Analysis And Optimization Of Fluid-solid Coupling Heat Transfer In Air-cooled Electronic Chassis

With the development of the electronic industry,the application of electronic devices are becoming more and more widely,and they are gradually developing towards high power and miniaturization.In the limited installation space,the heat generated by the electronic devices requires the protection of the heat dissipation system,which puts forward higher requirements for the design of the heat dissipation system.Forced air-cooled heat dissipation system has many advantages such as mature technology,simple structure,safety,reliability,low cost,and easy installation etc.It is a widely used heat dissipation system for heat dissipation of electronic equipment.In this paper,the forced air cooling system of the BKSC-42P2GS1 driver is considered as the research object.Combining the structural characteristics of the limited space of the system model,through the establishment of flow-solid coupling model of axial flow fan YM2406PTB1 and IGBT module,radiator,etc.Using the method of matching the air flow field with the temperature field,the flow characteristics and heat transfer characteristics of the heat dissipation system of the equipment are studied in depth.The main research contents are as follows:(1)The air velocity distribution of the axial section of the axial fan YM2406PTB1 used in the air cooling system of the electronic equipment was analyzed.The air flow field at the outlet section was simulated,it is concluded that the air flow direction of the fan outlet section is not parallel to the axial direction,instead,it has axial velocity,radial velocity,and circumferential velocity at the same time,which rotate out along the outlet section and diffuse outward in the radial direction.It provides references for the optimization of forced air cooling system.(2)According to the parameters provided by the data and the mechanism of power loss for IGBT module,the thermal power consumption of the FP25R12KT3 IGBT module is analyzed,and the power losses of the inverter,brake-chopper and rectifier in the module are estimated respectively.Established a fluid-solid coupling model integrating the fan and IGBT module and heat sink,explored the matching relationship between the flow field and the temperature field,analyzed the existing heat dissipation system,and proposed three optimized solutions for the existing heat dissipation system.The liquid cooling system,the optimal position for designing the fan,and the optimization of the radiating fin structure were analyzed briefly,providing a reference for the optimization of the entire cooling system.(3)The distribution law of the local surface heat transfer coefficient(hx)of a flat wall which is placed in a rectangular box when using the axial-flow heat-dissipating fans is studied.The results show that the hx distribution law also change when only change the position of the circuit board vertical,When the circuit board parallel cooling fan center axis placed horizontally,and the long side of the circuit board and the cooling fan center axis parallel,firstly decreased and then increased along the length of the circuit board,the change of the vertical position of the circuit board mainly affects the variation law along the width of the circuit board,and with the distance from the hub center increased,the circuit board on the higher temperature along the width of the circuit board in the direction of the circuit board to move the edge.Which can provide an important basis for the installation of the cooling fan and the thermal design of the circuit board,it has great significance to the thermal design of electronic equipment.(4)Based on the integrated calculation model of forced air-cooled cooling system,under the condition of the radiator overall size unchanged,the structure of the radiator is optimized,by wavy fins and grooved surface design.The surface heat transfer characteristics and flow characteristics of the sheet were compared with those of the prototype fins to discuss the heat transfer characteristics of the surfaces of the different fins.The results show that both the wavy shape of the fins and the grooving can increase the radiating area of the fins.The heat transfer performance can provide reference for thermal design work.