密闭机箱风冷散热结构设计与分析

文中以在严酷环境条件下使用的某型便携式电子设备为研究对象，结合传统机箱结构，设计出一款在高温环境下强迫风冷散热的密闭机箱。通过中空盖板设计，让气流在中空盖板内流动，以提高发热芯片与空气的换热速度，有效地降低整机设备及内部模块的温度，保证设备在湿热、盐雾、淋雨、高温等恶劣环境下能长时间正常工作。为了验证该强迫空冷散热设计的可实施性和量化设计指标，利用ANSYS Fluent软件对其结构装置在不同环境温度和风扇功率下的散热效果进行了三维仿真。仿真结果表明，中空盖板内的最优通风风速为1.5 m/s，该通风风速可使密闭机箱的散热效果与电能消耗达到最优平衡。

Design and Analysis of Air Cooling Heat Dissipation Structure of Fully-closed Case

A dust-proof fully closed case with forced air cooling capacity is designed in this paper based on a certain type of portable electronic equipment which will be put into use in the harsh environment. With this design, the fan-generated air current can flow through the hollow plates to increase the heat transfer speed between electronic chips and atmosphere and decrease the temperatures of the whole system and the modules in it, thereby to maintain long-time normal work of the whole system under all kinds of harsh environment such as hot & humid, rainny weather, salty environment or under high temperature. To validate the practicability of this forced air cooling design and quantify the design specification for this type of forced air cooling design, a three-dimension simulation for heat dissipation effect under different environment temperatures and fan powers is carried out by ANSYS Fluent software. The simulation result shows that the optimal air velocity inside the hollow plates is 1.5 m/s, which can reach the equilibrium of the heat dumping performance of the cooling system and power consumption of the fans.