共查询到20条相似文献,搜索用时 15 毫秒
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Cooling system for the soft X-ray spectrometer onboard Astro-H 总被引:1,自引:0,他引:1
Ryuichi Fujimoto Kazuhisa Mitsuda Yoh Takei Hiroyuki Sugita Keisuke Shinozaki Yoshitaka Ishisaki Masahide Murakami Hiroshi Murakami Madoka Kawaharada Kosuke Sato Seiji Yoshida Peter Shirron Richard L. Kelley Caroline A. Kilbourne Andrea Mattern Dan McCammon 《低温学》2010,50(9):488-493
The Soft X-ray Spectrometer (SXS) is a cryogenic high resolution X-ray spectrometer onboard the X-ray astronomy satellite Astro-H which will be launched in 2014. The detector array is cooled down to 50 mK using an adiabatic demagnetization refrigerator (ADR). The cooling chain from the room temperature to the ADR heat-sink is composed of superfluid liquid He, a Joule-Thomson cryocooler, and double-stage Stirling cryocoolers. It is designed to keep 30 l of liquid He for more than 5 years in the normal case, and longer than 3 years even if one of the cryocoolers fails. Cryogen-free operation is also possible in the normal case. It is fully redundant from the room temperature to the ADR heat-sink. 相似文献
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Analyzing cryocooler reliability has been problematic from the beginning. Classic reliability analyses rely on statistical sampling and comparing failure modes to other similar systems where statistical results are available. These approaches do not apply to cryocoolers, particularly cryocoolers for aerospace applications. The industry has not built enough total cryocoolers, let alone a single type of cooler, to provide any meaningful statistical sample. This forces us to rely on comparing failure modes of similar systems to that of the cryocooler, which leads to the next problem; today's aerospace cryocooler is designed to have no failure modes. What can it be compared to? Any classic reliability study performed on a cryocooler makes several critical assumptions that completely dominate the results. Change the assumptions and you get a different answer; the results are dictated by the assumptions not the hardware. There are no easy answers to these problems. This paper attempts to show why classic reliability studies do not apply to cryocoolers and that as an industry we must work together to show that all cryocoolers have high levels of reliability. 相似文献
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《低温学》2017
Over the last several years, Raytheon has made significant advances on two long-life cryocoolers designed for efficient operation on space platforms. The first is the Low-Temperature Raytheon Stirling/Pulse Tube 2-stage (LT-RSP2) hybrid cryocooler, which is capable of providing simultaneous cooling at 55 K and 10 K nominal first and second stage temperatures. The LT-RSP2 design was finalized in mid-2009, with fabrication of the prototype unit taking place in late 2009 and early 2010 and execution of the production program in 2011–2015. During this period the LT-RSP2 has undergone extensive characterization testing and has successfully been integrated with an optical bench. The second cryocooler is the Raytheon Advanced Miniature (RAM) cryocooler, a flight packaged single stage pulse tube cooler with an integrated surge volume and inertance tube. It has been designed for high frequency operation and has been fully optimized to make use of the Raytheon Advanced Regenerator, resulting in improved efficiency relative to previous Raytheon pulse tube coolers. In this paper, aspects of both the LT-RSP2 and RAM mechanical and thermodynamic designs will be presented as well as information regarding their capabilities and performance. 相似文献
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《低温学》2006,46(2-3):164-168
Lockheed Martin’s Advanced Technology Center (LM-ATC) in Palo Alto, California, has been active in space cryogenic developments for over 30 years. In prior years, work focused on stored cryogen systems for temperatures up to 125 K. As the mechanical cryocoolers matured and demonstrated reliable operation these stored cryogen systems gradually became replaced. LM-ATC is currently developing solid hydrogen systems for temperatures below 7 K [Naes L, Wu S, Cannon J. WISE solid hydrogen cryostat design overview. In: Proceedings of SPIE, cryogenic optical systems and instruments XI, vol. 5904, August, 2005], but these coolers will soon be replaced by mechanical cryocoolers.This paper will present a summary of cryocooler developments at LM-ATC and will describe the recent performance of multiple stage systems. A four-stage pulse tube cryocooler developed under contract to the Jet Propulsion Laboratory (JPL) has been recently developed and operated at 3.8 K [Olson JR, Moore M, Champagne P, Roth E, Evtimov B, Jensen J, et al. Development of a space-type-4-stage pulse tube cryocooler for very low temperatures, Adv Cryogen Engr, vol. 50, Amer Inst of Physics, New York, in press]. Coolers with one, two and three stages have also been widely developed [3], [4], [5], [6]. A staging approach is required to achieve very low temperatures, and also provides cooling at warmer temperatures, which is invariably beneficial in reducing heat loads to the lower temperature stages, or for cooling other system components. For example, our two-stage cooler [5], [6] is used to cool a low-temperature focal plane as well as a higher temperature optical sensor, using a single compressor and electronics at a substantial benefit in weight, reliability and cost. 相似文献
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《低温学》2006,46(2-3):196-200
Future space missions will include detectors and other components cooled to cryogenic temperatures by adiabatic demagnetization refrigerators (ADRs) coupled with mechanical cryocoolers. In such systems the ADRs require lightweight, low-current superconducting magnets. At least one of an ADR’s magnets must operate at the cryocooler’s coldest stage temperature. This temperature should be as high as possible in order to improve operating efficiency and design flexibility. Until now all space-flight compatible magnets have been made with NbTi wire, which has limited their operating temperatures to below about 5 K. We have developed a lightweight (1 Kg) low-current (8 A) Nb3Sn magnet which produces a 3 T central field at 10 K. We explain the choice of this magnet’s specifications and describe its performance testing. 相似文献
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《低温学》2016
A 3-stage adiabatic demagnetization refrigerator (ADR) (Shirron et al., 2012) is used on the Soft X-ray Spectrometer instrument (Mitsuda et al., 2010) on Astro-H (Takahashi et al., 2010) [3] to cool a 6 × 6 array of X-ray microcalorimeters to 50 mK. The ADR is supported by a cryogenic system (Fujimoto et al., 2010) consisting of a superfluid helium tank, a 4.5 K Joule–Thomson (JT) cryocooler, and additional 2-stage Stirling cryocoolers that pre-cool the JT cooler and cool radiation shields within the cryostat. The ADR is configured so that it can use either the liquid helium or the JT cryocooler as its heat sink, giving the instrument an unusual degree of tolerance for component failures or degradation in the cryogenic system. The flight detector assembly, ADR and dewar were integrated into the flight dewar in early 2014, and have since been extensively characterized and calibrated. This paper summarizes the operation and performance of the ADR in all of its operating modes. 相似文献
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Northrop Grumman Aerospace Systems cryocooler overview 总被引:1,自引:0,他引:1
Mechanical long life cryocoolers are an enabling technology used to cool a wide variety of detectors in space applications. These coolers provide cooling over a range of temperatures from 2 K to 200 K, cooling powers from tens of mW to tens of watts. Typical applications are missile warning, Earth and climate sciences, astronomy and cryogenic propellant management. Northrop Grumman Aerospace Systems (NGAS) has delivered many of the US flight cooler systems and has 12 long life pulse tube and Stirling coolers on orbit with two having over 11 years of continuous operation. This paper will provide an overview of the NGAS cryocooler capabilities. 相似文献
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《低温学》2018
NASA’s interest in human exploration of Mars has driven it to invest in 20 K cryocooler technology to achieve zero boil-off of liquid hydrogen and 90 K cryocooler technology to achieve zero boil-off liquid oxygen or liquid methane as well as to liquefy oxygen or methane that is produced on the surface of Mars. These investments have demonstrated efficiency progress, mass reductions, and integration insights. A history of the application of cryocooler technology to zero boil-off propellant storage is presented. A trade space on distributed cooling is shown, along with the progress of reverse turbo-Brayton cycle cryocoolers, where the specific power and specific mass have dropped, decreasing the mass and power of these cryocoolers. Additionally, the cryocooler technology advancements of recuperators and compressors are described. Finally, NASA’s development ideas with respect to zero boil-off technology are discussed. 相似文献
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Qiuliang Wang Yinming Dai Baozhi Zhao Souseng Song Shunzhong Chen Luguang Yan 《低温学》2009,49(6):305-312
Many areas of research have benefited from the application of conduction-cooled superconducting magnet technology. The middle and small-scale magnets immersed in the liquid helium will be replaced by the easy-operating conduction-cooled superconducting magnet due to convenient operation, lower operating cost and easy for user. For the goal of superconducting magnet applications in the advanced testing for high temperature superconducting (HTS) wire and sample coils, a wide bore conduction-cooled superconducting magnet with available warm bore of ?186 mm and center field of 5-6 T for background magnetic field applications was designed, fabricated and tested. The system allows measurements to be performed in a repeatable and reliable fashion. In order to support the high stress in magnet, the detailed finite element (FE) analysis with electro-plastic model is proposed. The sample cryostat is designed with cryofree. It includes two GM cryocoolers. The detailed design, fabrication and thermal analysis are presented in the paper. 相似文献
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The vibrations of Gifford-McMahon (GM) and pulse-tube (PT) cryocoolers were measured and analyzed. The vibrations of the cold-stage and cold-head were measured separately to investigate their vibration mechanisms. The measurements were performed while maintaining the thermal conditions of the cryocoolers at a steady state. We found that the vibration of the cold-head for the 4 K PT cryocooler was two orders of magnitude smaller than that of the 4 K GM cryocooler. On the other hand, the vibration of the cold-stages for both cryocoolers was of the same order of magnitude. From a spectral analysis of the vibrations and a simulation, we concluded that the vibration of the cold-stage is caused by an elastic deformation of the pulse tubes (or cylinders) due to the pressure oscillation of the working gas. 相似文献
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研制了中国首台高温超导磁储能直接冷却系统,该系统不使用低温液体(液氦、液氮).在10-3Pa的真空度下,高温超导磁体线圈由1台单级GM制冷机从室温293 K冷却到19 K,Bi2223电流引线由另一台制冷机冷却到77 K以下.整个系统在通140 A直流电流的时候产生了4.5 T的磁场.系统连续运行480 h(20 d),磁体和低温系统各参数动态特性良好.实验研究表明,控制系统的漏热,优化磁体内部导冷结构,有效减少热传导部件的接触界面热阻是制冷机直接冷却高温超导磁体的关键技术. 相似文献
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Based on the most recent HTS cable projects worldwide, we discuss the possibility of making long liquid nitrogen cooled HTS lines. We use the concept of inline cryocoolers to achieve cables of infinite length. We model the cable temperature and pressure distribution and determine the cooling power needed per cryocooler as a function of the desired cable unit length. Repetition of this cable unit, including cryocooler and pumps, makes it possible to achieve cables of infinite length and opens the route to complex HTS power grids. 相似文献
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A cool-down time is one of the major factors in many cryocooler applications, especially for the design of conduction-cooled superconducting devices. Cool-down time means a time cooling a thermal mass from a room-temperature to cryogenic-temperature within a stipulated amount of time. The estimation of cool-down time seeks the elapsed time to cool the thermal object by a cryocooler during initial cool-down process. This procedure includes the dimension and properties of thermal object, heat transfer analysis for cryogenic load, thermal interface between cold mass and cryocooler, and available refrigeration capacity of cryocooler. The proposed method is applied to the specific cooling system for 3 T superconducting magnet cooled by a two-stage GM cryocooler. The result is compared with that of experiment, showing that proposed method has a good agreement with experiment. In addition, the initial cool-down time can be shortened by employing thermal link between the cold mass and first-stage of cryocooler. Through a rigorous modeling and analysis taking into account the effect of thermal link size, it is concluded that there exists an optimal cool-down time during initial cooling in conduction-cooled superconducting magnet system. 相似文献
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《低温学》2017
Mechanical cryocoolers for space applications are required to have high reliability to achieve long-term operation in orbit. ASTRO-H (Hitomi), the 6th Japanese X-ray astronomy mission, has a major scientific instrument onboard—the Soft X-ray Spectrometer (SXS) with several 20K-class two-stage Stirling (2ST) coolers and a 4K-class Joule Thomson (JT) cooler, which must operate for 3 years to ensure the lifetime of liquid helium as a cryogen for cooling of its detectors [1], [2]. Other astronomical missions such as SPICA [3], [4], LiteBIRD [5], and Athena [6] also have top requirements for these mechanical cryocoolers, including a 1K-class JT cooler to be operated for more than 3–5 years with no cryogen system.The reliability and lifetime of mechanical cryocoolers are generally understood to depend on (1) mechanical wear of the piston seal and valve seal, and (2) He working gas contaminated by impurity outgases, mainly H2O and CO2 released from the materials in the components of the cryocoolers. The second factor could be critical relative to causing blockage in the JT heat exchanger plumbing and the JT orifice or resulting in blockage in the Stirling regenerator and thereby degrading its performance. Thus, reducing the potential for outgassing in the cryocooler design and fabrication process, and predicting the total amount of outgases in the cryocooler are very important to ensure cryocooler lifetime and cooling performance in orbit.This paper investigates the outgas analysis of the 2ST and the 1K/4K-JT coolers for achieving a long lifetime. First, gas analysis was conducted for the materials and components of the mechanical cryocoolers, focusing on non-metallic materials as impurity gas sources. Then gas analysis of the mechanical wear effect of the piston seal materials and linear ball bearings was investigated. Finally, outgassing from a fully assembled cryocooler was measured to evaluate whether the outgas reduction process works properly to meet the requirement levels. 相似文献
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低温地面支持设备系统CGSE是用于冷却第二代阿尔法磁谱AMS02的磁体组件并将超流氦注入AMS02磁体杜瓦的低温设备系统。介绍用于CGSE系统中气氦管路阀箱和液氦管路阀箱,介绍了阀箱的技术要求、方案设计、结构特征,并进行了强度校核计算,两个阀箱的筒体和下封头的壁厚为4mm,上封头的壁厚为5mm,能满足两个阀箱承受0.1MPa外压的强度要求。 相似文献