A Study On The Characteristics Of Miniature Thermoacoustic Refrigerator And The Key Components

A miniature thermoacoustic refrigerator occupies many special advantages such as simplicity, reliability, no pollution, readily adaptable to microcircuit interfacing, which attracts great interest in the use of heat management. However, there are many challenges in the engineering application research of the miniature thermoacoustic refrigerator which come along with the frequency rising and dimension decreasing, for example, the increasing of viscosity losses and lacking of suitable high sound pressure driver. Therefore, this thesis investigates the theory and experiment of the miniature thermoacoustic refrigerator. Based on the linear thermoacoustic theory and thermodynamic network model, this thesis develops a computation software for the designing and optimization of miniature thermoacoustic refrigerator. On the basis of the calculation and analytic results, a miniature thermoacoustic refrigerator has been built. In this thesis, progresses are made as follows:First of all, in order to get a compromise between the calculation speed and precision, this thesis developed a new computation software to design the thermoacoustic refrigerator, especially the core part parallel stack. Based on the calculation, an optimization operation and structural parameters are acquired.Then the vibration model of piezoelectric loudspeaker is built, in order to get the displacement amplitude and resonant frequency of piezoelectric element, the finite element analysis software Ansys is used. According to the test results of piezoelectric loudspeaker's impedance and resonator frequency, a suitable acoustic driver is built. Based on the detail design of the cooler part of miniature thermoacoustic refrigerator, a experimental prototype is established.And then, the distribution of oscillation pressure and flow rate in the resonator cavity is analyzed by using of the simulation software Fluent. The analytic result shows that Fluent is feasibility to simulate the problems of thermoacoustic and how to install the solving parameters reasonably. In order to get an optimal resonator structure, several different kinds of structures are tried. According to the calculating results, some numerical analyses are carried out on the experimental prototype using software Fluent, including the distributions and oscillations of pressure and temperature in the system and the regenerator, as well as the influence of the clearances between heat exchangers and regenerator. These can guide the design of refrigerator.Finally, based on the test distributing-point of temperature and pressure, a suit of experiment platform is established.