Figure 10. Results from
reboiler outlet flow tests. Circles represent experimental measurements,
with solid horizontal error bars indicating one standard deviation in
either direction. The lines indicate values from the ideal stage model
at three different condenser duties.
Comparing the experimental measurements to the base model predictions
(condenser duty ‑16 W), noticeable deviation is evident at bottoms
liquid flow rates above about 0.20 SLM. One source of this discrepancy
could be the that the cryocooler was not actually providing the full
advertised duty provided by the manufacturer. Accordingly, a separate
experiment was performed to measure the cryocooler duty.
A 5 Ω resistor was mounted to the cryocooler and 9 different voltages
between 6 and 10 V were applied through the resistor. At each voltage
the cryocooler temperature was measured via a thermocouple, and once the
temperature stabilized, the current was measured. The results are shown
in Figure 11, with power (PW ) calculated from the
current \(\left(I\right)\) and resistance \(\left(R\right)\) via\(P_{W}\) \(=\) \(I^{2}R\).