不同结构回热器频率及输出特性研究

发布时间：2018-04-28 10:20

本文选题：热声网络 + 回热器　；参考：《中南大学》2014年硕士论文

【摘要】：回热器是热声转换的核心部件,其结构影响着热声系统的起振温度、压力波动、运行频率等工作特性。目前,现有的回热器的结构较为单一,且鲜有针对回热器输出特性的研究。本文在国家自然科学基金项目(51276201)和前人工作的基础上,提出了两种新型回热器并研究了频率特性及输出特性。本文依据流体阻抗法,推导热声系统频率方程,计算出系统的前七阶频率值。利用DeltaEC软件设计了1/4波长驻波型热声发动机,计算出模型的压力分布及体积流率分布。实验研究了不同热端加热功率下,采用蜂窝陶瓷回热器的热声热机系统的起振温度、工作频率、压力振幅等基本工作特性。结果表明：1.系统起振温度随加热功率增加而降低。2.加热功率为98W、115W时整个起振过程中,热端温度上升较稳定；加热功率133W时,热端温度出现了剧烈的波动,且加热功率越大,热声系统压力振幅越高,相应消振时间越长。3.实验结果与计算频率相符,研究得出系统运行频率与加热功率无关。采用翅片式回热器与蜂窝陶瓷回热器的热声特性相比较,当热端加热功率133W时,翅片式回热器起振温度略低；压力振幅远小于蜂窝陶瓷回热器稳定工作时的压力振幅,消振时压力波动瞬间下降；两者运行频率也不相同。本文创新设计了卷筒丝网回热器,实验数据表明,系统起振温度较高；起振过程稳定；系统运行频率与蜂窝陶瓷回热器运行频率相同。最后,采用压电陶瓷发电片研究了热声热机采用蜂窝陶瓷回热器、翅片式回热器时的系统输出特性,测得输出电压波动以压电片的振荡频率。
[Abstract]:Regenerator is the core component of thermoacoustic conversion. Its structure affects the working characteristics of thermoacoustic system, such as temperature, pressure fluctuation, operating frequency and so on. At present, the current structure of the regenerator is relatively simple, and there are few studies on the output characteristics of the regenerator. Based on the project of National Natural Science Foundation 51276201) and previous works, two new regenerators are proposed and the frequency and output characteristics are studied. Based on the fluid impedance method, the frequency equation of thermoacoustic system is derived, and the first seven order frequency values of the system are calculated. A 1 / 4 wavelength standing wave thermoacoustic engine was designed by using DeltaEC software. The pressure distribution and volume flow rate distribution of the model were calculated. The starting temperature, working frequency and pressure amplitude of the thermoacoustic thermo-mechanical system with honeycomb ceramic regenerator under different hot end heating power are studied experimentally. The result shows that 1: 1. The starting temperature of the system decreases with the increase of heating power. When the heating power is 98 W / 115W, the temperature of the hot end increases steadily, and the temperature of the hot end fluctuates sharply when the heating power is 133W, and the higher the heating power is, the higher the pressure amplitude of the thermoacoustic system is and the longer the damping time is. 3. The experimental results are consistent with the calculated frequency, and it is found that the operating frequency of the system is independent of the heating power. Compared with honeycomb ceramic recuperator, when heating power at hot end is 133W, the starting temperature of fin regenerator is slightly lower, and the pressure amplitude is much smaller than that of honeycomb ceramic regenerator when it is working stably. The fluctuation of pressure decreases in an instant, and the frequency of operation is not the same. In this paper, the reel screen regenerator is innovatively designed. The experimental data show that the system has a higher starting temperature, a stable starting process and the same operating frequency as the honeycomb ceramic regenerator. Finally, the output characteristics of the thermoacoustic thermoelectric machine with honeycomb ceramic regenerator and wing plate regenerator are studied by using piezoelectric ceramic generator. The oscillation frequency of the piezoelectric plate is measured as the fluctuation of the output voltage.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB657

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