In High-temperature Solar Thermal Acoustic Device Heat Exchanger Simulation And Optimization

A thermoacoustic engine is of the advantages of high reliability, low noise, simple construction, no moving parts, non-pollution etc .At present, the study of thermoacoutic is one of the most attractive research fields in energy power area.In thermoacoustic system, the oscillating heat transfer in regenerator is along the axis direction of the stack and in heat exchanger it is along the radial direction of the tube. The heat transfer characteristic in thermoacoustic heat exchanger is very complex and has not been completely understood. In general, the design methods of the heat exchangers are not suitable for oscillating flow heat exchangers. An analysis and design tool for heat exchanger of thermoacustic engine is provided in the paper.Based on thermoacoustic basic equations and taking the viscosity of working gas into account, a nondimensional model has been established to study the characteristic of oscillating heat transfer in the thermoacoutic heat exchanger. With numerical method, a collocation model based on radial basis function theory to calculate oscillating temperature distribution in ducts was set up. After the calculation, the radial oscillating temperature distribution in the tube of constant wall temperature can be observed. The optimal nondimensional tube radius r0 ,opt and the dimensionless integral Q were determined by trapezoid formula and the dimensionless integral Q represents the effecting of geometry on the average value of heat transfer rate per unit of duct volume. It was also found that the optimal radius r0 ,opt is relative to changes with the pressure amplitude△Pmax and the length of the heat exchanger L. And from the calculation, the operating conditions, such as pressure amplitude and frequency can affect the performance of the heat exchanger, so an effective analysis tool for studying the performance of heat exchanger in different operating conditions can be obtained.