The Research On The Design Method Of Micro Heat Exchanger Based On Thermal Fluid-Structure Interaction

The finite element numerical simulation of heat transfer and structural thermal stress is faced with the restrictions of too many finite elements induced insufficient computing power in which a whole microchannel heat exchanger is taken as object of study, so that the micro-channel heat exchanger structural stress simulation technology is still an engineering challenge. In response to this technical problem, The simplified finite element simulation method was presented in this paper in which symmetrical element displacement boundary is applied by an equivalent elastic support constraints in order to reflect the microchannel wall displacement constraints of heating expansion and cooling contraction. The simplified finite element simulation method achieved a fast simulation of microchannel heat exchanger heat transfer and structural thermal stress, and laid the foundation for micro channel heat exchanger virtual prototype computer-aided engineering design. The flow resistance characteristics, heat transfer characteristics and structural strength properties of different micro channel heat exchanger were studied, which provides a theoretical guidance to the development of high efficiency micro channel heat exchanger. The major achievements are as follows:The cutting symmetry element method in microchannel heat exchanger can not be directly used for simulation of the microchannel heat exchanger structural thermal stress, The finite element numerical simulation of heat transfer and structural thermal stress is faced with the restrictions of too many finite elements induced insufficient computing power in which a whole microchannel heat exchanger is taken as object of study, so that the micro-channel heat exchanger structural stress simulation technology is still an engineering challenge. The symmetry element based simplifies finite element simulation technique of a microchannel heat exchange structural stresses is key technology to solve this difficult problemIn response to this technical problem, The simplified finite element simulation method of microchannel heat exchanger danger zone thermal fluid-solid coupling thermal stress was first presented in this paper in which symmetrical element displacement boundary is applied by an equivalent elastic support constraints in order to reflect the microchannel wall displacement constraints of heating expansion and cooling contraction.Based on the symmetrical element based simplified finite element simulation method, the flow resistance characteristics, heat transfer characteristics and structural strength properties of different micro channel heat exchanger were systematically studied, the research results show the descending order of micro channel heat exchanger flow resistance is triangular microchannel? hexagon microchannel ?rectangular microchannel? oval microchannel ?Circular microchannel, The descending order of actual heated effect of the cold fluid is triangular microchannel?rectangular microchannel ?hexagon microchannel ? oval microchannel ?Circular microchannel, the descending order of heat transfer speed is oval microchannel?Circular microchannel ?hexagon microchannel?rectangular microchannel?triangular microchannel, the descending order of structural strength is triangular microchannel?rectangular microchannel ?hexagon microchannel ?Circular microchannel ? oval microchannel.