Patent ID: 7363767
Filing Date: 2008-04-29
Classification: F25B,F25D

Abstract:
1. A three stage pulse-tube cryocooler comprising: a first stage regenerator having a hot end thermally coupled to a heat sink and a cold end, the hot end being in fluid communication with an oscillating source of working fluid under pressure; a first stage pulse tube having a hot end thermally coupled to the heat sink and a cold end with a first stage cold end heat exchanger thermally coupled to a first stage cooling station, the cold end of the first stage pulse tube being fluid coupled to the cold end of the first stage regenerator through the first stage cold end heat exchanger; a second stage regenerator coupled for fluid flow in series with the first stage regenerator, having a hot end and a cold end; a second stage pulse tube having a hot end thermally coupled to the heat sink and a cold end thermally coupled to a second stage cooling station; a gas flow expansion passage providing a fluid coupling between the cold end of the second stage regenerator and the cold end of the second stage pulse tube; a third stage regenerator coupled for fluid flow in series with the second stage regenerator, having a hot end and a cold end; and a third stage pulse tube coupled for fluid flow in series with the second stage pulse tube, having a hot end thermally coupled to the second stage cooling station and a cold end having a third stage cold end heat exchanger thermally coupled to a third stage cooling station, the cold end of the third stage pulse tube being fluid coupled to the cold end of the third stage regenerator through the third stage cold end heat exchanger.