the coolant. The volume
ratio of glycol to water was 1:1. During the test, the temperature of
the glycolewater mixturewas maintained at 20 C for the cooling
period. Four 50 ml cylindrical tubes filled with 35 ml nanofluids
were put into the low constant temperature trough. Their concentrations
are 0.00 wt%, 0.10 wt%, 0.50 wt%, 1.00 wt%, respectively.
The temperature of samples inside the test tubes was measured by
the T-type thermocouple with a diameter of 0.2 mm. The test
precision of this thermocouple is ±0.2 C. To reduce systematic
error, the temperature values of nanofluids and water PCMs in the
solidification process were measured multiple times. The temperature
datalogger (Agilent 34970A) collected the values of temperatures
and the time interval was 30 s.