共查询到19条相似文献,搜索用时 93 毫秒
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斯特林型高频脉冲管制冷机的实验研究 总被引:1,自引:0,他引:1
介绍了一台单级U型高频脉冲管制冷机的实验装置和实验结果.制冷机冷端无负荷最低温度达到了38.31 K,此结果为目前国内单级斯特林型高频脉冲管制冷机所达到的最低温度.当输入电功率200 W时,在50 K有0.6 W制冷量;当输入电功率为250 W时,在80 K有4.25 W的制冷量.这为40 K以下深低温,大冷量的斯特林型脉冲管制冷机的研制做出了有益的探索.通过分析压缩机运行频率对制冷机的最低温度和制冷量的影响,得出了在液氮温区针对特定的制冷温度,压缩机存在的一个最佳工作频率.在此工作频率下,压缩机和脉冲管耦合后,制冷机能够获得较高的效率. 相似文献
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对GM型脉冲管制冷机及其旋转阀系统进行热力学分析,针对脉冲管内压力波为正弦波形的情况,推导出了制冷系数(COP)的理论公式,给出了COP的定量结果,并与斯特林型脉冲管制冷机进行了对比,结果发现,由于气体在旋转阀中的不可逆损失,使得压缩机功耗增大,降低了GM型脉冲管制冷机的COP,双向进气的效果取决了温降比,在较低的制冷温度(较大的TH/TL)时作用更加明显。 相似文献
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分析了脉冲管制冷机系统中存在的主要干扰源 ,并给出了其相应的解决方法 ,在此基础上设计并制作了一台无磁非金属微型同轴脉冲管制冷机。常规脉冲管制冷机中由磁性或金属材料所产生的电磁干扰和感应涡流 ,是将微型脉冲管制冷机应用到高灵敏度高温超导量子干涉仪冷却上的最大障碍。作者采用一系列无磁非金属电绝缘的材料完全替代脉冲管中的磁性或金属材料 ,以实现脉冲管制冷机的低电磁干扰化、甚至无电磁干扰化 ,并最终实现利用脉冲管制冷机 ,有效冷却包括高温超导量子干涉仪在内的对电磁干扰要求极严格的高温超导器件 相似文献
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通过对脉管型斯特林制冷机的分析和讨论,提出了此类制冷机的物理模型,对能量方程进行了推导,并编制了程序。计算结果显示,脉管斯特林制冷机在较高的制冷温区比单纯的斯特林制冷机有更大的制冷系数和更高的制冷量。 相似文献
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A three-stage Stirling pulse tube cryocooler operating below the critical point of helium-4 总被引:1,自引:0,他引:1
Precooled phase shifters can significantly enhance the phase shift effect and further improve the performance of pulse tube cryocoolers. A separate three-stage Stirling pulse tube cryocooler (SPTC) with a cold inertance tube was designed and fabricated. Helium-4 instead of the rare helium-3 was used as the working fluid. The cryocooler reached a bottom temperature of 4.97 K with a net cooling power of 25 mW at 6.0 K. The operating frequency was 29.9 Hz and the charging pressure was 0.91 MPa. It is the first time a refrigeration temperature below the critical point of helium-4 was obtained in a three-stage Stirling pulse tube cryocooler. 相似文献
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《低温学》2017
This paper presents experimental results and numerical evaluation of a Vuilleumier (VM) type pulse tube cryocooler. The cryocooler consists of three main subsystems: a thermal compressor, a low temperature pulse tube cryocooler, and a Stirling type precooler. The thermal compressor, similar to that in a Vuilleumier cryocooler, is used to drive the low temperature stage pulse tube cryocooler. The Stirling type precooler is used to establish a temperature difference for the thermal compressor to generate pressure wave. A lowest no-load temperature of 15.1 K is obtained with a pressure ratio of 1.18, a working frequency of 3 Hz and an average pressure of 2.45 MPa. Numerical simulations have been performed to help the understanding of the system performance. With given experimental conditions, the simulation predicts a lowest temperature in reasonable agreement with the experimental result. Analyses show that there is a large discrepancy in the pre-cooling power between experiments and calculation, which requires further investigation. 相似文献
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《低温学》2018
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. 相似文献
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The pulse tube belongs to the class of miniature cryogenic refrigerators usually referred to as cryocoolers. In common with Stirling and Gifford-McMahon machines, operation depends on a regenerative gas expansion cycle but unlike these coolers the pulse tube has no moving parts at low temperature and hence offers the potential for high reliability. Although comparisons may be drawn between the operation of a pulse tube and that of a Stirling cooler, the exact nature of the working cycle is far from clear and the device continues to intrigue. We provide here an introduction to the device and attempt to explain it's operation as a conventional second law system. 相似文献
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《低温学》2018
A Stirling/pulse tube hybrid cryocooler (SPC), comprised of a Stirling cryocooler as the first stage and a pulse tube cryocooler as the second stage, features the ability of shifting cooling capacity between stages by adjusting the movement of the displacer in the first stage. Such an ability allows an SPC to accommodate itself to time-varying heat loads at different temperatures, which makes it a competitive candidate in space applications. However, due to the gas coupling, there exists a significant mutual effect between stages which endows an SPC with special thermodynamic characteristics and has a significant effect on the SPC’s capability of shifting cooling capacity between stages. With the phasor analysis and the thermodynamic analysis, this paper establishes an idealized model of an SPC. The model is then used to study the effect of the second stage on the first stage and reveal the condition that an SPC is able to shift cooling capacity between stages. Also, the model is compared with a Sage numerical model and the two models are consistent on the overall trend. Though it is unable to reflect reality precisely, the idealized model can interpret the mechanism and highlight some of the essential nature of an SPC, which will eventually benefit the appropriate design of an SPC. 相似文献
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《低温学》2017
VM type pulse tube cryocooler is a new type pulse tube cryocooler driven by the thermal-compressor. This paper presented the recent experimental results on a novel single-stage VM type pulse tube cryocooler with multi-bypass. The low temperature double-inlet, orifice and gas reservoir, and multi-bypass were used as phase shifters. With the optimal operating frequency of 1.6 Hz and optimal average pressure of 1.4 MPa, a no-load temperature of 4.9 K has been obtained and 30 mW@5.6 K cooling power has been achieved. It was the first time for the single-stage VM-PTC obtaining liquid helium temperature reported so far. Moreover, it was also the first time for the multi-bypass being used in the low-frequency Stirling type pulse tube cryocooler. 相似文献
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《低温学》2018
The inertance tube plays a significant role in improving the performance of the Stirling type pulse tube cryocooler by providing the desired phase angle between the mass flow and pressure wave. The phase angle is highly depended on the inertance tube geometry, such as diameter and length. A cylindrical threaded root device with variable thread depth on the outer screw and inner screw creates an adjustable inertance tube whose diameter and length can be adjusted in the real time. However, due to its geometry imperfectness, the performance of this threaded inertance tube is reduced by the leaks through the roots between the two screws. Its phase angle shift ability is decreased by 30% with the leakage clearance thickness of 15.5 μm according to both the theoretical prediction and the experimental verification. 相似文献
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A one-dimensional finite volume discretization method is proposed and is implemented as a computer program for the modeling of a family of stirling type Pulse Tube Cryocoolers (PTC). The set of unsteady, one-dimensional, viscous compressible flow equations are written in a general form such that all, porous and non-porous, sections of the PTC can be modeled with these governing equations. In present work, temperature dependency of thermo-physical properties are taken into account as well as the heat transfer between the working fluid and the solid parts, and heat conductions of the gas and solid. The simulation tool can be used to model both the inertance tube type and the orifice type cryocoolers equipped with regenerators made up of different matrix constructions. The PTC might have an arbitrary orientation with respect to the gravitational field. By using the computer program, an orifice type and an inertance tube type pulse tube cryocooler are simulated. Diameter of the orifice and length of the inertance tube are optimized in order to maximize the coefficient of performance. Furthermore, the cooling power of the two types is obtained as a function of the cooling temperature. The behavior of thermodynamic parameters of the inertance tube PTC is investigated. Mean cyclic values of the parameters are presented. 相似文献