制冷机与红外探测器耦合技术中的热分析

在空间红外遥感中,红外探测器通过制冷机获取冷量。由于空间应用对制冷机的输入功率有严格的限制,降低导热、辐射冷损、提高传输效率就成为该耦合系统的一个关键问题。应用有限元工程分析软件做了详细的热力学分析,同时通过对耦合系统各构件的有限元热分析,进一步对其结构进行优化。     

制冷机在空间红外遥感领域的应用研究

空间红外遥感探测器主要采用机械制冷机冷却到工作温度,以获得最佳探测效果。通过对国内外红外遥感探测器用制冷机的研究,分析了机械制冷机的发展方向,即大冷量和深低温的制冷机;讨论了制冷机的两个主要性能评价方法,寿命评价和微振动评价;总结了制冷机电磁兼容性、制冷机探测器耦合设计方面取得的经验和需要开展的工作。     

空间机械制冷机的工程化研究现状

空间制冷技术是制约空间红外遥感技术发展的关键技术之一。随着红外遥感元件所需冷量的大幅提高，空间机械制冷机逐渐成为空间制冷的主力军。首先简单介绍国内外空间机械制冷机的工程化进展状况；并结合美国JPL实验室近十年关于机械制冷机的研究报告，概述在空间机械制冷机研制过程中需要重视和考虑的技术问题，有助于加快我国空间机械制冷技术的应用进程。     

大面阵探测器与斯特林制冷机热耦合结构仿真设计与实验

随着空间红外探测器向大面阵和长线阵列方向发展,探测器的低温平台难以被制冷机直接冷却,传统的单点热耦合方式也无法满足低温阵列的温度均匀性要求.提出一种新型的大面阵探测器与斯特林制冷机之间的桥板式热耦合结构,利用Workbench软件对耦合结构的温度分布进行了仿真分析,并进行实验验证.结果表明:冷平台的温度均匀性达到0.2...     

活性炭——氮吸附式低温制冷机

一种采用吸附式压缩机的低温制冷机几乎没有磨损和振动。当发展完善时，这种制冷机不需要电能，它可长时间自动操作，用于冷却灵敏度高的红外探测器，使用寿命估计在十年以上。在实验室实验时，该制冷机在118K产生0．5瓦冷量，其温度可低达100K。     

航天应用的制冷机系统

介绍冷却４×２２ 元 Ｈｇ Ｃｄ Ｔｅ 红外探测器的集成组件的斯特林制冷系统。这是一种单级的牛津型的斯特林制冷机。其特点是采用膜片弹簧支撑、音圈电机驱动、差动变压器的位移传感器和间隙动密封技术。制冷机的最低制冷温度４３ Ｋ, 降温时间２０ ｍ ｉｎ, 其压缩机功耗约３０ Ｗ。制冷机系统采用双机屏蔽轴向对置排列, 以减小系统机械振动和对探测器的电磁干扰。制冷机通过柔性冷链（汇流排）冷却红外探测器组件。系统在８０ Ｋ 时对探测器提供的冷量大于３０ ｍ Ｗ,制冷机功耗４５ Ｗ。冷链温差为２５ Ｋ, 探测器等效温度灵敏度０２ Ｋ。     

空间用3 W@80 K脉冲管制冷机实验研究

为冷却某空间用红外探测器,研制了一台斯特林型脉冲管制冷机。该制冷机为单级同轴型结构,整机重量4.5 kg,设计寿命5年。系统介绍了脉冲管制冷机系统结构及实验装置,测试了制冷机性能及其与杜瓦耦合后的降温特性曲线,实验结果表明,脉冲管制冷机在80 K可提供0—3 W制冷量,比卡诺效率11%,其制冷量可充分满足杜瓦组件的低温和长寿命的工程需求。     

大面阵红外探测器冷平台仿真设计与试验

随着线列红外探测器面阵规模越来越大,传统的制冷机与红外探测器单点连接的耦合方式已经无法满足红外探测器芯片温度均匀性的要求.本文对某型号大面阵红外探测器冷平台及其辅助支撑、柔性冷链进行了相关的结构设计、仿真分析与试验验证,设计的冷平台在正弦和随机振动时变形量小,温度均匀性不大于0.919 K,可以满足大面阵红外探测器的工...     

红外探测器与小型制冷机

小型致冷机可以用来冷却红外探测系统的敏感元件。工作范围为60K到80K。制冷量为0.1瓦到2瓦。这两个指标又取决于冷却的探测器数目和探测器一制冷机接合面的热效率。这类小型制冷机的平均无故障时间应当大于2500小时,而且温度回升要很小。根据菲利浦公司几十年来从事低温工作的经验,在空间红外探测器上,采用斯特林循环的小型制冷机可以     

航天器制冷机的发展概况

随着空间技术的发展，使得各种遥感仪广泛用于航天器上。如红外探测器、Ｘ射线、γ射线和亚毫米波探测器等须在低温下工作才能提高灵敏度，降低热噪声。因此，制冷系统是空间技术不可缺少的重要组成部分。目前采用的制冷系统有：被动制冷包括辐射制冷和低温制冷剂贮存系统；机械制冷机。主要介绍了空间制冷机分类、特点，在航天器上已经和即将使用的制冷机。     

A High Efficiency Coaxial Pulse Tube Cryocooler for Cooling Medium-Wave Infrared Detectors

Journal of Low Temperature Physics - In order to meet the cooling demand of a medium-wave infrared detector, a coaxial pulse tube cryocooler (PTC) working at temperature around 90 K has...     

Performance optimization of a miniature Joule–Thomson cryocooler using numerical model

The performance of a miniature Joule–Thomson cryocooler depends on the effectiveness of the heat exchanger. The heat exchanger used in such cryocooler is Hampson-type recuperative heat exchanger. The design of the efficient heat exchanger is crucial for the optimum performance of the cryocooler.In the present work, the heat exchanger is numerically simulated for the steady state conditions and the results are validated against the experimental data available from the literature. The area correction factor is identified for the calculation of effective heat transfer area which takes into account the effect of helical geometry. In order to get an optimum performance of the cryocoolers, operating parameters like mass flow rate, pressure and design parameters like heat exchanger length, helical diameter of coil, fin dimensions, fin density have to be identified. The present work systematically addresses this aspect of design for miniature J–T cryocooler.     

Development of a 30–50 K dual-stage pulse tube space cooler

There has been a trend towards increasing heat loads for cryogenically cooled Earth Observation instruments in recent years.This is the case at both the current operational temperature levels (∼50K), as well as at lower operational temperature levels (30–50 K). One solution to meet this trend is to use existing pulse tube technology in a double stage configuration. With such technology increased cooling power at a lower temperature can be achieved at the payload detector. Another advantage of such a system is the possibility to increase overall system efficiency by cooling an intermediate shield to avoid parasitic heat losses towards the detector.Therefore a consortium consisting of Thales Cryogenics B.V. (TCBV), Alternative Energies and Atomic Energy Commission (CEA) and Absolut System (AS) is working on the development of a space cryostat actively cooled by a 2-stage high reliability pulse tube cryocooler. This work is being performed in the frame of an European Space Agency (ESA) Technical Research Program (TRP) (refer 4000109933/14/NL/RA) with a target TRL of 6.This paper presents the design of the overall equipped cryostat and cryostat itself but is mainly focused on the 2-stage cryocooler. Design, manufacturing and test aspects of cryocooler and its the lower level components such as the compressor and cold finger are discussed in detail in this paper. The cryocooler test campaign is meanwhile in final stages of completion and the obtained test results are in line with program objectives.     

Design of Near Infrared and Visible Kinetic Inductance Detectors Using MIM Capacitors

Temperature is an extremely important parameter for the material of the space-borne infrared detector. To cool an HgCdTe-infrared detector, a Stirling-type pulse-tube cryocooler (PTC) has been developed based on a great deal of numerical simulations, which are performed to investigate the thermodynamic behaviors of the PTC. The effects of different low temperatures are presented to analyze different energy flows, losses, phase shifts, and impedance matching of the PTC at a temperature range of 40–120 K, where woven wire screens are used. Finally, a high-efficiency coaxial PTC has been designed, built, and tested, operating around 60 K after a number of theoretical and experimental studies. The PTC can offer a no-load refrigeration temperature of 40 K with an input electric power of 150 W, and a cooling power of 4 W at 60 K is obtained with Carnot efficiency of 12%. In addition, a comparative study of simulation and experiment has been carried out, and some studies on reject temperatures have been presented for a thorough understanding of the PTC system.     

A high efficiency coaxial pulse tube cryocooler operating at 60 K

In recent years, improved efficiency of pulse tube cryocoolers has been required by some space infrared detectors and special military applications. Based on this, a high efficiency single-stage coaxial pulse tube cryocooler which operates at 60 K is introduced in this paper. The cryocooler is numerically designed using SAGE, and details of the analysis are presented. The performance of the cryocooler at different input powers ranging from 100 W to 200 W is experimentally tested. Experimental results show that this cryocooler typically provides a cooling power of 7.7 W at 60 K with an input power of 200 W, and achieves a relative Carnot efficiency of around 15%. When the cooling power is around 6 W, the cryocooler achieves the best relative Carnot efficiency of around 15.9% at 60 K, which is the highest efficiency ever reported for a coaxial pulse tube cryocooler.     

Performance of superconducting nanowire single photon detection system with different temperature variation

The performance of cryocooler-based superconducting single photon detection system suffers from the intrinsic temperature oscillation, which is typically ∼300 mK around 4.2 K originated from the periodic expansion of the cryocooler’s working fluid (He). By using a rare-earth alloy (ErNi) plate with a high heat capacity at cryogenic temperatures in between the cold head of the cryocooler and the detector block, the detector temperature variation is successfully damped to be less than 10 mK. The dark count rate is reduced and the maximum working bias current is increased. The quantum efficiency of SNSPD system is significantly improved by 40%.     

Design and qualification of the AMS-02 flight cryocoolers

Four commercial Sunpower M87N Stirling-cycle cryocoolers will be used to extend the lifetime of the Alpha Magnetic Spectrometer-02 (AMS-02) experiment. The cryocoolers will be mounted to the AMS-02 vacuum case using a structure that will thermally and mechanically decouple the cryocooler from the vacuum case. This paper discusses modifications of the Sunpower M87N cryocooler to make it acceptable for space flight applications and suitable for use on AMS-02. Details of the flight model qualification test program are presented.AMS-02 is a state-of-the-art particle physics detector containing a large superfluid helium-cooled superconducting magnet. Highly sensitive detector plates inside the magnet measure a particle’s speed, mass, charge, and direction. The AMS-02 experiment, which will be flown as an attached payload on the International Space Station, will study the properties and origin of cosmic particles and nuclei including antimatter and dark matter.Two engineering model cryocoolers have been under test at NASA Goddard since November 2001. Qualification testing of the engineering model cryocooler bracket assembly including random vibration and thermal vacuum testing was completed at the end of April 2005. The flight cryocoolers were received in December 2003. Acceptance testing of the flight cryocooler bracket assemblies began in May 2005.     

Parameter effect analysis for a Stirling cryocooler

In this paper, an isothermal model is used for modeling the Stirling cryocooler. Various losses including regenerator imperfection thermal loss, piston finite speed loss, gas spring hysteresis loss, displacer shuttle heat loss, clearance heat pump loss, heat conduction loss, and flow viscosity loss are taken into consideration at the same time step, as they could interact with each other. Energy and exergy balance analysis of the cryocooler shows that the mechanical friction loss is the biggest mechanical loss; conduction loss is the biggest heat loss. Effects of parameters consisting of cold end temperature, hot end temperature, average pressure, rotation speed, displacer clearance size, phase shift between piston and displacer, and ratio between diameter and stroke of piston on the cryocooler's performance are investigated. It shows that, there is optimum displacer clearance size, optimum phase shift between piston and displacer, and optimum ratio between diameter and stroke of piston for the studied cryocooler. The isothermal model was verified by the PPC-102 Stirling cryocooler.