共查询到19条相似文献,搜索用时 101 毫秒
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叙述了用以提高多级脉管制冷机的工作性能和系统简单化的新结构.为减少国热器的损失和脉管冷损,在从室温到液氦温区内工作的脉管制冷机中引入了回热管.采用这种结构的三级制冷机达到了3.6K的最低温度,4.9K时制冷量为119mW.给出了该脉管制冷机的实验结果和制冷性能. 相似文献
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介绍了自行研制的双小孔型二级脉管制冷机的制作工艺及调试方法,并指出实验过程中必须注意的事项。用该脉管制冷机已获得液氦温度,第二级制冷温度为3.1K。 相似文献
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脉管制冷机特征线数值分析方法 总被引:1,自引:1,他引:0
提出运用特征线方法数值计算脉管制冷机的内部流动,提出相应离散方法,数值计算方法和特征线边初值问题的处理方法。算例结合实验进行验证,并论述了脉管制冷机部流动特征线数值分析方法的数理意义。 相似文献
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切换式脉管制冷机的性能分析 总被引:1,自引:0,他引:1
切换式脉管制冷机用于天然带压气源获取冷量,具有一定的优势。本文着重在理论数值分析上对其性能进行了研究,建立了切换式脉管制冷机的数学模型,对制冷机内部过程进行了数值模拟计算,并用实验验证数值分析的可靠性,计算结果揭主要结构参数和操作参数同性能指标的关系,理论数值分析的切换式脉管制冷机的进一步结构优化提供了具有重要的参考价值的依据。 相似文献
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在考虑20K以下温区氦流体热物性特点的基础上,本文建立了液氦温区脉管制冷机的经热模型,用以研究液氦温区双向进气型脉管制冷机的动态工作过程及其制冷机理,为开展液氦温区多级脉管制冷机的实验研究提供了理论依据。 相似文献
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介绍最近研制的一台双向进气带第二小孔阀型二极脉管制冷机实验情况。该机采用计算机时序控制,脉管热端均处于室温。文中给出了二级脉管制冷机的基本结构尺寸以及试验结果;一级脉管达到45K;二级脉管无负荷最低制冷温度达到3.1K。能稳定,长期工作,讨论了制冷机性能的主要因素。 相似文献
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分析了在自行研制的双小孔型二级脉管制冷机实验过程中回热器对脉管制冷机性能的影响,给出了合理的回热器布置方式,讨论了回热器形变及压缩机油污染对脉管制冷机性能的影响,指出了羊毛毡在隔离磁性材料Nr3Ni粉尘中所起的重要作用。在优化改进的基础上,该机达到了3.1K的最低无负荷温度。 相似文献
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在焓流理论的基础上提出脉管制冷机的线性气流速度分析法,该方法着重求解脉管内气流速度的幅值和相位,给出的公式简单,概念直观,计算量少。对基本型、小孔型和双向进气型脉管进行了分析,获得的结果与数值模拟结果相似,说明了这是一种行之有效的分析方法。 相似文献
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脉管在脉管制冷机中所起的作用,主要体现在热力学和动力学两方面。由热力学平衡计算可决定脉管制冷机的尺寸,但同时也要进行动力学上的匹配。着重利用Dr.deBoer的热力学分析方法对脉管内的气柱位移进行了定量计算 ,给出了计算结果 ,并进行了讨论 相似文献
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分离型二级脉管制冷机的实验研究第一部分20~40 K温区单级大功率脉管制冷机 总被引:3,自引:3,他引:0
为了满足液氦温区分离型二级脉管制冷机第二级预冷的需要,设计制作了1台20~40K温区单级大功率脉管制冷机.采用额定功率为6 kW的压缩机驱动该制冷机,最低制冷温度达13.8K,刷新了单级脉管制冷机最低制冷温度纪录.该制冷机在40 K可获得高达55.9 W的制冷量,基本可以满足15~40 K温区超导磁体等冷却的需要.着重分析了频率、充气压力和不同压缩机对系统制冷性能的影响,测试了长时间运行中系统性能的变化情况. 相似文献
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A nodal analysis method for simulating inertance tube pulse tube refrigerators is introduced. The energy equation, continuity equation, momentum equation of gas, energy equation of solid are included in this model. Boundary condition can be easily changed to enable the numerical program calculate thermal acoustic engines, inertance tube pulse tube refrigerators, double inlet pulse tube refrigerators, and others. Implicit control volume method is used to solve these equations. In order to increase the calculation speed, the continuity equation is changed to pressure equation with ideal gas assumption, and merged with momentum equation. Then the algebraic equation group from continuity and momentum equation becomes one group. With this numerical method, an example calculation of a large scale inertance tube pulse tube refrigerator is shown. 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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A numerical method for regenerators is introduced in this paper. It is not only suitable for the regenerators in cryocoolers and Stirling engines, but also suitable for the stacks in acoustic engines and the pulse tubes in pulse tube refrigerators. The numerical model is one dimensional periodic unsteady flow model. The numerical method is based on the control volume concept with the implicitly solve method. The iteration acceleration method, which considers the one-dimensional periodic unsteady problem as the steady two-dimensional problem, is used for decreasing the calculation time. By this method, the regenerator in an inertance tube pulse tube refrigerator was simulated. The result is useful for understanding how the inefficiency of the regenerator changes with the inertance effect. 相似文献
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In high-power pulse-tube refrigerators, the pulse tube itself can be very long without too much dissipation of acoustic power on its walls. The pressure amplitude, the volume-flow-rate amplitude, and the time phase between them evolve significantly along a pulse tube that is about a quarter-wavelength long. Proper choice of length and area makes the oscillations at the ambient end of the long pulse tube optimal for driving a second, smaller pulse-tube refrigerator, thereby utilizing the acoustic power that would typically have been dissipated in the first pulse-tube refrigerator’s orifice. Experiments show that little heat is carried from the ambient heat exchanger to the cold heat exchanger in such a long pulse tube, even though the oscillations are turbulent and even when the tube is compactly coiled. 相似文献
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This paper proposes and describes a compact work-recovery phase shifter of a pulse tube refrigerator. Most pulse tube refrigerators recently developed utilize a long inertance tube and a reservoir for phase control between dynamic pressure and mass flow rate at the cold-end of pulse tube refrigerators. An inertance tube-type phase shifter (long inertance tube and reservoir), however, sometimes creates a problem of compact packaging in cryocooler applications and dissipates the work transferred from a compressor as heat. To overcome this disadvantage, an inertance tube-type phase shifter is replaced with a compact work-recovery phase shifter composed of a mass–spring–damper system and a linear generator in a pulse tube refrigerator. This process is achieved by using analogy of the inertance tube-type phase shifter and the mass–spring–damper system. This paper describes a specific configuration of the designed compact work-recovery phase shifter. Using the simulation code, the performance of the pulse tube refrigerator with the compact work-recovery phase shifter is estimated. As a result, the pulse tube refrigerator with the compact work-recovery phase shifter has the comparable cooling capacity with the pulse tube refrigerator with the inertance tube-type phase shifter. If the recovery work is properly utilized, it can also achieve higher efficiency than that of the pulse tube refrigerator with a typical inertance tube-type phase shifter. In this paper, the parametric study of the mass, the spring and damper coefficients of the compact work-recovery phase shifter has been done and their effects are specifically evaluated. 相似文献