Research and Development on Improving Heat Dissipation Efficiency of Heat Piles by Use of a Thermoacoustic Effect

• Main Authors: Chung-Han Chiou, 邱崇瀚
• Other Authors: 李世光
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/90309589982664275204

碩士 === 臺灣大學 === 工程科學及海洋工程學研究所 === 95 === Thermoacoustic effect has already been discovered by glassmakers for more than 200 years. Through many scholars’ research effort, detailed qualitative analysis of thermoacoustic effect has been developed over the years. The theory of thermoacoustic and its mathematic model were developed by integrating thermodynamics, fluid mechanics, heat transfer, and acoustics. As implied by the name, thermoacoustic effect is the transformation between heat energy and acoustical energy. Thermoacoustic heat engine can generate acoustic standing waves and acoustic streaming by a temperature difference located between heated side and cool side of a stack in a resonance tube. On the contrary, acoustic standing waves in a resonance tube can generate a temperature difference between heated side and cool side of stack. While thermoacoustic refrigerant was well developed, thermoacoustic heat engine remains within the development stage. This thesis discusses the thoughts behind the intention to integrate thermodynamics, fluid mechanics, heat transfer, acoustics, and thermoacoustics to examine cooling efficiency improvement in heat piles. In addition, it transforms thermoacoustic heat engine system to thermoacoustic cooling system. Utilizing the theory of thermoacoustic and experimental investigation, it identifies a hysteretic loop of onset and termination of thermoacoustic effect and it concludes by identifying some factors which may influence the behaviors of thermoacoustic effect. These newly identified factors include critical temperature difference, length of the resonance tube, working fluid and stack’s material, thickness, and porosity. By means of these factors, it tries to optimize the design of thermoacoustic cooling system.