Self-circulating flow in thermoacoustic heat engines for efficient heat transfer

热声发动机将热能转化为高振幅声波，随后转化为电能。 这种方法的优点之一是，热量在没有运动部件的情况下转化为功，这使得发动机可靠且无需维护。热量可以通过燃烧诸如天然气或生物质的燃料或通过利用废热来提供。该技术具有显著的潜力，通过废热利用移动的、分布式或远程热电联产来提高能源系统效率。*对于涉及废热利用的应用，需要将热源有效地耦合到发动机。使用传统的热交换器，这可能是困难和昂贵的。一种更简单且潜在有效的将热量输送到发动机的方法是在将废热源连接到热声发生器的回路中使用平均流。使用文丘里管结构来驱动回路中的流动已经被证明，但是需要测试、表征和优化以用于商业应用。本计画将以实验与数值分析的方式，探讨文丘利管设计与操作条件对自循环流动回路之热传效能的影响。将确定创建自循环流的首选设计。*

Thermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently into electric power. One of the advantages of this approach is that heat is converted to work with no moving parts which makes the engine reliable and maintenance free. Heat may be provided by combusting fuel such as natural gas or biomass, or by utilizing waste heat. The technology has significant potential for increasing energy system efficiency through waste-heat utilization for mobile, distributed, or remote combined heat and power generation.****For applications involving waste-heat utilization, efficient coupling of the thermal source to the engine is required. This can be difficult and costly using conventional heat exchangers. A simpler, and potentially efficient method to transport heat to the engine is using mean flow in a loop connecting the waste heat source to the thermoacoustic generator. The use of venturi structures to drive flow in a loop has been proven, but requires testing, characterization, and optimization for use in commercial applications. This project will experimentally and numerically analyze the impacts of venturi design and operating conditions of heat transfer effectiveness of a self-circulating flow loop. Preferred designs to create self-circulating flow will be identified.****