Investigation of the mechanism of the reduction of the critical temperature difference of thermoacoustic engines having a wet regenerator

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K17705
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: General applied physics; Energy engineering
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Ueda Yuki 東京農工大学, 工学(系)研究科(研究院), 教授 (00447509)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 熱音響エンジン / 低温排熱

Outline of Final Research Achievements

In this study, thermoacoustic phenomena coupled with evaporation and condensation of water was investigated. First, we constructed a thermoacoustic engine that was composed of a wide-long tube and narrow-short tubes. The diameter and length of the wide-long tube were 40 mm and 2 m, respectively, whereas those of narrow-short tubes were 0.8 mm and 40 mm, respectively. The engine worked when the temperature difference between the sides of the stack was above the critical value. We compared the critical temperature difference in two conditions. One condition was that the stack wall had liquid water and the other was that it had no liquid water. It was turned out that the critical temperature difference with water is much smaller than that without water. Next, we were successful in numerically reproducing this experimental results by using the theory that can treat the acoustic wave propagation in a wet-wall tube.

Free Research Field

熱音響工学

Academic Significance and Societal Importance of the Research Achievements

本研究では熱音響エンジンの稼働温度が液体の水の存在により低下する現象について，そのメカニズムを実験および数値計算により解析した．熱音響エンジンはピストンやバルブなどの可動部品を一切持たない，外燃機関であるため，長寿命，低メンテナンスコストを実現できる排熱利用エンジンとしての応用が期待されている．本研究により，水の存在により稼働温度が100℃以下にできることが明らかになり，特に低温排熱の利用可能性が示された．また，数値計算による再現にも成功しており，装置の設計指針やその効率の予測も可能になった．