Temperature Difference and Stack Plate Spacing Effects on Thermodynamic Performances of Standing-Wave Thermoacoustic Engines Driven by Cryogenic Liquids and Waste Heat  

作　　者：GUO Lixian ZHAO Dan BECKER Sid 

机构地区：[1]Department of Mechanical Engineering,College of Engineering,University of Canterbury,Private Bag 4800,Christchurch,8041,New Zealand

出　　处：《Journal of Thermal Science》2022年第5期1434-1451,共18页热科学学报（英文版）

基　　金：the financial support (452DISDZ) from University of Canterbury, New Zealand;University of Canterbury for providing PhD scholarship。

摘　　要：The standing-wave thermoacoustic engines(TAE)are applied in practice to convert thermal power into acoustic one to generate electricity or to drive cooling devices.Although there is a number of existing numerical researches that provides a design tool for predicting standing-wave TAE performances,few existing works that compare TAE driven by cryogenic liquids and waste heat,and optimize its performance by varying the stack plate spacing.This present work is primarily concerned with the numerical investigation of the performance of TAEs driven by cryogenic liquids and waste heat.For this,three-dimensional(3-D)standing-wave TAE models are developed.Mesh-and time-independence studies are conducted first.Model validations are then performed by comparing with the numerical results available in the literature.The validated model is then applied to simulate the standing-wave TAEs driven by the cryogenic liquids and the waste heat,as the temperature gradientΔT is varied.It is found that limit cycle oscillations in both systems are successfully generated and the oscillations amplitude is increased with increasedΔT.Nonlinearity is identified with acoustic streaming and the flow reversal occurring through the stack.Comparison studied are then conducted between the cryogenic liquid-driven TAE and that driven by waste heat in the presence of the same temperature gradientΔT.It is shown that the limit cycle frequency of the cryogenic liquid system is 4.72%smaller and the critical temperatureΔT_(cri)=131 K is lower than that of the waste heat system(ΔT_(cri)=187 K).Furthermore,the acoustic power is increased by 31%and the energy conversion efficiency is found to increase by 0.42%.Finally,optimization studies on the stack plate spacing are conducted in TAE system driven by cryogenic liquids.It is found that the limit cycle oscillation frequency is increased with the decreased ratio between the stack plate spacing and the heat penetration depth.When the ratio is set to between 2 and 3,the overall performance of the cryogenic

关 键 词：thermoacoustic engine STANDING-WAVE CRYOGENIC THERMODYNAMICS acoustical energy plate spacing heat transfer acoustic streaming 

分 类 号：TK401[动力工程及工程热物理—动力机械及工程]