大功率动磁式线性压缩机关键技术与实验研究

发布时间：2018-03-03 07:26

本文选题：大功率线性压缩机　切入点：动磁式直线振荡电动机　出处：《中国科学院研究生院(上海技术物理研究所)》2016年博士论文　论文类型：学位论文

【摘要】：本文在国家大型巡天相机研制的项目背景下,针对高温区大冷量脉冲管制冷机的性能指标要求,设计开发了一台采用动磁式直线振荡电动机驱动的大功率线性压缩机。全文介绍了线性压缩机研制中所涉及的关键技术,通过理论与实验研究了压缩机样机与一台同轴型脉冲管制冷机的耦合特性。通过解析模型研究了C字形直线振荡电动机的磁路特性。结合电机结构参数,从能量角度给出了电动机电磁力和线圈电感的表达式。利用电磁有限元软件对电动机的静态特性进行了模拟,确定了永磁体、励磁线圈、磁轭等关键部件的最优几何尺寸,并验证了电动机在特定负载下的动态运行特性。通过实验对电动机损失机理进行了研究。建立了线性压缩机的动力学模型,理论分析了压缩活塞的动力特性。讨论了不同阻尼条件下“质量-弹簧-阻尼”系统的振动特性,实验测量了样机机械阻尼系数,研究了谐振状态和非谐振状态下压缩活塞的运动特性。理论研究了材料、型线以及结构尺寸对板弹簧轴向和径向刚度的影响,并借助结构有限元软件对具有偏心圆渐开线型和阿基米德螺旋线型的两种板弹簧轴向和径向刚度、应力分布以及振动模态进行了模拟,通过实验测量了两种板弹簧的轴向刚度,与模拟值误差在2%以内。通过相位关系理论分析了典型斯特林制冷机与脉冲管制冷机的热力学过程,研究了线性压缩机压缩腔内气体力的非线性特征,并通过傅立叶变换将其进行线性近似处理,等效为气体弹簧力和气体阻尼力。类比变压器原理,将线性压缩机与回热式制冷机的匹配看作是“电磁-机械-声”耦合场,通过各阻抗关系,推导了电动机机械效率和压缩机PV功转化效率的阻抗表达式。得到了线性压缩机最大PV功转化效率随阻抗的变化规律。针对线性压缩机与回热式制冷机的耦合特性,对ANSY Maxwell电磁分析软件进行了自定义脚本开发,并搭建了线性压缩机动态运行的联合数值仿真平台。并通过实验验证了数值仿真的准确性和有效性。理论分析了压缩机功率因数的影响因素,提出了提高压缩机功率因数的方法,并通过实验研究了不同充气压力和板弹簧刚度下压缩机的谐振特性。压缩机重8kg,最大输入功率大于500W。实验测得样机静态比推力为13.9N/A,动态平均电感为17.26mH。空载谐振状态下的最优运行频率为30.5Hz。该样机在驱动一台同轴型脉冲管制冷机时,240W输入功率下,获得30W/170K的制冷性能。驱动两台相同的同轴型脉冲管制冷机,405W输入功率下,获得50W/170K的制冷性能,电动机效率和压缩机PV功转化效率分别为76%和45%。压缩机并联无极性电容后,电动机功率因数提高到0.88,电动机效率达到88%。驱动大冷量脉冲管冷指,175W和320W输入功率下,分别能够获得30W/170K和50W/170K的制冷性能,压缩机效率达到83.5%。
[Abstract]:In this paper, under the background of the development of the national large-scale aerial patrol camera, the performance requirements of the pulse tube refrigerator with large cooling capacity in the high temperature region are discussed. A high power linear compressor driven by moving magnetic linear oscillation motor is designed and developed. The key technologies involved in the development of linear compressor are introduced in this paper. The coupling characteristics of the compressor prototype and a coaxial pulse tube refrigerator are studied theoretically and experimentally. The magnetic circuit characteristics of the C-shaped linear oscillation motor are studied by analytical model. The expressions of the electromagnetic force and coil inductance of the motor are given from the angle of energy. The static characteristics of the motor are simulated by using the electromagnetic finite element software, and the optimum geometric dimensions of the key components, such as permanent magnet, excitation coil and yoke, are determined. The dynamic characteristics of the motor under specific load are verified. The mechanism of motor loss is studied through experiments. The dynamic model of linear compressor is established. The dynamic characteristics of compression piston are theoretically analyzed. The vibration characteristics of mass-spring-damping system under different damping conditions are discussed. The mechanical damping coefficient of the prototype is measured experimentally. The motion characteristics of compression piston in resonant and non-resonant states are studied. The effects of material, profile and structure size on the axial and radial stiffness of plate spring are theoretically studied. The axial and radial stiffness, stress distribution and vibration modes of two kinds of plate springs with eccentric involute and Archimedes helix are simulated by means of structural finite element software. The axial stiffness of two kinds of plate springs are measured by experiments. The thermodynamic process of the typical Stirling refrigerator and the pulse tube refrigerator is analyzed by the phase relation theory, and the nonlinear characteristics of the gas force in the compression chamber of the linear compressor are studied. By Fourier transform, the linear approximation is carried out, which is equivalent to the gas spring force and the gas damping force. By analogy with the principle of transformer, the matching between the linear compressor and the regenerative refrigerator is regarded as an electromagnetic mechanical-acoustic coupling field. Through the impedance relations, The impedance expressions of the motor mechanical efficiency and the PV power conversion efficiency of the compressor are derived. The law of the maximum PV power conversion efficiency with the impedance of the linear compressor is obtained. The coupling characteristics between the linear compressor and the regenerative refrigerator are discussed. In this paper, ANSY Maxwell electromagnetic analysis software is developed with custom script. A joint numerical simulation platform for the dynamic operation of linear compressors is built. The accuracy and validity of the numerical simulation are verified by experiments. The influencing factors of compressor power factor are analyzed theoretically. The method of improving the power factor of compressor is put forward. The resonant characteristics of the compressor under different inflatable pressure and plate spring stiffness are studied experimentally. The compressor weighs 8 kg and the maximum input power is greater than 500 W. the static specific thrust of the prototype is 13.9 NPA, and the dynamic average inductance is 17.26 mH. The optimal operating frequency is 30.5 Hz under the condition of driving a coaxial pulse tube refrigerator with an input power of 240W. The refrigeration performance of 30W / 170K is obtained. The refrigeration performance of 50W / 170K is obtained by driving two identical coaxial pulse tube refrigerators with 405W input power. The motor efficiency and the PV power conversion efficiency of the compressor are 76% and 45.After the parallel connection of the compressor without polarity, The motor power factor is increased to 0.88, and the motor efficiency reaches 88. Under the input power of 175W and 320W, the refrigeration performance of 30W / 170K and 50W / 170K can be obtained, respectively, and the compressor efficiency reaches 83.5%.
【学位授予单位】：中国科学院研究生院(上海技术物理研究所)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TB652

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