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热耦合二级Stirling型脉管制冷机的性能研究 总被引:3,自引:2,他引:1
建立热耦合二级Stirling型脉管制冷机实验装置.通过实验,系统研究了交变流动工质的工作频率和平均工作压力对热耦合二级Stirling型脉管制冷机性能的影响,详细报道并分析讨论了实验结果.以氦气作为工质,在优化工作频率和平均工作压力条件下,热耦合二级Stirling型脉管制冷机获得了13.52 K的无负荷制冷温度. 相似文献
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热声驱动脉管制冷机通常采用直接或者长管耦合的方式,但是因为耦合后的发动机和制冷机难以达到最佳的工作状态,耦合长管的损失也比较大,因此整体效率较低。本文提出一种热声驱动脉管制冷机结构,利用谐振子耦合热声发动机和脉管制冷机,能够显著减小声功传递损失,提升整机效率。全文针对在900 K加热温度、80 K空气液化温区下的热声驱动脉管制冷机展开理论研究,首先分析了谐振子耦合机理,并对谐振子参数进行了优化设计;其次,研究了加热温度、制冷温度和机械阻尼对系统性能影响;最后,将谐振子耦合型与长管耦合型两种方式的热声驱动制冷机进行了对比分析。结果表明:在平均压力为3MPa,加热温度为900 K,制冷温度为80 K时,谐振子耦合的热声驱动制冷机可获得整机22.5%的效率,而长管耦合的热声驱动脉管制冷机获得11.6%的效率。 相似文献
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采用丙纶纤维作为回热器新型填充介质,对单级脉管制冷机进行了试验研究。对丙纶微尺度空间结构及物理性能进行了分析,基于充气压力分别为3.5、3.0、2.8、2.5、2.0、1.5 MPa的工况下,进行了降温性能、频率性能、制冷性能试验,获取了最低制冷温度,最佳工作频率及最大比卡诺效率。研究结果表明,充气压力对丙纶填充回热器的制冷机整体性能影响较大,工作频率的影响不是很明显。最终获得了最大比卡诺效率9.46%@170 K/10.06 W/77 W,最大制冷量为5.47 W@120 K/2.5 MPa,12.02 W@150 K/3.0 MPa,16.49 W@170 K/3.0 MPa,并获得了96.4 K的最低制冷温度。 相似文献
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级间热桥的传热特性对于热耦合型多级脉管制冷机的制冷温度和制冷效率均具有重要影响。采用铜丝编织带和铜箔连接的3种热桥进行对比实验,研究了热桥的传热特性对热耦合二级Stirling型脉管制冷机性能的影响。采用改进后的热桥,以氦气作为工质,在总输入电功率为400W,以及优化的工作频率和充气压力条件下,热耦合二级Stirling型脉管制冷机实现了12.96K的无负荷制冷温度,并可同时在23.1K和100.8K分别提供0.4W和6W的制冷量。 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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The pulse tube cooler (PTC) driven by a thermoacoustic engine can completely eliminate mechanical moving parts, and then achieves a simpler and more reliable device. A Stirling thermoacoustic heat engine has been constructed and tested. The heat engine can generate a maximal pressure ratio of 1.19, which makes it possible to drive a PTC and get good performance. Frequency is one of the key operating parameters, not only for the heat engine but also for the PTC. In order to adapt to the relatively low design frequency of the PTC, the operating frequency of the thermoacoustic heat engine was regulated by varying the length of the resonance tube. Driven by the thermoacoustic engine, a single stage double-inlet PTC obtained the lowest refrigeration temperature of 80.9 K with an operating frequency of 45 Hz, which is regarded as a new record for the reported thermoacoustically driven refrigerators. 相似文献
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《低温学》2002,42(3-4):223-227
Frequency matching is of great importance to a thermoacoustically driven pulse tube refrigeration system. To compute the resonance frequency of thermoacoustic engines, the fluid impedance method is introduced. The calculations of the thermoacoustic engines with different arrangements of buffer have been carried out. The influence of the buffer arrangements and the volume on the resonance frequency as well as the acoustic power of thermoacoustic engines is also discussed. 相似文献
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A resonance tube is an important component of a thermoacoustic engine, which has great influence on the performance of the thermoacoustically driven pulse tube refrigerator. A standing wave thermoacoustic engine is simulated with linear thermoacoustics. Computed results show that an appropriate accretion of the resonance tube length may lead to a decrease of the working frequency and an increase of the pressure amplitude, which will improve the match between the thermoacoustic engine and the pulse tube refrigerator. The theoretical prediction is verified by experiments. A refrigeration temperature as low as 88.6 K has been achieved with an optimized length of the resonance tube, helium as working gas, and 2200 W of heating power. 相似文献
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After the modifications of jacket type water coolers and stacks, and the optimizations of the openings of orifice and double inlet valves, a refrigeration temperature as low as 115.4 K has been achieved by a thermoacoustically driven pulse tube refrigerator. By operating the double inlet valve of the pulse tube refrigerator, the onset temperature of the thermoacoustic system decreases from 550 to 340 °C. It provides the possibility of utilizing the low-grade heat energy. 相似文献
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《低温学》2015
A 300 Hz pulse tube cryocooler (PTC) driven by a three-stage traveling-wave thermoacoustic heat engine (TSTHE) has been proposed and studied in this paper. In the configuration, three identical thermoacoustic heat engine units are evenly incorporated in a closed traveling-wave loop, in which three pulse tube cryocoolers are connected to the branch of each thermoacoustic heat engine. Compared with the conventional thermoacoustic heat engine which involves a traveling-wave loop and a long resonator, it has advantages of compact size and potentially high thermal efficiency. A TSTHE–PTC system was designed, optimized and studied in detail based on the thermoacoustic theory. Firstly, numerical simulation was conducted to design the system thus the optimum structure parameters of the system were obtained. With the operating condition of 4 MPa mean pressure and high working frequency, a cooling power of 7.75 W at 77 K and an overall relative Carnot efficiency of 11.78% were achieved. In order to better understand the energy conversion characteristics of the system, distributions of key parameters such as acoustic work, phase difference, dynamic pressure, volume flow rate and exergy loss were presented and discussed. Then, the coupling mechanism of the system was investigated. In addition, influence of coupling position on the system performance was further studied. 相似文献
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一种提高热声发动机压比的"声学变压器" 总被引:1,自引:1,他引:0
针对目前低温热声制冷机的驱动压比比较低的现状,提出了一种连接在热声发动机与制冷机之间的一种变压装置.热声发动机产生的压力波动在经过此变压器进行"变压"后,波动压力幅值大幅升高.对此方案设计了原理性的实验,表明声波在经过此变压器之后压力幅值能够提高3倍左右,充分证明此变压器具有大幅度提高压力幅值的能力. 相似文献
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