Two-stage high frequency pulse tube cooler for refrigeration at 25K

Abstract

A two-stage Stirling-type U-shape pulse tube cryocooler driven by a 10 kW-class linear compressor was designed, built and tested. A special feature of the cold head is the absence of a heat exchanger at the cold end of the first stage, since the intended application requires no cooling power at this intermediate temperature.Simulations where done using Sage-software to find optimum operating conditions and cold head geometry. Flow-impedance matching was required to connect the compressor designed for 60 Hz operation to the 40 Hz cold head. A cooling power of 12.9 W at 25 K with an electrical input power of 4.6 kW has been achieved up to now. The lowest temperature reached is 13.7 K.

Development of high performance moving-coil linear compressors for space Stirling-type pulse tube cryocoolers

“…Traditionally, the two-stage or multi-stage SPTCs were often employed to realize the applications below 40 K [93][94][95][96], but the single-stage arrangement significantly reducing the system's complexity and cost were more attractive. In recent years, both singlestage in-line and coaxial STPs working below 40 K have achieved some new progresses in both no-load temperature and cooling ability in the world [53,85,97,98].…”

Theoretical and experimental investigations on Stirling-type pulse tube cryocoolers with U-type configuration to achieve temperature below 20 K

“…Yang and Thummes 5 developed thermal-coupled PTC, which achieves a no-load temperature of 12.8 K, with 200 W input power to each stage, by using leadcoated meshes at the second-stage regenerator. Dietrich and Thummes 6 reported a minimum temperature of 13.7 K with 4.6 kW input power, which is very high and equivalent to the power requirement of Gifford Mc-Mohan PTCs. The G-M type PTC is not so efficient due to the presence of valves.…”

Temperature inhomogeneity in high capacity pulse tube cryocoolers

“…The University of Giessen has reported on such a cryocooler assembly and demonstrated its effectiveness in reducing the temperature inhomogeneity (Dietrich and Thummes, 2010). PV power (kW) SS #400 SS #400 + Brass #353 SS #400 + Cu #80 SS #400 + Cu-plate SS #400 + Brass #353 + Cu-plate…”