80K/2W斯特林制冷机全性能实验研究

80 K/2 W斯特林制冷机是上海技术物理研究所自行研制的分置式牛津型制冷机.为验证斯特林制冷机在各种工况下的广泛适应性,针对80 K/2 W制冷机进行实验,测试制冷机在不同压缩机行程、制冷温度以及环境温度下的全性能特性,总结斯特林制冷机部分实用的规律.     

5W@80K自由活塞斯特林制冷机工况及重力特性实验研究

利用现有的脉冲管制冷机性能测试实验台,针对某型号自由活塞斯特林制冷机,设计了热端水冷器并进行了性能测试.实验研究了工作频率、充气压力、输入功率等参数对制冷机性能的影响规律,结果表明斯特林制冷机的最佳运行工况为充气压力2.0 MPa,频率42 Hz.改变冷头在竖直方向和水平面不同的朝向,实验结果表明冷头竖直向下时最低制冷...     

气动型斯特林制冷机气动腔气体热力迟滞行为特性的理论分析

近年来，气体驱动斯特林制冷机在此重量、可靠性，振动和噪声等方面得到提高，在红外技术和超导电子学等领域具有诱人的应用前景，其研究工作一直是低温领域的一个热点，首先简要描述了气动型斯特林制冷机气动腔内气体热力迟滞行为特性，其次主要理论推导该部分气体热力迟滞行为特性造成的损失，并且给出了一个计算机仿真结果说明该项损失对制冷机性能的影响。本文对更为逼真地仿真微型气动斯特林制冷机的热动力特性行为提供了有力支撑。     

气动分置式斯特林制冷机被动减振技术研究

论述了斯特林制冷机的振动来源和振动特性,利用梁模型计算了冷指的自然频率,理论上给出了动力吸振器的设计方法,得出在气动分置式斯特林制冷机中被动减振方法具有优势.根据分析设计了动力吸振器,通过实验验证了动力吸振器可以有效的抑制制冷机地振动输出.     

工作参数对斯特林制冷机性能影响分析

在调试阶段影响斯特林制冷机性能的工作参数主要有:充气压力、工作频率和环境温度.其中充气压力和工作频率是最容易更改的参数,通过分析得到:充气压力影响着斯特林制冷机振子系统的自然频率,而工作频率则影响斯特林制冷机压机活塞和排除器的相位差.利用简化模型分析了环境温度对斯特林制冷机性能的影响.实验验证了充气压力、工作频率和环境温度对制冷机性能的影响,实验结果能较好的满足分析部分.     

脉管型斯特林制冷机的实验研究

对脉管型斯特林制冷机用于普冷的可行性进行了分析研究。用实验的方法对脉管到斯特林制冷机和单纯的斯特林制冷机的性能进行了对比，得出了在２４５Ｋ以上温区脉管型斯特林制冷机的性能优于单纯的斯特林制冷机的重要结论．对小孔和脉管长度变化对脉管型斯特林制冷机性能的影响进行了讨论．     

斯特林型脉冲管制冷机中压缩机与冷指耦合实验研究

从理论上分析了质量流和压力波对脉冲管制冷机中冷指和压缩机耦合的影响, 针对1台6 W/95 K斯特林型脉冲管制冷机行了具体研究.实验分析表明:只有当线性压缩机能够提供脉冲管冷指所需的压力波动和质量流量时,整机才可能取得较好的性能;运行频率和整机的输入功率对压缩机效率的影响都小于2%.     

排出器等效机械阻尼对自由活塞斯特林制冷机性能影响的数值模拟

针对一台设计目标为300 W@80 K自由活塞斯特林制冷机,数值计算研究了排出器等效机械阻尼R_m对制冷机性能的影响及其作用机理。研究发现,R_m对制冷机的影响主要有两方面,一是直接影响排出器处的摩擦损失,导致制冷机性能变化;其次是改变了系统的声场分布,导致其他核心部件如回热器和换热器的损失变化。此外,制冷机入口声阻抗特性随之发生变化并进一步影响制冷机与压缩机的耦合性能。计算结果表明,维持制冷机输入声功1 363 W不变,当R_m由25 Ns/m增大至100 Ns/m时,制冷机制冷量由194.7 W降低至160.9 W,相对卡诺效率由38.9%降低至32.2%。     

-80℃斯特林制冷机设计及实验研究

为满足低温存储领域对小型化、大冷量、高效率斯特林制冷机的应用需求,研究基于斯特林制冷机的特点,结合实际现状,设计了一台可用于低温存储领域的-80℃自由活塞式斯特林制冷机。根据其运行原理,通过数值模拟及实验验证重点分析了设备运行频率和工作压力对整机性能的影响,在此基础上讨论并提出了制冷机的优化思路。实验结果表明回热器采用丝网填充,工作压力为2.9 MPa,运行频率为63 Hz时,该制冷机在175.1 W输入功率下,可在-85℃提供29 W冷量输出,COP为0.166;当使用PET材料时,无热负载状态下最快可在42分钟左右冷端温度达到-86℃,其性能表现满足现有小型低温冰箱的冷量需求。通过数值模拟和实验结果的对比,讨论了出现性能差异的原因。     

自由活塞斯特林制冷机的研究与应用进展

对自由活塞斯特林制冷机(FPSC)的发展历史以及当前的研究进展进行总结,比较了自由活塞斯特林制冷机与分置式斯特林制冷机的性能,结果显示自由活塞斯特林制冷机的相对卡诺效率明显高于分置式斯特林制冷机。自由活塞斯特林制冷机具有高效、紧凑、制冷温区广等优势,分别从航天、超导、低温冰箱、家用制冷等方面详细总结了自由活塞斯特林制冷机应用情况。最后,根据自由活塞斯特林制冷机的发展现状,提出了一些有用的建议,对自由活塞斯特林制冷机的发展及应用具有一定指导意义。     

A study on the linear compressor characteristics of the Stirling cryocooler

The purpose of this study is to analyze the characteristics of the linear compressor for Stirling cryocooler. To ensure high performance and long life of the free piston, free displacer Stirling cryocooler, the operating parameters of the linear compressor should be optimized. The experimental results show the operating frequency of the linear compressor has significant effect to the input power characteristics, and the compressor with higher charging pressure of working fluid has high pressure ratio. For the high performance of the linear compressor, compressor has uniform magnetic force with different stroke, and the optimal operating frequency with respect to the charging pressure.     

Study on the phase shift characteristic of the pneumatic Stirling cryocooler

Due to entire pneumatic connection between free piston and free displacer, the motion parameters of them including amplitude and phase shift can actually impact the cooling capacity and overall performance of cryocooler obviously. In this study, the procedure of design and manufacture pneumatic free piston and free displacer (FPFD) Stirling cryocooler had firstly been described in details. Then in order to accomplish study, the experimental bench has been set up based on 80 K@1 W Stirling cryocooler. The effect of the thermodynamic and pneumatic parameters including charging pressure, natural frequency of displacer, damping coefficient of displacer, working frequency on the pressure, displacement and displacer phase shift has been investigated, respectively by means of experimental and theoretical method. In particular, the variation of damping is realized by adjusting the width of clearance cut on the additional damping component, which is screwed on the displacer rod. Similarly, natural frequency of displacer is changed by the extra mass connected on the displacer. Due to the results of experimental study, the optimum working conditions of this Stirling cryocooler for 80 K cold tip temperature are as follows: charge pressure 15 bar, natural frequency of displacer 46 Hz, width of clearance 300 μm and working frequency 43 Hz. In agreement with the optimum working conditions, neighborhood interval of 90° is the ideal working domain for displacement phase shift. Meanwhile, the displacer phase shift should approach to 0°as near as possible and pressure phase shift should also be as small as possible, which have linear relation with non-dimensional damping characteristic of compressor. In view of theoretical study, the expressions of three phase shifts deduced from thermodynamic equation of piston and displacer respectively are expressed as the functions of working parameters, which are verified by the experimental data and consequently can be used as the powerful guidance to optimum seeking.     

CFD modeling and experimental verification of oscillating flow and heat transfer processes in the micro coaxial Stirling-type pulse tube cryocooler operating at 90–170 Hz

This paper presents the CFD modeling and experimental verifications of oscillating flow and heat transfer processes in the micro coaxial Stirling-type pulse tube cryocooler (MCSPTC) operating at 90–170 Hz. It uses neither double-inlet nor multi-bypass while the inertance tube with a gas reservoir becomes the only phase-shifter. The effects of the frequency on flow and heat transfer processes in the pulse tube are investigated, which indicates that a low enough frequency would lead to a strong mixing between warm and cold fluids, thereby significantly deteriorating the cooling performance, whereas a high enough frequency would produce the downward sloping streams flowing from the warm end to the axis and almost puncturing the gas displacer from the warm end, thereby creating larger temperature gradients in radial directions and thus undermining the cooling performance. The influence of the pulse tube length on the temperature and velocity when the frequencies are much higher than the optimal one are also discussed. A MCSPTC with an overall mass of 1.1 kg is worked out and tested. With an input electric power of 59 W and operating at 144 Hz, it achieves a no-load temperature of 61.4 K and a cooling capacity of 1.0 W at 77 K. The changing tendencies of tested results are in good agreement with the simulations. The above studies will help to thoroughly understand the underlying mechanism of the inertance MCSPTC operating at very high frequencies.     

用于塑料制冷机叠片式排出器的研制

研制了一种由铝箔和玻璃钢片所织成的叠片式排出器，并在二级塑料制冷机中进行了对比试验。试验结果表明，叠片排出器制冷机的性能优于尼龙排出器的制冷机，前者的最低制温度比后者低７Ｋ左右，预冷时间缩短了４小时，制冷量也有明显增加。文中还比较了两种不同排出器的热物性，并对制冷机进行了热分析。     

Experimental study of a cascade pulse tube cryocooler with a displacer

Recovering the expansion power in pulse tube cryocooler is of great utility in improving cooling efficiency. Using a second-stage cooler after a primary cooler to produce extra cooling power is an effective way especially when the cooling temperature is not very low. In the configuration, the two coolers are connected by a displacer which is used as a phase shifter. In this paper, experimental investigations were conducted to study this system. Firstly, the performance of the overall system and separated cooler was respectively presented. To better understand the displacer, phase relation, mechanical resistance and displacement were then clarified. In addition, the power consumption distribution of the cascade cryocooler was discussed. Finally, both numerical and experimental comparisons were made on the displacer-type and tube-type cryocooler. The experimental results show that the displacer-type cryocooler has superior performance due to the better phase-modulation capability and less power loss. With the input electric power of 1.9 kW and cooling temperature of 130 K, the overall system achieved a cooling power of 371 W and a relative Carnot efficiency of 24.5%.     

10W/80K高频同轴脉冲管制冷机的实验性能

介绍了一款大冷量高频单级同轴脉冲管制冷机的基本结构、数值模拟和实验性能。其线性压缩机采用Redlich动磁式直线电机驱动,压缩活塞对置布置,使用板弹簧支撑和间隙密封技术,80 K温区工作时的电机效率在83%以上。膨胀机的蓄冷器和脉冲管为同轴型布置,这种结构使冷头与器件之间的耦合非常方便。使用数值软件对制冷机整机和调相部件进行数值模拟,并对模拟结果进行实验验证。对制冷机的运行频率和制冷性能进行实验研究,制冷机在210.3 W输入电功时能获得10 W/80 K的制冷性能,比卡诺效率为12.66%,运行频率为62 Hz,整机重量小于5.5 kg。     

Cascade pulse-tube cryocooler using a displacer for efficient work recovery

Expansion work is generally wasted as heat in a pulse-tube cryocooler and thus represents an obstacle to obtaining higher Carnot efficiency. Recovery of this dissipated power is crucial to improvement of these cooling systems, particularly when the cooling temperature is not very low. In this paper, an efficient cascade cryocooler that is capable of recovering acoustic power is introduced. The cryocooler is composed of two coolers and a displacer unit. The displacer, which fulfills both phase modulation and power transmission roles, is sandwiched in the structure by the two coolers. This means that the expansion work from the first stage cooler can then be used by the second stage cooler. The expansion work of the second stage cooler is much lower than the total input work and it is thus not necessary to recover it. Analyses and experiments were conducted to verify the proposed configuration. At an input power of 1249 W, the cascade cryocooler achieved its highest overall relative Carnot efficiency of 37.2% and a cooling power of 371 W at 130 K. When compared with the performance of a traditional pulse-tube cryocooler, the cooling efficiency was improved by 32%.     

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.     

一种4W/80K的整体式斯特林制冷器

介绍该所研制的４Ｗ／８０Ｋ整体式斯特林制冷器。它适用于超导滤波器、超导延迟线等组件,并已成功地应用于上述组件的研制工作中。同时亦适用于高温超导、低温物性测试等领域。按等温模型简述热力设计的机理及方法、制冷器的结构及压缩活塞－推移活塞同轴结构布置方案,制冷器性能特性,并进行分析讨论。同时介绍该成果的主要技术指标。