| With the rapid development of marine electronic power transformation technology in recent years,both the data processing center of the ship manufacturing industry and the interior of the ship are equipped with a large number of electrical and electronic equipment.Due to the relatively small internal environmental space of ships and the compact layout of electronic devices,the heat dissipation problem of electronic devices is particularly prominent.As a new type of heat pipe,the vapor chamber has good heat transfer capacity and temperature equalization performance.It can realize high-efficiency heat exchange,and can be widely used in marine electronic and electrical equipment.The heat transfer performance of the vapor chamber is affected by the structure of its capillary wick.Therefore,this paper uses the copper powder sintered capillary wick to make the vapor chamber,and conducts the following research work on it:According to the existing processing and manufacturing technology of the vapor chamber,combined with the actual situation,the copper powder sintered vapor chamber is produced,in which the capillary wick structure of the evaporation surface is sintered with copper powder of different particle sizes,and the capillary wick of the condensing surface is sintered with 120μm irregular shaped copper powder;And explored the feasibility of a welding process for the upper and lower shells of the vapor chamber and the liquid-filled tube,avoiding the need for high-temperature oxidation of the vapor chamber after the brazing of the liquid-filled tube The overall annealing reduction problem saves production time.Aiming at the capillary core structure made of sintered copper powder,a capillary performance test bench was built to study its capillary performance in detail,and to compare and analyze the influence of copper powders of different particle sizes and shapes on the capillary performance of the capillary core.The results show that the capillary performance of a single particle size copper powder capillary core is not linear with the particle size,but there is an optimal value;at the same time,the capillary performance of the capillary core sample with a large particle size is still better than that of the mixed sample of two small particle sizes.Capillary performance.Taking the sintered copper powder type uniform temperature plate as the research object,a test bench for the heat transfer performance of the uniform temperature plate was built.The experimental results show that the VC-90μm and VC-120μm uniform temperature plates have lower axial thermal resistance when the filling rate is 100%,but for VC-30μm and VC-50μm at the filling rate of 70%,the thermal resistance is low.At the same time,it is found that when the cooling water temperature is increased from 10°C to 25°C,the average temperature thermal resistance of the 30μm and 50μm samples decreases significantly,and the heat transfer performance of the 90μm and 120μm samples increases slightly;in addition,the experiment found After the improved process,the heat transfer performance of the uniform temperature plate has been significantly improved.The minimum thermal resistance of VC-120μm is 0.071°C/W,and the minimum thermal resistance of VC-50μm is0.109°C/W.Using 30μm and 120μm copper powder to make a visual uniform temperature plate,a visual observation experiment platform was built,and the visual phenomena of the two samples under different powers were observed at a high magnification by a high-speed camera.Under low heating power,it was observed that both samples had capillary liquid boiling.The bubbles in the VC-120μm capillary core of the sample were obviously larger than the size of the bubbles in the VC-30μm capillary core of the sample,but the growth of the bubbles was broken The period is longer than the sample VC-30μm.Under high heating power,no capillary liquid boiling phenomenon is found.According to the thermal resistance diagram,the phase change mechanism at this time is inferred to be the thin liquid film evaporation mode. |
