为研究回热器中填充结构的微观结构特征,基于多孔介质分形理论,使用压汞法对回热器孔隙分布情况及分形维数进行研究.回热器是微型斯特林制冷机的关键部件,使用不锈钢网片或不锈钢毡填充制备的回热器是一种典型的多孔介质.采用压汞法对回热器进行微观结构测试,得出回热器内部孔隙分布范围.结合多孔介质分形分析的基础理论,计算得出回热器分形维数,说明了回热器具有分形特征,得出回热器的分形维数区间.

为分析斯特林制冷机间隙密封泄漏量影响因素权重,结合同心环形缝隙流动理论,确定影响因素包括间隙厚度、密封长度、间隙两端压差、转速、间隙内径以及活塞冲程.通过正交试验搭建32组数学模型,基于计算流体CFD数值模拟的方法,研究分析不同密封间隙的泄漏情况.利用方差分析对仿真结果进行处理,结果表明间隙厚度对斯特林制冷机的泄漏量影响最大;压差、密封长度、活塞冲程以及转速对泄漏量影响依次减小;间隙内径对泄漏量影响最小.这对斯特林制冷机间隙密封减小泄漏量的设计提供了参考.

微机电系统MEMS(micro-electro-mechanical system)是一种集合了微电子与机械工程技术的新型高科技装置,其制造工艺可以进行最小至纳米尺度的加工以及高度集成化的微型制造.其产品微小体积、高度集成化以及高性能高产热的特性也决定了其需要匹配相应的制冷解决方案,本文重点阐述了基于MEMS制造工艺并同时应用于MEMS产品的微型制冷器的工作原理、性能及发展趋势.分别分析了微型半导体制冷器以及微型节流制冷器各自的优势和不足,对微型制冷器的未来发展提出了建议.

芯片级节流制冷器（MMR）是一种采用独特的微加工工艺制成的微型节流制冷器,其结构微小,最小体积可达15 mm×2 mm×0.5 mm。MMR在制冷量需求较小的微型元件冷却领域有着广泛的应用。介绍了MMR制造工艺的发展历程,分析了MMR的不同材料的选择、刻蚀方法、制冷器片密封方法以及制冷器气路、电路连接方法的特点,对比了各个工艺方法的优势和不足,并初步进行了MMR的制造加工和性能实验,得到了能够在7 MPa下稳定工作的MMR样品,并实现了32.6 K的制冷温降。对MMR工艺技术的改进和未来发展提出了一些建议。

Miniature Joule-Thomson cryocoolers have been widely used for rapid cooling of infrared detectors,cryo-surgery probes,thermal cameras,and missile guidance homing systems,due to their special features of simple configura-tion,compact structure and rapid cooldown characteristics.The thermodynamic performance of the J-T refrigerator depends upon the hydraulic and heat transfer characteristics of the recuperative heat exchanger.database is used to account for the real gas effects.The thermodynamic characteristics of the finned-tube Heat Exchanger are well revealed,based on this,the optimization analysis of miniature J-T cryocooler is carried out.The influences of mass flow rate and the length of heat exchanger on the effectiveness of heat exchanger and the ideal cooling capacity are discussed in details.

The Hampson-type miniature Joule-Thomson cryocooler is widely used in IR detectors and electronic cool-ing.The research progress of steady-state and transient characteristics of the Hampson-type miniature J-T cryocooler is ex-pounded respectively.It is pointed out in this paper that some effects have not been taken into account in the research of Hampson-type miniature Joule-Thomson cryocooler,they include:changes in fluid properties,heat exchange with the sur-rounding(heat leakage),longitudinal thermal conduction in the wall,and flow maldistribution. Besides,this paper also made some suggestions about whether we should consider these effects.Finally,some measures to make the Hampson-type miniature Joule-Thomson cryocooler model more accurate were put forward.

微型节流制冷器因其快速冷却、结构简单紧凑等特性而被广泛地应用在红外探测器、超导量子干涉器件等器件的冷却当中.由于目前的仿真计算仍然存在较大的误差,本文通过搭建实验平台,对微型J-T制冷器的稳态特性比如背压和稳定工作温度等进行了实验研究,制冷工质分别为氮气及氩气.实验结果表明,不同结构参数(比如换热器轴向长度、翅片间距)以及不同工况(比如不同的环境压力等)均会对制冷器的稳态特性产生较大影响.

Due to the advantages of low vibration and long MTTF,Free Piston Stirling Cooler(FPSC)can be uesed to cool down the infrared detectors. With the development of the High Operation Temperature detector(HOT detector),re-duction of size,weight,power along with higher performance and lower price is needed for the stirling cooler,which can be defined as micor-miniature stirling cooler. In this paper,we summarized the development of the micro-miniature FPSC at home and abroad in recent ten years,and introduced it's design balance. One novel micro-miniature FPSC prototype de-veloped by Kunming Institute of Physics is also shown in this paper.

The starting-up process of a J-T cooler is unsteady process. There is still a large error in the simulation of a J-T cooler's start-up process until now. Establishing the experimental model of different pitch finned tube heat exchanger to verify the effect on a J-T cooler start-up time. The experimental results show that the change of a heat exchanger fin pitch has impact on a J-T cooler start-up time,and the impact is not a linear relationship,there is an inflection point. In the model of this paper,the optimum pitch of fin tubes is 0.2 mm. The study is useful for the design of the J-T cooler.

As the key component of the linear Stirling cryocooler,the regenerator plays a vital role on the thermal performance.Based on the effect of the filled metal meshes on regenerators' thermal performance and the simulation results of REGEN3.3,three typical multi-metal-mesh filled regenerators were built and tested,which are assembled in linear Stirling cryocooler.The experimental results show that the regenerator,which have been multi-metal-mesh filled in a right way,can make a great thermal performance improvement of linear Stirling cryocooler.Finally,the cooling rate of the crycooler was improved by 14％,and the efficiency of cryocooler was improved by 37.5％.

微小型节流制冷器具有体积小、重量轻、可靠性高、启动速度快、冷端无运动部件等突出优势,在红外探测器、红外导引头以及其他电子器件冷却领域实现了大量应用.自调式节微型流制冷器特有的自调机构通过感应节流后温度变化来进行流量(制冷量)的调节,不仅能够有效利用有限的循环工质获得最大的制冷量,而且能够实现高的温度稳定性.为了实现对自调式微型节流制冷器自调机构形变的量化分析,指导自调机构波纹管选型,文中针对内充式自调机构充压波纹管建立了三维数值模型,采用变物性参数,分析了不同充注工质及不同波纹管材料下的低温条件形变特性.研究结果表明,所建立的数值分析模型预测结果与实际测量误差在5％以内,证实了模型的准确性.波纹管是自调机构发生形变的主要部件,除充注压力外,自调机构温度分布的不均匀,对于其形变特性也有一定影响.

With the advantages of small size,light weight,high reliability,quick start and the cold end without mov-ing part,miniature JT cryocooler is wildly applied in infrared seeker. Gas consumption is different for different types of J-T cooler. The volume,weight,working time of an infrared seeker bottle is determined by a JT cryocooler' s gas consump-tion. We have done some experimental research on Gas consumption about four kinds of Joule-Thomson Cooler in differ-ent condition. Some advices are supplied for different engineering applications by the research.

介绍了国外军用航空器搭载的红外搜索跟踪系统、红外对抗系统、导弹及对应的制冷机匹配情况.对目前国外空军使用的在产或在研的各种整体集成式斯特林制冷机、线性斯特林制冷机的特点进行了总结,指出制冷机的环境适应性与可靠性是制冷机最重要的发展特点.

IR imaging system on stabilized platform with gimbals is usually designed employing the linear cryocooler for small vibration. These systems trade off weight,size,and input power. Common rotary Stirling coolers take on bigger vibration than that of linear cooler though more efficient. The rotary cooler possessing parallel-axis layout could have a small effect on platform with high efficiency. This paper depicts the sources of self induced vibration and the characteristic of the stabilized platform. The rotary Stirling cooler is designed according to gimbals. Overturning moment can be coun-tered by the bearings in platform,and then the payload jitter smaller. The new rotary Stirling cooler is compatible with the stabilized platform.

Today’s rotary Stirling cryocooler controller is based on the PID control of brushless DC motor, which has issues such as control temperature fluctuation, lower reliability and so on. Permanent Magnet Synchronous Motor under Field Oriented Control has excellent control performance, smooth operation and low energy consumption. It is an effective way to improve Stirling cryocooler performance. Hardware and software are designed for this program. And practical circuit test results are given. Experiments show control systems based on FOC and PMSM can improve Stirling cryocooler performance.

By calculation and device optimization, a DSP as the core,hardware and software combination, a high-precision control circuit is designed, which achieves power and frequency continuously adjustable. Design, combination and functions of the circuit, as well as the actual test results, are described in this paper. With a wide range of power and frequency regulation, it can meet most of the linear stirling coolers’ driving and control needs at the present stage.

The vibrator in pneumatic expander of split-stirling cryocooler was analyzed and verified. With pneumatic rod area increases, vibrator's phase angle decreases, while stroke increases. The cooling capacity of Stepped-rod type was compared with direct-connected type's. The stepped-rod area rate will affect the matching of the expander to the compressor. The pressure ratio, phase angle and amplitude were considered to determine the area of the stepped-rod. The stepped-rod type expander’s wide frequency adapt characteristics is also analyzed.

Miniature Joule-Thomson cooler is widely applied for cooling infrared detector,it is a mature technology. The American company of ENDOCARE has invented the first generation of cryocare(Ar-He knife)systems in the 1990s. The cryocare(Ar-He knife)systems utilizes the Joule-Thomson effect. Its temperature will be rapidly cooled down by the high pressure argon expand from high pressure to low pressure at room temperature,and its temperature will be rapidly warmed up by the high pressure He expand from high pressure to low pressure at room temperature. Cancerous cells will be killed by the temperature exchange of cryocare (Ar-He knife) systems. The technology has been widely applied on cryosurgical and has achieved good therapeutic effect in the treatment of various cancers. Domestic miniature Joule Thom-son cooler technology has been carried out for many years and has accumulated a wealth of technical basis,but cryosurgi-cal is still in its initial stage. This paper presents low temperature medical has a broad development prospects in the future and gives an advocation to domestic companies to do more research on miniature Joule-Thomson cooler to promote the ap-plication of the cryosurgical technology in medical field.

The reliability of the tactical stirling cryocooler is a important performance. The paper introduces some basic reliability conception, and the prediction methods of reliability of RICOR, Thales cryogenics and BAE for the tactical stirling cryocooler. The reliability development of the tactical stirling cryocooler is detailed presented from the 1950s to nowadays in the paper. Finally the paper introduce some acceleration method of reliability for the tactical stirling cryocooler.

Changes of two dynamical factors would be induced when Matching Pneumatic Expander to the Linear Compressor, those are displacer’s natural frequency and motion damp. Experimental Study about the influence of the two dynamical factors on the cooling performance was made(the charging pressure is 1.8MPa ). Some conclusions were acquired: compressor’s resonant frequency was slightly affected by the displacer’s natural frequency and motion damp, so the effect could be ignored. The optimum ratio value of the operating frequency to the displacer’s natural frequency is about 0.7. Further more, the optimum ratio value reduces with the increment of the motion damp.