Research On Intelligent Thermal Control System Based On Microchannel Phase Change Heat Transfer

Microchannel phase change heat transfer,as a new and efficient heat dissipation method,solves the thermal reliability problem of electronic equipment with high heat flux density.Meet the three development trends of high performance,miniaturization and integration of electronic equipment.As a new and efficient heat dissipation method,due to its small size,there are many new characteristics in heat and mass transfer that are different from the conventional channel heat dissipation,and its internal heat transfer mechanism has attracted the attention of many researchers.However,due to the complexity of the mechanism of flow and heat transfer in microchannel,the research on fluid flow boiling heat transfer in microchannel is not complete.In order to apply microchannel radiator in engineering,this paper will study and explore it.Firstly,a microchannel phase change radiator is designed and a test platform is built to test its heat transfer characteristics.Water and ethanol are used as working fluids to carry out experiments.In the experiments,the working mass flow rate ranges from 20 mL/min to 200 mL/min,and the heated flow density ranges from 50 KW/m~2to 30 KW/m~2.The temperature distribution,pressure drop and heat transfer coefficient of the radiator are tested to study its heat transfer law.On the basis of a large number of experiments,a mathematical model is proposed to calculate the temperature and heat transfer coefficient of radiator under different conditions,providing guidance for its application in engineering.According to the working principle and heat transfer characteristics of the designed microchannel heat sink,a design scheme of intelligent thermal control system is proposed.FPGA is used as the core control board,DS18B20 sensing is used to collect temperature information,flow pump is used as the controlled object,temperature signals and control signals are transmitted through serial communication mode,and all components work together to realize automatic adjustment of heat dissipation capacity of the heat sink.Solve the thermal reliability problem of electronic equipment sensitive to temperature and high heat flux density.Finally,in order to test the heat dissipation capability of the designed radiator and study the internal temperature distribution of the chassis in a closed environment,the chassis is designed and manufactured.The temperature sensor array is arranged inside the chassis to collect the temperature values of different points inside the chassis,and the upper computer software is used to monitor the internal temperature changes of the chassis in real time.After the chassis is manufactured,the heat dissipation performance of the radiator is tested and the chassis temperature value is collected without adding the radiator or with adding the radiator.Finally,the collected temperature values are processed by MATLAB software to obtain a3-dimensional map of the cabinet space temperature distribution.