As the power dissipation in high performance personal
computers continues to increase, closed loop liquid cooling
systems offer an excellent means to provide efficient reliable
cooling with high cooling capacity and low noise. The design
of all the key components of a liquid cooling system for PC’s
was described. System integration for long life operation using
low permeation flexible FPE tubing, vacuum leak testing and
coolant filling to a positive system pressure were described.
The wetted components of the cooling system were made
from copper and copper alloys which provide very good
reliability with aqueous coolants in single-phase liquid cooling
systems. Aluminum plate fins were used on the air side of the
heat exchanger for low mass. Corrosion tests were performed
to identify attractive coolant chemistries that provide long term
corrosion protection of the wetted components as well as freeze
protection down to -40 ο
C.
Bench tests were performed with water as the liquid
coolant to measure the performance of the CPU cold plate and
the liquid to air heat exchanger to validate the design methods
for the respective components. The validated design methods
were used to scale the performance to the 50% ethylene glycol
coolant used in the demonstration cooling system for a PC.