01.2020.91.99

CHANGING THE HEAT FLOW IN THE STACK OF LOOP-TUBE TYPE THERMOACOUSTIC SYSTEM USING A HEAT PHASE ADJUSTER

Author(s):
K. Shiraki†*, S. Sakamoto‡, Y Kurata† & Y. Watanabe††

Affiliation(s):
†Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan

‡Department of Electronic Systems Engineering, University of Shiga Prefecture, Hikone, Shiga 522-8533, Japan

††Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan

*Corresponding Author Email: ctwc0360@mail4.doshisha.ac.jp

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

A method to improve the energy conversion efficiency of the loop-tube type thermoacoustic system is proposed. Acoustic boundary conditions are introduced by the local thermal input to a heat phase adjuster (HPA). In the previous study, controlling the sound field by HPA, the sound intensity was increased. In this study, the change of the heat flow in the stack using HPA is focused for clarifying the mechanism to improve the efficiency. In the experiment, the sound pressure in the tube and the temperature of the stack are measured while changing the thermal input to HPA. The sound fields in the tube are evaluated with the transfer matrix method based on the Rott equation considering temperature gradient. In various conditions of HPA, the increasing amounts of the sound intensity and heat flow in the stack are calculated using the sound pressure in the stack. As the result, it is revealed that the heat flow in the stack increases with the thermal input to HPA. It is also demonstrated that HPA has the effects of increasing the heat flow in the stack. Therefore, it is suggested that the factor of improving efficiency due to HPA is increased by the heat flow.