DESIGN OF A STANDING-WAVE THERMOACOUSTIC ENGINE
DESIGN OF A STANDING-WAVE THERMOACOUSTIC ENGINE
复制标题
驻波热声发动机的设计
DOI：
--
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
C. Lawn
中科院分区：
文献类型：
--
作者：
C. Gardner;C. Lawn
该项目名为“烹饪，制冷和电力炉灶”，其雄心勃勃的目标是根据热声原理制造一台150 W的发电机，该发电机由燃烧木材的炉灶的热量驱动。由于线性交流发电机仅包括运动部件，因此预期该装置最终应以非常低的成本生产，以在欠发达国家中广泛部署。第一个概念是探讨简单的理由是所谓的“驻波”设计，其中只有一小部分的声压是同相的声速。该发动机由一个封闭的线性管道组成，该管道包含一个连接到热源的高温热交换器和一个将热量排出到周围环境的低温热交换器，它们之间有一个狭窄通道的“堆栈”，以及管道低温端的线性交流发电机。高温热交换器的概念是从火中的陶瓷灯泡到横跨管道的许多金属板的辐射传递，并从那里进入自激声波。热声守恒方程与描述辐射热交换的方程一起求解，以确定该概念在所选频率下入射到匹配的交流发电机上的声功率方面的整体性能。进行了敏感性研究，以检查平均压力和管道中的气体成分的影响，以及在堆栈中的通道的长度和直径。最后，决定交流发电机不能匹配所涉及的高声压（>100 mbar），并将注意力转向“行波”设备。
The project entitled ‘Stove for Cooking, Refrigeration and Electricity’ has the ambitious objective of making a 150 W electricity generator based on thermoacoustic principles that is driven by the heat of a wood-burning stove. With a linear alternator involving the only moving part, it is intended that the device should eventually be produced at very low cost for widespread deployment in under-developed countries. The first concept to be explored on the grounds of simplicity was the so-called ‘standing-wave’ design in which only a small fraction of the acoustic pressure is in-phase with the acoustic velocity. The engine consisted of a closed linear duct containing a high-temperature heat exchanger connected to the heat source and a low-temperature heat exchanger rejecting heat to the surroundings, with a ‘stack’ of narrow channels between them, and a linear alternator at the low-temperature end of the duct. The high-temperature heat exchanger concept was one of radiative transfer from a ceramic bulb in the fire to a number of metal plates spanning the duct, and thence into the self-excited acoustic waves. The conservation equations of thermoacoustics were solved together with equations describing the radiative heat exchange, in order to determine the overall performance of this concept in terms of the acoustic power that would be incident on a matched alternator at the chosen frequency. Sensitivity studies were undertaken to examine the influence of the mean pressure and of the composition of gas in the duct, and of the length and diameter of the passages in the stack. Ultimately it was decided that the alternator could not be matched to the high acoustic pressures involved (>100 mbar) and attention was switched to a ‘travelling-wave’ device.