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 controlSTATUS: Phase I Only
