Project Title:

Joule-Thomson Cooler with Non-Clogging, Active Flow Control

09.06-6708
912358
Joule-Thomson Cooler with Non-Clogging, Active Flow Control
APD Cryogenics, Inc.
1833 Vultee Street
Allentown
PA
18103
Ralph C.
Longsworth
215-791-6768
JPL
NAS7-1163
188

09.06-6708
912358

Abstract:

Joule-Thomson Cooler with Non-Clogging, Active, Flow Control
Space-based sorption compressors require high-efficiency, multistage Joule-Thomson
(JT) heat exchangers with adjustable flow control that will not clog if small amounts
of contaminants are present. This project investigates an innovative means of providing
active flow control by using a pneumatically actuated JT valve coupled to an external
control unit that also is connected to a temperature sensor at a key point in the
heat exchanger. The control can regulate the size of the JT orifice to minimize compressor
power input and also to clear blockages from the orifice, if they occur. Phase I
includes heat exchanger design studies and fabrication and testing of a two-stage
unit with N2 contaminated with NO2  to demonstrate the operation of the flow-control
mechanism and its ability to tolerate contaminants in the gas.
JT refrigerators are strong contenders in providing cryogenic cooling to a wide range
of emerging cryogenic-electronic applications. A reliable active-control mechanism
that is tolerant of some contaminants is vital to the success of JT cooler technology.
sorption compressor, JT refrigerator, non-clogging, active JT flow control