Fabrication Process And Application Of Microchannel Heat Exchanger Based On Multi-blade Milling Process

Microchannel heat exchanger has been widely used in fields including aerospace,energy and chemical industry,electronic communication,and biomedicine due to clear advantages such as compact structure,high heat transfer coefficients,and reliable running status.However,microchannel is usually fabricated by MEMS and special processing,which need high demand for equipment,complex process and high cost.In this dissertation,a combined tool with stacked blades was designed to more efficiently fabricate microchannel plates,the microchannel plates were then used to assemble to Cu-based fin microchannel heat exchanger.The thermal performance and pressure drop were studied and analyzed.Main research contents are as follows:(1)Design of multi-blade milling combined tool and study on forming mechanismA combined tool with stacked blades was designed to cost-effective fabricate array microchannels.Microchannels with different sizes could be obtained by varying the thickness of the blade and the thickness of the gasket.Combining theoretical analysis with finite element simulation,the forming mechanism of multi-blade milling process and the process of deformation of the workpiece were analyzed.(2)Study and optimization on process parameters of multi-blade milling microchannelsCombining processing experiment with finite element simulation,the influence of process parameters on microchannel geometry was investigated.To ensure the smaller error of microchannel as well as high processing efficiency and low cost,a set of optimized processing parameters were obtained as follows:the cutting depth was 1.0mm,the feed rate was 180 mm/min,and the cutting speed was 251.2m/min.Compared with traditional micro milling,multi-blade milling exhibited advantages such as lower cost,hingh processing efficiency,large-scale popularization and application.(3)Design of Cu-based fin microchannel heat exchanger and test systemCu-based fin microchannel heat exchanger was designed based on multi-blade milling process.Microchannel plates with different structural parameters were fabricated,whose specific surface area were also analyzed.To ensure larger specific surface area,the better range of microchannel geometry was obtained as follows:the width was 0.4-0.6mm,the depth was 1.5-2.0mm,the spacing was 0.4-0.6mm.The performance test system was built and the evaluation of the thermal performance of microchannel heat exchanger was determined.(4)Numerical simulation and experimental study on Cu-based fin microchannel heat exchangerCombining CFD simulation with experiment,the influence of microchannel geometry,cross-sectional shape and material on the thermal performance of microchannel heat exchanger was investigated.The optimal microchannel geometry was obtained as follows:the width was 0.4mm,the depth was 2.0mm,the spacing was 0.4mm.With the Optimal thermal performance of Cu-based fin microchannel heat exchanger:When the flow rate was 900 ml/min,the heat transfer coefficient per unit volume could reach 10.92 MW/m3K and pressure drop was 2.3 kPa.