Hybrid cooling system testing contains a liquid cooling system
and VCRS that started at the same time. For the hybrid systems,
we just waited until the temperature of the heater module reached
a stable state within ±1 C at different heating power, and then
continuously operated the system for 10 min at stable state and
averaged the test data as the experimental data. This experiment
confirmed the dissipation performance and total pumping power
consumption of the hybrid cooling system. Finally, this study tests
the dynamic dissipation performance of the hybrid cooling system
test in switching between two cooling systems or using different
levels of heating power to test dissipation performance. This experiment showed the system’s cooling ability in response to heating
load changes.To assess the heat exchange performance of the heat
exchanger for different cooling systems under the same test conditions, the surface temperature of the heat exchanger base plate and
the heater was measured at the surface geometric center [34,35].
The surface geometric center temperature of the heat exchanger
or heating module can represent the surface mean temperature
of the heat exchanger or heating module due to the copper with
very high thermal conductivity. We measured surface temperature
of the heating module and the heat exchanger to monitor the state
of contact between the heating module and the heat exchanger in
order to check if the installation of the cooling system was correct.
The temperatures on the hybrid cooling system were measured
using a data-acquisition unit (MV-200, YOKOGAWA, Japan) with
six thermocouples (K-type) at different points, and the accuracy
of the temperature measurements was ±0.5 C. To reduce experimental deviation, the environmental temperature and relative
humidity was controlled at 25 ± 1 C and 70 ± 5% by an air-conditioning system during the heat dissipation experiments.