Ways to improve the efficiency of cooled radiators of electronic equipment manufactured using deep drilling technology

Abstract

This article discusses the option of increasing the thermal efficiency of cooling radiators for electronic equipment manufactured using deep drilling technology. It is proposed to use electrical discharge machining technology to increase the efficiency of deep drilling channels. In a plate made of aluminum alloy, round holes are drilled along the entire length of the workpiece. Then wire for electrical erosion processing is fed into the round hole, which makes it possible to obtain a cross-section with a larger heat transfer area. The article discusses five options for sections of increased area. The heat removal efficiency for each of the cooling channel cross-section options was considered by modeling in the Solid Works Flow Simulation software environment. Distilled water was used as a coolant. The volumetric coolant flow rate is 0.8 liters per minute. The coolant temperature and the ambient temperature are equal to 25 degrees Celsius. The study considers a 30-watt thermal equivalent. The simulation results show that an increase in the heat exchange area in cooled radiators makes it possible to reduce the thermal equivalent temperature in a steady state, which indicates an increase in the thermal efficiency of the radiator. To confirm the modeling results, test the manufacturing technology and use of radiators with deep drilling, a thermal mock-up was made. Tests of the thermal model were carried out under conditions that best corresponded to the modeling conditions. A comparison of the results of modeling and experiment shows that the values obtained as a result of the experiment exceed the values obtained from modeling in all cases. The excess value ranges from 4.7 degrees to 7.4 degrees and is associated with the presence of an air gap between the copper plate and the radiator plate, the actual value of which exceeds the value of the calculation model. Analysis of the research results shows that the considered method of refining cooling channels obtained by deep drilling does not allow obtaining a qualitative increase in efficiency; the difference between the best and worst results does not exceed 3°C. The benefits obtained by this modification amount to a few degrees, which indicates the limited use of this method.