【作者】 谭永翔；

【导师】 邱利民；

【作者基本信息】 浙江大学 ， 制冷与低温工程， 2006， 硕士

【摘要】 热声发动机利用热声效应，实现热能到声功的转换，以压力波动的形式产出机械功。它与常规机械式压缩机最大的不同在于没有机械运动部件，具有结构简单、运行可靠、工作时间长等优点。因此，热声发动机是极具发展前途的新型热机。 本文回顾了热声发展的历史，介绍了线性热声理论，重点论述了热声中的直流现象，包括：直流的产生机理，直流的种类，直流的抑制手段，直流的积极利用。 直流问题是本文的重点。具有环路的斯特林热声发动机引入了反馈回路，实现了行波相位的热声转换，获得了较高的热声转换效率。然而，环路的拓扑结构使得声场中直流的产生成为可能。直流的出现将严重制约了热声发动机的性能。本文以温度和压力测量作为重要实验手段，研究了直流与热声发动机温度分布之间的关系，直流与压比、热声转化效率、声功输出性能之间的关系。指出有效抑制直流能大幅度提高热声发动机的压比和声功输出，加热温度514℃时无负载压比高达1.206，加热功率2700W时最大输出声功约200W，声功输出能力提高近100％，(?)效率提升近90％。基于焓流理论，对直流的强度进行定量分析。本工作对于斯特林热声发动机中直流的深入研究具有重要指导意义。 热声发动机作为声功输出装置，必须为用户输出声功，才真正具有实用意义。因此，本文在理解直流的基础上，还研究了斯特林热声发动机声功输出特性，考察了不同负载、声功传输装置、声功输出口的改变对热声发动机声功输出的影响，以更全面地揭示热声发动机性能。更多还原

【Abstract】 Thermoacoustic engines convert heat into mechanical work in the form of pressure oscillation. With no moving parts, it has the merit of simple configuration and long-life stabilization, which makes it promising and distinct from traditional compressors or heat engines.The history of thermoacoustics is reviewed, followed by brief introduction of theory of linear thermoacoustics. Streaming in thermoacoustics is mainly discussed, in terms of causation, category, suppression methods and deliberate uses.This thesis is primarily concerned with streaming in Stirling thermoacoustic engine. By introducing feedback path, Stirling thermoacoustic engine with toroidal configuration achieves relatively high efficiency in thermoacoustic conversion. However, the toroidal topology allows streaming acoustically induced, which can seriously degrade the performance of the engine. Based on measurements of pressure oscillation and temperature distribution, the relations among streaming, temperature distributions, pressure ratio, thermoacoustic conversion efficiency and acoustic work of the engine were investigated. It is shown that pressure ratio and acoustic work output were remarkably increased by sufficient suppression of streaming. With no acoustic load, the pressure ratio increased to 1.2, when the hot heat exchanger was heated at 517 ℃. When the input of heating power was 2700 W, the maximum output of acoustic power reached nearly 200 W, approximately 100% of rise, corresponding to proximately 90% of rise in exergy efficiency. Besides, a simplified enthalpy model was established in order to quantify the strength of streaming. The investigations are of importance for further understanding streaming in Stirling thermoacoustic engines.Because a thermoacoustic engine functions as an acoustic work generator, its acoustic work output is of most interest. Based on well understanding of streaming, this thesis studied acoustic work production of the engine. The variations of acoustic work output due to different acoustic loads, new acoustic transmission devices and更多还原