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\(P_{W}\) \(=\) \(I^{2}R\).