100Hz以上微型脉冲管制冷机的理论与实验研究

发布时间：2018-07-09 19:05

本文选题：微型脉冲管制冷机 + 100　；参考：《中国科学院大学(中国科学院上海技术物理研究所)》2017年博士论文

【摘要】：近年来微型化制冷技术迅速发展,其中微型脉冲管制冷机有望取代微型斯特林制冷机和JT制冷机,为航空、航天及地面战术等特殊应用场合的红外光电系统提供快速有效及长寿命的冷却。为了弥补国内在该领域内的研究不足,并为独立自主地完成相关空间和国防任务提供坚实可靠的基础,本文以理论模拟与实验测试为基础,对100 Hz以上微型脉冲管制冷机开展了系统的研究。主要研究内容及结论如下:(1)对微型动圈式线性压缩机进行了系统的理论研究,在此基础上研发出谐振频率高达130 Hz的微型线性压缩机,质量从8 kg降至1 kg。在整体缩放原理的基础上,提出了压缩机部分关键部件的微缩修正。基于本研究组研发的300 W中型压缩机,运用修正缩放原理研制了一台微型动圈式线性压缩机,共振频率从55 Hz提高至130 Hz,最大输入电功可达63 W,质量从8 kg降至1 kg。之后将微型压缩机与中型脉冲管冷指耦合,在130 Hz的运行频率及60W的输入电功下测试制冷性能与压缩机特性。验证了中型冷指的阻抗难以与微型压缩机相匹配,因此必须重新设计微型脉冲管冷指。(2)建立了微型直线电机磁场结构的理论模型,并对其磁场分布进行了实验验证。建立了微型压缩机直线电机磁场结构的三维理论模型,研究了气隙宽度等关键尺寸参数对气隙内磁通密度分布的影响,并进行了实验验证。实际磁通密度的分布趋势与模拟结果基本一致,并对理论与实验误差进行了分析。本研究从另一角度验证了修正缩放原理的合理性。(3)建立了100 Hz以上微型脉冲管制冷机的二维CFD理论模型。建立了100 Hz以上微型同轴式脉冲管制冷机的二维轴对称CFD模型,分别采用热平衡及非热平衡模型预测了整机的制冷性能,模拟了两种模型下的压降损失、不完全换热损失、气体及固体导热损失沿蓄冷器的轴向分布等变化规律,对各项熵产的变化原因均进行了详细的分析。(4)系统研究了90~170 Hz的高频下运行频率对微型脉冲管制冷机的影响。基于脉冲管内部温度场和流场的分析结果,讨论了90~170 Hz高频下运行频率与脉冲管长度对脉冲管内传热传质过程的影响。当冷指尺寸一定时整机存在最优频率;当频率过低时会导致冷热流体的强烈混合,严重恶化制冷性能;而当频率过高时脉冲管中部会出现较大的径向温度梯度,在一定程度上降低了制冷性能,此时换用更短的脉冲管可以大幅改善传热传质过程。(5)系统研究了混合丝网填充下蓄冷器的内部损失机制。为了验证上述理论模型的合理性,基于本研究组的单级同轴式脉冲管制冷机建立二维CFD模型,讨论了混合丝网填充下蓄冷器的内部损失机制,并进行了实验验证。随着丝网目数的增加,热端附近的压降损失显著提高,而冷端附近的不完全换热损失迅速下降。因此在蓄冷器的冷热两端附近分别换用目数更高和更低的不锈钢丝网,能够大幅降低蓄冷器内的总熵产,从而改善制冷性能。实验与模拟结果在变化趋势上具有较好的一致性。本研究为100 Hz以上微型脉冲管制冷机中蓄冷器的填料填充方案提供了理论指导。(6)研制出质量仅为1.3 kg的100 Hz以上微型脉冲管制冷机整机的实验样机,并对其性能进行了实验验证。基于上述理论研究,研制出一台100 Hz以上微型脉冲管制冷机的实验样机,整机质量降至1.3 kg。该样机在60 W的输入电功下最优运行频率为114 Hz,此时可以获得0.78 W/80 K的制冷量。冷端从初始温度300 K降至无负荷温度74.2 K需要7.5 min。微型压缩机的实际电机效率为71.0%。最后详细分析了实验与模拟结果之间出现误差的原因。
[Abstract]:Miniaturized refrigeration technology has developed rapidly in recent years, in which micro pulse control refrigerator is expected to replace the mini Stryn refrigerator and JT refrigerator, which provides fast and effective and long life cooling for infrared photoelectric systems in special applications such as aviation, space and ground tactics. On the basis of theoretical simulation and experimental test, a systematic study of 100 Hz micro pulse tube refrigerator is carried out on the basis of theoretical simulation and experimental testing. The main contents and conclusions are as follows: (1) the theoretical study of micro moving coil linear compressor is carried out on the basis of the research. A miniature linear compressor with a resonant frequency of up to 130 Hz has been made with the mass from 8 kg to 1 kg.. Based on the overall scaling principle, a miniature correction of the key parts of the compressor is proposed. Based on the 300 W medium compressor developed by this research group, a miniature moving coil type linear compressor is developed by using the modified scaling principle. The resonance frequency is from 5. 5 Hz is increased to 130 Hz, the maximum power input power can reach 63 W, and the mass from 8 kg to 1 kg., the micro compressor is coupled with the cold finger of the medium pulse tube, the performance and the compressor characteristics are tested under the operating frequency of 130 Hz and the input power of 60W. It is verified that the impedance of the medium cold finger is difficult to match with the miniature compressor. (2) a theoretical model of the magnetic field structure of a micro linear motor is established and its magnetic field distribution is verified experimentally. A three-dimensional theoretical model of the magnetic field structure of a miniature compressor linear motor is established, and the influence of the key size parameters, such as the width of the air gap, on the flux density distribution in the air gap is studied, and the experimental test is carried out. The distribution trend of actual magnetic flux density is in agreement with the simulation results, and the theoretical and experimental errors are analyzed. The rationality of the revised scaling principle is verified from another point of view. (3) a two-dimensional CFD theoretical model for the micro pulse tube cooler with more than 100 Hz is established. A miniature coaxial pulse control refrigerator with more than 100 Hz is built. The two dimensional axisymmetric CFD model is used to predict the refrigeration performance of the whole machine by using heat balance and non thermal equilibrium model respectively. The changes of pressure drop, incomplete heat transfer loss, gas and solid heat conduction loss along the axial distribution of the accumulator are simulated under the two models, and the changes of the entropy production are analyzed in detail. (4) The influence of the high frequency operating frequency of 90~170 Hz on the micro pulse tube refrigerator is investigated. Based on the analysis of the temperature field and the flow field inside the pulse tube, the influence of the operating frequency and the length of the 90~170 Hz on the heat and mass transfer process in the pulse tube is discussed. When the cold finger size is fixed, the optimal frequency is present; when the frequency is over, the frequency is over. Low temperature can cause a strong mixture of cold and hot fluids and seriously deteriorate the performance of refrigeration. When the frequency is too high, a larger radial temperature gradient will appear in the middle of the pulse tube, and the refrigeration performance is reduced to a certain extent. At this time, the transfer of a shorter pulse tube can greatly improve the heat and mass transfer process. (5) the system has studied the accumulator under the mixed screen filling. In order to verify the rationality of the theoretical model, based on the establishment of a two-dimensional CFD model of the single stage coaxial pulse tube cooler in this research group, the internal loss mechanism of the cold accumulator under the mixed screen filling is discussed and the experimental verification is carried out. With the increase of the mesh mesh, the pressure drop near the hot end increases significantly and is cold. The loss of incomplete heat transfer in the vicinity of the end is reduced rapidly. Therefore, the use of higher and lower mesh of stainless steel wire in the vicinity of the cold and hot ends of the accumulator can greatly reduce the total entropy production in the cooler, thus improving the refrigeration performance. The experimental and simulation results have a good consistency in the changing trend. This study is more than 100 Hz minitype. The filling filling scheme of the accumulator in the pulse control refrigerator provides theoretical guidance. (6) the experimental prototype of a micro pulse tube refrigerator with a quality of only 1.3 kg is developed and its performance is verified experimentally. Based on the above theory, an experimental prototype of a micro pulse control refrigerator with more than 100 Hz is developed and the whole machine is developed. The quality is reduced to 1.3 kg. and the optimal operating frequency is 114 Hz under the input power of 60 W. The cooling capacity of 0.78 W/80 K can be obtained at this time. The cold end from the initial temperature 300 K to the non load temperature 74.2 K needs the actual motor efficiency of the 7.5 min. micro compressor to be 71.0%. at the end of the detailed analysis of the error between the experiment and the simulation results. Reason.
【学位授予单位】：中国科学院大学(中国科学院上海技术物理研究所)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TB651

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