95 K High Efficiency Cryocooler Program

Abstract

The Air Force / Raytheon 95K High Efficiency Cryocooler (95K HEC) Program is developing a new two-stage hybrid Stirling-pulse tube space qualified refrigerator with high heat lift capacity, high efficiency, low weight and size, and low production costs relative to the current state-of-the-art. The basic program will deliver a protoflight Stirling-class Thermo Mechanical Unit (TMU) with protoflight radiation hard electronics. The cooler is designed to support 10W heat lift from a 95K source to a 300K sink. Motor power consumption is to be less than 100W and system power (including electronics) is to be less than 137W. The cooler is to weigh no more than 6Kg. The TMU cold head and compressor designs are highly versatile to enable low cost tailoring to meet the needs of a wide variety of applications. The first demonstration of this versatility is a program option to deliver a companion high-capacity 35K cryocooler. This cooler will also have an aggressive efficiency requirement. The 95K and 35K TMU will share over 95% of components, resulting in significant production efficiencies. Another result of this high degree of commonality is that each cooler can be powered and controlled by standardized Command and Control Electronics (CCE). The only adjustments needed to match the CCE to a TMU design are in selected logic parameters stored in ROM and in minor changes to winding ratios in two transformers. The CCE is designed with radiation hard components, but the initial protoflight units will be delivered with lower cost commercial substitutes, where available with the same form, fit, and function. The 25 month program will deliver a fully flight qualified 95K system including both TMU and CCE and, if the option is exercised, a similar flight qualified 35K system.