Numerical Investigations on the effect of high frequency and regenerator porous matrix on the performance of miniature pulse tube cryocooler

Abstract

quotWith the growing demand for small satellites require a miniature cryocooler for the thermal management of the high performing infrared (IR) sensors in the cryogenic temperatures (lt 150 K). Pulse tube cryocoolers (PTC) are durable and rugged refrigerators than Stirling cryocoolers typically used in space applications. Miniaturization of pulse tube cryocooler has been a subject of intense research due to the absence of moving component at the cold end which results less vibration, high reliability, and longevity. However its design is quite complicated at the reduced scale because of the complex heat transfer process occurs inside the system. The regenerator is one of the key components to operate a Miniature Pulse Tube Cryocooler (MPTC) at high efficiency. MPTC needs to operate at ultra high frequencies which detoriates the performance of the regenerator and thus restricts the miniaturization of the PTC. newlineThe objective of the present investigation is to study the influence of geometrical and operating parameters on the performance of a miniature pulse tube cryocooler and further explore the possibilities of the different matrices as regenerator filler materials for MPTC operating at ultra-high frequencies using the National Institute of Standards and Technology (NIST) software tool REGEN 3.3. REGEN 3.3 Software is widely used for the design and optimization of the regenerator for pulse tube cryocoolers by academic researchers and industries. A numerical study is carried over a broad range of ultra-high frequency (100 - 200 Hz), charge pressure (3.5-7.0 MPa), and pressure ratio (1.15-1.3) for an regenerator of MPTC operating in temperature between 300 K and 80 K at cooing power of 1 W. The effects of different regenerator matrix material viz. stainless steel wire mesh screen, brass wire mesh screen, and copper wire mesh screen on the coefficient of performance (COP) of the MPTC were also studied. Eventually, the complete system-level CFD models were investigated with different matrix materials and operating paramete