Nitrogen heat pipe for cryocooler thermal shunt

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:416633

Prenger, F C; Hill, D D; Daney, D E ^[1]

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1. Los Alamos National Lab., NM (United States); and others

A nitrogen heat pipe was designed, built and tested for the purpose of providing a thermal shunt between the two stages of a Gifford-McMahan (GM) cryocooler during cooldown. The nitrogen heat pipe has an operating temperature range between 63 and 123 K. While the heat pipe is in this temperature range during the system cooldown, it acts as a thermal shunt between the first and second stage of the cryocooler. The heat pipe increases the heat transfer to the first stage of the cryocooler, thereby reducing the cooldown time of the system. When the heat pipe temperature drops below the triple point, the nitrogen working fluid freezes, effectively stopping the heat pipe operation. A small heat leak between cryocooler stages remains because of axial conduction along the heat pipe wall. As long as the heat pipe remains below 63 K, the heat pipe remains inactive. Heat pipe performance limits were measured and the optimum fluid charge was determined.

• OSTI ID: 416633
• Report Number(s): CONF-950722--
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COOLING TIME
CRYOGENICS
HEAT PIPES
HEAT TRANSFER
NITROGEN
VAPOR COMPRESSION REFRIGERATION CYCLE