Numerical Simulation Study Of Thermoacoustic Refrigerator Cooling Mechanism

Thermoacoustic refrigerator is a new type of refrigeration equipment which is drivedby sound. It relys on thermoacoustic effect generated in the resonance tube to work. In thispaper,used numerical simulation method to study the whole process of the refrigerationand carried out a detailed analysis of the internal mechanism of action.Firstly,this paper introduces the study background and the imprortance ofthermoacoustic refrigerator,reviewed the development process and research status of thethermoacoustic refrigerator and showed the process of thermoacoustic effect from theperspective of micro-thermodynamic. At the same time discussed the basic theory ofthermoacoustic effects related to fluid mechanics and heat transfer. Described the designstandards of the thermoacoustic refrigerator parts and provides a basis for designimprovements.Secondly, focus on numerical simulation of thermoacoustic refrigeration process, theoccurrence and development mechanism of the thermoacoustic effect was simulated usingCFD numerical calculation method. Firstly,three-dimensional model of resonance tubewas established in ANSYS, modal analysis was carried out and finded the resonantfrequency and this frequency was used as the excitation frequency of the driving source. InCFD, a two-dimensional straight resonance tube model was established, the changes ofspeed, pressure and temperature in the tube were studied when a plate stack was placed,the effects of pressure amplitude on temperature was analyzed. The results show that thetemperature of the media in the resonance tube has a certain degree of volatility, reflectingthe influence of pressure fluctuations in temperature and other parameters. Proves thatimproving the driving pressure amplitude can improve the refrigeration efficiency. Inaddition, the hot and cold side of the stack formed temperature gradient, verified themechanism of thermoacoustic effect.Finally, the refrigeration machine structure was improved based on straight resonancetube simulation. The focus is on internal increase of hot and cold side heat exchanger. Theheat exchanger is an important component of the thermoacoustic refrigerator parts, it playsan important role on thermoacoustic efficiency. Through the coupling calculation method,the whole model was simulated, the internal flow field was analyzed, refrigerator obtainedsome temperature drop, refrigeration effeciency was good, the temperature in the tube waslower than the temperature without heat exchanger and the temperature drop is obvious.Through the research, the mechanism of the thermoacoustic effect is analyzed, obtainsan ideal refrigeration temperature,gets the expected results and confirms thethermoacoustic effect. At the same time, illustrates the feasibility of using fluid analysissoftware on research and brings a shortcut for achieving size miniaturization, theimprovement and optimization of the structure of thermoacoustic refrigerator.