• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.33-35
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• 2003

There are three types that geometrical arrangement of the pulse tube and regenerator - in line type, U type, and coaxial type. The most compact and convenient one practical applications is the coaxial type. It can replace Stirling cryocooler without any change to the Dewar or the connection to the cooled devices. To investigate effects of the inertance tube, we perform experiments with varying inertance tube inner diameter and length. The experimental results show that optimum inertance tube inner diameter and length are 1.3mm, 1900mm respectively.

• Progress in Superconductivity and Cryogenics
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• v.6 no.4
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• pp.46-50
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• 2004

The Experimental results of the in-line type inertance tube pulse tube cryocooler for cooling superconductor RF filter are presented in this paper. The pulse tube refrigerator, which has no moving parts at its cold section, is attractive in obtaining higher reliability, simpler construction, and lower vibration than any other small refrigerators. The purpose of this study is to analyze the characteristics of in-line type inertance tube pulse tube refrigerator (IPTR), and to get main factor to improve the performance of the in-line type IPTR. Firstly, design parameters of the in-line IPTR are discussed by ARCOPTR program, and then to find optimal conditions of in-line type IPTR, cool down characteristics according to the variations of the charging pressure, inertance tube volume, regenerator volume and pulse tube volume are measured by the experiment. The lowest temperature of the cold end was about 50 K. Cooling capacity was the highest in the charging pressure of 32 atm. and 5W at 72K. On the other hand, COP of the in-line type IPTR was the highest in the charging pressure of 21 atm. and 0.018 at 77K.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.197-201
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• 2002

A free piston and free displacer (FPFD) Stirling cryocooler and inertance pulse tube cryocooler for the cooling infrared detector and cryosensor are currently under development at Korea Institute of Machinery ＆ Materials. The pulse tube cryocooler, which has no moving parts at its cold section, is attractive for obtaining higher reliability, simpler construction and lower vibration than in any other small cryocoolers. In recent years, pulse tube cryocoolers have experienced a rapid development with the aim to eventually replace Stirling and Gifford-McMahon cryocoolers in various applications. In this study, operating characteristics of the conventional linear Stirling cryocooler was investigated by experiment. And, inertance pulse tube cryocooler with the commercial linear compressor(Leybold Polar) was designed, manufactured, and tested by the variations of the operating frequency, charging pressure and input power.

• Journal of computational fluids engineering
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• v.19 no.3
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• pp.14-19
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• 2014

The flow characteristics of inertance pulse tube cryocooler(IPTC) was investigated with a computational thermal fluid dynamics for the reciprocating flow in IPTC including the piston movement of linear compressor. Two dimensional axisymmetric modeling was applied for the flow in an IPTC with a clearance between the piston and cylinder wall of linear compressor. The pressure, velocity, and temperature distribution were examined for the steady state. These were compared with previous results to confirm the validity in the modeling and computational results. The leakage between piston and cylinder wall affect the cooling capacity seriously. The dependence on mesh numbers were also examined to obtain a proper mesh numbers to improve the accuracy of calculation, which showed significant effect on the results. The user-defined function was used for the process of compression and expansion of piston.

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.197-197
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• 2004

• Progress in Superconductivity and Cryogenics
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• v.15 no.3
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• pp.35-39
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• 2013

In this paper, we present test results of developed 100 W class linear compressor for Stirling-type pulse tube refrigerator. The fabricated linear compressor has dual-opposed configuration, free piston and moving magnet type linear motor. Power transfer, efficiency and required pressure waveform are predicted with designed and measured specifications. In experiments, room temperature test with flow impedance is conducted to evaluate performance of developed linear compressor. Flow impedance is loaded to compressor with metering valve for flow resistance, inertance tube for flow inertance and buffer volumes for flow compliance. Several operating parameters such as input voltage, current, piston displacement and pressure wave are measured for various operating frequency and fixed input current level. Behaviors of dynamics and performance of linear compressor as varying flow impedance are discussed with measured experimental results. The developed linear compressor shows 124 W of input power, 86 % of motor efficiency and 60 % of compressor efficiency at its resonant operating condition.

• Transactions of the KSME C: Technology and Education
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• v.3 no.4
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• pp.241-248
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• 2015

Most of the Stirling cryocoolers used for infrared detector cooling in domestic is imported. Because the cooler has a high price, short life and poor durability, demand for the coolers continues steadily. However, the cooler is highly related to defense and space technology, technology transfer or co-development with the countries having experties in cooler design is very limited. The pulse tube cooler to be developed in this study is such that the mechanical piston in low temperature actuating part is replaced by the gas piston and linear compressor is adopted, which results in low vibration, long life and better durability. It is expected that development of the pulse tube cooler will not only improve our technology to the level of advanced countries, but also enhance the skills in designing and manufacturing of the infrared detector.