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Synthetical optimization of the structure dimension for the thermoacoustic regenerator

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Chinese Physics B 2022年第3期31卷 323-328页

作者：康慧芳张凌霄沈俊丁夏琛李振兴刘俊 Beijing Institute of Technology Beijing 100124China Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100190China

The quantitative investigation of parameters in the renegerator is essential for the optimization of thermoacoustic devices, while the majority of the previous research only considered parameters of the working field, working gas and the hydraulic radius. Based on the linear thermoacoustic theory, this paper extracts a normalized parameter for low-amplitude conditions, which is called the regenerator operation factor. By extracting the regenerator operation factor and relative hydraulic radius, the influence of frequency on the efficiency can be controlled and offset. It can be found that thermoacoustic devices with different frequencies can perform the same efficiency by adjusting the radius in proportion to the axial length.Finally, this paper synthetically optimizes the dimension of the thermoacoustic regenerator by taking the regenerator operation factor, relative hydraulic radius and acoustic field parameter as variables. Conclusions in this paper are of great significance for explaining the best working conditions of engines and directing the miniaturization and optimal design of thermoacoustic devices.

关键词： thermoacoustic regenerator hydraulic radius regenerator length

A looped heat-driven thermoacoustic refrigeration system with direct-coupling configuration for room temperature cooling

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Science Bulletin 2019年第1期64卷 8-10页

作者： Huizhi Wang Limin Zhang Guoyao Yu Jianying Hu Ercang Luo Ying Ma Chao Jiang Xianxian Liu Key Laboratory of Cryogenics Technical Institute of Physics and Chemistry Chinese Academy of Sciences School of Engineering Science University of Chinese Academy of Sciences School of Future Technology University of Chinese Academy of Sciences

Heat-driven thermoacoustic refrigeration has drawn extensive concern in the past decades due to its advantages of high reliability and external heat-driven mechanism.In such a system,heat can be firstly converted into acoustic power and then the acoustical power drives a refrigerator to generate cooling effect without any moving mechanical components.So far,most of researches on heat-driven thermoacoustic refrigeration have focused on cryo- genic application,such as natural gas liquefaction [1,2].In addition, heat-driven thermoacoustic refrigeration also plays important roles in recovering waste heat and provides an environment- friendly alternative to the current abso'rption chiller especially in the small-scale power range [3-7].However,two main obstacles to use the thermoacoustic technology in practice are its relatively low cooling capacity and low cooling efficiency.Either the two-loop configuration proposed by Luo et al.[5]or the configuration of a one-unit refrigerator driven by a three-unit engine brought forward by Kees [6],they both suffer from phase-shifting tube and mismatch between the thermoacoustic engine (TAE)and thermoacoustic refrigerator (TAR).

关键词： Direct coupling Refrigeration system thermoacoustic refrigeration driven by heat

Thermodynamic analysis of onset characteristics in a miniature thermoacoustic Stirling engine

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Journal of Thermal Science 2013年第3期22卷 216-222页

作者： Xin HUANG Gang ZHOU Qing LI Key laboratory of Cryogenics Technical Institute of Physics and Chemistry Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences

This paper analyzes the onset characteristics of a miniature thermoacoustic Stirling heat engine using the ther-modynamic analysis method. The governing equations of components are reduced from the basic thermodynamic relations and the linear thermoacoustic theory. By solving the governing equation group numerically, the oscillation frequencies and onset temperatures are obtained. The dependences of the kinds of working gas, the length of resonator tube, the diameter of resonator tube, on the oscillation frequency are calculated. Meanwhile, the influences of hydraulic radius and mean pressure on the onset temperature for different working gas are also presented. The calculation results indicate that there exists an optimal dimensionless hydraulic radius to obtain the lowest onset temperature, whose value lies in the range of 0.30 0.35 for different working gases. Furthermore, the amplitude and phase relationship of pressures and volume flows are analyzed in the time-domain. Some experiments have been performed to validate the calculations. The calculation results agree well with the experimental values. Finally, an error analysis is made, giving the reasons that cause the errors of theoretical calculations.

关键词： Stirling thermoacoustic engine high frequency thermodynamic onset temperature

In vivo tumor detection with com bined MR-Photoacoustic-thermoacoustic imaging

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Journal of Innovative Optical Health Sciences 2016年第5期9卷 38-47页

作者： Lin Huang Wei Cai Yuan Zhao Dan Wu Lei Wang Yuqing Wang Dakun Lai Jian Rong Fabao Gao Huabei Jiang School of Physical Electronics University of Electronic Science and Technology of China Chengdu 610054 P.R.China Department of Biomedical Engineering University of Florida FL 32611USA Department of Radiology West China Hospital Sichuan UniversityChengduSichuan 610041P.R.China

Here,we report a new method using combined magnetic resonance(MR)-Photoacoustic(PA)-thermoacoustic(TA)imaging techmiques,and demonstrate its unique ability for in vrivo cancer detection using tumor-bearing mice.Circular scanning TA and PA imaging systems were used to recover the dielectric and optical property dist ributions of three colon carcinoma bearing mice While a 7.0-T magnetic resonance imaging(MRI)unit with a mouse body volume coil was utilized for high resolution structural imaging of the same mice.Three plastic tubes flled with soybean sauce were used as fiducial markers for the co-registration of MR,PA and TA images.The resulting fused images provided both enhanced tumor margin and contrast relative to the surrounding normal tissues.In particular,some finger-like protrusions extending into the surrounding tissues were revealed in the MR/TA infused images.These results show that the tissue functional optical and dielectric properties provided by PA and TA images along with the anatomical structure by MRI in one picture make accurate tumor identification easier.This combined MR-PA-TA-imaging strategy has the potential to offer a dinically useful triple-modality tool for accurate cancer detection and for intraoper ative surgical navigation.

关键词： thermoacoustic photoacoustic MRI in vivo tumor detection

Characterising thermoacoustic emission in alternating current spot welding process

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China Welding 2013年第3期22卷 66-72页

作者：李立峰罗震凡乃峰任吉刚李洋料 School of Materials Science and Engineering Tianjin University Tianjin 300072

The acoustic emission of spot welding with thermoacoustic theory was studied in this paper, which provides new basis to analyze the quality of nugget with acoustic signal. The result shows that the thermoacoustic emission exists in both 5052 Al alloy and cold-rolled steel AC spot welding process and this process takes place later than the load of welding current, and the frequency of thermoacoustic is twice as that of the welding current. The amplitudes of thermoacoustic signals detected from different angles are different, which undergo an up-down-up process. The thermoacoustic emission shows different trends with the thickness increase in AC resistance spot welding experiment for 5052 Al alloy and cold-rolled steel.

关键词： spot welding thermoacoustic welding current nugget amplitude

Investigation on porous frequency of regenerator of microminiature thermoacoustic refrigerator

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Journal of Central South University of Technology 2005年第Z1期12卷 253-255页

作者： LIU Yi-cai ZHOU Jie-min ZHOU Nai-jun LIAO Sheng-ming School of Energy and Power Engineering Central South University Changsha 410083 China School of Energy and Power Engineering Central South University Changsha 410083 China School of Energy and Power Engineering Central South University Changsha 410083 China School of Energy and Power Engineering Central South University Changsha 410083 China

A new method was proposed to directly measure the effective resistance and distinguish the porous frequency in the regenerator of the microminiature thermoacoustic refrigerator. Measured results were compared with the flux gain factor and transmission loss of the real system. The results show that the agreement between the range of the porous frequency and frequency of the system is good, the method can be used to predict the porous frequency of the regenerator in production.

关键词： porous frequency microminiature thermoacoustic regenerator

Measuring Sound Pressure Levels during thermoacoustic Instabilities in Large Engines: Case Study

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Journal of Modern Physics 2017年第10期8卷 1685-1699页

作者： Alice Elizabeth González José Cataldo Ottieri Pablo Gianoli Kovar Joaquín Montero Croucciée Marcos Raúl Lisboa Department of Environmental Engineering IMFIA—Faculty of Engineering Universidad de la República Montevideo Uruguay

This paper attempts to present some registers of sound pressure levels during the operation of large diesel engines (10 MW). During these registers we have found the preparation, occurrence and ending of events of thermoacoustic instability. They appear after a loosing of chaos period or a reduction in fluctuations in some frequencies. The most interesting phenomena were registered at low frequencies. However, they were accompanied by variations in sound emissions at medium and high frequencies. As there has been very little published data concerning these phenomena at real scale, it is imperative to point out that every quasi-stationary state we have measured during these episodes has lasted some minutes, significantly much more time than that of lab scale results.

关键词： thermoacoustic Instabilities Large Engines Real Scale Measurements

Development and Assessment of thermoacoustic Generators Operating by Waste Heat from Cooking Stove

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Engineering（科研） 2012年第12期4卷 894-902页

作者： Baiman Chen Abdalla A. Yousif Paul H. Riley David B. Hann Department of Mechanical Materials and Manufacturing Engineering The University of Nottingham in Malaysia Department of Mechanical Materials and Manufacturing Engineering The University of Nottingham in Malaysia Semenyih Malaysia Faculty of Engineering The University of Nottingham Nottingham UK

This paper presents the development and assessment of two low-cost, travelling wave, thermoacoustic generators operating by waste heat energy from cooking stove. One powered by waste heat from a propane-driven stove, the other powered by waste heat from a wood-burning stove. The propane-driven thermoacoustic generator was successfully demonstrated to produce approximately 15 watts of electricity using a commercial audio loudspeaker. The wood-burning thermoacoustic generator was successfully constructed and tested to generate a maximum of 22.7 watts of electricity under a pressurised condition. The latter has a high potential to be used by over 1.5 billion people in rural communities for applications such as LED lighting, charging mobile phones or charging a 12V battery. A comprehensive power assessment of the propane-driving generator as well as the development and performance assessment of the wood-burning generator are described throughout this article.

关键词： Cooking Stove Electricity thermoacoustic Engine Waste Heat

Extension of the pressure correction method to zero-Mach number compressible flows

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Science China(Technological Sciences) 2009年第6期52卷 1583-1595页

作者： HE YaLing HUANG Jing TAO YuBing TAO WenQuan State Key Laboratory of Multiphase Flow in Power Engineering School of Energy&Power EngineeringXi’an Jiaotong UniversityXi’an 710049China

In the present paper,the classical pressure correction method was extended into low Mach number compressible flow regime by integrating equation of state into SIMPLE algorithm.The self-developed code based on this algorithm was applied to predicting the lid-driven cavity flow and shock tube prob-lems,and the results showed good agreement with benchmark solutions and the Mach number can reach the magnitude of as low as 10-5.The attenuation of sound waves in viscous medium was then simulated.The results agree well with the analytical solutions given by theoretical acoustics.This demonstrated that the present method could also be implemented in acoustics field simulation,which is crucial for thermoacoustic simulation.

关键词： thermoacoustic engine pressure correction method low Mach number compressible flow