Studying On The Mechanism Of Heat Transfer Of Micro Heat Exchangers

With the development of MEMS, the requiring for micro heat exchangers is increasing, so micro heat exchangers became hot research area. This paper is about the research of polymer micro heat exchangers. Based on practical testing, the impact of micro scale and mechanism of heat transfer will be discussed to serve for the optimal structure design. FloEFD software were utilized to design and simulate the polymer micro heat exchangers to get the flow and heat transfer mechanism. It is provided a more practical approach for manufacture and using.The experiment system for polymer micro heat exchangers was designed and be comprised of a work substance fluid circle and an electric control unit. Precision pressure gauge, flow meter and data collection and processing system were used to insure the veracity of the result. The experimental section was divided into three parts which are plastic shells, plastic outlet and inlet ports as well as test piece (micro-channel). In order to know the influence of heat exchange efficiency under different channel shapes, structures and materials, the test piece was designed to be replaceable. As for the shell and especially for the inlet outlet ports, they were manufactured by splitting mould processing instead of the traditional mechanical processing. The testing results show that experiment system can meet the need to evaluate the heat transfer of micro heat exchangers.Using FloEFD software, simulation was done to the heat transfer process of polymer micro heat exchangers. From the cross section, equivalent diameter, porosity, the length-diameter ratio, depth-width ratio these five aspect, flow characteristic curve and heat-transfer characteristic curve can be got to do research on different kinds of micro heat exchangers. These can be used as basis for further experiment and simulation.According to the simulation results, polymer micro heat exchanger was designed using water and air as the cooling substance. Finally the possibility of polymer instead of metal materials was verified and then metal-polymer composites micro heat exchanger was proposed, and the numerical simulation was done to evaluate the heat transfer capacity.The innovation are as follows:(1) The experiment system for polymer micro heat exchangers was designed, the test piece was designed to be replaceable. As for the shell and especially for the inlet outlet ports, they were manufactured by splitting mould processing and the material was PP.(2) The possibility of polymer instead of metal materials to produce high efficiency micro heat exchangers was verified using both the theory and the simulation. Finally we designed and did research on metal-polymer composites micro heat exchangers.