行波型热声发动机的网络模型理论与实验研究

发布时间：2018-07-25 15:42

【摘要】：热声发动机是通过热声效应由热产生机械动力的一种装置。不同于常规的机械式压缩机,它具有无运动部件、结构简单、可靠性高、寿命长等特点;可采用惰性气体作为工质,对环境无污染,环保性能高;可采用低品位热源作为驱动源,能源综合利用性能高。因此,在现代新能源利用技术中,热声发动机具有很大的发展潜力和广泛的应用前景。目前,热声热机的数值计算在热声学的研究进程中越来越受到重视,通过对热声系统模拟可以对系统内的热力学特性进行预测,而且能够为热声系统的实验研究和热声热机的设计提供很大的帮助。普遍认为,行波热声设备的效率要高于驻波设备,因此,对行波型热声热机的研究已成为热声领域的研究热点。本文采用分布参数法并利用传输矩阵方程,计算出行波形热声发动机的谐振频率,得出的振荡频率为复频率形式,其实部代表实际频率,虚部表示压力幅值的衰减程度。并对处于不同结构参数和运行参数情况下的系统频率进行了比较计算,得到了各参数对系统谐振频率的影响规律。把已经计算出的系统频率带入到各传输矩阵方程中,对行波型热声发动机系统内的声场分布特性,包括波动压力振幅、体积流率振幅、压流之间的相位差以及声功流等分布进行了数值模拟,对此类发动机内的声场分布有了更为深入的认识。在数值计算的基础上,结合DeltaEC软件研制并搭建了一台行波型热声发动机,以氮气为工质进行了初步实验研究。得出在相同的加热功率下,随着工作压力的增大,加热温度逐渐降低。当压力一定时,随着加热功率的增加,加热温度也呈上升趋势,系统拥有的压比也更大,压比越大意味着热声系统的做功能力越强。因此,可以通过调节加热功率来控制系统的温度,进而提高系统的压比和热声转化效率。
[Abstract]:A thermoacoustic engine is a device that generates mechanical power from heat through thermoacoustic effects. Different from the conventional mechanical compressor, it has no moving parts, simple structure, high reliability, long life and so on. It can use inert gas as working fluid, no pollution to the environment and high environmental protection performance. The low grade heat source can be used as the driving source and the comprehensive utilization performance of energy is high. Therefore, thermoacoustic engine has great development potential and wide application prospect in modern new energy utilization technology. At present, more and more attention has been paid to the numerical calculation of thermoacoustic engine in the research process of thermoacoustics. The thermodynamic characteristics of the thermoacoustic system can be predicted by simulating the thermoacoustic system. And it can provide great help for the experimental research of thermoacoustic system and the design of thermoacoustic engine. It is generally believed that the efficiency of traveling wave thermoacoustic equipment is higher than that of standing wave equipment. Therefore, the research on traveling wave thermoacoustic machine has become a hot spot in the field of thermoacoustic. In this paper, the resonant frequency of the trip waveform thermoacoustic engine is calculated by using the distribution parameter method and the transfer matrix equation. The oscillation frequency is in the form of complex frequency, in fact, the part represents the actual frequency, and the imaginary part represents the attenuation degree of the pressure amplitude. The frequency of the system with different structure parameters and operation parameters is compared and calculated, and the influence of each parameter on the resonant frequency of the system is obtained. The calculated system frequency is introduced into each transmission matrix equation, and the acoustic field distribution characteristics in the traveling wave thermoacoustic engine system, including the amplitude of wave pressure, the amplitude of volume flow rate, the distribution of sound field in the traveling wave thermoacoustic engine system are studied. The phase difference between pressure flow and the distribution of acoustic work flow are numerically simulated, and the distribution of sound field in this kind of engine is more deeply understood. On the basis of numerical calculation, a traveling wave thermoacoustic engine was developed and built with DeltaEC software. Under the same heating power, the heating temperature decreases with the increase of working pressure. When the pressure is constant, the heating temperature increases with the increase of heating power, and the pressure ratio of the system is larger. The higher the pressure ratio is, the stronger the work ability of thermoacoustic system is. Therefore, the temperature of the system can be controlled by adjusting the heating power, and the pressure ratio and thermoacoustic conversion efficiency of the system can be improved.
【学位授予单位】：辽宁科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK401

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