Experimental Study On Thermal Performance Of Flat Heat Pipe With Based On Thermal Flow Sensors

Flat micro heat pipe is good heat transfer components, the state of steam flow within the tube is one of important physical parameters for evaluating the micro heat pipe's heat transfer property. Due to the size of flat micro heat pipe is strictly limited, so far people still get distribution of axial flow velocity of internal steam of micro heat pipe in theory through modeling and calculation, which lack of experimental verification. This article attempts to carry out the measurement of internal stream flow data for the flat micro heat pipe, hoping to provide effective experimental data of flat micro heat pipe for future studies.This paper gives the structure of thermal micro flow sensor based on elaborating heat transfer mechanism of the flat micro heat pipe and measuring principle of thermal micro flow sensor, and makes the glass cover plate integrated with micro flow sensor, glass ring and triangle grooves on silicon micro heat pipe chip by using the MEMS technology. Then the above-mentioned chip sealed with a sandwich structure to make the flat micro heat pipe integrated with micro flow sensor. After those operation, this paper builds the micro flow sensor detection system on the basis of the improvement of the detection circuit design, after calibration of the temperature sensor, this paper detects the different distribution of temperature filed of the heater under different environment temperature and gets the optimum testing conditions of micro flow sensor, then the micro flow sensor optimal assay conditions was got and thermal micro flow sensor was calibrated. Finally the steam flow of evaporator section, adiabatic section and condenser section was measured inside the flat micro heat pipe.Test results show that the working substance steam flow of adiabatic section is greater than evaporation section and condensation section and at the same time steam flow in the evaporation section is slightly larger than that of the condensation segment under the same heating power; the working substance steam flow in micro heat pipe increased with the increase of heating power in the evaporation section whichever the section is, and experimental results are in good agreement with theory.