| US 7,412,835 B2 | ||
| Apparatus and method for controlling a cryocooler by adjusting cooler gas flow oscillating frequency | ||
| Edwin L. Legall, W154N6245 Marvel Dr., Menomonee Falls, Wis. 53051 (US); Longzhi Jiang, 2814 Constitution Dr., Florence, S.C. 29501 (US); Roy A. Mangano, 2807 Alberti Dr., Florence, S.C. 29501 (US); and Mark Derakhshan, 18715 Surrey La., Brookfield, Wis. 53045 (US) | ||
| Filed on Jun. 27, 2005, as Appl. No. 11/167,850. | ||
| Prior Publication US 2006/0288710 A1, Dec. 28, 2006 | ||
| Int. Cl. F25D 9/00 (2006.01); F25B 1/00 (2006.01); F25B 49/00 (2006.01) | ||
| U.S. Cl. 62—6 [62/228.1] | 23 Claims |
| 1. An apparatus for adjusting stroke frequency of a cryocooler as a function of pressure in a cryogen pressure vessel, the
apparatus comprising:
a generator for setting an initial stroke rate for the cryocooler by setting alternating or direct current motor speed;
a difference measuring device for continuously measuring in each cycle of operation a pressure difference between a measured
pressure and a set pressure;
a controller for calculating in each cycle of operation a required stroke rate or a frequency adjustment for the cryocooler
from the measured pressure difference;
a variable speed module for combining in each cycle of operation the stroke rate adjustment with the initial stroke rate to
adjust the stroke rate or frequency by adjusting the alternating or direct current motor speed in order to optimize operations
of the cryocooler; and
a thermal gasket operably coupled between the cryocooler and a recondenser to provide a thermal interface, and pressure controller
to selectively adjust a mechanical pressure across the thermal interface, a the pressure controller including a display to
indicate a temperature drop across the thermal interface;
wherein the variable speed module increases the cryocooler stroke rate by increasing the alternating or direct current motor
speed when the measured pressure is greater than the set pressure.
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